1
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Thoenen L, Giroud C, Kreuzer M, Waelchli J, Gfeller V, Deslandes-Hérold G, Mateo P, Robert CAM, Ahrens CH, Rubio-Somoza I, Bruggmann R, Erb M, Schlaeppi K. Bacterial tolerance to host-exuded specialized metabolites structures the maize root microbiome. Proc Natl Acad Sci U S A 2023; 120:e2310134120. [PMID: 37878725 PMCID: PMC10622871 DOI: 10.1073/pnas.2310134120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/21/2023] [Indexed: 10/27/2023] Open
Abstract
Plants exude specialized metabolites from their roots, and these compounds are known to structure the root microbiome. However, the underlying mechanisms are poorly understood. We established a representative collection of maize root bacteria and tested their tolerance against benzoxazinoids (BXs), the dominant specialized and bioactive metabolites in the root exudates of maize plants. In vitro experiments revealed that BXs inhibited bacterial growth in a strain- and compound-dependent manner. Tolerance against these selective antimicrobial compounds depended on bacterial cell wall structure. Further, we found that native root bacteria isolated from maize tolerated the BXs better compared to nonhost Arabidopsis bacteria. This finding suggests the adaptation of the root bacteria to the specialized metabolites of their host plant. Bacterial tolerance to 6-methoxy-benzoxazolin-2-one (MBOA), the most abundant and selective antimicrobial metabolite in the maize rhizosphere, correlated significantly with the abundance of these bacteria on BX-exuding maize roots. Thus, strain-dependent tolerance to BXs largely explained the abundance pattern of bacteria on maize roots. Abundant bacteria generally tolerated MBOA, while low abundant root microbiome members were sensitive to this compound. Our findings reveal that tolerance to plant specialized metabolites is an important competence determinant for root colonization. We propose that bacterial tolerance to root-derived antimicrobial compounds is an underlying mechanism determining the structure of host-specific microbial communities.
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Affiliation(s)
- Lisa Thoenen
- Institute of Plant Sciences, University of Bern, Bern3013, Switzerland
- Department of Environmental Sciences, University of Basel, Basel4056, Switzerland
| | - Caitlin Giroud
- Department of Environmental Sciences, University of Basel, Basel4056, Switzerland
| | - Marco Kreuzer
- Interfaculty Bioinformatics Unit, University of Bern, Bern3012, Switzerland
| | - Jan Waelchli
- Department of Environmental Sciences, University of Basel, Basel4056, Switzerland
| | - Valentin Gfeller
- Institute of Plant Sciences, University of Bern, Bern3013, Switzerland
| | | | - Pierre Mateo
- Institute of Plant Sciences, University of Bern, Bern3013, Switzerland
| | | | - Christian H. Ahrens
- Method Development and Analytics, Group Molecular Ecology, Agroscope, Zürich8046, Switzerland
| | - Ignacio Rubio-Somoza
- Molecular Reprogramming and Evolution Lab, Centre for Research in Agricultural Genomics, Barcelona08193, Spain
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit, University of Bern, Bern3012, Switzerland
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Bern3013, Switzerland
| | - Klaus Schlaeppi
- Institute of Plant Sciences, University of Bern, Bern3013, Switzerland
- Department of Environmental Sciences, University of Basel, Basel4056, Switzerland
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2
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Hug S, Heiniger B, Bolli K, Paszti S, Eberl L, Ahrens CH, Pessi G. Paraburkholderia sabiae Uses One Type VI Secretion System (T6SS-1) as a Powerful Weapon against Notorious Plant Pathogens. Microbiol Spectr 2023; 11:e0162223. [PMID: 37439699 PMCID: PMC10434147 DOI: 10.1128/spectrum.01622-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/21/2023] [Indexed: 07/14/2023] Open
Abstract
Paraburkholderia sabiae LMG24235 is a nitrogen-fixing betaproteobacterium originally isolated from a root nodule of Mimosa caesalpiniifolia in Brazil. We show here that this strain effectively kills strains from several bacterial families (Burkholderiaceae, Pseudomonadaceae, Enterobacteriaceae) which include important plant pathogens in a contact-dependent manner. De novo assembly of the first complete genome of P. sabiae using long sequencing reads and subsequent annotation revealed two gene clusters predicted to encode type VI secretion systems (T6SS), which we named T6SS-1 and T6SS-3 according to previous classification methods (G. Shalom, J. G. Shaw, and M. S. Thomas, Microbiology, 153:2689-2699, 2007, https://doi.org/10.1099/mic.0.2007/006585-0). We created P. sabiae with mutations in each of the two T6SS gene clusters that abrogated their function, and the T6SS-1 mutant was no longer able to outcompete other strains in a contact-dependent manner. Notably, our analysis revealed that T6SS-1 is essential for competition against several important plant pathogens in vitro, including Burkholderia plantarii, Ralstonia solanacearum, Pseudomonas syringae, and Pectobacterium carotovorum. The 9-log reduction in P. syringae cells in the presence of P. sabiae was particularly remarkable. Importantly, in an in vivo assay, P. sabiae was able to protect potato tubers from bacterial soft rot disease caused by P. carotovorum, and this protection was partly dependent on T6SS-1. IMPORTANCE Rhizobia often display additional beneficial traits such as the production of plant hormones and the acquisition of limited essential nutrients that improve plant growth and enhance plant yields. Here, we show that the rhizobial strain P. sabiae antagonizes important phytopathogens such as P. carotovorum, P. syringae, and R. solanacearum and that this effect is due to contact-dependent killing mediated by one of two T6SS systems identified in the complete, de novo assembled genome sequence of P. sabiae. Importantly, co-inoculation of Solanum tuberosum tubers with P. sabiae also resulted in a drastic reduction of soft rot caused by P. carotovorum in an in vivo model system. This result highlights the protective potential of P. sabiae against important bacterial plant diseases, which makes it a valuable candidate for application as a biocontrol agent. It also emphasizes the particular potential of rhizobial inoculants that combine several beneficial effects such as plant growth promotion and biocontrol for sustainable agriculture.
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Affiliation(s)
- Sebastian Hug
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
| | - Benjamin Heiniger
- Agroscope – Molecular Ecology, Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Kim Bolli
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
| | - Sarah Paszti
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
| | - Christian H. Ahrens
- Agroscope – Molecular Ecology, Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zürich, Zurich, Switzerland
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3
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Meier-Credo J, Heiniger B, Schori C, Rupprecht F, Michel H, Ahrens CH, Langer JD. Detection of Known and Novel Small Proteins in Pseudomonas stutzeri Using a Combination of Bottom-Up and Digest-Free Proteomics and Proteogenomics. Anal Chem 2023; 95:11892-11900. [PMID: 37535005 PMCID: PMC10433244 DOI: 10.1021/acs.analchem.3c00676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/24/2023] [Indexed: 08/04/2023]
Abstract
Small proteins of around 50 aa in length have been largely overlooked in genetic and biochemical assays due to the inherent challenges with detecting and characterizing them. Recent discoveries of their critical roles in many biological processes have led to an increased recognition of the importance of small proteins for basic research and as potential new drug targets. One example is CcoM, a 36 aa subunit of the cbb3-type oxidase that plays an essential role in adaptation to oxygen-limited conditions in Pseudomonas stutzeri (P. stutzeri), a model for the clinically relevant, opportunistic pathogen Pseudomonas aeruginosa. However, as no comprehensive data were available in P. stutzeri, we devised an integrated, generic approach to study small proteins more systematically. Using the first complete genome as basis, we conducted bottom-up proteomics analyses and established a digest-free, direct-sequencing proteomics approach to study cells grown under aerobic and oxygen-limiting conditions. Finally, we also applied a proteogenomics pipeline to identify missed protein-coding genes. Overall, we identified 2921 known and 29 novel proteins, many of which were differentially regulated. Among 176 small proteins 16 were novel. Direct sequencing, featuring a specialized precursor acquisition scheme, exhibited advantages in the detection of small proteins with higher (up to 100%) sequence coverage and more spectral counts, including sequences with high proline content. Three novel small proteins, uniquely identified by direct sequencing and not conserved beyond P. stutzeri, were predicted to form an operon with a conserved protein and may represent de novo genes. These data demonstrate the power of this combined approach to study small proteins in P. stutzeri and show its potential for other prokaryotes.
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Affiliation(s)
- Jakob Meier-Credo
- Proteomics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Benjamin Heiniger
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Christian Schori
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Fiona Rupprecht
- Proteomics, Max Planck Institute for Brain
Research, 60438 Frankfurt
am Main, Germany
| | - Hartmut Michel
- Department
of Molecular Membrane Biology, Max Planck
Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Christian H. Ahrens
- Molecular
Ecology, Agroscope & SIB Swiss Institute
of Bioinformatics, 8046 Zürich, Switzerland
| | - Julian D. Langer
- Proteomics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Proteomics, Max Planck Institute for Brain
Research, 60438 Frankfurt
am Main, Germany
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4
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Stucky T, Hochstrasser M, Meyer S, Segessemann T, Ruthes AC, Ahrens CH, Pelludat C, Dahlin P. A Novel Robust Screening Assay Identifies Pseudomonas Strains as Reliable Antagonists of the Root-Knot Nematode Meloidogyne incognita. Microorganisms 2023; 11:2011. [PMID: 37630571 PMCID: PMC10459205 DOI: 10.3390/microorganisms11082011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
Forty-four bacterial strains isolated from greenhouse soil and beetroots were tested for their antagonistic activity against the plant-parasitic root-knot nematode (RKN) Meloidogyne incognita, which causes significant yield losses in a number of important crops worldwide. Through a novel combination of in vitro and on planta screening assays, Pseudomonas spp. 105 and 108 were identified as the most promising bacterial isolates. Both strains were evaluated for their potential to control different RKN population densities and as root protectants against nematode infestation. Regardless of the application method, both strains significantly reduced root galling caused by M. incognita. These two strains were subjected to whole genome sequencing and de novo genome assembly as a basis for phylogenetic and future functional characterization. Phylogenetic analysis revealed that both Pseudomonas strains cluster within the Pseudomonas fluorescens clade among previously characterized RKN antagonists and Pseudomonas-based biocontrol agents of plant diseases.
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Affiliation(s)
- Tobias Stucky
- Entomology and Nematology, Plant Protection, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Miro Hochstrasser
- Entomology and Nematology, Plant Protection, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Silvan Meyer
- Entomology and Nematology, Plant Protection, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Tina Segessemann
- Method Development and Analytics, Agroscope, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | | | - Christian H. Ahrens
- Method Development and Analytics, Agroscope, Reckenholzstrasse 190, 8046 Zürich, Switzerland
- Swiss Institute of Bioinformatics—SIB, Reckenholzstrasse 190, 8046 Zurich, Switzerland
| | - Cosima Pelludat
- Virology, Bacteriology and Phytoplasmology, Plant Protection, Agroscope, 1260 Nyon, Switzerland
| | - Paul Dahlin
- Entomology and Nematology, Plant Protection, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
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5
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Nägeli L, Schuler M, Segessemann T, Frei D, Frey JE, Wolfe KH, Ahrens CH, Freimoser FM. Genome sequence data of the strongly antagonistic yeast Pichia kluyveri isolate APC 11.10 B as a foundation for analysing biocontrol mechanisms. Data Brief 2023; 49:109394. [PMID: 37496519 PMCID: PMC10365976 DOI: 10.1016/j.dib.2023.109394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/30/2023] [Accepted: 07/05/2023] [Indexed: 07/28/2023] Open
Abstract
Pichia kluyveri strain APC 11.10 B was isolated from apple bark in Switzerland and exhibited strong antagonistic activity against plant pathogenic fungi in vitro (e.g., Botrytis, Fusarium or Monilinia isolates). In order to identify the mechanisms underlying this antagonism, we have sequenced the genome of this isolate by long- and short-read sequencing technologies. The sequence data were de novo assembled into nine scaffolds and a fully resolved circularized mitogenome. The total genome size was 10.9 Mbp and 7451 potential open reading frames (ORFs) and 202 tRNA genes were predicted. In comparison to two P. kluyveri genomes deposited at the NCBI (of strains X31-10 and CBA6002), the APC 11.10 B strain seemed to represent a hybrid because backmapping of sequencing reads resulted in a high rate of heterozygous and structural variants in the nuclear genome (this was not observed for the mitochondrial genome). The P. kluyveri (APC 11.10 B) draft genome represents a first step and resource for genome mining, comparative and functional genomics (e.g., identifying the biocontrol mode of action), and evolutionary studies. Since the genus Pichia comprises many biotechnologically relevant yeasts, the genome data may be used in a variety of fields and disciplines.
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Affiliation(s)
- Lukas Nägeli
- Agroscope, Research Division Plant Protection, Route de Duillier 60, 1260 Nyon 1, Switzerland
| | - Martin Schuler
- Agroscope, Competence Division Method Development and Analytics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | - Tina Segessemann
- Agroscope, Competence Division Method Development and Analytics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
- SIB, Swiss Institute of Bioinformatics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | - Daniel Frei
- Agroscope, Competence Division Method Development and Analytics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | - Jürg E. Frey
- Agroscope, Competence Division Method Development and Analytics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | | | - Christian H. Ahrens
- Agroscope, Competence Division Method Development and Analytics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
- SIB, Swiss Institute of Bioinformatics, Reckenholzstrasse 190, 8046 Zürich, Switzerland
| | - Florian M. Freimoser
- Agroscope, Research Division Plant Protection, Route de Duillier 60, 1260 Nyon 1, Switzerland
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6
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Romanò A, Ivanovic I, Segessemann T, Vazquez Rojo L, Widmer J, Egger L, Dreier M, Sesso L, Vaccani M, Schuler M, Frei D, Frey J, Ahrens CH, Steiner A, Graber HU. Elucidation of the Bovine Intramammary Bacteriome and Resistome from healthy cows of Swiss dairy farms in the Canton Tessin. Front Microbiol 2023; 14:1183018. [PMID: 37583512 PMCID: PMC10425240 DOI: 10.3389/fmicb.2023.1183018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/26/2023] [Indexed: 08/17/2023] Open
Abstract
Healthy, untreated cows of nine dairy herds from the Swiss Canton Tessin were analyzed three times within one year to identify the most abundant species of the intramammary bacteriome. Aseptically collected milk samples were cultured and bacteria identified using MALDI-TOF. Of 256 cows analyzed, 96% were bacteriologically positive and 80% of the 1,024 quarters were positive for at least one bacterial species. 84.5% of the quarters were healthy with somatic cell counts (SCC) < 200,000 cells/mL, whereas 15.5% of the quarters showed a subclinical mastitis (SCC ≥ 200,000 cells/mL). We could assign 1,288 isolates to 104 different bacterial species including 23 predominant species. Non-aureus staphylococci and mammaliicocci (NASM) were most prevalent (14 different species; 73.5% quarters). Staphylococcus xylosus and Mammaliicoccus sciuri accounted for 74.7% of all NASM isolates. To describe the intramammary resistome, 350 isolates of the predominant species were selected and subjected to short-read whole genome sequencing (WGS) and phenotypic antibiotic resistance profiling. While complete genomes of eight type strains were available, the remaining 15 were de novo assembled with long reads as a resource for the community. The 23 complete genomes served for reference-based assembly of the Illumina WGS data. Both chromosomes and mobile genetic elements were examined for antibiotic resistance genes (ARGs) using in-house and online software tools. ARGs were then correlated with phenotypic antibiotic resistance data from minimum inhibitory concentration (MIC). Phenotypic and genomic antimicrobial resistance was isolate-specific. Resistance to clindamycin and oxacillin was most frequently observed (65 and 30%) in Staphylococcus xylosus but could not be linked to chromosomal or plasmid-borne ARGs. However, in several cases, the observed antimicrobial resistance could be explained by the presence of mobile genetic elements like tetK carried on small plasmids. This represents a possible mechanism of transfer between non-pathogenic bacteria and pathogens of the mammary gland within and between herds. The-to our knowledge-most extensive bacteriome reported and the first attempt to link it with the resistome promise to profoundly affect veterinary bacteriology in the future and are highly relevant in a One Health context, in particular for mastitis, the treatment of which still heavily relies on antibiotics.
