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Lam YC, Hamchand R, Mucci NC, Kauffman SJ, Dudkina N, Reagle EV, Casanova-Torres ÁM, DeCuyper J, Chen H, Song D, Thomas MG, Palm NW, Goodrich-Blair H, Crawford JM. The Xenorhabdus nematophila LrhA transcriptional regulator modulates production of γ-keto- N-acyl amides with inhibitory activity against mutualistic host nematode egg hatching. Appl Environ Microbiol 2024:e0052824. [PMID: 38916293 DOI: 10.1128/aem.00528-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 06/01/2024] [Indexed: 06/26/2024] Open
Abstract
Xenorhabdus nematophila is a symbiotic Gammaproteobacterium that produces diverse natural products that facilitate mutualistic and pathogenic interactions in their nematode and insect hosts, respectively. The interplay between X. nematophila secondary metabolism and symbiosis stage is tuned by various global regulators. An example of such a regulator is the LysR-type protein transcription factor LrhA, which regulates amino acid metabolism and is necessary for virulence in insects and normal nematode progeny production. Here, we utilized comparative metabolomics and molecular networking to identify small molecule factors regulated by LrhA and characterized a rare γ-ketoacid (GKA) and two new N-acyl amides, GKA-Arg (1) and GKA-Pro (2) which harbor a γ-keto acyl appendage. A lrhA null mutant produced elevated levels of compound 1 and reduced levels of compound 2 relative to wild type. N-acyl amides 1 and 2 were shown to be selective agonists for the human G-protein-coupled receptors (GPCRs) C3AR1 and CHRM2, respectively. The CHRM2 agonist 2 deleteriously affected the hatch rate and length of Steinernema nematodes. This work further highlights the utility of exploiting regulators of host-bacteria interactions for the identification of the bioactive small molecule signals that they control. IMPORTANCE Xenorhabdus bacteria are of interest due to their symbiotic relationship with Steinernema nematodes and their ability to produce a variety of natural bioactive compounds. Despite their importance, the regulatory hierarchy connecting specific natural products and their regulators is poorly understood. In this study, comparative metabolomic profiling was utilized to identify the secondary metabolites modulated by the X. nematophila global regulator LrhA. This analysis led to the discovery of three metabolites, including an N-acyl amide that inhibited the egg hatching rate and length of Steinernema carpocapsae nematodes. These findings support the notion that X. nematophila LrhA influences the symbiosis between X. nematophila and S. carpocapsae through N-acyl amide signaling. A deeper understanding of the regulatory hierarchy of these natural products could contribute to a better comprehension of the symbiotic relationship between X. nematophila and S. carpocapsae.
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Affiliation(s)
- Yick Chong Lam
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut, USA
| | - Randy Hamchand
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut, USA
| | - Nicholas C Mucci
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Sarah J Kauffman
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Natavan Dudkina
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut, USA
| | - Emily V Reagle
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Jessica DeCuyper
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Haiwei Chen
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Deguang Song
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Michael G Thomas
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Noah W Palm
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Heidi Goodrich-Blair
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M Crawford
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
- Institute of Biomolecular Design & Discovery, Yale University, West Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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2
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Han Y, Zhang S, Wang Y, Gao J, Han J, Yan Z, Ta Y, Wang Y. Enhancing the yield of Xenocoumacin 1 in Xenorhabdus nematophila YL001 by optimizing the fermentation process. Sci Rep 2024; 14:13506. [PMID: 38866882 PMCID: PMC11169479 DOI: 10.1038/s41598-024-63794-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 06/03/2024] [Indexed: 06/14/2024] Open
Abstract
Xenocoumacin 1 (Xcn 1), antibiotic discovered from secondary metabolites of Xenorhabdus nematophila, had the potential to develop into a new pesticide due to its excellent activity against bacteria, oomycetes and fungi. However, the current low yield of Xcn1 limits its development and utilization. To improve the yield of Xcn1, response surface methodology was used to determine the optimal composition of fermentation medium and one factor at a time approach was utilized to optimize the fermentation process. The optimal medium composed of in g/L: proteose peptone 20.8; maltose 12.74; K2HPO4 3.77. The optimal fermentation conditions were that 25 °C, initial pH 7.0, inoculum size 10%, culture medium 75 mL in a 250 mL shake flask with an agitation rate of 150 rpm for 48 h. Xenorhabdus nematophila YL001 was produced the highest Xcn1 yield (173.99 mg/L) when arginine was added to the broth with 3 mmol/L at the 12th h. Compared with Tryptic Soy Broth medium, the optimized fermentation process resulted in a 243.38% increase in Xcn1 production. The obtained results confirmed that optimizing fermentation technology led to an increase in Xcn1 yield. This work would be helpful for efficient Xcn1 production and lay a foundation for its industrial production.
