1
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Richter A, Blei F, Hu G, Schwitalla JW, Lozano-Andrade CN, Xie J, Jarmusch SA, Wibowo M, Kjeldgaard B, Surabhi S, Xu X, Jautzus T, Phippen CBW, Tyc O, Arentshorst M, Wang Y, Garbeva P, Larsen TO, Ram AFJ, van den Hondel CAM, Maróti G, Kovács ÁT. Enhanced surface colonisation and competition during bacterial adaptation to a fungus. Nat Commun 2024; 15:4486. [PMID: 38802389 PMCID: PMC11130161 DOI: 10.1038/s41467-024-48812-1] [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: 06/05/2023] [Accepted: 05/13/2024] [Indexed: 05/29/2024] Open
Abstract
Bacterial-fungal interactions influence microbial community performance of most ecosystems and elicit specific microbial behaviours, including stimulating specialised metabolite production. Here, we use a co-culture experimental evolution approach to investigate bacterial adaptation to the presence of a fungus, using a simple model of bacterial-fungal interactions encompassing the bacterium Bacillus subtilis and the fungus Aspergillus niger. We find in one evolving population that B. subtilis was selected for enhanced production of the lipopeptide surfactin and accelerated surface spreading ability, leading to inhibition of fungal expansion and acidification of the environment. These phenotypes were explained by specific mutations in the DegS-DegU two-component system. In the presence of surfactin, fungal hyphae exhibited bulging cells with delocalised secretory vesicles possibly provoking an RlmA-dependent cell wall stress. Thus, our results indicate that the presence of the fungus selects for increased surfactin production, which inhibits fungal growth and facilitates the competitive success of the bacterium.
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Affiliation(s)
- Anne Richter
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Felix Blei
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
- Department Pharmaceutical Microbiology, Hans-Knöll-Institute, Friedrich-Schiller-Universität, Jena, Germany
| | - Guohai Hu
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
- BGI-Shenzhen, Shenzhen, China
- Shenzhen Key Laboratory of Environmental Microbial Genomics and Application, BGI-Shenzhen, Shenzhen, China
| | - Jan W Schwitalla
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Carlos N Lozano-Andrade
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Jiyu Xie
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Scott A Jarmusch
- Natural Product Discovery Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Mario Wibowo
- Natural Product Discovery Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research, Singapore, Republic of Singapore
| | - Bodil Kjeldgaard
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Surabhi Surabhi
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Xinming Xu
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Theresa Jautzus
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Christopher B W Phippen
- Natural Product Discovery Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Olaf Tyc
- Netherlands Institute of Ecology, Wageningen, The Netherlands
- Department of Internal Medicine I, Goethe University Hospital, Frankfurt, Germany
| | - Mark Arentshorst
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Yue Wang
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
- BGI-Shenzhen, Shenzhen, China
| | - Paolina Garbeva
- Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Thomas Ostenfeld Larsen
- Natural Product Discovery Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Arthur F J Ram
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | | | - Gergely Maróti
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark.
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany.
- Institute of Biology, Leiden University, Leiden, The Netherlands.
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2
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Wu YC, Yu CW, Chiu JY, Chiang YH, Mitsuda N, Yen XC, Huang TP, Chang TF, Yen CJ, Guo WJ. The AT-hook protein AHL29 promotes Bacillus subtilis colonization by suppressing SWEET2-mediated sugar retrieval in Arabidopsis roots. PLANT, CELL & ENVIRONMENT 2024; 47:1084-1098. [PMID: 38037476 DOI: 10.1111/pce.14779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 11/03/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
Beneficial Bacillus subtilis (BS) symbiosis could combat root pathogenesis, but it relies on root-secreted sugars. Understanding the molecular control of sugar flux during colonization would benefit biocontrol applications. The SWEET (Sugar Will Eventually Be Exported Transporter) uniporter regulates microbe-induced sugar secretion from roots; thus, its homologs may modulate sugar distribution upon BS colonization. Quantitative polymerase chain reaction revealed that gene transcripts of SWEET2, but not SWEET16 and 17, were significantly induced in seedling roots after 12 h of BS inoculation. Particularly, SWEET2-β-glucuronidase fusion proteins accumulated in the apical mature zone where BS abundantly colonized. Yet, enhanced BS colonization in sweet2 mutant roots suggested a specific role for SWEET2 to constrain BS propagation, probably by limiting hexose secretion. By employing yeast one-hybrid screening and ectopic expression in Arabidopsis protoplasts, the transcription factor AHL29 was identified to function as a repressor of SWEET2 expression through the AT-hook motif. Repression occurred despite immunity signals. Additionally, enhanced SWEET2 expression and reduced colonies were specifically detected in roots of BS-colonized ahl29 mutant. Taken together, we propose that BS colonization may activate repression of AHL29 on SWEET2 transcription that would be enhanced by immunity signals, thereby maintaining adequate sugar secretion for a beneficial Bacillus association.
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Affiliation(s)
- Yun-Chien Wu
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Chien-Wen Yu
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Jo-Yu Chiu
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Yu-Hsuan Chiang
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Nobutaka Mitsuda
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Xu-Chen Yen
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan ROC
| | - Tzu-Pi Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan ROC
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, Taiwan ROC
- Master and Doctoral Degree Program in Plant Health Care, Academy of Circular Economy, National Chung Hsing University, Nantou, Taiwan ROC
| | - Tzu-Fang Chang
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Cen-Jie Yen
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
| | - Woei-Jiun Guo
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan, Taiwan ROC
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3
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Novak V, Andeer PF, Bowen BP, Ding Y, Zhalnina K, Hofmockel KS, Tomaka C, Harwood TV, van Winden MCM, Golini AN, Kosina SM, Northen TR. Reproducible growth of Brachypodium in EcoFAB 2.0 reveals that nitrogen form and starvation modulate root exudation. SCIENCE ADVANCES 2024; 10:eadg7888. [PMID: 38170767 PMCID: PMC10776018 DOI: 10.1126/sciadv.adg7888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 11/20/2023] [Indexed: 01/05/2024]
Abstract
Understanding plant-microbe interactions requires examination of root exudation under nutrient stress using standardized and reproducible experimental systems. We grew Brachypodium distachyon hydroponically in fabricated ecosystem devices (EcoFAB 2.0) under three inorganic nitrogen forms (nitrate, ammonium, and ammonium nitrate), followed by nitrogen starvation. Analyses of exudates with liquid chromatography-tandem mass spectrometry, biomass, medium pH, and nitrogen uptake showed EcoFAB 2.0's low intratreatment data variability. Furthermore, the three inorganic nitrogen forms caused differential exudation, generalized by abundant amino acids-peptides and alkaloids. Comparatively, nitrogen deficiency decreased nitrogen-containing compounds but increased shikimates-phenylpropanoids. Subsequent bioassays with two shikimates-phenylpropanoids (shikimic and p-coumaric acids) on soil bacteria or Brachypodium seedlings revealed their distinct capacity to regulate both bacterial and plant growth. Our results suggest that (i) Brachypodium alters exudation in response to nitrogen status, which can affect rhizobacterial growth, and (ii) EcoFAB 2.0 is a valuable standardized plant research tool.
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Affiliation(s)
- Vlastimil Novak
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Peter F. Andeer
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Benjamin P. Bowen
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Yezhang Ding
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kateryna Zhalnina
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kirsten S. Hofmockel
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA
- Department of Agronomy, Iowa State University, Ames, IA 50011, USA
| | - Connor Tomaka
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Thomas V. Harwood
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Amber N. Golini
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Suzanne M. Kosina
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Trent R. Northen
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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4
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Sartor F, Xu X, Popp T, Dodd AN, Kovács ÁT, Merrow M. The circadian clock of the bacterium B. subtilis evokes properties of complex, multicellular circadian systems. SCIENCE ADVANCES 2023; 9:eadh1308. [PMID: 37540742 PMCID: PMC10403212 DOI: 10.1126/sciadv.adh1308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 07/05/2023] [Indexed: 08/06/2023]
Abstract
Circadian clocks are pervasive throughout nature, yet only recently has this adaptive regulatory program been described in nonphotosynthetic bacteria. Here, we describe an inherent complexity in the Bacillus subtilis circadian clock. We find that B. subtilis entrains to blue and red light and that circadian entrainment is separable from masking through fluence titration and frequency demultiplication protocols. We identify circadian rhythmicity in constant light, consistent with the Aschoff's rule, and entrainment aftereffects, both of which are properties described for eukaryotic circadian clocks. We report that circadian rhythms occur in wild isolates of this prokaryote, thus establishing them as a general property of this species, and that its circadian system responds to the environment in a complex fashion that is consistent with multicellular eukaryotic circadian systems.
