1
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Mizgalska D, Rodríguez-Banqueri A, Veillard F, Książęk M, Goulas T, Guevara T, Eckhard U, Potempa J, Gomis-Rüth FX. Structural and functional insights into the C-terminal signal domain of the Bacteroidetes type-IX secretion system. Open Biol 2024; 14:230448. [PMID: 38862016 DOI: 10.1098/rsob.230448] [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: 12/12/2023] [Accepted: 02/20/2024] [Indexed: 06/13/2024] Open
Abstract
Gram-negative bacteria from the Bacteroidota phylum possess a type-IX secretion system (T9SS) for protein secretion, which requires cargoes to have a C-terminal domain (CTD). Structurally analysed CTDs are from Porphyromonas gingivalis proteins RgpB, HBP35, PorU and PorZ, which share a compact immunoglobulin-like antiparallel 3+4 β-sandwich (β1-β7). This architecture is essential as a P. gingivalis strain with a single-point mutant of RgpB disrupting the interaction of the CTD with its preceding domain prevented secretion of the protein. Next, we identified the C-terminus ('motif C-t.') and the loop connecting strands β3 and β4 ('motif Lβ3β4') as conserved. We generated two strains with insertion and replacement mutants of PorU, as well as three strains with ablation and point mutants of RgpB, which revealed both motifs to be relevant for T9SS function. Furthermore, we determined the crystal structure of the CTD of mirolase, a cargo of the Tannerella forsythia T9SS, which shares the same general topology as in Porphyromonas CTDs. However, motif Lβ3β4 was not conserved. Consistently, P. gingivalis could not properly secrete a chimaeric protein with the CTD of peptidylarginine deiminase replaced with this foreign CTD. Thus, the incompatibility of the CTDs between these species prevents potential interference between their T9SSs.
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Affiliation(s)
- Danuta Mizgalska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Arturo Rodríguez-Banqueri
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona, Catalonia 08028, Spain
| | - Florian Veillard
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Mirosław Książęk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Theodoros Goulas
- Department of Food Science and Nutrition, School of Agricultural Sciences, University of Thessaly, Karditsa 43100, Greece
| | - Tibisay Guevara
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona, Catalonia 08028, Spain
| | - Ulrich Eckhard
- Synthetic Structural Biology Group, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona, Catalonia 08028, Spain
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
| | - F Xavier Gomis-Rüth
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona, Catalonia 08028, Spain
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2
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Takahashi M, Yokomichi M, Takei Y, Horaguchi Y, Makabe K, Konno H, Yano S, Kokeguchi S. Domain structure and function of α-1,3-glucanase Agl-EK14 from the gram-negative bacterium Flavobacterium sp. EK-14. J Biosci Bioeng 2024:S1389-1723(24)00133-6. [PMID: 38825558 DOI: 10.1016/j.jbiosc.2024.05.004] [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: 02/28/2024] [Revised: 04/21/2024] [Accepted: 05/08/2024] [Indexed: 06/04/2024]
Abstract
The α-1,3-glucanase Agl-EK14 from Flavobacterium sp. EK-14 comprises a signal peptide (SP), a catalytic domain (CAT), a first immunoglobulin-like domain (Ig1), a second immunoglobulin-like domain (Ig2), a ricin B-like lectin domain (RicinB), and a carboxy-terminal domain (CTD). SP and CTD are predicted to be involved in extracellular secretion, while the roles of Ig1, Ig2, and RicinB are unclear. To clarify their roles, domain deletion enzymes Agl-EK14ΔRicinB, Agl-EK14ΔIg2RicinB, and Agl-EK14ΔIg1Ig2RicinB were constructed. The insoluble α-1,3-glucan hydrolytic, α-1,3-glucan binding, and fungal cell wall hydrolytic activities of the deletion enzymes were almost the same and lower than those of Agl-EK14. Kinetic analysis revealed that the Km values of the deletion enzymes were similar and uniformly higher than those of Agl-EK14. These results suggest that the deletion of RicinB causes a decline in binding and hydrolytic activity and increases the Km value. To confirm the role of RicinB, Ig1, Ig2, and RicinB were fused with green fluorescent protein (GFP). As a result, RicinB-fused GFP (GFP-RicinB) showed binding to insoluble α-1,3-glucan and Aspergillus oryzae cell walls, whereas Ig1- and Ig2-fused GFP did not. These results indicated that RicinB is involved in α-1,3-glucan binding. The fusion protein GFP-Ig1Ig2RicinB was also constructed and GFP-Ig1Ig2RicinB showed strong binding to the cell wall of A. oryzae compared to GFP-RicinB. Gel filtration column chromatography suggested that the strong binding was due to GFP-Ig1Ig2RicinB loosely associated with itself.
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Affiliation(s)
- Masaki Takahashi
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Moe Yokomichi
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Yuki Takei
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Yui Horaguchi
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Koki Makabe
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Hiroyuki Konno
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Shigekazu Yano
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan.
| | - Susumu Kokeguchi
- Department of Bacteriology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
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3
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Zhao Y, Ding WJ, Xu L, Sun JQ. A comprehensive comparative genomic analysis revealed that plant growth promoting traits are ubiquitous in strains of Stenotrophomonas. Front Microbiol 2024; 15:1395477. [PMID: 38817968 PMCID: PMC11138164 DOI: 10.3389/fmicb.2024.1395477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 04/29/2024] [Indexed: 06/01/2024] Open
Abstract
Stenotrophomonas strains, which are often described as plant growth promoting (PGP) bacteria, are ubiquitous in many environments. A total of 213 genomes of strains of Stenotrophomonas were analyzed using comparative genomics to better understand the ecological roles of these bacteria in the environment. The pan-genome of the 213 strains of Stenotrophomonas consists of 27,186 gene families, including 710 core gene families, 11,039 unique genes and 15,437 accessory genes. Nearly all strains of Stenotrophomonas harbor the genes for GH3-family cellulose degradation and GH2- and GH31-family hemicellulose hydrolase, as well as intact glycolysis and tricarboxylic acid cycle pathways. These abilities suggest that the strains of this genus can easily obtain carbon and energy from the environment. The Stenotrophomonas strains can respond to oxidative stress by synthesizing catalase, superoxide dismutase, methionine sulfoxide reductase, and disulfide isomerase, as well as managing their osmotic balance by accumulating potassium and synthesizing compatible solutes, such as betaine, trehalose, glutamate, and proline. Each Stenotrophomonas strain also contains many genes for resistance to antibiotics and heavy metals. These genes that mediate stress tolerance increase the ability of Stenotrophomonas strains to survive in extreme environments. In addition, many functional genes related to attachment and plant colonization, growth promotion and biocontrol were identified. In detail, the genes associated with flagellar assembly, motility, chemotaxis and biofilm formation enable the strains of Stenotrophomonas to effectively colonize host plants. The presence of genes for phosphate-solubilization and siderophore production and the polyamine, indole-3-acetic acid, and cytokinin biosynthetic pathways confer the ability to promote plant growth. These strains can produce antimicrobial compounds, chitinases, lipases and proteases. Each Stenotrophomonas genome contained 1-9 prophages and 17-60 genomic islands, and the genes related to antibiotic and heavy metal resistance and the biosynthesis of polyamines, indole-3-acetic acid, and cytokinin may be acquired by horizontal gene transfer. This study demonstrates that strains of Stenotrophomonas are highly adaptable for different environments and have strong potential for use as plant growth-promoting bacteria.
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Affiliation(s)
- Yang Zhao
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Wen-Jing Ding
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Lian Xu
- Jiangsu Key Lab for Organic Solid Waste Utilization, Educational Ministry Engineering Center of Resource-saving Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Ji-Quan Sun
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
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4
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Saran A, Kim HM, Manning I, Hancock MA, Schmitz C, Madej M, Potempa J, Sola M, Trempe JF, Zhu Y, Davey ME, Zeytuni N. Unveiling the Molecular Mechanisms of the Type-IX Secretion System's Response Regulator: Structural and Functional Insights. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594396. [PMID: 38798656 PMCID: PMC11118453 DOI: 10.1101/2024.05.15.594396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The Type-IX secretion system (T9SS) is a nanomachinery utilized by bacterial pathogens to facilitate infection. The system is regulated by a signaling cascade serving as its activation switch. A pivotal member in this cascade, the response regulator protein PorX, represents a promising drug target to prevent the secretion of virulence factors. Here, we provide a comprehensive characterization of PorX both in vitro and in vivo . First, our structural studies revealed PorX harbours a unique enzymatic effector domain, which, surprisingly, shares structural similarities with the alkaline phosphatase superfamily, involved in nucleotide and lipid signaling pathways. Importantly, such pathways have not been associated with the T9SS until now. Enzymatic characterization of PorX's effector domain revealed a zinc-dependent phosphodiesterase activity, with active site dimensions suitable to accommodate a large substrate. Unlike typical response regulators that dimerize via their receiver domain upon phosphorylation, we found that zinc can also induce conformational changes and promote PorX's dimerization via an unexpected interface. These findings suggest that PorX can serve as a cellular zinc sensor, broadening our understanding of its regulatory mechanisms. Despite the strict conservation of PorX in T9SS-utilizing bacteria, we demonstrate that PorX is essential for virulence factors secretion in Porphyromonas gingivalis and affects metabolic enzymes secretion in the non-pathogenic Flavobacterium johnsoniae , but not for the secretion of gliding adhesins. Overall, this study advances our structural and functional understanding of PorX, highlighting its potential as a druggable target for intervention strategies aimed at disrupting the T9SS and mitigating virulence in pathogenic species.
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5
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Lauber F, Deme JC, Liu X, Kjær A, Miller HL, Alcock F, Lea SM, Berks BC. Structural insights into the mechanism of protein transport by the Type 9 Secretion System translocon. Nat Microbiol 2024; 9:1089-1102. [PMID: 38538833 PMCID: PMC10994853 DOI: 10.1038/s41564-024-01644-7] [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: 10/30/2023] [Accepted: 02/19/2024] [Indexed: 04/06/2024]
Abstract
Secretion systems are protein export machines that enable bacteria to exploit their environment through the release of protein effectors. The Type 9 Secretion System (T9SS) is responsible for protein export across the outer membrane (OM) of bacteria of the phylum Bacteroidota. Here we trap the T9SS of Flavobacterium johnsoniae in the process of substrate transport by disrupting the T9SS motor complex. Cryo-EM analysis of purified substrate-bound T9SS translocons reveals an extended translocon structure in which the previously described translocon core is augmented by a periplasmic structure incorporating the proteins SprE, PorD and a homologue of the canonical periplasmic chaperone Skp. Substrate proteins bind to the extracellular loops of a carrier protein within the translocon pore. As transport intermediates accumulate on the translocon when energetic input is removed, we deduce that release of the substrate-carrier protein complex from the translocon is the energy-requiring step in T9SS transport.
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Affiliation(s)
- Frédéric Lauber
- Department of Biochemistry, University of Oxford, Oxford, UK
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Justin C Deme
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK
| | - Xiaolong Liu
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Andreas Kjær
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Helen L Miller
- Biological Physics Research Group, Department of Physics, University of Oxford, Oxford, UK
| | - Felicity Alcock
- Department of Biochemistry, University of Oxford, Oxford, UK
- Newcastle University Biosciences Institute, Newcastle University, Newcastle, UK
| | - Susan M Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK.
| | - Ben C Berks
- Department of Biochemistry, University of Oxford, Oxford, UK.
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6
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Yang J, Zhang L, Lin S, Li W, Liu C, Yan J, Li S, Long L. Structural insights of a SusD-like protein in marine Bacteroidetes bacteria reveal the molecular basis for chitin recognition and acquisition. FEBS J 2024; 291:584-595. [PMID: 37845429 DOI: 10.1111/febs.16974] [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: 07/24/2023] [Revised: 09/02/2023] [Accepted: 10/12/2023] [Indexed: 10/18/2023]
Abstract
Efficient recognition and transportation of chitin oligosaccharides are crucial steps for the utilization of chitin by heterotrophic bacteria. In this study, we employed structural biological and biochemical approaches to investigate the substrate recognition and acquisition mechanism of a novel chitin-binding SusD-like protein, AqSusD, which is derived from the chitin utilization gene cluster of a marine Bacteroides strain (Aquimarina sp. SCSIO 21287). We resolved the crystal structures of the AqSusD apo-protein and its complex with chitin oligosaccharides. Our results revealed that some crucial residues (Gln67, Phe87, and Asp276) underwent significant conformational changes to form tighter substrate binding sites for ligand binding. Moreover, we identified the functions of key amino acid residues and discovered that π-π stacking and hydrogen bonding between AqSusD and the ligand played significant roles in recognition of the protein for chitin oligosaccharide binding. Based on our findings and previous investigations, we put forward a model for the mechanism of chitin oligosaccharide recognition, capture, and transport by AqSusD, in collaboration with the membrane protein AqSusC. Our study deepens the understanding of the molecular-level "selfish" use of polysaccharides such as chitin by Bacteroides.
