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Povolotsky TL, Levy Barazany H, Shacham Y, Kolodkin-Gal I. Bacterial epigenetics and its implication for agriculture, probiotics development, and biotechnology design. Biotechnol Adv 2024; 75:108414. [PMID: 39019123 DOI: 10.1016/j.biotechadv.2024.108414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 07/12/2024] [Accepted: 07/13/2024] [Indexed: 07/19/2024]
Abstract
In their natural habitats, organisms encounter numerous external stimuli and must be able to sense and adapt to those stimuli to survive. Unlike mutations, epigenetic changes do not alter the underlying DNA sequence. Instead, they create modifications that promote or silence gene expression. Bacillus subtilis has long been a model organism in studying genetics and development. It is beneficial for numerous biotechnological applications where it is included as a probiotic, in fermentation, or in bio-concrete design. This bacterium has also emerged recently as a model organism for studying bacterial epigenetic adaptation. In this review, we examine the evolving knowledge of epigenetic regulation (restriction-modification systems (RM), orphan methyltransferases, and chromosome condensation) in B. subtilis and related bacteria, and utilize it as a case study to test their potential roles and future applications in genetic engineering and microbial biotechnology. Finally, we suggest how the implementation of these fundamental findings promotes the design of synthetic epigenetic memory circuits and their future applications in agriculture, medicine, and biotechnology.
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Affiliation(s)
- Tatyana L Povolotsky
- Institute for Chemistry and Biochemistry, Physical and Theoretical Chemistry, Freie Universität Berlin, Altensteinstraße 23A, 14195 Berlin, Germany
| | - Hilit Levy Barazany
- Scojen Institute for Synthetic Biology, Reichman University, Hauniversita 8, Herzeliya, Israel
| | - Yosi Shacham
- Scojen Institute for Synthetic Biology, Reichman University, Hauniversita 8, Herzeliya, Israel
| | - Ilana Kolodkin-Gal
- Scojen Institute for Synthetic Biology, Reichman University, Hauniversita 8, Herzeliya, Israel.
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2
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La Corte SG, Stevens CA, Cárcamo-Oyarce G, Ribbeck K, Wingreen NS, Datta SS. Morphogenesis of bacterial colonies in polymeric environments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590088. [PMID: 38712130 PMCID: PMC11071276 DOI: 10.1101/2024.04.18.590088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Many bacteria live in polymeric fluids, such as mucus, environmental polysaccharides, and extracellular polymers in biofilms. However, lab studies typically focus on cells in polymer-free fluids. Here, we show that interactions with polymers shape a fundamental feature of bacterial life-how they proliferate in space in multicellular colonies. Using experiments, we find that when polymer is sufficiently concentrated, cells generically and reversibly form large serpentine "cables" as they proliferate. By combining experiments with biophysical theory and simulations, we demonstrate that this distinctive form of colony morphogenesis arises from an interplay between polymer-induced entropic attraction between neighboring cells and their hindered ability to diffusely separate from each other in a viscous polymer solution. Our work thus reveals a pivotal role of polymers in sculpting proliferating bacterial colonies, with implications for how they interact with hosts and with the natural environment, and uncovers quantitative principles governing colony morphogenesis in such complex environments.
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3
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Sarma A, Dhandapani G, Phukan H, Bhunia PK, De AK, Bhattacharya D, Jebasingh T, Madanan MG. Leptospiral cell wall hydrolase (LIC_10271) binding peptidoglycan, lipopolysaccharide, and laminin and the protein show LysM and M23 domains are co-existing in pathogenic species. Res Microbiol 2023; 174:104107. [PMID: 37517629 DOI: 10.1016/j.resmic.2023.104107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/07/2023] [Accepted: 07/21/2023] [Indexed: 08/01/2023]
Abstract
Leptospirosis, a global reemerging zoonosis caused by the spirochete Leptospira, has severe human and veterinary implications. Cell wall hydrolase (LIC_10271) with LytM (peptidase M23) and LysM domains are found to be associated with various pathogenic bacteria. These domains regulate effects on extracellular matrix and biofilm components, which promote cell wall remodeling and pathogen dissemination in the host. In this study, we present the cloning, expression, purification, and characterization of LIC_10271. To determine the localization of LIC_10271 within the inner membrane of Leptospira, Triton X-114 subcellular fractionation and immunoblot studies were performed. Furthermore, r-LIC_10271 binds with peptidoglycan, lipopolysaccharide, and laminin in a dose-dependent manner. Analysis of the signal peptide, M23, and LysM domains revealed conservation primarily within the P1 group of Leptospira, which encompasses the most pathogenic species. Moreover, the presence of native-LIC_10271 in the inner membrane and the distribution of M23 and LysM domains across pathogenic strains indicates their potential involvement in the interaction between the host and Leptospira.
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Affiliation(s)
- Abhijit Sarma
- Department of Biochemistry, ICMR - Regional Medical Research Centre, Port Blair 744103, Andaman and Nicobar Islands, India
| | - Gunasekaran Dhandapani
- Department of Biochemistry, ICMR - Regional Medical Research Centre, Port Blair 744103, Andaman and Nicobar Islands, India
| | - Homen Phukan
- Department of Biochemistry, ICMR - Regional Medical Research Centre, Port Blair 744103, Andaman and Nicobar Islands, India
| | - Prasun Kumar Bhunia
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamraj University, Madurai, Tamil Nadu 625021, India
| | - Arun Kumar De
- Division of Animal Science, ICAR- Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands 744101, India
| | - Debasis Bhattacharya
- Division of Animal Science, ICAR- Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands 744101, India
| | - T Jebasingh
- Department of Plant Sciences, School of Biological Sciences, Madurai Kamraj University, Madurai, Tamil Nadu 625021, India
| | - Madathiparambil G Madanan
- Department of Biochemistry, ICMR - Regional Medical Research Centre, Port Blair 744103, Andaman and Nicobar Islands, India.
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4
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Xie CY, Li WJ, Feng H. Tuning transcription factor DegU for developing extracellular protease overproducer in Bacillus pumilus. Microb Cell Fact 2023; 22:163. [PMID: 37635205 PMCID: PMC10464342 DOI: 10.1186/s12934-023-02177-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023] Open
Abstract
BACKGROUND Global transcription machinery engineering (gTME) is an effective approach employed in strain engineering to rewire gene expression and reshape cellular metabolic fluxes at the transcriptional level. RESULTS In this study, we utilized gTME to engineer the positive transcription factor, DegU, in the regulation network of major alkaline protease, AprE, in Bacillus pumilus. To validate its functionality when incorporated into the chromosome, we performed several experiments. First, three negative transcription factors, SinR, Hpr, and AbrB, were deleted to promote AprE synthesis. Second, several hyper-active DegU mutants, designated as DegU(hy), were selected using the fluorescence colorimetric method with the host of the Bacillus subtilis ΔdegSU mutant. Third, we integrated a screened degU(L113F) sequence into the chromosome of the Δhpr mutant of B. pumilus SCU11 to replace the original degU gene using a CRISPR/Cas9 system. Finally, based on transcriptomic and molecular dynamic analysis, we interpreted the possible mechanism of high-yielding and found that the strain produced alkaline proteases 2.7 times higher than that of the control strain (B. pumilus SCU11) in LB medium. CONCLUSION Our findings serve as a proof-of-concept that tuning the global regulator is feasible and crucial for improving the production performance of B. pumilus. Additionally, our study established a paradigm for gene function research in strains that are difficult to handle.
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Affiliation(s)
- Chao-Ying Xie
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Wen-Jin Li
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China
| | - Hong Feng
- Key Laboratory for Bio-resources and Eco-Environment of the Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu, 610064, People's Republic of China.
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Stülke J, Grüppen A, Bramkamp M, Pelzer S. Bacillus subtilis, a Swiss Army Knife in Science and Biotechnology. J Bacteriol 2023; 205:e0010223. [PMID: 37140386 PMCID: PMC10210981 DOI: 10.1128/jb.00102-23] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Next to Escherichia coli, Bacillus subtilis is the most studied and best understood organism that also serves as a model for many important pathogens. Due to its ability to form heat-resistant spores that can germinate even after very long periods of time, B. subtilis has attracted much scientific interest. Another feature of B. subtilis is its genetic competence, a developmental state in which B. subtilis actively takes up exogenous DNA. This makes B. subtilis amenable to genetic manipulation and investigation. The bacterium was one of the first with a fully sequenced genome, and it has been subject to a wide variety of genome- and proteome-wide studies that give important insights into many aspects of the biology of B. subtilis. Due to its ability to secrete large amounts of proteins and to produce a wide range of commercially interesting compounds, B. subtilis has become a major workhorse in biotechnology. Here, we review the development of important aspects of the research on B. subtilis with a specific focus on its cell biology and biotechnological and practical applications from vitamin production to concrete healing. The intriguing complexity of the developmental programs of B. subtilis, paired with the availability of sophisticated tools for genetic manipulation, positions it at the leading edge for discovering new biological concepts and deepening our understanding of the organization of bacterial cells.
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Affiliation(s)
- Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Marc Bramkamp
- Institute for General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
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Lazar V, Oprea E, Ditu LM. Resistance, Tolerance, Virulence and Bacterial Pathogen Fitness-Current State and Envisioned Solutions for the Near Future. Pathogens 2023; 12:pathogens12050746. [PMID: 37242416 DOI: 10.3390/pathogens12050746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
The current antibiotic crisis and the global phenomena of bacterial resistance, inherited and non-inherited, and tolerance-associated with biofilm formation-are prompting dire predictions of a post-antibiotic era in the near future. These predictions refer to increases in morbidity and mortality rates as a consequence of infections with multidrug-resistant or pandrug-resistant microbial strains. In this context, we aimed to highlight the current status of the antibiotic resistance phenomenon and the significance of bacterial virulence properties/fitness for human health and to review the main strategies alternative or complementary to antibiotic therapy, some of them being already clinically applied or in clinical trials, others only foreseen and in the research phase.
