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Robertson JM, Garza EA, Stubbusch AKM, Dupont CL, Hwa T, Held NA. Marine bacteria Alteromonas spp. require UDP-glucose-4-epimerase for aggregation and production of sticky exopolymer. mBio 2024:e0003824. [PMID: 38958440 DOI: 10.1128/mbio.00038-24] [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: 01/06/2024] [Accepted: 05/23/2024] [Indexed: 07/04/2024] Open
Abstract
The physiology and ecology of particle-associated marine bacteria are of growing interest, but our knowledge of their aggregation behavior and mechanisms controlling their association with particles remains limited. We have found that a particle-associated isolate, Alteromonas sp. ALT199 strain 4B03, and the related type-strain A. macleodii 27126 both form large (>500 μm) aggregates while growing in rich medium. A non-clumping variant (NCV) of 4B03 spontaneously arose in the lab, and whole-genome sequencing revealed a partial deletion in the gene encoding UDP-glucose-4-epimerase (galEΔ308-324). In 27126, a knock-out of galE (ΔgalE::kmr) resulted in a loss of aggregation, mimicking the NCV. Microscopic analysis shows that both 4B03 and 27126 rapidly form large aggregates, whereas their respective galE mutants remain primarily as single planktonic cells or clusters of a few cells. Strains 4B03 and 27126 also form aggregates with chitin particles, but their galE mutants do not. Alcian Blue staining shows that 4B03 and 27126 produce large transparent exopolymer particles (TEP), but their galE mutants are deficient in this regard. This study demonstrates the capabilities of cell-cell aggregation, aggregation of chitin particles, and production of TEP in strains of Alteromonas, a widespread particle-associated genus of heterotrophic marine bacteria. A genetic requirement for galE is evident for each of the above capabilities, expanding the known breadth of requirement for this gene in biofilm-related processes. IMPORTANCE Heterotrophic marine bacteria have a central role in the global carbon cycle. Well-known for releasing CO2 by decomposition and respiration, they may also contribute to particulate organic matter (POM) aggregation, which can promote CO2 sequestration via the formation of marine snow. We find that two members of the prevalent particle-associated genus Alteromonas can form aggregates comprising cells alone or cells and chitin particles, indicating their ability to drive POM aggregation. In line with their multivalent aggregation capability, both strains produce TEP, an excreted polysaccharide central to POM aggregation in the ocean. We demonstrate a genetic requirement for galE in aggregation and large TEP formation, building our mechanistic understanding of these aggregative capabilities. These findings point toward a role for heterotrophic bacteria in POM aggregation in the ocean and support broader efforts to understand bacterial controls on the global carbon cycle based on microbial activities, community structure, and meta-omic profiling.
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Affiliation(s)
- Jacob M Robertson
- Division of Biological Sciences, UC San Diego, La Jolla, California, USA
| | - Erin A Garza
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, California, USA
| | - Astrid K M Stubbusch
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Department of Earth Sciences, Geological Institute, ETH Zurich, Zurich, Switzerland
| | - Christopher L Dupont
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, California, USA
| | - Terence Hwa
- Division of Biological Sciences, UC San Diego, La Jolla, California, USA
- Department of Physics, UC San Diego, La Jolla, California, USA
| | - Noelle A Held
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich, Switzerland
- Department of Environmental Microbiology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, California, USA
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Zhang L, Fu Y, Xu Q, Chen X, Xie Y, Zhang B, Lin X. Quantitative proteomics reveals the complex regulatory networks of LTTR-type regulators in pleiotropic functions of Aeromonas hydrophila. Int J Biol Macromol 2024; 270:132315. [PMID: 38740149 DOI: 10.1016/j.ijbiomac.2024.132315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
LysR-type transcriptional regulators (LTTRs) are ubiquitously distributed and abundant transcriptional regulators in prokaryotes, playing pivotal roles in diverse physiological processes. Nonetheless, despite their prevalence, the intricate functionalities and physiological implications of this protein family remain incompletely elucidated. In this study, we employed a comprehensive approach to deepen our understanding of LTTRs by generating a collection of 20 LTTR gene-deletion strains in Aeromonas hydrophila, accounting for 42.6 % of the predicted total LTTR repertoire, and subjected them to meticulous assessment of their physiological phenotypes. Leveraging quantitative proteomics, we conducted a comparative analysis of protein expression variations between six representative mutants and the wild-type strain. Subsequent bioinformatics analysis unveiled the involvement of these LTTRs in modulating a wide array of biological processes, notably including two-component regulatory systems (TCSs) and intracellular central metabolism. Moreover, employing subsequent microbiological methodologies, we experimentally verified the direct involvement of at least six LTTRs in the regulation of galactose metabolism. Importantly, through ELISA and competitive ELISA assays, we demonstrated the competitive binding capabilities of these LTTRs with the promoter of the α-galactosidase gene AHA_1897 and identified that four LTTRs (XapR, YidZ, YeeY, and AHA_1805) do not engage in competitive binding with other LTTRs. Overall, our comprehensive findings not only provide fundamental insights into the regulatory mechanisms governing crucial physiological functions of bacteria through LTTR family proteins but also uncover an intricate and interactive regulatory network mediated by LTTRs.
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Affiliation(s)
- Lishan Zhang
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuying Fu
- School of Safety and Environment, Fujian Chuanzheng Communications College, Fuzhou, Fujian Province 350007, China
| | - Qiaozhen Xu
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xin Chen
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuyue Xie
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Binghui Zhang
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Tobacco Science, Fujian Provincial Tobacco Company, Fuzhou 350003, China
| | - Xiangmin Lin
- College of JunCao Science and Ecology, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fujian Province University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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3
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Xue Y, Yu C, Ouyang H, Huang J, Kang X. Uncovering the Molecular Composition and Architecture of the Bacillus subtilis Biofilm via Solid-State NMR Spectroscopy. J Am Chem Soc 2024; 146:11906-11923. [PMID: 38629727 DOI: 10.1021/jacs.4c00889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The complex and dynamic compositions of biofilms, along with their sophisticated structural assembly mechanisms, endow them with exceptional capabilities to thrive in diverse conditions that are typically unfavorable for individual cells. Characterizing biofilms in their native state is significantly challenging due to their intrinsic complexities and the limited availability of noninvasive techniques. Here, we utilized solid-state nuclear magnetic resonance (NMR) spectroscopy to analyze Bacillus subtilis biofilms in-depth. Our data uncover a dynamically distinct organization within the biofilm: a dominant, hydrophilic, and mobile framework interspersed with minor, rigid cores of limited water accessibility. In these heterogeneous rigid cores, the major components are largely self-assembled. TasA fibers, the most robust elements, further provide a degree of mechanical support for the cell aggregates and some lipid vesicles. Notably, rigid cell aggregates can persist even without the major extracellular polymeric substance (EPS) polymers, although this leads to slight variations in their rigidity and water accessibility. Exopolysaccharides are exclusively present in the mobile domain, playing a pivotal role in its water retention property. Specifically, all water molecules are tightly bound within the biofilm matrix. These findings reveal a dual-layered defensive strategy within the biofilm: a diffusion barrier through limited water mobility in the mobile phase and a physical barrier posed by limited water accessibility in the rigid phase. Complementing these discoveries, our comprehensive, in situ compositional analysis is not only essential for delineating the sophisticated biofilm architecture but also reveals the presence of alternative genetic mechanisms for synthesizing exopolysaccharides beyond the known pathway.
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Affiliation(s)
- Yi Xue
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Chenjie Yu
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Han Ouyang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Jiaofang Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xue Kang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China
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4
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Sun Y, Shuai W, Nie L, Li X, Jiang L. Investigating the Role of OrbF in Biofilm Biosynthesis and Regulation of Biofilm-Associated Genes in Bacillus cereus BC1. Foods 2024; 13:638. [PMID: 38472751 DOI: 10.3390/foods13050638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 03/14/2024] Open
Abstract
Bacillus cereus (B. cereus), a prevalent foodborne pathogen, constitutes a substantial risk to food safety due to its pronounced resilience under adverse environmental conditions such as elevated temperatures and ultraviolet radiation. This resilience can be attributed to its capacity for biofilm synthesis and sustained high viability. Our research aimed to elucidate the mechanisms governing biofilm biosynthesis in B. cereus. To this end, we constructed a 5088-mutant library of the B. cereus strain BC1 utilizing the transposon TnYLB-1. Systematic screening of this library yielded mutants exhibiting diminished biofilm formation capabilities. Twenty-four genes associated with the biofilm synthesis were identified by reverse PCR in these mutants, notably revealing a significant reduction in biofilm synthesis upon disruption of the orbF gene in B. cereus BC1. Comparative analysis between the wild type and orbF-deficient BC1 strains (BC1ΔorbF) indicated a marked downregulation (decreased by 11.7% to 96.7%) in the expression of genes implicated in biofilm formation, flagellar assembly, and bacterial chemotaxis in the BC1ΔorbF. Electrophoretic mobility shift assay (EMSA) further corroborated the role of OrbF, demonstrating its binding to the promoter region of the biofilm gene cluster, subsequently leading to the suppression of transcriptional activity of biofilm-associated genes in B. cereus BC1. Our findings underscore the pivotal role of orbF in biofilm biosynthesis in B. cereus, highlighting its potential as a target for strategies aimed at mitigating biofilm formation in this pathogen.
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Affiliation(s)
- Yang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Wenjing Shuai
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Lanmengya Nie
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Xiangfei Li
- Engineering Laboratory for Industrial Microbiology Molecular Beeding of Anhui Province, College of Biologic & Food Engineering, Anhui Polytechnic University, 8 Middle Beijing Road, Wuhu 241000, China
| | - Ling Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
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5
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Corbett MK, Gifford A, Fimognari N, Watkin ELJ. Analysis of element yield, bacterial community structure and the impact of carbon sources for bioleaching rare earth elements from high grade monazite. Res Microbiol 2024; 175:104133. [PMID: 37683878 DOI: 10.1016/j.resmic.2023.104133] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
Rare earth element (REE) recovery from waste streams, mine tailings or recyclable components using bioleaching is gaining traction due to the shortage and security of REE supply as well as the environmental problems that occur from processing and refining. Four heterotrophic microbial species with known phosphate solubilizing capabilities were evaluated for their ability to leach REE from a high-grade monazite when provided with either galactose, fructose or maltose. Supplying fructose resulted in the greatest amount of REE leached from the ore due to the largest amount of organic acid produced. Gluconic acid was the dominant organic acid identified produced by the cultures, followed by acetic acid. The monazite proved difficult to leach with the different carbon sources, with preferential release of Ce over La, Nd and Pr.
