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Li R, Yang P, Zhang H, Wang C, Zhao F, Liu J, Wang Y, Liang Y, Sun T, Xie X. Comparative Genomic and Functional Analysis of c-di-GMP Metabolism and Regulatory Proteins in Bacillus velezensis LQ-3. Microorganisms 2024; 12:1724. [PMID: 39203566 PMCID: PMC11357230 DOI: 10.3390/microorganisms12081724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Revised: 08/08/2024] [Accepted: 08/16/2024] [Indexed: 09/03/2024] Open
Abstract
Bacillus velezensis is a promising candidate for biocontrol applications. A common second messenger molecule, bis-(3,5)-cyclic-dimeric-guanosine monophosphate (c-di-GMP), has the ability to regulate a range of physiological functions that impact the effectiveness of biocontrol. However, the status of the c-di-GMP signaling pathway in biocontrol strain LQ-3 remains unknown. Strain LQ-3, which was isolated from wheat rhizosphere soil, has shown effective control of wheat sharp eyespot and has been identified as B. velezensis through whole-genome sequencing analyses. In this study, we investigated the intracellular c-di-GMP signaling pathway of LQ-3 and further performed a comparative genomic analysis of LQ-3 and 29 other B. velezensis strains. The results revealed the presence of four proteins containing the GGDEF domain, which is the conserved domain for c-di-GMP synthesis enzymes. Additionally, two proteins were identified with the EAL domain, which represents the conserved domain for c-di-GMP degradation enzymes. Furthermore, one protein was found to possess a PilZ domain, indicative of the conserved domain for c-di-GMP receptors in LQ-3. These proteins are called DgcK, DgcP, YybT, YdaK, PdeH, YkuI, and DgrA, respectively; they are distributed in a similar manner across the strains and belong to the signal transduction family. We selected five genes from the aforementioned seven genes for further study, excluding YybT and DgrA. They all play a role in regulating the motility, biofilm formation, and colonization of LQ-3. This study reveals the c-di-GMP signaling pathway associated with biocontrol features in B. velezensis LQ-3, providing guidance for the prevention and control of wheat sharp eyespot by LQ-3.
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Affiliation(s)
- Rong Li
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Panlei Yang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Hongjuan Zhang
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Chunjing Wang
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Fang Zhao
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Jiehui Liu
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Yanbin Wang
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Yan Liang
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Ting Sun
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
| | - Xiansheng Xie
- Institute of Wheat Research, Shanxi Agricultural University, Linfen 041000, China; (R.L.); (H.Z.); (C.W.); (F.Z.); (J.L.); (Y.W.); (Y.L.); (T.S.)
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Roncarati D, Vannini A, Scarlato V. Temperature sensing and virulence regulation in pathogenic bacteria. Trends Microbiol 2024:S0966-842X(24)00180-X. [PMID: 39164134 DOI: 10.1016/j.tim.2024.07.009] [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: 06/06/2024] [Revised: 07/16/2024] [Accepted: 07/23/2024] [Indexed: 08/22/2024]
Abstract
Pathogenic bacteria can detect a variety of environmental signals, including temperature changes. While sudden and significant temperature variations act as danger signals that trigger a protective heat-shock response, minor temperature fluctuations typically signal to the pathogen that it has moved from one environment to another, such as entering a specific niche within a host during infection. These latter temperature fluctuations are utilized by pathogens to coordinate the expression of crucial virulence factors. Here, we elucidate the critical role of temperature in governing the expression of virulence factors in bacterial pathogens. Moreover, we outline the molecular mechanisms used by pathogens to detect temperature fluctuations, focusing on systems that employ proteins and nucleic acids as sensory devices. We also discuss the potential implications and the extent of the risk that climate change poses to human pathogenic diseases.
