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Irby I, Broddrick JT. Microbial adaptation to spaceflight is correlated with bacteriophage-encoded functions. Nat Commun 2024; 15:3474. [PMID: 38750067 PMCID: PMC11096397 DOI: 10.1038/s41467-023-42104-w] [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: 02/25/2023] [Accepted: 09/27/2023] [Indexed: 05/18/2024] Open
Abstract
Evidence from the International Space Station suggests microbial populations are rapidly adapting to the spacecraft environment; however, the mechanism of this adaptation is not understood. Bacteriophages are prolific mediators of bacterial adaptation on Earth. Here we survey 245 genomes sequenced from bacterial strains isolated on the International Space Station for dormant (lysogenic) bacteriophages. Our analysis indicates phage-associated genes are significantly different between spaceflight strains and their terrestrial counterparts. In addition, we identify 283 complete prophages, those that could initiate bacterial lysis and infect additional hosts, of which 21% are novel. These prophage regions encode functions that correlate with increased persistence in extreme environments, such as spaceflight, to include antimicrobial resistance and virulence, DNA damage repair, and dormancy. Our results correlate microbial adaptation in spaceflight to bacteriophage-encoded functions that may impact human health in spaceflight.
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Affiliation(s)
- Iris Irby
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, CA, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jared T Broddrick
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, CA, USA.
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2
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Jalil K, Tahara YO, Miyata M. Visualization of Bacillus subtilis spore structure and germination using quick-freeze deep-etch electron microscopy. Microscopy (Oxf) 2024:dfae023. [PMID: 38819330 DOI: 10.1093/jmicro/dfae023] [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: 03/06/2024] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 06/01/2024] Open
Abstract
Bacterial spores, known for their complex and resilient structures, have been the focus of visualization using various methodologies. In this study, we applied quick-freeze and replica electron microscopy techniques, allowing observation of Bacillus subtilis spores in high-contrast and three-dimensional detail. This method facilitated visualization of the spore structure with enhanced resolution and provided new insights into the spores and their germination processes. We identified and described five distinct structures: (i) hair-like structures on the spore surface, (ii) spike formation on the surface of lysozyme-treated spores, (iii) the fractured appearance of the spore cortex during germination, (iv) potential connections between small vesicles and the core membrane and (v) the evolving surface structure of nascent vegetative cells during germination.
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Affiliation(s)
- Kiran Jalil
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Yuhei O Tahara
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
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3
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Iqbal S, Begum F. Identification and characterization of integrated prophages and CRISPR-Cas system in Bacillus subtilis RS10 genome. Braz J Microbiol 2024; 55:537-542. [PMID: 38216797 PMCID: PMC10920515 DOI: 10.1007/s42770-024-01249-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 01/04/2024] [Indexed: 01/14/2024] Open
Abstract
Bacteriophages have been extensively investigated due to their prominent role in the virulence and resistance of pathogenic bacteria. However, little attention has been given to the non-pathogenic Bacillus phages, and their role in the ecological bacteria genome is overlooked. In the present study, we characterized two Bacillus phages with a linear DNA genome of 33.6 kb with 44.83% GC contents and 129.3 kb with 34.70% GC contents. A total of 46 and 175 putative coding DNA sequences (CDS) were identified in prophage 1 (P1) and prophage 2 (P2), respectively, with no tRNA genes. Comparative genome sequence analysis revealed that P1 shares eight CDS with phage Jimmer 2 (NC-041976), and phage Osiris (NC-028969), and six with phage phi CT9441A (NC-029022). On the other hand, P2 showed high similarity with Bacill_SPbeta_NC_001884 and Bacillus phage phi 105. Further, genome analysis indicates several horizontal gene transfer events in both phages during the evolution process. In addition, we detected two CRISPR-Cas systems for the first time in B. subtilis. The identified CRISPR system consists of 24 and 25 direct repeats and integrase coding genes, while the cas gene which encodes Cas protein involved in the cleavage of a target sequence is missing. These findings will expand the current knowledge of soil phages as well as help to develop a new perspective for investigating more ecological phages to understand their role in bacterial communities and diversity.
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Affiliation(s)
- Sajid Iqbal
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan.
- Oujiang Laboratory (Zhejiang Laboratory for Regenerative Medicine, Vision and Brain Health), Wenzhou, 325000, China.
| | - Farida Begum
- Department of Biochemistry, Abdul Wali Khan University Mardan (AWKUM), Mardan, Pakistan
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4
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Dergham Y, Le Coq D, Bridier A, Sanchez-Vizuete P, Jbara H, Deschamps J, Hamze K, Yoshida KI, Noirot-Gros MF, Briandet R. Bacillus subtilis NDmed, a model strain for biofilm genetic studies. Biofilm 2023; 6:100152. [PMID: 37694162 PMCID: PMC10485040 DOI: 10.1016/j.bioflm.2023.100152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/20/2023] [Accepted: 08/27/2023] [Indexed: 09/12/2023] Open
Abstract
The Bacillus subtilis strain NDmed was isolated from an endoscope washer-disinfector in a medical environment. NDmed can form complex macrocolonies with highly wrinkled architectural structures on solid medium. In static liquid culture, it produces thick pellicles at the interface with air as well as remarkable highly protruding ''beanstalk-like'' submerged biofilm structures at the solid surface. Since these mucoid submerged structures are hyper-resistant to biocides, NDmed has the ability to protect pathogens embedded in mixed-species biofilms by sheltering them from the action of these agents. Additionally, this non-domesticated and highly biofilm forming strain has the propensity of being genetically manipulated. Due to all these properties, the NDmed strain becomes a valuable model for the study of B. subtilis biofilms. This review focuses on several studies performed with NDmed that have highlighted the sophisticated genetic dynamics at play during B. subtilis biofilm formation. Further studies in project using modern molecular tools of advanced technologies with this strain, will allow to deepen our knowledge on the emerging properties of multicellular bacterial life.
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Affiliation(s)
- Yasmine Dergham
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
- Lebanese University, Faculty of Science, 1003 Beirut, Lebanon
| | - Dominique Le Coq
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
- Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Arnaud Bridier
- Fougères Laboratory, Antibiotics, Biocides, Residues and Resistance Unit, Anses, 35300, Fougères, France
| | - Pilar Sanchez-Vizuete
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Hadi Jbara
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Julien Deschamps
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Kassem Hamze
- Lebanese University, Faculty of Science, 1003 Beirut, Lebanon
| | - Ken-ichi Yoshida
- Department of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | | | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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5
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Douillard FP, Portinha IM, Derman Y, Woudstra C, Mäklin T, Dorner MB, Korkeala H, Henriques AO, Lindström M. A Novel Prophage-like Insertion Element within yabG Triggers Early Entry into Sporulation in Clostridium botulinum. Viruses 2023; 15:2431. [PMID: 38140671 PMCID: PMC10747680 DOI: 10.3390/v15122431] [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: 05/25/2023] [Revised: 12/12/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Sporulation is a finely regulated morphogenetic program important in the ecology and epidemiology of Clostridium botulinum. Exogenous elements disrupting sporulation-associated genes contribute to sporulation regulation and introduce diversity in the generally conserved sporulation programs of endospore formers. We identified a novel prophage-like DNA segment, termed the yin element, inserted within yabG, encoding a sporulation-specific cysteine protease, in an environmental isolate of C. botulinum. Bioinformatic analysis revealed that the genetic structure of the yin element resembles previously reported mobile intervening elements associated with sporulation genes. Within a pure C. botulinum culture, we observed two subpopulations of cells with the yin element either integrated into the yabG locus or excised as a circular DNA molecule. The dynamics between the two observed conformations of the yin element was growth-phase dependent and likely mediated by recombination events. The yin element was not required for sporulation by C. botulinum but triggered an earlier entry into sporulation than in a related isolate lacking this element. So far, the yin element has not been found in any other C. botulinum strains or other endospore-forming species. It remains to be demonstrated what kind of competitive edge it provides for C. botulinum survival and persistence.
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Affiliation(s)
- François P. Douillard
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
| | - Inês Martins Portinha
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
| | - Yağmur Derman
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
| | - Cédric Woudstra
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
| | - Tommi Mäklin
- Department of Mathematics and Statistics, Faculty of Science, University of Helsinki, 00560 Helsinki, Finland;
| | - Martin B. Dorner
- Centre for Biological Threats and Special Pathogens, ZBS3—Biological Toxins, Robert Koch Institute, 13353 Berlin, Germany;
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
| | - Adriano O. Henriques
- Institute of Chemical and Biological Technology, NOVA University Lisbon, 2780-157 Oeiras, Portugal;
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland; (F.P.D.); (I.M.P.); (Y.D.); (C.W.); (H.K.)
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6
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Kohm K, Jalomo-Khayrova E, Krüger A, Basu S, Steinchen W, Bange G, Frunzke J, Hertel R, Commichau F, Czech L. Structural and functional characterization of MrpR, the master repressor of the Bacillus subtilis prophage SPβ. Nucleic Acids Res 2023; 51:9452-9474. [PMID: 37602373 PMCID: PMC10516654 DOI: 10.1093/nar/gkad675] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/11/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
Prophages control their lifestyle to either be maintained within the host genome or enter the lytic cycle. Bacillus subtilis contains the SPβ prophage whose lysogenic state depends on the MrpR (YopR) protein, a key component of the lysis-lysogeny decision system. Using a historic B. subtilis strain harboring the heat-sensitive SPβ c2 mutant, we demonstrate that the lytic cycle of SPβ c2 can be induced by heat due to a single nucleotide exchange in the mrpR gene, rendering the encoded MrpRG136E protein temperature-sensitive. Structural characterization revealed that MrpR is a DNA-binding protein resembling the overall fold of tyrosine recombinases. MrpR has lost its recombinase function and the G136E exchange impairs its higher-order structure and DNA binding activity. Genome-wide profiling of MrpR binding revealed its association with the previously identified SPbeta repeated element (SPBRE) in the SPβ genome. MrpR functions as a master repressor of SPβ that binds to this conserved element to maintain lysogeny. The heat-inducible excision of the SPβ c2 mutant remains reliant on the serine recombinase SprA. A suppressor mutant analysis identified a previously unknown component of the lysis-lysogeny management system that is crucial for the induction of the lytic cycle of SPβ.