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Affiliation(s)
- Melissa K Corbett
- Curtin Medical School, Curtin University GPO Box U1987, Perth, Australia.
| | - April Gifford
- Curtin Medical School, Curtin University GPO Box U1987, Perth, Australia.
| | - Nick Fimognari
- School of Science, Edith Cowan University, 270 Joondalup Drive, Joondalup, Australia.
| | - Elizabeth L J Watkin
- Curtin Medical School, Curtin University GPO Box U1987, Perth, Australia; School of Science, Edith Cowan University, 270 Joondalup Drive, Joondalup, Australia.
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6
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Zhang X, Zhang Y, Chen Z, Gu P, Li X, Wang G. Exploring cell aggregation as a defense strategy against perchlorate stress in Chlamydomonas reinhardtii through multi-omics analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167045. [PMID: 37709088 DOI: 10.1016/j.scitotenv.2023.167045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
Perchlorate (ClO4-) is a type of novel, widely distributed, and persistent inorganic pollutant. However, the impacts of perchlorate on freshwater algae remain unclear. In this study, the response and defense mechanisms of microalgae (Chlamydomonas reinhardtii) under perchlorate stress were investigated by integrating physiological and biochemical monitoring, transcriptomics, and metabolomics. Weighted gene co-expression network analysis (WGCNA) of transcriptome data was used to analyze the relationship between genes and phenotype and screen the key pathways. C. reinhardtii exhibited aggregate behavior when exposed to 100- and 200-mM perchlorate but was restored to its unicellular lifestyle when transferred to fresh medium. WGCNA results found that the "carbohydrate metabolism" and "lipid metabolism" pathways were closely related to cell aggregation phenotype. The differential expression genes (DEGs) and differentially accumulated metabolites (DAMs) of these pathways were upregulated, indicating that the lipid and carbohydrate metabolisms were enhanced in aggregated cells. Additionally, most genes and metabolites related to phytohormone abscisic acid (ABA) biosynthesis and the mitogen-activated protein kinase (MAPK) signaling pathway were significantly upregulated, indicating their crucial roles in the signal transmission of aggregated cells. Meanwhile, in aggregated cells, extracellular polymeric substances (EPS) and lipid contents increased, photosynthesis activity decreased, and the antioxidant system was activated. These characteristics contributed to C. reinhardtii's improved resistance to perchlorate stress. Above results demonstrated that cell aggregation behavior was the principal defense strategy of C. reinhardtii against perchlorate. Overall, this study sheds new light on the impact mechanisms of perchlorate to aquatic microalgae and provides multi-omics insights into the research of multicellular-like aggregation as an adaptation strategy to abiotic stress. These results are beneficial for assessing the risk of perchlorate in aquatic environments.
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Affiliation(s)
- Xianyuan Zhang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yixiao Zhang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; School of Science, Tibet University, Lasha 850000, China
| | - Zixu Chen
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peifan Gu
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Li
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Gaohong Wang
- Key Laboratory for Algae Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Raz C, Shemesh M, Argov-Argaman N. The role of milk fat globule size in modulating the composition of postbiotics produced by Bacillus subtilis and their effect on mammary epithelial cells. Food Chem 2023; 427:136730. [PMID: 37392632 DOI: 10.1016/j.foodchem.2023.136730] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/15/2023] [Accepted: 06/24/2023] [Indexed: 07/03/2023]
Abstract
Milk lipids are secreted into the milk collecting ducts as milk fat globule (MFG) where they are exposed to microflora of the udder. We hypothesized that MFG size modulates the metabolic fingerprint of B. subtilis. Accordingly, small and large (2.3 and 7.0 µm, respectively) MFG were isolated from cow milk and used as a substrate for B. subtilis. Small MFG enhanced growth, whereas large MFG enhanced biofilm formation. Bacteria incubated with small MFG had increased concentration of metabolites related to energy production whereas metabolome of the bacteria incubated with large MFG had reduced concentrations of metabolites important for biofilm formation. Postbiotics from bacteria grown on large MFG exacerbated the proinflammatory response of MEC to LPS, and changed the expression of key enzymes involved in lipid and protein synthesis. Our results suggest that MFG size modulate growth trajectories and metabolome of B. subtilis, and consequently the stress response of host cells.
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Affiliation(s)
- Chen Raz
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Israel; Department of Food Sciences, Institute of Postharvest Technology and Food Sciences, Agricultural Research Organization, The Volcani Institute, Rishon LeZion 7528809, Israel.
| | - Moshe Shemesh
- Department of Food Sciences, Institute of Postharvest Technology and Food Sciences, Agricultural Research Organization, The Volcani Institute, Rishon LeZion 7528809, Israel.
| | - Nurit Argov-Argaman
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Israel.
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Xu T, Xiao Y, Wang H, Zhu J, Lu W, Chen W. Multiomics reveals the mechanism of B. longum in promoting the formation of mixed-species biofilms. Food Funct 2023; 14:8276-8290. [PMID: 37602484 DOI: 10.1039/d3fo01751f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
It has been found previously that Bifidobacterium longum, Bacteroides ovatus, Enterococcus faecalis, and Lactobacillus gasseri can form a biofilm better when co-cultured in vitro and B. longum is the core biofilm-formation-promoting strain in this community. B. longum is part of the core microbiota in the gut and is widely recognized as a probiotic. Therefore, it is necessary to explore its role in mixed-species biofilms through transcriptomics and metabolomics. Metabolomics showed that the increase in amino acid and purine content could promote biofilm formation. In transcriptomic analysis, many genes related to carbohydrate metabolism, amino acid metabolism, and environmental tolerance of B. longum were up-regulated. Combined with the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) analysis, the differentially expressed genes (DEGs) of B. longum in mixed-species biofilms were mainly correlated to "quorum sensing (QS)", "ABC transporters", "biosynthesis of amino acids", "microbial metabolism in different environments", "carbohydrate metabolism" and "two-component system". In addition, the rpl and rps gene families, which function in the metabolism of organic substances and the biosynthesis of amino acids, were the core DEGs according to the analysis of the protein-protein interaction (PPI) network. Finally, by combining metabolomics and quorum sensing mechanisms, it was found that the metabolism of autoinducer peptides (proliylglycine and glycylleucine), N-acyl homoserine lactone (N-(3-oxo hydroxy) homoserine lactone), and AI-2 can promote the formation of biofilms, both mono- and mixed-species biofilms composed of B. longum. Our research enabled us to understand the critical role of B. longum in mixed-species biofilms and the interactions between biofilm metabolism and gut health. In addition, the generated knowledge will be of great significance for us to develop biofilm products with beneficial functions in future.
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Affiliation(s)
- Tao Xu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yue Xiao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Hongchao Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jinlin Zhu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wenwei Lu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou 225004, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
| | - Wei Chen
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
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9
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Thieringer PH, Boyd ES, Templeton AS, Spear JR. Metapangenomic investigation provides insight into niche differentiation of methanogenic populations from the subsurface serpentinizing environment, Samail Ophiolite, Oman. Front Microbiol 2023; 14:1205558. [PMID: 37465028 PMCID: PMC10350532 DOI: 10.3389/fmicb.2023.1205558] [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: 04/14/2023] [Accepted: 06/13/2023] [Indexed: 07/20/2023] Open
Abstract
Serpentinization reactions produce highly reduced waters that have hyperalkaline pH and that can have high concentrations of H2 and CH4. Putatively autotrophic methanogenic archaea have been identified in the subsurface waters of the Samail Ophiolite, Sultanate of Oman, though the strategies to overcome hyperalkaline pH and dissolved inorganic carbon limitation remain to be fully understood. Here, we recovered metagenome assembled genomes (MAGs) and applied a metapangenomic approach to three different Methanobacterium populations to assess habitat-specific functional gene distribution. A Type I population was identified in the fluids with neutral pH, while a Type II and "Mixed" population were identified in the most hyperalkaline fluids (pH 11.63). The core genome of all Methanobacterium populations highlighted potential DNA scavenging techniques to overcome phosphate or nitrogen limitation induced by environmental conditions. With particular emphasis on the Mixed and Type II population found in the most hyperalkaline fluids, the accessory genomes unique to each population reflected adaptation mechanisms suggesting lifestyles that minimize niche overlap. In addition to previously reported metabolic capability to utilize formate as an electron donor and generate intracellular CO2, the Type II population possessed genes relevant to defense against antimicrobials and assimilating potential osmoprotectants to provide cellular stability. The accessory genome of the Mixed population was enriched in genes for multiple glycosyltransferases suggesting reduced energetic costs by adhering to mineral surfaces or to other microorganisms, and fostering a non-motile lifestyle. These results highlight the niche differentiation of distinct Methanobacterium populations to circumvent the challenges of serpentinization impacted fluids through coexistence strategies, supporting our ability to understand controls on methanogenic lifestyles and adaptations within the serpentinizing subsurface fluids of the Samail Ophiolite.
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Affiliation(s)
- Patrick H. Thieringer
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, United States
| | - Eric S. Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, United States
| | - Alexis S. Templeton
- Department of Geological Sciences, University of Colorado, Boulder, CO, United States
| | - John R. Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, United States
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Xu F, Liu C, Xia M, Li S, Tu R, Wang S, Jin H, Zhang D. Characterization of a Riboflavin-Producing Mutant of Bacillus subtilis Isolated by Droplet-Based Microfluidics Screening. Microorganisms 2023; 11:microorganisms11041070. [PMID: 37110496 PMCID: PMC10146818 DOI: 10.3390/microorganisms11041070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/17/2023] [Accepted: 03/24/2023] [Indexed: 04/29/2023] Open
Abstract
Bacillus subtilis is one of the commonly used industrial strains for riboflavin production. High-throughput screening is useful in biotechnology, but there are still an insufficient number of articles focusing on improving the riboflavin production of B. subtilis by this powerful tool. With droplet-based microfluidics technology, single cells can be encapsulated in droplets. The screening can be carried out by detecting the fluorescence intensity of secreted riboflavin. Thus, an efficient and high-throughput screening method suitable for riboflavin production strain improvement could be established. In this study, droplet-based microfluidics screening was applied, and a more competitive riboflavin producer U3 was selected from the random mutation library of strain S1. The riboflavin production and biomass of U3 were higher than that of S1 in flask fermentation. In addition, the results of fed-batch fermentation showed that the riboflavin production of U3 was 24.3 g/L, an 18% increase compared with the parent strain S1 (20.6 g/L), and the yield (g riboflavin/100 g glucose) increased by 19%, from 7.3 (S1) to 8.7 (U3). Two mutations of U3 (sinRG89R and icdD28E) were identified through whole genome sequencing and comparison. Then they were introduced into BS168DR (parent of S1) for further analysis, which also caused riboflavin production to increase. This paper provides protocols for screening riboflavin-producing B. subtilis with droplet-based microfluidics technology and reveals mutations in riboflavin overproduction strains.