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Affiliation(s)
- Alicia Romanò
- Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, Agroscope, Bern, Switzerland
- Graduate School of Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ivana Ivanovic
- Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, Agroscope, Bern, Switzerland
| | - Tina Segessemann
- SIB, Swiss Institute of Bioinformatics, Zürich, Switzerland
- Method Development and Analytics, Group Molecular Ecology, Agroscope, Zürich, Switzerland
| | - Laura Vazquez Rojo
- Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, Agroscope, Bern, Switzerland
| | - Jérôme Widmer
- Method Development and Analytics, Group Biochemistry of Milk, Agroscope, Bern, Switzerland
| | - Lotti Egger
- Method Development and Analytics, Group Biochemistry of Milk, Agroscope, Bern, Switzerland
| | - Matthias Dreier
- Food Microbial Systems, Group Cultures, Biodiversity, and Terroir, Agroscope, Bern, Switzerland
| | - Lorenzo Sesso
- Clinic of Ruminants, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Michael Vaccani
- Clinic of Ruminants, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Martin Schuler
- SIB, Swiss Institute of Bioinformatics, Zürich, Switzerland
- Method Development and Analytics, Group Molecular Ecology, Agroscope, Zürich, Switzerland
| | - Daniel Frei
- Method Development and Analytics, Group Molecular Diagnostics, Genomics, and Bioinformatics, Agroscope, Wädenswil, Switzerland
| | - Juerg Frey
- Method Development and Analytics, Group Molecular Diagnostics, Genomics, and Bioinformatics, Agroscope, Wädenswil, Switzerland
| | - Christian H. Ahrens
- SIB, Swiss Institute of Bioinformatics, Zürich, Switzerland
- Method Development and Analytics, Group Molecular Ecology, Agroscope, Zürich, Switzerland
| | - Adrian Steiner
- Clinic of Ruminants, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Hans Ulrich Graber
- Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, Agroscope, Bern, Switzerland
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7
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Rueda-Mejia MP, Bühlmann A, Ortiz-Merino RA, Lutz S, Ahrens CH, Künzler M, Freimoser FM. Pantothenate Auxotrophy in a Naturally Occurring Biocontrol Yeast. Appl Environ Microbiol 2023:e0088423. [PMID: 37404169 PMCID: PMC10370309 DOI: 10.1128/aem.00884-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023] Open
Abstract
The genus Hanseniaspora is characterized by some of the smallest genomes among budding yeasts. These fungi are primarily found on plant surfaces and in fermented products and represent promising biocontrol agents against notorious fungal plant pathogens. In this work, we identify pantothenate auxotrophy of a Hanseniaspora meyeri isolate that shows strong antagonism against the plant pathogen Fusarium oxysporum. Furthermore, strong biocontrol activity in vitro required both pantothenate and biotin in the growth medium. We show that the H. meyeri isolate APC 12.1 can obtain the vitamin from plants and other fungi. The underlying reason for the auxotrophy is the lack of two key pantothenate biosynthesis genes, but six genes encoding putative pantothenate transporters are present in the genome. By constructing and using a Saccharomyces cerevisiae reporter strain, we identified one Hanseniaspora transporter that conferred pantothenate uptake activity to S. cerevisiae. Pantothenate auxotrophy is rare and has been described in only a few bacteria and in S. cerevisiae strains that were isolated from sake. Such auxotrophic strains may seem an unexpected and unlikely choice as potential biocontrol agents, but they may be particularly competitive in their ecological niche and their specific growth requirements are an inherent biocontainment strategy preventing uncontrolled growth in the environment. Auxotrophic strains, such as the H. meyeri isolate APC 12.1, may thus represent a promising strategy for developing biocontrol agents that will be easier to register than prototrophic strains, which are normally used for such applications. IMPORTANCE As a precursor of the essential coenzyme A (CoA), pantothenate is present in all organisms. Plants, bacteria, and fungi are known to synthesize this vitamin, while animals must obtain it through their diet. Pantothenate auxotrophy has not been described in naturally occurring, environmental fungi and is an unexpected property for an antagonistic yeast. Here, we report that yeasts from the genus Hanseniaspora lack key enzymes for pantothenate biosynthesis and identify a transporter responsible for the acquisition of pantothenate from the environment. Hanseniaspora isolates are strong antagonists of fungal plant pathogens. Their pantothenate auxotrophy is a natural biocontainment feature that could make such isolates interesting candidates for new biocontrol approaches and allow easier registration as plant protection agents than prototrophic strains.
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Affiliation(s)
| | - Andreas Bühlmann
- Agroscope, Research Division Food Microbial Systems, Wädenswil, Switzerland
| | | | - Stefanie Lutz
- Conway Institute, University College Dublin, Dublin, Ireland
- Agroscope, Competence Division Method Development and Analytics, Zürich, Switzerland
| | - Christian H Ahrens
- Agroscope, Competence Division Method Development and Analytics, Zürich, Switzerland
- SIB, Swiss Institute of Bioinformatics, Zürich, Switzerland
| | - Markus Künzler
- Institute of Microbiology, Department of Biology, ETH Zürich, Zürich, Switzerland
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8
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Hadjeras L, Heiniger B, Maaß S, Scheuer R, Gelhausen R, Azarderakhsh S, Barth-Weber S, Backofen R, Becher D, Ahrens CH, Sharma CM, Evguenieva-Hackenberg E. Unraveling the small proteome of the plant symbiont Sinorhizobium meliloti by ribosome profiling and proteogenomics. Microlife 2023; 4:uqad012. [PMID: 37223733 PMCID: PMC10117765 DOI: 10.1093/femsml/uqad012] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/08/2023] [Accepted: 03/07/2023] [Indexed: 05/25/2023]
Abstract
The soil-dwelling plant symbiont Sinorhizobium meliloti is a major model organism of Alphaproteobacteria. Despite numerous detailed OMICS studies, information about small open reading frame (sORF)-encoded proteins (SEPs) is largely missing, because sORFs are poorly annotated and SEPs are hard to detect experimentally. However, given that SEPs can fulfill important functions, identification of translated sORFs is critical for analyzing their roles in bacterial physiology. Ribosome profiling (Ribo-seq) can detect translated sORFs with high sensitivity, but is not yet routinely applied to bacteria because it must be adapted for each species. Here, we established a Ribo-seq procedure for S. meliloti 2011 based on RNase I digestion and detected translation for 60% of the annotated coding sequences during growth in minimal medium. Using ORF prediction tools based on Ribo-seq data, subsequent filtering, and manual curation, the translation of 37 non-annotated sORFs with ≤ 70 amino acids was predicted with confidence. The Ribo-seq data were supplemented by mass spectrometry (MS) analyses from three sample preparation approaches and two integrated proteogenomic search database (iPtgxDB) types. Searches against standard and 20-fold smaller Ribo-seq data-informed custom iPtgxDBs confirmed 47 annotated SEPs and identified 11 additional novel SEPs. Epitope tagging and Western blot analysis confirmed the translation of 15 out of 20 SEPs selected from the translatome map. Overall, by combining MS and Ribo-seq approaches, the small proteome of S. meliloti was substantially expanded by 48 novel SEPs. Several of them are part of predicted operons and/or are conserved from Rhizobiaceae to Bacteria, suggesting important physiological functions.
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Affiliation(s)
- Lydia Hadjeras
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | | | | | | | - Rick Gelhausen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Saina Azarderakhsh
- Institute of Microbiology and Molecular Biology, University of Giessen, 35392 Giessen, Germany
| | - Susanne Barth-Weber
- Institute of Microbiology and Molecular Biology, University of Giessen, 35392 Giessen, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
| | - Christian H Ahrens
- Corresponding author. Molecular Ecology, Agroscope and SIB Swiss Institute of Bioinformatics, 8046 Zurich, Switzerland. E-mail:
| | - Cynthia M Sharma
- Corresponding author. Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany. E-mail:
| | - Elena Evguenieva-Hackenberg
- Corresponding author. Institute of Microbiology and Molecular Biology, University of Giessen, 35392 Giessen, Germany. E-mail:
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9
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Valentin JDP, Altenried S, Varadarajan AR, Ahrens CH, Schreiber F, Webb JS, van der Mei HC, Ren Q. Identification of Potential Antimicrobial Targets of Pseudomonas aeruginosa Biofilms through a Novel Screening Approach. Microbiol Spectr 2023; 11:e0309922. [PMID: 36779712 PMCID: PMC10100978 DOI: 10.1128/spectrum.03099-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/15/2023] [Indexed: 02/14/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen of considerable medical importance, owing to its pronounced antibiotic tolerance and association with cystic fibrosis and other life-threatening diseases. The aim of this study was to highlight the genes responsible for P. aeruginosa biofilm tolerance to antibiotics and thereby identify potential new targets for the development of drugs against biofilm-related infections. By developing a novel screening approach and utilizing a public P. aeruginosa transposon insertion library, several biofilm-relevant genes were identified. The Pf phage gene (PA0720) and flagellin gene (fliC) conferred biofilm-specific tolerance to gentamicin. Compared with the reference biofilms, the biofilms formed by PA0720 and fliC mutants were completely eliminated with a 4-fold-lower gentamicin concentration. Furthermore, the mreC, pprB, coxC, and PA3785 genes were demonstrated to play major roles in enhancing biofilm tolerance to gentamicin. The analysis of biofilm-relevant genes performed in this study provides important novel insights into the understanding of P. aeruginosa antibiotic tolerance, which will facilitate the detection of antibiotic resistance and the development of antibiofilm strategies against P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa is an opportunistic pathogen of high medical importance and is one of the main pathogens responsible for the mortality of patients with cystic fibrosis. In addition to inherited antibiotic resistance, P. aeruginosa can form biofilms, defined as communities of microorganisms embedded in a self-produced matrix of extracellular polymeric substances adhering to each other and/or to a surface. Biofilms protect bacteria from antibiotic treatments and represent a major reason for antibiotic failure in the treatment of chronic infections caused by cystic fibrosis. Therefore, it is crucial to develop new therapeutic strategies aimed at specifically eradicating biofilms. The aim of this study was to generalize a novel screening method for biofilm research and to identify the possible genes involved in P. aeruginosa biofilm tolerance to antibiotics, both of which could improve the understanding of biofilm-related infections and allow for the identification of relevant therapeutic targets for drug development.
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Affiliation(s)
- Jules D. P. Valentin
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
- University of Groningen and University Medical Center Groningen, Department of BioMedical Engineering, Groningen, Netherlands
| | - Stefanie Altenried
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Adithi R. Varadarajan
- Molecular Ecology, Agroscope and Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Christian H. Ahrens
- Molecular Ecology, Agroscope and Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Frank Schreiber
- Division of Biodeterioration and Reference Organisms (4.1), Department of Materials and the Environment, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Jeremy S. Webb
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- National Biofilms Innovation Centre, University of Southampton, Southampton, United Kingdom
| | - Henny C. van der Mei
- University of Groningen and University Medical Center Groningen, Department of BioMedical Engineering, Groningen, Netherlands
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
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10
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Bellés-Sancho P, Liu Y, Heiniger B, von Salis E, Eberl L, Ahrens CH, Zamboni N, Bailly A, Pessi G. A novel function of the key nitrogen-fixation activator NifA in beta-rhizobia: Repression of bacterial auxin synthesis during symbiosis. Front Plant Sci 2022; 13:991548. [PMID: 36247538 PMCID: PMC9554594 DOI: 10.3389/fpls.2022.991548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Rhizobia fix nitrogen within root nodules of host plants where nitrogenase expression is strictly controlled by its key regulator NifA. We recently discovered that in nodules infected by the beta-rhizobial strain Paraburkholderia phymatum STM815, NifA controls expression of two bacterial auxin synthesis genes. Both the iaaM and iaaH transcripts, as well as the metabolites indole-acetamide (IAM) and indole-3-acetic acid (IAA) showed increased abundance in nodules occupied by a nifA mutant compared to wild-type nodules. Here, we document the structural changes that a P. phymatum nifA mutant induces in common bean (Phaseolus vulgaris) nodules, eventually leading to hypernodulation. To investigate the role of the P. phymatum iaaMH genes during symbiosis, we monitored their expression in presence and absence of NifA over different stages of the symbiosis. The iaaMH genes were found to be under negative control of NifA in all symbiotic stages. While a P. phymatum iaaMH mutant produced the same number of nodules and nitrogenase activity as the wild-type strain, the nifA mutant produced more nodules than the wild-type that clustered into regularly-patterned root zones. Mutation of the iaaMH genes in a nifA mutant background reduced the presence of these nodule clusters on the root. We further show that the P. phymatum iaaMH genes are located in a region of the symbiotic plasmid with a significantly lower GC content and exhibit high similarity to two genes of the IAM pathway often used by bacterial phytopathogens to deploy IAA as a virulence factor. Overall, our data suggest that the increased abundance of rhizobial auxin in the non-fixing nifA mutant strain enables greater root infection rates and a role for bacterial auxin production in the control of early stage symbiotic interactions.
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Affiliation(s)
- Paula Bellés-Sancho
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Yilei Liu
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Benjamin Heiniger
- Agroscope, Molecular Ecology and Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Elia von Salis
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Christian H. Ahrens
- Agroscope, Molecular Ecology and Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Nicola Zamboni
- ETH Zürich, Institute of Molecular Systems Biology, Zurich, Switzerland
| | - Aurélien Bailly
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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11
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Wülser J, Ernst C, Vetsch D, Emmenegger B, Michel A, Lutz S, Ahrens CH, Vorholt JA, Ledermann R, Fischer HM. Salt- and Osmo-Responsive Sensor Histidine Kinases Activate the Bradyrhizobium diazoefficiens General Stress Response to Initiate Functional Symbiosis. Mol Plant Microbe Interact 2022; 35:604-615. [PMID: 35322688 DOI: 10.1094/mpmi-02-22-0051-fi] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The general stress response (GSR) enables bacteria to sense and overcome a variety of environmental stresses. In alphaproteobacteria, stress-perceiving histidine kinases of the HWE and HisKA_2 families trigger a signaling cascade that leads to phosphorylation of the response regulator PhyR and, consequently, to activation of the GSR σ factor σEcfG. In the nitrogen-fixing bacterium Bradyrhizobium diazoefficiens, PhyR and σEcfG are crucial for tolerance against a variety of stresses under free-living conditions and also for efficient infection of its symbiotic host soybean. However, the molecular players involved in stress perception and activation of the GSR remained largely unknown. In this work, we first showed that a mutant variant of PhyR where the conserved phosphorylatable aspartate residue D194 was replaced by alanine (PhyRD194A) failed to complement the ΔphyR mutant in symbiosis, confirming that PhyR acts as a response regulator. To identify the PhyR-activating kinases in the nitrogen-fixing symbiont, we constructed in-frame deletion mutants lacking single, distinct combinations, or all of the 11 predicted HWE and HisKA_2 kinases, which we named HRXXN histidine kinases HhkA through HhkK. Phenotypic analysis of the mutants and complemented derivatives identified two functionally redundant kinases, HhkA and HhkE, that are required for nodulation competitiveness and during initiation of symbiosis. Using σEcfG-activity reporter strains, we further showed that both HhkA and HhkE activate the GSR in free-living cells exposed to salt and hyperosmotic stress. In conclusion, our data suggest that HhkA and HhkE trigger GSR activation in response to osmotically stressful conditions which B. diazoefficiens encounters during soybean host infection.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Janine Wülser
- Institute of Microbiology, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Chantal Ernst
- Institute of Microbiology, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Dominik Vetsch
- Institute of Microbiology, ETH Zurich, CH-8093 Zürich, Switzerland
| | | | - Anja Michel
- Institute of Microbiology, ETH Zurich, CH-8093 Zürich, Switzerland
| | - Stefanie Lutz
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics and Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics and Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, ETH Zurich, CH-8093 Zürich, Switzerland
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12
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Rueda-Mejia MP, Nägeli L, Lutz S, Ortiz-Merino RA, Frei D, Frey JE, Wolfe KH, Ahrens CH, Freimoser FM. Genome sequence data of the antagonistic soil-borne yeast Cyberlindnera sargentensis (SHA 17.2). Data Brief 2022; 40:107799. [PMID: 35071701 PMCID: PMC8762083 DOI: 10.1016/j.dib.2022.107799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/03/2022] [Indexed: 10/26/2022] Open
Abstract
Cyberlindnera sargentensis strain SHA 17.2, isolated from a Swiss soil sample, exhibited strong antagonistic activity against several plant pathogenic fungi in vitro and was highly competitive against other yeasts in soil. As a basis for identifying the mechanisms underlying its strong antagonistic activity, we have sequenced the genome of C. sargentensis (SHA 17.2) by long- and short read sequencing, de novo assembled them into seven contigs/chromosomes and a mitogenome (total genome size 11.4 Mbp), and annotated 5455 genes. This high-quality genome is the reference for transcriptome and proteome analyses aiming at elucidating the mode of action of C. sargentensis against fungal plant pathogens. It will thus serve as a resource for identifying potential biocontrol genes and performing comparative genomics analyses of yeast genomes.