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Affiliation(s)
- Davide Roncarati
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy.
| | - Andrea Vannini
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Bologna, Italy
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3
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Huang W, Wang D, Zhang XX, Zhao M, Sun L, Zhou Y, Guan X, Xie Z. Regulatory roles of the second messenger c-di-GMP in beneficial plant-bacteria interactions. Microbiol Res 2024; 285:127748. [PMID: 38735241 DOI: 10.1016/j.micres.2024.127748] [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: 10/11/2023] [Revised: 05/02/2024] [Accepted: 05/03/2024] [Indexed: 05/14/2024]
Abstract
The rhizosphere system of plants hosts a diverse consortium of bacteria that confer beneficial effects on plant, such as plant growth-promoting rhizobacteria (PGPR), biocontrol agents with disease-suppression activities, and symbiotic nitrogen fixing bacteria with the formation of root nodule. Efficient colonization in planta is of fundamental importance for promoting of these beneficial activities. However, the process of root colonization is complex, consisting of multiple stages, including chemotaxis, adhesion, aggregation, and biofilm formation. The secondary messenger, c-di-GMP (cyclic bis-(3'-5') dimeric guanosine monophosphate), plays a key regulatory role in a variety of physiological processes. This paper reviews recent progress on the actions of c-di-GMP in plant beneficial bacteria, with a specific focus on its role in chemotaxis, biofilm formation, and nodulation.
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Affiliation(s)
- Weiwei Huang
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Dandan Wang
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Xue-Xian Zhang
- School of Natural Sciences, Massey University at Albany, Auckland 0745, New Zealand
| | - Mengguang Zhao
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Li Sun
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Yanan Zhou
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Xin Guan
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China
| | - Zhihong Xie
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong Province 271018, China.
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Liu L, Luo D, Zhang Y, Liu D, Yin K, Tang Q, Chou SH, He J. Characterization of the dual regulation by a c-di-GMP riboswitch Bc1 with a long expression platform from Bacillus thuringiensis. Microbiol Spectr 2024; 12:e0045024. [PMID: 38819160 PMCID: PMC11218506 DOI: 10.1128/spectrum.00450-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/29/2024] [Indexed: 06/01/2024] Open
Abstract
A riboswitch generally regulates the expression of its downstream genes through conformational change in its expression platform (EP) upon ligand binding. The cyclic diguanosine monophosphate (c-di-GMP) class I riboswitch Bc1 is widespread and conserved among Bacillus cereus group species. In this study, we revealed that Bc1 has a long EP with two typical ρ-independent terminator sequences 28 bp apart. The upstream terminator T1 is dominant in vitro, while downstream terminator T2 is more efficient in vivo. Through mutation analysis, we elucidated that Bc1 exerts a rare and incoherent "transcription-translation" dual regulation with T2 playing a crucial role. However, we found that Bc1 did not respond to c-di-GMP under in vitro transcription conditions, and the expressions of downstream genes did not change with fluctuation in intracellular c-di-GMP concentration. To explore this puzzle, we conducted SHAPE-MaP and confirmed the interaction of Bc1 with c-di-GMP. This shows that as c-di-GMP concentration increases, T1 unfolds but T2 remains almost intact and functional. The presence of T2 masks the effect of T1 unwinding, resulting in no response of Bc1 to c-di-GMP. The high Shannon entropy values of EP region imply the potential alternative structures of Bc1. We also found that zinc uptake regulator can specifically bind to the dual terminator coding sequence and slightly trigger the response of Bc1 to c-di-GMP. This work will shed light on the dual-regulation riboswitch and enrich our understanding of the RNA world.IMPORTANCEIn nature, riboswitches are involved in a variety of metabolic regulation, most of which preferentially regulate transcription termination or translation initiation of downstream genes in specific ways. Alternatively, the same or different riboswitches can exist in tandem to enhance regulatory effects or respond to multiple ligands. However, many putative conserved riboswitches have not yet been experimentally validated. Here, we found that the c-di-GMP riboswitch Bc1 with a long EP could form a dual terminator and exhibit non-canonical and incoherent "transcription-translation" dual regulation. Besides, zinc uptake regulator specifically bound to the coding sequence of the Bc1 EP and slightly mediated the action of Bc1. The application of SHAPE-MaP to the dual regulation mechanism of Bc1 may establish the foundation for future studies of such complex untranslated regions in other bacterial genomes.