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Affiliation(s)
- Katharina Kohm
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Ekaterina Jalomo-Khayrova
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Aileen Krüger
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Syamantak Basu
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Wieland Steinchen
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
- Max-Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Laura Czech
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
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7
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Nakaya Y, Uchiike M, Hattori M, Moriyama M, Abe K, Kim E, Eichenberger P, Imamura D, Sato T. Identification of CgeA as a glycoprotein that anchors polysaccharides to the spore surface in Bacillus subtilis. Mol Microbiol 2023; 120:384-396. [PMID: 37485949 DOI: 10.1111/mmi.15126] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023]
Abstract
The Bacillus subtilis spore is composed of a core, containing chromosomal DNA, surrounded by a cortex layer made of peptidoglycan, and a coat composed of concentric proteinaceous layers. A polysaccharide layer is added to the spore surface, and likely anchored to the crust, the coat outermost layer. However, the identity of the coat protein(s) to which the spore polysaccharides (SPS) are attached is uncertain. First, we showed that the crust proteins CotVWXYZ and CgeA were all contained in the peeled SPS layer obtained from a strain missing CotE, the outer coat morphogenetic protein, suggesting that the SPS is indeed bound to at least one of the spore surface proteins. Second, CgeA is known to be located at the most downstream position in the crust assembly pathway. An analysis of truncated variants of CgeA suggested that its N-terminal half is required for localization to the spore surface, while its C-terminal half is necessary for SPS addition. Third, an amino acid substitution strategy revealed that SPS was anchored at threonine 112 (T112), which constitutes a probable O-glycosylation site on CgeA. Our results indicated that CgeA is a glycoprotein required to initiate SPS assembly and serves as an anchor protein linking the crust and SPS layers.
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Affiliation(s)
- Yusei Nakaya
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Miu Uchiike
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Mayuko Hattori
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Momoka Moriyama
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Kimihiro Abe
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
| | - Ella Kim
- Department of Biology, New York University, New York, New York, USA
| | | | - Daisuke Imamura
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Tsutomu Sato
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
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8
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Hamiot A, Lemy C, Krzewinski F, Faille C, Dubois T. Sporulation conditions influence the surface and adhesion properties of Bacillus subtilis spores. Front Microbiol 2023; 14:1219581. [PMID: 37720141 PMCID: PMC10502511 DOI: 10.3389/fmicb.2023.1219581] [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: 05/23/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Spore-forming bacteria of the Bacillus subtilis group are responsible for recurrent contamination of processing lines in the food industry which can lead to food spoilage. The persistence of B. subtilis would be due to the high resistance of spores to extreme environmental condition and their propensity to contaminate surfaces. While it is well known that sporulation conditions modulate spore resistance properties, little is known about their effect on surface and adhesion properties. Here, we studied the impact of 13 sporulation conditions on the surface and adhesion properties of B. subtilis 168 spores. We showed that Ca2+ or Mg2+ depletion, lower oxygen availability, acidic pH as well as oxidative stresses during sporulation lead to the release of more hydrophobic and adherent spores. The consequences of these sporulation conditions on crust composition in carbohydrates and proteins were also evaluated. The crust glycans of spores produced in a sporulation medium depleted in Ca2+ or Mg2+ or oxygen-limited conditions were impaired and contained lower amounts of rhamnose and legionaminic acid. In addition, we showed that lower oxygen availability or addition of hydrogen peroxide during sporulation decreases the relative amount of two crust proteins (CgeA and CotY) and the changes observed in these conditions could be due to transcriptional repression of genes involved in crust synthesis in late stationary phase. The fact that sporulation conditions affect the ease with which spores can contaminate surfaces could explain the frequent and recurrent presence of B. subtilis spores in food processing lines.
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Affiliation(s)
- Audrey Hamiot
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Christelle Lemy
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Frederic Krzewinski
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Christine Faille
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Thomas Dubois
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
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9
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Luthe T, Kever L, Thormann K, Frunzke J. Bacterial multicellular behavior in antiviral defense. Curr Opin Microbiol 2023; 74:102314. [PMID: 37030144 DOI: 10.1016/j.mib.2023.102314] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 04/08/2023]
Abstract
Multicellular behavior benefits seemingly simple organisms such as bacteria, by improving nutrient uptake, resistance to stresses, or by providing advantages in predatory interactions. Several recent studies have shown that this also extends to the defense against bacteriophages, which are omnipresent in almost all habitats. In this review, we summarize strategies conferring protection against phage infection at the multicellular level, covering secretion of small antiphage molecules or membrane vesicles, the role of quorum sensing in phage defense, the development of transient phage resistance, and the impact of biofilm components and architecture. Recent studies focusing on these topics push the boundaries of our understanding of the bacterial immune system and set the ground for an appreciation of bacterial multicellular behavior in antiviral defense.
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10
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Tang X, Zhong L, Tang L, Fan C, Zhang B, Wang M, Dong H, Zhou C, Rensing C, Zhou S, Zeng G. Lysogenic bacteriophages encoding arsenic resistance determinants promote bacterial community adaptation to arsenic toxicity. THE ISME JOURNAL 2023:10.1038/s41396-023-01425-w. [PMID: 37161002 DOI: 10.1038/s41396-023-01425-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/11/2023]
Abstract
Emerging evidence from genomics gives us a glimpse into the potential contribution of lysogenic bacteriophages (phages) to the environmental adaptability of their hosts. However, it is challenging to quantify this kind of contribution due to the lack of appropriate genetic markers and the associated controllable environmental factors. Here, based on the unique transformable nature of arsenic (the controllable environmental factor), a series of flooding microcosms was established to investigate the contribution of arsM-bearing lysogenic phages to their hosts' adaptation to trivalent arsenic [As(III)] toxicity, where arsM is the marker gene associated with microbial As(III) detoxification. In the 15-day flooding period, the concentration of As(III) was significantly increased, and this elevated As(III) toxicity visibly inhibited the bacterial population, but the latter quickly adapted to As(III) toxicity. During the flooding period, some lysogenic phages re-infected new hosts after an early burst, while others persistently followed the productive cycle (i.e., lytic cycle). The unique phage-host interplay contributed to the rapid spread of arsM among soil microbiota, enabling the quick recovery of the bacterial community. Moreover, the higher abundance of arsM imparted a greater arsenic methylation capability to soil microbiota. Collectively, this study provides experimental evidence for lysogenic phages assisting their hosts in adapting to an extreme environment, which highlights the ecological perspectives on lysogenic phage-host mutualism.
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Affiliation(s)
- Xiang Tang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Linrui Zhong
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Lin Tang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Changzheng Fan
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China.
| | - Baowei Zhang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Mier Wang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Haoran Dong
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Chengyun Zhou
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, P. R. China.
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11
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"French Phage Network" Annual Conference-Seventh Meeting Report. Viruses 2023; 15:v15020495. [PMID: 36851708 PMCID: PMC9966839 DOI: 10.3390/v15020495] [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: 02/02/2023] [Revised: 02/08/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023] Open
Abstract
The French Phage Network (Phages.fr) has continuously grown since its foundation, eight years ago. The annual conference, held at the Institut Pasteur in Paris, attracted 164 participants from the 11th to the 13th of October 2022. Researchers from academic laboratories, hospitals and private companies shared their ongoing projects and breakthroughs in the very institute where Felix d'Hérelle developed phage therapy over a century ago. The conference was divided into four thematic sessions, each opened by a keynote lecture: "Interaction between phages, mobile genetic elements and bacterial immune system," "Ecology and evolution of phage-bacteria interactions," "Molecular interplay between phages and their hosts" and "Therapeutic and biotechnological applications of phages." A total of 32 talks and 33 posters were presented during the conference.
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12
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Floccari VA, Dragoš A. Host control by SPβ phage regulatory switch as potential manipulation strategy. Curr Opin Microbiol 2023; 71:102260. [PMID: 36580707 DOI: 10.1016/j.mib.2022.102260] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 12/01/2022] [Accepted: 12/08/2022] [Indexed: 12/28/2022]
Abstract
The interaction between temperate phages and their bacterial hosts has always been one of the most controversial in nature. As genetic parasites, phages need their hosts to propagate, while the host may take advantage of the genetic arsenal carried in the phage genome. This intriguing host-parasite interplay with an evident mutualistic implication could be challenged by recent discoveries of alternative phage lifestyles and regulatory systems that seem to support a manipulative strategy pursued by the phage. Through two fascinating novel mechanisms concerning the active lysogeny and a phage-encoded quorum sensing system, referred as 'Arbitrium', employed by SPβ-like phages of Bacilli, we propose the parasite manipulation as ecological relationship between certain temperate phages and bacteria.
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Affiliation(s)
- Valentina A Floccari
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Anna Dragoš
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
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13
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Butala M, Dragoš A. Unique relationships between phages and endospore-forming hosts. Trends Microbiol 2022; 31:498-510. [PMID: 36535834 DOI: 10.1016/j.tim.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022]
Abstract
As part of their survival strategy under harsh environmental conditions, endospore-forming bacteria can trigger a sporulation developmental program. Although the regulatory cascades that precisely control the transformation of vegetative bacteria into mother cells and resilient spores have been described in detail, less is known about how bacteriophages that prey on endospore-formers exploit sporulation. Herein, we argue that phages infecting these bacteria have evolved several specific molecular mechanisms, not yet known in other bacteria, that manifest from the phage-driven alliance to negative effects on the host. We anticipate that the relationships between phages and endospore-formers outlined here will inspire studies on phage ecology and evolution, and could facilitate important advances in the development of phage therapies against pathogenic spore-formers.
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Affiliation(s)
- Matej Butala
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Anna Dragoš
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
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14
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Ventroux M, Noirot-Gros MF. Prophage-encoded small protein YqaH counteracts the activities of the replication initiator DnaA in Bacillus subtilis. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36748575 DOI: 10.1099/mic.0.001268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Bacterial genomes harbour cryptic prophages that are mostly transcriptionally silent with many unannotated genes. Still, cryptic prophages may contribute to their host fitness and phenotypes. In Bacillus subtilis, the yqaF-yqaN operon belongs to the prophage element skin, and is tightly repressed by the Xre-like repressor SknR. This operon contains several small ORFs (smORFs) potentially encoding small-sized proteins. The smORF-encoded peptide YqaH was previously reported to bind to the replication initiator DnaA. Here, using a yeast two-hybrid assay, we found that YqaH binds to the DNA binding domain IV of DnaA and interacts with Spo0A, a master regulator of sporulation. We isolated single amino acid substitutions in YqaH that abolished the interaction with DnaA but not with Spo0A. Then, using a plasmid-based inducible system to overexpress yqaH WT and mutant derivatives, we studied in B. subtilis the phenotypes associated with the specific loss-of-interaction with DnaA (DnaA_LOI). We found that expression of yqaH carrying DnaA_LOI mutations abolished the deleterious effects of yqaH WT expression on chromosome segregation, replication initiation and DnaA-regulated transcription. When YqaH was induced after vegetative growth, DnaA_LOI mutations abolished the drastic effects of YqaH WT on sporulation and biofilm formation. Thus, YqaH inhibits replication, sporulation and biofilm formation mainly by antagonizing DnaA in a manner that is independent of the cell cycle checkpoint Sda.