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Affiliation(s)
- Francesca Sartor
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Munich, Germany
| | - Xinming Xu
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Tanja Popp
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Munich, Germany
| | - Antony N. Dodd
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Ákos T. Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Martha Merrow
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Munich, Germany
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5
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Rosazza T, Eigentler L, Earl C, Davidson FA, Stanley‐Wall NR. Bacillus subtilis extracellular protease production incurs a context-dependent cost. Mol Microbiol 2023; 120:105-121. [PMID: 37380434 PMCID: PMC10952608 DOI: 10.1111/mmi.15110] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/07/2023] [Accepted: 06/08/2023] [Indexed: 06/30/2023]
Abstract
Microbes encounter a wide range of polymeric nutrient sources in various environmental settings, which require processing to facilitate growth. Bacillus subtilis, a bacterium found in the rhizosphere and broader soil environment, is highly adaptable and resilient due to its ability to utilise diverse sources of carbon and nitrogen. Here, we explore the role of extracellular proteases in supporting growth and assess the cost associated with their production. We provide evidence of the essentiality of extracellular proteases when B. subtilis is provided with an abundant, but polymeric nutrient source and demonstrate the extracellular proteases as a shared public good that can operate over a distance. We show that B. subtilis is subjected to a public good dilemma, specifically in the context of growth sustained by the digestion of a polymeric food source. Furthermore, using mathematical simulations, we uncover that this selectively enforced dilemma is driven by the relative cost of producing the public good. Collectively, our findings reveal how bacteria can survive in environments that vary in terms of immediate nutrient accessibility and the consequent impact on the population composition. These findings enhance our fundamental understanding of how bacteria respond to diverse environments, which has importance to contexts ranging from survival in the soil to infection and pathogenesis scenarios.
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Affiliation(s)
- Thibault Rosazza
- Division of Molecular Microbiology, School of Life ScienceUniversity of DundeeDundeeUK
| | - Lukas Eigentler
- Division of Molecular Microbiology, School of Life ScienceUniversity of DundeeDundeeUK
- Mathematics, School of Science and EngineeringUniversity of DundeeDundeeUK
- Present address:
Evolutionary Biology DepartmentUniversität BielefeldKonsequenz 45Bielefeld33615Germany
| | - Chris Earl
- Division of Molecular Microbiology, School of Life ScienceUniversity of DundeeDundeeUK
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6
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Bremer E, Calteau A, Danchin A, Harwood C, Helmann JD, Médigue C, Palsson BO, Sekowska A, Vallenet D, Zuniga A, Zuniga C. A model industrial workhorse:
Bacillus subtilis
strain 168 and its genome after a quarter of a century. Microb Biotechnol 2023; 16:1203-1231. [PMID: 37002859 DOI: 10.1111/1751-7915.14257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 03/20/2023] [Indexed: 04/04/2023] Open
Abstract
The vast majority of genomic sequences are automatically annotated using various software programs. The accuracy of these annotations depends heavily on the very few manual annotation efforts that combine verified experimental data with genomic sequences from model organisms. Here, we summarize the updated functional annotation of Bacillus subtilis strain 168, a quarter century after its genome sequence was first made public. Since the last such effort 5 years ago, 1168 genetic functions have been updated, allowing the construction of a new metabolic model of this organism of environmental and industrial interest. The emphasis in this review is on new metabolic insights, the role of metals in metabolism and macromolecule biosynthesis, functions involved in biofilm formation, features controlling cell growth, and finally, protein agents that allow class discrimination, thus allowing maintenance management, and accuracy of all cell processes. New 'genomic objects' and an extensive updated literature review have been included for the sequence, now available at the International Nucleotide Sequence Database Collaboration (INSDC: AccNum AL009126.4).
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Affiliation(s)
- Erhard Bremer
- Department of Biology, Laboratory for Microbiology and Center for Synthetic Microbiology (SYNMIKRO) Philipps‐University Marburg Marburg Germany
| | - Alexandra Calteau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut de Biologie François Jacob Université d'Évry, Université Paris‐Saclay, CNRS Évry France
| | - Antoine Danchin
- School of Biomedical Sciences, Li KaShing Faculty of Medicine Hong Kong University Pokfulam SAR Hong Kong China
| | - Colin Harwood
- Centre for Bacterial Cell Biology, Biosciences Institute Newcastle University Baddiley Clark Building Newcastle upon Tyne UK
| | - John D. Helmann
- Department of Microbiology Cornell University Ithaca New York USA
| | - Claudine Médigue
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut de Biologie François Jacob Université d'Évry, Université Paris‐Saclay, CNRS Évry France
| | - Bernhard O. Palsson
- Department of Bioengineering University of California San Diego La Jolla USA
| | | | - David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut de Biologie François Jacob Université d'Évry, Université Paris‐Saclay, CNRS Évry France
| | - Abril Zuniga
- Department of Biology San Diego State University San Diego California USA
| | - Cristal Zuniga
- Bioinformatics and Medical Informatics Graduate Program San Diego State University San Diego California USA
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7
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Podnar E, Erega A, Danevčič T, Kovačec E, Lories B, Steenackers H, Mandic-Mulec I. Nutrient Availability and Biofilm Polysaccharide Shape the Bacillaene-Dependent Antagonism of Bacillus subtilis against Salmonella Typhimurium. Microbiol Spectr 2022; 10:e0183622. [PMID: 36342318 PMCID: PMC9769773 DOI: 10.1128/spectrum.01836-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Salmonella enterica is one of the most common foodborne pathogens and, due to the spread of antibiotic resistance, new antimicrobial strategies are urgently needed to control it. In this study, we explored the probiotic potential of Bacillus subtilis PS-216 and elucidated the mechanisms that underlie the interactions between this soil isolate and the model pathogenic strain S. Typhimurium SL1344. The results reveal that B. subtilis PS-216 inhibits the growth and biofilm formation of S. Typhimurium through the production of the pks cluster-dependent polyketide bacillaene. The presence of S. Typhimurium enhanced the activity of the PpksC promoter that controls bacillaene production, suggesting that B. subtilis senses and responds to Salmonella. The level of Salmonella inhibition, overall PpksC activity, and PpksC induction by Salmonella were all higher in nutrient-rich conditions than in nutrient-depleted conditions. Although eliminating the extracellular polysaccharide production of B. subtilis via deletion of the epsA-O operon had no significant effect on inhibitory activity against Salmonella in nutrient-rich conditions, this deletion mutant showed an enhanced antagonism against Salmonella in nutrient-depleted conditions, revealing an intricate relationship between exopolysaccharide production, nutrient availability, and bacillaene synthesis. Overall, this work provides evidence on the regulatory role of nutrient availability, sensing of the competitor, and EpsA-O polysaccharide in the social outcome of bacillaene-dependent competition between B. subtilis and S. Typhimurium. IMPORTANCE Probiotic bacteria represent an alternative for controlling foodborne disease caused by Salmonella enterica, which constitutes a serious concern during food production due to its antibiotic resistance and resilience to environmental stress. Bacillus subtilis is gaining popularity as a probiotic, but its behavior in biofilms with pathogens such as Salmonella remains to be elucidated. Here, we show that the antagonism of B. subtilis is mediated by the polyketide bacillaene and that the production of bacillaene is a highly dynamic trait which depends on environmental factors such as nutrient availability and the presence of competitors. Moreover, the production of extracellular polysaccharides by B. subtilis further alters the influence of these factors. Hence, this work highlights the inhibitory effect of B. subtilis, which is condition-dependent, and the importance of evaluating probiotic strains under conditions relevant to the intended use.
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Affiliation(s)
- Eli Podnar
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Andi Erega
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Tjaša Danevčič
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Kovačec
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Bram Lories
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Hans Steenackers
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Ines Mandic-Mulec
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- Chair of Microprocess Engineering and Technology (COMPETE), University of Ljubljana, Ljubljana, Slovenia
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8
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Fessia A, Sartori M, García D, Fernández L, Ponzio R, Barros G, Nesci A. In vitro studies of biofilm-forming Bacillus strains, biocontrol agents isolated from the maize phyllosphere. Biofilm 2022; 4:100097. [PMID: 36504526 PMCID: PMC9731887 DOI: 10.1016/j.bioflm.2022.100097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/08/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022] Open
Abstract
We aimed to assess how biofilm formation by three Bacillus isolates was affected by changes in temperature, water potential, growth media, time, and the combinations between these factors. The strains had been selected as potential biological control agents (BCAs) in earlier studies, and they were identified as B. subtilis and B. velezensis spp. through 16 rRNA sequencing and MALDI-TOF MS. Maize leaves (ML) were used as one of the growth media, since they made it possible to simulate the nutrient content in the maize phyllosphere, from which the bacteria were originally isolated. The strains were able to form biofilm both in ML and biofilm-inducing MSgg after 24, 48, and 72 h. Biofilm development in the form of pellicles and architecturally complex colonies varied morphologically from one strain to another and depended on the conditions mentioned above. In all cases, colonies and pellicles were less complex when both temperature and water potential were lower. Scanning electron microscopy (SEM) revealed that changing levels of complexity in pellicles were correlated with those in colonies. Statistical analyses found that the quantification of biofilm produced by the isolates was influenced by all the conditions tested. In terms of motility (which may contribute to biofilm formation), swimming and swarming were possible for all strains in 0.3 and 0.7% agar, respectively. A more in-depth understanding of how abiotic factors influence biofilm formation can contribute to a more effective use of these biocontrol strains against pathogens in the maize phyllosphere.