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Affiliation(s)
- Lu Liu
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Dehua Luo
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yongji Zhang
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Dingqi Liu
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Kang Yin
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Qing Tang
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shan-Ho Chou
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jin He
- National Key Laboratory of Agricultural Microbiology & Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Shao L, Shen Z, Li M, Guan C, Fan B, Chai Y, Zhao Y. ccdC Regulates Biofilm Dispersal in Bacillus velezensis FZB42. Int J Mol Sci 2024; 25:5201. [PMID: 38791239 PMCID: PMC11120784 DOI: 10.3390/ijms25105201] [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: 03/14/2024] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Bacillus velezensis FZB42 is a plant growth-promoting rhizobacterium (PGPR) and a model microorganism for biofilm studies. Biofilms are required for the colonization and promotion of plant growth in the rhizosphere. However, little is known about how the final stage of the biofilm life cycle is regulated, when cells regain their motility and escape the mature biofilm to spread and colonize new niches. In this study, the non-annotated gene ccdC was found to be involved in the process of biofilm dispersion. We found that the ccdC-deficient strain maintained a wrinkled state at the late stage of biofilm formation in the liquid-gas interface culture, and the bottom solution showed a clear state, indicating that no bacterial cells actively escaped, which was further evidenced by the formation of a cellular ring (biofilm pellicle) located on top of the preformed biofilm. It can be concluded that dispersal, a biofilm property that relies on motility proficiency, is also positively affected by the unannotated gene ccdC. Furthermore, we found that the level of cyclic diguanylate (c-di-GMP) in the ccdC-deficient strain was significantly greater than that in the wild-type strain, suggesting that B. velezensis exhibits a similar mechanism by regulating the level of c-di-GMP, the master regulator of biofilm formation, dispersal, and cell motility, which controls the fitness of biofilms in Pseudomonas aeruginosain. In this study, we investigated the mechanism regulating biofilm dispersion in PGPR.
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Affiliation(s)
- Lin Shao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grass, Nanjing Forestry University, Nanjing 210037, China
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China
| | - Zizhu Shen
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China
| | - Meiju Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grass, Nanjing Forestry University, Nanjing 210037, China
| | - Chenyun Guan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grass, Nanjing Forestry University, Nanjing 210037, China
| | - Ben Fan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grass, Nanjing Forestry University, Nanjing 210037, China
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - Yinjuan Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grass, Nanjing Forestry University, Nanjing 210037, China
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6
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Yu Z, Zhang W, Yang H, Chou SH, Galperin MY, He J. Gas and light: triggers of c-di-GMP-mediated regulation. FEMS Microbiol Rev 2023; 47:fuad034. [PMID: 37339911 PMCID: PMC10505747 DOI: 10.1093/femsre/fuad034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/01/2023] [Accepted: 06/17/2023] [Indexed: 06/22/2023] Open
Abstract
The widespread bacterial second messenger c-di-GMP is responsible for regulating many important physiological functions such as biofilm formation, motility, cell differentiation, and virulence. The synthesis and degradation of c-di-GMP in bacterial cells depend, respectively, on diguanylate cyclases and c-di-GMP-specific phosphodiesterases. Since c-di-GMP metabolic enzymes (CMEs) are often fused to sensory domains, their activities are likely controlled by environmental signals, thereby altering cellular c-di-GMP levels and regulating bacterial adaptive behaviors. Previous studies on c-di-GMP-mediated regulation mainly focused on downstream signaling pathways, including the identification of CMEs, cellular c-di-GMP receptors, and c-di-GMP-regulated processes. The mechanisms of CME regulation by upstream signaling modules received less attention, resulting in a limited understanding of the c-di-GMP regulatory networks. We review here the diversity of sensory domains related to bacterial CME regulation. We specifically discuss those domains that are capable of sensing gaseous or light signals and the mechanisms they use for regulating cellular c-di-GMP levels. It is hoped that this review would help refine the complete c-di-GMP regulatory networks and improve our understanding of bacterial behaviors in changing environments. In practical terms, this may eventually provide a way to control c-di-GMP-mediated bacterial biofilm formation and pathogenesis in general.
