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Involvement of Flagellin in Kin Recognition between Bacillus velezensis Strains. mSystems 2022; 7:e0077822. [PMID: 36218362 PMCID: PMC9764977 DOI: 10.1128/msystems.00778-22] [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] [Indexed: 12/25/2022] Open
Abstract
Kin discrimination in nature is an effective way for bacteria to stabilize population cooperation and maintain progeny benefits. However, so far, the research on kin discrimination for Bacillus still has concentrated on "attack and defense" between cells and diffusion-dependent molecular signals of quorum sensing, kin recognition in Bacillus, however, has not been reported. To determine whether flagellar is involve in the kin recognition of Bacillus, we constructed Bacillus velezensis SQR9 assembled with flagellin of its kin and non-kin strains, and performed a swarm boundary assay with SQR9, then analyzed sequence variation of flagellin and other flagellar structural proteins in B. velezensis genus. Our results showed that SQR9 assembled with flagellin of non-kin strains was more likely to form a border phenotype with wild-type strain SQR9 in swarm assay than that of kin strains, and that non-kin strains had greater variation in flagellin than kin strains. In B. velezensis, these variations in flagellin were prevalent and had evolved significantly faster than other flagellar structural proteins. Therefore, we proposed that flagellin is an effective tool partly involved in the kin recognition of B. velezensis strains. IMPORTANCE Kin selection plays an important role in stabilizing population cooperation and maintaining the progeny benefits for bacteria in nature. However, to date, the role of flagellin in kin recognition in Bacillus has not been reported. By using rhizospheric Bacillus velezensis SQR9, we accomplished flagellin region interchange among its related strains, and show that flagellin acts as a mediator to distinguish kin from non-kin in B. velezensis. We demonstrated the polymorphism of flagellin in B. velezensis through alignment analysis of flagellin protein sequences. Therefore, it was proposed that flagellin was likely to be an effective tool for mediating kin recognition in B. velezensis.
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102
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Morris RJ, Stevenson D, Sukhodub T, Stanley-Wall NR, MacPhee CE. Density and temperature controlled fluid extraction in a bacterial biofilm is determined by poly-γ-glutamic acid production. NPJ Biofilms Microbiomes 2022; 8:98. [PMID: 36528619 PMCID: PMC9759580 DOI: 10.1038/s41522-022-00361-5] [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: 06/04/2021] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
A hallmark of microbial biofilms is the self-production of an extracellular molecular matrix that encases the resident cells. The matrix provides protection from the environment, while spatial heterogeneity of gene expression influences the structural morphology and colony spreading dynamics. Bacillus subtilis is a model bacterial system used to uncover the regulatory pathways and key building blocks required for biofilm growth and development. In this work, we report on the emergence of a highly active population of bacteria during the early stages of biofilm formation, facilitated by the extraction of fluid from the underlying agar substrate. We trace the origin of this fluid extraction to the production of poly-γ-glutamic acid (PGA). The flagella-dependent activity develops behind a moving front of fluid that propagates from the boundary of the biofilm towards the interior. The extent of fluid proliferation is controlled by the presence of extracellular polysaccharides (EPS). We also find that PGA production is positively correlated with higher temperatures, resulting in high-temperature mature biofilm morphologies that are distinct from the rugose colony biofilm architecture typically associated with B. subtilis. Although previous reports have suggested that PGA production does not play a major role in biofilm morphology in the undomesticated isolate NCIB 3610, our results suggest that this strain produces distinct biofilm matrices in response to environmental conditions.
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Affiliation(s)
- Ryan J. Morris
- grid.4305.20000 0004 1936 7988National Biofilms Innovation Centre, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD UK
| | - David Stevenson
- grid.8241.f0000 0004 0397 2876Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH UK
| | - Tetyana Sukhodub
- grid.8241.f0000 0004 0397 2876Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH UK
| | - Nicola R. Stanley-Wall
- grid.8241.f0000 0004 0397 2876Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH UK
| | - Cait E. MacPhee
- grid.4305.20000 0004 1936 7988National Biofilms Innovation Centre, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD UK
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103
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Gong H, Jiang W, Yang Y, Zhang Y, Chen X, Li W, Yang P, Wang Z, Wang Q, Li Y. Cyclic di-GMP regulates bacterial colonization and further biocontrol efficacy of Bacillus velezensis against apple ring rot disease via its potential receptor YdaK. Front Microbiol 2022; 13:1034168. [PMID: 36590391 PMCID: PMC9800504 DOI: 10.3389/fmicb.2022.1034168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/02/2022] [Indexed: 12/23/2022] Open
Abstract
Bacillus species are among the most investigated beneficial bacteria and widely used in agricultural systems as biological control agents. Its biocontrol efficacy is controlled by diverse regulators. Cyclic diguanylate (c-di-GMP) is a nearly universal second messenger in bacteria and modulates various important physiological processes, including motility, biofilm formation, antifungal antibiotic production and host colonization. However, the impact of c-di-GMP on biocontrol efficacy of beneficial bacteria is unknown. Bacillus velezensis PG12 is an effective biocontrol strain against apple ring rot disease caused by Botryosphaeria dothidea. In this study, the contribution of c-di-GMP to biocontrol efficacy of B. velezensis PG12 was investigated. Deletion of single gene encoding diguanylate cyclase or phosphodiesterase did not affect its biocontrol efficacy against apple ring rot. However, artificial modulation of c-di-GMP level in the cells leads to a significant change of biocontrol efficacy, suggesting that c-di-GMP positively regulates biocontrol efficacy of B. velezensis PG12 against apple ring rot disease. More evidences indicate that c-di-GMP does not affect the antagonistic activity of B. velezensis PG12 against B. dothidea in vitro and in vivo, but positively regulates biofilm formation of B. velezensis PG12 and its colonization on apple fruits. Importantly, deletion of ydaK could rescue the inhibition of biofilm formation, bacterial colonization and biocontrol efficacy caused by low c-di-GMP level, indicating that YdaK is the potential c-di-GMP receptor to regulate biofilm formation, colonization and effective biological control. However, YdaK did not affect the antagonistic activity of B. velezensis PG12 against B. dothidea. Based on these findings, we propose that c-di-GMP regulates biofilm formation, subsequently the bacterial colonization on apple fruits and thus biocontrol efficacy of B. velezensis through its receptor YdaK. This is the first report showing that c-di-GMP plays a role in biocontrol efficacy of beneficial bacteria.
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Affiliation(s)
- Huiling Gong
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Wenxiao Jiang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yang Yang
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, China
| | - Yue Zhang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xufei Chen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Wei Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Panlei Yang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Zhenshuo Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Qi Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yan Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China,*Correspondence: Yan Li,
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104
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Gao GR, Hou ZJ, Ding MZ, Bai S, Wei SY, Qiao B, Xu QM, Cheng JS, Yuan YJ. Improved Production of Fengycin in Bacillus subtilis by Integrated Strain Engineering Strategy. ACS Synth Biol 2022; 11:4065-4076. [PMID: 36379006 DOI: 10.1021/acssynbio.2c00380] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fengycin is a lipopeptide with broad-spectrum antifungal activity. However, its low yield limits its commercial application. Therefore, we iteratively edited multiple target genes associated with fengycin synthesis by combinatorial metabolic engineering. The ability of Bacillus subtilis 168 to manufacture lipopeptides was restored, and the fengycin titer was 1.81 mg/L. Fengycin production was further increased to 174.63 mg/L after knocking out pathways associated with surfactin and bacillaene synthesis and replacing the native promoter (PppsA) with the Pveg promoter. Subsequently, fengycin levels were elevated to 258.52 mg/L by upregulating the expression of relevant genes involved in the fatty acid pathway. After blocking spore and biofilm formation, fengycin production reached 302.51 mg/L. Finally, fengycin production was increased to approximately 885.37 mg/L after adding threonine in the optimized culture medium, which was 488-fold higher compared with that of the initial strain. Integrated strain engineering provides a strategy to construct a system for improving fengycin production.
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Affiliation(s)
- Geng-Rong Gao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Zheng-Jie Hou
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Ming-Zhu Ding
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Song Bai
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Si-Yu Wei
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Bin Qiao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Qiu-Man Xu
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Science, Tianjin Normal University, Binshuixi Road 393, Xiqing District, Tianjin 300387, PR China
| | - Jing-Sheng Cheng
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China.,Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, PR China
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105
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A novel time-lapse imaging method for studying developing bacterial biofilms. Sci Rep 2022; 12:21120. [PMID: 36476631 PMCID: PMC9729682 DOI: 10.1038/s41598-022-24431-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
In nature, bacteria prevailingly reside in the form of biofilms. These elaborately organized surface-bound assemblages of bacterial cells show numerous features of multicellular organization. We recently showed that biofilm growth is a true developmental process, which resembles developmental processes in multicellular eukaryotes. To study the biofilm growth in a fashion of eukaryotic ontogeny, it is essential to define dynamics and critical transitional phases of this process. The first step in this endeavor is to record the gross morphological changes of biofilm ontogeny under standardized conditions. This visual information is instrumental in guiding the sampling strategy for the later omics analyses of biofilm ontogeny. However, none of the currently available visualizations methods is specifically tailored for recording gross morphology across the whole biofilm development. To address this void, here we present an affordable Arduino-based approach for time-lapse visualization of complete biofilm ontogeny using bright field stereomicroscopy with episcopic illumination. The major challenge in recording biofilm development on the air-solid interphase is water condensation, which compromises filming directly through the lid of a Petri dish. To overcome these trade-offs, we developed an Arduino microcontroller setup which synchronizes a robotic arm, responsible for opening and closing the Petri dish lid, with the activity of a stereomicroscope-mounted camera and lighting conditions. We placed this setup into a microbiological incubator that maintains temperature and humidity during the biofilm growth. As a proof-of-principle, we recorded biofilm development of five Bacillus subtilis strains that show different morphological and developmental dynamics.