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Affiliation(s)
- Aluminé Fessia
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina,Corresponding author. Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina.
| | - Melina Sartori
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Daiana García
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Luciana Fernández
- Departamento de Física, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CONICET, X5804BYA, Río Cuarto, Argentina,Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Rodrigo Ponzio
- Departamento de Física, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CONICET, X5804BYA, Río Cuarto, Argentina,Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Germán Barros
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Andrea Nesci
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
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9
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Engineered endosymbionts that alter mammalian cell surface marker, cytokine and chemokine expression. Commun Biol 2022; 5:888. [PMID: 36042261 PMCID: PMC9427783 DOI: 10.1038/s42003-022-03851-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022] Open
Abstract
Developing modular tools that direct mammalian cell function and activity through controlled delivery of essential regulators would improve methods of guiding tissue regeneration, enhancing cellular-based therapeutics and modulating immune responses. To address this challenge, Bacillus subtilis was developed as a chassis organism for engineered endosymbionts (EES) that escape phagosome destruction, reside in the cytoplasm of mammalian cells, and secrete proteins that are transported to the nucleus to impact host cell response and function. Two synthetic operons encoding either the mammalian transcription factors Stat-1 and Klf6 or Klf4 and Gata-3 were recombined into the genome of B. subtilis expressing listeriolysin O (LLO) from Listeria monocytogenes and expressed from regulated promoters. Controlled expression of the mammalian proteins from B. subtilis LLO in the cytoplasm of J774A.1 macrophage/monocyte cells altered surface marker, cytokine and chemokine expression. Modulation of host cell fates displayed some expected patterns towards anti- or pro-inflammatory phenotypes by each of the distinct transcription factor pairs with further demonstration of complex regulation caused by a combination of the EES interaction and transcription factors. Expressing mammalian transcription factors from engineered intracellular B. subtilis as engineered endosymbionts comprises a new tool for directing host cell gene expression for therapeutic and research purposes. The establishment of non-pathogenic engineered endosymbionts through B. subtilis is presented, with the aim of delivering mammalian transcription factors to the host cell for therapeutics and research.
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Xu S, Cao Q, Liu Z, Chen J, Yan P, Li B, Xu Y. Transcriptomic Analysis Reveals the Role of tmRNA on Biofilm Formation in Bacillus subtilis. Microorganisms 2022; 10:microorganisms10071338. [PMID: 35889057 PMCID: PMC9319509 DOI: 10.3390/microorganisms10071338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 11/16/2022] Open
Abstract
Bacillus strains are widely distributed in terrestrial and marine environments, and some of them are used as biocontrol organisms for their biofilm-formation ability. In Bacillus subtilis, biofilm formation is fine-tuned by a complex network, a clear understanding of which still requires study. In bacteria, tmRNA, encoded by the ssrA gene, catalyzes trans-translation that can rescue ribosomes stalled on mRNA transcripts lacking a functional stop codon. tmRNA also affects physiological bioprocesses in some bacteria. In this study, we constructed a ssrA mutant in B. subtilis and found that the biofilm formation in the ssrA mutant was largely impaired. Moreover, we isolated a biofilm-formation suppressor of ssrA, in which the biofilm formation was restored to a level even stronger than that in the wild type. We further performed RNAseq assays with the wild type, ssrA mutant, and suppressor of ssrA for comparisons of their transcriptomes. By analyzing the transcriptomic data, we predicted the possible functions of some differentially expressed genes (DEGs) in the tmRNA regulation of biofilm formation in B. subtilis. Finally, we found that the overexpression of two DEGs, acoA and yhjR, could restore the biofilm formation in the ssrA mutant, indicating that AcoA and YhjR were immediate regulators involved in the tmRNA regulatory web controlling biofilm formation in B. subtilis. Our data can improve the knowledge about the molecular network involved in Bacillus biofilm formation and provide new targets for manipulation of Bacillus biofilms for future investigation.
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Affiliation(s)
- Shanshan Xu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Qianqian Cao
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
| | - Zengzhi Liu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Junpeng Chen
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
| | - Peiguang Yan
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Bingyu Li
- Guangdong Key Laboratory for Genome Stability and Disease Prevention, Health Science Center, Shenzhen University, Shenzhen 518055, China
- Correspondence: (B.L.); (Y.X.)
| | - Ying Xu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- Correspondence: (B.L.); (Y.X.)
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Bremer E, Hoffmann T, Dempwolff F, Bedrunka P, Bange G. The many faces of the unusual biofilm activator RemA. Bioessays 2022; 44:e2200009. [PMID: 35289951 DOI: 10.1002/bies.202200009] [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: 01/11/2022] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 11/08/2022]
Abstract
Biofilms can be viewed as tissue-like structures in which microorganisms are organized in a spatial and functional sophisticated manner. Biofilm formation requires the orchestration of a highly integrated network of regulatory proteins to establish cell differentiation and production of a complex extracellular matrix. Here, we discuss the role of the essential Bacillus subtilis biofilm activator RemA. Despite intense research on biofilms, RemA is a largely underappreciated regulatory protein. RemA forms donut-shaped octamers with the potential to assemble into dimeric superstructures. The presumed DNA-binding mode suggests that RemA organizes its target DNA into nucleosome-like structures, which are the basis for its role as transcriptional activator. We discuss how RemA affects gene expression in the context of biofilm formation, and its regulatory interplay with established components of the biofilm regulatory network, such as SinR, SinI, SlrR, and SlrA. We emphasize the additional role of RemA played in nitrogen metabolism and osmotic-stress adjustment.
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Affiliation(s)
- Erhard Bremer
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Tamara Hoffmann
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Felix Dempwolff
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Patricia Bedrunka
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany.,Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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12
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Bacillus velezensis stimulates resident rhizosphere Pseudomonas stutzeri for plant health through metabolic interactions. THE ISME JOURNAL 2022; 16:774-787. [PMID: 34593997 PMCID: PMC8483172 DOI: 10.1038/s41396-021-01125-3] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023]
Abstract
Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by efficient colonization; however, the metabolite exchanges between inoculants and resident bacteria are rarely studied, particularly in the rhizosphere. Here, we used bioinformatic, genetic, transcriptomic, and metabonomic analyses to uncover syntrophic cooperation between inoculant (Bacillus velezensis SQR9) and plant-beneficial indigenous Pseudomonas stutzeri in the cucumber rhizosphere. We found that the synergistic interaction of these two species is highly environmental dependent, the emergence of syntrophic cooperation was only evident in a static nutrient-rich niche, such as pellicle biofilm in addition to the rhizosphere. Our results identified branched-chain amino acids (BCAAs) biosynthesis pathways are involved in syntrophic cooperation. Genome-scale metabolic modeling and metabolic profiling also demonstrated metabolic facilitation among the bacterial strains. In addition, biofilm matrix components from Bacillus were essential for the interaction. Importantly, the two-species consortium promoted plant growth and helped plants alleviate salt stress. In summary, we propose a mechanism in which synergic interactions between a biocontrol bacterium and a partner species promote plant health.
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13
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Drost M, Diamanti E, Fuhrmann K, Goes A, Shams A, Haupenthal J, Koch M, Hirsch AKH, Fuhrmann G. Bacteriomimetic Liposomes Improve Antibiotic Activity of a Novel Energy-Coupling Factor Transporter Inhibitor. Pharmaceutics 2021; 14:4. [PMID: 35056900 PMCID: PMC8779172 DOI: 10.3390/pharmaceutics14010004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/10/2021] [Accepted: 12/16/2021] [Indexed: 11/21/2022] Open
Abstract
Liposomes have been studied for decades as nanoparticulate drug delivery systems for cytostatics, and more recently, for antibiotics. Such nanoantibiotics show improved antibacterial efficacy compared to the free drug and can be effective despite bacterial recalcitrance. In this work, we present a loading method of bacteriomimetic liposomes for a novel, hydrophobic compound (HIPS5031) inhibiting energy-coupling factor transporters (ECF transporters), an underexplored antimicrobial target. The liposomes were composed of DOPG (18:1 (Δ9-cis) phosphatidylglycerol) and CL (cardiolipin), resembling the cell membrane of Gram-positive Staphylococcus aureus and Streptococcus pneumoniae, and enriched with cholesterol (Chol). The size and polydispersity of the DOPG/CL/± Chol liposomes remained stable over 8 weeks when stored at 4 °C. Loading of the ECF transporter inhibitor was achieved by thin film hydration and led to a high encapsulation efficiency of 33.19% ± 9.5% into the DOPG/CL/Chol liposomes compared to the phosphatidylcholine liposomes (DMPC/DPPC). Bacterial growth inhibition assays on the model organism Bacillus subtilis revealed liposomal HIPS5031 as superior to the free drug, showing a 3.5-fold reduction in CFU/mL at a concentration of 9.64 µM. Liposomal HIPS5031 was also shown to reduce B. subtilis biofilm. Our findings present an explorative basis for bacteriomimetic liposomes as a strategy against drug-resistant pathogens by surpassing the drug-formulation barriers of innovative, yet unfavorably hydrophobic, antibiotics.
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Affiliation(s)
- Menka Drost
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
- Department of Biology, Pharmaceutical Biology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Staudtstr. 5, 91058 Erlangen, Germany
| | - Eleonora Diamanti
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
- Helmholtz International Lab for Anti-Infectives, Campus E8.1, 66123 Saarbrücken, Germany
| | - Kathrin Fuhrmann
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
| | - Adriely Goes
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
| | - Atanaz Shams
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
| | - Jörg Haupenthal
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
| | - Marcus Koch
- INM-Leibniz-Institut für Neue Materialien, Campus D2.2, 66123 Saarbrücken, Germany;
| | - Anna K. H. Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
- Helmholtz International Lab for Anti-Infectives, Campus E8.1, 66123 Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Campus C1.7, 66123 Saarbrücken, Germany
| | - Gregor Fuhrmann
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Campus E8.1, 66123 Saarbrücken, Germany; (M.D.); (E.D.); (K.F.); (A.G.); (A.S.); (J.H.); (A.K.H.H.)