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Affiliation(s)
- Magali Ventroux
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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15
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Kin Discrimination Modifies Strain Distribution, Spatial Segregation, and Incorporation of Extracellular Matrix Polysaccharide Mutants of Bacillus subtilis Strains into Mixed Floating Biofilms. Appl Environ Microbiol 2022; 88:e0087122. [PMID: 36094206 PMCID: PMC9499035 DOI: 10.1128/aem.00871-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microorganisms in nature form multicellular groups called biofilms. In biofilms, bacteria embedded in the extracellular matrix (ECM) interact intensely due to their proximity. Most studies have investigated genetically homogeneous biofilms, leaving a gap in knowledge on genetically heterogeneous biofilms. Recent insights show that a Gram-positive model bacterium, Bacillus subtilis, discriminates between strains of high (kin) and low (nonkin) genetic similarity, reflected in merging (kin) and boundaries (nonkin) between swarms. However, it is unclear how kinship between interacting strains affects their fitness, the genotype assortment, and incorporation of the mutant lacking the main structural ECM polysaccharide (EpsA-O) into floating biofilms (pellicles). We cultivated Bacillus subtilis strains as mixtures of isogenic, kin, and nonkin strain combinations in the biofilm-promoting minimal medium under static conditions, allowing them to form pellicles. We show that in nonkin pellicles, the dominant strain strongly reduced the frequency of the other strain. Segregation of nonkin mixtures in pellicles increased and invasion of nonkin EpsA-O-deficient mutants into pellicles decreased compared to kin and isogenic floating biofilms. Kin and isogenic strains had comparable relative frequencies in pellicles and showed more homogenous cell mixing. Overall, our results emphasize kin discrimination as a social behavior that shapes strain distribution, spatial segregation, and ECM mutant ability to incorporate into genetically heterogenous biofilms of B. subtilis. IMPORTANCE Biofilm communities have beneficial and harmful effects on human societies in natural, medical, and industrial environments. Bacillus subtilis is a biotechnologically important bacterium that serves as a model for studying biofilms. Recent studies have shown that this species engages in kin discriminatory behavior during swarming, which may have implications for community assembly, thus being of fundamental importance. Effects of kin discrimination on fitness, genotype segregation, and success of extracellular matrix (ECM) polysaccharide (EpsA-O) mutant invasion into biofilms are not well understood. We provide evidence that kin discrimination depends on the antagonism of the dominant strain against nonkin by using environmental strains with determined kin types and integrated fluorescent reporters. Moreover, this antagonism has important implications for genotype segregation and for when the bacteria are mixed with ECM producers. The work advances the understanding of kin-discrimination-dependent bacterial sociality in biofilms and its role in the assembly of multicellular groups.
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16
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Abe K, Kato H, Hasegawa Y, Yamamoto T, Nomura N, Obana N. Visualization and characterization of spore morphogenesis in Paenibacillus polymyxa ATCC39564. J GEN APPL MICROBIOL 2022; 68:79-86. [PMID: 35418538 DOI: 10.2323/jgam.2021.10.006] [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: 11/03/2022]
Abstract
Paenibacillus polymyxa is a spore-forming Gram-positive bacterial species. Both its sporulation process and the spore properties are poorly understood. Here, we investigated sporulation in P. polymyxa ATCC39564. When cultured at 37℃ for 24 h in sporulation medium, more than 80% of the total cells in the culture were spores. Time-lapse imaging revealed that cellular morphological changes during sporulation of P. polymyxa were highly similar to those of B. subtilis. We demonstrated that genetic deletion of spo0A, sigE, sigF, sigG, or sigK, which are highly conserved transcriptional regulators in spore forming bacteria, abolished spore formation. In P. polymyxa, spo0A was required for cell growth in sporulation medium, as well as for the initiation of sporulation. The sigE and sigF mutants formed abnormal multiple asymmetric septa during the early stage of sporulation. The sigG and sigK mutants formed forespores in the sporangium, but they did not become mature. Moreover, fluorescence reporter analysis confirmed compartment-specific gene expression of spoIID and spoVFA in the mother cell and spoIIQ and sspF in the forespore. Transmission electron microscopy imaging revealed that P. polymyxa produces multilayered endospores but lacking a balloon-shaped exosporium. Our results indicate that spore morphogenesis is conserved between P. polymyxa and B. subtilis. However, P. polymyxa genomes lack many homologues encoding spore-coat proteins that are found in B. subtills, suggesting that there are differences in the spore coat composition and surface structure between P. polymyxa and B. subtilis.
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Affiliation(s)
- Kimihiro Abe
- Faculty of Life and Environmental Sciences, University of Tsukuba
| | - Hiroko Kato
- Gradudate School of Life and Environmental Sciences, University of Tsukuba
| | - Yuta Hasegawa
- Gradudate School of Life and Environmental Sciences, University of Tsukuba
| | - Tatsuya Yamamoto
- Faculty of Life and Environmental Sciences, University of Tsukuba
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba.,Microbiology Research Center for Sustainability, University of Tsukuba
| | - Nozomu Obana
- Microbiology Research Center for Sustainability, University of Tsukuba.,Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba
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17
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Suzuki S, Osada S, Imamura D, Sato T. New Bacillus subtilis vector, pSSβ, as genetic tool for site-specific integration and excision of cloned DNA, and prophage elimination. J GEN APPL MICROBIOL 2022; 68:71-78. [PMID: 35387911 DOI: 10.2323/jgam.2021.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Site-specific recombination (SSR) systems are employed in many genetic mobile elements, including temperate phages, for their integration and excision. Recently, they have also been used as tools for applications in fields ranging from basic to synthetic biology. SPβ is a temperate phage of the Siphoviridae family found in the laboratory standard Bacillus subtilis strain 168. SPβ encodes a serine-type recombinase, SprA, and recombination directionality factor (RDF), SprB. SprA catalyzes recombination between the attachment site of the phage, attP, and that of the host, attB, to integrate phage genome into the attB site of the host genome and generate attL and attR at both ends of the prophage genome. SprB works in conjunction with SprA and switches from attB/attP to attL/R recombination, which leads to excision of the prophage. In the present study, we took advantage of this highly efficient recombination system to develop a site-specific integration and excision plasmid vector, named pSSβ. It was constructed using pUC plasmid and the SSR system components, attP, sprA and sprB of SPβ. pSSβ was integrated into the attB site with a significantly high efficiency, and the resulting pSSβ integrated strain also easily eliminated pSSβ itself from the host genome by the induction of SprB expression with xylose. This report presents two applications using pSSβ that are particularly suitable for gene complementation experiments and for a curing system of SPβ prophage, that may serve as a model system for the removal of prophages in other bacteria.
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Affiliation(s)
- Shota Suzuki
- Research Center of Micro-Nano Technology, Hosei University.,Department of Life Science, College of Science, Rikkyo University
| | - Sachie Osada
- Department of Frontier Bioscience, Hosei University
| | | | - Tsutomu Sato
- Research Center of Micro-Nano Technology, Hosei University.,Department of Frontier Bioscience, Hosei University
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18
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Kohm K, Floccari VA, Lutz VT, Nordmann B, Mittelstädt C, Poehlein A, Dragoš A, Commichau FM, Hertel R. The Bacillus phage SPβ and its relatives: a temperate phage model system reveals new strains, species, prophage integration loci, conserved proteins and lysogeny management components. Environ Microbiol 2022; 24:2098-2118. [PMID: 35293111 DOI: 10.1111/1462-2920.15964] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/02/2022] [Indexed: 11/28/2022]
Abstract
The Bacillus phage SPβ has been known for about 50 years, but only a few strains are available. We isolated four new wild-type strains of the SPbeta species. Phage vB_BsuS-Goe14 introduces its prophage into the spoVK locus, previously not observed to be used by SPβ-like phages. Sequence data revealed the genome replication strategy and the genome packaging mode of SPβ-like phages. We extracted 55 SPβ-like prophages from public Bacillus genomes, thereby discovering three more integration loci and one additional type of integrase. The identified prophages resemble four new species clusters and three species orphans in the genus Spbetavirus. The determined core proteome of all SPβ-like prophages consists of 38 proteins. The integration cassette proved to be not conserved, even though, present in all strains. It consists of distinct integrases. Analysis of SPβ transcriptomes revealed three conserved genes, yopQ, yopR, and yokI, to be transcribed from a dormant prophage. While yopQ and yokI could be deleted from the prophage without activating the prophage, damaging of yopR led to a clear-plaque phenotype. Under the applied laboratory conditions, the yokI mutant showed an elevated virion release implying the YokI protein being a component of the arbitrium system.
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Affiliation(s)
- Katharina Kohm
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | | | - Veronika T Lutz
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark
| | - Birthe Nordmann
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University, Göttingen, 37077, Germany
| | - Carolin Mittelstädt
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University, Göttingen, 37077, Germany
| | - Anna Dragoš
- Biotechnical Faculty, University of Ljubljana, Ljubljana, 1000, Slovenia
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany
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19
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Sanchez-Vizuete P, Dergham Y, Bridier A, Deschamps J, Dervyn E, Hamze K, Aymerich S, Le Coq D, Briandet R. The coordinated population redistribution between Bacillus subtilis submerged biofilm and liquid-air pellicle. Biofilm 2022; 4:100065. [PMID: 35024609 PMCID: PMC8732777 DOI: 10.1016/j.bioflm.2021.100065] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 12/15/2022] Open
Abstract
Bacillus subtilis is a widely used bacterial model to decipher biofilm formation, genetic determinants and their regulation. For several years, studies were conducted on colonies or pellicles formed at the interface with air, but more recent works showed that non-domesticated strains were able to form thick and structured biofilms on submerged surfaces. Taking advantage of time-lapse confocal laser scanning microscopy, we monitored bacterial colonization on the surface and observed an unexpected biphasic submerged biofilm development. Cells adhering to the surface firstly form elongated chains before being suddenly fragmented and released as free motile cells in the medium. This switching coincided with an oxygen depletion in the well which preceded the formation of the pellicle at the liquid-air interface. Residual bacteria still associated with the solid surface at the bottom of the well started to express matrix genes under anaerobic metabolism to build the typical biofilm protruding structures.