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Affiliation(s)
- Yunfei Han
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Shujing Zhang
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, 58 People's Avenue, Haikou, 570228, Hainan, China
| | - Yang Wang
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jiangtao Gao
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jinhua Han
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Zhiqiang Yan
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Yongquan Ta
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Yonghong Wang
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
- Shaanxi Research Center of Biopesticide Engineering & Technology, College of Plant Protection, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
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3
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Smith LM, Hampton HG, Yevstigneyeva MS, Mahler M, Paquet ZM, Fineran PC. CRISPR-Cas immunity is repressed by the LysR-type transcriptional regulator PigU. Nucleic Acids Res 2024; 52:755-768. [PMID: 38059344 PMCID: PMC10810281 DOI: 10.1093/nar/gkad1165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/17/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023] Open
Abstract
Bacteria protect themselves from infection by bacteriophages (phages) using different defence systems, such as CRISPR-Cas. Although CRISPR-Cas provides phage resistance, fitness costs are incurred, such as through autoimmunity. CRISPR-Cas regulation can optimise defence and minimise these costs. We recently developed a genome-wide functional genomics approach (SorTn-seq) for high-throughput discovery of regulators of bacterial gene expression. Here, we applied SorTn-seq to identify loci influencing expression of the two type III-A Serratia CRISPR arrays. Multiple genes affected CRISPR expression, including those involved in outer membrane and lipopolysaccharide synthesis. By comparing loci affecting type III CRISPR arrays and cas operon expression, we identified PigU (LrhA) as a repressor that co-ordinately controls both arrays and cas genes. By repressing type III-A CRISPR-Cas expression, PigU shuts off CRISPR-Cas interference against plasmids and phages. PigU also represses interference and CRISPR adaptation by the type I-F system, which is also present in Serratia. RNA sequencing demonstrated that PigU is a global regulator that controls secondary metabolite production and motility, in addition to CRISPR-Cas immunity. Increased PigU also resulted in elevated expression of three Serratia prophages, indicating their likely induction upon sensing PigU-induced cellular changes. In summary, PigU is a major regulator of CRISPR-Cas immunity in Serratia.
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Affiliation(s)
- Leah M Smith
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Hannah G Hampton
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Mariya S Yevstigneyeva
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Marina Mahler
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Zacharie S M Paquet
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Jin G, Hrithik MTH, Lee DH, Kim IH, Jung JS, Bode HB, Kim Y. Manipulation of GameXPeptide synthetase gene expression by a promoter exchange alters the virulence of an entomopathogenic bacterium, Photorhabdus temperata temperata, by modulating insect immune responses. Front Microbiol 2023; 14:1271764. [PMID: 38173677 PMCID: PMC10764021 DOI: 10.3389/fmicb.2023.1271764] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/23/2023] [Indexed: 01/05/2024] Open
Abstract
An entomopathogenic bacterium, Photorhabdus temperata subsp. temperata, is mutualistic to its host nematode, Heterorhabditis megidis. The infective juvenile nematodes enter target insects through natural openings and release the symbiotic bacteria into the insect hemocoel. The released bacteria suppress the insect immune responses and cause septicemia through their secondary metabolites. GameXPeptide (GXP) is one of the common secondary metabolites of most Photorhabdus species and is produced by the catalytic activity of a specific non-ribosomal peptide synthetase called GxpS encoded by the gxpS gene. This study confirmed gxpS to be encoded in the P. temperata temperata genome and analyzed its expression during bacterial growth. LC-MS/MS analysis of the bacterial culture broth contained at least four different GXPs (GXP-A to GXP-D), in which GXP-A was the most abundant. To investigate GXP synthesis following gxpS expression, the gxpS promoter of P. temperata temperata was replaced with an inducible arabinose promoter by homologous recombination. The gxpS transcript levels in the mutant were altered by the addition of l-arabinose. Without the inducer, the gxpS transcript level was significantly lower compared to the wild type and produced significantly lower amounts of the four GXPs. The addition of the inducer to the mutant significantly increased gxpS expression and produced significantly higher levels of the four GXPs compared to the wild type. The metabolite extracts obtained from wild-type and mutant bacteria showed differential immunosuppressive activities according to their GXP contents against the cellular and humoral immune responses of a lepidopteran insect, Spodoptera exigua. Interestingly, the gxpS-mutant bacteria showed less insecticidal activity compared to the wild type, whereas the addition of GXP to the mutant significantly restored insecticidal activity. These results suggest that the gxpS gene encoded in P. temperata temperata is responsible for the production of at least four different GXPs, which play crucial roles in bacterial virulence.