- Department of Biology, Pharmaceutical Biology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Staudtstr. 5, 91058 Erlangen, Germany
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Hayta EN, Rickert CA, Lieleg O. Topography quantifications allow for identifying the contribution of parental strains to physical properties of co-cultured biofilms. Biofilm 2021; 3:100044. [PMID: 33665611 PMCID: PMC7902895 DOI: 10.1016/j.bioflm.2021.100044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
Most biofilm research has so far focused on investigating biofilms generated by single bacterial strains. However, such single-species biofilms are rare in nature where bacteria typically coexist with other microorganisms. Although, from a biological view, the possible interactions occurring between different bacteria are well studied, little is known about what determines the material properties of a multi-species biofilm. Here, we ask how the co-cultivation of two B. subtilis strains affects certain important biofilm properties such as surface topography and wetting behavior. We find that, even though each daughter colony typically resembles one of the parent colonies in terms of morphology and wetting, it nevertheless exhibits a significantly different surface topography. Yet, this difference is only detectable via a quantitative metrological analysis of the biofilm surface. Furthermore, we show that this difference is due to the presence of bacteria belonging to the 'other' parent strain, which does not dominate the biofilm features. The findings presented here may pinpoint new strategies for how biofilms with hybrid properties could be generated from two different bacterial strains. In such engineered biofilms, it might be possible to combine desired properties from two strains by co-cultivation.
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Affiliation(s)
- Elif N. Hayta
- Munich School of Bioengineering and Department of Mechanical Engineering, Technical University of Munich, 85748, Garching, Germany
- Center for Protein Assemblies (CPA), Technical University of Munich, Ernst-Otto-Fischer Straße 8, 85748, Garching, Germany
| | - Carolin A. Rickert
- Munich School of Bioengineering and Department of Mechanical Engineering, Technical University of Munich, 85748, Garching, Germany
- Center for Protein Assemblies (CPA), Technical University of Munich, Ernst-Otto-Fischer Straße 8, 85748, Garching, Germany
| | - Oliver Lieleg
- Munich School of Bioengineering and Department of Mechanical Engineering, Technical University of Munich, 85748, Garching, Germany
- Center for Protein Assemblies (CPA), Technical University of Munich, Ernst-Otto-Fischer Straße 8, 85748, Garching, Germany
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15
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Hoffmann TD, Paine K, Gebhard S. Genetic optimisation of bacteria-induced calcite precipitation in Bacillus subtilis. Microb Cell Fact 2021; 20:214. [PMID: 34794448 PMCID: PMC8600894 DOI: 10.1186/s12934-021-01704-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/06/2021] [Indexed: 11/25/2022] Open
Abstract
Background Microbially induced calcite precipitation (MICP) is an ancient property of bacteria, which has recently gained considerable attention for biotechnological applications. It occurs as a by-product of bacterial metabolism and involves a combination of chemical changes in the extracellular environment, e.g. pH increase, and presence of nucleation sites on the cell surface or extracellular substances produced by the bacteria. However, the molecular mechanisms underpinning MICP and the interplay between the contributing factors remain poorly understood, thus placing barriers to the full biotechnological and synthetic biology exploitation of bacterial biomineralisation. Results In this study, we adopted a bottom-up approach of systematically engineering Bacillus subtilis, which has no detectable intrinsic MICP activity, for biomineralisation. We showed that heterologous production of urease can induce MICP by local increases in extracellular pH, and this can be enhanced by co-expression of urease accessory genes for urea and nickel uptake, depending on environmental conditions. MICP can be strongly enhanced by biofilm-promoting conditions, which appeared to be mainly driven by production of exopolysaccharide, while the protein component of the biofilm matrix was dispensable. Attempts to modulate the cell surface charge of B. subtilis had surprisingly minor effects, and our results suggest this organism may intrinsically have a very negative cell surface, potentially predisposing it for MICP activity. Conclusions Our findings give insights into the molecular mechanisms driving MICP in an application-relevant chassis organism and the genetic elements that can be used to engineer de novo or enhanced biomineralisation. This study also highlights mutual influences between the genetic drivers and the chemical composition of the surrounding environment in determining the speed, spatial distribution and resulting mineral crystals of MICP. Taken together, these data pave the way for future rational design of synthetic precipitator strains optimised for specific applications. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01704-1.
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Affiliation(s)
- Timothy D Hoffmann
- Department of Biology and Biochemistry, Milner Centre for Evolution, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Kevin Paine
- Department of Architecture and Civil Engineering, BRE Centre for Innovative Construction Materials, University of Bath, Bath, BA2 7AY, United Kingdom
| | - Susanne Gebhard
- Department of Biology and Biochemistry, Milner Centre for Evolution, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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Abstract
Horizontal gene transfer (HGT) is an important factor in bacterial evolution that can act across species boundaries. Yet, we know little about rate and genomic targets of cross-lineage gene transfer and about its effects on the recipient organism's physiology and fitness. Here, we address these questions in a parallel evolution experiment with two Bacillus subtilis lineages of 7% sequence divergence. We observe rapid evolution of hybrid organisms: gene transfer swaps ∼12% of the core genome in just 200 generations, and 60% of core genes are replaced in at least one population. By genomics, transcriptomics, fitness assays, and statistical modeling, we show that transfer generates adaptive evolution and functional alterations in hybrids. Specifically, our experiments reveal a strong, repeatable fitness increase of evolved populations in the stationary growth phase. By genomic analysis of the transfer statistics across replicate populations, we infer that selection on HGT has a broad genetic basis: 40% of the observed transfers are adaptive. At the level of functional gene networks, we find signatures of negative, positive, and epistatic selection, consistent with hybrid incompatibilities and adaptive evolution of network functions. Our results suggest that gene transfer navigates a complex cross-lineage fitness landscape, bridging epistatic barriers along multiple high-fitness paths.
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17
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Nordgaard M, Mortensen RMR, Kirk NK, Gallegos‐Monterrosa R, Kovács ÁT. Deletion of Rap-Phr systems in Bacillus subtilis influences in vitro biofilm formation and plant root colonization. Microbiologyopen 2021; 10:e1212. [PMID: 34180604 PMCID: PMC8236291 DOI: 10.1002/mbo3.1212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 12/19/2022] Open
Abstract
Natural isolates of the soil-dwelling bacterium Bacillus subtilis form robust biofilms under laboratory conditions and colonize plant roots. B. subtilis biofilm gene expression displays phenotypic heterogeneity that is influenced by a family of Rap-Phr regulatory systems. Most Rap-Phr systems in B. subtilis have been studied independently, in different genetic backgrounds and under distinct conditions, hampering true comparison of the Rap-Phr systems' impact on bacterial cell differentiation. Here, we investigated each of the 12 Rap-Phr systems of B.subtilis NCIB 3610 for their effect on biofilm formation. By studying single ∆rap-phr mutants, we show that despite redundancy between the cell-cell communication systems, deletion of each of the 12 Rap-Phr systems influences matrix gene expression. These Rap-Phr systems therefore enable fine-tuning of the timing and level of matrix production in response to specific conditions. Furthermore, some of the ∆rap-phr mutants demonstrated altered biofilm formation in vitro and colonization of Arabidopsis thaliana roots, but not necessarily similarly in both processes, indicating that the pathways regulating matrix gene expression and other factors important for biofilm formation may be differently regulated under these distinct conditions.
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Affiliation(s)
- Mathilde Nordgaard
- Bacterial Interactions and Evolution GroupDTU BioengineeringTechnical University of DenmarkLyngbyDenmark
| | | | - Nikolaj Kaae Kirk
- Bacterial Interactions and Evolution GroupDTU BioengineeringTechnical University of DenmarkLyngbyDenmark
| | | | - Ákos T. Kovács
- Bacterial Interactions and Evolution GroupDTU BioengineeringTechnical University of DenmarkLyngbyDenmark
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18
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Sharipova MR, Mardanova AM, Rudakova NL, Pudova DS. Bistability and Formation of the Biofilm Matrix as Adaptive Mechanisms during the Stationary Phase of Bacillus subtilis. Microbiology (Reading) 2021. [DOI: 10.1134/s002626172006017x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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19
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Genomic and Chemical Diversity of Bacillus subtilis Secondary Metabolites against Plant Pathogenic Fungi. mSystems 2021; 6:6/1/e00770-20. [PMID: 33622852 PMCID: PMC8573961 DOI: 10.1128/msystems.00770-20] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bacillus subtilis produces a wide range of secondary metabolites providing diverse plant growth-promoting and biocontrol abilities. These secondary metabolites include nonribosomal peptides with strong antimicrobial properties, causing either cell lysis, pore formation in fungal membranes, inhibition of certain enzymes, or bacterial protein synthesis. However, the natural products of B. subtilis are mostly studied either in laboratory strains or in individual isolates, and therefore, a comparative overview of secondary metabolites from various environmental B. subtilis strains is missing. In this study, we isolated 23 B. subtilis strains from 11 sampling sites, compared the fungal inhibition profiles of wild types and their nonribosomal peptide mutants, followed the production of targeted lipopeptides, and determined the complete genomes of 13 soil isolates. We discovered that nonribosomal peptide production varied among B. subtilis strains coisolated from the same soil samples. In vitro antagonism assays revealed that biocontrol properties depend on the targeted plant pathogenic fungus and the tested B. subtilis isolate. While plipastatin alone is sufficient to inhibit Fusarium spp., a combination of plipastatin and surfactin is required to hinder growth of Botrytis cinerea Detailed genomic analysis revealed that altered nonribosomal peptide production profiles in specific isolates are due to missing core genes, nonsense mutation, or potentially altered gene regulation. Our study combines microbiological antagonism assays with chemical nonribosomal peptide detection and biosynthetic gene cluster predictions in diverse B. subtilis soil isolates to provide a broader overview of the secondary metabolite chemodiversity of B. subtilis IMPORTANCE Secondary or specialized metabolites with antimicrobial activities define the biocontrol properties of microorganisms. Members of the Bacillus genus produce a plethora of secondary metabolites, of which nonribosomally produced lipopeptides in particular display strong antifungal activity. To facilitate the prediction of the biocontrol potential of new Bacillus subtilis isolates, we have explored the in vitro antifungal inhibitory profiles of recent B. subtilis isolates, combined with analytical natural product chemistry, mutational analysis, and detailed genome analysis of biosynthetic gene clusters. Such a comparative analysis helped to explain why selected B. subtilis isolates lack the production of certain secondary metabolites.