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Affiliation(s)
- Veronica Lazar
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 1-3 Portocalelor Street, 060101 Bucharest, Romania
| | - Eliza Oprea
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 1-3 Portocalelor Street, 060101 Bucharest, Romania
| | - Lia-Mara Ditu
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 1-3 Portocalelor Street, 060101 Bucharest, Romania
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7
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Hengge R, Pruteanu M, Stülke J, Tschowri N, Turgay K. Recent advances and perspectives in nucleotide second messenger signaling in bacteria. MICROLIFE 2023; 4:uqad015. [PMID: 37223732 PMCID: PMC10118264 DOI: 10.1093/femsml/uqad015] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/28/2023] [Accepted: 04/13/2023] [Indexed: 05/25/2023]
Abstract
Nucleotide second messengers act as intracellular 'secondary' signals that represent environmental or cellular cues, i.e. the 'primary' signals. As such, they are linking sensory input with regulatory output in all living cells. The amazing physiological versatility, the mechanistic diversity of second messenger synthesis, degradation, and action as well as the high level of integration of second messenger pathways and networks in prokaryotes has only recently become apparent. In these networks, specific second messengers play conserved general roles. Thus, (p)ppGpp coordinates growth and survival in response to nutrient availability and various stresses, while c-di-GMP is the nucleotide signaling molecule to orchestrate bacterial adhesion and multicellularity. c-di-AMP links osmotic balance and metabolism and that it does so even in Archaea may suggest a very early evolutionary origin of second messenger signaling. Many of the enzymes that make or break second messengers show complex sensory domain architectures, which allow multisignal integration. The multiplicity of c-di-GMP-related enzymes in many species has led to the discovery that bacterial cells are even able to use the same freely diffusible second messenger in local signaling pathways that can act in parallel without cross-talking. On the other hand, signaling pathways operating with different nucleotides can intersect in elaborate signaling networks. Apart from the small number of common signaling nucleotides that bacteria use for controlling their cellular "business," diverse nucleotides were recently found to play very specific roles in phage defense. Furthermore, these systems represent the phylogenetic ancestors of cyclic nucleotide-activated immune signaling in eukaryotes.
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Affiliation(s)
- Regine Hengge
- Corresponding author. Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Philippstr. 13 – Haus 22, 10115 Berlin, Germany. Tel: +49-30-2093-49686; Fax: +49-30-2093-49682; E-mail:
| | | | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Natalia Tschowri
- Institute of Microbiology, Leibniz-Universität Hannover, 30419 Hannover, Germany
| | - Kürşad Turgay
- Institute of Microbiology, Leibniz-Universität Hannover, 30419 Hannover, Germany
- Max Planck Unit for the Science of Pathogens, 10115 Berlin, Germany
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8
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Biofilms and Benign Colonic Diseases. Int J Mol Sci 2022; 23:ijms232214259. [PMID: 36430737 PMCID: PMC9698058 DOI: 10.3390/ijms232214259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022] Open
Abstract
The colon has a very large surface area that is covered by a dense mucus layer. The biomass in the colon includes 500-1000 bacterial species at concentrations of ~1012 colony-forming units per gram of feces. The intestinal epithelial cells and the commensal bacteria in the colon have a symbiotic relationship that results in nutritional support for the epithelial cells by the bacteria and maintenance of the optimal commensal bacterial population by colonic host defenses. Bacteria can form biofilms in the colon, but the exact frequency is uncertain because routine methods to undertake colonoscopy (i.e., bowel preparation) may dislodge these biofilms. Bacteria in biofilms represent a complex community that includes living and dead bacteria and an extracellular matrix composed of polysaccharides, proteins, DNA, and exogenous debris in the colon. The formation of biofilms occurs in benign colonic diseases, such as inflammatory bowel disease and irritable bowel syndrome. The development of a biofilm might serve as a marker for ongoing colonic inflammation. Alternatively, the development of biofilms could contribute to the pathogenesis of these disorders by providing sanctuaries for pathogenic bacteria and reducing the commensal bacterial population. Therapeutic approaches to patients with benign colonic diseases could include the elimination of biofilms and restoration of normal commensal bacteria populations. However, these studies will be extremely difficult unless investigators can develop noninvasive methods for measuring and identifying biofilms. These methods that might include the measurement of quorum sensing molecules, measurement of bile acids, and identification of bacteria uniquely associated with biofilms in the colon.
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9
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Arjes HA, Gui H, Porter R, Atolia E, Peters JM, Gross C, Kearns DB, Huang KC. Fatty Acid Synthesis Knockdown Promotes Biofilm Wrinkling and Inhibits Sporulation in Bacillus subtilis. mBio 2022; 13:e0138822. [PMID: 36069446 PMCID: PMC9600695 DOI: 10.1128/mbio.01388-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/05/2022] [Indexed: 02/05/2023] Open
Abstract
Many bacterial species typically live in complex three-dimensional biofilms, yet much remains unknown about differences in essential processes between nonbiofilm and biofilm lifestyles. Here, we created a CRISPR interference (CRISPRi) library of knockdown strains covering all known essential genes in the biofilm-forming Bacillus subtilis strain NCIB 3610 and investigated growth, biofilm colony wrinkling, and sporulation phenotypes of the knockdown library. First, we showed that gene essentiality is largely conserved between liquid and surface growth and between two media. Second, we quantified biofilm colony wrinkling using a custom image analysis algorithm and found that fatty acid synthesis and DNA gyrase knockdown strains exhibited increased wrinkling independent of biofilm matrix gene expression. Third, we designed a high-throughput screen to quantify sporulation efficiency after essential gene knockdown; we found that partial knockdowns of essential genes remained competent for sporulation in a sporulation-inducing medium, but knockdown of essential genes involved in fatty acid synthesis exhibited reduced sporulation efficiency in LB, a medium with generally lower levels of sporulation. We conclude that a subset of essential genes are particularly important for biofilm structure and sporulation/germination and suggest a previously unappreciated and multifaceted role for fatty acid synthesis in bacterial lifestyles and developmental processes. IMPORTANCE For many bacteria, life typically involves growth in dense, three-dimensional communities called biofilms that contain cells with differentiated roles held together by extracellular matrix. To examine how essential gene function varies between vegetative growth and the developmental states of biofilm formation and sporulation, we created and screened a comprehensive library of strains using CRISPRi to knockdown expression of each essential gene in the biofilm-capable Bacillus subtilis strain 3610. High-throughput assays and computational algorithms identified a subset of essential genes involved in biofilm wrinkling and sporulation and indicated that fatty acid synthesis plays important and multifaceted roles in bacterial development.
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Affiliation(s)
- Heidi A. Arjes
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
| | - Haiwen Gui
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
| | - Rachel Porter
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California, USA
| | - Esha Atolia
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
| | - Jason M. Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Carol Gross
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, USA
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California, USA
| | - Daniel B. Kearns
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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10
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Raz C, Paramonov MM, Shemesh M, Argov-Argaman N. The milk fat globule size governs a physiological switch for biofilm formation by Bacillus subtilis. Front Nutr 2022; 9:844587. [PMID: 36034896 PMCID: PMC9404525 DOI: 10.3389/fnut.2022.844587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 07/20/2022] [Indexed: 11/30/2022] Open
Abstract
Milk lipids are organized in the form of milk fat globules (MFG), ranging in size from 0. 1 to 15 μm. The MFG size is closely associated with the composition of fatty acids, polar lipids, sphingolipids, cholesterol and the content of the MFG membrane (MFGM). Also, the MFGM integral proteins and glycoconjugates differ in composition and structure between different MFG size groups. These compositional differences may modulate the functionality of the MFG and its interaction with microbial cells. We report that small (2.3 μm) MFG facilitates the growth of the Gram-positive bacterium Bacillus subtilis whereas induction of biofilm formation was found in the presence of large (7.0 μm) MFG. Attempting to distinguish between the role played by the size from that played by the composition of the MFG, we compared phospholipid composition between treatments. We found that adjusting the phosphatidylethanolamine (PE) level to the concentration found in the small MFG, increased growth but suppressed biofilm formation in the presence of large MFG. The same normalization protocol for phosphatidylinositol (PI) or sphingomyeline (SM) did not exert a similar effect, suggesting a specific role for PE in regulating bacteria proliferation. We suggest that the content of MFGM, affected by MFG size, governs the ability of B. subtilis to utilize lipids from milk fat. This process might affect the bacterial decision-making toward biofilm formation or growth.
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Affiliation(s)
- Chen Raz
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Food Sciences, Institute of Postharvest Technology and Food Sciences, The Volcani Institute, Agricultural Research Organization, Rishon LeZion, Israel
| | - Margarita Maggie Paramonov
- Department of Food Sciences, Institute of Postharvest Technology and Food Sciences, The Volcani Institute, Agricultural Research Organization, Rishon LeZion, Israel
| | - Moshe Shemesh
- Department of Food Sciences, Institute of Postharvest Technology and Food Sciences, The Volcani Institute, Agricultural Research Organization, Rishon LeZion, Israel
| | - Nurit Argov-Argaman
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
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11
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Bioremediation potential of hexavalent chromium-resistant Arthrobacter globiformis 151B: study of the uptake of cesium and other alkali ions. INTERNATIONAL MICROBIOLOGY : THE OFFICIAL JOURNAL OF THE SPANISH SOCIETY FOR MICROBIOLOGY 2022; 25:745-758. [PMID: 35768673 DOI: 10.1007/s10123-022-00258-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/04/2022] [Accepted: 06/07/2022] [Indexed: 10/17/2022]
Abstract
Cesium (Cs+) enters environments largely because of global release into the environment from weapons testing and accidents such as Fukushima Daiichi and Chernobyl nuclear waste. Even at low concentrations, Cs+ is highly toxic to ecological receptors because of its physicochemical similarity to macronutrient potassium (K+). We investigated the uptake and accumulation of Cs+ by Arthrobacter globiformis strain 151B in reference to three similar alkali metal cations rubidium (Rb+), sodium (Na+), and potassium (K+). The impact of hexavalent chromium (Cr+6) as a co-contaminant was also evaluated. A. globiformis 151B accumulated Cs+ and Cr6+ in a time-dependent fashion. In contrast, the uptake and accumulation of Rb+ did not exhibit any trends. An exposure to Cs+, Rb+, and Cr+6 triggered a drastic increase in K+ and Na+ uptake by the bacterial cells. That was followed by the efflux of K+ and Na+, suggesting a Cs+ "substitution." Two-dimensional gel-electrophoresis of bacterial cell proteomes with the following mass-spectrometry of differentially expressed bands revealed that incubation of bacterial cells with Cs+ induced changes in the expression of proteins involved in the maintenance of cellular homeostasis and reactive oxygen species removal. The ability of A. globiformis 151B to mediate the uptake and accumulation of cesium and hexavalent chromium suggests that it possesses wide-range bioremediation potential.