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Affiliation(s)
- Zhaoqing Yu
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
- Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing, Jiangsu 210014, PR China
| | - Wei Zhang
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - He Yang
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - Shan-Ho Chou
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Jin He
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
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Teethaisong Y, Chueakwon P, Poolpol K, Ayamuang IO, Suknasang S, Apinundecha C, Eumkeb G. Stephania suberosa Forman extract synergistically inhibits ampicillin- and vancomycin-resistant Enterococcus faecium. Saudi J Biol Sci 2023; 30:103557. [PMID: 36712182 PMCID: PMC9876979 DOI: 10.1016/j.sjbs.2023.103557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/07/2022] [Accepted: 01/08/2023] [Indexed: 01/19/2023] Open
Abstract
Increasing antibiotic resistance in enterococci is among the most serious public health problems worldwide. The new naturally occurring antibacterial agents were explored. This study, therefore, investigated the antibacterial potential of Stephania suberosa extract (SSE) and its synergism with ampicillin (AMP) or vancomycin (VAN) against AMP- and VAN-resistant Enterococcus faecium. Disc diffusion assay revealed that SSE inhibited E. faecium DMST 12829, 12852, 12970, and a reference strain of Enterococcus faecalis ATCC 29,212 in a dose-dependent manner. The minimum inhibitory concentration (MIC) of SSE against all E. faecium isolates was 0.5 mg/mL. E. faecium DMST 12,829 and 12,852 were highly resistant to AMP, as indicated by high MIC values, and E. faecium DMST 12,829 and 12,970 were resistant to VAN. Enterococcus spp. were killed by SSE at the minimum bactericidal concentrations (MBCs) ranging from 0.5 to 4 mg/mL. Checkerboard determination showed that SSE plus AMP and SSE plus VAN combinations exhibited synergistic interaction against E. faecium isolates. The killing curve assay of E. faecium isolates confirmed the antibacterial and synergistic activities of combined agents by dramatically reducing the viable counts compared to a single agent. Scanning electron microscope elucidated the cell damage and abnormal cell division. Enterococcal proteases were also inhibited by SSE. These findings support that SSE could reverse the activity of AMP and VAN. Moreover, it can synergistically inhibit AMP- and VAN-resistant E. faecium. Our combined agents could be attractive candidates for developing new combinatorial agents to resurrect the efficacy of antibiotics for treating AMP- and VAN-resistant E. faecium infections.
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Affiliation(s)
- Yothin Teethaisong
- Department of Medical Sciences, Faculty of Allied Health Sciences, Burapha University, Chon Buri 20131, Thailand,Research Unit for Sensor Innovation (RUSI), Burapha University, Chon Buri 20131, Thailand
| | - Piyasiri Chueakwon
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Kulwara Poolpol
- Department of Medical Sciences, Faculty of Allied Health Sciences, Burapha University, Chon Buri 20131, Thailand
| | - Intu-orn Ayamuang
- School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Siriporn Suknasang
- School of Preclinical Sciences, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Chittadech Apinundecha
- School of Preclinical Sciences, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Griangsak Eumkeb
- School of Preclinical Sciences, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand,Corresponding author.
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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: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [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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Affiliation(s)
- Yicen Lin
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Ákos T. Kovács
- Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, 2800, Lyngby, Denmark
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9
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Yu Z, Fu Y, Zhang W, Zhu L, Yin W, Chou SH, He J. The RNA Chaperone Protein Hfq Regulates the Characteristic Sporulation and Insecticidal Activity of Bacillus thuringiensis. Front Microbiol 2022; 13:884528. [PMID: 35479624 PMCID: PMC9037596 DOI: 10.3389/fmicb.2022.884528] [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: 02/26/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Bacillus thuringiensis (Bt) is one of the most widely used bio-insecticides at present. It can produce many virulence factors and insecticidal crystal proteins during growth and sporulation. Hfq, on the other hand, is a bacterial RNA chaperone that can regulate the function of different kinds of RNAs, thereby affecting various bacterial phenotypes. To further explore the physiological functions of Hfq in Bt, we took BMB171 as the starting strain, knocked out one, two, or three hfq genes in its genome in different combinations, and compared the phenotypic differences between the deletion mutant strains and the starting strain. We did observe significant changes in several phenotypes, including motility, biofilm formation, sporulation, and insecticidal activity against cotton bollworm, among others. Afterward, we found through transcriptome studies that when all hfq genes were deleted, 32.5% of the genes in Bt were differentially transcribed, with particular changes in the sporulation-related and virulence-related genes. The above data demonstrated that Hfq plays a pivotal role in Bt and can regulate its various physiological functions. Our study on the regulatory mechanism of Hfq in Bt, especially the mining of the regulatory network of its sporulation and insecticidal activity, could lay a theoretical foundation for the better utilization of Bt as an effective insecticide.