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106
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Charlton SGV, Kurz DL, Geisel S, Jimenez-Martinez J, Secchi E. The role of biofilm matrix composition in controlling colony expansion and morphology. Interface Focus 2022; 12:20220035. [PMID: 36330326 PMCID: PMC9560791 DOI: 10.1098/rsfs.2022.0035] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/09/2022] [Indexed: 08/01/2023] Open
Abstract
Biofilms are biological viscoelastic gels composed of bacterial cells embedded in a self-secreted polymeric extracellular matrix (ECM). In environmental settings, such as in the rhizosphere and phyllosphere, biofilm colonization occurs at the solid-air interface. The biofilms' ability to colonize and expand over these surfaces depends on the formation of osmotic gradients and ECM viscoelastic properties. In this work, we study the influence of biofilm ECM components on its viscoelasticity and expansion, using the model organism Bacillus subtilis and deletion mutants of its three major ECM components, TasA, EPS and BslA. Using a multi-scale approach, we quantified macro-scale viscoelasticity and expansion dynamics. Furthermore, we used a microsphere assay to visualize the micro-scale expansion patterns. We find that the viscoelastic phase angle Φ is likely the best viscoelastic parameter correlating to biofilm expansion dynamics. Moreover, we quantify the sensitivity of the biofilm to changes in substrate water potential as a function of ECM composition. Finally, we find that the deletion of ECM components significantly increases the coherence of micro-scale colony expansion patterns. These results demonstrate the influence of ECM viscoelasticity and substrate water potential on the expansion of biofilm colonies on wet surfaces at the air-solid interface, commonly found in natural environments.
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Affiliation(s)
- Samuel G. V. Charlton
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
| | - Dorothee L. Kurz
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
- Department Water Resources and Drinking Water, Swiss Federal Institute of Aquatic Science and Technology, Eawag, Dübendorf, Switzerland
| | - Steffen Geisel
- Department of Materials, Soft Materials, ETH Zürich, Zürich, Switzerland
| | - Joaquin Jimenez-Martinez
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
- Department Water Resources and Drinking Water, Swiss Federal Institute of Aquatic Science and Technology, Eawag, Dübendorf, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
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107
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Geisel S, Secchi E, Vermant J. Experimental challenges in determining the rheological properties of bacterial biofilms. Interface Focus 2022; 12:20220032. [PMID: 36330324 PMCID: PMC9560794 DOI: 10.1098/rsfs.2022.0032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/03/2022] [Indexed: 08/01/2023] Open
Abstract
Bacterial biofilms are communities living in a matrix consisting of self-produced, hydrated extracellular polymeric substances. Most microorganisms adopt the biofilm lifestyle since it protects by conferring resistance to antibiotics and physico-chemical stress factors. Consequently, mechanical removal is often necessary but rendered difficult by the biofilm's complex, viscoelastic response, and adhesive properties. Overall, the mechanical behaviour of biofilms also plays a role in the spreading, dispersal and subsequent colonization of new surfaces. Therefore, the characterization of the mechanical properties of biofilms plays a crucial role in controlling and combating biofilms in industrial and medical environments. We performed in situ shear rheological measurements of Bacillus subtilis biofilms grown between the plates of a rotational rheometer under well-controlled conditions relevant to many biofilm habitats. We investigated how the mechanical history preceding rheological measurements influenced biofilm mechanics and compared these results to the techniques commonly used in the literature. We also compare our results to measurements using interfacial rheology on bacterial pellicles formed at the air-water interface. This work aims to help understand how different growth and measurement conditions contribute to the large variability of mechanical properties reported in the literature and provide a new tool for the rigorous characterization of matrix components and biofilms.
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Affiliation(s)
- Steffen Geisel
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Jan Vermant
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
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108
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Li B, Duan J, Ren J, Francis F, Li G. Isolation and Characterization of Two New Deoxynivalenol-Degrading Strains, Bacillus sp. HN117 and Bacillus sp. N22. Toxins (Basel) 2022; 14:toxins14110781. [PMID: 36356030 PMCID: PMC9693629 DOI: 10.3390/toxins14110781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Deoxynivalenol (DON), produced by Fusarium species, is one of the most common trichothecenes detected in cereals pre- and post-harvest, which poses a great threat to the health of livestock and human beings due to its strong toxicity. In this study, we isolated and characterized two DON-degrading bacterial strains, Bacillus sp. HN117 and Bacillus sp. N22. Both strains could degrade DON efficiently in a wide range of temperatures (from 25 °C to 42 °C) and concentrations (from 10 mg/L to 500 mg/L). After optimization of the degradation conditions, 29.0% DON was eliminated by HN117 in 72 h when it was incubated with 1000 mg/L DON; meanwhile, the DON degradation rate of N22 was boosted notably from 7.41% to 21.21% within 120 h at 500 mg/L DON. Degradation products analysis indicated HN117 was able to transform DON into a new isomer M-DOM, the possible structure of which was deduced based on LC-MS and NMR analysis, and N22 could convert DON into potential low-toxic derivatives norDON E and 9-hydroxymethyl DON lactone. These two strains have the potential to be developed as new biodegrading agents to control DON contamination in food and feed industries.
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Affiliation(s)
- Beibei Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests—Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium
| | - Jiaqi Duan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests—Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jie Ren
- State Key Laboratory for Biology of Plant Diseases and Insect Pests—Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Frédéric Francis
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liège, B-5030 Gembloux, Belgium
- Correspondence: (F.F.); (G.L.)
| | - Guangyue Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests—Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-Product Quality and Safety, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Correspondence: (F.F.); (G.L.)
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109
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A deep neural networks framework for in-situ biofilm thickness detection and hydrodynamics tracing for filtration systems. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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110
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Santos FM, Viera LS, Camargo DP, Muniz MF, Costa IF, Guedes JV, Santos JR, Silva JC. Integrating a Bacillus-based product with fungicides by foliar application to protect soybean: a sustainable approach to avoid exclusive use of chemicals. PEST MANAGEMENT SCIENCE 2022; 78:4832-4840. [PMID: 35908173 DOI: 10.1002/ps.7104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 06/05/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Biological control is widely applied against soybean (Glycine max L.) soil-borne pathogens by furrow or seed treatments. The efficiency of bioproducts and timing of application by foliar sprays against soybean pathogens needs to be more fully understood. This work investigated the efficiency of foliar application with a Bacillus subtilis-based product (BBP) to protect soybean from multiple pathogens and the best moment to apply it considering its compatibility with fungicides. RESULTS Foliar applications (from stages V6 to R4) with BBP, mancozeb (M) and systemic fungicides (S) applied against Asian rust (Phakopsora pachyrhizi), BBP followed by S (BBP-S), BBP along with S (S + BBP), S along with M (S + M) or water were carried out in a soybean field for two years. The treatments S + BBP, S + M and BBP-S reduced the severity of Asian rust by 82% compared to the control. Except for M, all treatments reduced the severity of other foliar diseases by >60%. The defoliation was reduced by BBP and BBP-S, whereas the yield was 25% higher than control by using BBP, S + M, S + BBP or BBP-S. Also, the incidence of Fusarium sp. was significantly reduced on seeds from treatments BBP and BBP-S. The compatibility tests in Petri dishes demonstrated that all fungicides decreased the bacterial growth when applied along with BBP, whereas previous applications of BBP did not reduce the bacterial growth. CONCLUSIONS The BBP protected soybean against multiple pathogens, reduced defoliation and promoted soybean yield similarly to conventional fungicides, but in general, the early application of the BBP was the most efficient protection. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Fabio M Santos
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Laura S Viera
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Darcila P Camargo
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Marlove Fb Muniz
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Ivan Fd Costa
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Jerson Vc Guedes
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Jansen Rp Santos
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
| | - Julio Cp Silva
- Department of Phytosanitary Defense, CCR, Federal University of Santa Maria, (UFSM), Santa Maria, Brazil
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111
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Bertê R, Teixeira GM, de Oliveira JP, Nicoletto MLA, da Silva DV, de Godoy GG, Sanches DS, de Resende JTV, Pereira UDP, Nunes da Rocha U, de Oliveira AG. Genome Mining Reveals High Biosynthetic Potential of Biocontrol Agent Bacillus velezensis B.BV10. Genes (Basel) 2022; 13:1984. [PMID: 36360221 PMCID: PMC9690179 DOI: 10.3390/genes13111984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/18/2022] [Accepted: 10/27/2022] [Indexed: 01/07/2024] Open
Abstract
The present study demonstrates the biocontrol potential of a plant growth-promoting bacterial strain using three different approaches: (i) an in vitro evaluation of antagonistic activity against important phytopathogenic fungi; (ii) an evaluation under greenhouse conditions with strawberry plants to assess the control of gray mold; and (iii) an in silico whole genome sequence mining to assign genetic features such as gene clusters or isolated genes to the strain activity. The in vitro assay showed that the B.BV10 strain presented antagonistic activity, inhibiting the mycelial growth in all the phytopathogenic fungi evaluated. The application of the Bacillus velezensis strain B.BV10 under greenhouse conditions reduced the presence of Botrytis cinerea and increased the mean fruit biomass. The genome of B.BV10 was estimated at 3,917,533 bp, with a GC content of 46.6% and 4088 coding DNA sequences, and was identified as B. velezensis. Biosynthetic gene clusters related to the synthesis of the molecules with antifungal activity were found in its genome. Genes related to the regulation/formation of biofilms, motility, and the important properties for the rhizospheric colonization were also found in the genome. The current study offers a comprehensive understanding of the genomic architecture and control activity of phytopathogenic fungi by the B. velezensis strain B.BV10 that may substantiate the industrialization of this strain in the future.