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12
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Zhang Y, Gallant É, Park JD, Seyedsayamdost MR. The Small-Molecule Language of Dynamic Microbial Interactions. Annu Rev Microbiol 2022; 76:641-660. [PMID: 35679616 PMCID: PMC10171915 DOI: 10.1146/annurev-micro-042722-091052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although microbes are routinely grown in monocultures in the laboratory, they are almost never encountered as single species in the wild. Our ability to detect and identify new microorganisms has advanced significantly in recent years, but our understanding of the mechanisms that mediate microbial interactions has lagged behind. What makes this task more challenging is that microbial alliances can be dynamic, consisting of multiple phases. The transitions between phases, and the interactions in general, are often mediated by a chemical language consisting of small molecules, also referred to as secondary metabolites or natural products. In this microbial lexicon, the molecules are like words and through their effects on recipient cells they convey meaning. The current review highlights three dynamic microbial interactions in which some of the words and their meanings have been characterized, especially those that mediate transitions in selected multiphasic associations. These systems provide insights into the principles that govern microbial symbioses and a playbook for interrogating similar associations in diverse ecological niches. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yifan Zhang
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA; ,
| | - Étienne Gallant
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
| | - Jong-Duk Park
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
| | - Mohammad R Seyedsayamdost
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA; , .,Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
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13
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Cohen-Cymberknoh M, Kolodkin-Gal D, Keren-Paz A, Peretz S, Brumfeld V, Kapishnikov S, Suissa R, Shteinberg M, McLeod D, Maan H, Patrauchan M, Zamir G, Kerem E, Kolodkin-Gal I. Calcium carbonate mineralization is essential for biofilm formation and lung colonization. iScience 2022; 25:104234. [PMID: 35521519 PMCID: PMC9062676 DOI: 10.1016/j.isci.2022.104234] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/18/2021] [Accepted: 04/07/2022] [Indexed: 11/27/2022] Open
Abstract
Biofilms are differentiated microbial communities held together by an extracellular matrix. μCT X-ray revealed structured mineralized areas within biofilms of lung pathogens belonging to two distant phyla - the proteobacteria Pseudomonas aeruginosa and the actinobacteria Mycobacterium abscessus. Furthermore, calcium chelation inhibited the assembly of complex bacterial structures for both organisms with little to no effect on cell growth. The molecular mechanisms promoting calcite scaffold formation were surprisingly conserved between the two pathogens as biofilm development was similarly impaired by genetic and biochemical inhibition of calcium uptake and carbonate accumulation. Moreover, chemical inhibition and mutations targeting mineralization significantly reduced the attachment of P. aeruginosa to the lung, as well as the subsequent damage inflicted by biofilms to lung tissues, and restored their sensitivity to antibiotics. This work offers underexplored druggable targets for antibiotics to combat otherwise untreatable biofilm infections.
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Affiliation(s)
- Malena Cohen-Cymberknoh
- Pediatric Pulmonary Unit and Cystic fibrosis Center, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Dror Kolodkin-Gal
- Department of Experimental Surgery, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- National Center for Antibiotic Resistance and Infection Control, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Shani Peretz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Vlad Brumfeld
- Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Kapishnikov
- Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Ronit Suissa
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Michal Shteinberg
- Pulmonology Institute and CF Center, Carmel Medical Center, Haifa, Israel
| | - Daniel McLeod
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Harsh Maan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Marianna Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Gideon Zamir
- Department of Experimental Surgery, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Eitan Kerem
- Pediatric Pulmonary Unit and Cystic fibrosis Center, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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14
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Ivo Ganchev. Role of Multispecies Biofilms with a Dominance of Bacillus subtilis in the Rhizosphere. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021150061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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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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16
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Aguilar C, Wissmann R, Fraefel C, Eichwald C. Display of Heterologous Proteins in Bacillus Subtilis Biofilms for Enteric Immunization. Methods Mol Biol 2022; 2465:73-95. [PMID: 35118616 DOI: 10.1007/978-1-0716-2168-4_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
One of the foremost goals in vaccine development is the design of effective, heat-stable vaccines that simplify the distribution and delivery while conferring high levels of protective immunity. Here, we describe a method for developing a live, oral vaccine that relies on the biofilm-forming properties of the spore-former bacterium Bacillus subtilis. The amyloid protein TasA is an abundant component of the extracellular matrix of the biofilms formed by B. subtilis that can be genetically fused to an antigen of interest. Spores of the recombinant strain are then prepared and applied via the oral route in an animal model. Due to the intrinsic resistance of the spores, they can bypass the stomach barrier, germinate, and subsequently colonize the gut, where they develop into biofilms, expressing the antigen of interest. We describe here the steps necessary to produce spores, immunization, and downstream analysis of the vaccine efficacy.
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Affiliation(s)
- Claudio Aguilar
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | - Ramona Wissmann
- Institute of Virology, University of Zurich, Zurich, Switzerland
| | - Cornel Fraefel
- Institute of Virology, University of Zurich, Zurich, Switzerland
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17
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Huang R, Feng H, Xu Z, Zhang N, Liu Y, Shao J, Shen Q, Zhang R. Identification of Adhesins in Plant Beneficial Rhizobacteria Bacillus velezensis SQR9 and Their Effect on Root Colonization. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:64-72. [PMID: 34698535 DOI: 10.1094/mpmi-09-21-0234-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Probiotic Bacillus colonization of plant root surfaces has been reported to improve its beneficial effect. Chemotaxis, adhesion, aggregation, and biofilm formation are the four steps of root colonization by plant growth-promoting rhizobacteria (PGPRs). Compared with the other three well-studied processes, adhesion of PGPRs is less known. In this study, using mutant strains deleted for potential adhesin genes in PGPR strain Bacillus velezensis SQR9, adherence to both cucumber root surface and abiotic surface by those strains was evaluated. Results showed that deletion mutations ΔlytB, ΔV529_10500, ΔfliD, ΔyhaN, and ΔsacB reduced the adhesion to root surfaces, while, among them, only ΔfliD had significant defects in adhesion to abiotic surfaces (glass and polystyrene). In addition, B. velevzensis SQR9 mutants defective in adhesion to root surfaces showed a deficiency in rhizosphere colonization. Among the encoded proteins, FliD and YhaN played vital roles in root adhesion. This research systematically explored the potential adhesins in a well-studied PGPR strain and also indicated that adhesion progress was required for root colonization, which will help to enhance rhizosphere colonization and beneficial function of PGPRs in agricultural production.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Rong Huang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Haichao Feng
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Zhihui Xu
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Nan Zhang
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Yunpeng Liu
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
| | - Jiahui Shao
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Qirong Shen
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Ruifu Zhang
- Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R. China
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18
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Maan H, Povolotsky TL, Porat Z, Itkin M, Malitsky S, Kolodkin-Gal I. Imaging flow cytometry reveals a dual role for exopolysaccharides in biofilms: To promote self-adhesion while repelling non-self-community members. Comput Struct Biotechnol J 2021; 20:15-25. [PMID: 34976308 PMCID: PMC8666610 DOI: 10.1016/j.csbj.2021.11.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022] Open
Abstract
In nature, bacteria frequently reside in differentiated communities or biofilms. These multicellular communities are held together by self-produced polymers that allow the community members to adhere to the surface as well as to neighbor bacteria. Here, we report that exopolysaccharides prevent Bacillus subtilis from co-aggregating with a distantly related bacterium Bacillus mycoides, while maintaining their role in promoting self-adhesion and co-adhesion with phylogenetically related bacterium, Bacillus atrophaeus. The defensive role of the exopolysaccharides is due to the specific regulation of bacillaene. Single cell analysis of biofilm and free-living bacterial cells using imaging flow cytometry confirmed a specific role for the exopolysaccharides in microbial competition repelling B. mycoides. Unlike exopolysaccharides, the matrix protein TasA induced bacillaene but inhibited the expression of the biosynthetic clusters for surfactin, and therefore its overall effect on microbial competition during floating biofilm formation was neutral. Thus, the exopolysaccharides provide a dual fitness advantage for biofilm-forming cells, as it acts to promote co-aggregation of related species, as well as, a secreted cue for chemical interference with non-compatible partners. These results experimentally demonstrate a general assembly principle of complex communities and provides an appealing explanation for how closely related species are favored during community assembly. Furthermore, the differential regulation of surfactin and bacillaene by the extracellular matrix may explain the spatio-temporal gradients of antibiotic production within biofilms.
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Affiliation(s)
- Harsh Maan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | | | - Ziv Porat
- Flow Cytometry Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Maxim Itkin
- Life Science Core Facilities Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Sergey Malitsky
- Life Science Core Facilities Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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19
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Rahman FB, Sarkar B, Moni R, Rahman MS. Molecular genetics of surfactin and its effects on different sub-populations of Bacillus subtilis. ACTA ACUST UNITED AC 2021; 32:e00686. [PMID: 34786355 PMCID: PMC8578018 DOI: 10.1016/j.btre.2021.e00686] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/28/2021] [Accepted: 10/20/2021] [Indexed: 11/19/2022]
Abstract
Insight into the role of surfactin on B. subtilis cell differentiation. Insight into the molecular genetics of surfactin and its production. Graphical presentation of surfactin mediated signaling cascades via quorum sensing.
Surfactin is a biosurfactant produced by Bacillus subtilis. The srfA operon, Sfp gene, and two quorum sensing systems are required for its production. The master regulator spo0A also plays an indispensable role in proper surfactin synthesis. Upon production, surfactin itself acts as a signaling molecule and triggers the activation of Spo0A gene which in turn regulates cell differentiation. Interestingly, surfactin producing cells are immune to the action of surfactin but trigger other cells to differentiate into non-motile cells, matrix producing cells, cannibals, and spores. In case of competent cell differentiation, comS, which resides within the srfA operon, is co-expressed along with surfactin and plays a vital role in competent cell differentiation in response to quorum sensing signal. Surfactin inhibits the motility of certain cell subpopulations, although it helps the non-motile cells to swarm. Thus, surfactin plays significant roles in the differentiation of different subpopulations of specialized cell types of B. subtilis.
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Affiliation(s)
- Faisal Bin Rahman
- Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh
| | - Bishajit Sarkar
- Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh
- Wazed Miah Science Research Center (WMSRC), Jahangirnagar University, Savar, Dhaka, Bangladesh
| | - Ripa Moni
- Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh
| | - Mohammad Shahedur Rahman
- Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh
- Wazed Miah Science Research Center (WMSRC), Jahangirnagar University, Savar, Dhaka, Bangladesh
- Corresponding author.