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Affiliation(s)
- Gahyeon Jin
- Department of Plant Medicals, Andong National University, Andong, Republic of Korea
| | | | - Dong-Hee Lee
- Industry Academy Cooperation Foundation, Andong National University, Andong, Republic of Korea
| | - Il-Hwan Kim
- Korea Research Institute of Standards and Science, Daejeon, Republic of Korea
| | - Ji-Seon Jung
- Korea Research Institute of Standards and Science, Daejeon, Republic of Korea
| | - Helge B. Bode
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Molecular Biotechnology, Department of Biosciences, Goethe Universität Frankfurt, Frankfurt, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Phillips Universität Marburg, Marburg, Germany
- Department of Chemistry, Phillips Universität Marburg, Marburg, Germany
- Senckenberg Gesellschaft für Naturforschung, Frankfurt, Germany
| | - Yonggyun Kim
- Department of Plant Medicals, Andong National University, Andong, Republic of Korea
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5
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Liu F, Chen Z, Zhang S, Wu K, Bei C, Wang C, Chao Y. In vivo RNA interactome profiling reveals 3'UTR-processed small RNA targeting a central regulatory hub. Nat Commun 2023; 14:8106. [PMID: 38062076 PMCID: PMC10703908 DOI: 10.1038/s41467-023-43632-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023] Open
Abstract
Small noncoding RNAs (sRNAs) are crucial regulators of gene expression in bacteria. Acting in concert with major RNA chaperones such as Hfq or ProQ, sRNAs base-pair with multiple target mRNAs and form large RNA-RNA interaction networks. To systematically investigate the RNA-RNA interactome in living cells, we have developed a streamlined in vivo approach iRIL-seq (intracellular RIL-seq). This generic approach is highly robust, illustrating the dynamic sRNA interactomes in Salmonella enterica across multiple stages of growth. We have identified the OmpD porin mRNA as a central regulatory hub that is targeted by a dozen sRNAs, including FadZ cleaved from the conserved 3'UTR of fadBA mRNA. Both ompD and FadZ are activated by CRP, constituting a type I incoherent feed-forward loop in the fatty acid metabolism pathway. Altogether, we have established an approach to profile RNA-RNA interactomes in live cells, highlighting the complexity of RNA regulatory hubs and RNA networks.
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Affiliation(s)
- Fang Liu
- Microbial RNA Systems Biology Unit, Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ziying Chen
- Microbial RNA Systems Biology Unit, Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microorganisms and Infection, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200033, China
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center & Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Shuo Zhang
- Microbial RNA Systems Biology Unit, Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kejing Wu
- Microbial RNA Systems Biology Unit, Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Cheng Bei
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microorganisms and Infection, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200033, China
| | - Chuan Wang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Shanghai Frontiers Science Center of Pathogenic Microorganisms and Infection, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200033, China.
| | - Yanjie Chao
- Microbial RNA Systems Biology Unit, Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, 200031, China.
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China.
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Fodor A, Hess C, Ganas P, Boros Z, Kiss J, Makrai L, Dublecz K, Pál L, Fodor L, Sebestyén A, Klein MG, Tarasco E, Kulkarni MM, McGwire BS, Vellai T, Hess M. Antimicrobial Peptides (AMP) in the Cell-Free Culture Media of Xenorhabdus budapestensis and X. szentirmaii Exert Anti-Protist Activity against Eukaryotic Vertebrate Pathogens including Histomonas meleagridis and Leishmania donovani Species. Antibiotics (Basel) 2023; 12:1462. [PMID: 37760758 PMCID: PMC10525888 DOI: 10.3390/antibiotics12091462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Anti-microbial peptides provide a powerful toolkit for combating multidrug resistance. Combating eukaryotic pathogens is complicated because the intracellular drug targets in the eukaryotic pathogen are frequently homologs of cellular structures of vital importance in the host organism. The entomopathogenic bacteria (EPB), symbionts of entomopathogenic-nematode species, release a series of non-ribosomal templated anti-microbial peptides. Some may be potential drug candidates. The ability of an entomopathogenic-nematode/entomopathogenic bacterium symbiotic complex to survive in a given polyxenic milieu is a coevolutionary product. This explains that those gene complexes that are responsible for the biosynthesis of different non-ribosomal templated anti-microbial protective peptides (including those that are potently capable of inactivating the protist mammalian pathogen Leishmania donovanii and the gallinaceous bird pathogen Histomonas meleagridis) are co-regulated. Our approach is based on comparative anti-microbial bioassays of the culture media of the wild-type and regulatory mutant strains. We concluded that Xenorhabdus budapestensis and X. szentirmaii are excellent sources of non-ribosomal templated anti-microbial peptides that are efficient antagonists of the mentioned pathogens. Data on selective cytotoxicity of different cell-free culture media encourage us to forecast that the recently discovered "easy-PACId" research strategy is suitable for constructing entomopathogenic-bacterium (EPB) strains producing and releasing single, harmless, non-ribosomal templated anti-microbial peptides with considerable drug, (probiotic)-candidate potential.