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Affiliation(s)
- Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yang Fu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,National Engineering Research Center of Edible Fungi, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Wei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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10
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Spore-Associated Proteins Involved in c-di-GMP Synthesis and Degradation of Bacillus anthracis. J Bacteriol 2021; 203:e0013521. [PMID: 34096779 DOI: 10.1128/jb.00135-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Bis-(3'-5')-cyclic-dimeric GMP (c-di-GMP) is an important bacterial regulatory signaling molecule affecting biofilm formation, toxin production, motility, and virulence. The genome of Bacillus anthracis, the causative agent of anthrax, is predicted to encode ten putative GGDEF/EAL/HD-GYP-domain containing proteins. Heterologous expression in Bacillus subtilis hosts indicated that there are five active GGDEF domain-containing proteins and four active EAL or HD-GYP domain-containing proteins. Using an mCherry gene fusion-Western blotting approach, the expression of the c-di-GMP-associated proteins was observed throughout the in vitro life cycle. Of the six c-di-GMP-associated proteins found to be present in sporulating cells, four (CdgA, CdgB, CdgD, and CdgG) contain active GGDEF domains. The six proteins expressed in sporulating cells are retained in spores in a CotE-independent manner and thus are not likely to be localized to the exosporium layer of the spores. Individual deletion mutations involving the nine GGDEF/EAL protein-encoding genes and one HD-GYP protein-encoding gene did not affect sporulation efficiency, the attachment of the exosporium glycoprotein BclA, or biofilm production. Notably, expression of anthrax toxin was not affected by deletion of any of the cdg determinants. Three determinants encoding proteins with active GGDEF domains were found to affect germination kinetics. This study reveals a spore association of cyclic-di-GMP regulatory proteins and a likely role for these proteins in the biology of the B. anthracis spore. IMPORTANCE The genus Bacillus is composed of Gram-positive, rod shaped, soil-dwelling bacteria. As a mechanism for survival in the harsh conditions in soil, the organisms undergo sporulation, and the resulting spores permit the organisms to survive harsh environmental conditions. Although most species are saprophytes, Bacillus cereus and Bacillus anthracis are human pathogens and Bacillus thuringiensis is an insect pathogen. The bacterial c-di-GMP regulatory system is an important control system affecting motility, biofilm formation, and toxin production. The role of c-di-GMP has been studied in the spore-forming bacilli Bacillus subtilis, Bacillus amyloliquefaciens, B. cereus, and B. thuringiensis. However, this regulatory system has not heretofore been examined in the high-consequence zoonotic pathogen of this genus, B. anthracis.
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11
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Xuan TF, Wang ZQ, Liu J, Yu HT, Lin QW, Chen WM, Lin J. Design and Synthesis of Novel c-di-GMP G-Quadruplex Inducers as Bacterial Biofilm Inhibitors. J Med Chem 2021; 64:11074-11089. [PMID: 34323486 DOI: 10.1021/acs.jmedchem.1c00465] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The formation of biofilms by clinical pathogens typically leads to chronic and recurring antibiotic-resistant infections. High cellular levels of cyclic diguanylate (c-di-GMP), a ubiquitous secondary messenger of bacteria, have been proven to be associated with a sessile biofilm lifestyle of pathogens. A promising antibiofilm strategy involving the induction of c-di-GMP to form dysfunctional G-quadruplexes, thereby blocking the c-di-GMP-mediated biofilm regulatory pathway, was proposed in this study. In this new strategy, a series of novel c-di-GMP G-quadruplex inducers were designed and synthesized for development of therapeutic biofilm inhibitors. Compound 5h exhibited favorable c-di-GMP G-quadruplex-inducing activity and 62.18 ± 6.76% biofilm inhibitory activity at 1.25 μM without any DNA intercalation effect. Moreover, the favorable performance of 5h in interfering with c-di-GMP-related biological functions, including bacterial motility and bacterial extracellular polysaccharide secretion, combined with the reporter strain and transcriptome analysis results confirmed the c-di-GMP signaling-related action mechanism of 5h.