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20
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Eelderink-Chen Z, Bosman J, Sartor F, Dodd AN, Kovács ÁT, Merrow M. A circadian clock in a nonphotosynthetic prokaryote. SCIENCE ADVANCES 2021; 7:eabe2086. [PMID: 33523996 PMCID: PMC7793578 DOI: 10.1126/sciadv.abe2086] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/13/2020] [Indexed: 05/06/2023]
Abstract
Circadian clocks create a 24-hour temporal structure, which allows organisms to occupy a niche formed by time rather than space. They are pervasive throughout nature, yet they remain unexpectedly unexplored and uncharacterized in nonphotosynthetic bacteria. Here, we identify in Bacillus subtilis circadian rhythms sharing the canonical properties of circadian clocks: free-running period, entrainment, and temperature compensation. We show that gene expression in B. subtilis can be synchronized in 24-hour light or temperature cycles and exhibit phase-specific characteristics of entrainment. Upon release to constant dark and temperature conditions, bacterial biofilm populations have temperature-compensated free-running oscillations with a period close to 24 hours. Our work opens the field of circadian clocks in the free-living, nonphotosynthetic prokaryotes, bringing considerable potential for impact upon biomedicine, ecology, and industrial processes.
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Affiliation(s)
- Zheng Eelderink-Chen
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Jasper Bosman
- Department of Bioinformatics, Hanze University of Applied Sciences, Groningen, Zernikeplein 11, 9747 AS Groningen, Netherlands
| | - Francesca Sartor
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Antony N Dodd
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Martha Merrow
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Goethestrasse 31, 80336 Munich, Germany.
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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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22
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Barreto HC, Cordeiro TN, Henriques AO, Gordo I. Rampant loss of social traits during domestication of a Bacillus subtilis natural isolate. Sci Rep 2020; 10:18886. [PMID: 33144634 PMCID: PMC7642357 DOI: 10.1038/s41598-020-76017-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/22/2020] [Indexed: 12/16/2022] Open
Abstract
Most model bacteria have been domesticated in laboratory conditions. Yet, the tempo with which a natural isolate diverges from its ancestral phenotype under domestication to a novel laboratory environment is poorly understood. Such knowledge, however is essential to understanding the rate of evolution, the time scale over which a natural isolate can be propagated without loss of its natural adaptive traits, and the reliability of experimental results across labs. Using experimental evolution, phenotypic assays, and whole-genome sequencing, we show that within a week of propagation in a common laboratory environment, a natural isolate of Bacillus subtilis acquires mutations that cause changes in a multitude of traits. A single adaptive mutational step in the gene coding for the transcriptional regulator DegU impairs a DegU-dependent positive autoregulatory loop and leads to loss of robust biofilm architecture, impaired swarming motility, reduced secretion of exoproteases, and to changes in the dynamics of sporulation across environments. Importantly, domestication also resulted in improved survival when the bacteria face pressure from cells of the innate immune system. These results show that degU is a target for mutations during domestication and underscores the importance of performing careful and extremely short-term propagations of natural isolates to conserve the traits encoded in their original genomes.
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Affiliation(s)
- Hugo C Barreto
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tiago N Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - Isabel Gordo
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.
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23
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Rath H, Sappa PK, Hoffmann T, Gesell Salazar M, Reder A, Steil L, Hecker M, Bremer E, Mäder U, Völker U. Impact of high salinity and the compatible solute glycine betaine on gene expression of Bacillus subtilis. Environ Microbiol 2020; 22:3266-3286. [PMID: 32419322 DOI: 10.1111/1462-2920.15087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/30/2020] [Accepted: 05/13/2020] [Indexed: 12/15/2022]
Abstract
The Gram-positive bacterium Bacillus subtilis is frequently exposed to hyperosmotic conditions. In addition to the induction of genes involved in the accumulation of compatible solutes, high salinity exerts widespread effects on B. subtilis physiology, including changes in cell wall metabolism, induction of an iron limitation response, reduced motility and suppression of sporulation. We performed a combined whole-transcriptome and proteome analysis of B. subtilis 168 cells continuously cultivated at low or high (1.2 M NaCl) salinity. Our study revealed significant changes in the expression of more than one-fourth of the protein-coding genes and of numerous non-coding RNAs. New aspects in understanding the impact of high salinity on B. subtilis include a sustained low-level induction of the SigB-dependent general stress response and strong repression of biofilm formation under high-salinity conditions. The accumulation of compatible solutes such as glycine betaine aids the cells to cope with water stress by maintaining physiologically adequate levels of turgor and also affects multiple cellular processes through interactions with cellular components. Therefore, we additionally analysed the global effects of glycine betaine on the transcriptome and proteome of B. subtilis and revealed that it influences gene expression not only under high-salinity, but also under standard growth conditions.
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Affiliation(s)
- Hermann Rath
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Praveen K Sappa
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Tamara Hoffmann
- Laboratory for Microbiology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Manuela Gesell Salazar
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Alexander Reder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Leif Steil
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Michael Hecker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology e.V. (IMaB), Greifswald, Germany
| | - Erhard Bremer
- Laboratory for Microbiology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology e.V. (IMaB), Greifswald, Germany
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24
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Kai M. Diversity and Distribution of Volatile Secondary Metabolites Throughout Bacillus subtilis Isolates. Front Microbiol 2020; 11:559. [PMID: 32322244 PMCID: PMC7156558 DOI: 10.3389/fmicb.2020.00559] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 03/16/2020] [Indexed: 12/12/2022] Open
Abstract
Bacillus subtilis releases a broad range of volatile secondary metabolites, which are considered as long- and short distance infochemical signals mediating inter- and intra-specific processes. In addition, they often show antimicrobial or antifungal activities. This review attempts to summarize yet known volatile secondary metabolites produced and emitted by Bacillus subtilis isolates focusing on the structural diversity and distribution patterns. Using in vitro volatile-collection systems, 26 strains of B. subtilis isolated from different habitats were found to produce in total 231 volatile secondary metabolites. These volatile secondary metabolites comprised mainly hydrocarbons, ketones, alcohols, aldehydes, ester, acids, aromatics, sulfur- and nitrogen-containing compounds. Reviewed data revealed to a great extent isolate-specific emission patterns. The production and release of several volatile bioactive compounds was retained in isolates of the species B. subtilis, while volatiles without a described function seemed to be isolate-specifically produced. Detailed analysis, however, also indicated that the original data were strongly influenced by insufficient descriptions of the bacterial isolates, heterogeneous and poorly documented culture conditions as well as sampling techniques and inadequate compound identification. In order to get deeper insight into the nature, diversity, and ecological function of volatile secondary metabolites produced by B. subtilis, it will be necessary to follow well-documented workflows and fulfill state-of-the-art standards to unambiguously identify the volatile metabolites. Future research should consider the dynamic of a bacterial culture leading to differences in cell morphology and cell development. Single cell investigations could help to attribute certain volatile metabolites to defined cell forms and developmental stages.
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Affiliation(s)
- Marco Kai
- Institute for Biological Sciences, University of Rostock, Rostock, Germany
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25
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Sedano-Partida MD, Santos KPD, Sala-Carvalho WR, Silva-Luz CL, Furlan CM. Anti-HIV-1 and antibacterial potential of Hyptis radicans (Pohl) Harley & J.F.B. Pastore and Hyptis multibracteata Benth. (Lamiaceae). J Herb Med 2020. [DOI: 10.1016/j.hermed.2019.100328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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26
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Thérien M, Kiesewalter HT, Auria E, Charron-Lamoureux V, Wibowo M, Maróti G, Kovács ÁT, Beauregard PB. Surfactin production is not essential for pellicle and root-associated biofilm development of Bacillus subtilis. Biofilm 2020; 2:100021. [PMID: 33447807 PMCID: PMC7798449 DOI: 10.1016/j.bioflm.2020.100021] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/11/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023] Open
Abstract
Secondary metabolites have an important impact on the biocontrol potential of soil-derived microbes. In addition, various microbe-produced chemicals have been suggested to impact the development and phenotypic differentiation of bacteria, including biofilms. The non-ribosomal synthesized lipopeptide of Bacillus subtilis, surfactin, has been described to impact the plant promoting capacity of the bacterium. Here, we investigated the impact of surfactin production on biofilm formation of B. subtilis using the laboratory model systems; pellicle formation at the air-medium interface and architecturally complex colony development, in addition to plant root-associated biofilms. We found that the production of surfactin by B. subtilis is not essential for pellicle biofilm formation neither in the well-studied strain, NCIB 3610, nor in the newly isolated environmental strains, but lack of surfactin reduces colony expansion. Further, plant root colonization was comparable both in the presence or absence of surfactin synthesis. Our results suggest that surfactin-related biocontrol and plant promotion in B. subtilis strains are independent of biofilm formation.