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Affiliation(s)
- Fan Xu
- School of Chemical Engineering, Hebei University of Technology, Tianjin 300131, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Chuan Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Miaomiao Xia
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Shixin Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- School of Biological Engineering, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Ran Tu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Sijia Wang
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Hongxing Jin
- School of Chemical Engineering, Hebei University of Technology, Tianjin 300131, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Böhning J, Ghrayeb M, Pedebos C, Abbas DK, Khalid S, Chai L, Bharat TAM. Donor-strand exchange drives assembly of the TasA scaffold in Bacillus subtilis biofilms. Nat Commun 2022; 13:7082. [PMID: 36400765 PMCID: PMC9674648 DOI: 10.1038/s41467-022-34700-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022] Open
Abstract
Many bacteria in nature exist in multicellular communities termed biofilms, where cells are embedded in an extracellular matrix that provides rigidity to the biofilm and protects cells from chemical and mechanical stresses. In the Gram-positive model bacterium Bacillus subtilis, TasA is the major protein component of the biofilm matrix, where it has been reported to form functional amyloid fibres contributing to biofilm structure and stability. Here, we present electron cryomicroscopy structures of TasA fibres, which show that, rather than forming amyloid fibrils, TasA monomers assemble into fibres through donor-strand exchange, with each subunit donating a β-strand to complete the fold of the next subunit along the fibre. Combining electron cryotomography, atomic force microscopy, and mutational studies, we show how TasA fibres congregate in three dimensions to form abundant fibre bundles that are essential for B. subtilis biofilm formation. Our study explains the previously observed biochemical properties of TasA and shows how a bacterial extracellular globular protein can assemble from monomers into β-sheet-rich fibres, and how such fibres assemble into bundles in biofilms.
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Affiliation(s)
- Jan Böhning
- grid.4991.50000 0004 1936 8948Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE UK
| | - Mnar Ghrayeb
- grid.9619.70000 0004 1937 0538Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 91904 Israel ,grid.9619.70000 0004 1937 0538The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 91904 Israel
| | - Conrado Pedebos
- grid.4991.50000 0004 1936 8948Department of Biochemistry, University of Oxford, Oxford, OX1 3QU UK
| | - Daniel K. Abbas
- grid.4991.50000 0004 1936 8948Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE UK
| | - Syma Khalid
- grid.4991.50000 0004 1936 8948Department of Biochemistry, University of Oxford, Oxford, OX1 3QU UK
| | - Liraz Chai
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 91904, Israel. .,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem, 91904, Israel.
| | - Tanmay A. M. Bharat
- grid.4991.50000 0004 1936 8948Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE UK ,grid.42475.300000 0004 0605 769XStructural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH UK
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12
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Kong L, Huang Y, Zeng X, Ye C, Wu Z, Guo Y, Pan D. Effects of galactosyltransferase on EPS biosynthesis and freeze-drying resistance of Lactobacillus acidophilus NCFM. FOOD CHEMISTRY. MOLECULAR SCIENCES 2022; 5:100145. [PMID: 36573108 PMCID: PMC9789326 DOI: 10.1016/j.fochms.2022.100145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/01/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022]
Abstract
Galactosyltransferase (GalT) is an important enzyme in synthesizing exopolysaccharide (EPS), the major polymer of biofilms protecting cells from severe conditions. However, the contribution to, and regulatory mechanism of GalT, in stressor resistance are still unclear. Herein, we successfully overexpressed GalT in Lactobacillus acidophilus NCFM by genetic engineering. The GalT activity and freeze-drying survival rate of the recombinant strain were significantly enhanced. The EPS yield also increased by 17.8%, indicating a positive relationship between freeze-drying resistance and EPS. RNA-Seq revealed that GalT could regulate the flux of the membrane transport system, pivotal sugar-related metabolic pathways, and promote quorum sensing to facilitate EPS biosynthesis, which enhanced freeze-drying resistance. The findings concretely prove that the mechanism of GalT regulating EPS biosynthesis plays an important role in protecting lactic acid bacteria from freeze-drying stress.
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Key Words
- BP, biological process
- CC, cellular component
- DEG, differentially expressed gene
- ELISA, enzyme linked immunosorbent assay
- EPS, exopolysaccharideS
- Exopolysaccharide
- FT-IR, Fourier transform infrared spectroscopy
- Freeze-drying
- GO, gene ontology
- GalT, galactosyltransferase
- Galactosyltransferase
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- LAB, lactic acid bacteria
- LB, Luria-Bertani
- MF, molecular function
- MRS, de Man, Rogosa and Sharpe
- NCBI, National Center for Biotechnology Information GenBank
- Overexpression
- PCR, polymerase chain reaction
- PEP, phosphoenolpyruvate
- PTS, phosphotransferase system
- QS, quorum sensing
- RT-qPCR, real-time quantitative polymerase chain reaction
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Affiliation(s)
- Lingyu Kong
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Yuze Huang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Xiaoqun Zeng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China,Corresponding author at: State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China.
| | - Congyan Ye
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Zhen Wu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Yuxing Guo
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210097, China
| | - Daodong Pan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo 315211, China,Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
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13
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Sadiq FA, Wenwei L, Wei C, Jianxin Z, Zhang H. Transcriptional Changes in Bifidobacterium bifidum Involved in Synergistic Multispecies Biofilms. MICROBIAL ECOLOGY 2022; 84:922-934. [PMID: 34676439 DOI: 10.1007/s00248-021-01904-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Bifidobacterium bifidum is part of the core microbiota of healthy infant guts where it may form biofilms on epithelial cells, mucosa, and food particles in the gut lumen. Little is known about transcriptional changes in B. bifidum engaged in synergistic multispecies biofilms with ecologically relevant species of the human gut. Recently, we reported prevalence of synergism in mixed-species biofilms formed by the human gut microbiota. This study represents a comparative gene expression analysis of B. bifidum when grown in a single-species biofilm and in two multispecies biofilm consortia with Bifidobacterium longum subsp. infantis, Bacteroides ovatus, and Parabacteroides distasonis in order to identify genes involved in this adaptive process in mixed biofilms and the influence on its metabolic and functional traits. Changes up to 58% and 43% in its genome were found when it grew in three- and four-species biofilm consortia, respectively. Upregulation of genes of B. bifidum involved in carbohydrate metabolism (particularly the galE gene), quorum sensing (luxS and pfs), and amino acid metabolism (especially branched chain amino acids) in both multispecies biofilms, compared to single-species biofilms, suggest that they may be contributing factors for the observed synergistic biofilm production when B. bifidum coexists with other species in a biofilm.
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Affiliation(s)
- Faizan Ahmed Sadiq
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Lu Wenwei
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Chen Wei
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122, China
| | - Zhao Jianxin
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122, China.
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14
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Transcriptome Analyses of Prophage in Mediating Persistent Methicillin-Resistant Staphylococcus aureus Endovascular Infection. Genes (Basel) 2022; 13:genes13091527. [PMID: 36140695 PMCID: PMC9498598 DOI: 10.3390/genes13091527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 12/24/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a significant subset of S. aureus infections and correlate with exceptionally high mortality. We have recently demonstrated that the lysogenization of prophage ϕSA169 from a clinical persistent MRSA bacteremia isolate (300-169) into a clinical resolving bacteremia MRSA isolate (301-188) resulted in the acquisition of well-defined in vitro and in vivo phenotypic and genotypic profiles related to persistent outcome. However, the underlying mechanism(s) of this impact is unknown. In the current study, we explored the genetic mechanism that may contribute to the ϕSA169-correlated persistence using RNA sequencing. Transcriptomic analyses revealed that the most significant impacts of ϕSA169 were: (i) the enhancement of fatty acid biosynthesis and purine and pyrimidine metabolic pathways; (ii) the repression of galactose metabolism and phosphotransferase system (PTS); and (iii) the down-regulation of the mutual prophage genes in both 300-169 and 301-188 strains. In addition, the influence of different genetic backgrounds between 300-169 and 301-188 might also be involved in the persistent outcome. These findings may provide targets for future studies on the persistence of MRSA.
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15
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Kong L, Xiong Z, Song X, Xia Y, Ai L. CRISPR/dCas9-based metabolic pathway engineering for the systematic optimization of exopolysaccharide biosynthesis in Streptococcus thermophilus. J Dairy Sci 2022; 105:6499-6512. [PMID: 35691751 DOI: 10.3168/jds.2021-21409] [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: 10/11/2021] [Accepted: 01/05/2022] [Indexed: 12/23/2022]
Abstract
Streptococcus thermophilus is used extensively in the dairy industry and has shown great promise as a chassis cell for the biosynthesis of high-value metabolites. However, metabolic engineering in S. thermophilus lacks effective genetic modification tools to modulate gene expression to relieve metabolic burden and maximize the production of desired compounds. Here, we developed a clustered regularly interspaced short palindromic repeats interference (CRISPRi) system for efficient gene transcriptional modulation in S. thermophilus. Our CRISPRi system typically achieved 66 to 98% knockdown of single or multiple gene expression. We used CRISPRi for the biosynthesis of a new exopolysaccharide (EPS) as a paradigm model. Repression of galK at module of uridine diphosphate glucose sugar metabolism and overexpression of epsA and epsE at EPS synthesis module resulted in an approximately 2-fold increase in EPS titer (277 mg/L) when compared with a control strain. This study demonstrated the effectiveness of CRISPRi as a powerful metabolic engineering tool and synthetic biology strategy for S. thermophilus.
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Affiliation(s)
- Linghui Kong
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; School of Pharmacy (School of Enology), Binzhou Medical University, Yantai, 264003, Shandong Province, China
| | - Zhiqiang Xiong
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Xin Song
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Yongjun Xia
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Lianzhong Ai
- Shanghai Engineering Research Center of Food Microbiology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
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16
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Prebiotic Isomaltooligosaccharide Provides an Advantageous Fitness to the Probiotic Bacillus subtilis CU1. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12136404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bacillus subtilis CU1 is a probiotic strain with beneficial effects on immune health in elderly subjects and diarrhea. Commercialized under spore form, new strategies to improve the germination, fitness and beneficial effects of the probiotic once in the gut have to be explored. For this purpose, functional food ingredients, such as isomaltooligosaccharides (IMOSs), could improve the fitness of Bacillus probiotics. IMOSs are composed of α(1 → 6)- and α(1 → 4)-linked oligosaccharides and are partially indigestible. Dietary IMOSs stimulate beneficial members of intestinal microbiota, but the effect of a combination of IMOSs with probiotics, such as B. subtilis CU1, is unknown. In this study, we evaluate the potential effect of IMOSs in B. subtilis CU1 and identify the metabolic pathways involved. The biochemical analysis of the commercial IMOSs highlights a degree of polymerization (DP) comprised between 1 and 29. The metabolism of IMOSs in CU1 was attributed to an α-glucosidase, secreted in the extracellular compartment one hundred times more than with glucose, and which seems to hydrolyze high DP IMOSs into shorter oligosaccharides (DP1, DP2 and DP3) in the culture medium. Proteomic analysis of CU1 after growth on IMOSs showed a reshaping of B. subtilis CU1 metabolism and functions, associated with a decreased production of lactic acid and acetic acid by two times. Moreover, we show for the first time that IMOSs could improve the germination of a Bacillus probiotic in the presence of bile salts in vitro, with an 8 h reduced lag-time when compared to a glucose substrate. Moreover, bacterial concentration (CFU/mL) was increased by about 1 log in IMOS liquid cultures after 48 h when compared to glucose. In conclusion, the use of IMOSs in association with probiotic B. subtilis CU1 in a synbiotic product could improve the fitness and benefits of the probiotic.