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Affiliation(s)
- András Fodor
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Pázmány Péter. sétány 1C, H-1117 Budapest, Hungary; (Z.B.); (T.V.)
| | - Claudia Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine (Vetmeduni Vienna), 1210 Vienna, Austria; (C.H.); (P.G.)
| | - Petra Ganas
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine (Vetmeduni Vienna), 1210 Vienna, Austria; (C.H.); (P.G.)
| | - Zsófia Boros
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Pázmány Péter. sétány 1C, H-1117 Budapest, Hungary; (Z.B.); (T.V.)
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Department of Microbiology and Applied Biotechnology, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Páter Károly utca 1, H-2100 Gödöllő, Hungary;
| | - János Kiss
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Department of Microbiology and Applied Biotechnology, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Páter Károly utca 1, H-2100 Gödöllő, Hungary;
| | | | - Károly Dublecz
- Institute of Physiology and Nutrition, Georgikon Campus, Hungarian University of Agriculture and Life Sciences (MATE), Deák Ferenc utca 16, H-8360 Keszthely, Hungary; (K.D.); (L.P.)
| | - László Pál
- Institute of Physiology and Nutrition, Georgikon Campus, Hungarian University of Agriculture and Life Sciences (MATE), Deák Ferenc utca 16, H-8360 Keszthely, Hungary; (K.D.); (L.P.)
| | - László Fodor
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, H-1143 Budapest, Hungary;
| | - Anna Sebestyén
- First Department of Pathology and Experimental Cancer Research, Semmelweis University, H-1085 Budapest, Hungary;
| | - Michael G. Klein
- USDA-ARS & Department of Entomology, The Ohio State University, 13416 Claremont Ave, Cleveland, OH 44130, USA;
| | - Eustachio Tarasco
- Department of Soil, Plant and Food Sciences, University of Bari “Aldo Moro”, Via Amendola 165/A, 70126 Bari, Italy;
| | - Manjusha M. Kulkarni
- Division of Infectious Diseases, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA; (M.M.K.); (B.S.M.)
| | - Bradford S. McGwire
- Division of Infectious Diseases, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA; (M.M.K.); (B.S.M.)
| | - Tibor Vellai
- Department of Genetics, Institute of Biology, Eötvös Loránd University, Pázmány Péter. sétány 1C, H-1117 Budapest, Hungary; (Z.B.); (T.V.)
| | - Michael Hess
- Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine (Vetmeduni Vienna), 1210 Vienna, Austria; (C.H.); (P.G.)
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7
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Yuan B, Li B, Shen H, Duan J, Jia F, Maimaiti Y, Li Y, Li G. Identification of fabclavine derivatives, Fcl-7 and Fcl-8, from Xenorhabdus budapestensis as major antifungal natural products against Rhizoctonia solani. J Appl Microbiol 2023; 134:lxad190. [PMID: 37656887 DOI: 10.1093/jambio/lxad190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/30/2023] [Accepted: 08/21/2023] [Indexed: 09/03/2023]
Abstract
AIMS Black scurf disease, caused by Rhizoctonia solani, is a severe soil-borne and tuber-borne disease, which occurs and spreads in potato growing areas worldwide and poses a serious threat to potato production. New biofungicide is highly desirable for addressing the issue, and natural products (NPs) from Xenorhabdus spp. provide prolific resources for biofungicide development. In this study, we aim to identify antifungal NPs from Xenorhabdus spp. for the management of this disease. METHODS AND RESULTS Out of the 22 Xenorhabdus strains investigated, Xenorhabdus budapestensis 8 (XBD8) was determined to be the most promising candidate with the measured IC50 value of its cell-free supernatant against R. solani as low as 0.19 ml l-1. The major antifungal compound in XBD8 started to be synthesized in the middle logarithmic phase and reached a stable level at stationary phase. Core gene deletion coupled with high-resolution mass spectrometry analysis determined the major antifungal NPs as fabclavine derivatives, Fcl-7 and 8, which showed broad-spectrum bioactivity against important pathogenic fungi. Impressively, the identified fabclavine derivatives effectively controlled black scurf disease in both greenhouse and field experiments, significantly improving tuber quality and increasing with marketable tuber yield from 29 300 to 35 494 kg ha-1, comparable with chemical fungicide fludioxonil. CONCLUSIONS The fabclavine derivatives Fcl-7 and 8 were determined as the major antifungal NPs in XBD8, which demonstrated a bright prospect for the management of black scurf disease.