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Affiliation(s)
- Jian Yang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Liping Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Shanshan Lin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Wei Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Chen Liu
- Guangzhou Quality Supervision and Testing Institute, China
| | - Jingheng Yan
- Guangzhou Quality Supervision and Testing Institute, China
| | - Shubo Li
- College of Light Industry and Food Engineering, Guangxi University, Nanning, China
| | - Lijuan Long
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
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7
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Takahashi M, Yano S, Horaguchi Y, Otsuka Y, Suyotha W, Makabe K, Konno H, Kokeguchi S. α-1,3-Glucanase from the gram-negative bacterium Flavobacterium sp. EK-14 hydrolyzes fungal cell wall α-1,3-glucan. Sci Rep 2023; 13:21420. [PMID: 38049513 PMCID: PMC10696023 DOI: 10.1038/s41598-023-48627-y] [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: 09/21/2023] [Accepted: 11/28/2023] [Indexed: 12/06/2023] Open
Abstract
The glycoside hydrolase (GH) 87 α-1,3-glucanase (Agl-EK14) gene was cloned from the genomic DNA of the gram-negative bacterium Flavobacterium sp. EK14. The gene consisted of 2940 nucleotides and encoded 980 amino acid residues. The deduced amino acid sequence of Agl-EK14 included a signal peptide, a catalytic domain, a first immunoglobulin-like domain, a second immunoglobulin-like domain, a ricin B-like lectin domain, and a carboxyl-terminal domain (CTD) involved in extracellular secretion. Phylogenetic analysis of the catalytic domain of GH87 enzymes suggested that Agl-EK14 is distinct from known clusters, such as clusters composed of α-1,3-glucanases from bacilli and mycodextranases from actinomycetes. Agl-EK14 without the signal peptide and CTD hydrolyzed α-1,3-glucan, and the reaction residues from 1 and 2% substrates were almost negligible after 1440 min reaction. Agl-EK14 hydrolyzed the cell wall preparation of Aspergillus oryzae and released glucose, nigerose, and nigero-triose from the cell wall preparation. After treatment of A. oryzae live mycelia with Agl-EK14 (at least 0.5 nmol/ml), mycelia were no longer stained by red fluorescent protein-fused α-1,3-glucan binding domains of α-1,3-glucanase Agl-KA from Bacillus circulans KA-304. Results suggested that Agl-EK14 can be applied to a fungal cell wall lytic enzyme.
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Affiliation(s)
- Masaki Takahashi
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Shigekazu Yano
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan.
| | - Yui Horaguchi
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Yuitsu Otsuka
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Wasana Suyotha
- Enzyme Technology Laboratory, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, 90112, Thailand
| | - Koki Makabe
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Hiroyuki Konno
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Susumu Kokeguchi
- Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700-8525, Japan
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8
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Wang M, Zheng N, Li X, Zhao K, Xie BB. Enrichment Pretreatment Expands the Microbial Diversity Cultivated from Marine Sediments. Microorganisms 2023; 11:2771. [PMID: 38004782 PMCID: PMC10673404 DOI: 10.3390/microorganisms11112771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
The majority of the microbial diversity in nature has not been recovered through cultivation. Enrichment is a classical technique widely used in the selective cultivation of specific taxa. Whether enrichment is suitable for cultivation studies that aim to recover large numbers of species remains little explored. To address this issue, we evaluated the potential of enrichment pretreatment in the cultivation of bacteria from marine sediments. Upon obtaining and classifying a total of 943 pure cultures from chitin and cellulose enrichment pretreatment systems and a control system, our results showed that species obtained using enrichment pretreatment differed greatly from those without enrichment. Multiple enrichment media and different enrichment times increased the number of cultivated species in a sample. Amplicon sequencing showed that the increased relative abundance during pretreatment contributed greatly to bacterial cultivation. The testing of degradation abilities against chitin and cellulose and the whole-genome sequencing of representative strains suggested that microorganism-microorganism interactions play roles in the expanded diversity of cultivated bacteria. This study provides new insights into the abilities of enrichment in exploring cultivable diversity and mining microbial resources.
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Affiliation(s)
| | | | | | | | - Bin-Bin Xie
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (M.W.); (N.Z.); (X.L.); (K.Z.)
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9
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Sahoo A, Vivek-Ananth RP, Chivukula N, Rajaram SV, Mohanraj K, Khare D, Acharya C, Samal A. T9GPred: A Comprehensive Computational Tool for the Prediction of Type 9 Secretion System, Gliding Motility, and the Associated Secreted Proteins. ACS OMEGA 2023; 8:34091-34102. [PMID: 37744817 PMCID: PMC10515386 DOI: 10.1021/acsomega.3c05155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 08/24/2023] [Indexed: 09/26/2023]
Abstract
Type 9 secretion system (T9SS) is one of the least characterized secretion systems exclusively found in the Bacteroidetes phylum, which comprises various environmental and economically relevant bacteria. While T9SS plays a central role in bacterial movement termed gliding motility, survival, and pathogenicity, there is an unmet need for a comprehensive tool that predicts T9SS, gliding motility, and proteins secreted via T9SS. In this study, we develop such a computational tool, Type 9 secretion system and Gliding motility Prediction (T9GPred). To build this tool, we manually curated published experimental evidence and identified mandatory components for T9SS and gliding motility prediction. We also compiled experimentally characterized proteins secreted via T9SS and determined the presence of three unique types of C-terminal domain signals, and these insights were leveraged to predict proteins secreted via T9SS. Notably, using recently published experimental evidence, we show that T9GPred has high predictive power. Thus, we used T9GPred to predict the presence of T9SS, gliding motility, and associated secreted proteins across 693 completely sequenced Bacteroidetes strains. T9GPred predicted 402 strains to have T9SS, of which 327 strains are also predicted to exhibit gliding motility. Further, T9GPred also predicted putative secreted proteins for the 402 strains. In a nutshell, T9GPred is a novel computational tool for systems-level prediction of T9SS and streamlining future experimentation. The source code of the computational tool is available in our GitHub repository: https://github.com/asamallab/T9GPred. The tool and its predicted results are compiled in a web server available at: https://cb.imsc.res.in/t9gpred/.
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Affiliation(s)
- Ajaya
Kumar Sahoo
- The
Institute of Mathematical Sciences (IMSc), Chennai 600113, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
| | - R. P. Vivek-Ananth
- The
Institute of Mathematical Sciences (IMSc), Chennai 600113, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
| | - Nikhil Chivukula
- The
Institute of Mathematical Sciences (IMSc), Chennai 600113, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
| | - Shri Vishalini Rajaram
- The
Institute of Mathematical Sciences (IMSc), Chennai 600113, India
- Centre
for Biotechnology, Anna University, Chennai 600025, India
| | - Karthikeyan Mohanraj
- Institute
for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden 01307, Germany
| | - Devanshi Khare
- Molecular
Biology Division, Bhabha Atomic Research
Centre, Mumbai 400085, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
| | - Celin Acharya
- Molecular
Biology Division, Bhabha Atomic Research
Centre, Mumbai 400085, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
| | - Areejit Samal
- The
Institute of Mathematical Sciences (IMSc), Chennai 600113, India
- Homi
Bhabha National Institute (HBNI), Mumbai 400094, India
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10
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Kondo Y, Ohara K, Fujii R, Nakai Y, Sato C, Naito M, Tsukuba T, Kadowaki T, Sato K. Transposon mutagenesis and genome sequencing identify two novel, tandem genes involved in the colony spreading of Flavobacterium collinsii, isolated from an ayu fish, Plecoglossus altivelis. Front Cell Infect Microbiol 2023; 13:1095919. [PMID: 36844397 PMCID: PMC9950754 DOI: 10.3389/fcimb.2023.1095919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/16/2023] [Indexed: 02/12/2023] Open
Abstract
Bacteria of the family Flavobacteriaceae (flavobacteria) primarily comprise nonpathogenic bacteria that inhabit soil and water (both marine and freshwater). However, some bacterial species in the family, including Flavobacterium psychrophilum and Flavobacterium columnare, are known to be pathogenic to fish. Flavobacteria, including the abovementioned pathogenic bacteria, belong to the phylum Bacteroidota and possess two phylum-specific features, gliding motility and a protein secretion system, which are energized by a common motor complex. Herein, we focused on Flavobacterium collinsii (GiFuPREF103) isolated from a diseased fish (Plecoglossus altivelis). Genomic analysis of F. collinsii GiFuPREF103 revealed the presence of a type IX secretion system and additional genes associated with gliding motility and spreading. Using transposon mutagenesis, we isolated two mutants with altered colony morphology and colony spreading ability; these mutants had transposon insertions in pep25 and lbp26. The glycosylation material profiles revealed that these mutants lacked the high-molecular-weight glycosylated materials present in the wild-type strain. In addition, the wild-type strains exhibited fast cell population movement at the edge of the spreading colony, whereas reduced cell population behavior was observed in the pep25- and lbp26-mutant strains. In the aqueous environment, the surface layers of these mutant strains were more hydrophobic, and they formed biofilms with enhanced microcolony growth compared to those with the wild-type. In Flavobacterium johnsoniae, the Fjoh_0352 and Fjoh_0353 mutant strains were generated, which were based on the ortholog genes of pep25 and lbp26. In these F. johnsoniae mutants, as in F. collinsii GiFuPREF103, colonies with diminished spreading capacity were formed. Furthermore, cell population migration was observed at the edge of the colony in wild-type F. johnsoniae, whereas individual cells, and not cell populations, migrated in these mutant strains. The findings of the present study indicate that pep25 and lbp26 contribute to the colony spreading of F. collinsii.
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Affiliation(s)
- Yoshio Kondo
- Department of Pediatric Dentistry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan,*Correspondence: Yoshio Kondo, ; Keiko Sato,
| | - Kenichi Ohara
- Gifu Prefectural Research Institute for Fisheries and Aquatic Environments, Gifu, Japan
| | - Ryoji Fujii
- Gifu Prefectural Research Institute for Fisheries and Aquatic Environments, Gifu, Japan
| | - Yudai Nakai
- Department of Frontier Oral Science, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Chikara Sato
- School of Integrative and Global Majors (SIGMA), University of Tsukuba, Ibaraki, Japan,Biological Science Course, Graduate School of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan,Division of Immune Homeostasis, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan,Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan
| | - Mariko Naito
- Department of Microbiology and Oral Infection, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Takayuki Tsukuba
- Department of Dental Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Tomoko Kadowaki
- Department of Frontier Oral Science, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Keiko Sato
- Department of Frontier Oral Science, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan,*Correspondence: Yoshio Kondo, ; Keiko Sato,
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11
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Shibata S, Tahara YO, Katayama E, Kawamoto A, Kato T, Zhu Y, Nakane D, Namba K, Miyata M, McBride MJ, Nakayama K. Filamentous structures in the cell envelope are associated with bacteroidetes gliding machinery. Commun Biol 2023; 6:94. [PMID: 36690840 PMCID: PMC9870892 DOI: 10.1038/s42003-023-04472-3] [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: 10/26/2022] [Accepted: 01/12/2023] [Indexed: 01/24/2023] Open
Abstract
Many bacteria belonging to the phylum Bacteroidetes move on solid surfaces, called gliding motility. In our previous study with the Bacteroidetes gliding bacterium Flavobacterium johnsoniae, we proposed a helical loop track model, where adhesive SprB filaments are propelled along a helical loop on the cell surface. In this study, we observed the gliding cell rotating counterclockwise about its axis when viewed from the rear to the advancing direction of the cell and revealed that one labeled SprB focus sometimes overtook and passed another SprB focus that was moving in the same direction. Several electron microscopic analyses revealed the presence of a possible multi-rail structure underneath the outer membrane, which was associated with SprB filaments and contained GldJ protein. These results provide insights into the mechanism of Bacteroidetes gliding motility, in which the SprB filaments are propelled along tracks that may form a multi-rail system underneath the outer membrane. The insights may give clues as to how the SprB filaments get their driving force.