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Affiliation(s)
- Maria Paula Rueda-Mejia
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | - Lukas Nägeli
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | - Stefanie Lutz
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | | | - Daniel Frei
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | - Jürg E Frey
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | - Kenneth H Wolfe
- Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Christian H Ahrens
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland.,SIB, Swiss Institute of Bioinformatics, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
| | - Florian M Freimoser
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, Wädenswil 8820, Switzerland
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13
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Abstract
Small proteins of up to ∼50 amino acids are an abundant class of biomolecules across all domains of life. Yet due to the challenges inherent in their size, they are often missed in genome annotations, and are difficult to identify and characterize using standard experimental approaches. Consequently, we still know few small proteins even in well-studied prokaryotic model organisms. Mass spectrometry (MS) has great potential for the discovery, validation, and functional characterization of small proteins. However, standard MS approaches are poorly suited to the identification of both known and novel small proteins due to limitations at each step of a typical proteomics workflow, i.e., sample preparation, protease digestion, liquid chromatography, MS data acquisition, and data analysis. Here, we outline the major MS-based workflows and bioinformatic pipelines used for small protein discovery and validation. Special emphasis is placed on highlighting the adjustments required to improve detection and data quality for small proteins. We discuss both the unbiased detection of small proteins and the targeted analysis of small proteins of interest. Finally, we provide guidelines to prioritize novel small proteins, and an outlook on methods with particular potential to further improve comprehensive discovery and characterization of small proteins.
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Affiliation(s)
- Christian H. Ahrens
- Agroscope, Method Development and Analytics & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
| | - Matthew M. Champion
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Julian D. Langer
- Mass Spectrometry and Proteomics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Proteomics, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
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14
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Mayerhofer J, Thuerig B, Oberhaensli T, Enderle E, Lutz S, Ahrens CH, Fuchs JG, Widmer F. Indicative bacterial communities and taxa of disease-suppressing and growth-promoting composts and their associations to the rhizoplane. FEMS Microbiol Ecol 2021; 97:6373440. [PMID: 34549287 PMCID: PMC8478479 DOI: 10.1093/femsec/fiab134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 09/17/2021] [Indexed: 11/13/2022] Open
Abstract
Compost applications vary in their plant growth promotion and plant disease suppression, likely due to differences in physico-chemical and biological parameters. Our hypothesis was that bacteria are important for plant growth promotion and disease suppression of composts and, therefore, composts having these traits would contain similar sets of indicative bacterial taxa. Seventeen composts prepared from five different commercial providers and different starting materials were classified accordingly with bioassays using cress plants and the pathogen Pythium ultimum. Using a metabarcoding approach, bacterial communities were assessed in bulk composts and cress rhizoplanes. Six and nine composts showed significant disease suppression or growth promotion, respectively, but these traits did not correlate. Growth promotion correlated positively with nitrate content of composts, whereas disease suppression correlated negatively with factors representing compost age. Growth promotion and disease suppression explained significant portions of variation in bacterial community structures, i.e. 11.5% and 14.7%, respectively. Among the sequence variants (SVs) associated with growth promotion, Microvirga, Acinetobacter, Streptomyces, Bradyrhizobium and Bacillus were highly promising, while in suppressive composts, Ureibacillus,Thermogutta and Sphingopyxis were most promising. Associated SVs represent the basis for developing prediction tools for growth promotion and disease suppression, a highly desired goal for targeted compost production and application.
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Affiliation(s)
| | - Barbara Thuerig
- Crop Protection and Phytopathology, FiBL Research Institute of Organic Agriculture, 5070, Frick, Switzerland
| | - Thomas Oberhaensli
- Crop Protection and Phytopathology, FiBL Research Institute of Organic Agriculture, 5070, Frick, Switzerland
| | - Eileen Enderle
- Crop Protection and Phytopathology, FiBL Research Institute of Organic Agriculture, 5070, Frick, Switzerland
| | - Stefanie Lutz
- Molecular Diagnostics, Genomics and Bioinformatics, Agroscope, 8820, Wädenswil, Switzerland
| | - Christian H Ahrens
- Molecular Diagnostics, Genomics and Bioinformatics, Agroscope, 8820, Wädenswil, Switzerland.,Bioinformatics and Proteogenomics, SIB Swiss Institute of Bioinformatics, 8820, Wädenswil, Switzerland
| | - Jacques G Fuchs
- Crop Protection and Phytopathology, FiBL Research Institute of Organic Agriculture, 5070, Frick, Switzerland
| | - Franco Widmer
- Molecular Ecology, Agroscope, 8046, Zurich, Switzerland
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15
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Rueda-Mejia MP, Nägeli L, Lutz S, Hayes RD, Varadarajan AR, Grigoriev IV, Ahrens CH, Freimoser FM. Genome, transcriptome and secretome analyses of the antagonistic, yeast-like fungus Aureobasidium pullulans to identify potential biocontrol genes. Microb Cell 2021; 8:184-202. [PMID: 34395586 PMCID: PMC8329847 DOI: 10.15698/mic2021.08.757] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/27/2022]
Abstract
Aureobasidium pullulans is an extremotolerant, cosmopolitan yeast-like fungus that successfully colonises vastly different ecological niches. The species is widely used in biotechnology and successfully applied as a commercial biocontrol agent against postharvest diseases and fireblight. However, the exact mechanisms that are responsible for its antagonistic activity against diverse plant pathogens are not known at the molecular level. Thus, it is difficult to optimise and improve the biocontrol applications of this species. As a foundation for elucidating biocontrol mechanisms, we have de novo assembled a high-quality reference genome of a strongly antagonistic A. pullulans strain, performed dual RNA-seq experiments, and analysed proteins secreted during the interaction with the plant pathogen Fusarium oxysporum. Based on the genome annotation, potential biocontrol genes were predicted to encode secreted hydrolases or to be part of secondary metabolite clusters (e.g., NRPS-like, NRPS, T1PKS, terpene, and β-lactone clusters). Transcriptome and secretome analyses defined a subset of 79 A. pullulans genes (among the 10,925 annotated genes) that were transcriptionally upregulated or exclusively detected at the protein level during the competition with F. oxysporum. These potential biocontrol genes comprised predicted secreted hydrolases such as glycosylases, esterases, and proteases, as well as genes encoding enzymes, which are predicted to be involved in the synthesis of secondary metabolites. This study highlights the value of a sequential approach starting with genome mining and consecutive transcriptome and secretome analyses in order to identify a limited number of potential target genes for detailed, functional analyses.
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Affiliation(s)
- Maria Paula Rueda-Mejia
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Lukas Nägeli
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Stefanie Lutz
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Richard D Hayes
- U.S. Department of Energy Joint Genome Institute (JGI), Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, USA
| | - Adithi R Varadarajan
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute (JGI), Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, USA.,Department of Plant and Microbial Biology, University of California Berkeley, Koshland Hall, Berkeley, CA, USA
| | - Christian H Ahrens
- Agroscope, Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland.,SIB, Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Florian M Freimoser
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
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16
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Fuchs S, Kucklick M, Lehmann E, Beckmann A, Wilkens M, Kolte B, Mustafayeva A, Ludwig T, Diwo M, Wissing J, Jänsch L, Ahrens CH, Ignatova Z, Engelmann S. Towards the characterization of the hidden world of small proteins in Staphylococcus aureus, a proteogenomics approach. PLoS Genet 2021; 17:e1009585. [PMID: 34061833 PMCID: PMC8195425 DOI: 10.1371/journal.pgen.1009585] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/11/2021] [Accepted: 05/07/2021] [Indexed: 01/08/2023] Open
Abstract
Small proteins play essential roles in bacterial physiology and virulence, however, automated algorithms for genome annotation are often not yet able to accurately predict the corresponding genes. The accuracy and reliability of genome annotations, particularly for small open reading frames (sORFs), can be significantly improved by integrating protein evidence from experimental approaches. Here we present a highly optimized and flexible bioinformatics workflow for bacterial proteogenomics covering all steps from (i) generation of protein databases, (ii) database searches and (iii) peptide-to-genome mapping to (iv) visualization of results. We used the workflow to identify high quality peptide spectrum matches (PSMs) for small proteins (≤ 100 aa, SP100) in Staphylococcus aureus Newman. Protein extracts from S. aureus were subjected to different experimental workflows for protein digestion and prefractionation and measured with highly sensitive mass spectrometers. In total, 175 proteins with up to 100 aa (SP100) were identified. Out of these 24 (ranging from 9 to 99 aa) were novel and not contained in the used genome annotation.144 SP100 are highly conserved and were found in at least 50% of the publicly available S. aureus genomes, while 127 are additionally conserved in other staphylococci. Almost half of the identified SP100 were basic, suggesting a role in binding to more acidic molecules such as nucleic acids or phospholipids.
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Affiliation(s)
- Stephan Fuchs
- Robert Koch Institute, Methodenentwicklung und Forschungsinfrastruktur (MF), Berlin, Germany
| | - Martin Kucklick
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Erik Lehmann
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Alexander Beckmann
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Maya Wilkens
- Robert Koch Institute, Methodenentwicklung und Forschungsinfrastruktur (MF), Berlin, Germany
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Baban Kolte
- University of Hamburg, Institute of Biochemistry and Molecular Biology, Hamburg, Germany
| | - Ayten Mustafayeva
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Tobias Ludwig
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Maurice Diwo
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
| | - Josef Wissing
- Helmholtz Center for Infection Research GmbH, Cellular Proteomics, Braunschweig, Germany
| | - Lothar Jänsch
- Helmholtz Center for Infection Research GmbH, Cellular Proteomics, Braunschweig, Germany
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Zoya Ignatova
- University of Hamburg, Institute of Biochemistry and Molecular Biology, Hamburg, Germany
| | - Susanne Engelmann
- University of Technical Sciences Braunschweig, Institute for Microbiology, Braunschweig, Germany
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Braunschweig, Germany
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17
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Petruschke H, Schori C, Canzler S, Riesbeck S, Poehlein A, Daniel R, Frei D, Segessemann T, Zimmerman J, Marinos G, Kaleta C, Jehmlich N, Ahrens CH, von Bergen M. Discovery of novel community-relevant small proteins in a simplified human intestinal microbiome. Microbiome 2021; 9:55. [PMID: 33622394 PMCID: PMC7903761 DOI: 10.1186/s40168-020-00981-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/16/2020] [Indexed: 05/13/2023]
Abstract
BACKGROUND The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, modulating immunity and regulating metabolic processes. We studied the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species with a particular focus on the discovery of novel small proteins with less than 100 amino acids (= sProteins), some of which may contribute to shape the simplified human intestinal microbiota. Although sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. RESULTS We created a multi-species integrated proteogenomics search database (iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied to specifically increase the chances for novel sProtein discovery. The search of tandem mass spectrometry (MS/MS) data against the multi-species iPtgxDB enabled the identification of 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. The comparison of sProtein expression in each single strain versus a multi-species community cultivation showed that six of these sProteins were only identified in the SIHUMIx community indicating a potentially important role of sProteins in the organization of microbial communities. Two of these novel sProteins have a potential antimicrobial function. Metabolic modelling revealed that a third sProtein is located in a genomic region encoding several enzymes relevant for the community metabolism within SIHUMIx. CONCLUSIONS We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in a simplified intestinal model system that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the SIHUMIx multi-species community is expected to enable new insights into the role of sProteins on the functionality of bacterial communities such as those of the human intestinal tract. Video abstract.
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Affiliation(s)
- Hannes Petruschke
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ GmbH, Leipzig, Germany
| | - Christian Schori
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Sebastian Canzler
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ GmbH, Leipzig, Germany
| | - Sarah Riesbeck
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ GmbH, Leipzig, Germany
| | - Anja Poehlein
- Institute of Microbiology and Genetics, Department of Genomic and Applied Microbiology, Georg-August University of Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Institute of Microbiology and Genetics, Department of Genomic and Applied Microbiology, Georg-August University of Göttingen, Göttingen, Germany
| | - Daniel Frei
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Tina Segessemann
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Johannes Zimmerman
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Georgios Marinos
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Christoph Kaleta
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Nico Jehmlich
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ GmbH, Leipzig, Germany
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland.
| | - Martin von Bergen
- Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research - UFZ GmbH, Leipzig, Germany.
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, University of Leipzig, Leipzig, Germany.
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18
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Hug S, Liu Y, Heiniger B, Bailly A, Ahrens CH, Eberl L, Pessi G. Differential Expression of Paraburkholderia phymatum Type VI Secretion Systems (T6SS) Suggests a Role of T6SS-b in Early Symbiotic Interaction. Front Plant Sci 2021; 12:699590. [PMID: 34394152 PMCID: PMC8356804 DOI: 10.3389/fpls.2021.699590] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/28/2021] [Indexed: 05/06/2023]
Abstract
Paraburkholderia phymatum STM815, a rhizobial strain of the Burkholderiaceae family, is able to nodulate a broad range of legumes including the agriculturally important Phaseolus vulgaris (common bean). P. phymatum harbors two type VI Secretion Systems (T6SS-b and T6SS-3) in its genome that contribute to its high interbacterial competitiveness in vitro and in infecting the roots of several legumes. In this study, we show that P. phymatum T6SS-b is found in the genomes of several soil-dwelling plant symbionts and that its expression is induced by the presence of citrate and is higher at 20/28°C compared to 37°C. Conversely, T6SS-3 shows homologies to T6SS clusters found in several pathogenic Burkholderia strains, is more prominently expressed with succinate during stationary phase and at 37°C. In addition, T6SS-b expression was activated in the presence of germinated seeds as well as in P. vulgaris and Mimosa pudica root nodules. Phenotypic analysis of selected deletion mutant strains suggested a role of T6SS-b in motility but not at later stages of the interaction with legumes. In contrast, the T6SS-3 mutant was not affected in any of the free-living and symbiotic phenotypes examined. Thus, P. phymatum T6SS-b is potentially important for the early infection step in the symbiosis with legumes.
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Affiliation(s)
- Sebastian Hug
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Yilei Liu
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Benjamin Heiniger
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Aurélien Bailly
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Christian H. Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
- *Correspondence: Gabriella Pessi,
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19
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Koutsovoulos GD, Poullet M, Elashry A, Kozlowski DKL, Sallet E, Da Rocha M, Perfus-Barbeoch L, Martin-Jimenez C, Frey JE, Ahrens CH, Kiewnick S, Danchin EGJ. Author Correction: Genome assembly and annotation of Meloidogyne enterolobii, an emerging parthenogenetic root-knot nematode. Sci Data 2020; 7:413. [PMID: 33214557 PMCID: PMC7677529 DOI: 10.1038/s41597-020-00747-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A Correction to this paper has been published: https://doi.org/10.1038/s41597-020-00747-0.