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17
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Zhang J, Zhu B, Li X, Xu X, Li D, Zeng F, Zhou C, Liu Y, Li Y, Lu F. Multiple Modular Engineering of Bacillus Amyloliquefaciens Cell Factories for Enhanced Production of Alkaline Proteases From B. Clausii. Front Bioeng Biotechnol 2022; 10:866066. [PMID: 35497355 PMCID: PMC9046661 DOI: 10.3389/fbioe.2022.866066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Bacillus amyloliquefaciens is a generally recognized as safe (GRAS) microorganism that presents great potential for the production of heterologous proteins. In this study, we performed genomic and comparative transcriptome to investigate the critical modular in B. amyloliquefaciens on the production of heterologous alkaline proteases (AprE). After investigation, it was concluded that the key modules affecting the production of alkaline protease were the sporulation germination module (Module I), extracellular protease synthesis module (Module II), and extracellular polysaccharide synthesis module (Module III) in B. amyloliquefaciens. In Module I, AprE yield for mutant BA ΔsigF was 25.3% greater than that of BA Δupp. Combining Module I synergistically with mutation of extracellular proteases in Module II significantly increased AprE production by 36.1% compared with production by BA Δupp. In Module III, the mutation of genes controlling extracellular polysaccharides reduced the viscosity and the accumulation of sediment, and increased the rate of dissolved oxygen in fermentation. Moreover, AprE production was 39.6% higher than in BA Δupp when Modules I, II and III were engineered in combination. This study provides modular engineering strategies for the modification of B. amyloliquefaciens for the production of alkaline proteases.
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Affiliation(s)
- Jinfang Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Baoyue Zhu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xinyue Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xiaojian Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Dengke Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Fang Zeng
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Cuixia Zhou
- School of Biology and Brewing Engineering, Taishan University, Taian, China
| | - Yihan Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Yu Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, the College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
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Yang X, Lai JL, Zhang Y, Luo XG. Reshaping the microenvironment and bacterial community of TNT- and RDX-contaminated soil by combined remediation with vetiver grass (Vetiveria ziznioides) and effective microorganism (EM) flora. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152856. [PMID: 34998745 DOI: 10.1016/j.scitotenv.2021.152856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/26/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Explosive pollutants remaining in global soils are serious threats to human health and ecological safety. Soils contaminated by trinitrotoluene (TNT) and cyclotrimethylene trinitramine (RDX) are simulated in this study and remediated using vetiver grass and effective microorganism (EM) flora to determine the efficacy of combined remediation in reshaping the microenvironment and bacterial community of soils contaminated by explosives. The degradation rates of TNT and RDX after 60 days of combined remediation were 95.66% and 84.37%, respectively. Soil microbial activity and enzyme activities related to the nitrogen cycle were upregulated. The content of soil elements in the remediation group changed significantly. Vetiver remediation increased the diversity and significantly changed the structure of the microbial community. Notably, bacteria, such as Sphingomonadaceae and Actinobacteriota, which can degrade explosives, occupied the soil niche, and the Proteobacteria and Bacteroidota, which are involved in sugar metabolism, showed particularly increased abundance. The metabolism of soil carbohydrates, fatty acids, and amino acids was upregulated in the vetiver, EM flora, and combined vetiver+EM flora remediation groups, and the most significantly upregulated pathway was galactose metabolism. The combined vetiver and EM flora treatment of soil contaminated by explosives greatly improved the ecology of the soil microenvironment.
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Affiliation(s)
- Xu Yang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Jin-Long Lai
- College of Environment and Resources, Southwest University of Science and Technology, Mianyang 621010, China; State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
| | - Yu Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
| | - Xue-Gang Luo
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
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19
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Ivo Ganchev. Role of Multispecies Biofilms with a Dominance of Bacillus subtilis in the Rhizosphere. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021150061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Pathak R, Vergis J, Chouhan G, Kumar M, Malik SS, Barbuddhe SB, Rawool DB. Comparative efficiency of carbohydrates on the biofilm‐forming ability of enteroaggregative
Escherichia coli. J Food Saf 2022. [DOI: 10.1111/jfs.12971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Richa Pathak
- Division of Veterinary Public Health ICAR‐Indian Veterinary Research Institute Bareilly Uttar Pradesh India
- Department of Biotechnology, School of Engineering and Technology Sharda University Greater Noida Uttar Pradesh India
| | - Jess Vergis
- Division of Veterinary Public Health ICAR‐Indian Veterinary Research Institute Bareilly Uttar Pradesh India
| | - Garima Chouhan
- Department of Biotechnology, School of Engineering and Technology Sharda University Greater Noida Uttar Pradesh India
| | - Manesh Kumar
- Division of Veterinary Public Health ICAR‐Indian Veterinary Research Institute Bareilly Uttar Pradesh India
| | - Satyaveer Singh Malik
- Division of Veterinary Public Health ICAR‐Indian Veterinary Research Institute Bareilly Uttar Pradesh India
| | | | - Deepak Bhiwa Rawool
- Division of Veterinary Public Health ICAR‐Indian Veterinary Research Institute Bareilly Uttar Pradesh India
- ICAR‐National Research Centre on Meat Chengicherla Telangana India
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21
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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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22
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Xiong Z, Zheng J, Sun H, Hu J, Sheng X, He L. Biofilm-overproducing Bacillus amyloliquefaciens P29ΔsinR decreases Pb availability and uptake in lettuce in Pb-polluted soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114016. [PMID: 34717106 DOI: 10.1016/j.jenvman.2021.114016] [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: 08/17/2021] [Revised: 09/30/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
In this study, one mutant strain P29ΔsinR with increased biofilm production was constructed from a biofilm-producing Bacillus amyloliquefaciens strain P29. Then, the effect of strain P29 and its biofilm-overproducing mutant strain P29ΔsinR on Pb availability and accumulation in lettuce and the associated mechanisms were characterized in the Pb-contaminated soil. The live strains P29 and P29ΔsinR increased the dry masses of roots and edible tissues by 31-74% compared to the controls. The live strains P29 and P29ΔsinR reduced the Pb uptake in the roots by 36-52% and edible tissues by 24-43%, Pb bioconcentration factor by 36-52%, and rhizosphere soil available Pb content by 12-25%, respectively, compared to the controls. The live strains P29 and P29ΔsinR increased the pH, proportion of biofilm-producing bacteria by 46-154%, contents of polysaccharides by 99-139% and proteins by 32-57%, and gene relative abundances of epsC by 7.1-10.2-fold, tasA by 10.3-10.8-fold, and sipW by 6.5-26.1-fold, which were associated with biofilm formation and Pb adsorption in the rhizosphere soils, respectively, compared to the controls. Furthermore, the mutant strain P29ΔsinR showed higher ability to reduce Pb availability and uptake in lettuce and increase the pH, proportion of biofilm-producing bacteria, polysaccharide and protein contents, and relative abundances of these genes. These results showed that the biofilm-overproducing strain P29ΔsinR induced lower Pb availability and accumulation in the vegetable and more biofilm-producing bacteria, polysaccharide and protein production, and Pb-immobilizing related gene abundances in the Pb-contaminated soil.
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Affiliation(s)
- ZhiHui Xiong
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China
| | - JinWei Zheng
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China
| | - HaiRong Sun
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China
| | - JingWen Hu
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China
| | - XiaFang Sheng
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China.
| | - LinYan He
- College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture, Nanjing, 210095, PR China.
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Kawakami M, Matsuoka S. Galactolipids from <i>Arabidopsis thaliana</i> can replace the function of gluco lipids in <i>Bacillus subtilis</i>. J GEN APPL MICROBIOL 2022; 68:54-61. [DOI: 10.2323/jgam.2021.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Manami Kawakami
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Satoshi Matsuoka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
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24
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Dynamic tracing of bacterial community distribution and biofilm control of dominant species in milk powder processing. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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25
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Stavridou E, Giannakis I, Karamichali I, Kamou NN, Lagiotis G, Madesis P, Emmanouil C, Kungolos A, Nianiou-Obeidat I, Lagopodi AL. Biosolid-Amended Soil Enhances Defense Responses in Tomato Based on Metagenomic Profile and Expression of Pathogenesis-Related Genes. PLANTS (BASEL, SWITZERLAND) 2021; 10:2789. [PMID: 34961260 PMCID: PMC8709368 DOI: 10.3390/plants10122789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/12/2021] [Accepted: 12/13/2021] [Indexed: 05/28/2023]
Abstract
Biosolid application is an effective strategy, alternative to synthetic chemicals, for enhancing plant growth and performance and improving soil properties. In previous research, biosolid application has shown promising results with respect to tomato resistance against Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Herein, we aimed at elucidating the effect of biosolid application on the plant-microbiome response mechanisms for tomato resistance against Forl at a molecular level. More specifically, plant-microbiome interactions in the presence of biosolid application and the biocontrol mechanism against Forl in tomato were investigated. We examined whether biosolids application in vitro could act as an inhibitor of growth and sporulation of Forl. The effect of biosolid application on the biocontrol of Forl was investigated based on the enhanced plant resistance, measured as expression of pathogen-response genes, and pathogen suppression in the context of soil microbiome diversity, abundance, and predicted functions. The expression of the pathogen-response genes was variably induced in tomato plants in different time points between 12 and 72 h post inoculation in the biosolid-enriched treatments, in the presence or absence of pathogens, indicating activation of defense responses in the plant. This further suggests that biosolid application resulted in a successful priming of tomato plants inducing resistance mechanisms against Forl. Our results have also demonstrated that biosolid application alters microbial diversity and the predicted soil functioning, along with the relative abundance of specific phyla and classes, as a proxy for disease suppression. Overall, the use of biosolid as a sustainable soil amendment had positive effects not only on plant health and protection, but also on growth of non-pathogenic antagonistic microorganisms against Forl in the tomato rhizosphere and thus, on plant-soil microbiome interactions, toward biocontrol of Forl.
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Affiliation(s)
- Evangelia Stavridou
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece; (E.S.); (I.K.); (G.L.); (P.M.)