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Affiliation(s)
- Baoming Yuan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- College of Plant Protection, Hebei Agricultural University, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Baoding 071000, China
| | - Beibei Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium
| | - Hongfei Shen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiaqi Duan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Fenglian Jia
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yushanjiang Maimaiti
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture and Rural Affairs, Research Institute of plant protection Xinjiang Academy of Agricultural Sciences, Urumqi, Xinjiang, 83009, China
| | - Yaning Li
- College of Plant Protection, Hebei Agricultural University, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Baoding 071000, China
| | - Guangyue Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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8
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Bode E, Assmann D, Happel P, Meyer E, Münch K, Rössel N, Bode HB. easyPACId, a Simple Method for Induced Production, Isolation, Identification, and Testing of Natural Products from Proteobacteria. Bio Protoc 2023; 13:e4709. [PMID: 37449040 PMCID: PMC10336570 DOI: 10.21769/bioprotoc.4709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/21/2023] [Accepted: 04/21/2023] [Indexed: 07/18/2023] Open
Abstract
The easyPACId (easy Promoter Activation and Compound Identification) approach is focused on the targeted activation of natural product biosynthetic gene clusters (BGCs) encoding non-ribosomal peptide synthetases (NRPS), polyketide synthases (PKS), NRPS-PKS hybrids, or other BGC classes. It was applied to entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus by exchanging the natural promoter of desired BGCs against the L-arabinose inducible PBAD promoter in ∆hfq mutants of the respective strains. The crude (culture) extracts of the cultivated easyPACId mutants are enriched with the single compound or compound class and can be tested directly against various target organisms without further purification of the produced natural products. Furthermore, isolation and identification of compounds from these mutants is simplified due to the reduced background in the ∆hfq strains. The approach avoids problems often encountered in heterologous expression hosts, chemical synthesis, or tedious extraction of desired compounds from wild-type crude extracts. This protocol describes easyPACId for Xenorhabdus and Photorhabdus, but it was also successfully adapted to Pseudomonas entomophila and might be suitable for other proteobacteria that carry hfq.
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Affiliation(s)
- Edna Bode
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Daniela Assmann
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Petra Happel
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Elmar Meyer
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Karin Münch
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Nicole Rössel
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Helge B. Bode
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Molecular Biotechnology, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
- Chemical Biology, Department of Chemistry, Philipps University Marburg, Marburg, Germany
- Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
- SYNMIKRO (Zentrum für Synthetische Mikrobiologie), Marburg, Germany
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9
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Li B, Yuan B, Duan J, Qin Y, Shen H, Ren J, Francis F, Chen M, Li G. Identification of Fcl-29 as an Effective Antifungal Natural Product against Fusarium graminearum and Combinatorial Engineering Strategy for Improving Its Yield. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:5554-5564. [PMID: 36995163 DOI: 10.1021/acs.jafc.2c09012] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Fusarium head blight (FHB), caused by Fusarium graminearum, whose occurrence and prevalence causes 10-70% wheat production loss, is one of the most destructive diseases influencing the production of wheat globally. To identify the potential natural products (NPs) against F. graminearum, we screened 59 Xenorhabdus strains and discovered that the cell-free supernatant (CFS) of X. budapestensis 14 (XBD14) displays the highest bioactivity. Multiple genetic methods coupled with HRMS/MS analysis determined the major antifungal NP to be Fcl-29, a fabclavine derivative. Fcl-29 was found to effectively control FHB of wheat in the field test and demonstrated broad-spectrum antifungal activity against important pathogenic fungi. The production of Fcl-29 was dramatically improved by 33.82-fold with the combinatorial strategy of genetic engineering (1.66-fold) and fermentation engineering (20.39-fold). The exploration of a new biofungicide in global plant protection is now possible.
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Affiliation(s)
- Beibei Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium
| | - Baoming Yuan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiaqi Duan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Youcai Qin
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Hongfei Shen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jie Ren
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Frédéric Francis
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium
| | - Minghua Chen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Guangyue Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests/Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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10
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Wang H, Zhou Y, Xu S, Zhang B, Cernava T, Ma Z, Chen Y. Enhancement of herbicolin A production by integrated fermentation optimization and strain engineering in Pantoea agglomerans ZJU23. Microb Cell Fact 2023; 22:50. [PMID: 36915090 PMCID: PMC10012537 DOI: 10.1186/s12934-023-02051-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 02/27/2023] [Indexed: 03/14/2023] Open
Abstract
BACKGROUND The lipopeptide herbicolin A (HA) secreted by the biocontrol agent Pantoea agglomerans ZJU23 is a promising antifungal drug to combat fungal pathogens by targeting lipid rafts, both in agricultural and clinical settings. Improvement of HA production would be of great significance in promoting its commercialization. This study aims to enhance the HA production in ZJU23 by combining fermentation optimization and strain engineering. RESULTS Based on the results in the single-factor experiments, corn steep liquor, temperature and initial pH were identified as the significant affecting factors by the Plackett-Burman design. The fermentation medium and conditions were further optimized using the Box-Behnken response surface method, and the HA production of the wild type strain ZJU23 was improved from ~ 87 mg/mL in King's B medium to ~ 211 mg/mL in HA induction (HAI) medium. A transposon library was constructed in ZJU23 to screen for mutants with higher HA production, and two transcriptional repressors for HA biosynthesis, LrhA and PurR, were identified. Disruption of the LrhA gene led to increased mRNA expression of HA biosynthetic genes, and subsequently improved about twofold HA production. Finally, the HA production reached ~ 471 mg/mL in the ΔLrhA mutant under optimized fermentation conditions, which is about 5.4 times higher than before (~ 87 mg/mL). The bacterial suspension of the ΔLrhA mutant fermented in HAI medium significantly enhanced its biocontrol efficacy against gray mold disease and Fusarium crown rot of wheat, showing equivalent control efficacies as the chemical fungicides used in this study. Furthermore, HA was effective against fungicide resistant Botrytis cinerea. Increased HA production substantially improved the control efficacy against gray mold disease caused by a pyrimethanil resistant strain. CONCLUSIONS This study reveals that the transcriptional repressor LrhA negatively regulates HA biosynthesis and the defined HAI medium is suitable for HA production. These findings provide an extended basis for large-scale production of HA and promote biofungicide development based on ZJU23 and HA in the future.