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Affiliation(s)
- Rosiana Bertê
- Department of Microbiology, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
| | - Gustavo Manoel Teixeira
- Department of Microbiology, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
| | - João Paulo de Oliveira
- Department of Microbiology, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
| | | | - Daniel Vieira da Silva
- Department of Microbiology, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
| | | | - Danilo Sipoli Sanches
- Computer Science Department, Universidade Tecnológica Federal do Paraná, Cornélio Procópio 86300000, PR, Brazil
| | | | - Ulisses de Padua Pereira
- Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
| | - Ulisses Nunes da Rocha
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research–UFZ GmbH, 04318 Leipzig, Germany
| | - Admilton Gonçalves de Oliveira
- Department of Microbiology, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
- Laboratory of Electron Microscopy and Microanalysis, Universidade Estadual de Londrina, Londrina 86057-970, PR, Brazil
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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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113
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Allard P, Papazotos F, Potvin-Trottier L. Microfluidics for long-term single-cell time-lapse microscopy: Advances and applications. Front Bioeng Biotechnol 2022; 10:968342. [PMID: 36312536 PMCID: PMC9597311 DOI: 10.3389/fbioe.2022.968342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Cells are inherently dynamic, whether they are responding to environmental conditions or simply at equilibrium, with biomolecules constantly being made and destroyed. Due to their small volumes, the chemical reactions inside cells are stochastic, such that genetically identical cells display heterogeneous behaviors and gene expression profiles. Studying these dynamic processes is challenging, but the development of microfluidic methods enabling the tracking of individual prokaryotic cells with microscopy over long time periods under controlled growth conditions has led to many discoveries. This review focuses on the recent developments of one such microfluidic device nicknamed the mother machine. We overview the original device design, experimental setup, and challenges associated with this platform. We then describe recent methods for analyzing experiments using automated image segmentation and tracking. We further discuss modifications to the experimental setup that allow for time-varying environmental control, replicating batch culture conditions, cell screening based on their dynamic behaviors, and to accommodate a variety of microbial species. Finally, this review highlights the discoveries enabled by this technology in diverse fields, such as cell-size control, genetic mutations, cellular aging, and synthetic biology.
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Affiliation(s)
- Paige Allard
- Department of Biology, Concordia University, Montréal, QC, Canada
| | - Fotini Papazotos
- Department of Biology, Concordia University, Montréal, QC, Canada
| | - Laurent Potvin-Trottier
- Department of Biology, Concordia University, Montréal, QC, Canada
- Department of Physics, Concordia University, Montréal, QC, Canada
- Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, Canada
- *Correspondence: Laurent Potvin-Trottier,
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114
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Jautzus T, van Gestel J, Kovács ÁT. Complex extracellular biology drives surface competition during colony expansion in Bacillus subtilis. THE ISME JOURNAL 2022; 16:2320-2328. [PMID: 35790818 PMCID: PMC9477810 DOI: 10.1038/s41396-022-01279-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/13/2022] [Accepted: 06/20/2022] [Indexed: 04/29/2023]
Abstract
Many bacteria grow on surfaces in nature, where they form cell collectives that compete for space. Within these collectives, cells often secrete molecules that benefit surface spreading by, for example, reducing surface tension or promoting filamentous growth. Although we have a detailed understanding of how these molecules are produced, much remains unknown about their role in surface competition. Here we examine sliding motility in Bacillus subtilis and compare how secreted molecules, essential for sliding, affect intraspecific cooperation and competition on a surface. We specifically examine (i) the lipopeptide surfactin, (ii) the hydrophobin protein BslA, and (iii) exopolysaccharides (EPS). We find that these molecules have a distinct effect on surface competition. Whereas surfactin acts like a common good, which is costly to produce and benefits cells throughout the surface, BslA and EPS are cost-free and act locally. Accordingly, surfactin deficient mutants can exploit the wild-type strain in competition for space, while BslA and EPS mutants cannot. Supported by a mathematical model, we show that three factors are important in predicting the outcome of surface competition: the costs of molecule synthesis, the private benefits of molecule production, and the diffusion rate. Our results underscore the intricate extracellular biology that can drive bacterial surface competition.
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Affiliation(s)
- Theresa Jautzus
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Jordi van Gestel
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Ákos T Kovács
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, 07743, Jena, Germany.
- Bacterial Interactions and Evolution Group, Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark.
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115
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Sun C, Wang X, Dai J, Ju Y. Metal and Metal Oxide Nanomaterials for Fighting Planktonic Bacteria and Biofilms: A Review Emphasizing on Mechanistic Aspects. Int J Mol Sci 2022; 23:ijms231911348. [PMID: 36232647 PMCID: PMC9569886 DOI: 10.3390/ijms231911348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/16/2022] Open
Abstract
The misuse and mismanagement of antibiotics have made the treatment of bacterial infections a challenge. This challenge is magnified when bacteria form biofilms, which can increase bacterial resistance up to 1000 times. It is desirable to develop anti-infective materials with antibacterial activity and no resistance to drugs. With the rapid development of nanotechnology, anti-infective strategies based on metal and metal oxide nanomaterials have been widely used in antibacterial and antibiofilm treatments. Here, this review expounds on the state-of-the-art applications of metal and metal oxide nanomaterials in bacterial infective diseases. A specific attention is given to the antibacterial mechanisms of metal and metal oxide nanomaterials, including disrupting cell membranes, damaging proteins, and nucleic acid. Moreover, a practical antibiofilm mechanism employing these metal and metal oxide nanomaterials is also introduced based on the composition of biofilm, including extracellular polymeric substance, quorum sensing, and bacteria. Finally, current challenges and future perspectives of metal and metal oxide nanomaterials in the anti-infective field are presented to facilitate their development and use.
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Affiliation(s)
- Caixia Sun
- College of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Xiaobai Wang
- Department of Materials Application Research, AVIC Manufacturing Technology Institute, Beijing 100024, China
| | - Jianjun Dai
- College of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
- College of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, China
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 211198, China
- State Key Laboratory of Natural Medicine, China Pharmaceutical University, Nanjing 211198, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- Laboratory of Animal Bacteriology (Ministry of Agriculture), College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanmin Ju
- College of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
- Correspondence:
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Imai T, Tobe R, Honda K, Tanaka M, Kawamoto J, Mihara H. Group II truncated haemoglobin YjbI prevents reactive oxygen species-induced protein aggregation in Bacillus subtilis. eLife 2022; 11:70467. [PMID: 36125244 PMCID: PMC9536834 DOI: 10.7554/elife.70467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/19/2022] [Indexed: 12/12/2022] Open
Abstract
Oxidative stress-mediated formation of protein hydroperoxides can induce irreversible fragmentation of the peptide backbone and accumulation of cross-linked protein aggregates, leading to cellular toxicity, dysfunction, and death. However, how bacteria protect themselves from damages caused by protein hydroperoxidation is unknown. Here, we show that YjbI, a group II truncated haemoglobin from Bacillus subtilis, prevents oxidative aggregation of cell-surface proteins by its protein hydroperoxide peroxidase-like activity, which removes hydroperoxide groups from oxidised proteins. Disruption of the yjbI gene in B. subtilis lowered biofilm water repellence, which associated with the cross-linked aggregation of the biofilm matrix protein TasA. YjbI was localised to the cell surface or the biofilm matrix, and the sensitivity of planktonically grown cells to generators of reactive oxygen species was significantly increased upon yjbI disruption, suggesting that YjbI pleiotropically protects labile cell-surface proteins from oxidative damage. YjbI removed hydroperoxide residues from the model oxidised protein substrate bovine serum albumin and biofilm component TasA, preventing oxidative aggregation in vitro. Furthermore, the replacement of Tyr63 near the haem of YjbI with phenylalanine resulted in the loss of its protein peroxidase-like activity, and the mutant gene failed to rescue biofilm water repellency and resistance to oxidative stress induced by hypochlorous acid in the yjbI-deficient strain. These findings provide new insights into the role of truncated haemoglobin and the importance of hydroperoxide removal from proteins in the survival of aerobic bacteria.
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Affiliation(s)
- Takeshi Imai
- Hyogo Prefectural Institute of Technology, Hyogo, Japan
| | - Ryuta Tobe
- Department of Biotechnology, Ritsumeikan University, Shiga, Japan
| | - Koji Honda
- Hyogo Prefectural Institute of Technology, Hyogo, Japan
| | - Mai Tanaka
- Department of Biotechnology, Ritsumeikan University, Shiga, Japan
| | - Jun Kawamoto
- Institute for Chemical Research, Kyoto University, Kyoto, Japan
| | - Hisaaki Mihara
- Department of Biotechnology, Ritsumeikan University, Shiga, Japan
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117
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Liu J, Zhou X, Wang T, Fan L, Liu S, Wu N, Xu A, Qian X, Li Z, Jiang M, Zhou J, Dong W. Construction and comparison of synthetic microbial consortium system (SMCs) by non-living or living materials immobilization and application in acetochlor degradation. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129460. [PMID: 35803189 DOI: 10.1016/j.jhazmat.2022.129460] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The microbial degradation of pesticides by pure or mixed microbial cultures has been thoroughly explored, however, they are still difficult to apply in real environmental remediation. Here, we constructed a synthetic microbial consortium system (SMCs) through the immobilization technology by non-living or living materials to improve the acetochlor degradation efficiency. Rhodococcus sp. T3-1, Delftia sp. T3-6 and Sphingobium sp. MEA3-1 were isolated for the SMCs construction. The free-floating consortium with the composition ratio of 1:2:2 (Rhodococcus sp. T3-1, Delftia sp. T3-6 and Sphingobium sp. MEA3-1) demonstrated 94.8% degradation of acetochlor, and the accumulation of intermediate metabolite 2-methyl-6-ethylaniline was decreased by 3 times. The immobilized consortium using composite materials showed synergistic effects on the acetochlor degradation with maximum degradation efficiency of 97.81%. In addition, a novel immobilization method with the biofilm of Myxococcus xanthus DK1622 as living materials was proposed. The maximum 96.62% degradation was obtained in non-trophic media. Furthermore, the immobilized SMCs showed significantly enhanced environmental robustness, reusability and stability. The results indicate the promising application of the immobilization methods using composite and living materials in pollutant-contaminated environments.
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Affiliation(s)
- Jingyuan Liu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Xiaoli Zhou
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Tong Wang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Lingling Fan
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Shixun Liu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Nan Wu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Anming Xu
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Xiujuan Qian
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Zhoukun Li
- Key Laboratory of Agriculture Environmental Microbiology, College of Life Science, Nanjing Agriculture University, Nanjing 210095, PR China
| | - Min Jiang
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Jie Zhou
- Key Laboratory for Waste Plastics Biocatalytic Degradation and Recycling, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China.
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, PR China.