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Affiliation(s)
- Satoshi Shibata
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
- Division of Bacteriology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Tottori, Japan.
| | - Yuhei O Tahara
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka, Japan
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka, Japan
| | - Eisaku Katayama
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka, Japan
- Waseda Research Institute for Science and Engineering, Okubo Shinjyuku, Tokyo, Japan
| | - Akihiro Kawamoto
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Takayuki Kato
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Yongtao Zhu
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53201, USA
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, China
| | - Daisuke Nakane
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Makoto Miyata
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka, Japan
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka, Japan
| | - Mark J McBride
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53201, USA
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
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12
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Wang J, Chen Y, He X, Du X, Gao Y, Shan X, Hu Z, Hu Q. PaR1 secreted by the type IX secretion system is a protective antigen of Riemerella anatipestifer. Front Microbiol 2023; 13:1082712. [PMID: 36713192 PMCID: PMC9874225 DOI: 10.3389/fmicb.2022.1082712] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Abstract
Riemerella anatipestifer mainly infects domestic ducks, geese, turkeys, and other birds, and causes considerable economic losses to the global duck industry. Previous studies have shown that concentrated cell-free culture filtrates of R. anatipestifer induce highly significant protection against homologous challenge. In this study, 12 immunogenic proteins were identified in the culture supernatant of R. anatipestifer strain Yb2 with immunoproteomic analysis. Of these, three immunogenic proteins, AS87_RS06600 (designated "PaR1" in this study), AS87_RS09020, and AS87_RS09965, which appeared in more than three spots on the western-blotted membrane, were expressed in Escherichia coli and purified. Animal experiments showed that the recombinant PaR1 (rPaR1) protein protected 41.67% of immunized ducklings against challenge with virulent Yb2, whereas rAS87_RS09020 or rAS87_RS09965 did not, and that ducklings immunized once with rPaR1 were 20, 40, and 0% protected from challenge with R. anatipestifer strains WJ4 (serotype 1), Yb2 (serotype 2), and HXb2 (serotype 10), respectively. In addition, rPaR1 immunized rabbit serum showed bactericidal activity against strain Yb2 at a titer of 1:8. These results indicate that rPaR1 of strain Yb2 protects against homologous challenge. Amino acid homology analysis show that PaR1 is a non-serotype-specific protein among different R. anatipestifer serotypes. Furthermore, PaR1 is mainly secreted outside the cell through the T9SS. Overall, our results demonstrate that R. anatipestifer PaR1 is a non-serotype-specific protective protein secreted by the T9SS.
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13
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Astafyeva Y, Gurschke M, Streit WR, Krohn I. Interplay between the microalgae Micrasterias radians and its symbiont Dyadobacter sp. HH091. Front Microbiol 2022; 13:1006609. [PMID: 36312980 PMCID: PMC9606717 DOI: 10.3389/fmicb.2022.1006609] [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] [Received: 07/29/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Based on previous research, related to detailed insight into mutualistic collaboration of microalga and its microbiome, we established an artificial plant-bacteria system of the microalga Micrasterias radians MZCH 672 and the bacterial isolate Dyadobacter sp. HH091. The bacteria, affiliated with the phylum Bacteroidota, strongly stimulated growth of the microalga when it was added to axenic algal cultures. For further advances, we studied the isolate HH091 and its interaction with the microalga M. radians using transcriptome and extensive genome analyses. The genome of HH091 contains predicted polysaccharide utilizing gene clusters co-working with the type IX secretion system (T9SS) and conceivably involved in the algae-bacteria liaison. Here, we focus on characterizing the mechanism of T9SS, implementing the attachment and invasion of microalga by Dyadobacter sp. HH091. Omics analysis exposed T9SS genes: gldK, gldL, gldM, gldN, sprA, sprE, sprF, sprT, porU and porV. Besides, gld genes not considered as the T9SS components but required for gliding motility and protein secretion (gldA, gldB, gldD, gldF, gldG, gldH, gldI, gldJ), were also identified at this analysis. A first model of T9SS apparatus of Dyadobacter was proposed in a course of this research. Using the combination of fluorescence labeling of Dyadobacter sp. HH091, we examined the bacterial colonisation and penetration into the cell wall of the algal host M. radians MZCH 672.
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Saran A, Weerasinghe N, Thibodeaux CJ, Zeytuni N. Purification, crystallization and crystallographic analysis of the PorX response regulator associated with the type IX secretion system. Acta Crystallogr F Struct Biol Commun 2022; 78:354-362. [PMID: 36189719 PMCID: PMC9527653 DOI: 10.1107/s2053230x22008500] [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: 07/25/2022] [Accepted: 08/24/2022] [Indexed: 11/10/2022] Open
Abstract
Pathogenic bacteria utilize specialized macromolecular secretion systems to transport virulence factors across membrane(s) and manipulate their infected host. To date, 11 secretion systems have been identified, including the type IX secretion system (T9SS) associated with human, avian and farmed-fish diseases. As a bacterial secretion system, the T9SS also facilitates gliding motility and the degradation of different macromolecules by the secretion of metabolic enzymes in nonpathogenic bacteria. PorX is a highly conserved protein that regulates the transcription of essential T9SS components and additionally mediates the function of T9SS via direct interaction with PorL, the rotary motor protein of the T9SS. PorX is also a member of a two-component system regulatory cascade, where it serves as the response regulator that relays a signal transduced from a conserved sensor histidine kinase, PorY, to a designated sigma factor. Here, the recombinant expression and purification of PorX homologous proteins from the pathogenic bacterium Porphyromonas gingivalis and the nonpathogenic bacterium Flavobacterium johnsoniae are reported. A bioinformatical characterization of the different domains comprising the PorX protein is also provided, and the crystallization and X-ray analysis of PorX from F. johnsoniae are reported.
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Affiliation(s)
- Anshu Saran
- The Department of Anatomy and Cell Biology and the Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Nuwani Weerasinghe
- The Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | | | - Natalie Zeytuni
- The Department of Anatomy and Cell Biology and the Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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15
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Genome-Wide Analysis and Characterization of the Riemerella anatipestifer Putative T9SS Secretory Proteins with a Conserved C-Terminal Domain. J Bacteriol 2022; 204:e0007322. [PMID: 35670588 DOI: 10.1128/jb.00073-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Recent studies have shown that the R. anatipestifer type IX secretion system (T9SS) acts as a crucial virulence factor. We previously identified two T9SS component proteins, GldK and GldM, and one T9SS effector metallophosphoesterase, which play important roles in bacterial virulence. In this study, 19 T9SS-secreted proteins that contained a conserved T9SS C-terminal domain (CTD) were predicted in R. anatipestifer strain Yb2 by searching for CTD-encoding sequences in the whole genome. The proteins were confirmed with a liquid chromatography-tandem mass spectrometry analysis of the bacterial culture supernatant. Nine of them were reported in our previous study. We generated recombinant proteins and mouse antisera for the 19 predicted proteins to confirm their expression in the bacterial culture supernatant and in bacterial cells. Western blotting indicated that the levels of 14 proteins were significantly reduced in the T9SS mutant Yb2ΔgldM culture medium but were increased in the bacterial cells. RT-qPCR indicated that the expression of these genes did not differ between the wild-type strain Yb2 and the T9SS mutant Yb2ΔgldM. Nineteen mutant strains were successfully constructed to determine their virulence and proteolytic activity, which indicated that seven proteins are associated with bacterial virulence, and two proteins, AS87_RS04190 and AS87_RS07295, are protease-activity-associated virulence factors. In summary, we have identified at least 19 genes encoding T9SS-secreted proteins in the R. anatipestifer strain Yb2 genome, which encode multiple functions associated with the bacterium's virulence and proteolytic activity. IMPORTANCE Riemerella anatipestifer T9SS plays an important role in bacterial virulence. We have previously reported nine R. anatipestifer T9SS-secreted proteins and clarified the function of the metallophosphoesterase. In this study, we identified 10 more secreted proteins associated with the R. anatipestifer T9SS, in addition to the nine previously reported. Of these, 14 proteins showed significantly reduced secretion into the bacterial culture medium but increased expression in the bacterial cells of the T9SS mutant Yb2ΔgldM; seven proteins were shown to be associated with bacterial virulence; and two proteins, AS87_RS04190 and AS87_RS07295, were shown to be protease-activity-associated virulence factors. Thus, we have demonstrated that multiple R. anatipestifer T9SS-secreted proteins function in virulence and proteolytic activity.
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16
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Type B CTD Proteins Secreted by the Type IX Secretion System Associate with PorP-like Proteins for Cell Surface Anchorage. Int J Mol Sci 2022; 23:ijms23105681. [PMID: 35628493 PMCID: PMC9143113 DOI: 10.3390/ijms23105681] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 02/07/2023] Open
Abstract
The Bacteroidetes type IX secretion system (T9SS) consists of at least 20 components that translocate proteins with type A or type B C-terminal domain (CTD) signals across the outer membrane (OM). While type A CTD proteins are anchored to the cell surface via covalent linkage to the anionic lipopolysaccharide, it is still unclear how type B CTD proteins are anchored to the cell surface. Moreover, very little is known about the PorE and PorP components of the T9SS. In this study, for the first time, we identified a complex comprising the OM β-barrel protein PorP, the OM-associated periplasmic protein PorE and the type B CTD protein PG1035. Cross-linking studies supported direct interactions between PorE-PorP and PorP-PG1035. Furthermore, we show that the formation of the PorE-PorP-PG1035 complex was independent of PorU and PorV. Additionally, the Flavobacterium johnsoniae PorP-like protein, SprF, was found bound to the major gliding motility adhesin, SprB, which is also a type B CTD protein. Together, these results suggest that type B-CTD proteins may anchor to the cell surface by binding to their respective PorP-like proteins.
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Yurgel SN, Nadeem M, Cheema M. Microbial Consortium Associated with Crustacean Shells Composting. Microorganisms 2022; 10:1033. [PMID: 35630475 PMCID: PMC9145653 DOI: 10.3390/microorganisms10051033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 02/04/2023] Open
Abstract
Soil microbes play an essential role in the biodegradation of crustacean shells, which is the process of sustainable bioconversion to chitin derivatives ultimately resulting in the promotion of plant growth properties. While a number of microorganisms with chitinolytic properties have been characterized, little is known about the microbial taxa that participate in this process either by active chitin degradation or by facilitation of this activity through nutritional cooperation and composting with the chitinolytic microorganisms. In this study, we evaluated the transformation of the soil microbiome triggered by close approximation to the green crab shell surface. Our data indicate that the microbial community associated with green crab shell matter undergoes significant specialized changes, which was reflected in a decreased fungal and bacterial Shannon diversity and evenness and in a dramatic alteration in the community composition. The relative abundance of several bacterial and fungal genera including bacteria Flavobacterium, Clostridium, Pseudomonas, and Sanguibacter and fungi Mortierella, Mycochlamys, and Talaromyces were increased with approximation to the shell surface. Association with the shell triggered significant changes in microbial cooperation that incorporate microorganisms that were previously reported to be involved in chitin degradation as well as ones with no reported chitinolytic activity. Our study indicates that the biodegradation of crab shells in soil incorporates a consortium of microorganisms that might provide a more efficient way for bioconversion.
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Affiliation(s)
- Svetlana N. Yurgel
- USDA-ARS, Grain Legume Genetics and Physiology Research Unit, Prosser, WA 99350, USA
| | - Muhammad Nadeem
- School of Science and the Environment, Grenfell Campus, Memorial University of Newfoundland and Labrador, Corner Brook, NL A2H 5G4, Canada; (M.N.); (M.C.)
| | - Mumtaz Cheema
- School of Science and the Environment, Grenfell Campus, Memorial University of Newfoundland and Labrador, Corner Brook, NL A2H 5G4, Canada; (M.N.); (M.C.)