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Affiliation(s)
- Pilar Sanchez-Vizuete
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Yasmine Dergham
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.,Faculty of Science, Lebanese University, 1003, Beirut, Lebanon
| | - Arnaud Bridier
- Fougères Laboratory, Antibiotics, Biocides, Residues and Resistance Unit, Anses, 35300, Fougères, France
| | - Julien Deschamps
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Etienne Dervyn
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Kassem Hamze
- Faculty of Science, Lebanese University, 1003, Beirut, Lebanon
| | - Stéphane Aymerich
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Dominique Le Coq
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.,Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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20
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Aframian N, Omer Bendori S, Kabel S, Guler P, Stokar-Avihail A, Manor E, Msaeed K, Lipsman V, Grinberg I, Mahagna A, Eldar A. Dormant phages communicate via arbitrium to control exit from lysogeny. Nat Microbiol 2021; 7:145-153. [PMID: 34887546 DOI: 10.1038/s41564-021-01008-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/26/2021] [Indexed: 01/23/2023]
Abstract
Temperate bacterial viruses (phages) can transition between lysis-replicating and killing the host-and lysogeny, that is, existing as dormant prophages while keeping the host viable. Recent research showed that on invading a naïve cell, some phages communicate using a peptide signal, termed arbitrium, to control the decision of entering lysogeny. Whether communication can also serve to regulate exit from lysogeny (known as phage induction) is unclear. Here we show that arbitrium-coding prophages continue to communicate from the lysogenic state by secreting and sensing the arbitrium signal. Signalling represses DNA damage-dependent phage induction, enabling prophages to reduce the induction rate when surrounded by other lysogens. We show that in certain phages, DNA damage and communication converge to regulate the expression of the arbitrium-responsive gene aimX, while in others integration of DNA damage and communication occurs downstream of aimX expression. Additionally, signalling by prophages tilts the decision of nearby infecting phages towards lysogeny. Altogether, we find that phages use small-molecule communication throughout their entire life cycle to sense the abundance of lysogens in the population, thus avoiding lysis when they are likely to encounter established lysogens rather than permissive uninfected hosts.
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Affiliation(s)
- Nitzan Aframian
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Shira Omer Bendori
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Stav Kabel
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Polina Guler
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | | | - Erica Manor
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Kholod Msaeed
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Valeria Lipsman
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.,Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Ilana Grinberg
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Alaa Mahagna
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Avigdor Eldar
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
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21
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Pei K, Zhang J, Zou T, Liu Z. AimR Adopts Preexisting Dimer Conformations for Specific Target Recognition in Lysis-Lysogeny Decisions of Bacillus Phage phi3T. Biomolecules 2021; 11:biom11091321. [PMID: 34572534 PMCID: PMC8464984 DOI: 10.3390/biom11091321] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/30/2021] [Accepted: 09/05/2021] [Indexed: 12/04/2022] Open
Abstract
A bacteriophage switches between lytic and lysogenic life cycles. The AimR-AimP-AimX communication system is responsible for phage lysis-lysogeny decisions during the infection of Bacillus subtilis. AimX is a regulator biasing phage lysis, AimR is a transcription factor activating AimX expression, and AimP is an arbitrium peptide that determines phage lysogeny by deactivating AimR. A strain-specific mechanism for the lysis-lysogeny decisions is proposed in SPbeta and phi3T phages. That is, the arbitrium peptide of the SPbeta phage stabilizes the SPbeta AimR (spAimR) dimer, whereas the phi3T-derived peptide disassembles the phi3T AimR (phAimR) dimer into a monomer. Here, we find that phAimR does not undergo dimer-to-monomer conversion upon arbitrium peptide binding. Gel-filtration, static light scattering (SLS) and analytical ultracentrifugation (AUC) results show that phAimR is dimeric regardless of the presence of arbitrium peptide. Small-angle X-ray scattering (SAXS) reveals that the arbitrium peptide binding makes an extended dimeric conformation. Single-molecule fluorescence resonance energy transfer (smFRET) analysis reveals that the phAimR dimer fluctuates among two distinct conformational states, and each preexisting state is selectively recognized by the arbitrium peptide or the target DNA, respectively. Collectively, our biophysical characterization of the phAimR dynamics underlying specific target recognition provides new mechanistic insights into understanding lysis-lysogeny decisions in Bacillus phage phi3T.
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22
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Abstract
Phages are viruses of bacteria and are the smallest and most common biological entities in the environment. They can reproduce immediately after infection or integrate as a prophage into their host genome. SPβ is a prophage of the Gram-positive model organism Bacillus subtilis 168, and it has been known for more than 50 years. It is sensitive to dsDNA damage and is induced through exposure to mitomycin C or UV radiation. When induced from the prophage, SPβ requires 90 min to produce and release about 30 virions. Genomes of sequenced related strains range between 128 and 140 kb, and particle-packed dsDNA exhibits terminal redundancy. Formed particles are of the Siphoviridae morphotype. Related isolates are known to infect other B. subtilis clade members. When infecting a new host, SPβ presumably follows a two-step strategy, adsorbing primarily to teichoic acid and secondarily to a yet unknown factor. Once in the host, SPβ-related phages pass through complex lysis-lysogeny decisions and either enter a lytic cycle or integrate as a dormant prophage. As prophages, SPβ-related phages integrate at the host chromosome's replication terminus, and frequently into the spsM or kamA gene. As a prophage, it imparts additional properties to its host via phage-encoded proteins. The most notable of these functional proteins is sublancin 168, which is used as a molecular weapon by the host and ensures prophage maintenance. In this review, we summarise the existing knowledge about the biology of the phage regarding its life cycle and discuss its potential as a research object.
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Affiliation(s)
- Katharina Kohm
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, 01968, Senftenberg, Germany.
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23
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Marshall CW, Gloag ES, Lim C, Wozniak DJ, Cooper VS. Rampant prophage movement among transient competitors drives rapid adaptation during infection. SCIENCE ADVANCES 2021; 7:7/29/eabh1489. [PMID: 34272240 PMCID: PMC8284892 DOI: 10.1126/sciadv.abh1489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/03/2021] [Indexed: 05/11/2023]
Abstract
Interactions between bacteria, their close competitors, and viral parasites are common in infections, but understanding of these eco-evolutionary dynamics is limited. Most examples of adaptations caused by phage lysogeny are through the acquisition of new genes. However, integrated prophages can also insert into functional genes and impart a fitness benefit by disrupting their expression, a process called active lysogeny. Here, we show that active lysogeny can fuel rapid, parallel adaptations in establishing a chronic infection. These recombination events repeatedly disrupted genes encoding global regulators, leading to increased cyclic di-GMP levels and elevated biofilm production. The implications of prophage-mediated adaptation are broad, as even transient members of microbial communities can alter the course of evolution and generate persistent phenotypes associated with poor clinical outcomes.
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Affiliation(s)
| | - Erin S Gloag
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
| | - Christina Lim
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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24
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Dragoš A, Andersen AJC, Lozano-Andrade CN, Kempen PJ, Kovács ÁT, Strube ML. Phages carry interbacterial weapons encoded by biosynthetic gene clusters. Curr Biol 2021; 31:3479-3489.e5. [PMID: 34186025 DOI: 10.1016/j.cub.2021.05.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 04/16/2021] [Accepted: 05/20/2021] [Indexed: 01/08/2023]
Abstract
Bacteria produce diverse specialized metabolites that mediate ecological interactions and serve as a rich source of industrially relevant natural products. Biosynthetic pathways for these metabolites are encoded by organized groups of genes called biosynthetic gene clusters (BGCs). Understanding the natural function and distribution of BGCs provides insight into the mechanisms through which microorganisms interact and compete. Further, understanding BGCs is extremely important for biocontrol and the mining of new bioactivities. Here, we investigated phage-encoded BGCs (pBGCs), challenging the relationship between phage origin and BGC structure and function. The results demonstrated that pBGCs are rare, and they predominantly reside within temperate phages infecting commensal or pathogenic bacterial hosts. Further, the vast majority of pBGCs were found to encode for bacteriocins. Using the soil- and gut-associated bacterium Bacillus subtilis, we experimentally demonstrated how a temperate phage equips a bacterium with a fully functional BGC, providing a clear competitive fitness advantage over the ancestor. Moreover, we demonstrated a similar transfer of the same phage in prophage form. Finally, using genetic and genomic comparisons, a strong association between pBGC type and phage host range was revealed. These findings suggest that bacteriocins are encoded in temperate phages of a few commensal bacterial genera. In these cases, lysogenic conversion provides an evolutionary benefit to the infected host and, hence, to the phage itself. This study is an important step toward understanding the natural role of bacterial compounds encoded by BGCs, the mechanisms driving their horizontal transfer, and the sometimes mutualistic relationship between bacteria and temperate phages.
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Affiliation(s)
- Anna Dragoš
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark.
| | - Aaron J C Andersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark
| | - Carlos N Lozano-Andrade
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark
| | - Paul J Kempen
- Department of Health Technology, Technical University of Denmark, Produktionstorvet bldg. 423, DK-2800 Kgs Lyngby, Denmark; National Center for Nano Fabrication and Characterization, Technical University of Denmark, Fysikvej bldg. 307, DK-2800 Kgs Lyngby, Denmark
| | - Ákos T Kovács
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark
| | - Mikael Lenz Strube
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark.
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25
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Abe K, Toyofuku M, Nomura N, Obana N. Autolysis-mediated membrane vesicle formation in Bacillus subtilis. Environ Microbiol 2021; 23:2632-2647. [PMID: 33817925 DOI: 10.1111/1462-2920.15502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 04/03/2021] [Indexed: 12/19/2022]
Abstract
It is known that Bacillus subtilis releases membrane vesicles (MVs) during the SOS response, which is associated with cell lysis triggered by the PBSX prophage-encoded cell-lytic enzymes XhlAB and XlyA. In this study, we demonstrate that MVs are released under various stress conditions: sucrose fatty acid ester (SFE; surfactant) treatment, cold shock, starvation, and oxygen deficiency. B. subtilis possesses four major host-encoded cell wall-lytic enzymes (autolysins; LytC, LytD, LytE, and LytF). Deletions of the autolysin genes abolished autolysis and the consequent MV production under these stress conditions. In contrast, deletions of xhlAB and xlyA had no effect on autolysis-triggered MV biogenesis, indicating that autolysis is a novel and prophage-independent pathway for MV production in B. subtilis. Moreover, we found that the cell lysis induced by the surfactant treatment was effectively neutralized by the addition of exogenous purified MVs. This result suggests that the MVs can serve as a decoy for the cellular membrane to protect the living cells in the culture from membrane damage by the surfactant. Our results indicate a positive effect of B. subtilis MVs on cell viability and provide new insight into the biological importance of the autolysis phenomenon in B. subtilis.