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118
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Wang Y, Bian Z, Wang Y. Biofilm formation and inhibition mediated by bacterial quorum sensing. Appl Microbiol Biotechnol 2022; 106:6365-6381. [DOI: 10.1007/s00253-022-12150-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/25/2022]
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119
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Nie LJ, Ye WQ, Xie WY, Zhou WW. Biofilm: New insights in the biological control of fruits with Bacillus amyloliquefaciens B4. Microbiol Res 2022; 265:127196. [PMID: 36116146 DOI: 10.1016/j.micres.2022.127196] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 08/07/2022] [Accepted: 09/09/2022] [Indexed: 10/14/2022]
Abstract
Biofilms are sessile microbial communities growing on surfaces, which are encased in some self-produced extracellular material. Beneficial biofilm could be widely used in agriculture, food, medicine, environment and other fields. As an ideal biocontrol agent, Bacillus amyloliquefaciens B4 can form a strong biofilm under static conditions. In this study, we screened out metal compounds that enhanced or inhibited the biofilm formation ability of B4, established the relationship between the biofilm of B4 strain and its postharvest biocontrol effect, and explored the regulation of metal compounds on the biofilm formation. The results showed 0.5 mmol L-1 ferric chloride could enhance the biofilm formation and strengthen the antifungal effect of B4, indicating that there was a positive relationship between the growth of biofilm and its biocontrol effect. The enhanced biofilm had a certain biocontrol effect on different fruit, including peach, loquat, Kyoho grape and cherry tomato. Furthermore, the expression of degU and tasA was affected by metal ion treatment, which meant the genes might be essential for the biofilm formation of B4. Our findings suggested that biofilm of B. amyloliquefaciens played an essential role in the process of biocontrol and it might be a novel strategy for managing postharvest fruit decay.
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Affiliation(s)
- Lin-Jie Nie
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Wan-Qiong Ye
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Wan-Yue Xie
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Wen-Wen Zhou
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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120
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Wu X, Fan Y, Wang R, Zhao Q, Ali Q, Wu H, Gu Q, Borriss R, Xie Y, Gao X. Bacillus halotolerans KKD1 induces physiological, metabolic and molecular reprogramming in wheat under saline condition. FRONTIERS IN PLANT SCIENCE 2022; 13:978066. [PMID: 36035675 PMCID: PMC9404337 DOI: 10.3389/fpls.2022.978066] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Salt stress decreases plant growth and is a major threat to crop yields worldwide. The present study aimed to alleviate salt stress in plants by inoculation with halophilic plant growth-promoting rhizobacteria (PGPR) isolated from an extreme environment in the Qinghai-Tibetan Plateau. Wheat plants inoculated with Bacillus halotolerans KKD1 showed increased seedling morphological parameters and physiological indexes. The expression of wheat genes directly involved in plant growth was upregulated in the presence of KKD1, as shown by real-time quantitative PCR (RT-qPCR) analysis. The metabolism of phytohormones, such as 6-benzylaminopurine and gibberellic acid were also enhanced. Mining of the KKD1 genome corroborated its potential plant growth promotion (PGP) and biocontrol properties. Moreover, KKD1 was able to support plant growth under salt stress by inducing a stress response in wheat by modulating phytohormone levels, regulating lipid peroxidation, accumulating betaine, and excluding Na+. In addition, KKD1 positively affected the soil nitrogen content, soil phosphorus content and soil pH. Our findings indicated that KKD1 is a promising candidate for encouraging wheat plant growth under saline conditions.
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Affiliation(s)
- Xiaohui Wu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State Key Laboratory of Plateau Ecology and Agriculture, Department of Grassland Science, College of Agricultural and Husbandry, Qinghai University, Xining, China
| | - Yaning Fan
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ruoyi Wang
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qian Zhao
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qurban Ali
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Huijun Wu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qin Gu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Rainer Borriss
- Institut für Biologie, Humboldt Universität, Berlin, Germany
- Nord Reet UG, Greifswald, Germany
| | - Yongli Xie
- State Key Laboratory of Plateau Ecology and Agriculture, Department of Grassland Science, College of Agricultural and Husbandry, Qinghai University, Xining, China
| | - Xuewen Gao
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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121
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Zhu L, Huang J, Lu X, Zhou C. Development of plant systemic resistance by beneficial rhizobacteria: Recognition, initiation, elicitation and regulation. FRONTIERS IN PLANT SCIENCE 2022; 13:952397. [PMID: 36017257 PMCID: PMC9396261 DOI: 10.3389/fpls.2022.952397] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
A plant growing in nature is not an individual, but it holds an intricate community of plants and microbes with relatively stable partnerships. The microbial community has recently been demonstrated to be closely linked with plants since their earliest evolution, to help early land plants adapt to environmental threats. Mounting evidence has indicated that plants can release diverse kinds of signal molecules to attract beneficial bacteria for mediating the activities of their genetics and biochemistry. Several rhizobacterial strains can promote plant growth and enhance the ability of plants to withstand pathogenic attacks causing various diseases and loss in crop productivity. Beneficial rhizobacteria are generally called as plant growth-promoting rhizobacteria (PGPR) that induce systemic resistance (ISR) against pathogen infection. These ISR-eliciting microbes can mediate the morphological, physiological and molecular responses of plants. In the last decade, the mechanisms of microbial signals, plant receptors, and hormone signaling pathways involved in the process of PGPR-induced ISR in plants have been well investigated. In this review, plant recognition, microbial elicitors, and the related pathways during plant-microbe interactions are discussed, with highlights on the roles of root hair-specific syntaxins and small RNAs in the regulation of the PGPR-induced ISR in plants.
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Affiliation(s)
- Lin Zhu
- Key Lab of Bio-Organic Fertilizer Creation, Ministry of Agriculture and Rural Affairs, Anhui Science and Technology University, Bengbu, China
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jiameng Huang
- Key Lab of Bio-Organic Fertilizer Creation, Ministry of Agriculture and Rural Affairs, Anhui Science and Technology University, Bengbu, China
| | - Xiaoming Lu
- Key Lab of Bio-Organic Fertilizer Creation, Ministry of Agriculture and Rural Affairs, Anhui Science and Technology University, Bengbu, China
| | - Cheng Zhou
- Key Lab of Bio-Organic Fertilizer Creation, Ministry of Agriculture and Rural Affairs, Anhui Science and Technology University, Bengbu, China
- Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Nanjing Agricultural University, Nanjing, China
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122
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Jakab Á, Kovács F, Balla N, Tóth Z, Ragyák Á, Sajtos Z, Csillag K, Nagy-Köteles C, Nemes D, Bácskay I, Pócsi I, Majoros L, Kovács ÁT, Kovács R. Physiological and transcriptional profiling of surfactin exerted antifungal effect against Candida albicans. Biomed Pharmacother 2022; 152:113220. [PMID: 35671583 DOI: 10.1016/j.biopha.2022.113220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/19/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022] Open
Abstract
Given the risk of Candida albicans overgrowth in the gut, novel complementary therapies should be developed to reduce fungal dominancy. This study highlights the antifungal characteristics of a Bacillus subtilis-derived secondary metabolite, surfactin with high potential against C. albicans. Surfactin inhibited the growth of C. albicans following a 1-hour exposure, in addition to reduced adhesion and morphogenesis. Specifically, surfactin did not affect the level of reactive oxygen species but increased the level of reduced glutathione. Surprisingly, ethanol production was increased following 2 h of surfactin exposure. Surfactin treatment caused a significant reduction in intracellular iron, manganese and zinc content compared to control cells, whereas the level of copper was not affected. Alongside these physiological properties, surfactin also enhanced fluconazole efficacy. To gain detailed insights into the surfactin-related effects on C. albicans, genome-wide gene transcription analysis was performed. Surfactin treatment resulted in 1390 differentially expressed genes according to total transcriptome sequencing (RNA-Seq). Of these, 773 and 617 genes with at least a 1.5-fold increase or decrease in transcription, respectively, were selected for detailed investigation. Several genes involved in morphogenesis or related to metabolism (e.g., glycolysis, ethanol and fatty acid biosynthesis) were down-regulated. Moreover, surfactin decreased the expression of ERG1, ERG3, ERG9, ERG10 and ERG11 involved in ergosterol synthesis, whereas genes associated with ribosome biogenesis and iron metabolism and drug transport-related genes were up-regulated. Our data demonstrate that surfactin significantly influences the physiology and gene transcription of C. albicans, and could contribute to the development of a novel innovative complementary therapy.
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Affiliation(s)
- Ágnes Jakab
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary; Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Fruzsina Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, Hungary
| | - Noémi Balla
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, Hungary
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, Hungary
| | - Ágota Ragyák
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary; Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Zsófi Sajtos
- Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Kinga Csillag
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Csaba Nagy-Köteles
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Dániel Nemes
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Ildikó Bácskay
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary.
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Porter M, Davidson FA, MacPhee CE, Stanley-Wall NR. Systematic microscopical analysis reveals obligate synergy between extracellular matrix components during Bacillus subtilis colony biofilm development. Biofilm 2022; 4:100082. [PMID: 36148433 PMCID: PMC9486643 DOI: 10.1016/j.bioflm.2022.100082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/11/2022] [Accepted: 08/11/2022] [Indexed: 12/03/2022] Open
Abstract
Single-species bacterial colony biofilms often present recurring morphologies that are thought to be of benefit to the population of cells within and are known to be dependent on the self-produced extracellular matrix. However, much remains unknown in terms of the developmental process at the single cell level. Here, we design and implement systematic time-lapse imaging and quantitative analyses of the growth of Bacillus subtilis colony biofilms. We follow the development from the initial deposition of founding cells through to the formation of large-scale complex structures. Using the model biofilm strain NCIB 3610, we examine the movement dynamics of the growing biomass and compare them with those displayed by a suite of otherwise isogenic matrix-mutant strains. Correspondingly, we assess the impact of an incomplete matrix on biofilm morphologies and sessile growth rate. Our results indicate that radial expansion of colony biofilms results from the division of bacteria at the biofilm periphery rather than being driven by swelling due to fluid intake. Moreover, we show that lack of exopolysaccharide production has a negative impact on cell division rate, and the extracellular matrix components act synergistically to give the biomass the structural strength to produce aerial protrusions and agar substrate-deforming ability.