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Affiliation(s)
- Teng-Fei Xuan
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Zi-Qiang Wang
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Jun Liu
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Hai-Tao Yu
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Qian-Wen Lin
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Wei-Min Chen
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
| | - Jing Lin
- College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China
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Fu Y, Yu Z, Zhu L, Li Z, Yin W, Shang X, Chou SH, Tan Q, He J. The Multiple Regulatory Relationship Between RNA-Chaperone Hfq and the Second Messenger c-di-GMP. Front Microbiol 2021; 12:689619. [PMID: 34335515 PMCID: PMC8323549 DOI: 10.3389/fmicb.2021.689619] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/18/2021] [Indexed: 11/25/2022] Open
Abstract
RNA chaperone protein Hfq is an important post-transcriptional regulator in bacteria, while c-di-GMP is a second messenger signaling molecule widely distributed in bacteria. Both factors have been found to play key roles in post-transcriptional regulation and signal transduction pathways, respectively. Intriguingly, the two factors show some common aspects in the regulation of certain physiological functions such as bacterial motility, biofilm formation, pathogenicity and so on. Therefore, there may be regulatory relationship between Hfq and c-di-GMP. For example, Hfq can directly regulate the activity of c-di-GMP metabolic enzymes or alter the c-di-GMP level through other systems, while c-di-GMP can indirectly enhance or inhibit the hfq gene expression through intermediate factors. In this article, after briefly introducing the Hfq and c-di-GMP regulatory systems, we will focus on the direct and indirect regulation reported between Hfq and c-di-GMP, aiming to compare and link the two regulatory systems to further study the complicated physiological and metabolic systems of bacteria, and to lay a solid foundation for drawing a more complete global regulatory network.
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Affiliation(s)
- Yang Fu
- National Engineering Research Center of Edible Fungi, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China.,State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhou Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiaodong Shang
- National Engineering Research Center of Edible Fungi, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Qi Tan
- National Engineering Research Center of Edible Fungi, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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13
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Bacterial Flagellar Filament: A Supramolecular Multifunctional Nanostructure. Int J Mol Sci 2021; 22:ijms22147521. [PMID: 34299141 PMCID: PMC8306008 DOI: 10.3390/ijms22147521] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/06/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023] Open
Abstract
The bacterial flagellum is a complex and dynamic nanomachine that propels bacteria through liquids. It consists of a basal body, a hook, and a long filament. The flagellar filament is composed of thousands of copies of the protein flagellin (FliC) arranged helically and ending with a filament cap composed of an oligomer of the protein FliD. The overall structure of the filament core is preserved across bacterial species, while the outer domains exhibit high variability, and in some cases are even completely absent. Flagellar assembly is a complex and energetically costly process triggered by environmental stimuli and, accordingly, highly regulated on transcriptional, translational and post-translational levels. Apart from its role in locomotion, the filament is critically important in several other aspects of bacterial survival, reproduction and pathogenicity, such as adhesion to surfaces, secretion of virulence factors and formation of biofilms. Additionally, due to its ability to provoke potent immune responses, flagellins have a role as adjuvants in vaccine development. In this review, we summarize the latest knowledge on the structure of flagellins, capping proteins and filaments, as well as their regulation and role during the colonization and infection of the host.
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14
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CdgL is a degenerate nucleotide cyclase domain protein affecting flagellin synthesis and motility in Bacillus thuringiensis. Res Microbiol 2021; 172:103850. [PMID: 34082027 DOI: 10.1016/j.resmic.2021.103850] [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: 10/02/2020] [Revised: 02/28/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022]
Abstract
In Bacillus subtilis, motility genes are expressed in a hierarchical pattern - governed by the σD transcription factor and other proteins such as the EpsE molecular clutch and SlrA/SlrR regulator proteins. In contrast, motile species in the Bacillus cereus group seem to express their motility genes in a non-hierarchical pattern, and less is known about their regulation, also given that no orthologs to σD, EpsE, SlrA or SlrR are found in B. cereus group genomes. Here we show that deletion of cdgL (BTB_RS26690/BTB_c54300) in Bacillus thuringiensis 407 (cry-) resulted in a six-to ten-fold downregulation of the entire motility locus, and loss of flagellar structures and swimming motility. cdgL is unique to the B. cereus group and is found in all phylogenetic clusters in the population except for group I, which comprises isolates of non-motile Bacillus pseudomycoides. Analysis of RNA-Seq data revealed cdgL to be expressed in a three-gene operon with a NupC like nucleoside transporter, and a putative glycosyl transferase for which transposon-based gene inactivation was previously shown to produce a similar phenotype to cdgL deletion. Interestingly, all three proteins were predicted to be membrane-bound and may provide a concerted function in the regulation of B. cereus group motility.