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Affiliation(s)
- Kimihiro Abe
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Masanori Toyofuku
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, Ibaraki, Japan
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, Ibaraki, Japan
| | - Nozomu Obana
- Microbiology Research Center for Sustainability, University of Tsukuba, Ibaraki, Japan.,Transborder Medical Research Center, University of Tsukuba, Ibaraki, Japan
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26
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Shi L, Derouiche A, Pandit S, Rahimi S, Kalantari A, Futo M, Ravikumar V, Jers C, Mokkapati VRSS, Vlahoviček K, Mijakovic I. Evolutionary Analysis of the Bacillus subtilis Genome Reveals New Genes Involved in Sporulation. Mol Biol Evol 2021; 37:1667-1678. [PMID: 32061128 PMCID: PMC7426031 DOI: 10.1093/molbev/msaa035] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bacilli can form dormant, highly resistant, and metabolically inactive spores to cope with extreme environmental challenges. In this study, we examined the evolutionary age of Bacillus subtilis sporulation genes using the approach known as genomic phylostratigraphy. We found that B. subtilis sporulation genes cluster in several groups that emerged at distant evolutionary time-points, suggesting that the sporulation process underwent several stages of expansion. Next, we asked whether such evolutionary stratification of the genome could be used to predict involvement in sporulation of presently uncharacterized genes (y-genes). We individually inactivated a representative sample of uncharacterized genes that arose during the same evolutionary periods as the known sporulation genes and tested the resulting strains for sporulation phenotypes. Sporulation was significantly affected in 16 out of 37 (43%) tested strains. In addition to expanding the knowledge base on B. subtilis sporulation, our findings suggest that evolutionary age could be used to help with genome mining.
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Affiliation(s)
- Lei Shi
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Abderahmane Derouiche
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Santosh Pandit
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Shadi Rahimi
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Aida Kalantari
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Momir Futo
- Laboratory of Evolutionary Genetics, Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Vaishnavi Ravikumar
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Carsten Jers
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Venkata R S S Mokkapati
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Kristian Vlahoviček
- Bioinformatics group, Division of Molecular Biology, Department of Biology, Faculty of Science, University of Zagreb, Croatia.,School of Bioscience, University of Skövde, Skövde, Sweden
| | - Ivan Mijakovic
- Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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27
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Dergham Y, Sanchez-Vizuete P, Le Coq D, Deschamps J, Bridier A, Hamze K, Briandet R. Comparison of the Genetic Features Involved in Bacillus subtilis Biofilm Formation Using Multi-Culturing Approaches. Microorganisms 2021; 9:microorganisms9030633. [PMID: 33803642 PMCID: PMC8003051 DOI: 10.3390/microorganisms9030633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
Abstract
Surface-associated multicellular assemblage is an important bacterial trait to withstand harsh environmental conditions. Bacillus subtilis is one of the most studied Gram-positive bacteria, serving as a model for the study of genetic pathways involved in the different steps of 3D biofilm formation. B. subtilis biofilm studies have mainly focused on pellicle formation at the air-liquid interface or complex macrocolonies formed on nutritive agar. However, only few studies focus on the genetic features of B. subtilis submerged biofilm formation and their link with other multicellular models at the air interface. NDmed, an undomesticated B. subtilis strain isolated from a hospital, has demonstrated the ability to produce highly structured immersed biofilms when compared to strains classically used for studying B. subtilis biofilms. In this contribution, we have conducted a multi-culturing comparison (between macrocolony, swarming, pellicle, and submerged biofilm) of B. subtilis multicellular communities using the NDmed strain and mutated derivatives for genes shown to be required for motility and biofilm formation in pellicle and macrocolony models. For the 15 mutated NDmed strains studied, all showed an altered phenotype for at least one of the different culture laboratory assays. Mutation of genes involved in matrix production (i.e., tasA, epsA-O, cap, ypqP) caused a negative impact on all biofilm phenotypes but favored swarming motility on semi-solid surfaces. Mutation of bslA, a gene coding for an amphiphilic protein, affected the stability of the pellicle at the air-liquid interface with no impact on the submerged biofilm model. Moreover, mutation of lytF, an autolysin gene required for cell separation, had a greater effect on the submerged biofilm model than that formed at aerial level, opposite to the observation for lytABC mutant. In addition, B. subtilis NDmed with sinR mutation formed wrinkled macrocolony, less than that formed by the wild type, but was unable to form neither thick pellicle nor structured submerged biofilm. The results are discussed in terms of the relevancy to determine whether genes involved in colony and pellicle formation also govern submerged biofilm formation, by regarding the specificities in each model.
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Affiliation(s)
- Yasmine Dergham
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (Y.D.); (P.S.-V.); (D.L.C.); (J.D.)
- Faculty of Science, Lebanese University, 1003 Beirut, Lebanon;
| | - Pilar Sanchez-Vizuete
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (Y.D.); (P.S.-V.); (D.L.C.); (J.D.)
| | - Dominique Le Coq
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (Y.D.); (P.S.-V.); (D.L.C.); (J.D.)
- Centre National de la Recherche Scientifique (CNRS), Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Julien Deschamps
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (Y.D.); (P.S.-V.); (D.L.C.); (J.D.)
| | - Arnaud Bridier
- Fougères Laboratory, Antibiotics, Biocides, Residues and Resistance Unit, Anses, 35300 Fougères, France;
| | - Kassem Hamze
- Faculty of Science, Lebanese University, 1003 Beirut, Lebanon;
| | - Romain Briandet
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (Y.D.); (P.S.-V.); (D.L.C.); (J.D.)
- Correspondence:
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28
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Dragoš A, Priyadarshini B, Hasan Z, Strube ML, Kempen PJ, Maróti G, Kaspar C, Bose B, Burton BM, Bischofs IB, Kovács ÁT. Pervasive prophage recombination occurs during evolution of spore-forming Bacilli. ISME JOURNAL 2020; 15:1344-1358. [PMID: 33343000 DOI: 10.1038/s41396-020-00854-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/12/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023]
Abstract
Phages are the main source of within-species bacterial diversity and drivers of horizontal gene transfer, but we know little about the mechanisms that drive genetic diversity of these mobile genetic elements (MGEs). Recently, we showed that a sporulation selection regime promotes evolutionary changes within SPβ prophage of Bacillus subtilis, leading to direct antagonistic interactions within the population. Herein, we reveal that under a sporulation selection regime, SPβ recombines with low copy number phi3Ts phage DNA present within the B. subtilis population. Recombination results in a new prophage occupying a different integration site, as well as the spontaneous release of virulent phage hybrids. Analysis of Bacillus sp. strains suggests that SPβ and phi3T belong to a distinct cluster of unusually large phages inserted into sporulation-related genes that are equipped with a spore-related genetic arsenal. Comparison of Bacillus sp. genomes indicates that similar diversification of SPβ-like phages takes place in nature. Our work is a stepping stone toward empirical studies on phage evolution, and understanding the eco-evolutionary relationships between bacteria and their phages. By capturing the first steps of new phage evolution, we reveal striking relationship between survival strategy of bacteria and evolution of their phages.
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Affiliation(s)
- Anna Dragoš
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
| | - B Priyadarshini
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Zahraa Hasan
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Mikael Lenz Strube
- Bacterial Ecophysiology and Biotechnology Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Paul J Kempen
- Department of Health Technology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, H-6701, Hungary
| | - Charlotte Kaspar
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | | | - Briana M Burton
- Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA
| | - Ilka B Bischofs
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
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29
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Abe K, Takahashi T, Sato T. Extreme C-terminal element of SprA serine integrase is a potential component of the "molecular toggle switch" which controls the recombination and its directionality. Mol Microbiol 2020; 115:1110-1121. [PMID: 33244797 DOI: 10.1111/mmi.14654] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 10/26/2020] [Accepted: 11/21/2020] [Indexed: 12/11/2022]
Abstract
In Bacillus subtilis, a sporulation-related gene, spsM, is disrupted by SPβ prophage, but reconstituted during sporulation through SPβ excision. The spsM reconstitution is catalyzed by a site-specific DNA recombinase, SprA, and its cognate recombination directionality factor, SprB. SprB interacts with SprA, directing the SprA-mediated recombination reaction from integration to excision; however, the details of the directionality control remains unclear. Here, we demonstrate the importance of the extreme C-terminal region (ECT) of SprA in the DNA recombination and directionality control. We created a series of SprA C-terminal deletants and examined their DNA-binding and recombination activities. Deletions in the ECT caused a loss of integration and excision activity, the magnitudes of which positively correlated with the deletion size. Gel shift study revealed that the loss of the integration activity was attributable to the failure of synaptic complex formation. The excision deficiency was caused by defective interaction with SprB. Moreover, alanine scanning analysis revealed that Phe532 is essential to interact with SprB. SprAF532A , therefore, showed almost no excision activity, while retaining the integration activity. Collectively, these results suggest that the ECT plays the crucial roles in the interaction of SprA with SprB and possibly in the directional control of the recombination.
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Affiliation(s)
- Kimihiro Abe
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Japan
| | - Takumi Takahashi
- Department of Frontier Bioscience, Hosei University, Koganei, Japan
| | - Tsutomu Sato
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Japan.,Department of Frontier Bioscience, Hosei University, Koganei, Japan
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30
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Abe K, Nomura N, Suzuki S. Biofilms: hot spots of horizontal gene transfer (HGT) in aquatic environments, with a focus on a new HGT mechanism. FEMS Microbiol Ecol 2020; 96:5766226. [PMID: 32109282 PMCID: PMC7189800 DOI: 10.1093/femsec/fiaa031] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/27/2020] [Indexed: 12/21/2022] Open
Abstract
Biofilms in water environments are thought to be hot spots for horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). ARGs can be spread via HGT, though mechanisms are known and have been shown to depend on the environment, bacterial communities and mobile genetic elements. Classically, HGT mechanisms include conjugation, transformation and transduction; more recently, membrane vesicles (MVs) have been reported as DNA reservoirs implicated in interspecies HGT. Here, we review the current knowledge on the HGT mechanisms with a focus on the role of MVs and the methodological innovations in the HGT research.
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Affiliation(s)
- Kimihiro Abe
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8577 Japan
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8577 Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, Tsukuba, 305-8577 Japan
| | - Satoru Suzuki
- Center for Marine Environmental Studies, Ehime University, Matsuyama, 790-8577 Japan
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31
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Nasukawa T, Sugimoto R, Uchiyama J, Takemura-Uchiyama I, Murakami H, Fukuda K, Matsuzaki S, Sakaguchi M. Purification of membrane vesicles from Gram-positive bacteria using flow cytometry, after iodixanol density-gradient ultracentrifugation. Res Microbiol 2020; 172:103792. [PMID: 33220407 DOI: 10.1016/j.resmic.2020.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/06/2020] [Accepted: 11/06/2020] [Indexed: 11/20/2022]
Abstract
Membrane vesicles (MVs) play biologically important roles in Gram-positive bacteria, and purification is essential for their study. Although high-performance flow cytometry has the capability to quantify and isolate specific small particles, it has not been examined for MV isolation. In this study, we used high-performance flow cytometry to analyze MV from Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, prepared by iodixanol density-gradient ultracentrifugation. Analysis of the quality of MV samples before and after sorting showed that the flow cytometric sorting provided higher purity and uniformity compared to gradient isolation alone. The MV purification method using flow cytometry should prove useful for applications requiring a very high purity of MV samples such as proteomic, metagenomic or lipidomic studies.