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20
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Abstract
Microbes inhabit ever-changing environments in which the conditions for propagation, whether they be favorable or unfavorable, are often transient. Plants and animals are able to cope with changing circumstances in their external environment by maintaining homeostasis for internal cells, tissues and organs. Microbes do not have this luxury. Instead, they have evolved mechanisms for adapting to change by being versatile. In some cases, these adaptations involve the expression of a limited set of genes that exploit the availability of a food source or provide protection against chemical, radiation or thermal stress. In other cases, however, microbes adapt in a more elaborate manner by entering a specialized state that enables them to exploit a particular niche or protects them against environmental extremes. Entry into such a state can occur as a direct response to an external cue or stochastically (by chance) as part of a bet-hedging strategy, or sometimes a combination of the two. An example of a versatile microbe that exhibits a wide variety of states is the bacterium Bacillus subtilis, the subject of this Primer. Many of the states exhibited by B. subtilis are similar to states observed in other bacteria. What is special about B. subtilis is the unusually rich repertoire of alternative states exhibited by one bacterium, enabling it to cope with a wide range of environmental challenges.
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Affiliation(s)
- Richard M Losick
- The Biological Laboratories, Harvard University, Cambridge, MA 02138, USA.
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21
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Lyon P, Keijzer F, Arendt D, Levin M. Reframing cognition: getting down to biological basics. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190750. [PMID: 33487107 PMCID: PMC7935032 DOI: 10.1098/rstb.2019.0750] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2020] [Indexed: 12/12/2022] Open
Abstract
The premise of this two-part theme issue is simple: the cognitive sciences should join the rest of the life sciences in how they approach the quarry within their research domain. Specifically, understanding how organisms on the lower branches of the phylogenetic tree become familiar with, value and exploit elements of an ecological niche while avoiding harm can be expected to aid understanding of how organisms that evolved later (including Homo sapiens) do the same or similar things. We call this approach basal cognition. In this introductory essay, we explain what the approach involves. Because no definition of cognition exists that reflects its biological basis, we advance a working definition that can be operationalized; introduce a behaviour-generating toolkit of capacities that comprise the function (e.g. sensing/perception, memory, valence, learning, decision making, communication), each element of which can be studied relatively independently; and identify a (necessarily incomplete) suite of common biophysical mechanisms found throughout the domains of life involved in implementing the toolkit. The articles in this collection illuminate different aspects of basal cognition across different forms of biological organization, from prokaryotes and single-celled eukaryotes-the focus of Part 1-to plants and finally to animals, without and with nervous systems, the focus of Part 2. By showcasing work in diverse, currently disconnected fields, we hope to sketch the outline of a new multidisciplinary approach for comprehending cognition, arguably the most fascinating and hard-to-fathom evolved function on this planet. Doing so has the potential to shed light on problems in a wide variety of research domains, including microbiology, immunology, zoology, biophysics, botany, developmental biology, neurobiology/science, regenerative medicine, computational biology, artificial life and synthetic bioengineering. This article is part of the theme issue 'Basal cognition: conceptual tools and the view from the single cell'.
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Affiliation(s)
- Pamela Lyon
- Southgate Institute for Health, Society and Equity, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia
| | - Fred Keijzer
- Department of Theoretical Philosophy, Universityof Groningen, Oude Boteringestraat 52, Groningen 9712GL, The Netherlands
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69012 Heidelberg, Germany
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
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22
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Li C, Cheng P, Zheng L, Li Y, Chen Y, Wen S, Yu G. Comparative genomics analysis of two banana Fusarium wilt biocontrol endophytes Bacillus subtilis R31 and TR21 provides insights into their differences on phytobeneficial trait. Genomics 2021; 113:900-909. [PMID: 33592313 DOI: 10.1016/j.ygeno.2021.02.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/26/2020] [Accepted: 02/08/2021] [Indexed: 01/27/2023]
Abstract
Fusarium wilt of banana is considered one of the most destructive plant diseases. Bacillus subtilis R31 and TR21, isolated from Dendrobium sp. leaves, exhibit different phytobeneficial effects on banana Fusarium wilt bio-controlling. Here, we performed genome sequencing and comparative genomics analysis of R31 and TR21 to enhance our understanding of the different phytobeneficial traits. These results revealed that the strain-specific genes of R31 involved in sporulation, quorum sensing, and antibiotic synthesis allow R31 to present a better capacity of sporulation, rhizosphere adaptation, and quorum sensing than TR21. Selective pressure analysis indicated that the glycosylase and endo-alpha-(1- > 5)-L-arabinanase genes were strong positive selected, which may contribute to the TR21 to colonize well in banana's vascular bundles. Altogether, our findings presented here should advance further agricultural application of R31 and TR21 as two promising resources of plant growth promotion and biological control via genetic engineering.
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Affiliation(s)
- Chunji Li
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China.
| | - Ping Cheng
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China.
| | - Li Zheng
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China
| | - Yongjian Li
- Zhuhai Modern Agriculture Development Center, Zhuhai 519075, People's Republic of China
| | - Yanhong Chen
- Zhuhai Modern Agriculture Development Center, Zhuhai 519075, People's Republic of China
| | - Shuheng Wen
- Guangdong Geolong Biotechnology Co., Ltd., Zhuhai 519050, People's Republic of China
| | - Guohui Yu
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, People's Republic of China.
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23
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Hou Q, Keren-Paz A, Korenblum E, Oved R, Malitsky S, Kolodkin-Gal I. Weaponizing volatiles to inhibit competitor biofilms from a distance. NPJ Biofilms Microbiomes 2021; 7:2. [PMID: 33402677 PMCID: PMC7785731 DOI: 10.1038/s41522-020-00174-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 11/19/2020] [Indexed: 01/29/2023] Open
Abstract
The soil bacterium Bacillus subtilis forms beneficial biofilms that induce plant defences and prevent the growth of pathogens. It is naturally found in the rhizosphere, where microorganisms coexist in an extremely competitive environment, and thus have evolved a diverse arsenal of defence mechanisms. In this work, we found that volatile compounds produced by B. subtilis biofilms inhibited the development of competing biofilm colonies, by reducing extracellular matrix gene expression, both within and across species. This effect was dose-dependent, with the structural defects becoming more pronounced as the number of volatile-producing colonies increased. This inhibition was mostly mediated by organic volatiles, and we identified the active molecules as 3-methyl-1-butanol and 1-butanol. Similar results were obtained with biofilms formed by phylogenetically distinct bacterium sharing the same niche, Escherichia coli, which produced the biofilm-inhibiting 3-methyl-1-butanol and 2-nonanon. The ability of established biofilms to inhibit the development and spreading of new biofilms from afar might be a general mechanism utilized by bacterial biofilms to protect an occupied niche from the invasion of competing bacteria.
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Affiliation(s)
- Qihui Hou
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Alona Keren-Paz
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Elisa Korenblum
- grid.13992.300000 0004 0604 7563Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Rela Oved
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- grid.13992.300000 0004 0604 7563Metabolic Profiling Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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24
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Emerging Roles of Functional Bacterial Amyloids in Gene Regulation, Toxicity, and Immunomodulation. Microbiol Mol Biol Rev 2020; 85:85/1/e00062-20. [PMID: 33239434 DOI: 10.1128/mmbr.00062-20] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria often reside in multicellular communities, called biofilms, held together by an extracellular matrix. In many bacteria, the major proteinaceous component of the biofilm are amyloid fibers. Amyloids are highly stable and structured protein aggregates which were known mostly to be associated with neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases. In recent years, microbial amyloids were identified also in other species and shown to play major roles in microbial physiology and virulence. For example, amyloid fibers assemble on the bacterial cell surface as a part of the extracellular matrix and are extremely important to the scaffolding and structural integrity of biofilms, which contribute to microbial resilience and resistance. Furthermore, microbial amyloids play fundamental nonscaffold roles that contribute to the development of biofilms underlying numerous persistent infections. Here, we review several nonscaffold roles of bacterial amyloid proteins, including bridging cells during collective migration, acting as regulators of cell fate, as toxins against other bacteria or against host immune cells, and as modulators of the hosts' immune system. These overall points on the complexity of the amyloid fold in encoding numerous activities, which offer approaches for the development of a novel repertoire of antivirulence therapeutics.
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25
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Rodriguez Ayala F, Bartolini M, Grau R. The Stress-Responsive Alternative Sigma Factor SigB of Bacillus subtilis and Its Relatives: An Old Friend With New Functions. Front Microbiol 2020; 11:1761. [PMID: 33042030 PMCID: PMC7522486 DOI: 10.3389/fmicb.2020.01761] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022] Open
Abstract
Alternative sigma factors have led the core RNA polymerase (RNAP) to recognize different sets of promoters to those recognized by the housekeeping sigma A-directed RNAP. This change in RNAP promoter selectivity allows a rapid and flexible reformulation of the genetic program to face environmental and metabolic stimuli that could compromise bacterial fitness. The model bacterium Bacillus subtilis constitutes a matchless living system in the study of the role of alternative sigma factors in gene regulation and physiology. SigB from B. subtilis was the first alternative sigma factor described in bacteria. Studies of SigB during the last 40 years have shown that it controls a genetic universe of more than 150 genes playing crucial roles in stress response, adaption, and survival. Activation of SigB relies on three separate pathways that specifically respond to energy, environmental, and low temperature stresses. SigB homologs, present in other Gram-positive bacteria, also play important roles in virulence against mammals. Interestingly, during recent years, other unexpected B. subtilis responses were found to be controlled by SigB. In particular, SigB controls the efficiencies of spore and biofilm formation, two important features that play critical roles in adaptation and survival in planktonic and sessile B. subtilis communities. In B. subtilis, SigB induces the expression of the Spo0E aspartyl-phosphatase, which is responsible for the blockage of sporulation initiation. The upregulated activity of Spo0E connects the two predominant adaptive pathways (i.e., sporulation and stress response) present in B. subtilis. In addition, the RsbP serine-phosphatase, belonging to the energy stress arm of the SigB regulatory cascade, controls the expression of the key transcription factor SinR to decide whether cells residing in the biofilm remain in and maintain biofilm growth or scape to colonize new niches through biofilm dispersal. SigB also intervenes in the recognition of and response to surrounding microorganisms, a new SigB role that could have an agronomic impact. SigB is induced when B. subtilis is confronted with phytopathogenic fungi (e.g., Fusarium verticillioides) and halts fungal growth to the benefit of plant growth. In this article, we update and review literature on the different regulatory networks that control the activation of SigB and the new roles that have been described the recent years.