- Laboratory of Genetics and Plant Breeding, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Ioannis Giannakis
- School of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.G.); (A.K.)
| | - Ioanna Karamichali
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece; (E.S.); (I.K.); (G.L.); (P.M.)
| | - Nathalie N. Kamou
- Laboratory of Plant Pathology, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - George Lagiotis
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece; (E.S.); (I.K.); (G.L.); (P.M.)
| | - Panagiotis Madesis
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece; (E.S.); (I.K.); (G.L.); (P.M.)
- Laboratory of Molecular Biology of Plants, School of Agricultural Sciences, University of Thessaly, 38221 Volos, Greece
| | - Christina Emmanouil
- School of Spatial Planning and Development, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Athanasios Kungolos
- School of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (I.G.); (A.K.)
| | - Irini Nianiou-Obeidat
- Laboratory of Genetics and Plant Breeding, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Anastasia L. Lagopodi
- Laboratory of Plant Pathology, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
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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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Sharma SR, Crispell G, Mohamed A, Cox C, Lange J, Choudhary S, Commins SP, Karim S. Alpha-Gal Syndrome: Involvement of Amblyomma americanum α-D-Galactosidase and β-1,4 Galactosyltransferase Enzymes in α-Gal Metabolism. Front Cell Infect Microbiol 2021; 11:775371. [PMID: 34926322 PMCID: PMC8671611 DOI: 10.3389/fcimb.2021.775371] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Alpha-Gal Syndrome (AGS) is an IgE-mediated delayed-type hypersensitivity reaction to the oligosaccharide galactose-α-1, 3-galactose (α-gal) injected into humans from the lone-star tick (Amblyomma americanum) bite. Indeed, α-gal is discovered in salivary glands of lone-star tick; however, the tick's specific intrinsic factors involved in endogenous α-gal production and presentation to host during hematophagy are poorly understood. This study aimed to investigate the functional role of two tick enzymes, α-D-galactosidase (ADGal) and β-1,4 galactosyltransferases (β-1,4GalT), in endogenous α-gal production, carbohydrate metabolism, and N-glycan profile in lone-star tick. The ADGal enzyme cleaves terminal α-galactose moieties from glycoproteins and glycolipids, whereas β-1,4GalT transfers α-galactose to a β1,4 terminal linkage acceptor sugars-GlcNAc, Glc, and Xyl-in various processes of glycoconjugate synthesis. An RNA interference approach was utilized to silence ADGal and β-1,4GalT in Am. americanum to examine their function in α-gal metabolism in tick and AGS onset. Silencing of ADGal led to the significant downregulation of genes involved in galactose metabolism and transport in Am. americanum. Immunoblot and N-glycan analysis of the Am. americanum salivary glands showed a significant reduction in α-gal levels in silenced tissues. However, there was no significant difference in the level of α-gal in β-1,4GalT-silenced tick salivary glands. A basophil-activation test showed a decrease in the frequency of activated basophil by ADGal-silenced salivary glands. These results provide an insight into the roles of ADGal and β-1,4GalT in α-gal production and presentation in ticks and the probable involvement in the onset of AGS.
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Affiliation(s)
- Surendra Raj Sharma
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Gary Crispell
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Ahmed Mohamed
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Cameron Cox
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Joshua Lange
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Shailesh Choudhary
- Department of Medicine and Pediatrics, University of North Carolina, Chapel Hill, NC, United States
| | - Scott P. Commins
- Department of Medicine and Pediatrics, University of North Carolina, Chapel Hill, NC, United States
| | - Shahid Karim
- School of Biological, Environment and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
- Center for Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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Li J, Yang X, Lai JL, Zhang Y, Luo XG, Zhao SP, Zhu YB. Characteristics of RDX degradation and the mechanism of the RDX exposure response in a Klebsiella sp. strain. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Patel N, Curtis JC, Plotkin BJ. Insulin Regulation of Escherichia coli Abiotic Biofilm Formation: Effect of Nutrients and Growth Conditions. Antibiotics (Basel) 2021; 10:antibiotics10111349. [PMID: 34827287 PMCID: PMC8615133 DOI: 10.3390/antibiotics10111349] [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: 09/15/2021] [Revised: 10/21/2021] [Accepted: 11/02/2021] [Indexed: 11/23/2022] Open
Abstract
Escherichia coli plays an important role in biofilm formation across a wide array of disease and ecological settings. Insulin can function as an adjuvant in the regulation of biofilm levels. The modulation of insulin-regulated biofilm formation by environmental conditions has not been previously described. In the present study, the effects that various environmental growth conditions and nutrients have on insulin-modulated levels of biofilm production were measured. Micropipette tips were incubated with E. coli ATCC® 25922™ in a Mueller Hinton broth (MH), or a yeast nitrogen base with 1% peptone (YNBP), which was supplemented with glucose, lactose, galactose and/or insulin (Humulin®-R). The incubation conditions included a shaking or static culture, at 23 °C or 37 °C. After incubation, the biofilm production was calculated per CFU. At 23 °C, the presence of insulin increased biofilm formation. The amount of biofilm formation was highest in glucose > galactose >> lactose, while the biofilm levels decreased in shaking cultures, except for galactose (3-fold increase; 0.1% galactose and 20 μU insulin). At 37 °C, regardless of condition, there was more biofilm formation/CFU under static conditions in YNBP than in MH, except for the MH containing galactose. E. coli biofilm formation is influenced by aeration, temperature, and insulin concentration in combination with the available sugars.
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Affiliation(s)
- Nina Patel
- Department of Microbiology and Immunology, College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (N.P.); (J.C.C.)
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60625, USA
| | - Jeremy C. Curtis
- Department of Microbiology and Immunology, College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (N.P.); (J.C.C.)
| | - Balbina J. Plotkin
- Department of Microbiology and Immunology, College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (N.P.); (J.C.C.)
- Correspondence:
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Arnaouteli S, Bamford NC, Stanley-Wall NR, Kovács ÁT. Bacillus subtilis biofilm formation and social interactions. Nat Rev Microbiol 2021; 19:600-614. [PMID: 33824496 DOI: 10.1038/s41579-021-00540-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2021] [Indexed: 02/03/2023]
Abstract
Biofilm formation is a process in which microbial cells aggregate to form collectives that are embedded in a self-produced extracellular matrix. Bacillus subtilis is a Gram-positive bacterium that is used to dissect the mechanisms controlling matrix production and the subsequent transition from a motile planktonic cell state to a sessile biofilm state. The collective nature of life in a biofilm allows emergent properties to manifest, and B. subtilis biofilms are linked with novel industrial uses as well as probiotic and biocontrol processes. In this Review, we outline the molecular details of the biofilm matrix and the regulatory pathways and external factors that control its production. We explore the beneficial outcomes associated with biofilms. Finally, we highlight major advances in our understanding of concepts of microbial evolution and community behaviour that have resulted from studies of the innate heterogeneity of biofilms.
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Affiliation(s)
- Sofia Arnaouteli
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Natalie C Bamford
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Nicola R Stanley-Wall
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK.
| | - Ákos T Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kongens Lyngby, Denmark.
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Genome Mining Associated with Analysis of Structure, Antioxidant Activity Reveals the Potential Production of Levan-Rich Exopolysaccharides by Food-Derived Bacillus velezensis VTX20. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11157055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Exopolysaccharides (EPSs) produced by Bacillus species have recently emerged as promising commercial antioxidants in various industries, such as pharmaceutics and biomedicine. However, little is known about EPS production and function from Bacillus velezensis so far. In the present study, the effect of sugar sources on EPS production by B. velezensis VTX20 and the genetic biosynthesis, characteristics, and antioxidant activity of the resulting EPS were evaluated. The strain VTX20 produced the maximum EPS yield of 75.5 ± 4.8 g/L from an initial 200 g/L of sucrose after a 48-h cultivation. Through genomic analysis, ls-levB operon was found, for the first time, to be responsible for the levan-type EPS production in B. velezensis. Biochemical and structural characterization further confirmed the majority of levan, followed by an extremely low level of dextran biopolymer. The water solubility index and water holding capacity of the EPSs were 81.9 ± 3.4% and 100.2 ± 3.4%, respectively. In vitro antioxidant activity analyses showed strong scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical values of 40.1–64.0% and 16.0–40%, respectively. These findings shed light on the EPS biosynthesis of B. velezensis at both structural and genetic levels and the potential application of EPS as a natural antioxidant for pharmaceutical and biomedical industries.
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Mohsin MZ, Omer R, Huang J, Mohsin A, Guo M, Qian J, Zhuang Y. Advances in engineered Bacillus subtilis biofilms and spores, and their applications in bioremediation, biocatalysis, and biomaterials. Synth Syst Biotechnol 2021; 6:180-191. [PMID: 34401544 PMCID: PMC8332661 DOI: 10.1016/j.synbio.2021.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 06/24/2021] [Accepted: 07/23/2021] [Indexed: 01/23/2023] Open
Abstract
Bacillus subtilis is a commonly used commercial specie with broad applications in the fields of bioengineering and biotechnology. B. subtilis is capable of producing both biofilms and spores. Biofilms are matrix-encased multicellular communities that comprise various components including exopolysaccharides, proteins, extracellular DNA, and poly-γ-glutamic acid. These biofilms resist environmental conditions such as oxidative stress and hence have applications in bioremediation technologies. Furthermore, biofilms and spores can be engineered through biotechnological techniques for environmentally-friendly and safe production of bio-products such as enzymes. The ability to withstand with harsh conditions and producing spores makes Bacillus a suitable candidate for surface display technology. In recent years, the spores of such specie are widely used as it is generally regarded as safe to use. Advances in synthetic biology have enabled the reprogramming of biofilms to improve their functions and enhance the production of value-added products. Globally, there is increased interest in the production of engineered biosensors, biocatalysts, and biomaterials. The elastic modulus and gel properties of B. subtilis biofilms have been utilized to develop living materials. This review outlines the formation of B. subtilis biofilms and spores. Biotechnological engineering processes and their increasing application in bioremediation and biocatalysis, as well as the future directions of B. subtilis biofilm engineering, are discussed. Furthermore, the ability of B. subtilis biofilms and spores to fabricate functional living materials with self-regenerating, self-regulating and environmentally responsive characteristics has been summarized. This review aims to resume advances in biological engineering of B. subtilis biofilms and spores and their applications.