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Chahar M, Gollop R, Kroupitski Y, Shemesh M, Sela Saldinger S. Control of Salmonella in mung bean sprouts by antagonistic spore-forming bacilli. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.109276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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125
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Shi Y, Chen T, Shaw P, Wang PY. Manipulating Bacterial Biofilms Using Materiobiology and Synthetic Biology Approaches. Front Microbiol 2022; 13:844997. [PMID: 35875573 PMCID: PMC9301480 DOI: 10.3389/fmicb.2022.844997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 06/13/2022] [Indexed: 11/25/2022] Open
Abstract
Bacteria form biofilms on material surfaces within hours. Biofilms are often considered problematic substances in the fields such as biomedical devices and the food industry; however, they are beneficial in other fields such as fermentation, water remediation, and civil engineering. Biofilm properties depend on their genome and the extracellular environment, including pH, shear stress, and matrices topography, stiffness, wettability, and charges during biofilm formation. These surface properties have feedback effects on biofilm formation at different stages. Due to emerging technology such as synthetic biology and genome editing, many studies have focused on functionalizing biofilm for specific applications. Nevertheless, few studies combine these two approaches to produce or modify biofilms. This review summarizes up-to-date materials science and synthetic biology approaches to controlling biofilms. The review proposed a potential research direction in the future that can gain better control of bacteria and biofilms.
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Affiliation(s)
- Yue Shi
- Oujiang Laboratory, Key Laboratory of Alzheimer’s Disease of Zhejiang Province, Institute of Aging, Wenzhou Medical University, Wenzhou, China
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Tingli Chen
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Peter Shaw
- Oujiang Laboratory, Key Laboratory of Alzheimer’s Disease of Zhejiang Province, Institute of Aging, Wenzhou Medical University, Wenzhou, China
| | - Peng-Yuan Wang
- Oujiang Laboratory, Key Laboratory of Alzheimer’s Disease of Zhejiang Province, Institute of Aging, Wenzhou Medical University, Wenzhou, China
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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126
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Bacillus subtilis biofilm matrix components target seed oil bodies to promote growth and anti-fungal resistance in melon. Nat Microbiol 2022; 7:1001-1015. [PMID: 35668112 PMCID: PMC9246715 DOI: 10.1038/s41564-022-01134-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 04/25/2022] [Indexed: 12/13/2022]
Abstract
Beneficial microorganisms are used to stimulate the germination of seeds; however, their growth-promoting mechanisms remain largely unexplored. Bacillus subtilis is commonly found in association with different plant organs, providing protection against pathogens or stimulating plant growth. We report that application of B. subtilis to melon seeds results in genetic and physiological responses in seeds that alter the metabolic and developmental status in 5-d and 1-month-old plants upon germination. We analysed mutants in different components of the extracellular matrix of B. subtilis biofilms in interaction with seeds and found cooperation in bacterial colonization of seed storage tissues and growth promotion. Combining confocal microscopy with fluorogenic probes, we found that two specific components of the extracellular matrix, amyloid protein TasA and fengycin, differentially increased the concentrations of reactive oxygen species inside seeds. Further, using electron and fluorescence microscopy and metabolomics, we showed that both TasA and fengycin targeted the oil bodies in the seed endosperm, resulting in specific changes in lipid metabolism and accumulation of glutathione-related molecules. In turn, this results in two different plant growth developmental programmes: TasA and fengycin stimulate the development of radicles, and fengycin alone stimulate the growth of adult plants and resistance in the phylloplane to the fungus Botrytis cinerea. Understanding mechanisms of bacterial growth promotion will enable the design of bespoke growth promotion strains. Mechanisms of growth promotion of Bacillus subtilis on melon seeds are identified using a combination of multi-omics and microscopy.
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127
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Liu X, Inda ME, Lai Y, Lu TK, Zhao X. Engineered Living Hydrogels. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201326. [PMID: 35243704 PMCID: PMC9250645 DOI: 10.1002/adma.202201326] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/01/2022] [Indexed: 05/31/2023]
Abstract
Living biological systems, ranging from single cells to whole organisms, can sense, process information, and actuate in response to changing environmental conditions. Inspired by living biological systems, engineered living cells and nonliving matrices are brought together, which gives rise to the technology of engineered living materials. By designing the functionalities of living cells and the structures of nonliving matrices, engineered living materials can be created to detect variability in the surrounding environment and to adjust their functions accordingly, thereby enabling applications in health monitoring, disease treatment, and environmental remediation. Hydrogels, a class of soft, wet, and biocompatible materials, have been widely used as matrices for engineered living cells, leading to the nascent field of engineered living hydrogels. Here, the interactions between hydrogel matrices and engineered living cells are described, focusing on how hydrogels influence cell behaviors and how cells affect hydrogel properties. The interactions between engineered living hydrogels and their environments, and how these interactions enable versatile applications, are also discussed. Finally, current challenges facing the field of engineered living hydrogels for their applications in clinical and environmental settings are highlighted.
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Affiliation(s)
- Xinyue Liu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Maria Eugenia Inda
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Yong Lai
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Timothy K Lu
- Synthetic Biology Group, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Xuanhe Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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128
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Xu S, Cao Q, Liu Z, Chen J, Yan P, Li B, Xu Y. Transcriptomic Analysis Reveals the Role of tmRNA on Biofilm Formation in Bacillus subtilis. Microorganisms 2022; 10:microorganisms10071338. [PMID: 35889057 PMCID: PMC9319509 DOI: 10.3390/microorganisms10071338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 11/16/2022] Open
Abstract
Bacillus strains are widely distributed in terrestrial and marine environments, and some of them are used as biocontrol organisms for their biofilm-formation ability. In Bacillus subtilis, biofilm formation is fine-tuned by a complex network, a clear understanding of which still requires study. In bacteria, tmRNA, encoded by the ssrA gene, catalyzes trans-translation that can rescue ribosomes stalled on mRNA transcripts lacking a functional stop codon. tmRNA also affects physiological bioprocesses in some bacteria. In this study, we constructed a ssrA mutant in B. subtilis and found that the biofilm formation in the ssrA mutant was largely impaired. Moreover, we isolated a biofilm-formation suppressor of ssrA, in which the biofilm formation was restored to a level even stronger than that in the wild type. We further performed RNAseq assays with the wild type, ssrA mutant, and suppressor of ssrA for comparisons of their transcriptomes. By analyzing the transcriptomic data, we predicted the possible functions of some differentially expressed genes (DEGs) in the tmRNA regulation of biofilm formation in B. subtilis. Finally, we found that the overexpression of two DEGs, acoA and yhjR, could restore the biofilm formation in the ssrA mutant, indicating that AcoA and YhjR were immediate regulators involved in the tmRNA regulatory web controlling biofilm formation in B. subtilis. Our data can improve the knowledge about the molecular network involved in Bacillus biofilm formation and provide new targets for manipulation of Bacillus biofilms for future investigation.
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Affiliation(s)
- Shanshan Xu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Qianqian Cao
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
| | - Zengzhi Liu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Junpeng Chen
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
| | - Peiguang Yan
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Bingyu Li
- Guangdong Key Laboratory for Genome Stability and Disease Prevention, Health Science Center, Shenzhen University, Shenzhen 518055, China
- Correspondence: (B.L.); (Y.X.)
| | - Ying Xu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518055, China; (S.X.); (Q.C.); (Z.L.); (J.C.)
- Correspondence: (B.L.); (Y.X.)
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129
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Archaeal bundling pili of Pyrobaculum calidifontis reveal similarities between archaeal and bacterial biofilms. Proc Natl Acad Sci U S A 2022; 119:e2207037119. [PMID: 35727984 DOI: 10.1073/pnas.2207037119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While biofilms formed by bacteria have received great attention due to their importance in pathogenesis, much less research has been focused on the biofilms formed by archaea. It has been known that extracellular filaments in archaea, such as type IV pili, hami, and cannulae, play a part in the formation of archaeal biofilms. We have used cryo-electron microscopy to determine the atomic structure of a previously uncharacterized class of archaeal surface filaments from hyperthermophilic Pyrobaculum calidifontis. These filaments, which we call archaeal bundling pili (ABP), assemble into highly ordered bipolar bundles. The bipolar nature of these bundles most likely arises from the association of filaments from at least two different cells. The component protein, AbpA, shows homology, both at the sequence and structural level, to the bacterial protein TasA, a major component of the extracellular matrix in bacterial biofilms, contributing to biofilm stability. We show that AbpA forms very stable filaments in a manner similar to the donor-strand exchange of bacterial TasA fibers and chaperone-usher pathway pili where a β-strand from one subunit is incorporated into a β-sheet of the next subunit. Our results reveal likely mechanistic similarities and evolutionary connection between bacterial and archaeal biofilms, and suggest that there could be many other archaeal surface filaments that are as yet uncharacterized.
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130
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Li Z, Zheng Y, Li Y, Cheng X, Huang S, Yang X, Qin Y. Genotype-Specific Recruitment of Rhizosphere Bacteria From Sandy Loam Soil for Growth Promotion of Cucumis sativus var. hardwickii. Front Microbiol 2022; 13:910644. [PMID: 35832804 PMCID: PMC9271904 DOI: 10.3389/fmicb.2022.910644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/11/2022] [Indexed: 11/16/2022] Open
Abstract
The composition and structure of the rhizosphere microbiome is affected by many factors, including soil type, genotype, and cultivation time of the plant. However, the interaction mechanisms among these factors are largely unclear. We use culture-independent 16S rRNA amplicon sequencing to investigate the rhizosphere bacterial composition and the structure of cultivated cucumber Xintaimici (XT) and wild-type cucumber Cucumis sativus var. hardwickii (HD) in four kinds of soils. We found that soil type, cultivation time, and genotype affected the composition and structure of cucumber rhizosphere bacterial communities. Notably, HD showed better physiological features in sandy soil and sandy loam soil than it did in black soil and farm soil at 50 days post-sowing, which was due to its stronger recruitment ability to Nitrospira, Nocardioides, Bacillus, and Gaiella in sandy soil, and more Tumebacillus, Nitrospira, and Paenibacillus in sandy loam soil. Meanwhile, we also found that HD showed a better recruiting capacity for these bacterial genera than XT in both sandy soil and sandy loam soil. Functional predictions indicated that these bacteria might have had stronger root colonization ability and then promoted the growth of cucumbers by enhancing nitrogen metabolism and active metabolite secretion. In this study, our findings provided a better insight into the relationship between cucumber phenotype, genotype, and the rhizosphere bacterial community, which will offer valuable theoretical references for rhizosphere microbiota studies and its future application in agriculture.