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Affiliation(s)
| | - Ryosuke Sugimoto
- School of Veterinary Medicine, Azabu University, Kanagawa, Japan
| | - Jumpei Uchiyama
- School of Veterinary Medicine, Azabu University, Kanagawa, Japan.
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32
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Kleiner M, Bushnell B, Sanderson KE, Hooper LV, Duerkop BA. Transductomics: sequencing-based detection and analysis of transduced DNA in pure cultures and microbial communities. MICROBIOME 2020; 8:158. [PMID: 33190645 PMCID: PMC7667829 DOI: 10.1186/s40168-020-00935-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Horizontal gene transfer (HGT) plays a central role in microbial evolution. Our understanding of the mechanisms, frequency, and taxonomic range of HGT in polymicrobial environments is limited, as we currently rely on historical HGT events inferred from genome sequencing and studies involving cultured microorganisms. We lack approaches to observe ongoing HGT in microbial communities. RESULTS To address this knowledge gap, we developed a DNA sequencing-based "transductomics" approach that detects and characterizes microbial DNA transferred via transduction. We validated our approach using model systems representing a range of transduction modes and show that we can detect numerous classes of transducing DNA. Additionally, we show that we can use this methodology to obtain insights into DNA transduction among all major taxonomic groups of the intestinal microbiome. CONCLUSIONS The transductomics approach that we present here allows for the detection and characterization of genes that are potentially transferred between microbes in complex microbial communities at the time of measurement and thus provides insights into real-time ongoing horizontal gene transfer. This work extends the genomic toolkit for the broader study of mobile DNA within microbial communities and could be used to understand how phenotypes spread within microbiomes. Video Abstract.
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Affiliation(s)
- Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA.
| | - Brian Bushnell
- Department of Energy, Joint Genome Institute, Walnut Creek, CA, USA
| | - Kenneth E Sanderson
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Lora V Hooper
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Breck A Duerkop
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA.
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33
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Johnson GE, Lalanne JB, Peters ML, Li GW. Functionally uncoupled transcription-translation in Bacillus subtilis. Nature 2020; 585:124-128. [PMID: 32848247 PMCID: PMC7483943 DOI: 10.1038/s41586-020-2638-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/22/2020] [Indexed: 11/10/2022]
Abstract
Tight coupling of transcription and translation is considered a defining feature of bacterial gene expression1,2. The pioneering ribosome can both physically associate and kinetically coordinate with RNA polymerase (RNAP)3-11, forming a signal-integration hub for co-transcriptional regulation that includes translation-based attenuation12,13 and RNA quality control2. However, it remains unclear whether transcription-translation coupling-together with its broad functional consequences-is indeed a fundamental characteristic of bacteria other than Escherichia coli. Here we show that RNAPs outpace pioneering ribosomes in the Gram-positive model bacterium Bacillus subtilis, and that this 'runaway transcription' creates alternative rules for both global RNA surveillance and translational control of nascent RNA. In particular, uncoupled RNAPs in B. subtilis explain the diminished role of Rho-dependent transcription termination, as well as the prevalence of mRNA leaders that use riboswitches and RNA-binding proteins. More broadly, we identified widespread genomic signatures of runaway transcription in distinct phyla across the bacterial domain. Our results show that coupled RNAP-ribosome movement is not a general hallmark of bacteria. Instead, translation-coupled transcription and runaway transcription constitute two principal modes of gene expression that determine genome-specific regulatory mechanisms in prokaryotes.
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Affiliation(s)
- Grace E Johnson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jean-Benoît Lalanne
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michelle L Peters
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Gene-Wei Li
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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34
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The sps Genes Encode an Original Legionaminic Acid Pathway Required for Crust Assembly in Bacillus subtilis. mBio 2020; 11:mBio.01153-20. [PMID: 32817102 PMCID: PMC7439481 DOI: 10.1128/mbio.01153-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The crust is the outermost spore layer of most Bacillus strains devoid of an exosporium. This outermost layer, composed of both proteins and carbohydrates, plays a major role in the adhesion and spreading of spores into the environment. Recent studies have identified several crust proteins and have provided insights about their organization at the spore surface. However, although carbohydrates are known to participate in adhesion, little is known about their composition, structure, and localization. In this study, we showed that the spore surface of Bacillus subtilis is covered with legionaminic acid (Leg), a nine-carbon backbone nonulosonic acid known to decorate the flagellin of the human pathogens Helicobacter pylori and Campylobacter jejuni We demonstrated that the spsC, spsD, spsE, spsG, and spsM genes of Bacillus subtilis are required for Leg biosynthesis during sporulation, while the spsF gene is required for Leg transfer from the mother cell to the surface of the forespore. We also characterized the activity of SpsM and highlighted an original Leg biosynthesis pathway in B. subtilis Finally, we demonstrated that Leg is required for the assembly of the crust around the spores, and we showed that in the absence of Leg, spores were more adherent to stainless steel probably because of their reduced hydrophilicity and charge.IMPORTANCE Bacillus species are a major economic and food safety concern of the food industry because of their food spoilage-causing capability and persistence. Their persistence is mainly due to their ability to form highly resistant spores adhering to the surfaces of industrial equipment. Spores of the Bacillus subtilis group are surrounded by the crust, a superficial layer which plays a key role in their adhesion properties. However, knowledge of the composition and structure of this layer remains incomplete. Here, for the first time, we identified a nonulosonic acid (Leg) at the surfaces of bacterial spores (B. subtilis). We uncovered a novel Leg biosynthesis pathway, and we demonstrated that Leg is required for proper crust assembly. This work contributes to the description of the structure and composition of Bacillus spores which has been under way for decades, and it provides keys to understanding the importance of carbohydrates in Bacillus adhesion and persistence in the food industry.
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35
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Compatibility of Site-Specific Recombination Units between Mobile Genetic Elements. iScience 2019; 23:100805. [PMID: 31926432 PMCID: PMC6957869 DOI: 10.1016/j.isci.2019.100805] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/06/2019] [Accepted: 12/19/2019] [Indexed: 12/17/2022] Open
Abstract
Site-specific recombination (SSR) systems are employed for transfer of mobile genetic elements (MGEs), such as lysogenic phages and integrative conjugative elements (ICEs). SSR between attP/I and attB sites is mediated by an integrase (Int) and a recombination directionality factor (RDF). The genome of Bacillus subtilis 168 contains SPβ, an active prophage, skin, a defective prophage, and ICEBs1, an integrative conjugative element. Each of these MGEs harbors the classic SSR unit attL-int-rdf-attR. Here, we demonstrate that these SSR units are all compatible and can substitute for one another. Specifically, when SPβ is turned into a defective prophage by deletion of its SSR unit, introduction of the SSR unit of skin or ICE converts it back to an active prophage. We also identified closely related prophages with distinct SSR units that control developmentally regulated gene rearrangements of kamA (L-lysine 2,3-aminomutase). These results suggest that SSR units are interchangeable components of MGEs. Lysogenic phage-derived SSR unit is sufficient to drive SSR of ICE and vice versa Defective prophage-derived SSR unit can drive the excision of the active lysogenic phage Closely related prophages with distinct SSR units control each gene rearrangements Correspondence between MGEs and their cognate SSR units is not absolute
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Bartels J, Blüher A, López Castellanos S, Richter M, Günther M, Mascher T. The
Bacillus subtilis
endospore crust: protein interaction network, architecture and glycosylation state of a potential glycoprotein layer. Mol Microbiol 2019; 112:1576-1592. [DOI: 10.1111/mmi.14381] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Julia Bartels
- Institute of Microbiology Technische Universität (TU) Dresden Dresden 01062Germany
| | - Anja Blüher
- School of Engineering Science Institute of Materials Science Technische Universität (TU) Dresden Dresden 01062Germany
| | | | - Marcus Richter
- Institute of Microbiology Technische Universität (TU) Dresden Dresden 01062Germany
| | - Markus Günther
- Institute of Botany Technische Universität (TU) Dresden Dresden 01062Germany
| | - Thorsten Mascher
- Institute of Microbiology Technische Universität (TU) Dresden Dresden 01062Germany
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37
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Expansion of the Spore Surface Polysaccharide Layer in Bacillus subtilis by Deletion of Genes Encoding Glycosyltransferases and Glucose Modification Enzymes. J Bacteriol 2019; 201:JB.00321-19. [PMID: 31235516 DOI: 10.1128/jb.00321-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/18/2019] [Indexed: 12/16/2022] Open
Abstract
Polysaccharides (PS) decorate the surface of dormant endospores (spores). In the model organism for sporulation, Bacillus subtilis, the composition of the spore PS is not known in detail. Here, we have assessed how PS synthesis enzymes produced during the late stages of sporulation affect spore surface properties. Using four methods, bacterial adhesion to hydrocarbons (BATH) assays, India ink staining, transmission electron microscopy (TEM) with ruthenium red staining, and scanning electron microscopy (SEM), we characterized the contributions of four sporulation gene clusters, spsABCDEFGHIJKL, yfnHGF-yfnED, ytdA-ytcABC, and cgeAB-cgeCDE, on the morphology and properties of the crust, the outermost spore layer. Our results show that all mutations in the sps operon result in the production of spores that are more hydrophobic and lack a visible crust, presumably because of reduced PS deposition, while mutations in cgeD and the yfnH-D cluster noticeably expand the PS layer. In addition, yfnH-D mutant spores exhibit a crust with an unusual weblike morphology. The hydrophobic phenotype from sps mutant spores was partially rescued by a second mutation inactivating any gene in the yfnHGF operon. While spsI, yfnH, and ytdA are paralogous genes, all encoding glucose-1-phosphate nucleotidyltransferases, each paralog appears to contribute in a distinct manner to the spore PS. Our data are consistent with the possibility that each gene cluster is responsible for the production of its own respective deoxyhexose. In summary, we found that disruptions to the PS layer modify spore surface hydrophobicity and that there are multiple saccharide synthesis pathways involved in spore surface properties.IMPORTANCE Many bacteria are characterized by their ability to form highly resistant spores. The dormant spore state allows these species to survive even the harshest treatments with antimicrobial agents. Spore surface properties are particularly relevant because they influence spore dispersal in various habitats from natural to human-made environments. The spore surface in Bacillus subtilis (crust) is composed of a combination of proteins and polysaccharides. By inactivating the enzymes responsible for the synthesis of spore polysaccharides, we can assess how spore surface properties such as hydrophobicity are modulated by the addition of specific carbohydrates. Our findings indicate that several sporulation gene clusters are responsible for the assembly and allocation of surface polysaccharides. Similar mechanisms could be modulating the dispersal of infectious spore-forming bacteria.