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Key Words
- Bacillus subtilis
- Biocatalysis
- Biofilms
- Biomaterials
- Bioremediation
- Extracellular DNA, (eDNA)
- Extracellular Polymeric Substance/ Exopolysaccharide, (EPS)
- Gold nanoparticles, (AuNPs)
- Green fluorescent protein, (GFP)
- Isopropylthio-β-d-galactoside, (IPTG)
- Menaquinoe-7, (MK-7)
- Microbial fuel cell, (MFC)
- Mono (2-hydroxyethyl) terephthalic acid, (MHET)
- N-Acetyl-d-neuraminic Acid, (Neu5Ac)
- N-acetylglucosamine, (GlcNAc)
- Nanoparticles, (NPs)
- Nickel nitriloacetic acid, (Ni-NTA)
- Organophosphorus hydrolase, (OPH)
- Paranitrophenol, (PNP)
- Paraoxon, (PAR)
- Quantum dots, (QDs)
- Spores
- Synthetic biology
- d-psicose 3-epimerase, (DPEase)
- l-Arabinose Isomerase, (L-AI)
- p-aminophenol, (PAP)
- β-Galactosidase, (β-Gal)
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Affiliation(s)
- Muhammad Zubair Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Rabia Omer
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Jiaofang Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Ali Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Meijin Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Jiangchao Qian
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Yingping Zhuang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China
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Sharipova MR, Mardanova AM, Rudakova NL, Pudova DS. Bistability and Formation of the Biofilm Matrix as Adaptive Mechanisms during the Stationary Phase of Bacillus subtilis. Microbiology (Reading) 2021. [DOI: 10.1134/s002626172006017x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Investigation of the Physiology of the Obligate Alkaliphilic Bacillus marmarensis GMBE 72 T Considering Its Alkaline Adaptation Mechanism for Poly(3-hydroxybutyrate) Synthesis. Microorganisms 2021; 9:microorganisms9020462. [PMID: 33672214 PMCID: PMC7926669 DOI: 10.3390/microorganisms9020462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 11/25/2022] Open
Abstract
The novel extreme obligate alkaliphilic Bacillus marmarensis DSM 21297 is known to produce polyhydroxybutyrate (PHB). However, the detailed mechanism of PHB synthesis in B. marmarensis is still unknown. Here, we investigated which metabolic pathways and metabolic enzymes are responsible for PHB synthesis in order to understand the regulatory pathway and optimize PHB synthesis in B. marmarensis. In accordance with the fact that beta-galactosidase, 3-hydroxyacyl-CoA dehydrogenase, and Enoyl-CoA hydratase together with acyl-CoA dehydrogenase and lipase were annotated in B. marmarensis according to the RAST server, we used glucose, lactose, and olive oil to understand the preferred metabolic pathway for the PHB synthesis. It was found that B. marmarensis produces PHB from glucose, lactose, and olive oil. However, the highest PHB titer and the highest amount of PHB synthesized per dry cell mass (YP/X) were achieved in the presence of lactose, as compared to glucose and olive oil. Additionally, in the absence of peptone, the amount of PHB synthesized is reduced for each carbon source. Interestingly, none of the carbon sources studied yielded an efficient PHB synthesis, and supplementation of the medium with potassium ions did not enhance PHB synthesis. According to these experimental results and the presence of annotated metabolic enzymes based on the RAST server, PHB accumulation in the cells of B. marmarensis could be improved by the level of the expression of 3-hydroxybutyryl-CoA dehydrogenase (1.1.1.157), which increases the production of NADPH. Additionally, the accumulation of 3-hydroxyacyl-CoA could enhance the production of PHB in B. marmarensis in the presence of fatty acids. To our knowledge, this is the first report investigating the regulatory system involved in the control of PHB metabolism of B. marmarensis.
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Bharti S, Maurya RK, Venugopal U, Singh R, Akhtar MS, Krishnan MY. Rv1717 Is a Cell Wall - Associated β-Galactosidase of Mycobacterium tuberculosis That Is Involved in Biofilm Dispersion. Front Microbiol 2021; 11:611122. [PMID: 33584576 PMCID: PMC7873859 DOI: 10.3389/fmicb.2020.611122] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/16/2020] [Indexed: 01/12/2023] Open
Abstract
Understanding the function of conserved hypothetical protein (CHP)s expressed by a pathogen in the infected host can lead to better understanding of its pathogenesis. The present work describes the functional characterization of a CHP, Rv1717 of Mycobacterium tuberculosis (Mtb). Rv1717 has been previously reported to be upregulated in TB patient lungs. Rv1717 belongs to the cupin superfamily of functionally diverse proteins, several of them being carbohydrate handling proteins. Bioinformatic analysis of the amino acid sequence revealed similarity to glycosyl hydrolases. Enzymatic studies with recombinant Rv1717 purified from Escherichia coli showed that the protein is a β-D-galactosidase specific for pyranose form rather than the furanose form. We expressed the protein in Mycobacterium smegmatis (Msm), which lacks its ortholog. In MsmRv1717, the protein was found to localize to the cell wall (CW) with a preference to the poles. MsmRv1717 showed significant changes in colony morphology and cell surface properties. Most striking observation was its unusual Congo red colony morphotype, reduced ability to form biofilms, pellicles and autoagglutinate. Exogenous Rv1717 not only prevented biofilm formation in Msm, but also degraded preformed biofilms, suggesting that its substrate likely exists in the exopolysaccharides of the biofilm matrix. Presence of galactose in the extracellular polymeric substance (EPS) has not been reported before and hence we used the galactose-specific Wisteria floribunda lectin (WFL) to test the same. The lectin extensively bound to Msm and Mtb EPS, but not the bacterium per se. Purified Rv1717 also hydrolyzed exopolysaccharides extracted from Msm biofilm. Eventually, to decipher its role in Mtb, we downregulated its expression and demonstrate that the strain is unable to disperse from in vitro biofilms, unlike the wild type. Biofilms exposed to carbon starvation showed a sudden upregulation of Rv1717 transcripts supporting the potential role of Rv1717 in Mtb dispersing from a deteriorating biofilm.
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Affiliation(s)
- Suman Bharti
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Rahul Kumar Maurya
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | | | - Radhika Singh
- Toxicology and Health Risk Assessment Division, CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Md Sohail Akhtar
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow, India
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de Sá MCA, da Silva WM, Rodrigues CCS, Rezende CP, Marchioro SB, Rocha Filho JTR, Sousa TDJ, de Oliveira HP, da Costa MM, Figueiredo HCP, Portela RD, Castro TLDP, Azevedo V, Seyffert N, Meyer R. Comparative Proteomic Analyses Between Biofilm-Forming and Non-biofilm-Forming Strains of Co rynebacterium pseudotuberculosis Isolated From Goats. Front Vet Sci 2021; 8:614011. [PMID: 33665217 PMCID: PMC7921313 DOI: 10.3389/fvets.2021.614011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/21/2021] [Indexed: 11/20/2022] Open
Abstract
Caseous lymphadenitis (CLA) is a chronic disease that affects small ruminants and causes economic losses in the associated breeding system. The causative agent of CLA is Corynebacterium pseudotuberculosis, a Gram-positive bacterium that exhibits tropism for external and internal lymph nodes and induces abscess formation in the host. Bacterial communities often produce a biofilm matrix that serves various functions, including protection against hostile environmental conditions, antibiotics, and the host immune response. Although biofilm formation has been reported for C. pseudotuberculosis, not all strains demonstrate this property in culture. In this work, we report the first comparative proteomic analysis of one biofilm-forming (CAPJ4) and one biofilm-non-forming strain (CAP3W) of C. pseudotuberculosis isolated from goats. Bacterial whole cell protein extracts were obtained for mass spectrometry analyses. Using LC-MS/MS, our studies reveal three and four proteins exclusively found in the CAPJ4 and CAP3W proteome, respectively. In addition, label-free quantitative analysis identified 40 proteins showing at-least 2-fold higher values in CAPJ4 compared CAP3W proteome Notably, CAPJ4 differentially synthesized the penicillin-binding protein, which participates in the formation of peptidoglycans. CAPJ4 also exhibited upregulation of N-acetylmuramoyl-L-alanine amidase and galactose-1-phosphate uridylyltransferase, which are involved in biofilm formation and exopolysaccharide biosynthesis. Here, we demonstrate that biofilm formation in C. pseudotuberculosis is likely associated with specific proteins, some of which were previously shown to be associated with virulence and biofilm formation in other organisms. Our findings may drive studies related to the bacterial mechanisms involved in the biofilm formation, in addition to providing targets for the treatment of CLA.
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Affiliation(s)
| | - Wanderson Marques da Silva
- Instituto de Agrobiotecnología y Biologia Molecular Instituto Nacional de Tecnología Agropecuária/Consejo Nacional de Investigaciones Científicas y Técnicas (IABIMO-INTA/CONICET), Buenos Aires, Argentina
| | | | | | | | | | - Thiago de Jesus Sousa
- Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | | | - Vasco Azevedo
- Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Nubia Seyffert
- Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil
| | - Roberto Meyer
- Institute of Health Sciences, Federal University of Bahia, Salvador, Brazil
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Integrated meta-analysis and machine learning approach identifies acyl-CoA thioesterase with other novel genes responsible for biofilm development in Staphylococcus aureus. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2021; 88:104702. [PMID: 33388440 DOI: 10.1016/j.meegid.2020.104702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 12/24/2020] [Accepted: 12/29/2020] [Indexed: 02/08/2023]
Abstract
Biofilm forming Staphylococcus aureus is a major threat to the health-care industry. It is important to understand the differences between planktonic and biofilm growth forms in the pathogen since conventional treatments targeting the planktonic forms are not effective against biofilms. The current study conducts a meta-analysis of three public transcriptomic profiles to examine the differences in gene expression between the planktonic and biofilm states of S. aureus using random-effects modeling. Mean effect sizes were calculated for 2847 genes among which 726 differentially expressed genes were taken for further analysis. Major genes that are discriminatory between the two conditions were mined using supervised learning techniques and validated by high-accuracy classifiers. Ten different feature selection algorithms were applied and used to rank the most important genes in S. aureus biofilms. Finally, an optimal set of 36 genes are presented as candidate genes in biofilm formation or development while throwing light on the novel roles of an acyl-CoA thioesterase enzyme and 10 hypothetical proteins in biofilms. The relevance of the identified gene set was further validated by building five different classification models using SVM, RF, kNN, NB and DT algorithms that were compared with models built from other relevant gene sets and by reviewing the functional role of 25 previously known genes in biofilm development. The study combines meta-analysis of differential expression with supervised machine learning strategies and feature selection for the first time to identify and validate a discriminatory set of genes important in biofilms of S. aureus. The functional roles of the identified genes predicted to be important in biofilms are further scrutinized and can be considered as a signature target list to develop anti-biofilm therapeutics in S. aureus.