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Affiliation(s)
- Zeyang Li
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yingying Zheng
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yansu Li
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xu Cheng
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Sanwen Huang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
- *Correspondence: Sanwen Huang,
| | - Xueyong Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
- Xueyong Yang,
| | - Yuxuan Qin
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
- Yuxuan Qin,
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131
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Probing the growth and mechanical properties of Bacillus subtilis biofilms through genetic mutation strategies. Synth Syst Biotechnol 2022; 7:965-971. [PMID: 35756965 PMCID: PMC9194759 DOI: 10.1016/j.synbio.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 12/02/2022] Open
Abstract
Bacterial communities form biofilms on various surfaces by synthesizing a cohesive and protective extracellular matrix, and these biofilms protect microorganisms against harsh environmental conditions. Bacillus subtilis is a widely used experimental species, and its biofilms are used as representative models of beneficial biofilms. Specifically, B. subtilis biofilms are known to be rich in extracellular polymeric substances (EPS) and other biopolymers such as DNA and proteins like the amyloid protein TasA and the hydrophobic protein BslA. These materials, which form an interconnected, cohesive, three-dimensional polymer network, provide the mechanical stability of biofilms and mediate their adherence to surfaces among other functional contributions. Here, we explored how genetically-encoded components specifically contribute to regulate the growth status, mechanical properties, and antibiotic resistance of B. subtilis biofilms, thereby establishing a solid empirical basis for understanding how various genetic engineering efforts are likely to affect the structure and function of biofilms. We noted discrete contributions to biofilm morphology, mechanical properties, and survival from major biofilm components such as EPS, TasA and BslA. For example, EPS plays an important role in maintaining the stability of the mechanical properties and the antibiotic resistance of biofilms, whereas BslA has a significant impact on the resolution that can be obtained for printing applications. This work provides a deeper understanding of the internal interactions of biofilm components through systematic genetic manipulations. It thus not only broadens the application prospects of beneficial biofilms, but also serves as the basis of future strategies for targeting and effectively removing harmful biofilms.
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132
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Yamamoto J, Chumsakul O, Toya Y, Morimoto T, Liu S, Masuda K, Kageyama Y, Hirasawa T, Matsuda F, Ogasawara N, Shimizu H, Yoshida KI, Oshima T, Ishikawa S. Constitutive expression of the global regulator AbrB restores the growth defect of a genome-reduced Bacillus subtilis strain and improves its metabolite production. DNA Res 2022; 29:6591218. [PMID: 35608323 PMCID: PMC9160880 DOI: 10.1093/dnares/dsac015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 05/19/2022] [Indexed: 12/02/2022] Open
Abstract
Partial bacterial genome reduction by genome engineering can improve the productivity of various metabolites, possibly via deletion of non-essential genome regions involved in undesirable metabolic pathways competing with pathways for the desired end products. However, such reduction may cause growth defects. Genome reduction of Bacillus subtilis MGB874 increases the productivity of cellulases and proteases but reduces their growth rate. Here, we show that this growth defect could be restored by silencing redundant or less important genes affecting exponential growth by manipulating the global transcription factor AbrB. Comparative transcriptome analysis revealed that AbrB-regulated genes were upregulated and those involved in central metabolic pathway and synthetic pathways of amino acids and purine/pyrimidine nucleotides were downregulated in MGB874 compared with the wild-type strain, which we speculated were the cause of the growth defects. By constitutively expressing high levels of AbrB, AbrB regulon genes were repressed, while glycolytic flux increased, thereby restoring the growth rate to wild-type levels. This manipulation also enhanced the productivity of metabolites including γ-polyglutamic acid. This study provides the first evidence that undesired features induced by genome reduction can be relieved, at least partly, by manipulating a global transcription regulation system. A similar strategy could be applied to other genome engineering-based challenges aiming toward efficient material production in bacteria.
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Affiliation(s)
- Junya Yamamoto
- Graduate School of Science, Technology and Innovation, Kobe University , Nada, Kobe 657-8501, Japan
| | - Onuma Chumsakul
- Graduate School of Biological Sciences, Nara Institute of Science and Technology , Ikoma, Nara 630-0192, Japan
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University , Suita, Osaka 565-0871, Japan
| | - Takuya Morimoto
- Biological Science Laboratories, Kao Corporation , Akabane, Tochigi 321-3497, Japan
| | - Shenghao Liu
- Biological Science Laboratories, Kao Corporation , Akabane, Tochigi 321-3497, Japan
| | - Kenta Masuda
- Biological Science Laboratories, Kao Corporation , Akabane, Tochigi 321-3497, Japan
| | - Yasushi Kageyama
- Biological Science Laboratories, Kao Corporation , Akabane, Tochigi 321-3497, Japan
| | - Takashi Hirasawa
- School of Life Science and Technology, Tokyo Institute of Technology , Yokohama, Kanagawa 226-8501, Japan
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University , Suita, Osaka 565-0871, Japan
| | - Naotake Ogasawara
- Graduate School of Biological Sciences, Nara Institute of Science and Technology , Ikoma, Nara 630-0192, Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University , Suita, Osaka 565-0871, Japan
| | - Ken-ichi Yoshida
- Graduate School of Science, Technology and Innovation, Kobe University , Nada, Kobe 657-8501, Japan
| | - Taku Oshima
- Department of Biotechnology, Toyama Prefectural University , Imizu, Toyama 939-0398, Japan
| | - Shu Ishikawa
- Graduate School of Science, Technology and Innovation, Kobe University , Nada, Kobe 657-8501, Japan
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133
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Pangenome analyses of Bacillus pumilus, Bacillus safensis, and Priestia megaterium exploring the plant-associated features of bacilli strains isolated from canola. Mol Genet Genomics 2022; 297:1063-1079. [PMID: 35612623 DOI: 10.1007/s00438-022-01907-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 05/05/2022] [Indexed: 12/11/2022]
Abstract
Previous genome mining of the strains Bacillus pumilus 7PB, Bacillus safensis 1TAz, 8Taz, and 32PB, and Priestia megaterium 16PB isolated from canola revealed differences in the profile of antimicrobial biosynthetic genes when compared to the species type strains. To evaluate not only the similarities among B. pumilus, B. safensis, and P. megaterium genomes but also the specificities found in the canola bacilli, we performed comparative genomic analyses through the pangenome evaluation of each species. Besides that, other genome features were explored, especially focusing on plant-associated and biotechnological characteristics. The combination of the genome metrics Average Nucleotide Identity and digital DNA-DNA hybridization formulas 1 and 3 adopting the universal thresholds of 95 and 70%, respectively, was suitable to verify the identification of strains from these groups. On average, core genes corresponded to 45%, 52%, and 34% of B. pumilus, B. safensis, and P. megaterium open pangenomes, respectively. Many genes related to adaptations to plant-associated lifestyles were predicted, especially in the Bacillus genomes. These included genes for acetoin production, polyamines utilization, root exudate chemoreceptors, biofilm formation, and plant cell-wall degrading enzymes. Overall, we could observe that strains of these species exhibit many features in common, whereas most of their variable genome portions have features yet to be uncovered. The observed antifungal activity of canola bacilli might be a result of the synergistic action of secondary metabolites, siderophores, and chitinases. Genome analysis confirmed that these species and strains have biotechnological potential to be used both as agricultural inoculants or hydrolases producers. Up to our knowledge, this is the first work that evaluates the pangenome features of P. megaterium.
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134
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Holtrup S, Graumann PL. Strain-dependent motility defects and suppression by a flhO mutation for B. subtilis bactofilins. BMC Res Notes 2022; 15:168. [PMID: 35562765 PMCID: PMC9103452 DOI: 10.1186/s13104-022-06048-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 04/24/2022] [Indexed: 11/22/2022] Open
Abstract
Objective Bactofilins can assemble into polymeric structures and play important roles in cell shape maintenance, chromosome segregation and motility. Bacillus subtilis bactofilins BacE and BacF were shown to be important for swimming motility in strain PY79, and single gene deletions were reported to be lethal, in contrast to a double bacEF deletion. Results Extending this work, we show that motility defects vary between different B. subtilis strains, with strain 168 showing no defect in motility, and 3610 showing delayed induction of swimming. Generation of single gene deletions in PY79 was possible by transferring corresponding deletions from 168. In the natural isolate 3610, gene deletions also showed a negative effect on biofilm formation, revealing an additional function for BacE and BacF. A spontaneous arising suppressor mutation in PY79 was mapped to the flhO gene, a constituent of the flagellum, which obtained an 18 amino acid extension at its C-terminus. Our findings show that bactofilin gene deletions lead to different motility phenotypes dependent on the strain background, and affect biofilm formation in the natural isolate 3610. Our data reinforce the idea of a connection between bactofilins and motion via the flagellum, and suggest that they operate in a switch like manner. Supplementary Information The online version contains supplementary material available at 10.1186/s13104-022-06048-6.
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Affiliation(s)
- Sven Holtrup
- SYNMIKRO, Zentrum Für Synthetische Mikrobiologie, Karl-von-Frisch-Str. 14, 35043, Marburg, Germany.,Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032, Marburg, Germany
| | - Peter L Graumann
- SYNMIKRO, Zentrum Für Synthetische Mikrobiologie, Karl-von-Frisch-Str. 14, 35043, Marburg, Germany. .,Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032, Marburg, Germany.