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Affiliation(s)
- Maude Thérien
- Centre SÈVE, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Canada
| | - Heiko T Kiesewalter
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Emile Auria
- Centre SÈVE, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Canada.,Biology Department, Ecole Normale Supérieure Paris-Saclay, Paris-Saclay University, Cachan, France
| | - Vincent Charron-Lamoureux
- Centre SÈVE, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Canada
| | - Mario Wibowo
- Natural Product Discovery Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Pascale B Beauregard
- Centre SÈVE, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Canada
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27
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Genomic Differences between Listeria monocytogenes EGDe Isolates Reveal Crucial Roles for SigB and Wall Rhamnosylation in Biofilm Formation. J Bacteriol 2020; 202:JB.00692-19. [PMID: 31964697 PMCID: PMC7167478 DOI: 10.1128/jb.00692-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/16/2020] [Indexed: 12/20/2022] Open
Abstract
Biofilms are an important mode of growth in many settings. Here, we looked at small differences in the genomes of the bacterium Listeria monocytogenes isolate EGDe and used them to find out how biofilms form. This important fundamental information may help new treatments to be developed and also highlights the fact that isolates of the same identity often diverge. Listeria monocytogenes is a Gram-positive firmicute that causes foodborne infections, in part due to its ability to use multiple strategies, including biofilm formation, to survive adverse growth conditions. As a potential way to screen for genes required for biofilm formation, we harnessed the ability of bacteria to accumulate mutations in the genome over time, diverging the properties of seemingly identical strains. By sequencing the genomes of four laboratory reference strains of the commonly used L. monocytogenes EGDe, we showed that each isolate contains single nucleotide polymorphisms (SNPs) compared with the reference genome. We discovered that two SNPs, contained in two independent genes within one of the isolates, impacted biofilm formation. Using bacterial genetics and phenotypic assays, we confirmed that rsbU and rmlA influence biofilm formation. RsbU is the upstream regulator of the alternative sigma factor SigB, and mutation of either rsbU or sigB increased biofilm formation. In contrast, deletion of rmlA, which encodes the first enzyme for TDP-l-rhamnose biosynthesis, resulted in a reduction in the amount of biofilm formed. Further analysis of biofilm formation in a strain that still produces TDP-l-rhamnose but which cannot decorate the wall teichoic acid with rhamnose (rmlT mutant) showed that it is the decorated wall teichoic acid that is required for adhesion of the cells to surfaces. Together, these data uncover novel routes by which biofilm formation by L. monocytogenes can be impacted. IMPORTANCE Biofilms are an important mode of growth in many settings. Here, we looked at small differences in the genomes of the bacterium Listeria monocytogenes isolate EGDe and used them to find out how biofilms form. This important fundamental information may help new treatments to be developed and also highlights the fact that isolates of the same identity often diverge.
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28
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Kiesewalter HT, Lozano-Andrade CN, Maróti G, Snyder D, Cooper VS, Jørgensen TS, Weber T, Kovács ÁT. Complete Genome Sequences of 13 Bacillus subtilis Soil Isolates for Studying Secondary Metabolite Diversity. Microbiol Resour Announc 2020; 9:e01406-19. [PMID: 31919181 PMCID: PMC6952667 DOI: 10.1128/mra.01406-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023] Open
Abstract
Bacillus subtilis is a plant-benefiting soil-dwelling Gram-positive bacterium with secondary metabolite production potential. Here, we report the complete genome sequences of 13 B. subtilis strains isolated from different soil samples in Germany and Denmark.
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Affiliation(s)
- Heiko T Kiesewalter
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Carlos N Lozano-Andrade
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Dan Snyder
- Microbial Genome Sequencing Center, Pittsburgh, Pennsylvania, USA
| | - Vaughn S Cooper
- Microbial Genome Sequencing Center, Pittsburgh, Pennsylvania, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Tue Sparholt Jørgensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Tilmann Weber
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
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29
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Falcón García C, Kretschmer M, Lozano-Andrade CN, Schönleitner M, Dragoŝ A, Kovács ÁT, Lieleg O. Metal ions weaken the hydrophobicity and antibiotic resistance of Bacillus subtilis NCIB 3610 biofilms. NPJ Biofilms Microbiomes 2020; 6:1. [PMID: 31908831 PMCID: PMC6941983 DOI: 10.1038/s41522-019-0111-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/03/2019] [Indexed: 02/06/2023] Open
Abstract
Surface superhydrophobicity makes bacterial biofilms very difficult to fight, and it is a combination of their matrix composition and complex surface roughness which synergistically protects these biomaterials from wetting. Although trying to eradicate biofilms with aqueous (antibiotic) solutions is common practice, this can be a futile approach if the biofilms have superhydrophobic properties. To date, there are not many options available to reduce the liquid repellency of biofilms or to prevent this material property from developing. Here, we present a solution to this challenge. We demonstrate how the addition of metal ions such as copper and zinc during or after biofilm formation can render the surface of otherwise superhydrophobic B. subtilis NCIB 3610 biofilms completely wettable. As a result of this procedure, these smoother, hydrophilic biofilms are more susceptible to aqueous antibiotics solutions. Our strategy proposes a scalable and widely applicable step in a multi-faceted approach to eradicate biofilms.
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Affiliation(s)
- Carolina Falcón García
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Martin Kretschmer
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Carlos N. Lozano-Andrade
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800 Kongens Lyngby, Denmark
| | - Markus Schönleitner
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
| | - Anna Dragoŝ
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800 Kongens Lyngby, Denmark
| | - Ákos T. Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800 Kongens Lyngby, Denmark
| | - Oliver Lieleg
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstraße 11, 85748 Garching, Germany
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30
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Kjeldgaard B, Listian SA, Ramaswamhi V, Richter A, Kiesewalter HT, Kovács ÁT. Fungal hyphae colonization by Bacillus subtilis relies on biofilm matrix components. Biofilm 2019; 1:100007. [PMID: 33447794 PMCID: PMC7798453 DOI: 10.1016/j.bioflm.2019.100007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/15/2019] [Accepted: 10/19/2019] [Indexed: 02/07/2023] Open
Abstract
Bacteria interact with their environment including microbes and higher eukaryotes. The ability of bacteria and fungi to affect each other are defined by various chemical, physical and biological factors. During physical association, bacterial cells can directly attach and settle on the hyphae of various fungal species. Such colonization of mycelia was proposed to be dependent on biofilm formation by the bacteria, but the essentiality of the biofilm matrix was not represented before. Here, we demonstrate that secreted biofilm matrix components of the soil-dwelling bacterium, Bacillus subtilis are essential for the establishment of a dense bacterial population on the hyphae of the filamentous black mold fungus, Aspergillus niger and the basidiomycete mushroom, Agaricus bisporus. We further illustrate that these matrix components can be shared among various mutants highlighting the community shaping impact of biofilm formers on bacteria-fungi interactions.
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Affiliation(s)
- Bodil Kjeldgaard
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Stevanus A Listian
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Valliyammai Ramaswamhi
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Anne Richter
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Heiko T Kiesewalter
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
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31
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Devi S, Kiesewalter HT, Kovács R, Frisvad JC, Weber T, Larsen TO, Kovács ÁT, Ding L. Depiction of secondary metabolites and antifungal activity of Bacillus velezensis DTU001. Synth Syst Biotechnol 2019; 4:142-149. [PMID: 31508511 PMCID: PMC6719288 DOI: 10.1016/j.synbio.2019.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 12/25/2022] Open
Abstract
For a safe and sustainable environment, effective microbes as biocontrol agents are in high demand. We have isolated a new Bacillus velezensis strain DTU001, investigated its antifungal spectrum, sequenced its genome, and uncovered the production of lipopeptides in HPLC-HRMS analysis. To test the antifungal efficacy, extracts of B. velezensis DTU001 was tested against a range of twenty human or plant pathogenic fungi. We demonstrate that inhibitory potential of B. velezensis DTU001 against selected fungi is superior in comparison to single lipopeptide, either iturin or fengycin. The isolate showed analogous biofilm formation to other closely related Bacilli. To further support the biocontrol properties of the isolate, coculture with Candida albicans demonstrated that B. velezensis DTU001 exhibited excellent antiproliferation effect against C. albicans. In summary, the described isolate is a potential antifungal agent with a broad antifungal spectrum that might assist our aims to avoid hazardous pathogenic fungi and provide alternative to toxicity caused by chemicals.