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18
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Riemerella anatipestifer T9SS Effector SspA Functions in Bacterial Virulence and Defending Natural Host Immunity. Appl Environ Microbiol 2022; 88:e0240921. [PMID: 35575548 DOI: 10.1128/aem.02409-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Recent studies have shown that the R. anatipestifer type IX secretion system (T9SS) is a crucial factor in bacterial virulence. The AS87_RS04190 protein was obviously missing from the secreted proteins of the T9SS mutant strain Yb2ΔgldM. A bioinformatic analysis indicated that the AS87_RS04190 protein contains a T9SS C-terminal domain sequence and encodes a putative subtilisin-like serine protease (SspA). To determine the role of the putative SspA protein in R. anatipestifer pathogenesis and proteolysis, we constructed two strains with an sspA mutation and complementation, respectively, and determined their median lethal doses, their bacterial loads in infected duck blood, and their adherence to and invasion of cells. Our results demonstrate that the SspA protein functions in bacterial virulence. It is also associated with the bacterial protease activity and has a conserved catalytic triad structure (Asp126, His158, and Ser410), which is necessary for protein function. The optimal reactive pH and temperature were determined to be 7.0 and 50°C, respectively, and Km and Vmax were determined to be 10.15 mM and 246.96 U/mg, respectively. The enzymatic activity of SspA is activated by Ca2+, Mg2+, and Mn2+ and inhibited by Cu2+ and EDTA. SspA degrades gelatin, fibrinogen, and bacitracin LL-37. These results demonstrate that SspA is an effector protein of T9SS and functions in R. anatipestifer virulence and its proteolysis of gelatin, fibrinogen, and bacitracin LL-37. IMPORTANCE In recent years, Riemerella anatipestifer T9SS has been reported to act as a virulence factor. However, the functions of the proteins secreted by R. anatipestifer T9SS are not entirely clear. In this study, a secreted subtilisin-like serine protease SspA was shown to be associated with R. anatipestifer virulence, host complement evasion, and degradation of gelatin, fibrinogen, and LL-37. The enzymatic activity of recombinant SspA was determined, and its Km and Vmax were 10.15 mM and 246.96 U/mg, respectively. Three conserved sites (Asp126, His158, and Ser410) are necessary for the protein's function. The median lethal dose of the sspA-deleted mutant strain was reduced >10,000-fold, indicating that SspA is an important virulence factor. In summary, we demonstrate that the R. anatipestifer AS87_RS04190 gene encodes an important T9SS effector, SspA, which plays an important role in bacterial virulence.
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Trivedi A, Gosai J, Nakane D, Shrivastava A. Design Principles of the Rotary Type 9 Secretion System. Front Microbiol 2022; 13:845563. [PMID: 35620107 PMCID: PMC9127263 DOI: 10.3389/fmicb.2022.845563] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/17/2022] [Indexed: 01/05/2023] Open
Abstract
The Fo ATP synthase, the bacterial flagellar motor, and the bacterial type 9 secretion system (T9SS) are the three known proton motive force driven biological rotary motors. In this review, we summarize the current information on the nuts and bolts of T9SS. Torque generation by T9SS, its role in gliding motility of bacteria, and the mechanism via which a T9SS-driven swarm shapes the microbiota are discussed. The knowledge gaps in our current understanding of the T9SS machinery are outlined.
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Affiliation(s)
- Abhishek Trivedi
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
| | - Jitendrapuri Gosai
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
| | - Daisuke Nakane
- Department of Engineering Science, The University of Electro-Communications, Tokyo, Japan
| | - Abhishek Shrivastava
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
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20
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Vincent MS, Comas Hervada C, Sebban-Kreuzer C, Le Guenno H, Chabalier M, Kosta A, Guerlesquin F, Mignot T, McBride MJ, Cascales E, Doan T. Dynamic proton-dependent motors power type IX secretion and gliding motility in Flavobacterium. PLoS Biol 2022; 20:e3001443. [PMID: 35333857 PMCID: PMC8986121 DOI: 10.1371/journal.pbio.3001443] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/06/2022] [Accepted: 03/01/2022] [Indexed: 02/06/2023] Open
Abstract
Motile bacteria usually rely on external apparatus like flagella for swimming or pili for twitching. By contrast, gliding bacteria do not rely on obvious surface appendages to move on solid surfaces. Flavobacterium johnsoniae and other bacteria in the Bacteroidetes phylum use adhesins whose movement on the cell surface supports motility. In F. johnsoniae, secretion and helicoidal motion of the main adhesin SprB are intimately linked and depend on the type IX secretion system (T9SS). Both processes necessitate the proton motive force (PMF), which is thought to fuel a molecular motor that comprises the GldL and GldM cytoplasmic membrane proteins. Here, we show that F. johnsoniae gliding motility is powered by the pH gradient component of the PMF. We further delineate the interaction network between the GldLM transmembrane helices (TMHs) and show that conserved glutamate residues in GldL TMH2 are essential for gliding motility, although having distinct roles in SprB secretion and motion. We then demonstrate that the PMF and GldL trigger conformational changes in the GldM periplasmic domain. We finally show that multiple GldLM complexes are distributed in the membrane, suggesting that a network of motors may be present to move SprB along a helical path on the cell surface. Altogether, our results provide evidence that GldL and GldM assemble dynamic membrane channels that use the proton gradient to power both T9SS-dependent secretion of SprB and its motion at the cell surface. Motile bacteria usually rely on external apparatus like flagella or pili, but gliding bacteria do not rely on obvious surface appendages for their movement. This study shows that bacteria in the phylum Bacteroidetes use proton-dependent motors to power protein secretion and gliding motility.
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Affiliation(s)
- Maxence S. Vincent
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Caterina Comas Hervada
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Corinne Sebban-Kreuzer
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Hugo Le Guenno
- Microscopy Core Facility, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université, Marseille, France
| | - Maïalène Chabalier
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Artemis Kosta
- Microscopy Core Facility, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université, Marseille, France
| | - Françoise Guerlesquin
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7283, Marseille, France
| | - Mark J. McBride
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Eric Cascales
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
- * E-mail: (EC); (TD)
| | - Thierry Doan
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
- * E-mail: (EC); (TD)
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Protein Interactome Analysis of the Type IX Secretion System Identifies PorW as the Missing Link between the PorK/N Ring Complex and the Sov Translocon. Microbiol Spectr 2022; 10:e0160221. [PMID: 35019767 PMCID: PMC8754138 DOI: 10.1128/spectrum.01602-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The type IX secretion system (T9SS) transports cargo proteins through the outer membrane of Bacteroidetes and attaches them to the cell surface for functions including pathogenesis, gliding motility, and degradation of carbon sources. The T9SS comprises at least 20 different proteins and includes several modules: the trans-envelope core module comprising the PorL/M motor and the PorK/N ring, the outer membrane Sov translocon, and the cell attachment complex. However, the spatial organization of these modules is unknown. We have characterized the protein interactome of the Sov translocon in Porphyromonas gingivalis and identified Sov-PorV-PorA as well as Sov-PorW-PorN-PorK to be novel networks. PorW also interacted with PGN_1783 (PorD), which was required for maximum secretion efficiency. The identification of PorW as the missing link completes a continuous interaction network from the PorL/M motor to the Sov translocon, providing a pathway for cargo delivery and energy transduction from the inner membrane to the secretion pore. IMPORTANCE The T9SS is a newly identified protein secretion system of the Fibrobacteres-Chlorobi-Bacteroidetes superphylum used by pathogens associated with diseases of humans, fish, and poultry for the secretion and cell surface attachment of virulence factors. The T9SS comprises three known modules: (i) the trans-envelope core module comprising the PorL/M motor and the PorK/N ring, (ii) the outer membrane Sov translocon, and (iii) the cell surface attachment complex. The spatial organization and interaction of these modules have been a mystery. Here, we describe the protein interactome of the Sov translocon in the human pathogen Porphyromonas gingivalis and have identified PorW as the missing link which bridges PorN with Sov and so completes a continuous interaction network from the PorL/M motor to the Sov translocon, providing, for the first time, a pathway for cargo delivery and energy transduction from the inner membrane to the secretion pore.
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Type IX secretion system effectors and virulence of the model Flavobacterium columnare strain MS-FC-4. Appl Environ Microbiol 2021; 88:e0170521. [PMID: 34818105 DOI: 10.1128/aem.01705-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Flavobacterium columnare causes columnaris disease in wild and cultured freshwater fish and is a major problem for sustainable aquaculture worldwide. The F. columnare type IX secretion system (T9SS) secretes many proteins and is required for virulence. The T9SS component GldN is required for secretion and for gliding motility over surfaces. Genetic manipulation of F. columnare is inefficient, which has impeded identification of secreted proteins that are critical for virulence. Here we identified a virulent wild-type F. columnare strain (MS-FC-4) that is highly amenable to genetic manipulation. This facilitated isolation and characterization of two deletion mutants lacking core components of the T9SS. Deletion of gldN disrupted protein secretion and gliding motility and eliminated virulence in zebrafish and rainbow trout. Deletion of porV disrupted secretion and virulence but not motility. Both mutants exhibited decreased extracellular proteolytic, hemolytic, and chondroitin sulfate lyase activities. They also exhibited decreased biofilm formation and decreased attachment to fish fins and to other surfaces. Using genomic and proteomic approaches, we identified proteins secreted by the T9SS. We deleted ten genes encoding secreted proteins and characterized the virulence of mutants lacking individual or multiple secreted proteins. A mutant lacking two genes encoding predicted peptidases exhibited reduced virulence in rainbow trout, and mutants lacking a predicted cytolysin showed reduced virulence in zebrafish and rainbow trout. The results establish F. columnare strain MS-FC-4 as a genetically amenable model to identify virulence factors. This may aid development of measures to control columnaris disease and impact fish health and sustainable aquaculture. IMPORTANCE: Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish and is a major problem for aquaculture. Little is known regarding the virulence factors involved in this disease and control measures are inadequate. The type IX secretion system (T9SS) secretes many proteins and is required for virulence, but the secreted virulence factors are not known. We identified a strain of F. columnare (MS-FC-4) that is well suited for genetic manipulation. The components of the T9SS and the proteins secreted by this system were identified. Deletion of core T9SS genes eliminated virulence. Genes encoding ten secreted proteins were deleted. Deletion of two peptidase-encoding genes resulted in decreased virulence in rainbow trout, and deletion of a cytolysin-encoding gene resulted in decreased virulence in rainbow trout and zebrafish. Secreted peptidases and cytolysins are likely virulence factors and are targets for the development of control measures.
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23
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McKee LS, La Rosa SL, Westereng B, Eijsink VG, Pope PB, Larsbrink J. Polysaccharide degradation by the Bacteroidetes: mechanisms and nomenclature. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:559-581. [PMID: 34036727 DOI: 10.1111/1758-2229.12980] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/22/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
The Bacteroidetes phylum is renowned for its ability to degrade a wide range of complex carbohydrates, a trait that has enabled its dominance in many diverse environments. The best studied species inhabit the human gut microbiome and use polysaccharide utilization loci (PULs), discrete genetic structures that encode proteins involved in the sensing, binding, deconstruction, and import of target glycans. In many environmental species, polysaccharide degradation is tightly coupled to the phylum-exclusive type IX secretion system (T9SS), which is used for the secretion of certain enzymes and is linked to gliding motility. In addition, within specific species these two adaptive systems (PULs and T9SS) are intertwined, with PUL-encoded enzymes being secreted by the T9SS. Here, we discuss the most noteworthy PUL and non-PUL mechanisms that confer specific and rapid polysaccharide degradation capabilities to the Bacteroidetes in a range of environments. We also acknowledge that the literature showcasing examples of PULs is rapidly expanding and developing a set of assumptions that can be hard to track back to original findings. Therefore, we present a simple universal description of conserved PUL functions and how they are determined, while proposing a common nomenclature describing PULs and their components, to simplify discussion and understanding of PUL systems.
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Affiliation(s)
- Lauren S McKee
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, 106 91, Sweden
- Wallenberg Wood Science Center, Stockholm, 100 44, Sweden
| | | | - Bjørge Westereng
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Vincent G Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Phillip B Pope
- Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Johan Larsbrink
- Wallenberg Wood Science Center, Stockholm, 100 44, Sweden
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, 412 96, Sweden
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24
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Okamoto-Shibayama K, Warita T, Kokubu E, Kita D, Kikuchi Y, Ishihara K. Role of Hyalin-like Protein in Gliding and Biofilm Formation by Capnocytophaga Ochracea. THE BULLETIN OF TOKYO DENTAL COLLEGE 2021; 62:89-98. [PMID: 33994426 DOI: 10.2209/tdcpublication.2020-0051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Capnocytophaga ochracea possesses a type-IX secretion system that exports proteins which have a gliding motility-associated C-terminal (CTD) domain. This system is found in several species of the Bacteroidetes phylum. Hyalin, a large protein encoded by Coch_0033 in C. ochracea ATCC 27872, has a CTD domain and is posited to be involved in quorum sensing according to the database of the Kyoto Encyclopedia of Genes and Genomes. This suggests that it plays a role in biofilm formation via interbacterial communication. The aim of this study was to investigate the potential role of the hyalin-like protein coded by the Coch_0033 gene in gliding and biofilm formation of C. ochracea. A hyalin-like protein-deficient mutant strain of C. ochracea, designated mutant WR-1, was constructed through insertion of the ermF-ermAM cassette into the target gene. The spreading feature at the edge of the colony was lost in the mutant strain. Crystal violet and confocal laser scanning microscopy revealed no difference between the quantity of biofilm organized by the mutant and that organized by the wild-type strain. These data suggest that the hyalin-like protein encoded by the Coch_0033 gene is indeed involved in C. ochracea gliding activity.