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Affiliation(s)
| | - Marine Poullet
- Université Côte d'Azur, IN RAE, CNRS, Institut Sophia Agrobiotech, Sophia Antipolis, France
| | | | - Djampa K L Kozlowski
- Université Côte d'Azur, IN RAE, CNRS, Institut Sophia Agrobiotech, Sophia Antipolis, France
| | - Erika Sallet
- Laboratoire des Interactions Plantes-Microorganismes, INRAE, CNRS, 31326, Castanet-Tolosan, France
| | - Martine Da Rocha
- Université Côte d'Azur, IN RAE, CNRS, Institut Sophia Agrobiotech, Sophia Antipolis, France
| | | | | | - Juerg Ernst Frey
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Bioinformatics, Wädenswil, Switzerland
| | - Sebastian Kiewnick
- Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants Federal Research Centre for cultivated Plants, Messeweg 11/12, 38104, Braunschweig, Germany.
| | - Etienne G J Danchin
- Université Côte d'Azur, IN RAE, CNRS, Institut Sophia Agrobiotech, Sophia Antipolis, France.
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20
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Varadarajan AR, Allan RN, Valentin JDP, Castañeda Ocampo OE, Somerville V, Pietsch F, Buhmann MT, West J, Skipp PJ, van der Mei HC, Ren Q, Schreiber F, Webb JS, Ahrens CH. An integrated model system to gain mechanistic insights into biofilm-associated antimicrobial resistance in Pseudomonas aeruginosa MPAO1. NPJ Biofilms Microbiomes 2020; 6:46. [PMID: 33127897 PMCID: PMC7603352 DOI: 10.1038/s41522-020-00154-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and biofilm-associated antibiotic resistance. Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and genes missed within existing assemblies by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq data sets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth and a screen with the Tn-mutant library in microtiter plates. The screen identified hitherto unknown genes involved in biofilm growth and antibiotic resistance. Experiments conducted with the flow chamber across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated the function of both known genes and genes identified in the Tn-mutant screens. Differential protein abundance data from planktonic cells versus biofilm confirmed the upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type VI secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance, and resistance evolution in biofilms.
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Affiliation(s)
- Adithi R Varadarajan
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland.
| | - Raymond N Allan
- School of Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, SO17 1BJ, UK
- School of Pharmacy, Faculty of Health and Life Sciences, De Montfort University, Leicester, LE1 9BH, UK
| | - Jules D P Valentin
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Olga E Castañeda Ocampo
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Vincent Somerville
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Franziska Pietsch
- Division of Biodeterioration and Reference Organisms, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Matthias T Buhmann
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Jonathan West
- Faculty of Medicine, University of Southampton, Southampton, SO17 1BJ, UK
- Centre for Hybrid Biodevices, University of Southampton, Southampton, SO17 1BJ, UK
| | - Paul J Skipp
- Centre for Proteomics Research, University of Southampton, Southampton, SO17 1BJ, UK
| | - Henny C van der Mei
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Frank Schreiber
- Division of Biodeterioration and Reference Organisms, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Jeremy S Webb
- School of Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Christian H Ahrens
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland.
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21
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Affiliation(s)
- Jürgen Bartel
- Department of Microbial Proteomics, Institute of Microbiology, University of Greifswald, D-17489 Greifswald, Germany
| | - Adithi R. Varadarajan
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Thomas Sura
- Department of Microbial Proteomics, Institute of Microbiology, University of Greifswald, D-17489 Greifswald, Germany
| | - Christian H. Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics and SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Sandra Maaß
- Department of Microbial Proteomics, Institute of Microbiology, University of Greifswald, D-17489 Greifswald, Germany
| | - Dörte Becher
- Department of Microbial Proteomics, Institute of Microbiology, University of Greifswald, D-17489 Greifswald, Germany
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22
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Lutz S, Thuerig B, Oberhaensli T, Mayerhofer J, Fuchs JG, Widmer F, Freimoser FM, Ahrens CH. Harnessing the Microbiomes of Suppressive Composts for Plant Protection: From Metagenomes to Beneficial Microorganisms and Reliable Diagnostics. Front Microbiol 2020; 11:1810. [PMID: 32849417 PMCID: PMC7406687 DOI: 10.3389/fmicb.2020.01810] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 07/09/2020] [Indexed: 01/20/2023] Open
Abstract
Soil-borne diseases cause significant yield losses worldwide, are difficult to treat and often only limited options for disease management are available. It has long been known that compost amendments, which are routinely applied in organic and integrated farming as a part of good agricultural practice to close nutrient cycles, can convey a protective effect. Yet, the targeted use of composts against soil-borne diseases is hampered by the unpredictability of the efficacy. Several studies have identified and/or isolated beneficial microorganisms (i.e., bacteria, oomycetes, and fungi) from disease suppressive composts capable of suppressing pathogens (e.g., Pythium and Fusarium) in various crops (e.g., tomato, lettuce, and cucumber), and some of them have been developed into commercial products. Yet, there is growing evidence that synthetic or complex microbial consortia can be more effective in controlling diseases than single strains, but the underlying molecular mechanisms are poorly understood. Currently, a major bottleneck concerns the lack of functional assays to identify the most potent beneficial microorganisms and/or key microbial consortia from complex soil and compost microbiomes, which can harbor tens of thousands of species. This focused review describes microorganisms, which have been isolated from, amended to or found to be abundant in disease-suppressive composts and for which a beneficial effect has been documented. We point out opportunities to increasingly harness compost microbiomes for plant protection through an integrated systems approach that combines the power of functional assays to isolate biocontrol and plant growth promoting strains and further prioritize them, with functional genomics approaches that have been successfully applied in other fields of microbiome research. These include detailed metagenomics studies (i.e., amplicon and shotgun sequencing) to achieve a better understanding of the complex system compost and to identify members of taxa enriched in suppressive composts. Whole-genome sequencing and complete assembly of key isolates and their subsequent functional profiling can elucidate the mechanisms of action of biocontrol strains. Integrating the benefits of these approaches will bring the long-term goals of employing microorganisms for a sustainable control of plant pathogens and developing reliable diagnostic assays to assess the suppressiveness of composts within reach.
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Affiliation(s)
- Stefanie Lutz
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Barbara Thuerig
- Research Institute of Organic Agriculture (FiBL), Department of Crop Sciences, Frick, Switzerland
| | - Thomas Oberhaensli
- Research Institute of Organic Agriculture (FiBL), Department of Crop Sciences, Frick, Switzerland
| | | | - Jacques G Fuchs
- Research Institute of Organic Agriculture (FiBL), Department of Crop Sciences, Frick, Switzerland
| | - Franco Widmer
- Agroscope, Research Group Molecular Ecology, Zurich, Switzerland
| | - Florian M Freimoser
- Agroscope, Research Group Phytopathology and Zoology in Fruit and Vegetable Production, Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
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23
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Reva ON, Larisa SA, Mwakilili AD, Tibuhwa D, Lyantagaye S, Chan WY, Lutz S, Ahrens CH, Vater J, Borriss R. Complete genome sequence and epigenetic profile of Bacillus velezensis UCMB5140 used for plant and crop protection in comparison with other plant-associated Bacillus strains. Appl Microbiol Biotechnol 2020; 104:7643-7656. [PMID: 32651600 DOI: 10.1007/s00253-020-10767-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/11/2020] [Accepted: 07/02/2020] [Indexed: 01/29/2023]
Abstract
The application of biocontrol biopesticides based on plant growth-promoting rhizobacteria (PGPR), particularly members of the genus Bacillus, is considered a promising perspective to make agricultural practices sustainable and ecologically safe. Recent advances in genome sequencing by third-generation sequencing technologies, e.g., Pacific Biosciences' Single Molecule Real-Time (PacBio SMRT) platform, have allowed researchers to gain deeper insights into the molecular and genetic mechanisms of PGPR activities, and to compare whole genome sequences and global patterns of epigenetic modifications. In the current work, this approach was used to sequence and compare four Bacillus strains that exhibited various PGPR activities including the strain UCMB5140, which is used in the commercial biopesticide Phytosubtil. Whole genome comparison and phylogenomic inference assigned the strain UCMB5140 to the species Bacillus velezensis. Strong biocontrol activities of this strain were confirmed in several bioassays. Several factors that affect the evolution of active PGPR B. velezensis strains were identified: (1) horizontal acquisition of novel non-ribosomal peptide synthetases (NRPS) and adhesion genes; (2) rearrangements of functional modules of NRPS genes leading to strain specific combinations of their encoded products; (3) gain and loss of methyltransferases that can cause global alterations in DNA methylation patterns, which eventually may affect gene expression and regulate transcription. Notably, we identified a horizontally transferred NRPS operon encoding an uncharacterized polypeptide antibiotic in B. velezensis UCMB5140. Other horizontally acquired genes comprised a possible adhesin and a methyltransferase, which may explain the strain-specific methylation pattern of the chromosomal DNA of UCMB5140. KEY POINTS: • Whole genome sequence of the active PGPR Bacillus velezensis UCMB5140. • Identification of genetic determinants responsible for PGPR activities. • Role of methyltransferases and epigenetic mechanisms in evolution of bacteria.
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Affiliation(s)
- Oleg N Reva
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hillcrest, Lynnwood Rd., Pretoria, South Africa.
| | - Safronova A Larisa
- Innovation and Technology Transfer Laboratory, DK Zabolotny Institute of Microbiology and Virology, 154 Zabolotnogo Str, Kyiv, 03143, Ukraine
| | - Aneth D Mwakilili
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania.,Plant Protection Department, Swedish University of Agricultural Sciences (SLU), Alnarp, Sweden
| | - Donatha Tibuhwa
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Sylvester Lyantagaye
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Wai Yin Chan
- Biotechnology Platform (BTP), Agricultural Research Council, Onderstepoort Veterinary Research Campus, Old Soutpan Rd, Onderstepoort, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.,Forestry and Agricultural Biotechnology Institute (FABI), DST-NRF Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria, Pretoria, South Africa
| | - Stefanie Lutz
- Agroscope, Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Müller-Thurgau-Str. 29, 8820, Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Müller-Thurgau-Str. 29, 8820, Wädenswil, Switzerland
| | | | - Rainer Borriss
- Institut für Biologie, Humboldt Universität Berlin, Berlin, Germany
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24
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Melior H, Maaß S, Li S, Förstner KU, Azarderakhsh S, Varadarajan AR, Stötzel M, Elhossary M, Barth-Weber S, Ahrens CH, Becher D, Evguenieva-Hackenberg E. The Leader Peptide peTrpL Forms Antibiotic-Containing Ribonucleoprotein Complexes for Posttranscriptional Regulation of Multiresistance Genes. mBio 2020; 11:e01027-20. [PMID: 32546623 PMCID: PMC7298713 DOI: 10.1128/mbio.01027-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 05/07/2020] [Indexed: 11/20/2022] Open
Abstract
Bacterial ribosome-dependent attenuators are widespread posttranscriptional regulators. They harbor small upstream open reading frames (uORFs) encoding leader peptides, for which no functions in trans are known yet. In the plant symbiont Sinorhizobium meliloti, the tryptophan biosynthesis gene trpE(G) is preceded by the uORF trpL and is regulated by transcription attenuation according to tryptophan availability. However, trpLE(G) transcription is initiated independently of the tryptophan level in S. meliloti, thereby ensuring a largely tryptophan-independent production of the leader peptide peTrpL. Here, we provide evidence for a tryptophan-independent role of peTrpL in trans We found that peTrpL increases the resistance toward tetracycline, erythromycin, chloramphenicol, and the flavonoid genistein, which are substrates of the major multidrug efflux pump SmeAB. Coimmunoprecipitation with a FLAG-peTrpL suggested smeR mRNA, which encodes the transcription repressor of smeABR, as a peptide target. Indeed, upon antibiotic exposure, smeR mRNA was destabilized and smeA stabilized in a peTrpL-dependent manner, showing that peTrpL acts in the differential regulation of smeABR Furthermore, smeR mRNA was coimmunoprecipitated with peTrpL in antibiotic-dependent ribonucleoprotein (ARNP) complexes, which, in addition, contained an antibiotic-induced antisense RNA complementary to smeRIn vitro ARNP reconstitution revealed that the above-mentioned antibiotics and genistein directly support complex formation. A specific region of the antisense RNA was identified as a seed region for ARNP assembly in vitro Altogether, our data show that peTrpL is involved in a mechanism for direct utilization of antimicrobial compounds in posttranscriptional regulation of multiresistance genes. Importantly, this role of peTrpL in resistance is conserved in other AlphaproteobacteriaIMPORTANCE Leader peptides encoded by transcription attenuators are widespread small proteins that are considered nonfunctional in trans We found that the leader peptide peTrpL of the soil-dwelling plant symbiont Sinorhizobium meliloti is required for differential, posttranscriptional regulation of a multidrug resistance operon upon antibiotic exposure. Multiresistance achieved by efflux of different antimicrobial compounds ensures survival and competitiveness in nature and is important from both evolutionary and medical points of view. We show that the leader peptide forms antibiotic- and flavonoid-dependent ribonucleoprotein complexes (ARNPs) for destabilization of smeR mRNA encoding the transcription repressor of the major multidrug resistance operon. The seed region for ARNP assembly was localized in an antisense RNA, whose transcription is induced by antimicrobial compounds. The discovery of ARNP complexes as new players in multiresistance regulation opens new perspectives in understanding bacterial physiology and evolution and potentially provides new targets for antibacterial control.
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Affiliation(s)
- Hendrik Melior
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | - Sandra Maaß
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Siqi Li
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | - Konrad U Förstner
- ZB MED-Information Centre for Life Sciences, University of Cologne, Cologne, Germany
| | - Saina Azarderakhsh
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | | | - Maximilian Stötzel
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | - Muhammad Elhossary
- ZB MED-Information Centre for Life Sciences, University of Cologne, Cologne, Germany
| | - Susanne Barth-Weber
- Institute of Microbiology and Molecular Biology, University of Giessen, Giessen, Germany
| | - Christian H Ahrens
- Agroscope & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
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25
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De Vrieze M, Varadarajan AR, Schneeberger K, Bailly A, Rohr RP, Ahrens CH, Weisskopf L. Linking Comparative Genomics of Nine Potato-Associated Pseudomonas Isolates With Their Differing Biocontrol Potential Against Late Blight. Front Microbiol 2020; 11:857. [PMID: 32425922 PMCID: PMC7204214 DOI: 10.3389/fmicb.2020.00857] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/09/2020] [Indexed: 01/22/2023] Open
Abstract
For plants, the advantages of associating with beneficial bacteria include plant growth promotion, reduction of abiotic and biotic stresses and enhanced protection against various pests and diseases. Beneficial bacteria rightly equipped for successful plant colonization and showing antagonistic activity toward plant pathogens seem to be actively recruited by plants. To gain more insights into the genetic determinants responsible for plant colonization and antagonistic activities, we first sequenced and de novo assembled the complete genomes of nine Pseudomonas strains that had exhibited varying antagonistic potential against the notorious oomycete Phytophthora infestans, placed them into the phylogenomic context of known Pseudomonas biocontrol strains and carried out a comparative genomic analysis to define core, accessory (i.e., genes found in two or more, but not all strains) and unique genes. Next, we assessed the colonizing abilities of these strains and used bioassays to characterize their inhibitory effects against different stages of P. infestans' lifecycle. The phenotype data were then correlated with genotype information, assessing over three hundred genes encoding known factors for plant colonization and antimicrobial activity as well as secondary metabolite biosynthesis clusters predicted by antiSMASH. All strains harbored genes required for successful plant colonization but also distinct arsenals of antimicrobial compounds. We identified genes coding for phenazine, hydrogen cyanide, 2-hexyl, 5-propyl resorcinol and pyrrolnitrin synthesis, as well as various siderophores, pyocins and type VI secretion systems. Additionally, the comparative genomic analysis revealed about a hundred accessory genes putatively involved in anti-Phytophthora activity, including a type II secretion system (T2SS), several peptidases and a toxin. Transcriptomic studies and mutagenesis are needed to further investigate the putative involvement of the novel candidate genes and to identify the various mechanisms involved in the inhibition of P. infestans by different Pseudomonas strains.