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Abstract
While there has been much study of bacterial gene dispensability, there is a lack of comprehensive genome-scale examinations of the impact of gene deletion on growth in different carbon sources. In this context, a lot can be learned from such experiments in the model microbe Escherichia coli where much is already understood and there are existing tools for the investigation of carbon metabolism and physiology (1). Gene deletion studies have practical potential in the field of antibiotic drug discovery where there is emerging interest in bacterial central metabolism as a target for new antibiotics (2). Furthermore, some carbon utilization pathways have been shown to be critical for initiating and maintaining infection for certain pathogens and sites of infection (3–5). Here, with the use of high-throughput solid medium phenotyping methods, we have generated kinetic growth measurements for 3,796 genes under 30 different carbon source conditions. This data set provides a foundation for research that will improve our understanding of genes with unknown function, aid in predicting potential antibiotic targets, validate and advance metabolic models, and help to develop our understanding of E. coli metabolism. Central metabolism is a topic that has been studied for decades, and yet, this process is still not fully understood in Escherichia coli, perhaps the most amenable and well-studied model organism in biology. To further our understanding, we used a high-throughput method to measure the growth kinetics of each of 3,796 E. coli single-gene deletion mutants in 30 different carbon sources. In total, there were 342 genes (9.01%) encompassing a breadth of biological functions that showed a growth phenotype on at least 1 carbon source, demonstrating that carbon metabolism is closely linked to a large number of processes in the cell. We identified 74 genes that showed low growth in 90% of conditions, defining a set of genes which are essential in nutrient-limited media, regardless of the carbon source. The data are compiled into a Web application, Carbon Phenotype Explorer (CarPE), to facilitate easy visualization of growth curves for each mutant strain in each carbon source. Our experimental data matched closely with the predictions from the EcoCyc metabolic model which uses flux balance analysis to predict growth phenotypes. From our comparisons to the model, we found that, unexpectedly, phosphoenolpyruvate carboxylase (ppc) was required for robust growth in most carbon sources other than most trichloroacetic acid (TCA) cycle intermediates. We also identified 51 poorly annotated genes that showed a low growth phenotype in at least 1 carbon source, which allowed us to form hypotheses about the functions of these genes. From this list, we further characterized the ydhC gene and demonstrated its role in adenosine efflux.
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Panichikkal J, Edayileveetil Krishnankutty R. Rhizobacterial biofilm and plant growth promoting trait enhancement by organic acids and sugars. BIOFOULING 2020; 36:990-999. [PMID: 33148046 DOI: 10.1080/08927014.2020.1832219] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
In the study,Pseudomonas sp. K6 and Pseudomonas monteilii were found to form an enhanced biofilm when cultured in the presence of organic acids and sugars. Here, the highest biofilm could be observed for Pseudomonas sp. K6 (3.08 ± 0.13) and P. monteilii (1.99 ± 0.12) when cultured in presence of 10 µM malic acid. However, maximum production of indole 3 acetic acid (IAA) was observed with 25 µM succinic acid treatment for Pseudomonas sp. K6 (24.33 ± 0.57 µg ml-1) and with 25 µM galactose for P. monteilii (20 ± 0.0 µg ml-1). At the same time, Pseudomonas sp. K6 solubilized the highest quantity of phosphate in the presence of 50 µM citric acid (21.33 ± 0.0 µM) and P. monteilii was observed to produce 32.66 ± 1.25 µM soluble phosphate in the presence of 10 µM galactose. The results of the study demonstrate the role of organic acids and sugars in the enhancement of biofilm formation, IAA production and phosphate solubilization in selected Pseudomonas spp. and highlight the potential use of rhizobacteria in conjugation with supplement for the agricultural applications.
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Affiliation(s)
- Jishma Panichikkal
- School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India
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40
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Wang Y, Cong S, Zhang Q, Li R, Wang K. iTRAQ-Based Proteomics Reveals Potential Anti-Virulence Targets for ESBL-Producing Klebsiella pneumoniae. Infect Drug Resist 2020; 13:2891-2899. [PMID: 32903891 PMCID: PMC7445504 DOI: 10.2147/idr.s259894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/28/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose Treatment of infections with Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases (ESBLs) is challenging due to the coexistence of multiple resistance mechanisms and the hypervirulent variant. Therefore, new targets or more effective treatment options aimed at ESBL-producing Klebsiella pneumoniae are urgently needed. Materials and Methods Here, we collected ESBL-producing and non-ESBL Klebsiella pneumoniae isolates and studied their differences from a proteomic point of view. Results We revealed treA, wza, gnd, rmlA, rmlC, rmlD, galE, aceE, and sucD as important virulence-related proteins in ESBL-producing Klebsiella pneumoniae, distinct from those in non-ESBL strains. Conclusion Our findings provide plausible anti-virulence targets and suggest new therapeutic avenues against ESBL-producing Klebsiella pneumoniae.
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Affiliation(s)
- Yan Wang
- Department of Respiratory and Critical Care Medicine., The Second Hospital of Jilin University, Changchun, People's Republic of China
| | - Shan Cong
- Department of Respiratory and Critical Care Medicine., The Second Hospital of Jilin University, Changchun, People's Republic of China
| | - Qinghua Zhang
- Department of Respiratory and Critical Care Medicine., The Second Hospital of Jilin University, Changchun, People's Republic of China
| | - Ranwei Li
- Department of Urology, The Second Hospital of Jilin University, Changchun, People's Republic of China
| | - Ke Wang
- Department of Respiratory and Critical Care Medicine., The Second Hospital of Jilin University, Changchun, People's Republic of China
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Ido N, Lybman A, Hayet S, Azulay DN, Ghrayeb M, Liddawieh S, Chai L. Bacillus subtilis biofilms characterized as hydrogels. Insights on water uptake and water binding in biofilms. SOFT MATTER 2020; 16:6180-6190. [PMID: 32567645 DOI: 10.1039/d0sm00581a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Biofilms are aggregates of cells that form on surfaces or at the air-water interface. Cells in a biofilm are encased in a self-secreted extracellular matrix (ECM) that provides them with mechanical stability and protects them from antibiotic treatment. From a soft matter perspective, biofilms are regarded as colloidal hydrogels, with the cells playing the role of colloids and the ECM compared with a cross-linked hydrogel. Here, we examined whole biofilms of the soil bacterium Bacillus subtilis utilizing methods that are commonly used to characterize hydrogels in order to evaluate the uptake of water and the water properties in the biofilms. Specifically, we studied wild-type as well ECM mutants, lacking the protein TasA and the exopolysaccharide (EPS). We characterized the morphology and mesh size of biofilms using electron microscopy, studied the state of water in the biofilms using differential scanning calorimetry, and finally, we tested the biofilms' swelling properties. Our study revealed that Bacillus subtilis biofilms resemble cross-linked hydrogels in their morphology and swelling properties. Strikingly, we discovered that all the water in biofilms was bound water and there was no free water in the biofilms. Water binding was mostly related with the presence of solutes and much less so with the major ECM components, the protein TasA and the polysaccharide EPS. This study sheds light on water uptake and water binding in biofilms and it is therefore important for the understanding of solute transport and enzymatic function inside biofilms.
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Affiliation(s)
- Nir Ido
- The Israel Institute for Biological Research, Ness Ziona, Israel
| | - Amir Lybman
- The Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shahar Hayet
- Institute of Chemistry, The Hebrew University of Jerusalem and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, Jerusalem 91904, Israel.
| | - David N Azulay
- Institute of Chemistry, The Hebrew University of Jerusalem and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, Jerusalem 91904, Israel.
| | - Mnar Ghrayeb
- Institute of Chemistry, The Hebrew University of Jerusalem and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, Jerusalem 91904, Israel.
| | - Sajeda Liddawieh
- Institute of Chemistry, The Hebrew University of Jerusalem and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, Jerusalem 91904, Israel.
| | - Liraz Chai
- Institute of Chemistry, The Hebrew University of Jerusalem and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, Jerusalem 91904, Israel.
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42
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Soni A, Oey I, Silcock P, Ross IK, Bremer PJ. Effect of pulsed electric field with moderate heat (80°C) on inactivation, thermal resistance and differential gene expression in B. cereusspores. J FOOD PROCESS PRES 2020. [DOI: 10.1111/jfpp.14503] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Aswathi Soni
- Department of Food Science University of Otago Dunedin New Zealand
- AgResearch Palmerston North New Zealand
| | - Indrawati Oey
- Department of Food Science University of Otago Dunedin New Zealand
- Riddet Institute Palmerston North New Zealand
| | - Patrick Silcock
- Department of Food Science University of Otago Dunedin New Zealand
| | - Ian K. Ross
- Department of Food Science University of Otago Dunedin New Zealand
| | - Phil J. Bremer
- Department of Food Science University of Otago Dunedin New Zealand
- New Zealand Food Safety Science Research Centre Palmerston North New Zealand
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Steinberg N, Keren-Paz A, Hou Q, Doron S, Yanuka-Golub K, Olender T, Hadar R, Rosenberg G, Jain R, Cámara-Almirón J, Romero D, van Teeffelen S, Kolodkin-Gal I. The extracellular matrix protein TasA is a developmental cue that maintains a motile subpopulation within Bacillus subtilis biofilms. Sci Signal 2020; 13:13/632/eaaw8905. [PMID: 32430292 DOI: 10.1126/scisignal.aaw8905] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In nature, bacteria form biofilms-differentiated multicellular communities attached to surfaces. Within these generally sessile biofilms, a subset of cells continues to express motility genes. We found that this subpopulation enabled Bacillus subtilis biofilms to expand on high-friction surfaces. The extracellular matrix (ECM) protein TasA was required for the expression of flagellar genes. In addition to its structural role as an adhesive fiber for cell attachment, TasA acted as a developmental signal stimulating a subset of biofilm cells to revert to a motile phenotype. Transcriptomic analysis revealed that TasA stimulated the expression of a specific subset of genes whose products promote motility and repress ECM production. Spontaneous suppressor mutations that restored motility in the absence of TasA revealed that activation of the biofilm-motility switch by the two-component system CssR/CssS antagonized the TasA-mediated reversion to motility in biofilm cells. Our results suggest that although mostly sessile, biofilms retain a degree of motility by actively maintaining a motile subpopulation.
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Affiliation(s)
- Nitai Steinberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.,Department of Microbiology, Institute Pasteur, Paris, France
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Qihui Hou
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Shany Doron
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Keren Yanuka-Golub
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tsviya Olender
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rotem Hadar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gili Rosenberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rakeshkumar Jain
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Jesus Cámara-Almirón
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Diego Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | | | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
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Keren-Paz A, Kolodkin-Gal I. A brick in the wall: Discovering a novel mineral component of the biofilm extracellular matrix. N Biotechnol 2020; 56:9-15. [DOI: 10.1016/j.nbt.2019.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/01/2019] [Accepted: 11/02/2019] [Indexed: 01/09/2023]
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45
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Di Rienzi SC, Britton RA. Adaptation of the Gut Microbiota to Modern Dietary Sugars and Sweeteners. Adv Nutr 2020; 11:616-629. [PMID: 31696209 PMCID: PMC7231582 DOI: 10.1093/advances/nmz118] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/15/2019] [Accepted: 10/03/2019] [Indexed: 02/07/2023] Open
Abstract
The consumption of sugar has become central to the Western diet. Cost and health concerns associated with sucrose spurred the development and consumption of other sugars and sweeteners, with the average American consuming 10 times more sugar than 100 y ago. In this review, we discuss how gut microbes are affected by changes in the consumption of sugars and other sweeteners through transcriptional, abundance, and genetic adaptations. We propose that these adaptations result in microbes taking on different metabolic, ecological, and genetic profiles along the intestinal tract. We suggest novel approaches to assess the consequences of these changes on host-microbe interactions to determine the safety of novel sugars and sweeteners.