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135
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Dye KJ, Yang Z. Analysis of Myxococcus xanthus Vegetative Biofilms With Microtiter Plates. Front Microbiol 2022; 13:894562. [PMID: 35572678 PMCID: PMC9100584 DOI: 10.3389/fmicb.2022.894562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
The bacterium Myxococcus xanthus forms both developmental and vegetative types of biofilms. While the former has been studied on both agar plates and submerged surfaces, the latter has been investigated predominantly on agar surfaces as swarming colonies. Here we describe the development of a microplate-based assay for the submerged biofilms of M. xanthus under vegetative conditions. We examined the impacts of inoculation, aeration, and temperature to optimize the conditions for the assay. Aeration was observed to be critical for the effective development of submerged biofilms by M. xanthus, an obligate aerobic bacterium. In addition, temperature plays an important role in the development of M. xanthus submerged biofilms. It is well established that the formation of submerged biofilms by many bacteria requires both exopolysaccharide (EPS) and the type IV pilus (T4P). EPS constitutes part of the biofilm matrix that maintains and organizes bacterial biofilms while the T4P facilitates surface attachment as adhesins. For validation, we used our biofilm assay to examine a multitude of M. xanthus strains with various EPS and T4P phenotypes. The results indicate that the levels of EPS, but not of piliation, positively correlate with submerged biofilm formation in M. xanthus.
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136
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Fessia A, Barra P, Barros G, Nesci A. Could Bacillus biofilms enhance the effectivity of biocontrol strategies in the phyllosphere? J Appl Microbiol 2022; 133:2148-2166. [PMID: 35476896 DOI: 10.1111/jam.15596] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/13/2022] [Accepted: 04/21/2022] [Indexed: 11/30/2022]
Abstract
Maize (Zea mays L.), a major crop in Argentina and a staple food around the world, is affected by the emergence and re-emergence of foliar diseases. Agrochemicals are the main control strategy nowadays, but they can cause resistance in insects and microbial pathogens and have negative effects on the environment and human health. An emerging alternative is the use of living organisms, i.e. microbial biocontrol agents, to suppress plant pathogen populations. This is a risk-free approach when the organisms acting as biocontrol agents come from the same ecosystem as the foliar pathogens they are meant to antagonize. Some epiphytic microorganisms may form biofilm by becoming aggregated and attached to a surface, as is the case of spore-forming bacteria from the genus Bacillus. Their ability to sporulate and their tolerance to long storage periods make them a frequently used biocontrol agent. Moreover, the biofilm that they create protects them against different abiotic and biotic factors and helps them to acquire nutrients, which ensures their survival on the plants they protect. This review analyzes the interactions that the phyllosphere-inhabiting Bacillus genus establishes with its environment through biofilm, and how this lifestyle could serve to design effective biological control strategies.
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Affiliation(s)
- Aluminé Fessia
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Paula Barra
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Germán Barros
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
| | - Andrea Nesci
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ruta Nacional 36, Km 601, X5804ZAB Río Cuarto, Córdoba, Argentina
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137
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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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138
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Krujatz F, Dani S, Windisch J, Emmermacher J, Hahn F, Mosshammer M, Murthy S, Steingroewer J, Walther T, Kühl M, Gelinsky M, Lode A. Think outside the box: 3D bioprinting concepts for biotechnological applications – recent developments and future perspectives. Biotechnol Adv 2022; 58:107930. [DOI: 10.1016/j.biotechadv.2022.107930] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/17/2022] [Indexed: 12/14/2022]
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139
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An Introduction to Bacterial Biofilms and Their Proteases, and Their Roles in Host Infection and Immune Evasion. Biomolecules 2022; 12:biom12020306. [PMID: 35204806 PMCID: PMC8869686 DOI: 10.3390/biom12020306] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/03/2022] [Accepted: 02/10/2022] [Indexed: 12/15/2022] Open
Abstract
Bacterial biofilms represent multicellular communities embedded in a matrix of extracellular polymeric substances, conveying increased resistance against environmental stress factors but also antibiotics. They are shaped by secreted enzymes such as proteases, which can aid pathogenicity by degrading host proteins of the connective tissue or the immune system. Importantly, both secreted proteases and the capability of biofilm formation are considered key virulence factors. In this review, we focus on the basic aspects of proteolysis and protein secretion, and highlight various secreted bacterial proteases involved in biofilm establishment and dispersal, and how they aid bacteria in immune evasion by degrading immunoglobulins and components of the complement system. Thus, secreted proteases represent not only prominent antimicrobial targets but also enzymes that can be used for dedicated applications in biotechnology and biomedicine, including their use as laundry detergents, in mass spectrometry for the glycoprofiling of antibodies, and the desensitization of donor organs intended for positive crossmatch patients.
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140
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Mahapatra S, Yadav R, Ramakrishna W. Bacillus subtilis Impact on Plant Growth, Soil Health and Environment: Dr. Jekyll and Mr. Hyde. J Appl Microbiol 2022; 132:3543-3562. [PMID: 35137494 DOI: 10.1111/jam.15480] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/04/2022] [Indexed: 11/29/2022]
Abstract
The increased dependence of farmers on chemical fertilizers poses a risk to soil fertility and ecosystem stability. Plant growth-promoting rhizobacteria (PGPR) are at the forefront of sustainable agriculture, providing multiple benefits for the enhancement of crop production and soil health. Bacillus subtilis is a common PGPR in soil that plays a key role in conferring biotic and abiotic stress tolerance to plants by induced systemic resistance (ISR), biofilm formation, and lipopeptide production. As a part of bioremediating technologies, Bacillus spp. can purify metal contaminated soil. It acts as a potent denitrifying agent in agroecosystems while improving the carbon sequestration process when applied in a regulated concentration. Although it harbors several antibiotic resistance genes (ARGs), it can reduce the horizontal transfer of ARGs during manure composting by modifying the genetic makeup of existing microbiota. In some instances, it affects the beneficial microbes of the rhizosphere. External inoculation of B. subtilis has both positive and negative impacts on the endophytic and semi-synthetic microbial community. Soil texture, type, pH, and bacterial concentration play a crucial role in the regulation of all these processes. Soil amendments and microbial consortia of Bacillus produced by microbial engineering could be used to lessen the negative effect on soil microbial diversity. The complex plant-microbe interactions could be decoded using transcriptomics, proteomics, metabolomics, and epigenomics strategies which would be beneficial for both crop productivity and the well-being of soil microbiota. Bacillus subtilis has more positive attributes similar to the character of Dr. Jekyll and some negative attributes on plant growth, soil health, and the environment akin to the character of Mr. Hyde.
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141
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Luise D, Bosi P, Raff L, Amatucci L, Virdis S, Trevisi P. Bacillus spp. Probiotic Strains as a Potential Tool for Limiting the Use of Antibiotics, and Improving the Growth and Health of Pigs and Chickens. Front Microbiol 2022; 13:801827. [PMID: 35197953 PMCID: PMC8859173 DOI: 10.3389/fmicb.2022.801827] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/14/2022] [Indexed: 01/20/2023] Open
Abstract
The pressure to increasingly optimize the breeding of livestock monogastric animals resulted in antimicrobials often being misused in an attempt to improve growth performance and counteract diseases in these animals, leading to an increase in the problem of antibiotic resistance. To tackle this problem, the use of probiotics, also known as direct in-feed microbials (DFM), seems to be one of the most promising strategies. Among probiotics, the interest in Bacillus strains has been intensively increased in recent decades in pigs and poultry. The aim of the present review was to evaluate the effectiveness of Bacillus strains as probiotics and as a potential strategy for reducing the misuse of antibiotics in monogastric animals. Thus, the potential modes of action, and the effects on the performance and health of pigs (weaning pigs, lactation and gestation sows) and broilers are discussed. These searches yielded 131 articles (published before January 2021). The present review showed that Bacillus strains could favor growth in terms of the average daily gain (ADG) of post-weaning piglets and broilers, and reduce the incidence of post-weaning diarrhea in pigs by 30% and mortality in broilers by 6-8%. The benefits of Bacillus strains on these parameters showed results comparable to the benefit obtained by the use of antibiotics. Furthermore, the use of Bacillus strains gives promising results in enhancing the local adaptative immune response and in reducing the oxidative stress of broilers. Fewer data were available regarding the effect on sows. Discordant effects have been reported regarding the effect on body weight (BW) and feed intake while a number of studies have supported the hypothesis that feeding probiotics to sows could benefit their reproductive performance, namely the BW and ADG of the litters. Taken all the above-mentioned facts together, this review confirmed the effectiveness of Bacillus strains as probiotics in young pigs and broilers, favoring their health and contributing to a reduction in the misuse of direct in-feed antibiotics. The continuous development and research regarding probiotics will support a decrease in the misuse of antibiotics in livestock production in order to endorse a more sustainable rearing system in the near future.
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Affiliation(s)
- Diana Luise
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Paolo Bosi
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Lena Raff
- Chr. Hansen, Animal Health and Nutrition, Hørsholm, Denmark
| | - Laura Amatucci
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Sara Virdis
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Paolo Trevisi
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
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142
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Simultaneous and selective production of exopolymers and polyols by metabolically engineered Bacillus licheniformis strains. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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143
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Lin Y, Briandet R, Kovács ÁT. Bacillus cereus sensu lato biofilm formation and its ecological importance. Biofilm 2022; 4:100070. [PMID: 35243332 PMCID: PMC8861577 DOI: 10.1016/j.bioflm.2022.100070] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 12/20/2022] Open
Abstract
Biofilm formation is a ubiquitous process of bacterial communities that enables them to survive and persist in various environmental niches. The Bacillus cereus group includes phenotypically diversified species that are widely distributed in the environment. Often, B. cereus is considered a soil inhabitant, but it is also commonly isolated from plant roots, nematodes, and food products. Biofilms differ in their architecture and developmental processes, reflecting adaptations to specific niches. Importantly, some B. cereus strains are foodborne pathogens responsible for two types of gastrointestinal diseases, diarrhea and emesis, caused by distinct toxins. Thus, the persistency of biofilms is of particular concern for the food industry, and understanding the underlying mechanisms of biofilm formation contributes to cleaning procedures. This review focuses on the genetic background underpinning the regulation of biofilm development, as well as the matrix components associated with biofilms. We also reflect on the correlation between biofilm formation and the development of highly resistant spores. Finally, advances in our understanding of the ecological importance and evolution of biofilm formation in the B. cereus group are discussed.