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Affiliation(s)
- Sagarika Devi
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Heiko T Kiesewalter
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032, Debrecen, Hungary
| | - Jens Christian Frisvad
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Tilmann Weber
- Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Thomas Ostenfeld Larsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Ákos T Kovács
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Ling Ding
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
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32
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Sartor F, Eelderink-Chen Z, Aronson B, Bosman J, Hibbert LE, Dodd AN, Kovács ÁT, Merrow M. Are There Circadian Clocks in Non-Photosynthetic Bacteria? BIOLOGY 2019; 8:E41. [PMID: 31121908 PMCID: PMC6627678 DOI: 10.3390/biology8020041] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/15/2019] [Accepted: 05/15/2019] [Indexed: 01/01/2023]
Abstract
Circadian clocks in plants, animals, fungi, and in photosynthetic bacteria have been well-described. Observations of circadian rhythms in non-photosynthetic Eubacteria have been sporadic, and the molecular basis for these potential rhythms remains unclear. Here, we present the published experimental and bioinformatical evidence for circadian rhythms in these non-photosynthetic Eubacteria. From this, we suggest that the timekeeping functions of these organisms will be best observed and studied in their appropriate complex environments. Given the rich temporal changes that exist in these environments, it is proposed that microorganisms both adapt to and contribute to these daily dynamics through the process of temporal mutualism. Understanding the timekeeping and temporal interactions within these systems will enable a deeper understanding of circadian clocks and temporal programs and provide valuable insights for medicine and agriculture.
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Affiliation(s)
- Francesca Sartor
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336 Munich, Germany.
| | - Zheng Eelderink-Chen
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336 Munich, Germany.
| | - Ben Aronson
- Department of Biology, University of Redlands, Redlands, CA 92373, USA.
| | - Jasper Bosman
- Bioinformatics, Hanzehogeschool Groningen, 9747 AS Groningen, The Netherlands.
| | - Lauren E Hibbert
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK.
| | - Antony N Dodd
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK.
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Martha Merrow
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336 Munich, Germany.
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Kovács ÁT, Dragoš A. Evolved Biofilm: Review on the Experimental Evolution Studies of Bacillus subtilis Pellicles. J Mol Biol 2019; 431:4749-4759. [PMID: 30769118 DOI: 10.1016/j.jmb.2019.02.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 01/21/2019] [Accepted: 02/04/2019] [Indexed: 12/25/2022]
Abstract
For several decades, laboratory evolution has served as a powerful method to manipulate microorganisms and to explore long-term dynamics in microbial populations. Next to canonical Escherichia coli planktonic cultures, experimental evolution has expanded into alternative cultivation methods and species, opening the doors to new research questions. Bacillus subtilis, the spore-forming and root-colonizing bacterium, can easily develop in the laboratory as a liquid-air interface colonizing pellicle biofilm. Here, we summarize recent findings derived from this tractable experimental model. Clonal pellicle biofilms of B. subtilis can rapidly undergo morphological and genetic diversification creating new ecological interactions, for example, exploitation by biofilm non-producers. Moreover, long-term exposure to such matrix non-producers can modulate cooperation in biofilms, leading to different phenotypic heterogeneity pattern of matrix production with larger subpopulation of "ON" cells. Alternatively, complementary variants of biofilm non-producers, each lacking a distinct matrix component, can engage in a genetic division of labor, resulting in superior biofilm productivity compared to the "generalist" wild type. Nevertheless, inter-genetic cooperation appears to be evanescent and rapidly vanquished by individual biofilm formation strategies altering the amount or the properties of the remaining matrix component. Finally, fast-evolving mobile genetic elements can unpredictably shift intra-species interactions in B. subtilis biofilms. Understanding evolution in clonal biofilm populations will facilitate future studies in complex multispecies biofilms that are more representative of nature.
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Affiliation(s)
- Ákos T Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
| | - Anna Dragoš
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
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Klotz M, Kretschmer M, Goetz A, Ezendam S, Lieleg O, Opitz M. Importance of the biofilm matrix for the erosion stability of Bacillus subtilis NCIB 3610 biofilms. RSC Adv 2019; 9:11521-11529. [PMID: 35520264 PMCID: PMC9063333 DOI: 10.1039/c9ra01955c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 04/02/2019] [Indexed: 12/12/2022] Open
Abstract
Erosion of bacterial biofilms is dependent on the composition of the biofilm matrix and the surrounding chemical environment.
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Affiliation(s)
- M. Klotz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - M. Kretschmer
- Munich School of BioEngineering and Department of Mechanical Engineering
- Technische Universität München
- Garching
- Germany
| | - A. Goetz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - S. Ezendam
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - O. Lieleg
- Munich School of BioEngineering and Department of Mechanical Engineering
- Technische Universität München
- Garching
- Germany
| | - M. Opitz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
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Wu Q, Zhi Y, Xu Y. Systematically engineering the biosynthesis of a green biosurfactant surfactin by Bacillus subtilis 168. Metab Eng 2018; 52:87-97. [PMID: 30453038 DOI: 10.1016/j.ymben.2018.11.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 11/24/2022]
Abstract
The biosynthesis of surfactin has attracted broad interest; however, there is a bottleneck in its low yield in wild strains and the ability to engineer Bacillus producers. Because the key metabolic mechanisms in the surfactin synthesis pathway remain unclear, genetic engineering approaches are all ending up with a single or a few gene modifications. The aim of this study is to develop a systematic engineering approach to improve the biosynthesis of surfactin. First, we restored surfactin biosynthetic activity by integrating a complete sfp gene into the nonproducing Bacillus subtilis 168 strain and obtained a surfactin titer of 0.4 g/l. Second, we reduced competition by deleting biofilm formation-related genes and nonribosomal peptide synthetases/polyketide synthase pathways (3.8% of the total genome), which increased the surfactin titer by 3.3-fold. Third, we improved cellular tolerance to surfactin by overexpressing potential self-resistance-associated proteins, which further increased the surfactin titer by 8.5-fold. Fourth, we increased the supply of precursor branched-chain fatty acids by engineering the branched-chain fatty acid biosynthesis pathway, resulting in an increase of the surfactin titer to 8.5 g/l (a 20.3-fold increase). Finally, due to the preference of the glycolytic pathway for cell growth, we diverted precursor acetyl-CoA away from cell growth to surfactin biosynthesis by enhancing the transcription of srfA. The final surfactin titer increased to 12.8 g/l, with a yield of 65.0 mmol/mol sucrose (42% of the theoretical yield) in the metabolically engineered strain. To the best of our knowledge, this is the highest titer and yield that has been reported. This study may pave the way for the commercial production of green surfactin. More broadly, our work presents another successful example of the modularization of metabolic pathways for improving titer and yield in biotechnological production.
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Affiliation(s)
- Qun Wu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Suqian Industrial Technology Research Institute of Jiangnan University, Suqian 223800, China
| | - Yan Zhi
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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Dragoš A, Lakshmanan N, Martin M, Horváth B, Maróti G, Falcón García C, Lieleg O, Kovács ÁT. Evolution of exploitative interactions during diversification in Bacillus subtilis biofilms. FEMS Microbiol Ecol 2018; 93:4604779. [PMID: 29126191 DOI: 10.1093/femsec/fix155] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/07/2017] [Indexed: 12/19/2022] Open
Abstract
Microbial biofilms are tightly packed, heterogeneous structures that serve as arenas for social interactions. Studies on Gram negative models reveal that during evolution in structured environments like biofilms, isogenic populations commonly diversify into phenotypically and genetically distinct variants. These variants can settle in alternative biofilm niches and develop new types of interactions that greatly influence population productivity. Here, we explore the evolutionary diversification of pellicle biofilms of the Gram positive, spore-forming bacterium Bacillus subtilis. We discovered that-similarly to other species-B. subtilis diversifies into distinct colony variants. These variants dramatically differ in biofilm formation abilities and expression of biofilm-related genes. In addition, using a quantitative approach, we reveal striking differences in surface complexity and hydrophobicity of the evolved colony types. Interestingly, one of the morphotypes completely lost the ability of independent biofilm formation and evolved to hitchhike with other morphotypes with improved biofilm forming abilities. Genome comparison suggests that major phenotypic transformations between the morphotypes can be triggered by subtle genetic differences. Our work demonstrates how positive complementarity effects and exploitative interactions intertwine during evolutionary diversification in biofilms.