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38
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Zeng Z, Zhan W, Wang W, Wang P, Tang K, Wang X. Biofilm formation in Pseudoalteromonas lipolytica is related to IS5-like insertions in the capsular polysaccharide operon. FEMS Microbiol Ecol 2019; 95:5488432. [PMID: 31077283 DOI: 10.1093/femsec/fiz065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 05/10/2019] [Indexed: 11/14/2022] Open
Abstract
Bacterial capsular polysaccharides (CPSs) participate in environmental adaptation in diverse bacteria species. However, the role and regulation of CPS production in marine bacteria have remained largely unexplored. We previously reported that both wrinkled and translucent Pseudoalteromonas lipolytica variants with altered polysaccharide production were generated in pellicle biofilm-associated cells. In this study, we observed that translucent variants were generated at a rate of ∼20% in colony biofilms of P. lipolytica cultured on HSLB agar plates for 12 days. The DNA sequencing results revealed that nearly 90% of these variants had an IS5-like element inserted within the coding or promoter regions of nine genes in the cps operon. In contrast, IS5 insertion into the cps operon was not detected in planktonic cells. Furthermore, we demonstrated that the IS5 insertion event inactivated CPS production, which leads to a translucent colony morphology. The CPS-deficient variants showed an increased ability to form attached biofilms but exhibited reduced resistance to sublethal concentrations of antibiotics. Moreover, deleting the DNA repair gene recA significantly decreased the frequency of occurrence of CPS-deficient variants during biofilm formation. Thus, IS insertion into the cps operon is an important mechanism for the production of genetic variants during biofilm formation of marine bacteria.
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Affiliation(s)
- Zhenshun Zeng
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Waner Zhan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weiquan Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengxia Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Kaihao Tang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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39
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Noda-García L, Davidi D, Korenblum E, Elazar A, Putintseva E, Aharoni A, Tawfik DS. Chance and pleiotropy dominate genetic diversity in complex bacterial environments. Nat Microbiol 2019; 4:1221-1230. [PMID: 30936490 DOI: 10.1038/s41564-019-0412-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 02/14/2019] [Indexed: 12/18/2022]
Abstract
How does environmental complexity affect the evolution of single genes? Here, we measured the effects of a set of Bacillus subtilis glutamate dehydrogenase mutants across 19 different environments-from phenotypically homogeneous single-cell populations in liquid media to heterogeneous biofilms, plant roots and soil populations. The effects of individual gene mutations on organismal fitness were highly reproducible in liquid cultures. However, 84% of the tested alleles showed opposing fitness effects under different growth conditions (sign environmental pleiotropy). In colony biofilms and soil samples, different alleles dominated in parallel replica experiments. Accordingly, we found that in these heterogeneous cell populations the fate of mutations was dictated by a combination of selection and drift. The latter relates to programmed prophage excisions that occurred during biofilm development. Overall, for each condition, a wide range of glutamate dehydrogenase mutations persisted and sometimes fixated as a result of the combined action of selection, pleiotropy and chance. However, over longer periods and in multiple environments, nearly all of this diversity would be lost-across all the environments and conditions that we tested, the wild type was the fittest allele.
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Affiliation(s)
- Lianet Noda-García
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Dan Davidi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Elisa Korenblum
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Assaf Elazar
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | | | - Asaph Aharoni
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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40
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Ramisetty BCM, Sudhakari PA. Bacterial 'Grounded' Prophages: Hotspots for Genetic Renovation and Innovation. Front Genet 2019; 10:65. [PMID: 30809245 PMCID: PMC6379469 DOI: 10.3389/fgene.2019.00065] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/24/2019] [Indexed: 01/07/2023] Open
Abstract
Bacterial genomes are highly plastic allowing the generation of variants through mutations and acquisition of genetic information. The fittest variants are then selected by the econiche thereby allowing the bacterial adaptation and colonization of the habitat. Larger genomes, however, may impose metabolic burden and hence bacterial genomes are optimized by the loss of frivolous genetic information. The activity of temperate bacteriophages has acute consequences on the bacterial population as well as the bacterial genome through lytic and lysogenic cycles. Lysogeny is a selective advantage as the prophage provides immunity to the lysogen against secondary phage attack. Since the non-lysogens are eliminated by the lytic phages, lysogens multiply and colonize the habitat. Nevertheless, all lysogens have an imminent risk of lytic cycle activation and cell lysis. However, a mutation in the attachment sites or in the genes that encode the specific recombinase responsible for prophage excision could result in 'grounding' of the prophage. Since the lysogens with grounded prophage are immune to respective phage infection as well as dodge the induction of lytic cycle, we hypothesize that the selection of these mutant lysogens is favored relative to their normal lysogenic counterparts. These grounded prophages offer several advantages to the bacterial genome evolution through propensity for genetic variations including inversions, deletions, and insertions via horizontal gene transfer. We propose that the grounded prophages expedite bacterial genome evolution by acting as 'genetic buffer zones' thereby increasing the frequency as well as the diversity of variations on which natural selection favors the beneficial variants. The grounded prophages are also hotspots for horizontal gene transfer wherein several ecologically significant genes such as those involved in stress tolerance, antimicrobial resistance, and novel metabolic pathways, are integrated. Moreover, the high frequency of genetic changes within prophages also allows proportionate probability for the de novo genesis of genetic information. Through sequence analyses of well-characterized E. coli prophages we exemplify various roles of grounded prophages in E. coli ecology and evolution. Therefore, the temperate prophages are one of the most significant drivers of bacterial genome evolution and sites of biogenesis of genetic information.
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Affiliation(s)
- Bhaskar Chandra Mohan Ramisetty
- Laboratory of Molecular Biology and Evolution, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, India
| | - Pavithra Anantharaman Sudhakari
- Laboratory of Molecular Biology and Evolution, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, India
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41
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Shuster B, Khemmani M, Abe K, Huang X, Nakaya Y, Maryn N, Buttar S, Gonzalez AN, Driks A, Sato T, Eichenberger P. Contributions of crust proteins to spore surface properties in Bacillus subtilis. Mol Microbiol 2019; 111:825-843. [PMID: 30582883 DOI: 10.1111/mmi.14194] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/27/2022]
Abstract
Surface properties, such as adhesion and hydrophobicity, constrain dispersal of bacterial spores in the environment. In Bacillus subtilis, these properties are influenced by the outermost layer of the spore, the crust. Previous work has shown that two clusters, cotVWXYZ and cgeAB, encode the protein components of the crust. Here, we characterize the respective roles of these genes in surface properties using Bacterial Adherence to Hydrocarbons assays, negative staining of polysaccharides by India ink and Transmission Electron Microscopy. We showed that inactivation of crust genes caused increases in spore relative hydrophobicity, disrupted the spore polysaccharide layer, and impaired crust structure and attachment to the rest of the coat. We also found that cotO, previously identified for its role in outer coat formation, is necessary for proper encasement of the spore by the crust. In parallel, we conducted fluorescence microscopy experiments to determine the full network of genetic dependencies for subcellular localization of crust proteins. We determined that CotZ is required for the localization of most crust proteins, while CgeA is at the bottom of the genetic interaction hierarchy.
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Affiliation(s)
- Bentley Shuster
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
| | - Mark Khemmani
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Kimihiro Abe
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
| | - Xiaoyu Huang
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
| | - Yusei Nakaya
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Nina Maryn
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
| | - Sally Buttar
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
| | - Adriana N Gonzalez
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
| | - Adam Driks
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Tsutomu Sato
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan.,Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Patrick Eichenberger
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, 10003, USA
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42
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Abstract
Bacteriophages, discovered about a century ago, have been pivotal as models for understanding the fundamental principles of molecular biology. While interest in phage biology declined after the phage "golden era," key recent developments, including advances in phage genomics, microscopy, and the discovery of the CRISPR-Cas anti-phage defense system, have sparked a renaissance in phage research in the past decade. This review highlights recently discovered unexpected complexities in phage biology, describes a new arsenal of phage genes that help them overcome bacterial defenses, and discusses advances toward documentation of the phage biodiversity on a global scale.
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Affiliation(s)
- Gal Ofir
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rotem Sorek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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43
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In-depth analysis of Bacillus subtilis proteome identifies new ORFs and traces the evolutionary history of modified proteins. Sci Rep 2018; 8:17246. [PMID: 30467398 PMCID: PMC6250715 DOI: 10.1038/s41598-018-35589-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/07/2018] [Indexed: 01/05/2023] Open
Abstract
Bacillus subtilis is a sporulating Gram-positive bacterium widely used in basic research and biotechnology. Despite being one of the best-characterized bacterial model organism, recent proteomics studies identified only about 50% of its theoretical protein count. Here we combined several hundred MS measurements to obtain a comprehensive map of the proteome, phosphoproteome and acetylome of B. subtilis grown at 37 °C in minimal medium. We covered 75% of the theoretical proteome (3,159 proteins), detected 1,085 phosphorylation and 4,893 lysine acetylation sites and performed a systematic bioinformatic characterization of the obtained data. A subset of analyzed MS files allowed us to reconstruct a network of Hanks-type protein kinases, Ser/Thr/Tyr phosphatases and their substrates. We applied genomic phylostratigraphy to gauge the evolutionary age of B. subtilis protein classes and revealed that protein modifications were present on the oldest bacterial proteins. Finally, we performed a proteogenomic analysis by mapping all MS spectra onto a six-frame translation of B. subtilis genome and found evidence for 19 novel ORFs. We provide the most extensive overview of the proteome and post-translational modifications for B. subtilis to date, with insights into functional annotation and evolutionary aspects of the B. subtilis genome.
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44
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Keen EC, Dantas G. Close Encounters of Three Kinds: Bacteriophages, Commensal Bacteria, and Host Immunity. Trends Microbiol 2018; 26:943-954. [PMID: 29909042 PMCID: PMC6436384 DOI: 10.1016/j.tim.2018.05.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/08/2018] [Accepted: 05/17/2018] [Indexed: 12/22/2022]
Abstract
Recent years have witnessed an explosion of interest in the human microbiota. Although commensal bacteria have dominated research efforts to date, mounting evidence suggests that endogenous viral populations (the 'virome') play key roles in basic human physiology. The most numerous constituents of the human virome are not eukaryotic viruses but rather bacteriophages, viruses that infect bacteria. Here, we review phages' interactions with their immediate (prokaryotic) and extended (eukaryotic) hosts and with each other, with a particular emphasis on the temperate phages and prophages which dominate the human virome. We also discuss key outstanding questions in this emerging field and emphasize the urgent need for functional studies in animal models to complement previous in vitro work and current computational approaches.