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Affiliation(s)
- Kazuko Okamoto-Shibayama
- Department of Microbiology, Tokyo Dental College.,Oral Health Science Center, Tokyo Dental College
| | | | - Eitoyo Kokubu
- Department of Microbiology, Tokyo Dental College.,Oral Health Science Center, Tokyo Dental College
| | - Daichi Kita
- Department of Periodontology, Tokyo Dental College
| | - Yuichiro Kikuchi
- Department of Microbiology, Tokyo Dental College.,Oral Health Science Center, Tokyo Dental College
| | - Kazuyuki Ishihara
- Department of Microbiology, Tokyo Dental College.,Oral Health Science Center, Tokyo Dental College
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25
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Lunar Silva I, Cascales E. Molecular Strategies Underlying Porphyromonas gingivalis Virulence. J Mol Biol 2021; 433:166836. [PMID: 33539891 DOI: 10.1016/j.jmb.2021.166836] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/15/2021] [Accepted: 01/15/2021] [Indexed: 02/07/2023]
Abstract
The anaerobic Gram-negative bacterium Porphyromonas gingivalis is considered the keystone of periodontitis diseases, a set of inflammatory conditions that affects the tissues surrounding the teeth. In the recent years, the major virulence factors exploited by P. gingivalis have been identified and characterized, including a cocktail of toxins, mainly proteases called gingipains, which promote gingival tissue invasion. These effectors use the Sec pathway to cross the inner membrane and are then recruited and transported across the outer membrane by the type IX secretion system (T9SS). In P. gingivalis, most secreted effectors are attached to anionic lipopolysaccharides (A-LPS), and hence form a virulence coat at the cell surface. P. gingivalis produces additional virulence factors to evade host immune responses, such as capsular polysaccharide, fimbriae and outer membrane vesicles. In addition to periodontitis, it is proposed that this broad repertoire of virulence factors enable P. gingivalis to be involved in diverse human diseases such as rheumatoid arthritis, and neurodegenerative, Alzheimer, and cardiovascular disorders. Here, we review the major virulence determinants of P. gingivalis and discuss future directions to better understand their mechanisms of action.
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Affiliation(s)
- Ignacio Lunar Silva
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
| | - Eric Cascales
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
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26
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Phulpoto IA, Hu B, Wang Y, Ndayisenga F, Li J, Yu Z. Effect of natural microbiome and culturable biosurfactants-producing bacterial consortia of freshwater lake on petroleum-hydrocarbon degradation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 751:141720. [PMID: 32882554 DOI: 10.1016/j.scitotenv.2020.141720] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Abstract
Freshwater lake ecosystem is a reservior of valuable microbial diversity. It needs to be explored for addressing key environmental issues like petroleum-hydrocarbon contamination. In this work, the microbial communities (pre and post enriched with petroleum-hydrocarbons) from different layers of freshwater lake, i.e. surface water, sediments and deepwater, were explored through metagenomic and culture-dependent approaches. A total of 41 bacterial phyla were retrieved from pre-enriched samples, which were significantly reduced in enriched samples where Proteobacteria were dominant (87% to 100%) followed by Bacteroidetes (7.37%) and Verrucomicrobia (3.06%). The most dominant hydrocarbon-degrading genera were extensively verified as Pseudomonas (48.65%), Acinetobacter (45.38%), Stenotrophomonas (3.16%) and Brevundimonas (2.07%) in surface water (S1WCC); Acinetobacter (62.46%), Aeromonas (10.7%), Sphingobacterium (5.20%) and Pseudomonas (4.23%) in sediment (S2MCC); and Acinetobacter (46.57%), Pseudomonas (13.10%), Comamonas (12.93%), Flavobacterium (12.18%) and Enterobacter (9.62%) in deep water (S4WCC). Additionally, the maximum biodegradation of petroleum-hydrocarbons (i.e. used engine oil or UEO) was achieved by microbiome of S2MCC (67.60 ± 0.08%) followed by S4WCC (59.70 ± 0.12%), whereas only 36.80 ± 0.10% degradation was achieved by S1WCC microbiome. On the other hand, UEO degradation by cultivable biosurfactant-producing single cultures such as Pseudomonas sp. S2WE, Pseudomonas sp. S2WG, Pseudomonas sp. S2MS, Ochrobactrum sp. S1MM and Bacillus nealsonii S2MT showed 31.10 ± 0.08% to 40.50 ± 0.11% biodegradation. Comparatively, the biodegradation efficiency was found higher (i.e. 42.20 ± 0.12% to 56.10 ± 0.12%) in each consortia comprising of two, three, four, and five bacterial cultures. Conclusively, the isolated culturable biosurfactants-producing bacterial consortium of freshwater lake demonstrated >80% contribution in the total petroleum-hydrocarbons degradation by the natural microbiome of the ecosystem.
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Affiliation(s)
- Irfan Ali Phulpoto
- College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China
| | - Bowen Hu
- College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China
| | - Yanfen Wang
- Yanshan Earth Critical Zone and Surface Fluxes Research Station, Chinese Academy of Sciences, No. 380 Huaibei Town, Huairou District, Beijing 101408, PR China
| | - Fabrice Ndayisenga
- College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China
| | - Jinmei Li
- College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China
| | - Zhisheng Yu
- College of Resources and Environment, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 100049, PR China.
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27
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Mukherjee S, Behera PK, Madhuprakash J. Efficient conversion of crystalline chitin to N-acetylglucosamine and N,N'-diacetylchitobiose by the enzyme cocktail produced by Paenibacillus sp. LS1. Carbohydr Polym 2020; 250:116889. [DOI: 10.1016/j.carbpol.2020.116889] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 12/20/2022]
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28
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Cooperative Interaction of Janthinobacterium sp. SLB01 and Flavobacterium sp. SLB02 in the Diseased Sponge Lubomirskia baicalensis. Int J Mol Sci 2020; 21:ijms21218128. [PMID: 33143227 PMCID: PMC7662799 DOI: 10.3390/ijms21218128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 11/17/2022] Open
Abstract
Endemic freshwater sponges (demosponges, Lubomirskiidae) dominate in Lake Baikal, Central Siberia, Russia. These sponges are multicellular filter-feeding animals that represent a complex consortium of many species of eukaryotes and prokaryotes. In recent years, mass disease and death of Lubomirskia baicalensis has been a significant problem in Lake Baikal. The etiology and ecology of these events remain unknown. Bacteria from the families Flavobacteriaceae and Oxalobacteraceae dominate the microbiomes of diseased sponges. Both species are opportunistic pathogens common in freshwater ecosystems. The aim of our study was to analyze the genomes of strains Janthinobacterium sp. SLB01 and Flavobacterium sp. SLB02, isolated from diseased sponges to identify the reasons for their joint dominance. Janthinobacterium sp. SLB01 attacks other cells using a type VI secretion system and suppresses gram-positive bacteria with violacein, and regulates its own activity via quorum sensing. It produces floc and strong biofilm by exopolysaccharide biosynthesis and PEP-CTERM/XrtA protein expression. Flavobacterium sp. SLB02 utilizes the fragments of cell walls produced by polysaccharides. These two strains have a marked difference in carbohydrate acquisition. We described a possible means of joint occupation of the ecological niche in the freshwater sponge microbial community. This study expands the understanding of the symbiotic relationship of microorganisms with freshwater Baikal sponges.
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29
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K S R, Varghese S, M S J. Sequence analysis and docking performance of extracellular chitinase from Bacillus pumilus MCB-7, a novel mangrove isolate. Enzyme Microb Technol 2020; 140:109624. [PMID: 32912684 DOI: 10.1016/j.enzmictec.2020.109624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/11/2020] [Indexed: 10/24/2022]
Abstract
Bacterial chitinases has a major role in chitinaceous waste management, biological control of pests and phytopathogens. In the present study, exochitinase gene ChitA encoding extracellular chitinase from the mangrove bacteria Bacillus pumilus MCB-07 was genetically characterized. Oligonucleotide primers specific to chitinase gene of Bacillus pumilus were designed and amplified by PCR. The purified PCR product was successfully cloned in pGEM-T vector and transformed into Escherichia coli DH5-α competent cells. Nucleotide sequence alignment of the chitinase gene revealed 96 % similarity whereas 94 % of the catalytic domain of 598 amino acids is conserved with protein family GH18 chitinases, which is a novel report for Bacillus pumilus. The insert also showed a number of substitutions (mutations) with other sp. of Bacillus which demonstrated that chitinase of Bacillus pumilus MCB-07 is a novel gene. Multiple sequence alignment of chitinase gene sequences and its predicted amino acid sequences were also evaluated and the sequence was deposited in GenBank with accession number KT966736.1. Homology modeling of the chitinase depicted the typical (α/β) 8 TIM barrel structure. Molecular docking of the protein was performed by Autodock 4.2.6 and the docked pocket contained Val 113, Met 114, Gln 99, Ala 75 and Cys 98 as the key binding residues. The molecular docking of Bacillus pumilus chitinase, revealed the involvement of a phenylalanine of the catalytic domain in the catalytic process of chitin to mono and oligomers of NAG. The amino acid exhibited both hydrophobic and hydrogen bond interactions of chitin molecules with phenylalanine.
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Affiliation(s)
- Rishad K S
- UniBiosys Biotech Research Labs, Cochin, Kerala, India
| | - Sherin Varghese
- School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India
| | - Jisha M S
- School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India.
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30
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Structural insights of the enzymes from the chitin utilization locus of Flavobacterium johnsoniae. Sci Rep 2020; 10:13775. [PMID: 32792608 PMCID: PMC7426924 DOI: 10.1038/s41598-020-70749-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/22/2020] [Indexed: 12/17/2022] Open
Abstract
Chitin is one of the most abundant renewable organic materials found on earth. The chitin utilization locus in Flavobacterium johnsoniae, which encodes necessary proteins for complete enzymatic depolymerization of crystalline chitin, has recently been characterized but no detailed structural information on the enzymes was provided. Here we present protein structures of the F. johnsoniae chitobiase (FjGH20) and chitinase B (FjChiB). FjGH20 is a multi-domain enzyme with a helical domain not before observed in other chitobiases and a domain organization reminiscent of GH84 (β-N-acetylglucosaminidase) family members. The structure of FjChiB reveals that the protein lacks loops and regions associated with exo-acting activity in other chitinases and instead has a more solvent accessible substrate binding cleft, which is consistent with its endo-chitinase activity. Additionally, small angle X-ray scattering data were collected for the internal 70 kDa region that connects the N- and C-terminal chitinase domains of the unique 158 kDa multi-domain chitinase A (FjChiA). The resulting model of the molecular envelope supports bioinformatic predictions of the region comprising six domains, each with similarities to either Fn3-like or Ig-like domains. Taken together, the results provide insights into chitin utilization by F. johnsoniae and reveal structural diversity in bacterial chitin metabolism.
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31
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The Type IX Secretion System Is Required for Virulence of the Fish Pathogen Flavobacterium psychrophilum. Appl Environ Microbiol 2020; 86:AEM.00799-20. [PMID: 32532872 DOI: 10.1128/aem.00799-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/06/2020] [Indexed: 12/15/2022] Open
Abstract
Flavobacterium psychrophilum causes bacterial cold-water disease in wild and aquaculture-reared fish and is a major problem for salmonid aquaculture. The mechanisms responsible for cold-water disease are not known. It was recently demonstrated that the related fish pathogen, Flavobacterium columnare, requires a functional type IX protein secretion system (T9SS) to cause disease. T9SSs secrete cell surface adhesins, gliding motility proteins, peptidases, and other enzymes, any of which may be virulence factors. The F. psychrophilum genome has genes predicted to encode components of a T9SS. Here, we used a SacB-mediated gene deletion technique recently adapted for use in the Bacteroidetes to delete a core F. psychrophilum T9SS gene, gldN The ΔgldN mutant cells were deficient for secretion of many proteins in comparison to wild-type cells. Complementation of the mutant with wild-type gldN on a plasmid restored secretion. Compared to wild-type and complemented strains, the ΔgldN mutant was deficient in adhesion, gliding motility, and extracellular proteolytic and hemolytic activities. The ΔgldN mutant exhibited reduced virulence in rainbow trout and complementation restored virulence, suggesting that the T9SS plays an important role in the disease.IMPORTANCE Bacterial cold-water disease, caused by F. psychrophilum, is a major problem for salmonid aquaculture. Little is known regarding the virulence factors involved in this disease, and control measures are inadequate. A targeted gene deletion method was adapted to F. psychrophilum and used to demonstrate the importance of the T9SS in virulence. Proteins secreted by this system are likely virulence factors and targets for the development of control measures.