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Affiliation(s)
- Facundo Rodriguez Ayala
- Departamento de Micro y Nanotecnología, Instituto de Nanociencia y Nanotecnología - Comisión Nacional de Energía Atómica (CNEA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marco Bartolini
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Roberto Grau
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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26
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Steinberg N, Keren-Paz A, Hou Q, Doron S, Yanuka-Golub K, Olender T, Hadar R, Rosenberg G, Jain R, Cámara-Almirón J, Romero D, van Teeffelen S, Kolodkin-Gal I. The extracellular matrix protein TasA is a developmental cue that maintains a motile subpopulation within Bacillus subtilis biofilms. Sci Signal 2020; 13:13/632/eaaw8905. [PMID: 32430292 DOI: 10.1126/scisignal.aaw8905] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In nature, bacteria form biofilms-differentiated multicellular communities attached to surfaces. Within these generally sessile biofilms, a subset of cells continues to express motility genes. We found that this subpopulation enabled Bacillus subtilis biofilms to expand on high-friction surfaces. The extracellular matrix (ECM) protein TasA was required for the expression of flagellar genes. In addition to its structural role as an adhesive fiber for cell attachment, TasA acted as a developmental signal stimulating a subset of biofilm cells to revert to a motile phenotype. Transcriptomic analysis revealed that TasA stimulated the expression of a specific subset of genes whose products promote motility and repress ECM production. Spontaneous suppressor mutations that restored motility in the absence of TasA revealed that activation of the biofilm-motility switch by the two-component system CssR/CssS antagonized the TasA-mediated reversion to motility in biofilm cells. Our results suggest that although mostly sessile, biofilms retain a degree of motility by actively maintaining a motile subpopulation.
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Affiliation(s)
- Nitai Steinberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.,Department of Microbiology, Institute Pasteur, Paris, France
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Qihui Hou
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Shany Doron
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Keren Yanuka-Golub
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rotem Hadar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gili Rosenberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rakeshkumar Jain
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Jesus Cámara-Almirón
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Diego Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | | | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
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27
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Keren-Paz A, Kolodkin-Gal I. A brick in the wall: Discovering a novel mineral component of the biofilm extracellular matrix. N Biotechnol 2020; 56:9-15. [DOI: 10.1016/j.nbt.2019.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/01/2019] [Accepted: 11/02/2019] [Indexed: 01/09/2023]
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28
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Mukherjee S, Bassler BL. Bacterial quorum sensing in complex and dynamically changing environments. Nat Rev Microbiol 2020; 17:371-382. [PMID: 30944413 DOI: 10.1038/s41579-019-0186-5] [Citation(s) in RCA: 550] [Impact Index Per Article: 137.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Quorum sensing is a process of bacterial cell-to-cell chemical communication that relies on the production, detection and response to extracellular signalling molecules called autoinducers. Quorum sensing allows groups of bacteria to synchronously alter behaviour in response to changes in the population density and species composition of the vicinal community. Quorum-sensing-mediated communication is now understood to be the norm in the bacterial world. Elegant research has defined quorum-sensing components and their interactions, for the most part, under ideal and highly controlled conditions. Indeed, these seminal studies laid the foundations for the field. In this Review, we highlight new findings concerning how bacteria deploy quorum sensing in realistic scenarios that mimic nature. We focus on how quorums are detected and how quorum sensing controls group behaviours in complex and dynamically changing environments such as multi-species bacterial communities, in the presence of flow, in 3D non-uniform biofilms and in hosts during infection.
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Affiliation(s)
- Sampriti Mukherjee
- Princeton University, Department of Molecular Biology, Princeton, NJ, USA
| | - Bonnie L Bassler
- Princeton University, Department of Molecular Biology, Princeton, NJ, USA. .,Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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29
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Cherukuri P, Songkiatisak P, Ding F, Jault JM, Xu XHN. Antibiotic Drug Nanocarriers for Probing of Multidrug ABC Membrane Transporter of Bacillus subtilis. ACS OMEGA 2020; 5:1625-1633. [PMID: 32010837 PMCID: PMC6990642 DOI: 10.1021/acsomega.9b03698] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/31/2019] [Indexed: 06/10/2023]
Abstract
Multidrug membrane transporters can extrude a wide range of substrates, which cause multidrug resistance and ineffective treatment of diseases. In this study, we used three different sized antibiotic drug nanocarriers to study their size-dependent inhibitory effects against Bacillus subtilis. We functionalized 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm silver nanoparticles (Ag NPs) with a monolayer of 11-amino-1-undecanethiol and covalently linked them with antibiotics (ofloxacin, Oflx). The labeling ratios of antibiotics with NPs are 8.6 × 102, 9.4 × 103, and 6.5 × 105 Oflx molecules per NP, respectively. We designed cell culture medium in which both BmrA and ΔBmrA cells grew and functioned normally while ensuring the stabilities of nanocarriers (nonaggregation). These approaches allow us to quantitatively study the dependence of their inhibitory effect against two isogenic strains of B. subtilis, WT (normal expression of BmrA) and ΔBmrA (deletion of bmrA), upon the NP size, antibiotic dose, and BmrA expression. Our results show that the inhibitory effects of nanocarriers highly depend on NP size and antibiotic dose. The same amount of Oflx on 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm nanocarriers shows the 3× lower, nearly the same, and 10× higher inhibitory effects than that of free Oflx, against both WT and ΔBmrA, respectively. Control experiments of the respective sized AgMUNH2 NPs (absence of Oflx) show insignificant inhibitory effects toward both strains. Taken together, the results show multiple factors, such as labeling ratios, multivalent effects, and pharmacodynamics (Oflx localization and distribution), which might play the roles in the size-dependent inhibitory effects on the growth of both WT and ΔBmrA strains. Interestingly, the inhibitory effects of nanocarriers are independent of the expression of BmrA, which could be attributed to the higher efflux of nanocarriers by other membrane transporters in both strains.
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Affiliation(s)
- Pavan
Kumar Cherukuri
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529, United States
| | - Preeyaporn Songkiatisak
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529, United States
| | - Feng Ding
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529, United States
| | - Jean-Michel Jault
- UMR5086
CNRS/UCBLyon I, MMSB-IBCP, 7 Passage du Vercors, 69367 Lyon cedex 07, France
| | - Xiao-Hong Nancy Xu
- Department
of Chemistry and Biochemistry, Old Dominion
University, Norfolk, Virginia 23529, United States
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30
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Progress in research and application development of surface display technology using Bacillus subtilis spores. Appl Microbiol Biotechnol 2020; 104:2319-2331. [PMID: 31989224 PMCID: PMC7223921 DOI: 10.1007/s00253-020-10348-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/16/2019] [Accepted: 01/03/2020] [Indexed: 02/02/2023]
Abstract
Bacillus subtilis is a widely distributed aerobic Gram-positive species of bacteria. As a tool in the lab, it has the advantages of nonpathogenicity and limited likelihood of becoming drug resistant. It is a probiotic strain that can be directly used in humans and animals. It can be induced to produce spores under nutrient deficiency or other adverse conditions. B. subtilis spores have unique physical, chemical, and biochemical characteristics. Expression of heterologous antigens or proteins on the surface of B. subtilis spores has been successfully performed for over a decade. As an update and supplement to previously published research, this paper reviews the latest research on spore surface display technology using B. subtilis. We have mainly focused on the regulation of spore coat protein expression, display and application of exogenous proteins, and identification of developing research areas of spore surface display technology.
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31
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Rivera‐Yoshida N, Hernández‐Terán A, Escalante AE, Benítez M. Laboratory biases hinder Eco‐Evo‐Devo integration: Hints from the microbial world. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 334:14-24. [DOI: 10.1002/jez.b.22917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Natsuko Rivera‐Yoshida
- Laboratorio Nacional de Ciencias de la Sostenibilidad (LANCIS), Instituto de EcologíaUniversidad Nacional Autónoma de México Mexico City Mexico
- Programa de Doctorado en Ciencias BiomédicasUniversidad Nacional Autónoma de México Mexico City Mexico
- Centro de Ciencias de la ComplejidadUniversidad Nacional Autónoma de México Mexico City Mexico
| | - Alejandra Hernández‐Terán
- Laboratorio Nacional de Ciencias de la Sostenibilidad (LANCIS), Instituto de EcologíaUniversidad Nacional Autónoma de México Mexico City Mexico
- Programa de Doctorado en Ciencias BiomédicasUniversidad Nacional Autónoma de México Mexico City Mexico
| | - Ana E. Escalante
- Laboratorio Nacional de Ciencias de la Sostenibilidad (LANCIS), Instituto de EcologíaUniversidad Nacional Autónoma de México Mexico City Mexico
| | - Mariana Benítez
- Laboratorio Nacional de Ciencias de la Sostenibilidad (LANCIS), Instituto de EcologíaUniversidad Nacional Autónoma de México Mexico City Mexico
- Centro de Ciencias de la ComplejidadUniversidad Nacional Autónoma de México Mexico City Mexico
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32
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Qin Y, He Y, She Q, Larese-Casanova P, Li P, Chai Y. Heterogeneity in respiratory electron transfer and adaptive iron utilization in a bacterial biofilm. Nat Commun 2019; 10:3702. [PMID: 31420537 PMCID: PMC6697725 DOI: 10.1038/s41467-019-11681-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/26/2019] [Indexed: 11/16/2022] Open
Abstract
In Bacillus subtilis, robust biofilm formation requires large quantities of ferric iron. Here we show that this process requires preferential production of a siderophore precursor, 2,3-dihydroxybenzoate, instead of the siderophore bacillibactin. A large proportion of iron is associated extracellularly with the biofilm matrix. The biofilms are conductive, with extracellular iron potentially acting as electron acceptor. A relatively small proportion of ferric iron is internalized and boosts production of iron-containing enzymes involved in respiratory electron transfer and establishing strong membrane potential, which is key to biofilm matrix production. Our study highlights metabolic diversity and versatile energy generation strategies within B. subtilis biofilms. Biofilm formation in Bacillus subtilis requires high levels of ferric iron. Here, Qin et al. show that iron accumulation requires production of dihydroxybenzoate (a precursor in siderophore biosynthesis), and matrix-associated iron may be acting as extracellular electron acceptor during respiratory electron transfer.
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Affiliation(s)
- Yuxuan Qin
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.,Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Yinghao He
- Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Qianxuan She
- Department of Biology, Northeastern University, Boston, MA, 02115, USA
| | - Philip Larese-Casanova
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, 02115, USA
| | - Pinglan Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA, 02115, USA.