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Affiliation(s)
- Hongkai Wang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China
| | - Yaqi Zhou
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China
| | - Sunde Xu
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China
| | - Boyan Zhang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China
| | - Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Department of Plant Protection, Zhejiang University, Hangzhou, China.
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11
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Zhan C, Chen L, Guo D, Sun J, Duan Y, Zhang P, Li P, Ma L, Xu M, Wang Y, Bao H, Gao G, Liu L, Zhang K. An Intestinal Symbiotic Bacterial Strain of Oscheius chongmingensis Modulates Host Viability at Both Global and Post-Transcriptional Levels. Int J Mol Sci 2022; 23:ijms232314692. [PMID: 36499019 PMCID: PMC9739912 DOI: 10.3390/ijms232314692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/08/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
A rhabditid entomopathogenic nematode (EPN), Oscheius chongmingensis, has a stable symbiotic relationship with the bacterial strain Serratia nematodiphila S1 harbored in its intestines and drastically reduced viability when associated with a non-native strain (186) of the same bacterial species. This nematode is thus a good model for understanding the molecular mechanisms and interactions involved between a nematode host and a member of its intestinal microbiome. Transcriptome analysis and RNA-seq data indicated that expression levels of the majority (8797, 87.59%) of mRNAs in the non-native combination of O. chongmingensis and S. nematodiphila 186 were downregulated compared with the native combination, including strain S1. Accordingly, 88.84% of the total uniq-sRNAs mapped in the O. chongmingensis transcriptome were specific between the two combinations. Six DEGs, including two transcription factors (oc-daf-16 and oc-goa-1) and four kinases (oc-pdk-1, oc-akt-1, oc-rtk, and oc-fak), as well as an up-regulated micro-RNA, oc-miR-71, were found to demonstrate the regulatory mechanisms underlying diminished host viability induced by a non-native bacterial strain. Oc-rtk and oc-fak play key roles in the viability regulation of O. chongmingensis by positively mediating the expression of oc-daf-16 to indirectly impact its longevity and stress tolerances and by negatively regulating the expression of oc-goa-1 to affect the olfactory chemotaxis and fecundity. In response to the stress of invasion by the non-native strain, the expression of oc-miR-71 in the non-native combination was upregulated to downregulate the expression of its targeting oc-pdk-1, which might improve the localization and activation of the transcription factor DAF-16 in the nucleus to induce longevity extension and stress resistance enhancement to some extent. Our findings provide novel insight into comprehension of how nematodes deal with the stress of encountering novel potential bacterial symbionts at the physiological and molecular genetic levels and contribute to improved understanding of host-symbiont relationships generally.
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Affiliation(s)
- Chengxiu Zhan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Long Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Dandan Guo
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jing Sun
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunbin Duan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Panjie Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Pengpeng Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lijun Ma
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Man Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ying Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Haoran Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Guofu Gao
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Liwang Liu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crop (East China), Ministry of Agriculture and Rural Affairs, College of Horiticulture, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: (L.L.); (K.Z.)
| | - Keyun Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: (L.L.); (K.Z.)