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Gorasia DG, Veith PD, Reynolds EC. The Type IX Secretion System: Advances in Structure, Function and Organisation. Microorganisms 2020; 8:microorganisms8081173. [PMID: 32752268 PMCID: PMC7463736 DOI: 10.3390/microorganisms8081173] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 12/24/2022] Open
Abstract
The type IX secretion system (T9SS) is specific to the Bacteroidetes phylum. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilises the T9SS to transport many proteins—including its gingipain virulence factors—across the outer membrane and attach them to the cell surface. Additionally, the T9SS is also required for gliding motility in motile organisms, such as Flavobacterium johnsoniae. At least nineteen proteins have been identified as components of the T9SS, including the three transcription regulators, PorX, PorY and SigP. Although the components are known, the overall organisation and the molecular mechanism of how the T9SS operates is largely unknown. This review focusses on the recent advances made in the structure, function, and organisation of the T9SS machinery to provide further insight into this highly novel secretion system.
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33
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Chernogor L, Klimenko E, Khanaev I, Belikov S. Microbiome analysis of healthy and diseased sponges Lubomirskia baicalensis by using cell cultures of primmorphs. PeerJ 2020; 8:e9080. [PMID: 32518718 PMCID: PMC7258933 DOI: 10.7717/peerj.9080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/07/2020] [Indexed: 01/01/2023] Open
Abstract
Endemic sponges (Demosponges, Lubomirskiidae) dominate the fauna of the littoral zone of Lake Baikal. These freshwater sponges live in symbiosis with diverse eukaryotes and prokaryotes, including chlorophyll-containing microalgae. Within the last 5 years, the incidence of sponge disease and mortality events in Lake Baikal has increased. The etiology and ecology of these events remain unknown, in part because of the lack of models to study sponge-microbe interactions. In this work, we tested the use of primmorph cell cultures of Lubomirskia baicalensis as a tool for investigating the microbiomes of sponges. We infected primmorphs, cultured in vitro, with samples from diseased sponges and observed, by microscopy, disease symptoms, including loss of green symbionts, associated with mass die-off events. Subsequent sequencing of 16S rRNA gene fragments revealed that the microbiome community of healthy sponge and primmorphs formed a group separate from the community of diseased sponges and infected primmorphs. This confirms the suitability of the primmorph cell culture as a model sponge system. We also discovered mass mortality of green symbionts (Chlorophyta) was associated with a shift in the microbial communities of sponges/primmorphs. Microbes in diseased sponges, and infected primmorphs, belonged mainly to the phyla Bacteroidetes and Proteobacteria and these families Flavobacteriaceae, Burkholderiaceae, and Moraxellaceae. Primmorphs cell culture may provide a model to study interactions between these bacteria and their host and elucidate the cause of mass mortality events.
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Affiliation(s)
| | | | - Igor Khanaev
- Limnological Institute of the SB RAS, Irkutsk, Russia
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Cultivable, Host-Specific Bacteroidetes Symbionts Exhibit Diverse Polysaccharolytic Strategies. Appl Environ Microbiol 2020; 86:AEM.00091-20. [PMID: 32060023 DOI: 10.1128/aem.00091-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Beneficial gut microbes can facilitate insect growth on diverse diets. The omnivorous American cockroach, Periplaneta americana (Insecta: Blattodea), thrives on a diet rich in plant polysaccharides and harbors a species-rich gut microbiota responsive to host diet. Bacteroidetes are among the most abundant taxa in P. americana and other cockroaches, based on cultivation-independent gut community profiling, and these potentially polysaccharolytic bacteria may contribute to host diet processing. Eleven Bacteroidetes isolates were cultivated from P. americana digestive tracts, and phylogenomic analyses suggest that they were new Bacteroides, Dysgonomonas, Paludibacter, and Parabacteroides species distinct from those previously isolated from other insects, humans, and environmental sources. In addition, complete genomes were generated for each isolate, and polysaccharide utilization loci (PULs) and several non-PUL-associated carbohydrate-active enzyme (CAZyme)-coding genes that putatively target starch, pectin, and/or cellulose were annotated in each of the isolate genomes. Type IX secretion system (T9SS)- and CAZyme-coding genes tagged with the corresponding T9SS recognition and export C-terminal domain were observed in some isolates, suggesting that these CAZymes were deployed via non-PUL outer membrane translocons. Additionally, single-substrate growth and enzymatic assays confirmed genomic predictions that a subset of the Bacteroides and Dysgonomonas isolates could degrade starch, pectin, and/or cellulose and grow in the presence of these substrates as a single sugar source. Plant polysaccharides enrich P. americana diets, and many of these gut isolates are well equipped to exploit host dietary inputs and potentially contribute to gut community and host nutrient accessibility.IMPORTANCE Gut microbes are increasingly being recognized as critical contributors to nutrient accessibility in animals. The globally distributed omnivorous American cockroach (Periplaneta americana) harbors many bacterial phyla (e.g., Bacteroidetes) that are abundant in vertebrates. P. americana thrives on a highly diverse plant-enriched diet, making this insect a rich potential source of uncharacterized polysaccharolytic bacteria. We have cultivated, completely sequenced, and functionally characterized several novel Bacteroidetes species that are endemic to the P. americana gut, and many of these isolates can degrade simple and complex polysaccharides. Cultivation and genomic characterization of these Bacteroidetes isolates further enable deeper insight into how these taxa participate in polysaccharide metabolism and, more broadly, how they affect animal health and development.
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Larsbrink J, McKee LS. Bacteroidetes bacteria in the soil: Glycan acquisition, enzyme secretion, and gliding motility. ADVANCES IN APPLIED MICROBIOLOGY 2020; 110:63-98. [PMID: 32386606 DOI: 10.1016/bs.aambs.2019.11.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The secretion of extracellular enzymes by soil microbes is rate-limiting in the recycling of biomass. Fungi and bacteria compete and collaborate for nutrients in the soil, with wide ranging ecological impacts. Within soil microbiota, the Bacteroidetes tend to be a dominant phylum, just like in human and animal intestines. The Bacteroidetes thrive because of their ability to secrete diverse arrays of carbohydrate-active enzymes (CAZymes) that target the highly varied glycans in the soil. Bacteroidetes use an energy-saving system of genomic organization, whereby most of their CAZymes are grouped into Polysaccharide Utilization Loci (PULs). These loci enable high level production of specific CAZymes only when their substrate glycans are abundant in the local environment. This gives the Bacteroidetes a clear advantage over other species in the competitive soil environment, further enhanced by the phylum-specific Type IX Secretion System (T9SS). The T9SS is highly effective at secreting CAZymes and/or tethering them to the cell surface, and is tightly coupled to the ability to rapidly glide over solid surfaces, a connection that promotes an active hunt for nutrition. Although the soil Bacteroidetes are less well studied than human gut symbionts, research is uncovering important biochemical and physiological phenomena. In this review, we summarize the state of the art on research into the CAZymes secreted by soil Bacteroidetes in the contexts of microbial soil ecology and the discovery of novel CAZymes for use in industrial biotechnology. We hope that this review will stimulate further investigations into the somewhat neglected enzymology of non-gut Bacteroidetes.
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Affiliation(s)
- Johan Larsbrink
- Wallenberg Wood Science Center, Gothenburg and Stockholm, Sweden; Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Lauren Sara McKee
- Wallenberg Wood Science Center, Gothenburg and Stockholm, Sweden; Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden.
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The Carboxy-Terminal Region of Flavobacterium johnsoniae SprB Facilitates Its Secretion by the Type IX Secretion System and Propulsion by the Gliding Motility Machinery. J Bacteriol 2019; 201:JB.00218-19. [PMID: 31262839 DOI: 10.1128/jb.00218-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/26/2019] [Indexed: 12/18/2022] Open
Abstract
Flavobacterium johnsoniae SprB moves rapidly along the cell surface, resulting in gliding motility. SprB secretion requires the type IX secretion system (T9SS). Proteins secreted by the T9SS typically have conserved C-terminal domains (CTDs) belonging to the type A CTD or type B CTD family. Attachment of 70- to 100-amino-acid type A CTDs to a foreign protein allows its secretion. Type B CTDs are common but have received little attention. Secretion of the foreign protein superfolder green fluorescent protein (sfGFP) fused to regions spanning the SprB type B CTD (sfGFP-CTDSprB) was analyzed. CTDs of 218 amino acids or longer resulted in secretion of sfGFP, whereas a 149-amino-acid region did not. Some sfGFP was secreted in soluble form, whereas the rest was attached on the cell surface. Surface-attached sfGFP was rapidly propelled along the cell, suggesting productive interaction with the motility machinery. This did not result in rapid cell movement, which apparently requires additional regions of SprB. Secretion of sfGFP-CTDSprB required coexpression with sprF, which lies downstream of sprB SprF is similar in sequence to Porphyromonas gingivalis PorP. Most F. johnsoniae genes encoding proteins with type B CTDs lie immediately upstream of porP/sprF-like genes. sfGFP was fused to the type B CTD from one such protein (Fjoh_3952). This resulted in secretion of sfGFP only when it was coexpressed with its cognate PorP/SprF-like protein. These results highlight the need for extended regions of type B CTDs and for coexpression with the appropriate PorP/SprF-like protein for efficient secretion and cell surface localization of cargo proteins.IMPORTANCE The F. johnsoniae gliding motility adhesin SprB is delivered to the cell surface by the type IX secretion system (T9SS) and is rapidly propelled along the cell by the motility machinery. How this 6,497-amino-acid protein interacts with the secretion and motility machines is not known. Fusion of the C-terminal 218 amino acids of SprB to a foreign cargo protein resulted in its secretion, attachment to the cell surface, and rapid movement by the motility machinery. Efficient secretion of SprB required coexpression with the outer membrane protein SprF. Secreted proteins that have sequence similarity to SprB in their C-terminal regions are common in the phylum Bacteroidetes and may have roles in adhesion, motility, and virulence.
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Silva SG, Blom J, Keller‐Costa T, Costa R. Comparative genomics reveals complex natural product biosynthesis capacities and carbon metabolism across host‐associated and free‐living
Aquimarina
(
Bacteroidetes, Flavobacteriaceae
) species. Environ Microbiol 2019; 21:4002-4019. [DOI: 10.1111/1462-2920.14747] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 07/12/2019] [Indexed: 01/26/2023]
Affiliation(s)
- Sandra G. Silva
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa Lisbon Portugal
| | - Jochen Blom
- Bioinformatics and Systems Biology Justus‐Liebig‐University Giessen 35392 Giessen Germany
| | - Tina Keller‐Costa
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa Lisbon Portugal
| | - Rodrigo Costa
- Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico (IST), Universidade de Lisboa Lisbon Portugal
- Centre of Marine Sciences (CCMAR) Algarve University 8005‐139 Faro Portugal
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Chen Z, Wang X, Ren X, Han W, Malhi KK, Ding C, Yu S. Riemerella anatipestifer GldM is required for bacterial gliding motility, protein secretion, and virulence. Vet Res 2019; 50:43. [PMID: 31164171 PMCID: PMC6549377 DOI: 10.1186/s13567-019-0660-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 04/12/2019] [Indexed: 12/02/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Genetic analyses suggest that this pathogen has a novel protein secretion system, known as the “type IX secretion system” (T9SS). We previously reported that deletion of the AS87_RS08465 gene significantly reduced the bacterial virulence of the R. anatipestifer strain Yb2, but the mechanism remained unclear. The AS87_RS08465 gene is predicted to encode the gliding motility protein GldM (GldM) protein, a key component of the T9SS complex. In this study, Western blotting analysis demonstrated that R. anatipestifer GldM was localized to the cytomembrane. Further study revealed that the adhesion and invasion capacities of the mutant strain RA2281 (designated Yb2ΔgldM) in Vero cells and the bacterial loads in the blood of infected ducks were significantly reduced. RNA-Seq and PCR analyses showed that six genes were upregulated and five genes were downregulated in the mutant strain Yb2ΔgldM and that these genes were mainly involved in the secretion of proteins. Yb2ΔgldM was also found to be defective in gliding motility and protein secretion. Liquid chromatography–tandem mass spectrometry analysis revealed that nine of the proteins had a conserved T9SS C-terminal domain and were differentially secreted by Yb2ΔgldM compared to Yb2. The complementation strain cYb2ΔgldM recovered the adhesion and invasion capacities in Vero cells and the bacterial loads in the blood of infected ducks as well as the bacterial gliding motility and most protein secretion in the mutant strain Yb2ΔgldM to the levels of the wild-type strain Yb2. Taken together, these results indicate that R. anatipestifer GldM is associated with T9SS and is important in bacterial virulence.