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144
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Maan H, Itkin M, Malitsky S, Friedman J, Kolodkin-Gal I. Resolving the conflict between antibiotic production and rapid growth by recognition of peptidoglycan of susceptible competitors. Nat Commun 2022; 13:431. [PMID: 35058430 PMCID: PMC8776889 DOI: 10.1038/s41467-021-27904-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 12/16/2021] [Indexed: 11/09/2022] Open
Abstract
Microbial communities employ a variety of complex strategies to compete successfully against competitors sharing their niche, with antibiotic production being a common strategy of aggression. Here, by systematic evaluation of four non-ribosomal peptides/polyketide (NRPs/PKS) antibiotics produced by Bacillus subtilis clade, we revealed that they acted synergistically to effectively eliminate phylogenetically distinct competitors. The production of these antibiotics came with a fitness cost manifested in growth inhibition, rendering their synthesis uneconomical when growing in proximity to a phylogenetically close species, carrying resistance against the same antibiotics. To resolve this conflict and ease the fitness cost, antibiotic production was only induced by the presence of a peptidoglycan cue from a sensitive competitor, a response mediated by the global regulator of cellular competence, ComA. These results experimentally demonstrate a general ecological concept - closely related communities are favoured during competition, due to compatibility in attack and defence mechanisms.
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Affiliation(s)
- Harsh Maan
- Department of Molecular Genetics, Weizmann Institute of Science, 234 Herzl Street, 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
| | - Jonathan Friedman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ilana Kolodkin-Gal
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
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145
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Sanchez-Vizuete P, Dergham Y, Bridier A, Deschamps J, Dervyn E, Hamze K, Aymerich S, Le Coq D, Briandet R. The coordinated population redistribution between Bacillus subtilis submerged biofilm and liquid-air pellicle. Biofilm 2022; 4:100065. [PMID: 35024609 PMCID: PMC8732777 DOI: 10.1016/j.bioflm.2021.100065] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 12/15/2022] Open
Abstract
Bacillus subtilis is a widely used bacterial model to decipher biofilm formation, genetic determinants and their regulation. For several years, studies were conducted on colonies or pellicles formed at the interface with air, but more recent works showed that non-domesticated strains were able to form thick and structured biofilms on submerged surfaces. Taking advantage of time-lapse confocal laser scanning microscopy, we monitored bacterial colonization on the surface and observed an unexpected biphasic submerged biofilm development. Cells adhering to the surface firstly form elongated chains before being suddenly fragmented and released as free motile cells in the medium. This switching coincided with an oxygen depletion in the well which preceded the formation of the pellicle at the liquid-air interface. Residual bacteria still associated with the solid surface at the bottom of the well started to express matrix genes under anaerobic metabolism to build the typical biofilm protruding structures.
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Affiliation(s)
- Pilar Sanchez-Vizuete
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Yasmine Dergham
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.,Faculty of Science, Lebanese University, 1003, Beirut, Lebanon
| | - Arnaud Bridier
- Fougères Laboratory, Antibiotics, Biocides, Residues and Resistance Unit, Anses, 35300, Fougères, France
| | - Julien Deschamps
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Etienne Dervyn
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Kassem Hamze
- Faculty of Science, Lebanese University, 1003, Beirut, Lebanon
| | - Stéphane Aymerich
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Dominique Le Coq
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.,Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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146
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Gorreja F, Walker WA. The potential role of adherence factors in probiotic function in the gastrointestinal tract of adults and pediatrics: a narrative review of experimental and human studies. Gut Microbes 2022; 14:2149214. [PMID: 36469568 PMCID: PMC9728474 DOI: 10.1080/19490976.2022.2149214] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Numerous studies point to the important role of probiotic bacteria in gastrointestinal health. Probiotics act through mechanisms affecting enteric pathogens, epithelial barrier function, immune signaling, and conditioning of indigenous microbiota. Once administered, probiotics reach the gastrointestinal tract and interact with the host through bacterial surface molecules, here called adhesion factors, which are either strain- or specie-specific. Probiotic adhesion, through structural adhesion factors, is a mechanism that facilitates persistence within the gastrointestinal tract and triggers the initial host responses. Thus, an understanding of specific probiotic adhesion mechanisms could predict how specific probiotic strains elicit benefits and the potential of adherence factors as a proxy to predict probiotic function. This review summarizes the present understanding of probiotic adherence in the gastrointestinal tract. It highlights the bacterial adhesion structure types, their molecular communication with the host and the consequent impact on intestinal diseases in both adult and pediatric populations. Finally, we discuss knockout/isolation studies as direct evidence for adhesion factors conferring anti-inflammatory and pathogen inhibition properties to a probiotic.What is known: Probiotics can be used to treat clinical conditions.Probiotics improve dysbiosis and symptoms.Clinical trials may not confirm in vitro and animal studies.What is new: Adhesion structures may be important for probiotic function.Need to systematically determine physical characteristics of probiotics before selecting for clinical trials.Probiotics may be genetically engineered to add to clinical efficacy.
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Affiliation(s)
- Frida Gorreja
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Nutrition-Gut-Brain Interactions Research Centre, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - W. Allan Walker
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Harvard Medical School, Boston, Massachusetts, USA
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147
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Abstract
Some Bacillus species, such as B. velezensis, are important members of the plant-associated microbiome, conferring protection against phytopathogens. However, our knowledge about multitrophic interactions determining the ecological fitness of these biocontrol bacteria in the competitive rhizosphere niche is still limited. Here, we investigated molecular mechanisms underlying interactions between B. velezensis and Pseudomonas as a soil-dwelling competitor. Upon their contact-independent in vitro confrontation, a multifaceted macroscopic outcome was observed and characterized by Bacillus growth inhibition, white line formation in the interaction zone, and enhanced motility. We correlated these phenotypes with the production of bioactive secondary metabolites and identified specific lipopeptides as key compounds involved in the interference interaction and motile response. Bacillus mobilizes its lipopeptide surfactin not only to enhance motility but also to act as a chemical trap to reduce the toxicity of lipopeptides formed by Pseudomonas. We demonstrated the relevance of these unsuspected roles of lipopeptides in the context of competitive tomato root colonization by the two bacterial genera. IMPORTANCE Plant-associated Bacillus velezensis and Pseudomonas spp. represent excellent model species as strong producers of bioactive metabolites involved in phytopathogen inhibition and the elicitation of plant immunity. However, the ecological role of these metabolites during microbial interspecies interactions and the way their expression may be modulated under naturally competitive soil conditions has been poorly investigated. Through this work, we report various phenotypic outcomes from the interactions between B. velezensis and 10 Pseudomonas strains used as competitors and correlate them with the production of specific metabolites called lipopeptides from both species. More precisely, Bacillus overproduces surfactin to enhance motility, which also, by acting as a chemical trap, reduces the toxicity of other lipopeptides formed by Pseudomonas. Based on data from interspecies competition on plant roots, we assume this would allow Bacillus to gain fitness and persistence in its natural rhizosphere niche. The discovery of new ecological functions for Bacillus and Pseudomonas secondary metabolites is crucial to rationally design compatible consortia, more efficient than single-species inoculants, to promote plant health and growth by fighting economically important pathogens in sustainable agriculture.
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148
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Expression of SARS-CoV-2 Spike Protein Receptor Binding Domain on Recombinant B. subtilis on Spore Surface: A Potential COVID-19 Oral Vaccine Candidate. Vaccines (Basel) 2021; 10:vaccines10010002. [PMID: 35062663 PMCID: PMC8780001 DOI: 10.3390/vaccines10010002] [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: 11/15/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 12/11/2022] Open
Abstract
Various types of vaccines, such as mRNA, adenovirus, and inactivated virus by injection, have been developed to prevent SARS-CoV-2 infection. Although some of them have already been approved under the COVID-19 pandemic, various drawbacks, including severe side effects and the requirement for sub-zero temperature storage, may hinder their applications. Bacillus subtilis (B. subtilis) is generally recognized as a safe and endotoxin-free Gram-positive bacterium that has been extensively employed as a host for the expression of recombinant proteins. Its dormant spores are extraordinarily resistant to the harsh environment in the gastrointestinal tract. This feature makes it an ideal carrier for oral administration in resisting this acidic environment and for release in the intestine. In this study, an engineered B. subtilis spore expressing the SARS-CoV-2 spike protein receptor binding domain (sRBD) on the spore surface was developed. In a pilot test, no adverse health event was observed in either mice or healthy human volunteers after three oral courses of B. subtilis spores. Significant increases in neutralizing antibody against sRBD, in both mice and human volunteers, after oral administration were also found. These findings may enable the further clinical developments of B. subtilis spores as an oral vaccine candidate against COVID-19 in the future.
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149
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Abstract
Bacillus subtilis is a soil bacterium that can form biofilms, which are communities of cells encased by an extracellular matrix. In these complex communities, cells perform numerous metabolic processes and undergo differentiation into functionally distinct phenotypes as a survival strategy. Because biofilms are often studied in bulk, it remains unclear how metabolite production spatially correlates with B. subtilis phenotypes within biofilm structures. In many cases, we still do not know where these biological processes are occurring in the biofilm. Here, we developed a method to analyze the localization of molecules within sagittal thin sections of B. subtilis biofilms using high-resolution mass spectrometry imaging. We correlated the organization of specific molecules to the localization of well-studied B. subtilis phenotypic reporters determined by confocal laser scanning fluorescence microscopy within analogous biofilm thin sections. The correlations between these two data sets suggest the role of surfactin as a signal for extracellular matrix gene expression in the biofilm periphery and the role of bacillibactin as an iron-scavenging molecule. Taken together, this method will help us generate hypotheses to discover relationships between metabolites and phenotypic cell states in B. subtilis and other biofilm-forming bacteria. IMPORTANCE Bacterial biofilms are complex and heterogeneous structures. Cells within biofilms carry out numerous metabolic processes in a nuanced and organized manner, details of which are still being discovered. Here, we used multimodal imaging to analyze B. subtilis biofilm processes at the metabolic and gene expression levels in biofilm sagittal thin sections. Often, imaging techniques analyze only the top of the surface of the biofilm and miss the multifaceted interactions that occur deep within the biofilm. Our analysis of the sagittal planes of B. subtilis biofilms revealed the distributions of metabolic processes throughout the depths of these structures and allowed us to draw correlations between metabolites and phenotypically important subpopulations of B. subtilis cells. This technique provides a platform to generate hypotheses about the role of specific molecules and their relationships to B. subtilis subpopulations of cells.
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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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