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Affiliation(s)
- Eric C Keen
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA.
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA; Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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45
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Abstract
Serine integrases catalyze precise rearrangement of DNA through site-specific recombination of small sequences of DNA called attachment (att) sites. Unlike other site-specific recombinases, the recombination reaction driven by serine integrases is highly directional and can only be reversed in the presence of an accessory protein called a recombination directionality factor (RDF). The ability to control reaction directionality has led to the development of serine integrases as tools for controlled rearrangement and modification of DNA in synthetic biology, gene therapy, and biotechnology. This review discusses recent advances in serine integrase technologies focusing on their applications in genome engineering, DNA assembly, and logic and data storage devices.
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Affiliation(s)
- Christine A. Merrick
- School
of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum
Brown Road, Edinburgh EH9
3FF, U.K
| | - Jia Zhao
- Novo
Nordisk (China) Pharmaceuticals Co., Ltd., Lei Shing Hong Center, Guangshunnan Avenue, Beijing 100102, China
| | - Susan J. Rosser
- School
of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum
Brown Road, Edinburgh EH9
3FF, U.K
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46
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Brito PH, Chevreux B, Serra CR, Schyns G, Henriques AO, Pereira-Leal JB. Genetic Competence Drives Genome Diversity in Bacillus subtilis. Genome Biol Evol 2018; 10:108-124. [PMID: 29272410 PMCID: PMC5765554 DOI: 10.1093/gbe/evx270] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2017] [Indexed: 12/18/2022] Open
Abstract
Prokaryote genomes are the result of a dynamic flux of genes, with increases achieved via horizontal gene transfer and reductions occurring through gene loss. The ecological and selective forces that drive this genomic flexibility vary across species. Bacillus subtilis is a naturally competent bacterium that occupies various environments, including plant-associated, soil, and marine niches, and the gut of both invertebrates and vertebrates. Here, we quantify the genomic diversity of B. subtilis and infer the genome dynamics that explain the high genetic and phenotypic diversity observed. Phylogenomic and comparative genomic analyses of 42 B. subtilis genomes uncover a remarkable genome diversity that translates into a core genome of 1,659 genes and an asymptotic pangenome growth rate of 57 new genes per new genome added. This diversity is due to a large proportion of low-frequency genes that are acquired from closely related species. We find no gene-loss bias among wild isolates, which explains why the cloud genome, 43% of the species pangenome, represents only a small proportion of each genome. We show that B. subtilis can acquire xenologous copies of core genes that propagate laterally among strains within a niche. While not excluding the contributions of other mechanisms, our results strongly suggest a process of gene acquisition that is largely driven by competence, where the long-term maintenance of acquired genes depends on local and global fitness effects. This competence-driven genomic diversity provides B. subtilis with its generalist character, enabling it to occupy a wide range of ecological niches and cycle through them.
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Affiliation(s)
- Patrícia H Brito
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Nova Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Portugal
| | - Bastien Chevreux
- DSM Nutritional Products, Ltd., 60 Westview street, Lexington MA, USA
| | - Cláudia R Serra
- Instituto de Tecnologia Química e Biológica, Oeiras, Portugal
| | - Ghislain Schyns
- DSM Nutritional Products, Ltd., 60 Westview street, Lexington MA, USA
| | | | - José B Pereira-Leal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Ophiomics—Precision Medicine, Lisbon, Portugal
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47
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Abe K, Takamatsu T, Sato T. Mechanism of bacterial gene rearrangement: SprA-catalyzed precise DNA recombination and its directionality control by SprB ensure the gene rearrangement and stable expression of spsM during sporulation in Bacillus subtilis. Nucleic Acids Res 2017; 45:6669-6683. [PMID: 28535266 PMCID: PMC5499854 DOI: 10.1093/nar/gkx466] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/12/2017] [Indexed: 12/17/2022] Open
Abstract
A sporulation-specific gene, spsM, is disrupted by an active prophage, SPβ, in the genome of Bacillus subtilis. SPβ excision is required for two critical steps: the onset of the phage lytic cycle and the reconstitution of the spsM-coding frame during sporulation. Our in vitro study demonstrated that SprA, a serine-type integrase, catalyzed integration and excision reactions between attP of SPβ and attB within spsM, while SprB, a recombination directionality factor, was necessary only for the excision between attL and attR in the SPβ lysogenic chromosome. DNA recombination occurred at the center of the short inverted repeat motif in the unique conserved 16 bp sequence among the att sites (5΄-ACAGATAA/AGCTGTAT-3΄; slash, breakpoint; underlines, inverted repeat), where SprA produced the 3΄-overhanging AA and TT dinucleotides for rejoining the DNA ends through base-pairing. Electrophoretic mobility shift assay showed that SprB promoted synapsis of SprA subunits bound to the two target sites during excision but impaired it during integration. In vivo data demonstrated that sprB expression that lasts until the late stage of sporulation is crucial for stable expression of reconstituted spsM without reintegration of the SPβ prophage. These results present a deeper understanding of the mechanism of the prophage-mediated bacterial gene regulatory system.
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Affiliation(s)
- Kimihiro Abe
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo 184-0003, Japan
| | - Takuo Takamatsu
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo 184-8584, Japan
| | - Tsutomu Sato
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo 184-0003, Japan.,Department of Frontier Bioscience, Hosei University, Koganei, Tokyo 184-8584, Japan
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48
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Abe K, Shimizu SY, Tsuda S, Sato T. A novel non prophage(-like) gene-intervening element within gerE that is reconstituted during sporulation in Bacillus cereus ATCC10987. Sci Rep 2017; 7:11426. [PMID: 28900282 PMCID: PMC5595907 DOI: 10.1038/s41598-017-11796-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/30/2017] [Indexed: 11/10/2022] Open
Abstract
Gene rearrangement is a widely-shared phenomenon in spore forming bacteria, in which prophage(-like) elements interrupting sporulation-specific genes are excised from the host genome to reconstitute the intact gene. Here, we report a novel class of gene-intervening elements, named gin, inserted in the 225 bp gerE-coding region of the B. cereus ATCC10987 genome, which generates a sporulation-specific rearrangement. gin has no phage-related genes and possesses three site-specific recombinase genes; girA, girB, and girC. We demonstrated that the gerE rearrangement occurs at the middle stage of sporulation, in which site-specific DNA recombination took place within the 9 bp consensus sequence flanking the disrupted gerE segments. Deletion analysis of gin uncovered that GirC and an additional factor, GirX, are responsible for gerE reconstitution. Involvement of GirC and GirX in DNA recombination was confirmed by an in vitro recombination assay. These results broaden the definition of the sporulation-specific gene rearrangement phenomenon: gene-intervening elements are not limited to phage DNA but may include non-viral genetic elements that carry a developmentally-regulated site-specific recombination system.
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Affiliation(s)
- Kimihiro Abe
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
| | - Shin-Ya Shimizu
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Shuhei Tsuda
- Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan
| | - Tsutomu Sato
- Research Center of Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan. .,Department of Frontier Bioscience, Hosei University, Koganei, Tokyo, Japan.
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49
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Abstract
Spores of Clostridiales and Bacillales are encased in a complex series of concentric shells that provide protection, facilitate germination, and mediate interactions with the environment. Analysis of diverse spore-forming species by thin-section transmission electron microscopy reveals that the number and morphology of these encasing shells vary greatly. In some species, they appear to be composed of a small number of discrete layers. In other species, they can comprise multiple, morphologically complex layers. In addition, spore surfaces can possess elaborate appendages. For all their variability, there is a consistent architecture to the layers encasing the spore. A hallmark of all Clostridiales and Bacillales spores is the cortex, a layer made of peptidoglycan. In close association with the cortex, all species examined possess, at a minimum, a series of proteinaceous layers, called the coat. In some species, including Bacillus subtilis, only the coat is present. In other species, including Bacillus anthracis, an additional layer, called the exosporium, surrounds the coat. Our goals here are to review the present understanding of the structure, composition, assembly, and functions of the coat, primarily in the model organism B. subtilis, but also in the small but growing number of other spore-forming species where new data are showing that there is much to be learned beyond the relatively well-developed basis of knowledge in B. subtilis. To help summarize this large field and define future directions for research, we will focus on key findings in recent years.
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Genome-Wide Analysis of ResD, NsrR, and Fur Binding in Bacillus subtilis during Anaerobic Fermentative Growth by In Vivo Footprinting. J Bacteriol 2017; 199:JB.00086-17. [PMID: 28439033 DOI: 10.1128/jb.00086-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 04/13/2017] [Indexed: 12/20/2022] Open
Abstract
Upon oxygen limitation, the Bacillus subtilis ResE sensor kinase and its cognate ResD response regulator play primary roles in the transcriptional activation of genes functioning in anaerobic respiration. The nitric oxide (NO)-sensitive NsrR repressor controls transcription to support nitrate respiration. In addition, the ferric uptake repressor (Fur) can modulate transcription under anaerobic conditions. However, whether these controls are direct or indirect has been investigated only in a gene-specific manner. To gain a genomic view of anaerobic gene regulation, we determined the genome-wide in vivo DNA binding of ResD, NsrR, and Fur transcription factors (TFs) using in situ DNase I footprinting combined with chromatin affinity precipitation sequencing (ChAP-seq; genome footprinting by high-throughput sequencing [GeF-seq]). A significant number of sites were targets of ResD and NsrR, and a majority of them were also bound by Fur. The binding of multiple TFs to overlapping targets affected each individual TF's binding, which led to combinatorial transcriptional control. ResD bound to both the promoters and the coding regions of genes under its positive control. Other genes showing enrichment of ResD at only the promoter regions are targets of direct ResD-dependent repression or antirepression. The results support previous findings of ResD as an RNA polymerase (RNAP)-binding protein and indicated that ResD can associate with the transcription elongation complex. The data set allowed us to reexamine consensus sequence motifs of Fur, ResD, and NsrR and uncovered evidence that multiple TGW (where W is A or T) sequences surrounded by an A- and T-rich sequence are often found at sites where all three TFs competitively bind.IMPORTANCE Bacteria encounter oxygen fluctuation in their natural environment as well as in host organisms. Hence, understanding how bacteria respond to oxygen limitation will impact environmental and human health. ResD, NsrR, and Fur control transcription under anaerobic conditions. This work using in situ DNase I footprinting uncovered the genome-wide binding profile of the three transcription factors (TFs). Binding of the TFs is often competitive or cooperative depending on the promoters and the presence of other TFs, indicating that transcriptional regulation by multiple TFs is much more complex than we originally thought. The results from this study provide a more complete picture of anaerobic gene regulation governed by ResD, NsrR, and Fur and contribute to our further understanding of anaerobic physiology.
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