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Affiliation(s)
- Zongchao Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaolan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaomei Ren
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Wenlong Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Kanwar Kumar Malhi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China. .,Jiangsu Agri-animal Husbandry Vocational College, Veterinary Bio-pharmaceutical, Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Taizhou, Jiangsu, China.
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39
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Characterizing a Halo-Tolerant GH10 Xylanase from Roseithermus sacchariphilus Strain RA and Its CBM-Truncated Variant. Int J Mol Sci 2019; 20:ijms20092284. [PMID: 31075847 PMCID: PMC6539836 DOI: 10.3390/ijms20092284] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/22/2019] [Accepted: 05/07/2019] [Indexed: 11/26/2022] Open
Abstract
A halo-thermophilic bacterium, Roseithermus sacchariphilus strain RA (previously known as Rhodothermaceae bacterium RA), was isolated from a hot spring in Langkawi, Malaysia. A complete genome analysis showed that the bacterium harbors 57 glycoside hydrolases (GHs), including a multi-domain xylanase (XynRA2). The full-length XynRA2 of 813 amino acids comprises a family 4_9 carbohydrate-binding module (CBM4_9), a family 10 glycoside hydrolase catalytic domain (GH10), and a C-terminal domain (CTD) for type IX secretion system (T9SS). This study aims to describe the biochemical properties of XynRA2 and the effects of CBM truncation on this xylanase. XynRA2 and its CBM-truncated variant (XynRA2ΔCBM) was expressed, purified, and characterized. The purified XynRA2 and XynRA2ΔCBM had an identical optimum temperature at 70 °C, but different optimum pHs of 8.5 and 6.0 respectively. Furthermore, XynRA2 retained 94% and 71% of activity at 4.0 M and 5.0 M NaCl respectively, whereas XynRA2ΔCBM showed a lower activity (79% and 54%). XynRA2 exhibited a turnover rate (kcat) of 24.8 s−1, but this was reduced by 40% for XynRA2ΔCBM. Both the xylanases hydrolyzed beechwood xylan predominantly into xylobiose, and oat-spelt xylan into a mixture of xylo-oligosaccharides (XOs). Collectively, this work suggested CBM4_9 of XynRA2 has a role in enzyme performance.
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40
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Comparative genome analysis provides novel insight into the interaction of Aquimarina sp. AD1, BL5 and AD10 with their macroalgal host. Mar Genomics 2019; 46:8-15. [PMID: 30852185 DOI: 10.1016/j.margen.2019.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 11/23/2022]
Abstract
The Aquimarina genus is widely distributed throughout the marine environment, however little is understood regarding its ecological role, particularly when in association with eukaryotic hosts. Here, we examine the genomes of two opportunistic pathogens, Aquimarina sp. AD1 and BL5, and a non-pathogenic strain Aquimarina sp. AD10, that were isolated from diseased individuals of the red alga Delisea pulchra. Each strain encodes multiple genes for the degradation of marine carbohydrates and vitamin biosynthesis. These traits are hypothesised to promote nutrient exchange between the Aquimarina strains and their algal host, facilitating a close symbiotic relationship. Moreover, each strain harbours the necessary genes for the assembly of a Type 9 Secretion System (T9SS) and the associated gliding motility apparatus. In addition to these common features, pathogenic strains AD1 and BL5, encode genes for the production of flexirubin type pigments and a number of unique non-ribosomal peptide synthesis (NRPS) gene clusters, suggesting a role for these uncharacterised traits in virulence. This study provides valuable insight into the potential ecological role of Aquimarina in the marine environment and the complex factors driving pathogenesis and symbiosis in this genus.
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41
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Hu D, Guo Y, Guo J, Wang Y, Pan Z, Xiao Y, Wang X, Hu S, Liu M, Li Z, Bi D, Zhou Z. Deletion of the Riemerella anatipestifer type IX secretion system gene sprA results in differential expression of outer membrane proteins and virulence. Avian Pathol 2019; 48:191-203. [PMID: 30640518 DOI: 10.1080/03079457.2019.1566594] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Riemerella anatipestifer (RA), the causative agent of infectious serositis that targets ducklings and other poultry, secretes protein via the type IX secretion system (T9SS). The proteins transported by T9SS are located on the bacterial cell surface or secreted into the extracellular milieu. In this study, a sprA deletion mutant was constructed encoding a core protein of T9SS to investigate its influence on outer membrane protein expression and its role in virulence. Compared with the wild-type RA-YM strain, the deletion mutant ΔsprA failed to digest gelatin, showed the same growth rate in the logarithmic phase and exhibited greater sensitivity to the bactericidal activity of duck sera, whereas the complemented strain restored these phenotypes. The outer membrane proteome of RA-YM and the ΔsprA mutant were analyzed by Tandem Mass Tags, which revealed 198 proteins with predicted localization to the cell envelope. Sixty-three of these proteins were differentially expressed in the outer membrane, with 43 up-regulated and 20 down-regulated. Among the twelve outer membrane proteins which were secreted by T9SS, four proteins were up-regulated and one protein was down-regulated. Animal experiments demonstrated that the median lethal dose of the mutant strain ΔsprA was about 500 times higher than that of the wild-type RA-YM strain, and bacterial loads in blood, brain, heart, liver and spleen of the ΔsprA-infected ducks were significantly reduced. Our results indicate that the SprA is a virulence-associated factor of RA, and its absence results in altered abundance of outer membrane proteins, and secretion disorders associated with some of the T9SS effector proteins.
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Affiliation(s)
- Di Hu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Yunqing Guo
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Jie Guo
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Ying Wang
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zhe Pan
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Yuncai Xiao
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Xiliang Wang
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Sishun Hu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Mei Liu
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zili Li
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Dingren Bi
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
| | - Zutao Zhou
- a State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China.,b Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine , Huazhong Agricultural University , Wuhan , People's Republic of China
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Abstract
ABSTRACT
Members of the phylum
Bacteroidetes
have many unique features, including gliding motility and the type IX protein secretion system (T9SS).
Bacteroidetes
gliding and T9SSs are common in, but apparently confined to, this phylum. Most, but not all, members of the phylum secrete proteins using the T9SS, and most also exhibit gliding motility. T9SSs secrete cell surface components of the gliding motility machinery and also secrete many extracellular or cell surface enzymes, adhesins, and virulence factors. The components of the T9SS are novel and are unrelated to those of other bacterial secretion systems. Proteins secreted by the T9SS rely on the Sec system to cross the cytoplasmic membrane, and they use the T9SS for delivery across the outer membrane. Secreted proteins typically have conserved C-terminal domains that target them to the T9SS. Some of the T9SS components were initially identified as proteins required for gliding motility. Gliding does not involve flagella or pili and instead relies on the rapid movement of motility adhesins, such as SprB, along the cell surface by the gliding motor. Contact of the adhesins with the substratum provides the traction that results in cell movement. SprB and other motility adhesins are delivered to the cell surface by the T9SS. Gliding and the T9SS appear to be intertwined, and components of the T9SS that span the cytoplasmic membrane may energize both gliding and protein secretion. The functions of the individual proteins in each process are the subject of ongoing investigations.
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Nishioka T, Marian M, Kobayashi I, Kobayashi Y, Yamamoto K, Tamaki H, Suga H, Shimizu M. Microbial basis of Fusarium wilt suppression by Allium cultivation. Sci Rep 2019; 9:1715. [PMID: 30737419 PMCID: PMC6368641 DOI: 10.1038/s41598-018-37559-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/10/2018] [Indexed: 11/22/2022] Open
Abstract
Crop rotation and intercropping with Allium plants suppresses Fusarium wilt in various crops. However, the mechanisms underlying this phenomenon have not been fully elucidated. This study was designed to assess the role of microorganisms inhabiting Allium rhizospheres and antifungal compounds produced by Allium roots in Fusarium wilt suppression by Allium cultivation. Suppression of cucumber Fusarium wilt and the pathogen multiplication by Allium (Welsh onion and/or onion)-cultivated soils were eliminated by heat treatment at 60 °C, whereas those by Welsh onion-root extract were lost at 40 °C. The addition of antibacterial antibiotics eliminated the suppressive effect of Welsh onion-cultivated soil on pathogen multiplication, suggesting the contribution of antagonistic gram-negative bacteria to the soil suppressiveness. The Illumina MiSeq sequencing of 16S rRNA gene amplicons revealed that genus Flavobacterium was the predominant group that preferentially accumulated in Allium rhizospheres. Flavobacterium species recovered from the rhizosphere soils of these Allium plants suppressed Fusarium wilt on cucumber seedlings. Furthermore, confocal laser scanning microscopy revealed that Flavobacterium isolates inhibited the multiplication of the pathogen in soil. Taken together, we infer that the accumulation of antagonistic Flavobacterium species plays a key role in Fusarium wilt suppression by Allium cultivation.
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Affiliation(s)
- Tomoki Nishioka
- The United Graduate school of Agricultural Science, Gifu University, Gifu, Japan
| | - Malek Marian
- The United Graduate school of Agricultural Science, Gifu University, Gifu, Japan
| | - Issei Kobayashi
- Center for Molecular Biology and Genetics, Mie University, Tsu, Mie, Japan
| | - Yuhko Kobayashi
- Center for Molecular Biology and Genetics, Mie University, Tsu, Mie, Japan
| | - Kyosuke Yamamoto
- Bioproduction Research Institute, National Institute of Advanced and Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Hideyuki Tamaki
- Bioproduction Research Institute, National Institute of Advanced and Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Haruhisa Suga
- Life Science Research Center, Gifu University, Gifu, Japan
| | - Masafumi Shimizu
- The United Graduate school of Agricultural Science, Gifu University, Gifu, Japan.
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Kondo Y, Sato K, Nagano K, Nishiguchi M, Hoshino T, Fujiwara T, Nakayama K. Involvement of PorK, a component of the type IX secretion system, in Prevotella melaninogenica pathogenicity. Microbiol Immunol 2018; 62:554-566. [PMID: 30028034 DOI: 10.1111/1348-0421.12638] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 12/27/2022]
Abstract
Prevotella melaninogenica is a gram-negative anaerobic commensal bacterium that resides in the human oral cavity and is isolated as a pathogen of suppurative diseases both inside and outside the mouth. However, little is known about the pathogenic factors of P. melaninogenica. The periodontal pathogens Porphyromonas gingivalis and Tanerella forsythia secrete virulence factors such as protease and bacterial cell surface proteins via a type IX secretion system (T9SS) that are involved in pathogenicity. P. melaninogenica also possesses all known orthologs of T9SS. In this study, a P. melaninogenica GAI 07411 mutant deficient in the orthologue of the T9SS-encoding gene, porK, was constructed. Hemagglutination and biofilm formation were decreased in the porK mutant. Furthermore, following growth on skim milk-containing medium, the diameters of the halos surrounding the porK mutant were smaller than those of the wild-type strain, suggesting a decrease in secretion of proteases outside the bacterium. To investigate this in detail, culture supernatants of wild-type and porK mutant strains were purified and compared by two-dimensional electrophoresis. In the mutant strain, fewer spots were detected, indicating fewer secreted proteins. In infection experiments, the mortality rate of mice inoculated with the porK mutant strain was significantly lower than in the wild-type strain. These results suggest that P. melaninogenica secretes potent virulence factors via the T9SS that contribute to its pathogenic ability.