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Affiliation(s)
- Mout De Vrieze
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Adithi R. Varadarajan
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Kerstin Schneeberger
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Aurélien Bailly
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Rudolf P. Rohr
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Christian H. Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Laure Weisskopf
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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26
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Varadarajan AR, Goetze S, Pavlou MP, Grosboillot V, Shen Y, Loessner MJ, Ahrens CH, Wollscheid B. A Proteogenomic Resource Enabling Integrated Analysis of Listeria Genotype-Proteotype-Phenotype Relationships. J Proteome Res 2020; 19:1647-1662. [PMID: 32091902 DOI: 10.1021/acs.jproteome.9b00842] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Listeria monocytogenes is an opportunistic foodborne pathogen responsible for listeriosis, a potentially fatal foodborne disease. Many different Listeria strains and serotypes exist, but a proteogenomic resource that bridges the gap in our molecular understanding of the relationships between the Listeria genotypes and phenotypes via proteotypes is still missing. Here, we devised a next-generation proteogenomics strategy that enables the community to rapidly proteotype Listeria strains and relate this information back to the genotype. Based on sequencing and de novo assembly of the two most commonly used Listeria model strains, EGD-e and ScottA, we established two comprehensive Listeria proteogenomic databases. A genome comparison established core- and strain-specific genes potentially responsible for virulence differences. Next, we established a DIA/SWATH-based proteotyping strategy, including a new and robust sample preparation workflow, that enables the reproducible, sensitive, and relative quantitative measurement of Listeria proteotypes. This reusable and publicly available DIA/SWATH library covers 70% of open reading frames of Listeria and represents the most extensive spectral library for Listeria proteotype analysis to date. We used these two new resources to investigate the Listeria proteotype in states mimicking the upper gastrointestinal passage. Exposure of Listeria to bile salts at 37 °C, which simulates conditions encountered in the duodenum, showed significant proteotype perturbations including an increase of FlaA, the structural protein of flagella. Given that Listeria is known to lose its flagella above 30 °C, this was an unexpected finding. The formation of flagella, which might have implications on infectivity, was validated by parallel reaction monitoring and light and scanning electron microscopy. flaA transcript levels did not change significantly upon exposure to bile salts at 37 °C, suggesting regulation at the post-transcriptional level. Together, these analyses provide a comprehensive proteogenomic resource and toolbox for the Listeria community enabling the analysis of Listeria genotype-proteotype-phenotype relationships.
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Affiliation(s)
- Adithi R Varadarajan
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, 8820 Wädenswil, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Sandra Goetze
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland.,Institute of Translational Medicine (ITM), ETH Zürich, 8093 Zürich, Switzerland
| | - Maria P Pavlou
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Institute of Translational Medicine (ITM), ETH Zürich, 8093 Zürich, Switzerland
| | - Virginie Grosboillot
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Institute of Food, Nutrition and Health (IFNH), ETH Zürich, 8092 Zürich, Switzerland
| | - Yang Shen
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Institute of Food, Nutrition and Health (IFNH), ETH Zürich, 8092 Zürich, Switzerland
| | - Martin J Loessner
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Institute of Food, Nutrition and Health (IFNH), ETH Zürich, 8092 Zürich, Switzerland
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, 8820 Wädenswil, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Bernd Wollscheid
- Department of Health Sciences and Technology (D-HEST), ETH Zürich, 8092 Zürich, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland.,Institute of Translational Medicine (ITM), ETH Zürich, 8093 Zürich, Switzerland
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27
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Reva ON, Swanevelder DZH, Mwita LA, Mwakilili AD, Muzondiwa D, Joubert M, Chan WY, Lutz S, Ahrens CH, Avdeeva LV, Kharkhota MA, Tibuhwa D, Lyantagaye S, Vater J, Borriss R, Meijer J. Genetic, Epigenetic and Phenotypic Diversity of Four Bacillus velezensis Strains Used for Plant Protection or as Probiotics. Front Microbiol 2019; 10:2610. [PMID: 31803155 PMCID: PMC6873887 DOI: 10.3389/fmicb.2019.02610] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/28/2019] [Indexed: 12/11/2022] Open
Abstract
Bacillus velezensis strains are applied as ecologically safe biopesticides, plant growth promoting rhizobacteria (PGPR), and in veterinary probiotics. They are abundant in various environments including soil, plants, marine habitats, the intestinal micro-flora, etc. The mechanisms underlying this adaptive plasticity and bioactivity are not well understood, nor is it clear why several strains outperform other same species isolates by their bioactivities. The main objective of this work was to demonstrate versatility of bioactivities and lifestyle strategies of the selected B. velezensis strains suitable to serve as model organisms in future studies. Here, we performed a comparative study of newly sequenced genomes of four B. velezensis isolates with distinct phenotypes and isolation origin, which were assessed by RNA sequencing under the effect of root exudate stimuli and profiled by epigenetic modifications of chromosomal DNA. Among the selected strains, UCMB5044 is an oligotrophic PGPR strain adapted to nutrient poor desert soils. UCMB5113 and At1 are endophytes that colonize plants and require nutrient rich media. In contrast, the probiotic strain, UCMB5007, is a copiotroph, which shows no propensity to colonize plants. PacBio and Illumina sequencing approaches were used to generate complete genome assemblies, tracing epigenetic modifications, and determine gene expression profiles. All sequence data was deposited at NCBI. The strains, UCMB5113 and At1, show 99% sequence identity and similar phenotypes despite being isolated from geographically distant regions. UCMB5007 and UCMB5044 represent another group of organisms with almost identical genomes but dissimilar phenotypes and plant colonization propensity. The two plant associated strains, UCMB5044 and UCMB5113, share 398 genes putatively associated with root colonization, which are activated by exposure to maize root exudates. In contrast, UCMB5007 did not respond to root exudate stimuli. It was hypothesized that alterations in the global methylation pattern and some other epigenetic modifications enable adaptation of strains to different habitats and therefore may be of importance in terms of the biotechnological applicability of these bacteria. Contrary, the ability to grow on root exudates as a sole source of nutrients or a strong antagonism against phytopathogens showed by the strains in vitro cannot be considered as good predictors of PGPR activities.
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Affiliation(s)
- Oleg N Reva
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | | | - Liberata A Mwita
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.,Department of Pharmaceutical Microbiology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Aneth David Mwakilili
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania.,Department of Plant Protection, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Dillon Muzondiwa
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Monique Joubert
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Wai Yin Chan
- Biotechnology Platform, Agricultural Research Council, Pretoria, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.,Forestry and Agricultural Biotechnology Institute, DST-NRF Centre of Excellence in Tree Health Biotechnology, University of Pretoria, Pretoria, South Africa
| | - Stefanie Lutz
- Agroscope, Molecular Diagnostics, Genomics and Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics and Bioinformatics and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Lylia V Avdeeva
- Department of Antibiotics, D.K. Zabolotny Institute of Microbiology and Virology, Kyiv, Ukraine
| | - Maksim A Kharkhota
- Department of Antibiotics, D.K. Zabolotny Institute of Microbiology and Virology, Kyiv, Ukraine
| | - Donatha Tibuhwa
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Sylvester Lyantagaye
- Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Tanzania
| | | | - Rainer Borriss
- Institut für Biologie, Humboldt Universität zu Berlin, Berlin, Germany
| | - Johan Meijer
- Department of Plant Biology, Linnéan Center for Plant Biology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
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28
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Schmid M, Frei D, Patrignani A, Schlapbach R, Frey JE, Remus-Emsermann MNP, Ahrens CH. Pushing the limits of de novo genome assembly for complex prokaryotic genomes harboring very long, near identical repeats. Nucleic Acids Res 2019; 46:8953-8965. [PMID: 30137508 PMCID: PMC6158609 DOI: 10.1093/nar/gky726] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/15/2018] [Indexed: 12/16/2022] Open
Abstract
Generating a complete, de novo genome assembly for prokaryotes is often considered a solved problem. However, we here show that Pseudomonas koreensis P19E3 harbors multiple, near identical repeat pairs up to 70 kilobase pairs in length, which contained several genes that may confer fitness advantages to the strain. Its complex genome, which also included a variable shufflon region, could not be de novo assembled with long reads produced by Pacific Biosciences’ technology, but required very long reads from Oxford Nanopore Technologies. Importantly, a repeat analysis, whose results we release for over 9600 prokaryotes, indicated that very complex bacterial genomes represent a general phenomenon beyond Pseudomonas. Roughly 10% of 9331 complete bacterial and a handful of 293 complete archaeal genomes represented this ‘dark matter’ for de novo genome assembly of prokaryotes. Several of these ‘dark matter’ genome assemblies contained repeats far beyond the resolution of the sequencing technology employed and likely contain errors, other genomes were closed employing labor-intense steps like cosmid libraries, primer walking or optical mapping. Using very long sequencing reads in combination with assembly algorithms capable of resolving long, near identical repeats will bring most prokaryotic genomes within reach of fast and complete de novo genome assembly.
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Affiliation(s)
- Michael Schmid
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil CH-8820, Switzerland.,SIB Swiss Institute of Bioinformatics, Wädenswil CH-8820, Switzerland
| | - Daniel Frei
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil CH-8820, Switzerland
| | - Andrea Patrignani
- Functional Genomics Center Zurich, University of Zurich & ETH Zurich, Zurich CH-8057, Switzerland
| | - Ralph Schlapbach
- Functional Genomics Center Zurich, University of Zurich & ETH Zurich, Zurich CH-8057, Switzerland
| | - Jürg E Frey
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil CH-8820, Switzerland
| | - Mitja N P Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.,Biomolecular Interaction Centre, University of Canterbury, Christchurch, 8140, New Zealand
| | - Christian H Ahrens
- Agroscope, Molecular Diagnostics, Genomics & Bioinformatics, Wädenswil CH-8820, Switzerland.,SIB Swiss Institute of Bioinformatics, Wädenswil CH-8820, Switzerland
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29
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Somerville V, Lutz S, Schmid M, Frei D, Moser A, Irmler S, Frey JE, Ahrens CH. Long-read based de novo assembly of low-complexity metagenome samples results in finished genomes and reveals insights into strain diversity and an active phage system. BMC Microbiol 2019; 19:143. [PMID: 31238873 PMCID: PMC6593500 DOI: 10.1186/s12866-019-1500-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/31/2019] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Complete and contiguous genome assemblies greatly improve the quality of subsequent systems-wide functional profiling studies and the ability to gain novel biological insights. While a de novo genome assembly of an isolated bacterial strain is in most cases straightforward, more informative data about co-existing bacteria as well as synergistic and antagonistic effects can be obtained from a direct analysis of microbial communities. However, the complexity of metagenomic samples represents a major challenge. While third generation sequencing technologies have been suggested to enable finished metagenome-assembled genomes, to our knowledge, the complete genome assembly of all dominant strains in a microbiome sample has not been demonstrated. Natural whey starter cultures (NWCs) are used in cheese production and represent low-complexity microbiomes. Previous studies of Swiss Gruyère and selected Italian hard cheeses, mostly based on amplicon metagenomics, concurred that three species generally pre-dominate: Streptococcus thermophilus, Lactobacillus helveticus and Lactobacillus delbrueckii. RESULTS Two NWCs from Swiss Gruyère producers were subjected to whole metagenome shotgun sequencing using the Pacific Biosciences Sequel and Illumina MiSeq platforms. In addition, longer Oxford Nanopore Technologies MinION reads had to be generated for one to resolve repeat regions. Thereby, we achieved the complete assembly of all dominant bacterial genomes from these low-complexity NWCs, which was corroborated by a 16S rRNA amplicon survey. Moreover, two distinct L. helveticus strains were successfully co-assembled from the same sample. Besides bacterial chromosomes, we could also assemble several bacterial plasmids and phages and a corresponding prophage. Biologically relevant insights were uncovered by linking the plasmids and phages to their respective host genomes using DNA methylation motifs on the plasmids and by matching prokaryotic CRISPR spacers with the corresponding protospacers on the phages. These results could only be achieved by employing long-read sequencing data able to span intragenomic as well as intergenomic repeats. CONCLUSIONS Here, we demonstrate the feasibility of complete de novo genome assembly of all dominant strains from low-complexity NWCs based on whole metagenomics shotgun sequencing data. This allowed to gain novel biological insights and is a fundamental basis for subsequent systems-wide omics analyses, functional profiling and phenotype to genotype analysis of specific microbial communities.
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Affiliation(s)
- Vincent Somerville
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
- SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Stefanie Lutz
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
- SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Michael Schmid
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
- SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Daniel Frei
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Aline Moser
- Agroscope, Research Group Biochemistry of Milk and Microorganisms, CH-3003 Bern, Switzerland
| | - Stefan Irmler
- Agroscope, Research Group Biochemistry of Milk and Microorganisms, CH-3003 Bern, Switzerland
| | - Jürg E. Frey
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Christian H. Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics & Bioinformatics, Schloss 1, CH-8820 Wädenswil, Switzerland
- SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
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30
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Gore-Lloyd D, Sumann I, Brachmann AO, Schneeberger K, Ortiz-Merino RA, Moreno-Beltrán M, Schläfli M, Kirner P, Santos Kron A, Rueda-Mejia MP, Somerville V, Wolfe KH, Piel J, Ahrens CH, Henk D, Freimoser FM. Snf2 controls pulcherriminic acid biosynthesis and antifungal activity of the biocontrol yeast Metschnikowia pulcherrima. Mol Microbiol 2019; 112:317-332. [PMID: 31081214 PMCID: PMC6851878 DOI: 10.1111/mmi.14272] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2019] [Indexed: 12/14/2022]
Abstract
Metschnikowia pulcherrima synthesises the pigment pulcherrimin, from cyclodileucine (cyclo(Leu-Leu)) as a precursor, and exhibits strong antifungal activity against notorious plant pathogenic fungi. This yeast therefore has great potential for biocontrol applications against fungal diseases; particularly in the phyllosphere where this species is frequently found. To elucidate the molecular basis of the antifungal activity of M. pulcherrima, we compared a wild-type strain with a spontaneously occurring, pigmentless, weakly antagonistic mutant derivative. Whole genome sequencing of the wild-type and mutant strains identified a point mutation that creates a premature stop codon in the transcriptional regulator gene SNF2 in the mutant. Complementation of the mutant strain with the wild-type SNF2 gene restored pigmentation and recovered the strong antifungal activity. Mass spectrometry (UPLC HR HESI-MS) proved the presence of the pulcherrimin precursors cyclo(Leu-Leu) and pulcherriminic acid and identified new precursor and degradation products of pulcherriminic acid and/or pulcherrimin. All of these compounds were identified in the wild-type and complemented strain, but were undetectable in the pigmentless snf2 mutant strain. These results thus identify Snf2 as a regulator of antifungal activity and pulcherriminic acid biosynthesis in M. pulcherrima and provide a starting point for deciphering the molecular functions underlying the antagonistic activity of this yeast.