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33
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Weiss CA, Hoberg JA, Liu K, Tu BP, Winkler WC. Single-Cell Microscopy Reveals That Levels of Cyclic di-GMP Vary among Bacillus subtilis Subpopulations. J Bacteriol 2019; 201:e00247-19. [PMID: 31138629 PMCID: PMC6657594 DOI: 10.1128/jb.00247-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/21/2019] [Indexed: 11/20/2022] Open
Abstract
The synthesis of signaling molecules is one strategy bacteria employ to sense alterations in their environment and rapidly adjust to those changes. In Gram-negative bacteria, bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) regulates the transition from a unicellular motile state to a multicellular sessile state. However, c-di-GMP signaling has been less intensively studied in Gram-positive organisms. To that end, we constructed a fluorescent yfp reporter based on a c-di-GMP-responsive riboswitch to visualize the relative abundance of c-di-GMP for single cells of the Gram-positive model organism Bacillus subtilis Coupled with cell-type-specific fluorescent reporters, this riboswitch reporter revealed that c-di-GMP levels are markedly different among B. subtilis cellular subpopulations. For example, cells that have made the decision to become matrix producers maintain higher intracellular c-di-GMP concentrations than motile cells. Similarly, we find that c-di-GMP levels differ between sporulating and competent cell types. These results suggest that biochemical measurements of c-di-GMP abundance are likely to be inaccurate for a bulk ensemble of B. subtilis cells, as such measurements will average c-di-GMP levels across the population. Moreover, the significant variation in c-di-GMP levels between cell types hints that c-di-GMP might play an important role during B. subtilis biofilm formation. This study therefore emphasizes the importance of using single-cell approaches for analyzing metabolic trends within ensemble bacterial populations.IMPORTANCE Many bacteria have been shown to differentiate into genetically identical yet morphologically distinct cell types. Such population heterogeneity is especially prevalent among biofilms, where multicellular communities are primed for unexpected environmental conditions and can efficiently distribute metabolic responsibilities. Bacillus subtilis is a model system for studying population heterogeneity; however, a role for c-di-GMP in these processes has not been thoroughly investigated. Herein, we introduce a fluorescent reporter, based on a c-di-GMP-responsive riboswitch, to visualize the relative abundance of c-di-GMP for single B. subtilis cells. Our analysis shows that c-di-GMP levels are conspicuously different among B. subtilis cellular subtypes, suggesting a role for c-di-GMP during biofilm formation. These data highlight the utility of riboswitches as tools for imaging metabolic changes within individual bacterial cells. Analyses such as these offer new insight into c-di-GMP-regulated phenotypes, especially given that other biofilms also consist of multicellular communities.
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Affiliation(s)
- Cordelia A Weiss
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Jakob A Hoberg
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Kuanqing Liu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Benjamin P Tu
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Wade C Winkler
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
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34
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van Gestel J, Ackermann M, Wagner A. Microbial life cycles link global modularity in regulation to mosaic evolution. Nat Ecol Evol 2019; 3:1184-1196. [PMID: 31332330 DOI: 10.1038/s41559-019-0939-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 06/03/2019] [Indexed: 11/09/2022]
Abstract
Microbes are exposed to changing environments, to which they can respond by adopting various lifestyles such as swimming, colony formation or dormancy. These lifestyles are often studied in isolation, thereby giving a fragmented view of the life cycle as a whole. Here, we study lifestyles in the context of this whole. We first use machine learning to reconstruct the expression changes underlying life cycle progression in the bacterium Bacillus subtilis, based on hundreds of previously acquired expression profiles. This yields a timeline that reveals the modular organization of the life cycle. By analysing over 380 Bacillales genomes, we then show that life cycle modularity gives rise to mosaic evolution in which life stages such as motility and sporulation are conserved and lost as discrete units. We postulate that this mosaic conservation pattern results from habitat changes that make these life stages obsolete or detrimental. Indeed, when evolving eight distinct Bacillales strains and species under laboratory conditions that favour colony growth, we observe rapid and parallel losses of the sporulation life stage across species, induced by mutations that affect the same global regulator. We conclude that a life cycle perspective is pivotal to understanding the causes and consequences of modularity in both regulation and evolution.
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Affiliation(s)
- Jordi van Gestel
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland. .,Swiss Institute of Bioinformatics, Lausanne, Switzerland. .,Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland. .,Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland.
| | - Martin Ackermann
- Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland.,Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Andreas Wagner
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland. .,Swiss Institute of Bioinformatics, Lausanne, Switzerland. .,The Santa Fe Institute, Santa Fe, NM, USA.
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35
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Ogran A, Yardeni EH, Keren-Paz A, Bucher T, Jain R, Gilhar O, Kolodkin-Gal I. The Plant Host Induces Antibiotic Production To Select the Most-Beneficial Colonizers. Appl Environ Microbiol 2019; 85:e00512-19. [PMID: 31003984 PMCID: PMC6581183 DOI: 10.1128/aem.00512-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022] Open
Abstract
Microbial ecosystems tightly associated with a eukaryotic host are widespread in nature. The genetic and metabolic networks of the eukaryotic hosts and the associated microbes have coevolved to form a symbiotic relationship. Both the Gram-positive Bacillus subtilis and the Gram-negative Serratia plymuthica can form biofilms on plant roots and thus can serve as a model system for the study of interspecies interactions in a host-associated ecosystem. We found that B. subtilis biofilms expand collectively and asymmetrically toward S. plymuthica, while expressing a nonribosomal antibiotic bacillaene and an extracellular protease. As a result, B. subtilis biofilms outcompeted S. plymuthica for successful colonization of the host. Strikingly, the plant host was able to enhance the efficiency of this killing by inducing bacillaene synthesis. In turn, B. subtilis biofilms increased the resistance of the plant host to pathogens. These results provide an example of how plant-bacterium symbiosis promotes the immune response of the plant host and the fitness of the associated bacteria.IMPORTANCE Our study sheds mechanistic light on how multicellular biofilm units compete to successfully colonize a eukaryote host, using B. subtilis microbial communities as our lens. The microbiota and its interactions with its host play various roles in the development and prevention of diseases. Using competing beneficial biofilms that are essential microbiota members on the plant host, we found that B. subtilis biofilms activate collective migration to capture their prey, followed by nonribosomal antibiotic synthesis. Plant hosts increase the efficiency of antibiotic production by B. subtilis biofilms, as they activate the synthesis of polyketides; therefore, our study provides evidence of a mechanism by which the host can indirectly select for beneficial microbiota members.
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Affiliation(s)
- Ariel Ogran
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eliane Hadas Yardeni
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tabitha Bucher
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rakeshkumar Jain
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Omri Gilhar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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36
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Lee LM, Rosenberg G, Rubinstein SM. A Sequence of Developmental Events Occurs Underneath Growing Bacillus subtilis Pellicles. Front Microbiol 2019; 10:842. [PMID: 31105657 PMCID: PMC6499031 DOI: 10.3389/fmicb.2019.00842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/02/2019] [Indexed: 01/18/2023] Open
Abstract
Biofilms are structured communities of bacteria that exhibit complex spatio-temporal dynamics. In liquid media, Bacillus subtilis produces an opaque floating biofilm, or a pellicle. Biofilms are generally associated with an interface, but the ability of Bacillus subtilis to swim means the bacteria are additionally able to reside within the liquid phase. However, due to imaging complications associated with the opacity of pellicles, the extent to which bacteria coexist within the liquid bulk as well as their behavior in the liquid is not well studied. We therefore develop a high-throughput imaging system to image underneath developing pellicles. Here we report a well-defined sequence of developmental events that occurs underneath a growing pellicle. Comparison with bacteria deficient in swimming and chemotaxis suggest that these properties enable collective bacterial swimming within the liquid phase which facilitate faster surface colonization. Furthermore, comparison to bacteria deficient in exopolymeric substances (EPS) suggest that the lack of a surface pellicle prevents further developmental steps from occurring within the liquid phase. Our results reveal a sequence of developmental events during pellicle growth, encompassing adhesion, conversion, growth, maturity, and detachment on the interface, which are synchronized with the bacteria in the liquid bulk increasing in density until the formation of a mature surface pellicle, after which the density of bacteria in the liquid drops.
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Affiliation(s)
- Lisa M Lee
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States.,Kavli Institute for Bionano Science and Technology, Cambridge, MA, United States
| | - Gili Rosenberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Shmuel M Rubinstein
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States.,Kavli Institute for Bionano Science and Technology, Cambridge, MA, United States
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37
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Abstract
Bacterial biofilms are ubiquitous in natural environments and play an important role in many clinical, industrial, and ecological settings. Although much is known about the transcriptional regulatory networks that control biofilm formation in model bacteria such as Bacillus subtilis, very little is known about the role of metabolism in this complex developmental process. To address this important knowledge gap, we performed a time-resolved analysis of the metabolic changes associated with bacterial biofilm development in B. subtilis by combining metabolomic, transcriptomic, and proteomic analyses. Here, we report a widespread and dynamic remodeling of metabolism affecting central carbon metabolism, primary biosynthetic pathways, fermentation pathways, and secondary metabolism. This report serves as a unique hypothesis-generating resource for future studies on bacterial biofilm physiology. Outside the biofilm research area, this work should also prove relevant to any investigators interested in microbial physiology and metabolism. Biofilms are structured communities of tightly associated cells that constitute the predominant state of bacterial growth in natural and human-made environments. Although the core genetic circuitry that controls biofilm formation in model bacteria such as Bacillus subtilis has been well characterized, little is known about the role that metabolism plays in this complex developmental process. Here, we performed a time-resolved analysis of the metabolic changes associated with pellicle biofilm formation and development in B. subtilis by combining metabolomic, transcriptomic, and proteomic analyses. We report surprisingly widespread and dynamic remodeling of metabolism affecting central carbon metabolism, primary biosynthetic pathways, fermentation pathways, and secondary metabolism. Most of these metabolic alterations were hitherto unrecognized as biofilm associated. For example, we observed increased activity of the tricarboxylic acid (TCA) cycle during early biofilm growth, a shift from fatty acid biosynthesis to fatty acid degradation, reorganization of iron metabolism and transport, and a switch from acetate to acetoin fermentation. Close agreement between metabolomic, transcriptomic, and proteomic measurements indicated that remodeling of metabolism during biofilm development was largely controlled at the transcriptional level. Our results also provide insights into the transcription factors and regulatory networks involved in this complex metabolic remodeling. Following upon these results, we demonstrated that acetoin production via acetolactate synthase is essential for robust biofilm growth and has the dual role of conserving redox balance and maintaining extracellular pH. This report represents a comprehensive systems-level investigation of the metabolic remodeling occurring during B. subtilis biofilm development that will serve as a useful road map for future studies on biofilm physiology.