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12
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Genome-wide transcription start site mapping in the facultative intracellular pathogen Brucella melitensis by Capping-seq. Gene 2022; 844:146827. [PMID: 35995114 DOI: 10.1016/j.gene.2022.146827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/01/2022] [Accepted: 08/16/2022] [Indexed: 11/20/2022]
Abstract
Brucella melitensis (B. melitensis) is an important facultative intracellular bacterium that causes global zoonotic diseases. Continuous intracellular survival and replication are the main obstruction responsible for the accessibility of prevention and treatment of brucellosis. Bacteria respond to complex environment by regulating gene expression. Many regulatory factors function at loci where RNA polymerase initiates messenger RNA synthesis. However, limited gene annotation is a current obstacle for the research on expression regulation in bacteria. To improve annotation and explore potential functional sites, we proposed a novel genome-wide method called Capping-seq for transcription start site (TSS) mapping in B. melitensis. This technique combines capture of capped primary transcripts with Single Molecule Real-Time (SMRT) sequencing technology. We identified 2,369 TSSs at single nucleotide resolution by Capping-seq. TSSs analysis of Brucella transcripts showed a preference of purine on the TSS positions. Our results revealed that -35 and -10 elements of promoter contained consensus sequences of TTGNNN and TATNNN, respectively. The 5' ends analysis showed that 57% genes are associated with more than one TSS and 47% genes contain long leader regions, suggested potential complex regulation at the 5' ends of genes in B. melitensis. Moreover, we identified 52 leaderless genes that are mainly involved in the metabolic processes. Overall, Capping-seq technology provides a unique solution for TSS determination in prokaryotes. Our findings develop a systematic insight into the primary transcriptome characterization of B. melitensis. This study represents a critical basis for investigating gene regulation and pathogenesis of Brucella.
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13
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Shi YM, Hirschmann M, Shi YN, Bode HB. Cleavage Off-Loading and Post-assembly-Line Conversions Yield Products with Unusual Termini during Biosynthesis. ACS Chem Biol 2022; 17:2221-2228. [PMID: 35860925 PMCID: PMC9396620 DOI: 10.1021/acschembio.2c00367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Piscibactins and photoxenobactins are metallophores and
virulence
factors, whose biosynthetic gene cluster, termed pxb, is the most prevalent polyketide synthase/non-ribosomal peptide
synthetase hybrid cluster across entomopathogenic bacteria. They are
structurally similar to yersiniabactin, which contributes to the virulence
of the human pathogen Yersinia pestis. However, the pxb-derived products feature various
chain lengths and unusual carboxamide, thiocarboxylic acid, and dithioperoxoate
termini, which are rarely found in thiotemplated biosyntheses. Here,
we characterize the pxb biosynthetic logic by gene
deletions, site-directed mutagenesis, and isotope labeling experiments.
Notably, we propose that it involves (1) heterocyclization domains
with various catalytic efficiencies catalyzing thiazoline and amide/thioester
bond formation and (2) putative C–N and C–S bond cleavage
off-loading manners, which lead to products with different chain lengths
and usual termini. Additionally, the post-assembly-line spontaneous
conversions of the biosynthetic end product contribute to production
titers of the other products in the culture medium. This study broadens
our knowledge of thiotemplated biosynthesis and how bacterial host
generate a chemical arsenal.
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Affiliation(s)
- Yi-Ming Shi
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.,Molecular Biotechnology, Department of Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Merle Hirschmann
- Molecular Biotechnology, Department of Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Yan-Ni Shi
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.,Molecular Biotechnology, Department of Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Helge B Bode
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.,Molecular Biotechnology, Department of Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany.,Chemical Biology, Department of Chemistry, Philipps University Marburg, 35043 Marburg, Germany.,Senckenberg Gesellschaft für Naturforschung, 60325 Frankfurt am Main, Germany
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14
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Dominelli N, Jäger HY, Langer A, Brachmann A, Heermann R. High-throughput sequencing analysis reveals genomic similarity in phenotypic heterogeneous Photorhabdus luminescens cell populations. ANN MICROBIOL 2022. [DOI: 10.1186/s13213-022-01677-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Phenotypic heterogeneity occurs in many bacterial populations: single cells of the same species display different phenotypes, despite being genetically identical. The Gram-negative entomopathogenic bacterium Photorhabdus luminescens is an excellent example to investigate bacterial phenotypic heterogeneity. Its dualistic life cycle includes a symbiotic stage interacting with entomopathogenic nematodes (EPNs) and a pathogenic stage killing insect larvae. P. luminescens appears in two phenotypically different cell forms: the primary (1°) and the secondary (2°) cell variants. While 1° cells are bioluminescent, pigmented, and produce a huge set of secondary metabolites, 2° cells lack all these phenotypes. The main difference between both phenotypic variants is that only 1° cells can undergo symbiosis with EPNs, a phenotype that is absent from 2° cells. Recent comparative transcriptome analysis revealed that genes mediating 1° cell-specific traits are modulated differently in 2° cells. Although it was previously suggested that heterogeneity in P. luminescens cells cultures is not genetically mediated by, e.g., larger rearrangements in the genome, the genetic similarity of both cell variants has not clearly been demonstrated yet.
Methods
Here, we analyzed the genomes of both 1° and 2° cells by genome sequencing of each six single 1° and 2° clones that emerged from a single 1° clone after prolonged growth. Using different bioinformatics tools, the sequence data were analyzed for clustered point mutations or genetic rearrangements with respect to the respective phenotypic variant.