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Affiliation(s)
- Deborah Gore-Lloyd
- Department of Biology & Biochemistry, University of Bath, Bath, BA2 7AY, UK
| | - Inés Sumann
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Alexander O Brachmann
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, 8093, Zürich, Switzerland
| | - Kerstin Schneeberger
- Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | | | | | - Michael Schläfli
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Pascal Kirner
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Amanda Santos Kron
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Maria Paula Rueda-Mejia
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Vincent Somerville
- Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Kenneth H Wolfe
- Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Jörn Piel
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, 8093, Zürich, Switzerland
| | - Christian H Ahrens
- Competence Division Method Development and Analytics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland.,SIB, Swiss Institute of Bioinformatics, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
| | - Daniel Henk
- Department of Biology & Biochemistry, University of Bath, Bath, BA2 7AY, UK
| | - Florian M Freimoser
- Agroscope, Research Division Plant Protection, Müller-Thurgau-Strasse 29, 8820, Wädenswil, Switzerland
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31
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Fernández N, Cabrera JJ, Varadarajan AR, Lutz S, Ledermann R, Roschitzki B, Eberl L, Bedmar EJ, Fischer HM, Pessi G, Ahrens CH, Mesa S. An Integrated Systems Approach Unveils New Aspects of Microoxia-Mediated Regulation in Bradyrhizobium diazoefficiens. Front Microbiol 2019; 10:924. [PMID: 31134003 PMCID: PMC6515984 DOI: 10.3389/fmicb.2019.00924] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/11/2019] [Indexed: 01/31/2023] Open
Abstract
The adaptation of rhizobia from the free-living state in soil to the endosymbiotic state comprises several physiological changes in order to cope with the extremely low oxygen availability (microoxia) within nodules. To uncover cellular functions required for bacterial adaptation to microoxia directly at the protein level, we applied a systems biology approach on the key rhizobial model and soybean endosymbiont Bradyrhizobium diazoefficiens USDA 110 (formerly B. japonicum USDA 110). As a first step, the complete genome of B. diazoefficiens 110spc4, the model strain used in most prior functional genomics studies, was sequenced revealing a deletion of a ~202 kb fragment harboring 223 genes and several additional differences, compared to strain USDA 110. Importantly, the deletion strain showed no significantly different phenotype during symbiosis with several host plants, reinforcing the value of previous OMICS studies. We next performed shotgun proteomics and detected 2,900 and 2,826 proteins in oxically and microoxically grown cells, respectively, largely expanding our knowledge about the inventory of rhizobial proteins expressed in microoxia. A set of 62 proteins was significantly induced under microoxic conditions, including the two nitrogenase subunits NifDK, the nitrogenase reductase NifH, and several subunits of the high-affinity terminal cbb3 oxidase (FixNOQP) required for bacterial respiration inside nodules. Integration with the previously defined microoxia-induced transcriptome uncovered a set of 639 genes or proteins uniquely expressed in microoxia. Finally, besides providing proteogenomic evidence for novelties, we also identified proteins with a regulation similar to that of FixK2: transcript levels of these protein-coding genes were significantly induced, while the corresponding protein abundance remained unchanged or was down-regulated. This suggested that, apart from fixK2, additional B. diazoefficiens genes might be under microoxia-specific post-transcriptional control. This hypothesis was indeed confirmed for several targets (HemA, HemB, and ClpA) by immunoblot analysis.
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Affiliation(s)
- Noemí Fernández
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Juan J Cabrera
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Adithi R Varadarajan
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics and Swiss Institute of Bioinformatics, Wädenswil, Switzerland.,Department of Health Sciences and Technology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Stefanie Lutz
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics and Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | | | - Bernd Roschitzki
- Functional Genomics Center Zurich, ETH & UZH Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Eulogio J Bedmar
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | | | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics and Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Socorro Mesa
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
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Huntscha S, Stravs MA, Bühlmann A, Ahrens CH, Frey JE, Pomati F, Hollender J, Buerge IJ, Balmer ME, Poiger T. Seasonal Dynamics of Glyphosate and AMPA in Lake Greifensee: Rapid Microbial Degradation in the Epilimnion During Summer. Environ Sci Technol 2018; 52:4641-4649. [PMID: 29584408 DOI: 10.1021/acs.est.8b00314] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Occurrence and fate of glyphosate, a widely used herbicide, and its main metabolite AMPA was investigated in Lake Greifensee, Switzerland. Monthly vertical concentration profiles in the lake showed an increase of glyphosate concentrations in the epilimnion from 15 ng/L in March to 145 ng/L in July, followed by a sharp decline to <5 ng/L in August. A similar pattern was observed for AMPA. Concentrations of glyphosate and AMPA in the two main tributaries generally were much higher than in the lake. Simulations using a numerical lake model indicated that a substantial amount of glyphosate and AMPA dissipated in the epilimnion, mainly in July and August, with half-lives of only ≈2-4 days which is ≫100 times faster than in the preceding months. Fast dissipation coincided with high water temperatures and phytoplankton densities, and low phosphate concentrations. This indicates that glyphosate might have been used as an alternative phosphorus source by bacterio- and phytoplankton. Metagenomic analysis of lake water revealed the presence of organisms known to be capable of degrading glyphosate and AMPA.
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Affiliation(s)
| | - Michael A Stravs
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf , Switzerland
- ETH Zurich , Institute of Biogeochemistry and Pollutant Dynamics , 8092 Zürich , Switzerland
| | | | - Christian H Ahrens
- Agroscope , Schloss 1 , 8820 Wädenswil , Switzerland
- Swiss Institute of Bioinformatics (SIB) , Schloss 1 , 8820 Wädenswil , Switzerland
| | - Jürg E Frey
- Agroscope , Schloss 1 , 8820 Wädenswil , Switzerland
| | - Francesco Pomati
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf , Switzerland
- ETH Zurich, Institute for Integrative Biology , 8092 Zürich , Switzerland
| | - Juliane Hollender
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf , Switzerland
- ETH Zurich , Institute of Biogeochemistry and Pollutant Dynamics , 8092 Zürich , Switzerland
| | | | | | - Thomas Poiger
- Agroscope , Schloss 1 , 8820 Wädenswil , Switzerland
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33
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Lardi M, Liu Y, Giudice G, Ahrens CH, Zamboni N, Pessi G. Metabolomics and Transcriptomics Identify Multiple Downstream Targets of Paraburkholderia phymatum σ 54 During Symbiosis with Phaseolus vulgaris. Int J Mol Sci 2018; 19:ijms19041049. [PMID: 29614780 PMCID: PMC5979394 DOI: 10.3390/ijms19041049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/28/2018] [Accepted: 03/28/2018] [Indexed: 12/20/2022] Open
Abstract
RpoN (or σ54) is the key sigma factor for the regulation of transcription of nitrogen fixation genes in diazotrophic bacteria, which include α- and β-rhizobia. Our previous studies showed that an rpoN mutant of the β-rhizobial strain Paraburkholderia phymatum STM815T formed root nodules on Phaseolus vulgaris cv. Negro jamapa, which were unable to reduce atmospheric nitrogen into ammonia. In an effort to further characterize the RpoN regulon of P. phymatum, transcriptomics was combined with a powerful metabolomics approach. The metabolome of P. vulgaris root nodules infected by a P. phymatumrpoN Fix− mutant revealed statistically significant metabolic changes compared to wild-type Fix+ nodules, including reduced amounts of chorismate and elevated levels of flavonoids. A transcriptome analysis on Fix− and Fix+ nodules—combined with a search for RpoN binding sequences in promoter regions of regulated genes—confirmed the expected control of σ54 on nitrogen fixation genes in nodules. The transcriptomic data also allowed us to identify additional target genes, whose differential expression was able to explain the observed metabolite changes in numerous cases. Moreover, the genes encoding the two-component regulatory system NtrBC were downregulated in root nodules induced by the rpoN mutant, and contained a putative RpoN binding motif in their promoter region, suggesting direct regulation. The construction and characterization of an ntrB mutant strain revealed impaired nitrogen assimilation in free-living conditions, as well as a noticeable symbiotic phenotype, as fewer but heavier nodules were formed on P. vulgaris roots.
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Affiliation(s)
- Martina Lardi
- Department of Plant and Microbial Biology, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Yilei Liu
- Department of Plant and Microbial Biology, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Gaetano Giudice
- Department of Plant and Microbial Biology, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), CH-8820 Wädenswil, Switzerland.
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, CH-8057 Zurich, Switzerland.
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34
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Zengerer V, Schmid M, Bieri M, Müller DC, Remus-Emsermann MNP, Ahrens CH, Pelludat C. Pseudomonas orientalis F9: A Potent Antagonist against Phytopathogens with Phytotoxic Effect in the Apple Flower. Front Microbiol 2018; 9:145. [PMID: 29479340 PMCID: PMC5811506 DOI: 10.3389/fmicb.2018.00145] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/23/2018] [Indexed: 12/16/2022] Open
Abstract
In light of public concerns over the use of pesticides and antibiotics in plant protection and the subsequent selection for spread of resistant bacteria in the environment, it is inevitable to broaden our knowledge about viable alternatives, such as natural antagonists and their mode of action. The genus Pseudomonas is known for its metabolic versatility and genetic plasticity, encompassing pathogens as well as antagonists. We characterized strain Pseudomonas orientalis F9, an isolate from apple flowers in a Swiss orchard, and determined its antagonistic activity against several phytopathogenic bacteria, in particular Erwinia amylovora, the causal agent of fire blight. P. orientalis F9 displayed antagonistic activity against a broad suite of phytopathogenic bacteria in the in vitro tests. The promising results from this analysis led to an ex vivo assay with E. amylovora CFBP1430Rif and P. orientalis F9 infected detached apple flowers. F9 diminished the fire blight pathogen in the flowers but also revealed phytotoxic traits. The experimental results were discussed in light of the complete genome sequence of F9, which revealed the strain to carry phenazine genes. Phenazines are known to contribute to antagonistic activity of bacterial strains against soil pathogens. When tested in the cress assay with Pythium ultimum as pathogen, F9 showed results comparable to the known antagonist P. protegens CHA0.
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Affiliation(s)
| | - Michael Schmid
- Competence Division Methods Development, Analytics and SIB Swiss Institute of Bioinformatics, Agroscope, Zurich, Switzerland
| | - Marco Bieri
- Plant Protection Research Division, Agroscope, Zurich, Switzerland
| | - Denise C. Müller
- Plant Protection Research Division, Agroscope, Zurich, Switzerland
| | - Mitja N. P. Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Christian H. Ahrens
- Competence Division Methods Development, Analytics and SIB Swiss Institute of Bioinformatics, Agroscope, Zurich, Switzerland
| | - Cosima Pelludat
- Plant Protection Research Division, Agroscope, Zurich, Switzerland
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Schmid M, Muri J, Melidis D, Varadarajan AR, Somerville V, Wicki A, Moser A, Bourqui M, Wenzel C, Eugster-Meier E, Frey JE, Irmler S, Ahrens CH. Comparative Genomics of Completely Sequenced Lactobacillus helveticus Genomes Provides Insights into Strain-Specific Genes and Resolves Metagenomics Data Down to the Strain Level. Front Microbiol 2018; 9:63. [PMID: 29441050 PMCID: PMC5797582 DOI: 10.3389/fmicb.2018.00063] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/10/2018] [Indexed: 11/20/2022] Open
Abstract
Although complete genome sequences hold particular value for an accurate description of core genomes, the identification of strain-specific genes, and as the optimal basis for functional genomics studies, they are still largely underrepresented in public repositories. Based on an assessment of the genome assembly complexity for all lactobacilli, we used Pacific Biosciences' long read technology to sequence and de novo assemble the genomes of three Lactobacillus helveticus starter strains, raising the number of completely sequenced strains to 12. The first comparative genomics study for L. helveticus—to our knowledge—identified a core genome of 988 genes and sets of unique, strain-specific genes ranging from about 30 to more than 200 genes. Importantly, the comparison of MiSeq- and PacBio-based assemblies uncovered that not only accessory but also core genes can be missed in incomplete genome assemblies based on short reads. Analysis of the three genomes revealed that a large number of pseudogenes were enriched for functional Gene Ontology categories such as amino acid transmembrane transport and carbohydrate metabolism, which is in line with a reductive genome evolution in the rich natural habitat of L. helveticus. Notably, the functional Clusters of Orthologous Groups of proteins categories “cell wall/membrane biogenesis” and “defense mechanisms” were found to be enriched among the strain-specific genes. A genome mining effort uncovered examples where an experimentally observed phenotype could be linked to the underlying genotype, such as for cell envelope proteinase PrtH3 of strain FAM8627. Another possible link identified for peptidoglycan hydrolases will require further experiments. Of note, strain FAM22155 did not harbor a CRISPR/Cas system; its loss was also observed in other L. helveticus strains and lactobacillus species, thus questioning the value of the CRISPR/Cas system for diagnostic purposes. Importantly, the complete genome sequences proved to be very useful for the analysis of natural whey starter cultures with metagenomics, as a larger percentage of the sequenced reads of these complex mixtures could be unambiguously assigned down to the strain level.
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Affiliation(s)
- Michael Schmid
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Jonathan Muri
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland
| | - Damianos Melidis
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland
| | - Adithi R Varadarajan
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Vincent Somerville
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Adrian Wicki
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland
| | - Aline Moser
- Agroscope, Research Group Biochemistry of Milk and Microorganisms, Bern, Switzerland
| | - Marc Bourqui
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Claudia Wenzel
- Agroscope, Research Group Biochemistry of Milk and Microorganisms, Bern, Switzerland
| | - Elisabeth Eugster-Meier
- School of Agricultural, Forest and Food Sciences HAFL, Bern University of Applied Sciences, Zollikofen, Switzerland
| | - Juerg E Frey
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland
| | - Stefan Irmler
- Agroscope, Research Group Biochemistry of Milk and Microorganisms, Bern, Switzerland
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics, Wädenswil, Switzerland.,Swiss Institute of Bioinformatics, Wädenswil, Switzerland
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36
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Omasits U, Varadarajan AR, Schmid M, Goetze S, Melidis D, Bourqui M, Nikolayeva O, Québatte M, Patrignani A, Dehio C, Frey JE, Robinson MD, Wollscheid B, Ahrens CH. An integrative strategy to identify the entire protein coding potential of prokaryotic genomes by proteogenomics. Genome Res 2017; 27:2083-2095. [PMID: 29141959 PMCID: PMC5741054 DOI: 10.1101/gr.218255.116] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 10/25/2017] [Indexed: 12/18/2022]
Abstract
Accurate annotation of all protein-coding sequences (CDSs) is an essential prerequisite to fully exploit the rapidly growing repertoire of completely sequenced prokaryotic genomes. However, large discrepancies among the number of CDSs annotated by different resources, missed functional short open reading frames (sORFs), and overprediction of spurious ORFs represent serious limitations. Our strategy toward accurate and complete genome annotation consolidates CDSs from multiple reference annotation resources, ab initio gene prediction algorithms and in silico ORFs (a modified six-frame translation considering alternative start codons) in an integrated proteogenomics database (iPtgxDB) that covers the entire protein-coding potential of a prokaryotic genome. By extending the PeptideClassifier concept of unambiguous peptides for prokaryotes, close to 95% of the identifiable peptides imply one distinct protein, largely simplifying downstream analysis. Searching a comprehensive Bartonella henselae proteomics data set against such an iPtgxDB allowed us to unambiguously identify novel ORFs uniquely predicted by each resource, including lipoproteins, differentially expressed and membrane-localized proteins, novel start sites and wrongly annotated pseudogenes. Most novelties were confirmed by targeted, parallel reaction monitoring mass spectrometry, including unique ORFs and single amino acid variations (SAAVs) identified in a re-sequenced laboratory strain that are not present in its reference genome. We demonstrate the general applicability of our strategy for genomes with varying GC content and distinct taxonomic origin. We release iPtgxDBs for B. henselae, Bradyrhizobium diazoefficiens and Escherichia coli and the software to generate both proteogenomics search databases and integrated annotation files that can be viewed in a genome browser for any prokaryote.