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38
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Serra DO, Hengge R. A c-di-GMP-Based Switch Controls Local Heterogeneity of Extracellular Matrix Synthesis which Is Crucial for Integrity and Morphogenesis of Escherichia coli Macrocolony Biofilms. J Mol Biol 2019; 431:4775-4793. [PMID: 30954572 DOI: 10.1016/j.jmb.2019.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 03/26/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022]
Abstract
The extracellular matrix in macrocolony biofilms of Escherichia coli is arranged in a complex large-scale architecture, with homogenic matrix production close to the surface, whereas zones further below display pronounced local heterogeneity of matrix production, which results in distinct three-dimensional architectural structures. Combining genetics, cryosectioning and fluorescence microscopy of macrocolony biofilms, we demonstrate here in situ that this local matrix heterogeneity is generated by a c-di-GMP-dependent molecular switch characterized by several nested positive and negative feedback loops. In this switch, the trigger phosphodiesterase PdeR is the key component for establishing local heterogeneity in the activation of the transcription factor MlrA, which in turn activates expression of the major matrix regulator CsgD. Upon its release of direct inhibition by PdeR, the second switch component, the diguanylate cyclase DgcM, activates MlrA by direct interaction. Antagonistically acting PdeH and DgcE provide for a PdeR-sensed c-di-GMP input into this switch and-via their spatially differentially controlled expression-generate the long-range vertical asymmetry of the matrix architecture. Using flow cytometry, we show heterogeneity of CsgD expression to also occur in spatially unstructured planktonic cultures, where it is controlled by the same c-di-GMP circuitry as in macrocolony biofilms. Quantification by flow cytometry also showed CsgDON subpopulations with distinct CsgD expression levels and revealed an additional fine-tuning feedback within the PdeR/DgcM-mediated switch that depends on c-di-GMP synthesis by DgcM. Finally, local heterogeneity of matrix production was found to be crucial for the tissue-like elasticity that allows for large-scale wrinkling and folding of macrocolony biofilms.
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Affiliation(s)
- Diego O Serra
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Regine Hengge
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany.
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39
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Paenibacillus polymyxa biofilm polysaccharides antagonise Fusarium graminearum. Sci Rep 2019; 9:662. [PMID: 30679760 PMCID: PMC6345971 DOI: 10.1038/s41598-018-37718-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/12/2018] [Indexed: 11/20/2022] Open
Abstract
Fusarium Head Blight (FHB) caused by Fusarium graminearum pathogens constitutes a major threat to agricultural production because it frequently reduces the yield and quality of the crop. The disease severity is predicted to increase in various regions owing to climate change. Integrated management where biocontrol plays an important role has been suggested in order to fight FHB. P. polymyxa A26 is known to be an effective antagonist against F. graminearum. Deeper understanding of the mode of action of P. polymyxa A26 is needed to develop strategies for its application under natural settings in order to effectively overcome the pathogenic effects. This study aims to re-evaluate a former study and reveal whether compounds other than non-ribosomal antibiotic lipopeptides could be responsible for the antagonistic effect, despite what is often reported. Wheat seedlings were grown to maturity and the spikes infected with the pathogen under greenhouse conditions. The development of FHB infection, quantified via the disease incidence severity and 100-kernel weight, was strongly correlated (r > 0.78, p < 0.01) with the content of the polysaccharide component D-glucuronic acid in the biofilm. Furthermore, while increased inoculum density from 106 to 108 cells/ml did not affect wild type performance, a significant increase was observed with the P. polymyxa mutant deficient in nonribosomal lipopeptide synthesis. Our results show that P. polymyxa A26 biofilm extracellular polysaccharides are capable of antagonizing F. graminearum and that the uronate content of the polysaccharides is of critical importance in the antagonism.
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Protein lysine acetylation plays a regulatory role in Bacillus subtilis multicellularity. PLoS One 2018; 13:e0204687. [PMID: 30265683 PMCID: PMC6161898 DOI: 10.1371/journal.pone.0204687] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 09/11/2018] [Indexed: 11/19/2022] Open
Abstract
Protein lysine acetylation is a post-translational modification that alters the charge, conformation, and stability of proteins. A number of genome-wide characterizations of lysine-acetylated proteins, or acetylomes, in bacteria have demonstrated that lysine acetylation occurs on proteins with a wide diversity of functions, including central metabolism, transcription, chemotaxis, and cell size regulation. Bacillus subtilis is a model organism for studies of sporulation, motility, cell signaling, and multicellular development (or biofilm formation). In this work, we investigated the role of global protein lysine acetylation in multicellular development in B. subtilis. We analyzed the B. subtilis acetylome under biofilm-inducing conditions and identified acetylated proteins involved in multicellularity, specifically, swarming and biofilm formation. We constructed various single and double mutants of genes known to encode enzymes involved in global protein lysine acetylation in B. subtilis. Some of those mutants showed a defect in swarming motility while others demonstrated altered biofilm phenotypes. Lastly, we picked two acetylated proteins known to be important for biofilm formation, YmcA (also known as RicA), a regulatory protein critical for biofilm induction, and GtaB, an UTP-glucose-1-phosphate uridylyltransferase that synthesizes a nucleotide sugar precursor for biosynthesis of exopolysaccharide, a key biofilm matrix component. We performed site-directed mutagenesis on the acetylated lysine codons in ymcA and gtaB, respectively, and assayed cells bearing those point mutants for biofilm formation. The mutant alleles of ymcA(K64R), gtaB(K89R), and gtaB(K191R) all demonstrated a severe biofilm defect. These results indicate the importance of acetylated lysine residues in both YmcA and GtaB. In summary, we propose that protein lysine acetylation plays a global regulatory role in B. subtilis multicellularity.
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Modeling of concentric pattern of Serratia marcescens colony. Arch Microbiol 2018; 201:87-92. [PMID: 30255199 DOI: 10.1007/s00203-018-1575-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/03/2018] [Accepted: 09/15/2018] [Indexed: 10/28/2022]
Abstract
Serratia marcescens forms different colony patterns under distinct conditions. One of them is the concentric fountain-shaped pattern with pigmented center followed by unpigmented ring and pigmented rim. In this work, we study this pattern formation by construction of the mathematical model able to display this pattern based on putative metabolical traits, supported by series of experiments and by references. A pattern formation of such colony type depends on the disposition of glucose and amino acids, and is accompanied by a pH change in the agar medium. In this paper, we confirm that a metabolic activity of growing colony alters its environment which subsequently changes the colony formation. Presented model corresponds well with the real colony behaviour.
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Thomas SA, Rodby KE, Roth EW, Wu J, Gaillard JF. Spectroscopic and Microscopic Evidence of Biomediated HgS Species Formation from Hg(II)-Cysteine Complexes: Implications for Hg(II) Bioavailability. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10030-10039. [PMID: 30078312 DOI: 10.1021/acs.est.8b01305] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We investigated the chemistry of Hg(II) during exposure of exponentially growing bacteria ( Escherichia coli, Bacillus subtilis, and Geobacter sulfurreducens) to 50 nM, 500 nM, and 5 μM total Hg(II) with and without added cysteine. With X-ray absorption spectroscopy, we provide direct evidence of the formation of cell-associated HgS for all tested bacteria. The addition of cysteine (100-1000 μM) promotes HgS formation (>70% of total cell-associated Hg(II)) as a result of the biodegradation of added cysteine to sulfide. Cell-associated HgS species are also detected when cysteine is not added as a sulfide source. Two phases of HgS, cinnabar (α-HgS) and metacinnabar (β-HgS), form depending on the total concentration of Hg(II) and sulfide in the exposure medium. However, α-HgS exclusively forms in assays that contain an excess of cysteine. Scanning transmission electron microscopy images reveal that nanoparticulate HgS(s) is primarily located at the cell surface/extracellular matrix of Gram-negative E. coli and G. sulfurreducens and in the cytoplasm/cell membrane of Gram-positive B. subtilis. Intracellular Hg(II) was detected even when the predominant cell-associated species was HgS. This study shows that HgS species can form from exogenous thiol-containing ligands and endogenous sulfide in Hg(II) biouptake assays under nondissimilatory sulfate reducing conditions, providing new considerations for the interpretation of Hg(II) biouptake results.
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Affiliation(s)
- Sara A Thomas
- Department of Civil and Environmental Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Kara E Rodby
- Department of Civil and Environmental Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Eric W Roth
- Department of Materials Science and Engineering, NU ANCE Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Jinsong Wu
- Department of Materials Science and Engineering, NU ANCE Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Jean-François Gaillard
- Department of Civil and Environmental Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
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Fuchs FM, Holland G, Moeller R, Laue M. Directed freeze-fracturing of Bacillus subtilis biofilms for conventional scanning electron microscopy. J Microbiol Methods 2018; 152:165-172. [PMID: 30125587 DOI: 10.1016/j.mimet.2018.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 10/28/2022]
Abstract
Biofilms have been intensively investigated over the past decades. Bacillus subtilis is able to form highly structured colony biofilms, and as one of the most studied Gram-positive model organisms, has helped to decipher the complex genetic regulation of biofilms. Several methods have been developed to analyze the architecture of biofilms. In this paper, we describe a method which allows the analysis of the internal structures of biofilms by scanning electron microscopy (SEM). The method uses a modified freeze-fracturing of chemically fixed biofilm to generate defined, well-preserved fractures at millimeter-scale which allows to analyze systematically the internal biofilm structure from macro- to nano-scale.
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Affiliation(s)
- Felix M Fuchs
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany.
| | - Gudrun Holland
- Robert Koch Institute, Advanced Light and Electron Microscopy (ZBS 4), Berlin, Germany
| | - Ralf Moeller
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Michael Laue
- Robert Koch Institute, Advanced Light and Electron Microscopy (ZBS 4), Berlin, Germany
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Draghi J. Links between evolutionary processes and phenotypic robustness in microbes. Semin Cell Dev Biol 2018; 88:46-53. [PMID: 29803630 DOI: 10.1016/j.semcdb.2018.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/16/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022]
Abstract
The costs and benefits of random phenotypic heterogeneity in microbes have been vigorously debated and experimental tested for decades; yet, this conversation is largely independent from discussion of phenotypic robustness in other disciplines. In this review I connect microbial examples of stochasticity with studies on the ecological and population-genetic consequences of phenotypic variability. These topics illustrate the complexity of selection pressures on phenotypic robustness and provide inspiration that this complexity can be parsed with theoretical advances and the experimental power of microbial systems.
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Affiliation(s)
- Jeremy Draghi
- Department of Biology, Brooklyn College, The Graduate Center, City University of New York, United States.