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Affiliation(s)
- Yoshio Kondo
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Keiko Sato
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Keiji Nagano
- Department of Microbiology, School of Dentistry, Aichi Gakuin University 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Miyuki Nishiguchi
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Tomonori Hoshino
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Taku Fujiwara
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
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Naas AE, Solden LM, Norbeck AD, Brewer H, Hagen LH, Heggenes IM, McHardy AC, Mackie RI, Paša-Tolić L, Arntzen MØ, Eijsink VGH, Koropatkin NM, Hess M, Wrighton KC, Pope PB. "Candidatus Paraporphyromonas polyenzymogenes" encodes multi-modular cellulases linked to the type IX secretion system. MICROBIOME 2018; 6:44. [PMID: 29490697 PMCID: PMC5831590 DOI: 10.1186/s40168-018-0421-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/07/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND In nature, obligate herbivorous ruminants have a close symbiotic relationship with their gastrointestinal microbiome, which proficiently deconstructs plant biomass. Despite decades of research, lignocellulose degradation in the rumen has thus far been attributed to a limited number of culturable microorganisms. Here, we combine meta-omics and enzymology to identify and describe a novel Bacteroidetes family ("Candidatus MH11") composed entirely of uncultivated strains that are predominant in ruminants and only distantly related to previously characterized taxa. RESULTS The first metabolic reconstruction of Ca. MH11-affiliated genome bins, with a particular focus on the provisionally named "Candidatus Paraporphyromonas polyenzymogenes", illustrated their capacity to degrade various lignocellulosic substrates via comprehensive inventories of singular and multi-modular carbohydrate active enzymes (CAZymes). Closer examination revealed an absence of archetypical polysaccharide utilization loci found in human gut microbiota. Instead, we identified many multi-modular CAZymes putatively secreted via the Bacteroidetes-specific type IX secretion system (T9SS). This included cellulases with two or more catalytic domains, which are modular arrangements that are unique to Bacteroidetes species studied to date. Core metabolic proteins from Ca. P. polyenzymogenes were detected in metaproteomic data and were enriched in rumen-incubated plant biomass, indicating that active saccharification and fermentation of complex carbohydrates could be assigned to members of this novel family. Biochemical analysis of selected Ca. P. polyenzymogenes CAZymes further iterated the cellulolytic activity of this hitherto uncultured bacterium towards linear polymers, such as amorphous and crystalline cellulose as well as mixed linkage β-glucans. CONCLUSION We propose that Ca. P. polyenzymogene genotypes and other Ca. MH11 members actively degrade plant biomass in the rumen of cows, sheep and most likely other ruminants, utilizing singular and multi-domain catalytic CAZymes secreted through the T9SS. The discovery of a prominent role of multi-modular cellulases in the Gram-negative Bacteroidetes, together with similar findings for Gram-positive cellulosomal bacteria (Ruminococcus flavefaciens) and anaerobic fungi (Orpinomyces sp.), suggests that complex enzymes are essential and have evolved within all major cellulolytic dominions inherent to the rumen.
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Affiliation(s)
- A E Naas
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway
| | - L M Solden
- Department of Microbiology, The Ohio State University, Columbus, OH, 43201, USA
| | - A D Norbeck
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - H Brewer
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - L H Hagen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway
| | - I M Heggenes
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway
| | - A C McHardy
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Inhoffenstraβe 7, 38124, Braunschweig, Germany
| | - R I Mackie
- Institute for Genomic Biology and Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - L Paša-Tolić
- Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - M Ø Arntzen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway
| | - V G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway
| | - N M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - M Hess
- Department of Animal Science, University of California, Davis, CA, 95616, USA
| | - K C Wrighton
- Department of Microbiology, The Ohio State University, Columbus, OH, 43201, USA
| | - P B Pope
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Post Office Box 5003, 1432, Ås, Norway.
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Johnston JJ, Shrivastava A, McBride MJ. Untangling Flavobacterium johnsoniae Gliding Motility and Protein Secretion. J Bacteriol 2018; 200:e00362-17. [PMID: 29109184 PMCID: PMC5738736 DOI: 10.1128/jb.00362-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 10/26/2017] [Indexed: 12/28/2022] Open
Abstract
Flavobacterium johnsoniae exhibits rapid gliding motility over surfaces. At least 20 genes are involved in this process. Seven of these, gldK, gldL, gldM, gldN, sprA, sprE, and sprT, encode proteins of the type IX protein secretion system (T9SS). The T9SS is required for surface localization of the motility adhesins SprB and RemA, and for secretion of the soluble chitinase ChiA. Here, we demonstrate that the gliding motility proteins GldA, GldB, GldD, GldF, GldH, GldI, and GldJ are also essential for secretion. Cells with mutations in the genes encoding any of these seven proteins had normal levels of gldK mRNA but dramatically reduced levels of the GldK protein, which may explain the secretion defects of the motility mutants. GldJ is necessary for stable accumulation of GldK, and each mutant lacked the GldJ protein. F. johnsoniae cells that produced truncated GldJ, lacking eight to 13 amino acids from the C terminus, accumulated GldK but were deficient in gliding motility. SprB was secreted by these cells but was not propelled along their surfaces. This C-terminal region of GldJ is thus required for gliding motility but not for secretion. The identification of mutants that are defective for motility but competent for secretion begins to untangle the F. johnsoniae gliding motility machinery from the T9SS.IMPORTANCE Many members of the phylum Bacteroidetes secrete proteins using T9SSs. T9SSs appear to be confined to members of this phylum. Many of these bacteria also glide rapidly over surfaces using a motility machine that is also confined to the Bacteroidetes and appears to be intertwined with the T9SS. This study identifies F. johnsoniae proteins that are required for both T9SS function and gliding motility. It also provides an explanation for the link between secretion and gliding and identifies mutants with defects in motility but not secretion.
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Affiliation(s)
- Joseph J Johnston
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Abhishek Shrivastava
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Mark J McBride
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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Guo Y, Hu D, Guo J, Wang T, Xiao Y, Wang X, Li S, Liu M, Li Z, Bi D, Zhou Z. Riemerella anatipestifer Type IX Secretion System Is Required for Virulence and Gelatinase Secretion. Front Microbiol 2017; 8:2553. [PMID: 29312236 PMCID: PMC5742166 DOI: 10.3389/fmicb.2017.02553] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/08/2017] [Indexed: 11/16/2022] Open
Abstract
Riemerella anatipestifer (RA), a major causative agent of septicemia anserum exsudativa in domesticated ducklings, has a protein secretion system known as the type IX secretion system (T9SS). It is unknown whether the T9SS contributes to the virulence of RA through secretion of factors associated with pathogenesis. To answer this question, we constructed an RA mutant deficient in sprT, which encodes a core protein of the T9SS. Deletion of sprT yielded cells that failed to digest gelatin, an effect that was rescued via complementation by a plasmid encoding wild-type sprT. Complement-mediated killing was significantly increased in the deletion mutant, suggesting that proteins secreted by the T9SS are necessary for complement evasion in RA. Liquid chromatography-tandem mass spectrometry analysis revealed that RAYM_01812 and RAYM_04099 proteins containing a subtilisin-like serine protease domain and exhibiting extracellular gelatinase activity were secreted by the T9SS. Animal experiments demonstrated that the virulence of mutant strain ΔsprT strain was attenuated by 42,000-fold relative to wild-type RA-YM. Immunization with the ΔsprT protected ducks from challenge with RA-YM, suggesting that the former can be used as a live attenuated vaccine. These results indicate that the T9SS is functional in RA and contributes to its virulence by exporting key proteins. In addition, subtilisin-like serine proteases which are important virulence factors that interact with complement proteins may enable RA to evade immune surveillance in the avian innate immune system.
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Affiliation(s)
- Yunqing Guo
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Di Hu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jie Guo
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tao Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Xiliang Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Shaowen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Mei Liu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Dingren Bi
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
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The Type IX Secretion System Is Required for Virulence of the Fish Pathogen Flavobacterium columnare. Appl Environ Microbiol 2017; 83:AEM.01769-17. [PMID: 28939608 DOI: 10.1128/aem.01769-17] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 09/18/2017] [Indexed: 01/21/2023] Open
Abstract
Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes, adhesins, and proteins involved in gliding motility. The F. columnare genome has all of the genes needed to encode a T9SS. gldN, which encodes a core component of the T9SS, was deleted in wild-type strains of F. columnare The F. columnare ΔgldN mutants were deficient in the secretion of several extracellular proteins and lacked gliding motility. The ΔgldN mutants exhibited reduced virulence in zebrafish, channel catfish, and rainbow trout, and complementation restored virulence. PorV is required for the secretion of a subset of proteins targeted to the T9SS. An F. columnare ΔporV mutant retained gliding motility but exhibited reduced virulence. Cell-free spent media from exponentially growing cultures of wild-type and complemented strains caused rapid mortality, but spent media from ΔgldN and ΔporV mutants did not, suggesting that soluble toxins are secreted by the T9SS.IMPORTANCE Columnaris disease, caused by F. columnare, is a major problem for freshwater aquaculture. Little is known regarding the virulence factors produced by F. columnare, and control measures are limited. Analysis of targeted gene deletion mutants revealed the importance of the type IX protein secretion system (T9SS) and of secreted toxins in F. columnare virulence. T9SSs are common in members of the phylum Bacteroidetes and likely contribute to the virulence of other animal and human pathogens.
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49
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Pérez-Pascual D, Rochat T, Kerouault B, Gómez E, Neulat-Ripoll F, Henry C, Quillet E, Guijarro JA, Bernardet JF, Duchaud E. More Than Gliding: Involvement of GldD and GldG in the Virulence of Flavobacterium psychrophilum. Front Microbiol 2017; 8:2168. [PMID: 29163446 PMCID: PMC5682007 DOI: 10.3389/fmicb.2017.02168] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/23/2017] [Indexed: 12/17/2022] Open
Abstract
A fascinating characteristic of most members of the genus Flavobacterium is their ability to move over surfaces by gliding motility. Flavobacterium psychrophilum, an important pathogen of farmed salmonids worldwide, contains in its genome the 19 gld and spr genes shown to be required for gliding or spreading in Flavobacterium johnsoniae; however, their relative role in its lifestyle remains unknown. In order to address this issue, two spreading deficient mutants were produced as part of a Tn4351 mutant library in F. psychrophilum strain THCO2-90. The transposons were inserted in gldD and gldG genes. While the wild-type strain is proficient in adhesion, biofilm formation and displays strong proteolytic activity, both mutants lost these characteristics. Extracellular proteome comparisons revealed important modifications for both mutants, with a significant reduction of the amounts of proteins likely transported through the outer membrane by the Type IX secretion system, indicating that GldD and GldG proteins are required for an effective activity of this system. In addition, a significant decrease in virulence was observed using rainbow trout bath and injection infection models. Our results reveal additional roles of gldD and gldG genes that are likely of importance for the F. psychrophilum lifestyle, including virulence.
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Affiliation(s)
- David Pérez-Pascual
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Tatiana Rochat
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Brigitte Kerouault
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Esther Gómez
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | - Fabienne Neulat-Ripoll
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Celine Henry
- PAPPSO, Micalis Institute, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Edwige Quillet
- GABI, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Jose A Guijarro
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | - Jean F Bernardet
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
| | - Eric Duchaud
- Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, Université Paris-Saclay, Jouy-en-Josas, France
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50
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Veliz EA, Martínez-Hidalgo P, Hirsch AM. Chitinase-producing bacteria and their role in biocontrol. AIMS Microbiol 2017; 3:689-705. [PMID: 31294182 PMCID: PMC6604996 DOI: 10.3934/microbiol.2017.3.689] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/19/2017] [Indexed: 11/30/2022] Open
Abstract
Chitin is an important component of the exteriors of insects and fungi. Upon degradation of chitin by a number of organisms, severe damage and even death may occur in pathogens and pests whose external surfaces contain this polymer. Currently, chemical fungicides and insecticides are the major means of controlling these disease-causing agents. However, due to the potential harm that these chemicals cause to the environment and to human and animal health, new strategies are being developed to replace or reduce the use of fungal- and pest-killing compounds in agriculture. In this context, chitinolytic microorganisms are likely to play an important role as biocontrol agents and pathogen antagonists and may also function in the control of postharvest rot. In this review, we discuss the literature concerning chitin and the basic knowledge of chitin-degrading enzymes, and also describe the biocontrol effects of chitinolytic microorganisms and their potential use as more sustainable pesticides and fungicides in the field.
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Affiliation(s)
- Esteban A Veliz
- Department of Molecular Cell and Developmental Biology, Molecular Biology Institute, University of California, Los Angeles, 90095-1606, USA
| | | | - Ann M Hirsch
- Department of Molecular Cell and Developmental Biology, Molecular Biology Institute, University of California, Los Angeles, 90095-1606, USA
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