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Affiliation(s)
- Ulrich Omasits
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Adithi R Varadarajan
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland.,Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, CH-8093 Zurich, Switzerland
| | - Michael Schmid
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Sandra Goetze
- Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, CH-8093 Zurich, Switzerland
| | - Damianos Melidis
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Marc Bourqui
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Olga Nikolayeva
- Institute for Molecular Life Sciences & SIB Swiss Institute of Bioinformatics, University of Zurich, CH-8057 Zurich, Switzerland
| | | | - Andrea Patrignani
- Functional Genomics Center Zurich, ETH & UZH Zurich, CH-8057 Zurich, Switzerland
| | | | - Juerg E Frey
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
| | - Mark D Robinson
- Institute for Molecular Life Sciences & SIB Swiss Institute of Bioinformatics, University of Zurich, CH-8057 Zurich, Switzerland
| | - Bernd Wollscheid
- Department of Health Sciences and Technology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology Zurich, CH-8093 Zurich, Switzerland
| | - Christian H Ahrens
- Agroscope, Research Group Molecular Diagnostics, Genomics and Bioinformatics & SIB Swiss Institute of Bioinformatics, CH-8820 Wädenswil, Switzerland
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Montes Vidal D, von Rymon-Lipinski AL, Ravella S, Groenhagen U, Herrmann J, Zaburannyi N, Zarbin PHG, Varadarajan AR, Ahrens CH, Weisskopf L, Müller R, Schulz S. Langkettige Alkylcyanide, beispiellose flüchtige Verbindungen aus Pseudomonas
- und Micromonospora
-Bakterien. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Diogo Montes Vidal
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Deutschland
- Laboratório de Semioquímicos; Departamento de Química - UFPR; Curitiba - PR Brasilien
| | | | - Srinivasa Ravella
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Deutschland
| | - Ulrike Groenhagen
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Deutschland
| | - Jennifer Herrmann
- Abteilung Mikrobielle Naturstoffe; Helmholtz-Institut für Pharmazeutische Forschung Saarland; Helmholtz-Zentrum für Infektionsforschung; Universität des Saarlandes; Saarbrücken Deutschland
| | - Nestor Zaburannyi
- Abteilung Mikrobielle Naturstoffe; Helmholtz-Institut für Pharmazeutische Forschung Saarland; Helmholtz-Zentrum für Infektionsforschung; Universität des Saarlandes; Saarbrücken Deutschland
| | - Paulo H. G. Zarbin
- Laboratório de Semioquímicos; Departamento de Química - UFPR; Curitiba - PR Brasilien
| | | | | | - Laure Weisskopf
- Institut für Weinbau und Önologie; Fachhochschule Westschweiz; Schweiz
- Agroscope; Schweiz
| | - Rolf Müller
- Abteilung Mikrobielle Naturstoffe; Helmholtz-Institut für Pharmazeutische Forschung Saarland; Helmholtz-Zentrum für Infektionsforschung; Universität des Saarlandes; Saarbrücken Deutschland
| | - Stefan Schulz
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Deutschland
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Montes Vidal D, von Rymon-Lipinski AL, Ravella S, Groenhagen U, Herrmann J, Zaburannyi N, Zarbin PHG, Varadarajan AR, Ahrens CH, Weisskopf L, Müller R, Schulz S. Long-Chain Alkyl Cyanides: Unprecedented Volatile Compounds Released by Pseudomonas
and Micromonospora
Bacteria. Angew Chem Int Ed Engl 2017; 56:4342-4346. [DOI: 10.1002/anie.201611940] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 01/18/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Diogo Montes Vidal
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Germany
- Laboratório de Semioquímicos; Departamento de Química-UFPR; Curitiba PR Brazil
| | | | - Srinivasa Ravella
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Ulrike Groenhagen
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Germany
| | - Jennifer Herrmann
- Microbial Natural Products; Helmholtz Institute for Pharmaceutical Research Saarland; Helmholtz Centre for Infection Research; Saarland University; Saarbrücken Germany
| | - Nestor Zaburannyi
- Microbial Natural Products; Helmholtz Institute for Pharmaceutical Research Saarland; Helmholtz Centre for Infection Research; Saarland University; Saarbrücken Germany
| | - Paulo H. G. Zarbin
- Laboratório de Semioquímicos; Departamento de Química-UFPR; Curitiba PR Brazil
| | | | | | - Laure Weisskopf
- Institute for Viticulture and Oenology; University of Applied Sciences and Arts Western Switzerland; Switzerland
- Agroscope; Switzerland
| | - Rolf Müller
- Microbial Natural Products; Helmholtz Institute for Pharmaceutical Research Saarland; Helmholtz Centre for Infection Research; Saarland University; Saarbrücken Germany
| | - Stefan Schulz
- Institut für Organische Chemie; TU Braunschweig; Hagenring 30 38106 Braunschweig Germany
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Hilber-Bodmer M, Schmid M, Ahrens CH, Freimoser FM. Competition assays and physiological experiments of soil and phyllosphere yeasts identify Candida subhashii as a novel antagonist of filamentous fungi. BMC Microbiol 2017; 17:4. [PMID: 28056814 PMCID: PMC5216558 DOI: 10.1186/s12866-016-0908-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 12/06/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While recent advances in next generation sequencing technologies have enabled researchers to readily identify countless microbial species in soil, rhizosphere, and phyllosphere microbiomes, the biological functions of the majority of these species are unknown. Functional studies are therefore urgently needed in order to characterize the plethora of microorganisms that are being identified and to point out species that may be used for biotechnology or plant protection. Here, we used a dual culture assay and growth analyses to characterise yeasts (40 different isolates) and their antagonistic effect on 16 filamentous fungi; comprising plant pathogens, antagonists, and saprophytes. RESULTS Overall, this competition screen of 640 pairwise combinations revealed a broad range of outcomes, ranging from small stimulatory effects of some yeasts up to a growth inhibition of more than 80% by individual species. On average, yeasts isolated from soil suppressed filamentous fungi more strongly than phyllosphere yeasts and the antagonistic activity was a species-/isolate-specific property and not dependent on the filamentous fungus a yeast was interacting with. The isolates with the strongest antagonistic activity were Metschnikowia pulcherrima, Hanseniaspora sp., Cyberlindnera sargentensis, Aureobasidium pullulans, Candida subhashii, and Pichia kluyveri. Among these, the soil yeasts (C. sargentensis, A. pullulans, C. subhashii) assimilated and/or oxidized more di-, tri- and tetrasaccharides and organic acids than yeasts from the phyllosphere. Only the two yeasts C. subhashii and M. pulcherrima were able to grow with N-acetyl-glucosamine as carbon source. CONCLUSIONS The competition assays and physiological experiments described here identified known antagonists that have been implicated in the biological control of plant pathogenic fungi in the past, but also little characterised species such as C. subhashii. Overall, soil yeasts were more antagonistic and metabolically versatile than yeasts from the phyllosphere. Noteworthy was the strong antagonistic activity of the soil yeast C. subhashii, which had so far only been described from a clinical sample and not been studied with respect to biocontrol. Based on binary competition assays and growth analyses (e.g., on different carbon sources, growth in root exudates), C. subhashii was identified as a competitive and antagonistic soil yeast with potential as a novel biocontrol agent against plant pathogenic fungi.
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Affiliation(s)
- Maja Hilber-Bodmer
- Agroscope, Institute for Plant Production Sciences IPS, Schloss 1, P.B., 8820, Wädenswil, Switzerland
| | - Michael Schmid
- Agroscope, Institute for Plant Production Sciences IPS, Schloss 1, P.B., 8820, Wädenswil, Switzerland.,SIB, Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Institute for Plant Production Sciences IPS, Schloss 1, P.B., 8820, Wädenswil, Switzerland.,SIB, Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Florian M Freimoser
- Agroscope, Institute for Plant Production Sciences IPS, Schloss 1, P.B., 8820, Wädenswil, Switzerland.
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Remus-Emsermann MN, Schmid M, Gekenidis MT, Pelludat C, Frey JE, Ahrens CH, Drissner D. Complete genome sequence of Pseudomonas citronellolis P3B5, a candidate for microbial phyllo-remediation of hydrocarbon-contaminated sites. Stand Genomic Sci 2016; 11:75. [PMID: 28300228 PMCID: PMC5037603 DOI: 10.1186/s40793-016-0190-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 08/31/2016] [Indexed: 12/04/2022] Open
Abstract
Pseudomonas citronellolis is a Gram negative, motile gammaproteobacterium belonging to the order Pseudomonadales and the family Pseudomonadaceae. We isolated strain P3B5 from the phyllosphere of basil plants (Ocimum basilicum L.). Here we describe the physiology of this microorganism, its full genome sequence, and detailed annotation. The 6.95 Mbp genome contains 6071 predicted protein coding sequences and 96 RNA coding sequences. P. citronellolis has been the subject of many studies including the investigation of long-chain aliphatic compounds and terpene degradation. Plant leaves are covered by long-chain aliphates making up a waxy layer that is associated with the leaf cuticle. In addition, basil leaves are known to contain high amounts of terpenoid substances, hinting to a potential nutrient niche that might be exploited by P. citronellolis. Furthermore, the isolated strain exhibited resistance to several antibiotics. To evaluate the potential of this strain as source of transferable antibiotic resistance genes on raw consumed herbs we therefore investigated if those resistances are encoded on mobile genetic elements. The availability of the genome will be helpful for comparative genomics of the phylogenetically broad pseudomonads, in particular with the sequence of the P. citronellolis type strain PRJDB205 not yet publicly available. The genome is discussed with respect to a phyllosphere related lifestyle, aliphate and terpenoid degradation, and antibiotic resistance.
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Affiliation(s)
| | - Michael Schmid
- Agroscope, Institute for Plant Production Sciences IPS, Wädenswil, Switzerland
- Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Maria-Theresia Gekenidis
- Agroscope, Institute for Food Sciences IFS, Wädenswil, Switzerland
- ETH Zurich, Institute of Food, Nutrition and Health, Zurich, Switzerland
| | - Cosima Pelludat
- Agroscope, Institute for Plant Production Sciences IPS, Wädenswil, Switzerland
| | - Jürg E. Frey
- Agroscope, Institute for Plant Production Sciences IPS, Wädenswil, Switzerland
| | - Christian H. Ahrens
- Agroscope, Institute for Plant Production Sciences IPS, Wädenswil, Switzerland
- Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - David Drissner
- Agroscope, Institute for Food Sciences IFS, Wädenswil, Switzerland
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Marti R, Muniesa M, Schmid M, Ahrens CH, Naskova J, Hummerjohann J. Short communication: Heat-resistant Escherichia coli as potential persistent reservoir of extended-spectrum β-lactamases and Shiga toxin-encoding phages in dairy. J Dairy Sci 2016; 99:8622-8632. [PMID: 27568050 DOI: 10.3168/jds.2016-11076] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 07/13/2016] [Indexed: 12/11/2022]
Abstract
Here we report the isolation of heat-resistant Escherichia coli from raw milk cheeses. Detection of the heat-resistance markers clpK and orfI by PCR was followed by phenotypical confirmation of increased heat-resistance. These strains were Shiga toxin-negative and, although several were found to be multidrug resistant, no plasmids encoding extended-spectrum β-lactamases (ESBL) were found in any of the isolates. The aim of this study was to assess the potential of these strains to acquire ESBL plasmids and a modified Shiga toxin-encoding phage. Only 4 ESBL-encoding, heat-sensitive E. coli strains were isolated from 1,251 dairy samples (2/455 raw milk and 2/796 raw milk cheese samples). One incompatibility group FII plasmid (CTX-M-14, 79.0 kb) and 3 incompatibility group I1 plasmids (CTX-M-15, 95.2, 96.1, and 97.8 kb) were fully sequenced and de novo assembled. All 4 plasmids are readily transferred to heat-resistant E. coli isolates in plate matings (9.7×10-5 to 3.7×10-1 exconjugants per recipient) and, to a lesser extent, in milk (up to 7.4×10-5 exconjugants per recipient). Importantly, the plasmids are stably maintained during passaging in liquid media without antimicrobial pressure. The heat-resistant isolate FAM21805 was also shown to be capable of acting as donor of all 4 ESBL plasmids. In addition, 3 of 11 tested ESBL exconjugants of heat-resistant strains were lysogenized by the modified Shiga toxin-encoding phage 933W ∆stx::gfp::cat. The higher fraction of heat-resistant E. coli (93 of 256 isolates) compared with the estimated 2% previously predicted based on genomic prevalence of heat resistance genes seems to indicate a selection advantage in the raw milk cheese production environment. The combination of 2 factors may lead to said advantage: increased survival during thermization of raw milk (heating to subpasteurization temperatures) and increased survival rates during cheese ripening. Should these strains acquire ESBL-encoding plasmids, Shiga toxin-encoding phages, or both, these genetic elements would profit from the selection advantage of their host and become more abundant in this particular environment, which in turn could lead to an increased threat to consumers of raw milk products.
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Affiliation(s)
- Roger Marti
- Agroscope, Institute for Food Sciences IFS, Schwarzenburgstrasse 161, CH-3003 Bern, Switzerland
| | - Maite Muniesa
- Department of Microbiology, University of Barcelona, 08007 Barcelona, Spain
| | - Michael Schmid
- Agroscope, Institute for Plant Production Sciences IPS and Swiss Institute of Bioinformatics, Schloss 1, 8820 Wädenswil, Switzerland
| | - Christian H Ahrens
- Agroscope, Institute for Plant Production Sciences IPS and Swiss Institute of Bioinformatics, Schloss 1, 8820 Wädenswil, Switzerland
| | - Javorka Naskova
- Agroscope, Institute for Food Sciences IFS, Schwarzenburgstrasse 161, CH-3003 Bern, Switzerland
| | - Jörg Hummerjohann
- Agroscope, Institute for Food Sciences IFS, Schwarzenburgstrasse 161, CH-3003 Bern, Switzerland.
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Lardi M, Murset V, Fischer HM, Mesa S, Ahrens CH, Zamboni N, Pessi G. Metabolomic Profiling of Bradyrhizobium diazoefficiens-Induced Root Nodules Reveals Both Host Plant-Specific and Developmental Signatures. Int J Mol Sci 2016; 17:E815. [PMID: 27240350 PMCID: PMC4926349 DOI: 10.3390/ijms17060815] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/13/2016] [Accepted: 05/19/2016] [Indexed: 01/17/2023] Open
Abstract
Bradyrhizobium diazoefficiens is a nitrogen-fixing endosymbiont, which can grow inside root-nodule cells of the agriculturally important soybean and other host plants. Our previous studies described B. diazoefficiens host-specific global expression changes occurring during legume infection at the transcript and protein level. In order to further characterize nodule metabolism, we here determine by flow injection-time-of-flight mass spectrometry analysis the metabolome of (i) nodules and roots from four different B. diazoefficiens host plants; (ii) soybean nodules harvested at different time points during nodule development; and (iii) soybean nodules infected by two strains mutated in key genes for nitrogen fixation, respectively. Ribose (soybean), tartaric acid (mungbean), hydroxybutanoyloxybutanoate (siratro) and catechol (cowpea) were among the metabolites found to be specifically elevated in one of the respective host plants. While the level of C4-dicarboxylic acids decreased during soybean nodule development, we observed an accumulation of trehalose-phosphate at 21 days post infection (dpi). Moreover, nodules from non-nitrogen-fixing bacteroids (nifA and nifH mutants) showed specific metabolic alterations; these were also supported by independent transcriptomics data. The alterations included signs of nitrogen limitation in both mutants, and an increased level of a phytoalexin in nodules induced by the nifA mutant, suggesting that the tissue of these nodules exhibits defense and stress reactions.
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Affiliation(s)
- Martina Lardi
- Department of Plant and Microbial Biology, University of Zürich, CH-8057 Zürich, Switzerland.
| | - Valérie Murset
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zürich, Switzerland.
| | - Hans-Martin Fischer
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zürich, Switzerland.
| | - Socorro Mesa
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), E-18080 Granada, Spain.
| | - Christian H Ahrens
- Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), CH-8820 Wädenswil, Switzerland.
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, ETH Zürich, CH-8093 Zürich, Switzerland.
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zürich, CH-8057 Zürich, Switzerland.
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Čuklina J, Hahn J, Imakaev M, Omasits U, Förstner KU, Ljubimov N, Goebel M, Pessi G, Fischer HM, Ahrens CH, Gelfand MS, Evguenieva-Hackenberg E. Genome-wide transcription start site mapping of Bradyrhizobium japonicum grown free-living or in symbiosis - a rich resource to identify new transcripts, proteins and to study gene regulation. BMC Genomics 2016; 17:302. [PMID: 27107716 PMCID: PMC4842269 DOI: 10.1186/s12864-016-2602-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 03/25/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Differential RNA-sequencing (dRNA-seq) is indispensable for determination of primary transcriptomes. However, using dRNA-seq data to map transcriptional start sites (TSSs) and promoters genome-wide is a bioinformatics challenge. We performed dRNA-seq of Bradyrhizobium japonicum USDA 110, the nitrogen-fixing symbiont of soybean, and developed algorithms to map TSSs and promoters. RESULTS A specialized machine learning procedure for TSS recognition allowed us to map 15,923 TSSs: 14,360 in free-living bacteria, 4329 in symbiosis with soybean and 2766 in both conditions. Further, we provide proteomic evidence for 4090 proteins, among them 107 proteins corresponding to new genes and 178 proteins with N-termini different from the existing annotation (72 and 109 of them with TSS support, respectively). Guided by proteomics evidence, previously identified TSSs and TSSs experimentally validated here, we assign a score threshold to flag 14 % of the mapped TSSs as a class of lower confidence. However, this class of lower confidence contains valid TSSs of low-abundant transcripts. Moreover, we developed a de novo algorithm to identify promoter motifs upstream of mapped TSSs, which is publicly available, and found motifs mainly used in symbiosis (similar to RpoN-dependent promoters) or under both conditions (similar to RpoD-dependent promoters). Mapped TSSs and putative promoters, proteomic evidence and updated gene annotation were combined into an annotation file. CONCLUSIONS The genome-wide TSS and promoter maps along with the extended genome annotation of B. japonicum represent a valuable resource for future systems biology studies and for detailed analyses of individual non-coding transcripts and ORFs. Our data will also provide new insights into bacterial gene regulation during the agriculturally important symbiosis between rhizobia and legumes.