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Experimental Detection and Visualization of the Extracellular Matrix in Macrocolony Biofilms. Methods Mol Biol 2018; 1657:133-145. [PMID: 28889291 DOI: 10.1007/978-1-4939-7240-1_11] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
By adopting elaborate three-dimensional morphologies that vary according to their extracellular matrix composition, macrocolony biofilms offer a unique opportunity to interrogate about the roles of specific matrix components in shaping biofilm architecture. Here, we describe two methods optimized for Escherichia coli that profit from morphology and the high level of structural organization of macrocolonies to gain insight into the production and assembly of amyloid curli and cellulose-the two major biofilm matrix elements of E. coli-in biofilms. The first method, the macrocolony morphology assay, is based on the ability of curli and cellulose-either alone or in combination-to generate specific morphological and Congo Red-staining patterns in E. coli macrocolonies, which can then be used as a direct visual readout for the production of these matrix components. The second method involves thin sectioning of macrocolonies, which along with in situ staining of amyloid curli and cellulose and microscopic imaging allows gaining fine details of the spatial arrangement of both matrix elements inside macrocolonies. Beyond their current use with E. coli and related curli and cellulose-producing Enterobacteriaceae, both the methods offer the potential to be adapted to other bacterial species.
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Hassanov T, Karunker I, Steinberg N, Erez A, Kolodkin-Gal I. Novel antibiofilm chemotherapies target nitrogen from glutamate and glutamine. Sci Rep 2018; 8:7097. [PMID: 29740028 PMCID: PMC5940852 DOI: 10.1038/s41598-018-25401-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 04/19/2018] [Indexed: 01/06/2023] Open
Abstract
Bacteria in nature often reside in differentiated communities termed biofilms, which are an active interphase between uni-cellular and multicellular life states for bacteria. Here we demonstrate that the development of B. subtilis biofilms is dependent on the use of glutamine or glutamate as a nitrogen source. We show a differential metabolic requirement within the biofilm; while glutamine is necessary for the dividing cells at the edges, the inner cell mass utilizes lactic acid. Our results indicate that biofilm cells preserve a short-term memory of glutamate metabolism. Finally, we establish that drugs that target glutamine and glutamate utilization restrict biofilm development. Overall, our work reveals a spatial regulation of nitrogen and carbon metabolism within the biofilm, which contributes to the fitness of bacterial complex communities. This acquired metabolic division of labor within biofilm can serve as a target for novel anti-biofilm chemotherapies
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Affiliation(s)
- Tal Hassanov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Iris Karunker
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Nitai Steinberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
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Yu Y, Yan F, He Y, Qin Y, Chen Y, Chai Y, Guo JH. The ClpY-ClpQ protease regulates multicellular development in Bacillus subtilis. Microbiology (Reading) 2018; 164:848-862. [DOI: 10.1099/mic.0.000658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Yiyang Yu
- Department of Plant Pathology, Nanjing Agricultural University; Engineering Center of Bioresource Pesticide in Jiangsu Province; Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing 210095, PR China
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Fang Yan
- Department of Plant Pathology, Nanjing Agricultural University; Engineering Center of Bioresource Pesticide in Jiangsu Province; Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing 210095, PR China
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Yinghao He
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Yuxuan Qin
- Department of Biology, Northeastern University, Boston, MA 02115, USA
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China
| | - Yun Chen
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, PR China
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Jian-hua Guo
- Department of Plant Pathology, Nanjing Agricultural University; Engineering Center of Bioresource Pesticide in Jiangsu Province; Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing 210095, PR China
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Steinberg N, Rosenberg G, Keren-Paz A, Kolodkin-Gal I. Collective Vortex-Like Movement of Bacillus subtilis Facilitates the Generation of Floating Biofilms. Front Microbiol 2018; 9:590. [PMID: 29651280 PMCID: PMC5884953 DOI: 10.3389/fmicb.2018.00590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/14/2018] [Indexed: 12/29/2022] Open
Abstract
Bacteria in nature are usually found in complex multicellular structures, called biofilms. One common form of a biofilm is pellicle—a floating mat of bacteria formed in the water-air interphase. So far, our knowledge on the basic mechanisms underlying the formation of biofilms at air-liquid interfaces is not complete. In particular, the co-occurrence of motile cells and extracellular matrix producers has not been studied. In addition, the potential involvement of chemical communication in pellicle formation remained largely undefined. Our results indicate that vortex-like collective motility by aggregates of motile cells and EPS producers accelerate the formation of floating biofilms. Successful aggregation and migration to the water-air interphase depend on the chemical communication signal autoinducer 2 (AI-2). This ability of bacteria to form a biofilm in a preferable niche ahead of their potential rivals would provide a fitness advantage in the context of inter-species competition.
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Affiliation(s)
- Nitai Steinberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gili Rosenberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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ResDE Two-Component Regulatory System Mediates Oxygen Limitation-Induced Biofilm Formation by Bacillus amyloliquefaciens SQR9. Appl Environ Microbiol 2018; 84:AEM.02744-17. [PMID: 29427424 DOI: 10.1128/aem.02744-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/27/2018] [Indexed: 11/20/2022] Open
Abstract
Efficient biofilm formation and root colonization capabilities facilitate the ability of beneficial plant rhizobacteria to promote plant growth and antagonize soilborne pathogens. Biofilm formation by plant-beneficial Bacillus strains is triggered by environmental cues, including oxygen deficiency, but the pathways that sense these environmental signals and regulate biofilm formation have not been thoroughly elucidated. In this study, we showed that the ResDE two-component regulatory system in the plant growth-promoting rhizobacterium Bacillus amyloliquefaciens strain SQR9 senses the oxygen deficiency signal and regulates biofilm formation. ResE is activated by sensing the oxygen limitation-induced reduction of the NAD+/NADH pool through its PAS domain, stimulating its kinase activity, and resulting in the transfer of a phosphoryl group to ResD. The phosphorylated ResD directly binds to the promoter regions of the qoxABCD and ctaCDEF operons to improve the biosynthesis of terminal oxidases, which can interact with KinB to activate biofilm formation. These results not only revealed the novel regulatory function of the ResDE two-component system but also contributed to the understanding of the complicated regulatory network governing Bacillus biofilm formation. This research may help to enhance the root colonization and the plant-beneficial efficiency of SQR9 and other Bacillus rhizobacteria used in agriculture.IMPORTANCEBacillus spp. are widely used as bioinoculants for plant growth promotion and disease suppression. The exertion of their plant-beneficial functions is largely dependent on their root colonization, which is closely related to their biofilm formation capabilities. On the other hand, Bacillus is the model bacterium for biofilm study, and the process and molecular network of biofilm formation are well characterized (B. Mielich-Süss and D. Lopez, Environ Microbiol 17:555-565, 2015, https://doi.org/10.1111/1462-2920.12527; L. S. Cairns, L. Hobley, and N. R. Stanley-Wall, Mol Microbiol 93:587-598, 2014, https://doi.org/10.1111/mmi.12697; H. Vlamakis, C. Aguilar, R. Losick, and R. Kolter, Genes Dev 22:945-953, 2008, https://doi.org/10.1101/gad.1645008; S. S. Branda, A. Vik, L. Friedman, and R. Kolter, Trends Microbiol 13:20-26, 2005, https://doi.org/10.1016/j.tim.2004.11.006; C. Aguilar, H. Vlamakis, R. Losick, and R. Kolter, Curr Opin Microbiol 10:638-643, 2007, https://doi.org/10.1016/j.mib.2007.09.006; S. S. Branda, J. E. González-Pastor, S. Ben-Yehuda, R. Losick, and R. Kolter, Proc Natl Acad Sci U S A 98:11621-11626, 2001, https://doi.org/10.1073/pnas.191384198). However, the identification and sensing of environmental signals triggering Bacillus biofilm formation need further research. Here, we report that the oxygen deficiency signal inducing Bacillus biofilm formation is sensed by the ResDE two-component regulatory system. Our results not only revealed the novel regulatory function of the ResDE two-component regulatory system but also identified the sensing system of a biofilm-triggering signal. This knowledge can help to enhance the biofilm formation and root colonization of plant-beneficial Bacillus strains and also provide new insights of bacterial biofilm formation regulation.
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Browning LM, Lee KJ, Cherukuri PK, Huang T, Songkiatisak P, Warren S, Xu XHN. Single gold nanoparticle plasmonic spectroscopy for study of chemical-dependent efflux function of single ABC transporters of single live Bacillus subtilis cells. Analyst 2018; 143:1599-1608. [PMID: 29488517 PMCID: PMC5869163 DOI: 10.1039/c7an01787a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ATP-binding cassette (ABC) membrane transporters serve as self-defense transport apparatus in many living organisms and they can selectively extrude a wide variety of substrates, leading to multidrug resistance (MDR). The detailed molecular mechanisms remain elusive. Single nanoparticle plasmonic spectroscopy highly depends upon their sizes, shapes, chemical and surface properties. In our previous studies, we have used the size-dependent plasmonic spectra of single silver nanoparticles (Ag NPs) to study the real-time efflux kinetics of the ABC (BmrA) transporter and MexAB-OprM transporter in single live cells (Gram-positive and Gram-negative bacterium), respectively. In this study, we prepared and used purified, biocompatible and stable (non-aggregated) gold nanoparticles (Au NPs) (12.4 ± 0.9 nm) to study the efflux kinetics of single BmrA membrane transporters of single live Bacillus subtillis cells, aiming to probe chemical dependent efflux functions of BmrA transporters and their potential chemical sensing capability. Similar to those observed using Ag NPs, accumulation of the intracellular Au NPs in single live cells (WT and ΔBmrA) highly depends upon the cellular expression of BmrA and the NP concentration (0.7 and 1.4 nM). The lower accumulation of intracellular Au NPs in WT (normal expression of BmrA) than ΔBmrA (deletion of bmrA) indicates that BmrA extrudes the Au NPs out of the WT cells. The accumulation of Au NPs in the cells increases with NP concentration, suggesting that the Au NPs most likely passively diffuse into the cells, similar to antibiotics. The result demonstrates that such small Au NPs can serve as imaging probes to study the efflux function of the BmrA membrane transporter in single live cells. Furthermore, the dependence of the accumulation rate of intracellular Au NPs in single live cells upon the expression of BmrA and the concentration of the NPs is about twice higher than that of the same sized Ag NPs. This interesting finding suggests the chemical-dependent efflux kinetics of BmrA and that BmrA could distinguish nearly identical sized Au NPs from Ag NPs and might possess chemical sensing machinery.
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Affiliation(s)
- Lauren M Browning
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, USA.
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