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Affiliation(s)
- Sara C Di Rienzi
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Robert A Britton
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
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46
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Kretschmer M, Lieleg O. Chelate chemistry governs ion-specific stiffening of Bacillus subtilis B-1 and Azotobacter vinelandii biofilms. Biomater Sci 2020; 8:1923-1933. [PMID: 32031543 DOI: 10.1039/c9bm01763a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unwanted formation of bacterial biofilms can cause problems in both the medical sector and industrial settings. However, removing them from surfaces remains an ongoing challenge since biofilm bacteria efficiently protect themselves from external influences such as mechanical shear forces by embedding themselves into a matrix of extracellular polymeric substances. Here, we discuss microscopic principles, which are responsible for alterations in the viscoelastic properties of biofilms upon contact with metal ions. We suggest that it is a combination of mainly two parameters, that decides if biofilm stiffening occurs or not: the ion size and the detailed configuration of polyanionic macromolecules from the biofilm matrix. Our results provide new insights in the molecular mechanisms that govern the mechanical properties of biofilms. Also, they indicate that hydrogels comprising purified biopolymers can serve as suitable model systems to reproduce certain aspects of biofilm mechanics - provided that the correct biopolymer is chosen.
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Affiliation(s)
- Martin Kretschmer
- Munich School of Bioengineering and Department of Mechanical Engineering, Technical University of Munich, 85748 Garching, Germany.
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47
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Tian T, Reverdy A, She Q, Sun B, Chai Y. The role of rhizodeposits in shaping rhizomicrobiome. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:160-172. [PMID: 31858707 DOI: 10.1111/1758-2229.12816] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 05/22/2023]
Abstract
Rhizomicrobiome, the communities of microorganisms surrounding the root of the plant, plays a vital role in promoting plant growth and health. The composition of rhizomicrobiome is dynamic both temporally and spatially, and is influenced greatly by the plant host and environmental factors. One of the key influencing factors is rhizodeposits, composed of root-released tissue cells, exudates, lysates, volatile compounds, etc. Rhizodeposits are rich in carbon and nitrogen elements, and able to select and fuel the growth of rhizomicrobiome. In this minireview, we overview the generation, composition and dynamics of rhizodeposits, and discuss recent work describing the general and specific impacts of rhizodeposits on rhizomicrobiome. We focus further on root exudates, the most dynamic component of rhizodeposits, and review recent progresses about the influence of specific root exudates in promoting bacterial root colonization, inducing biofilm development, acting as plant defence and shaping the rhizomicrobiome.
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Affiliation(s)
- Tao Tian
- Tianjin Academy of Agricultural Sciences, Institute of Plant Protection, Tianjin, China
- Department of Biology, Northeastern University, Boston, MA, USA
| | - Alicyn Reverdy
- Department of Biology, Northeastern University, Boston, MA, USA
| | - Qianxuan She
- Department of Biology, Northeastern University, Boston, MA, USA
| | - Bingbing Sun
- Tianjin Academy of Agricultural Sciences, Institute of Plant Protection, Tianjin, China
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA, USA
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Eida AA, Bougouffa S, L’Haridon F, Alam I, Weisskopf L, Bajic VB, Saad MM, Hirt H. Genome Insights of the Plant-Growth Promoting Bacterium Cronobacter muytjensii JZ38 With Volatile-Mediated Antagonistic Activity Against Phytophthora infestans. Front Microbiol 2020; 11:369. [PMID: 32218777 PMCID: PMC7078163 DOI: 10.3389/fmicb.2020.00369] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/19/2020] [Indexed: 12/12/2022] Open
Abstract
Salinity stress is a major challenge to agricultural productivity and global food security in light of a dramatic increase of human population and climate change. Plant growth promoting bacteria can be used as an additional solution to traditional crop breeding and genetic engineering. In the present work, the induction of plant salt tolerance by the desert plant endophyte Cronobacter sp. JZ38 was examined on the model plant Arabidopsis thaliana using different inoculation methods. JZ38 promoted plant growth under salinity stress via contact and emission of volatile compounds. Based on the 16S rRNA and whole genome phylogenetic analysis, fatty acid analysis and phenotypic identification, JZ38 was identified as Cronobacter muytjensii and clearly separated and differentiated from the pathogenic C. sakazakii. Full genome sequencing showed that JZ38 is composed of one chromosome and two plasmids. Bioinformatic analysis and bioassays revealed that JZ38 can grow under a range of abiotic stresses. JZ38 interaction with plants is correlated with an extensive set of genes involved in chemotaxis and motility. The presence of genes for plant nutrient acquisition and phytohormone production could explain the ability of JZ38 to colonize plants and sustain plant growth under stress conditions. Gas chromatography-mass spectrometry analysis of volatiles produced by JZ38 revealed the emission of indole and different sulfur volatile compounds that may play a role in contactless plant growth promotion and antagonistic activity against pathogenic microbes. Indeed, JZ38 was able to inhibit the growth of two strains of the phytopathogenic oomycete Phytophthora infestans via volatile emission. Genetic, transcriptomic and metabolomics analyses, combined with more in vitro assays will provide a better understanding the highlighted genes' involvement in JZ38's functional potential and its interaction with plants. Nevertheless, these results provide insight into the bioactivity of C. muytjensii JZ38 as a multi-stress tolerance promoting bacterium with a potential use in agriculture.
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Affiliation(s)
- Abdul Aziz Eida
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Salim Bougouffa
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- BioScience Core Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | | | - Intikhab Alam
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Laure Weisskopf
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Vladimir B. Bajic
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Maged M. Saad
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Heribert Hirt
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
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49
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Caro-Astorga J, Álvarez-Mena A, Hierrezuelo J, Guadix JA, Heredia-Ponce Z, Arboleda-Estudillo Y, González-Munoz E, de Vicente A, Romero D. Two genomic regions encoding exopolysaccharide production systems have complementary functions in B. cereus multicellularity and host interaction. Sci Rep 2020; 10:1000. [PMID: 31969664 PMCID: PMC6976573 DOI: 10.1038/s41598-020-57970-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/09/2020] [Indexed: 01/10/2023] Open
Abstract
Bacterial physiology and adaptation are influenced by the exopolysaccharides (EPS) they produce. These polymers are indispensable for the assembly of the biofilm extracellular matrix in multiple bacterial species. In a previous study, we described the profound gene expression changes leading to biofilm assembly in B. cereus ATCC14579 (CECT148). We found that a genomic region putatively dedicated to the synthesis of a capsular polysaccharide (eps2) was overexpressed in a biofilm cell population compared to in a planktonic population, while we detected no change in the transcript abundance from another genomic region (eps1) also likely to be involved in polysaccharide production. Preliminary biofilm assays suggested a mild role for the products of the eps2 region in biofilm formation and no function for the products of the eps1 region. The aim of this work was to better define the roles of these two regions in B. cereus multicellularity. We demonstrate that the eps2 region is indeed involved in bacterial adhesion to surfaces, cell-to-cell interaction, cellular aggregation and biofilm formation, while the eps1 region appears to be involved in a kind of social bacterial motility. Consistent with these results, we further demonstrate using bacterial-host cell interaction experiments that the eps2 region is more relevant to the adhesion to human epithelial cells and the zebrafish intestine, suggesting that this region encodes a bacterial factor that may potentiate gut colonization and enhance pathogenicity against humans.
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Affiliation(s)
- Joaquin Caro-Astorga
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain
| | - Ana Álvarez-Mena
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain
| | - Jesús Hierrezuelo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain
| | - Juan Antonio Guadix
- Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga - IBIMA, Campus de Teatinos s/n, 29071, Málaga, Spain
- Centro Andaluz de Nanomedicina y Biotecnología (BIONAND), Junta de Andalucía, Universidad de Málaga, C/ Severo Ochoa 35, 29590, Campanillas (Málaga), Spain
| | - Zahira Heredia-Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain
| | - Yohanna Arboleda-Estudillo
- LARCEL, Andalusian Laboratory of Cell Reprogramming, Andalusian Center for Nanomedicine and Biotechnology-BIONAND, 29590, Málaga, Spain
| | - Elena González-Munoz
- LARCEL, Andalusian Laboratory of Cell Reprogramming, Andalusian Center for Nanomedicine and Biotechnology-BIONAND, 29590, Málaga, Spain
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain
| | - Diego Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" -Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de Teatinos), 29071, Málaga, Spain.
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Ahmed A, Narayanan RA, Veni AR. Influence of carbon source complexity on porosity, water retention and extracellular matrix composition of Neurospora discreta biofilms. J Appl Microbiol 2019; 128:1099-1108. [PMID: 31793753 DOI: 10.1111/jam.14539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/20/2019] [Accepted: 12/01/2019] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate carbon source complexity as a process lever to impact the microstructure, chemical composition and water retention capacity of biofilms produced by Neurospora discreta. METHODS AND RESULTS Biofilms were produced by nonpathogenic fungus N. discreta, using sucrose, cellulose or lignin as carbon source. The increase in complexity of carbon source from sucrose to lignin resulted in decreased water retention values (WRV) and wet weights of harvested biofilms. Confocal laser scanning microscopy was used to calculate porosity from bright-field images, and relative stained areas of cells and carbohydrates from fluorescence imaging of samples stained with Trypan blue and Alexa Fluor 488. Porosity and relative quantity of cells increased with increase in carbon source complexity while the amount of carbohydrates decreased. The chemical analysis of the extracted extracellular matrix (ECM) showed that biofilms grown on more complex carbon sources had lower carbohydrate and protein content, which also explains the lower WRV trend, as carbohydrates are hydrophilic. CONCLUSIONS The nature of carbon source impacts the metabolic pathway of cells, thereby influencing the relative proportions of ECM and cells. This in turn impacts the microstructure, composition and water content of biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY This work shows that carbon source can be used as process lever to control the properties of biofilms and presents a novel view of biofilms as potentially useful biomaterials.
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Affiliation(s)
- A Ahmed
- School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, UK
| | - R A Narayanan
- Department of Physics, Birla Institute of Technology and Science (Pilani), Hyderabad, India
| | - A R Veni
- Department of Chemical Engineering, Birla Institute of Technology and Science (Pilani), Hyderabad, India
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