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Affiliation(s)
- Jelena Čuklina
- />AA Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoi Karetny pereulok 19, Moscow, 127051 Russia
- />Moscow Institute of Physics and Technology, Institutskiy pereulok 9, Dolgoprudnyy, Moscow region 141700 Russia
- />Present Address: Institute of Molecular Systems Biology, ETH Zürich, Auguste-Piccard Hof 1, CH-8093 Zürich, Switzerland
| | - Julia Hahn
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Maxim Imakaev
- />Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 USA
| | - Ulrich Omasits
- />Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Konrad U. Förstner
- />Core Unit Systems Medicine, University of Würzburg, Josef-Schneider-Str. 2 Bau D15, D-97080 Würzburg, Germany
| | - Nikolay Ljubimov
- />Lomonosov Moscow State University, Faculty of Computational Mathematics and Cybernetics, Leninskie Gory, 2-nd educational building, Moscow, 119991 Russia
| | - Melanie Goebel
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Gabriella Pessi
- />ETH, Institute of Microbiology, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland
- />Present Address: Department of Plant and Microbial Biology University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Hans-Martin Fischer
- />ETH, Institute of Microbiology, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland
| | - Christian H. Ahrens
- />Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Mikhail S. Gelfand
- />AA Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoi Karetny pereulok 19, Moscow, 127051 Russia
- />Department of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Vorobievy Gory 73-1, Moscow, 119991 Russia
| | - Elena Evguenieva-Hackenberg
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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Turnbull L, Toyofuku M, Hynen AL, Kurosawa M, Pessi G, Petty NK, Osvath SR, Cárcamo-Oyarce G, Gloag ES, Shimoni R, Omasits U, Ito S, Yap X, Monahan LG, Cavaliere R, Ahrens CH, Charles IG, Nomura N, Eberl L, Whitchurch CB. Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms. Nat Commun 2016; 7:11220. [PMID: 27075392 PMCID: PMC4834629 DOI: 10.1038/ncomms11220] [Citation(s) in RCA: 372] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 03/02/2016] [Indexed: 02/07/2023] Open
Abstract
Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content in Pseudomonas aeruginosa biofilms. Super-resolution microscopy reveals that explosive cell lysis also produces shattered membrane fragments that rapidly form MVs. A prophage endolysin encoded within the R- and F-pyocin gene cluster is essential for explosive cell lysis. Endolysin-deficient mutants are defective in MV production and biofilm development, consistent with a crucial role in the biogenesis of MVs and liberation of extracellular DNA and other biofilm matrix components. Our findings reveal that explosive cell lysis, mediated through the activity of a cryptic prophage endolysin, acts as a mechanism for the production of bacterial MVs.
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Affiliation(s)
- Lynne Turnbull
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Masanori Toyofuku
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.,Department of Plant and Microbial Biology, University of Zurich, Zürich 8008, Switzerland
| | - Amelia L Hynen
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Masaharu Kurosawa
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zürich 8008, Switzerland
| | - Nicola K Petty
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Sarah R Osvath
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Gerardo Cárcamo-Oyarce
- Department of Plant and Microbial Biology, University of Zurich, Zürich 8008, Switzerland
| | - Erin S Gloag
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Raz Shimoni
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Ulrich Omasits
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zürich 8093, Switzerland
| | - Satoshi Ito
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Xinhui Yap
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Leigh G Monahan
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Rosalia Cavaliere
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Christian H Ahrens
- Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics, &Swiss Institute of Bioinformatics (SIB), Wädenswil 8820, Switzerland
| | - Ian G Charles
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Nobuhiko Nomura
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zürich 8008, Switzerland
| | - Cynthia B Whitchurch
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
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45
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Urfer M, Bogdanovic J, Lo Monte F, Moehle K, Zerbe K, Omasits U, Ahrens CH, Pessi G, Eberl L, Robinson JA. A Peptidomimetic Antibiotic Targets Outer Membrane Proteins and Disrupts Selectively the Outer Membrane in Escherichia coli. J Biol Chem 2015; 291:1921-1932. [PMID: 26627837 DOI: 10.1074/jbc.m115.691725] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 01/05/2023] Open
Abstract
Increasing antibacterial resistance presents a major challenge in antibiotic discovery. One attractive target in Gram-negative bacteria is the unique asymmetric outer membrane (OM), which acts as a permeability barrier that protects the cell from external stresses, such as the presence of antibiotics. We describe a novel β-hairpin macrocyclic peptide JB-95 with potent antimicrobial activity against Escherichia coli. This peptide exhibits no cellular lytic activity, but electron microscopy and fluorescence studies reveal an ability to selectively disrupt the OM but not the inner membrane of E. coli. The selective targeting of the OM probably occurs through interactions of JB-95 with selected β-barrel OM proteins, including BamA and LptD as shown by photolabeling experiments. Membrane proteomic studies reveal rapid depletion of many β-barrel OM proteins from JB-95-treated E. coli, consistent with induction of a membrane stress response and/or direct inhibition of the Bam folding machine. The results suggest that lethal disruption of the OM by JB-95 occurs through a novel mechanism of action at key interaction sites within clusters of β-barrel proteins in the OM. These findings open new avenues for developing antibiotics that specifically target β-barrel proteins and the integrity of the Gram-negative OM.
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Affiliation(s)
- Matthias Urfer
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich
| | - Jasmina Bogdanovic
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich
| | - Fabio Lo Monte
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich
| | - Kerstin Moehle
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich
| | - Katja Zerbe
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich
| | - Ulrich Omasits
- the Institute of Molecular Systems Biology, ETH Zurich, Auguste-Piccard Hof 1, 8093 Zurich, Switzerland
| | - Christian H Ahrens
- the Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics, and Bioinformatics and the Swiss Institute of Bioinformatics, Agroscope, Schloss 1, 8820 Wädenswil, Switzerland, and
| | - Gabriella Pessi
- the Department of Microbiology, Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Leo Eberl
- the Department of Microbiology, Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - John A Robinson
- From the Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich,.
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46
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De Vrieze M, Pandey P, Bucheli TD, Varadarajan AR, Ahrens CH, Weisskopf L, Bailly A. Volatile Organic Compounds from Native Potato-associated Pseudomonas as Potential Anti-oomycete Agents. Front Microbiol 2015; 6:1295. [PMID: 26635763 PMCID: PMC4655239 DOI: 10.3389/fmicb.2015.01295] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/06/2015] [Indexed: 01/06/2023] Open
Abstract
The plant kingdom represents a prominent biodiversity island for microbes that associate with the below- or aboveground organs of vegetal species. Both the root and the leaf represent interfaces where dynamic biological interactions influence plant life. Beside well-studied communication strategies based on soluble compounds and protein effectors, bacteria were recently shown to interact both with host plants and other microbial species through the emissions of volatile organic compounds (VOCs). Focusing on the potato late blight-causing agent Phytophthora infestans, this work addresses the potential role of the bacterial volatilome in suppressing plant diseases. In a previous study, we isolated and identified a large collection of strains with anti-Phytophthora potential from both the phyllosphere and the rhizosphere of potato. Here we report the characterization and quantification of their emissions of biogenic volatiles, comparing 16 Pseudomonas strains differing in (i) origin of isolation (phyllosphere vs. rhizosphere), (ii) in vitro inhibition of P. infestans growth and sporulation behavior, and (iii) protective effects against late blight on potato leaf disks. We systematically tested the pharmacological inhibitory activity of core and strain-specific single compounds against P. infestans mycelial growth and sporangial behavior in order to identify key effective candidate molecules present in the complex natural VOCs blends. We envisage the plant bacterial microbiome as a reservoir for functional VOCs and establish the basis for finding the primary enzymatic toolset that enables the production of active components of the volatile bouquet in plant-associated bacteria. Comprehension of these functional interspecies interactions will open perspectives for the sustainable control of plant diseases in forthcoming agriculture.
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Affiliation(s)
- Mout De Vrieze
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
| | - Piyush Pandey
- Department of Microbiology, Assam UniversitySilchar, India
| | | | - Adithi R. Varadarajan
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- Swiss Institute of BioinformaticsWädenswil, Switzerland
| | - Christian H. Ahrens
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- Swiss Institute of BioinformaticsWädenswil, Switzerland
| | - Laure Weisskopf
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- CHANGINS, Viticulture and Oenology, University of Applied Sciences and Arts Western SwitzerlandNyon, Switzerland
| | - Aurélien Bailly
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Microbiology, Institute of Plant Biology, University of ZurichZurich, Switzerland
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47
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Qeli E, Omasits U, Goetze S, Stekhoven DJ, Frey JE, Basler K, Wollscheid B, Brunner E, Ahrens CH. Improved prediction of peptide detectability for targeted proteomics using a rank-based algorithm and organism-specific data. J Proteomics 2014; 108:269-83. [DOI: 10.1016/j.jprot.2014.05.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 05/14/2014] [Accepted: 05/17/2014] [Indexed: 02/07/2023]
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48
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Stekhoven DJ, Omasits U, Quebatte M, Dehio C, Ahrens CH. Proteome-wide identification of predominant subcellular protein localizations in a bacterial model organism. J Proteomics 2014; 99:123-37. [PMID: 24486812 DOI: 10.1016/j.jprot.2014.01.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 01/12/2014] [Accepted: 01/15/2014] [Indexed: 01/04/2023]
Abstract
UNLABELLED Proteomics data provide unique insights into biological systems, including the predominant subcellular localization (SCL) of proteins, which can reveal important clues about their functions. Here we analyzed data of a complete prokaryotic proteome expressed under two conditions mimicking interaction of the emerging pathogen Bartonella henselae with its mammalian host. Normalized spectral count data from cytoplasmic, total membrane, inner and outer membrane fractions allowed us to identify the predominant SCL for 82% of the identified proteins. The spectral count proportion of total membrane versus cytoplasmic fractions indicated the propensity of cytoplasmic proteins to co-fractionate with the inner membrane, and enabled us to distinguish cytoplasmic, peripheral inner membrane and bona fide inner membrane proteins. Principal component analysis and k-nearest neighbor classification training on selected marker proteins or predominantly localized proteins, allowed us to determine an extensive catalog of at least 74 expressed outer membrane proteins, and to extend the SCL assignment to 94% of the identified proteins, including 18% where in silico methods gave no prediction. Suitable experimental proteomics data combined with straightforward computational approaches can thus identify the predominant SCL on a proteome-wide scale. Finally, we present a conceptual approach to identify proteins potentially changing their SCL in a condition-dependent fashion. BIOLOGICAL SIGNIFICANCE The work presented here describes the first prokaryotic proteome-wide subcellular localization (SCL) dataset for the emerging pathogen B. henselae (Bhen). The study indicates that suitable subcellular fractionation experiments combined with straight-forward computational analysis approaches assessing the proportion of spectral counts observed in different subcellular fractions are powerful for determining the predominant SCL of a large percentage of the experimentally observed proteins. This includes numerous cases where in silico prediction methods do not provide any prediction. Avoiding a treatment with harsh conditions, cytoplasmic proteins tend to co-fractionate with proteins of the inner membrane fraction, indicative of close functional interactions. The spectral count proportion (SCP) of total membrane versus cytoplasmic fractions allowed us to obtain a good indication about the relative proximity of individual protein complex members to the inner membrane. Using principal component analysis and k-nearest neighbor approaches, we were able to extend the percentage of proteins with a predominant experimental localization to over 90% of all expressed proteins and identified a set of at least 74 outer membrane (OM) proteins. In general, OM proteins represent a rich source of candidates for the development of urgently needed new therapeutics in combat of resurgence of infectious disease and multi-drug resistant bacteria. Finally, by comparing the data from two infection biology relevant conditions, we conceptually explore methods to identify and visualize potential candidates that may partially change their SCL in these different conditions. The data are made available to researchers as a SCL compendium for Bhen and as an assistance in further improving in silico SCL prediction algorithms.
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Affiliation(s)
- Daniel J Stekhoven
- Quantitative Model Organism Proteomics (Q-MOP), Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| | - Ulrich Omasits
- Quantitative Model Organism Proteomics (Q-MOP), Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Institute of Molecular Systems Biology, ETH Zurich, Auguste-Piccard-Hof 1, 8093 Zurich, Switzerland
| | - Maxime Quebatte
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Christoph Dehio
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Christian H Ahrens
- Quantitative Model Organism Proteomics (Q-MOP), Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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Carlier AL, Omasits U, Ahrens CH, Eberl L. Proteomics analysis of Psychotria leaf nodule symbiosis: improved genome annotation and metabolic predictions. Mol Plant Microbe Interact 2013; 26:1325-1333. [PMID: 23902262 DOI: 10.1094/mpmi-05-13-0152-r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Several plant species of the genus Psychotria (Rubiaceae) harbor Burkholderia sp. bacteria within specialized leaf nodules. The bacteria are transmitted vertically between plant generations and have not yet been cultured outside of their host. This symbiosis is considered to be obligatory because plants devoid of symbionts fail to develop into mature individuals. The genome of 'Candidatus Burkholderia kirkii' has been sequenced recently and has revealed evidence of reductive genome evolution, as shown by the proliferation of insertion sequences and the presence of numerous pseudogenes. We employed shotgun proteomics to investigate the expression of 'Ca. B. kirkii' proteins in the leaf nodule. Drawing from this dataset and refined comparative genomics analyses, we designed a new pseudogene prediction algorithm and improved the genome annotation. We also found conclusive evidence that nodule bacteria allocate vast resources to synthesis of secondary metabolites, possibly of the C7N aminocyclitol family. Expression of a putative 2-epi-5-valiolone synthase, a key enzyme of the C7N aminocyclitol synthesis, is high in the nodule population but downregulated in bacteria residing in the shoot apex, suggesting that production of secondary metabolites is particularly important in the leaf nodule.
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50
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Omasits U, Ahrens CH, Müller S, Wollscheid B. Protter: interactive protein feature visualization and integration with experimental proteomic data. ACTA ACUST UNITED AC 2013; 30:884-6. [PMID: 24162465 DOI: 10.1093/bioinformatics/btt607] [Citation(s) in RCA: 838] [Impact Index Per Article: 76.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
SUMMARY The ability to integrate and visualize experimental proteomic evidence in the context of rich protein feature annotations represents an unmet need of the proteomics community. Here we present Protter, a web-based tool that supports interactive protein data analysis and hypothesis generation by visualizing both annotated sequence features and experimental proteomic data in the context of protein topology. Protter supports numerous proteomic file formats and automatically integrates a variety of reference protein annotation sources, which can be readily extended via modular plug-ins. A built-in export function produces publication-quality customized protein illustrations, also for large datasets. Visualizations of surfaceome datasets show the specific utility of Protter for the integrated visual analysis of membrane proteins and peptide selection for targeted proteomics. AVAILABILITY AND IMPLEMENTATION The Protter web application is available at http://wlab.ethz.ch/protter. Source code and installation instructions are available at http://ulo.github.io/Protter/. CONTACT wbernd@ethz.ch SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Ulrich Omasits
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, 8093 Zürich and Institute of Molecular Life Sciences, University of Zürich, 8057 Zürich, Switzerland
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