Result
We demonstrate that isolated clones of 2° cells that switched from the 1° cell state do not display any noticeable mutation and do not genetically differ from 1° cells.
Conclusion
In summary, we show that the phenotypic differences in P. luminescens cell cultures are obviously not caused by mutations or genetic rearrangements in the genome but truly emerge from phenotypic heterogeneity.
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15
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Global analysis of biosynthetic gene clusters reveals conserved and unique natural products in entomopathogenic nematode-symbiotic bacteria. Nat Chem 2022; 14:701-712. [PMID: 35469007 PMCID: PMC9177418 DOI: 10.1038/s41557-022-00923-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 02/24/2022] [Indexed: 12/27/2022]
Abstract
Microorganisms contribute to the biology and physiology of eukaryotic hosts and affect other organisms through natural products. Xenorhabdus and Photorhabdus (XP) living in mutualistic symbiosis with entomopathogenic nematodes generate natural products to mediate bacteria–nematode–insect interactions. However, a lack of systematic analysis of the XP biosynthetic gene clusters (BGCs) has limited the understanding of how natural products affect interactions between the organisms. Here we combine pangenome and sequence similarity networks to analyse BGCs from 45 XP strains that cover all sequenced strains in our collection and represent almost all XP taxonomy. The identified 1,000 BGCs belong to 176 families. The most conserved families are denoted by 11 BGC classes. We homologously (over)express the ubiquitous and unique BGCs and identify compounds featuring unusual architectures. The bioactivity evaluation demonstrates that the prevalent compounds are eukaryotic proteasome inhibitors, virulence factors against insects, metallophores and insect immunosuppressants. These findings explain the functional basis of bacterial natural products in this tripartite relationship. ![]()
Entomopathogenic nematodes carrying Xenorhabdus and Photorhabdus bacteria prey on insect larvae in the soil. Now, a comprehensive analysis of the bacterial genome has revealed ubiquitous and unique families of biosynthetic gene clusters. Evaluation of the bioactivity of the natural products expressed by the most prevalent cluster families explains the functional basis of bacterial natural products involved in bacteria–nematode–insect interactions.
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16
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Tetsch L. Tödliches Tandem. CHEM UNSERER ZEIT 2022. [DOI: 10.1002/ciuz.202100074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Eckstein S, Brehm J, Seidel M, Lechtenfeld M, Heermann R. Two novel XRE-like transcriptional regulators control phenotypic heterogeneity in Photorhabdus luminescens cell populations. BMC Microbiol 2021; 21:63. [PMID: 33627070 PMCID: PMC7905540 DOI: 10.1186/s12866-021-02116-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/25/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The insect pathogenic bacterium Photorhabdus luminescens exists in two phenotypically different forms, designated as primary (1°) and secondary (2°) cells. Upon yet unknown environmental stimuli up to 50% of the 1° cells convert to 2° cells. Among others, one important difference between the phenotypic forms is that 2° cells are unable to live in symbiosis with their partner nematodes, and therefore are not able to re-associate with them. As 100% switching of 1° to 2° cells of the population would lead to a break-down of the bacteria's life cycle the switching process must be tightly controlled. However, the regulation mechanism of phenotypic switching is still puzzling. RESULTS Here we describe two novel XRE family transcriptional regulators, XreR1 and XreR2, that play a major role in the phenotypic switching process of P. luminescens. Deletion of xreR1 in 1° or xreR2 in 2° cells as well as insertion of extra copies of xreR1 into 2° or xreR2 into 1° cells, respectively, induced the opposite phenotype in either 1° or 2° cells. Furthermore, both regulators specifically bind to different promoter regions putatively fulfilling a positive autoregulation. We found initial evidence that XreR1 and XreR2 constitute an epigenetic switch, whereby XreR1 represses xreR2 expression and XreR2 self-reinforces its own gene by binding to XreR1. CONCLUSION Regulation of gene expression by the two novel XRE-type regulators XreR1 and XreR2 as well as their interplay represents a major regulatory process in phenotypic switching of P. luminescens. A fine-tuning balance between both regulators might therefore define the fate of single cells to convert from the 1° to the 2° phenotype.
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Affiliation(s)
- Simone Eckstein
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany.,Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, Martinsried, Germany
| | - Jannis Brehm
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Michael Seidel
- Ludwig-Maximilians-Universität München, Biozentrum, Bereich Mikrobiologie, Martinsried, Germany
| | - Mats Lechtenfeld
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany
| | - Ralf Heermann
- Johannes-Gutenberg-Universität Mainz, Institut für Molekulare Physiologie, Biozentrum II, Mikrobiologie und Weinforschung, Hanns-Dieter-Hüsch-Weg 17, 55128, Mainz, Germany.
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