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Affiliation(s)
- Anna Dragoš
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Anker Engelunds Vej Building 301, Kgs Lyngby 2800, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 23, Jena 07743, Germany
| | - Nivedha Lakshmanan
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 23, Jena 07743, Germany
| | - Marivic Martin
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Anker Engelunds Vej Building 301, Kgs Lyngby 2800, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 23, Jena 07743, Germany
| | - Balázs Horváth
- Seqomics Biotechnology Ltd, Vállalkozók útja 7, Mórahalom 6782, Hungary
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged 6726, Hungary
| | - Carolina Falcón García
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstr. 11, Garching 85748, Germany
| | - Oliver Lieleg
- Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, Boltzmannstr. 11, Garching 85748, Germany
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Anker Engelunds Vej Building 301, Kgs Lyngby 2800, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 23, Jena 07743, Germany
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Richter A, Hölscher T, Pausch P, Sehrt T, Brockhaus F, Bange G, Kovács ÁT. Hampered motility promotes the evolution of wrinkly phenotype in Bacillus subtilis. BMC Evol Biol 2018; 18:155. [PMID: 30326845 PMCID: PMC6192195 DOI: 10.1186/s12862-018-1266-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/26/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Selection for a certain trait in microbes depends on the genetic background of the strain and the selection pressure of the environmental conditions acting on the cells. In contrast to the sessile state in the biofilm, various bacterial cells employ flagellum-dependent motility under planktonic conditions suggesting that the two phenotypes are mutually exclusive. However, flagellum dependent motility facilitates the prompt establishment of floating biofilms on the air-medium interface, called pellicles. Previously, pellicles of B. subtilis were shown to be preferably established by motile cells, causing a reduced fitness of non-motile derivatives in the presence of the wild type strain. RESULTS Here, we show that lack of active flagella promotes the evolution of matrix overproducers that can be distinguished by the characteristic wrinkled colony morphotype. The wrinkly phenotype is associated with amino acid substitutions in the master repressor of biofilm-related genes, SinR. By analyzing one of the mutations, we show that it alters the tetramerization and DNA binding properties of SinR, allowing an increased expression of the operon responsible for exopolysaccharide production. Finally, we demonstrate that the wrinkly phenotype is advantageous when cells lack flagella, but not in the wild type background. CONCLUSIONS Our experiments suggest that loss of function phenotypes could expose rapid evolutionary adaptation in bacterial biofilms that is otherwise not evident in the wild type strains.
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Affiliation(s)
- Anne Richter
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads Building 221, 2800, Kongens Lyngby, Denmark.,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Theresa Hölscher
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Patrick Pausch
- LOEWE Center for Synthetic Microbiology, Department of Chemistry, Philipps University Marburg, 35043, Marburg, Germany
| | - Tim Sehrt
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Franziska Brockhaus
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Gert Bange
- LOEWE Center for Synthetic Microbiology, Department of Chemistry, Philipps University Marburg, 35043, Marburg, Germany
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads Building 221, 2800, Kongens Lyngby, Denmark. .,Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany.
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Hölscher T, Schiklang T, Dragoš A, Dietel AK, Kost C, Kovács ÁT. Impaired competence in flagellar mutants of Bacillus subtilis is connected to the regulatory network governed by DegU. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:23-32. [PMID: 29124898 DOI: 10.1111/1758-2229.12601] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/01/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
The competent state is a developmentally distinct phase, in which bacteria are able to take up and integrate exogenous DNA into their genome. Bacillus subtilis is one of the naturally competent bacterial species and the domesticated laboratory strain 168 is easily transformable. In this study, we report a reduced transformation frequency of B. subtilis mutants lacking functional and structural flagellar components. This includes hag, the gene encoding the flagellin protein forming the filament of the flagellum. We confirm that the observed decrease of the transformation frequency is due to reduced expression of competence genes, particularly of the main competence regulator gene comK. The impaired competence is due to an increase in the phosphorylated form of the response regulator DegU, which is involved in regulation of both flagellar motility and competence. Altogether, our study identified a close link between motility and natural competence in B. subtilis suggesting that hindrance in motility has great impact on differentiation of this bacterium not restricted only to the transition towards sessile growth stage.
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Affiliation(s)
- Theresa Hölscher
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Tina Schiklang
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Anna Dragoš
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Anne-Kathrin Dietel
- Experimental Ecology and Evolution Group, Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Ecology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Christian Kost
- Experimental Ecology and Evolution Group, Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- Department of Ecology, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | - Ákos T Kovács
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs Lyngby, Denmark
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Lysinibacillus fusiformis M5 Induces Increased Complexity in Bacillus subtilis 168 Colony Biofilms via Hypoxanthine. J Bacteriol 2017; 199:JB.00204-17. [PMID: 28583948 DOI: 10.1128/jb.00204-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/30/2017] [Indexed: 12/18/2022] Open
Abstract
In recent years, biofilms have become a central subject of research in the fields of microbiology, medicine, agriculture, and systems biology, among others. The sociomicrobiology of multispecies biofilms, however, is still poorly understood. Here, we report a screening system that allowed us to identify soil bacteria which induce architectural changes in biofilm colonies when cocultured with Bacillus subtilis We identified the soil bacterium Lysinibacillus fusiformis M5 as an inducer of wrinkle formation in B. subtilis colonies mediated by a diffusible signaling molecule. This compound was isolated by bioassay-guided chromatographic fractionation. The elicitor was identified to be the purine hypoxanthine using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. We show that the induction of wrinkle formation by hypoxanthine is not dependent on signal recognition by the histidine kinases KinA, KinB, KinC, and KinD, which are generally involved in phosphorylation of the master regulator Spo0A. Likewise, we show that hypoxanthine signaling does not induce the expression of biofilm matrix-related operons epsABCDEFGHIJKLMNO and tasA-sipW-tapA Finally, we demonstrate that the purine permease PbuO, but not PbuG, is necessary for hypoxanthine to induce an increase in wrinkle formation of B. subtilis biofilm colonies. Our results suggest that hypoxanthine-stimulated wrinkle development is not due to a direct induction of biofilm-related gene expression but rather is caused by the excess of hypoxanthine within B. subtilis cells, which may lead to cell stress and death.IMPORTANCE Biofilms are a bacterial lifestyle with high relevance regarding diverse human activities. Biofilms can be beneficial, for instance, in crop protection. In nature, biofilms are commonly found as multispecies communities displaying complex social behaviors and characteristics. The study of interspecies interactions will thus lead to a better understanding and use of biofilms as they occur outside laboratory conditions. Here, we present a screening method suitable for the identification of multispecies interactions and showcase L. fusiformis as a soil bacterium that is able to live alongside B. subtilis and modify the architecture of its biofilms.
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40
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Modulation of calcium carbonate precipitation by exopolysaccharide in Bacillus sp. JH7. Appl Microbiol Biotechnol 2017. [DOI: 10.1007/s00253-017-8372-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Presence of Calcium Lowers the Expansion of Bacillus subtilis Colony Biofilms. Microorganisms 2017; 5:microorganisms5010007. [PMID: 28212310 PMCID: PMC5374384 DOI: 10.3390/microorganisms5010007] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/02/2017] [Accepted: 02/08/2017] [Indexed: 11/17/2022] Open
Abstract
Robust colony formation by Bacillus subtilis is recognized as one of the sessile, multicellular lifestyles of this bacterium. Numerous pathways and genes are responsible for the architecturally complex colony structure development. Cells in the biofilm colony secrete extracellular polysaccharides (EPS) and protein components (TasA and the hydrophobin BslA) that hold them together and provide a protective hydrophobic shield. Cells also secrete surfactin with antimicrobial as well as surface tension reducing properties that aid cells to colonize the solid surface. Depending on the environmental conditions, these secreted components of the colony biofilm can also promote the flagellum-independent surface spreading of B. subtilis, called sliding. In this study, we emphasize the influence of Ca2+ in the medium on colony expansion of B. subtilis. Interestingly, the availability of Ca2+ has no major impact on the induction of complex colony morphology. However, in the absence of this divalent ion, peripheral cells of the colony expand radially at later stages of development, causing colony size to increase. We demonstrate that the secreted extracellular compounds, EPS, BslA, and surfactin facilitate colony expansion after biofilm maturation. We propose that Ca2+ hinders biofilm colony expansion by modifying the amphiphilic properties of surfactin.
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42
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An improved protocol for harvesting Bacillus subtilis colony biofilms. J Microbiol Methods 2017; 134:7-13. [PMID: 28069469 DOI: 10.1016/j.mimet.2017.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/03/2017] [Accepted: 01/03/2017] [Indexed: 12/11/2022]
Abstract
Bacterial biofilms cause severe problems in medicine and industry due to the high resistance to disinfectants and environmental stress of organisms within biofilms. Addressing challenges caused by biofilms requires full understanding of the underlying mechanisms for bacterial resistance and survival in biofilms. However, such work is hampered by a relative lack of systems for biofilm cultivation that are practical and reproducible. To address this problem, we developed a readily applicable method to culture Bacillus subtilis biofilms on a membrane filter. The method results in biofilms with highly reproducible characteristics, and which can be readily analyzed by a variety of methods with little further manipulation. This biofilm preparation method simplifies routine generation of B. subtilis biofilms for molecular and cellular analysis, and could be applicable to other microbial systems.
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Kesel S, von Bronk B, Falcón García C, Götz A, Lieleg O, Opitz M. Matrix composition determines the dimensions of Bacillus subtilis NCIB 3610 biofilm colonies grown on LB agar. RSC Adv 2017. [DOI: 10.1039/c7ra05559e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Exopolymeric substances secreted by biofilm formingBacillus subtilisNCIB 3610 bacteria influence the growth and final dimensions of these biofilms.
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Affiliation(s)
- Sara Kesel
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - Benedikt von Bronk
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - Carolina Falcón García
- Institute of Medical Engineering IMETUM
- Department of Mechanical Engineering
- Technische Universität München
- Garching
- Germany
| | - Alexandra Götz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
| | - Oliver Lieleg
- Institute of Medical Engineering IMETUM
- Department of Mechanical Engineering
- Technische Universität München
- Garching
- Germany
| | - Madeleine Opitz
- Center for NanoScience
- Faculty of Physics
- Ludwig-Maximilians-Universität München
- Munich
- Germany
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