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15
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Liu L, Li Z, Luo X, Zhang X, Chou SH, Wang J, He J. Which Is Stronger? A Continuing Battle Between Cry Toxins and Insects. Front Microbiol 2021; 12:665101. [PMID: 34140940 PMCID: PMC8203666 DOI: 10.3389/fmicb.2021.665101] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
In this article, we review the latest works on the insecticidal mechanisms of Bacillus thuringiensis Cry toxins and the resistance mechanisms of insects against Cry toxins. Currently, there are two models of insecticidal mechanisms for Cry toxins, namely, the sequential binding model and the signaling pathway model. In the sequential binding model, Cry toxins are activated to bind to their cognate receptors in the mid-intestinal epithelial cell membrane, such as the glycophosphatidylinositol (GPI)-anchored aminopeptidases-N (APNs), alkaline phosphatases (ALPs), cadherins, and ABC transporters, to form pores that elicit cell lysis, while in the signaling pathway model, the activated Cry toxins first bind to the cadherin receptor, triggering an extensive cell signaling cascade to induce cell apoptosis. However, these two models cannot seem to fully describe the complexity of the insecticidal process of Cry toxins, and new models are required. Regarding the resistance mechanism against Cry toxins, the main method insects employed is to reduce the effective binding of Cry toxins to their cognate cell membrane receptors by gene mutations, or to reduce the expression levels of the corresponding receptors by trans-regulation. Moreover, the epigenetic mechanisms, host intestinal microbiota, and detoxification enzymes also play significant roles in the insects' resistance against Cry toxins. Today, high-throughput sequencing technologies like transcriptomics, proteomics, and metagenomics are powerful weapons for studying the insecticidal mechanisms of Cry toxins and the resistance mechanisms of insects. We believe that this review shall shed some light on the interactions between Cry toxins and insects, which can further facilitate the development and utilization of Cry toxins.
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Affiliation(s)
- Lu Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhou Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xing Luo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xia Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,Department of Molecular Biology, Qingdao Vland Biotech Inc., Qingdao, China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jieping Wang
- Agricultural Bioresources Institute, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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16
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Yin W, Cai X, Ma H, Zhu L, Zhang Y, Chou SH, Galperin MY, He J. A decade of research on the second messenger c-di-AMP. FEMS Microbiol Rev 2021; 44:701-724. [PMID: 32472931 DOI: 10.1093/femsre/fuaa019] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/28/2020] [Indexed: 02/07/2023] Open
Abstract
Cyclic dimeric adenosine 3',5'-monophosphate (c-di-AMP) is an emerging second messenger in bacteria and archaea that is synthesized from two molecules of ATP by diadenylate cyclases and degraded to pApA or two AMP molecules by c-di-AMP-specific phosphodiesterases. Through binding to specific protein- and riboswitch-type receptors, c-di-AMP regulates a wide variety of prokaryotic physiological functions, including maintaining the osmotic pressure, balancing central metabolism, monitoring DNA damage and controlling biofilm formation and sporulation. It mediates bacterial adaptation to a variety of environmental parameters and can also induce an immune response in host animal cells. In this review, we discuss the phylogenetic distribution of c-di-AMP-related enzymes and receptors and provide some insights into the various aspects of c-di-AMP signaling pathways based on more than a decade of research. We emphasize the key role of c-di-AMP in maintaining bacterial osmotic balance, especially in Gram-positive bacteria. In addition, we discuss the future direction and trends of c-di-AMP regulatory network, such as the likely existence of potential c-di-AMP transporter(s), the possibility of crosstalk between c-di-AMP signaling with other regulatory systems, and the effects of c-di-AMP compartmentalization. This review aims to cover the broad spectrum of research on the regulatory functions of c-di-AMP and c-di-AMP signaling pathways.
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Affiliation(s)
- Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Xia Cai
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Hongdan Ma
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Yuling Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
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17
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Yi Z, Zhang T, Xie J, Zhu Z, Luo S, Zhou K, Zhou P, Chen W, Zhao X, Sun Y, Xia L, Ding X. iTRAQ analysis reveals the effect of gabD and sucA gene knockouts on lysine metabolism and crystal protein formation in Bacillus thuringiensis. Environ Microbiol 2021; 23:2230-2243. [PMID: 33331075 DOI: 10.1111/1462-2920.15359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/08/2020] [Indexed: 11/27/2022]
Abstract
Lysine metabolism plays an important role in the formation of the insecticidal crystal proteins of Bacillus thuringiensis (Bt). The genes lam, gabD and sucA encode three key enzymes of the lysine metabolic pathway in Bt4.0718. The lam gene mainly affects the cell growth at stable period, negligibly affected sporulation and insecticidal crystal protein (ICP) production. While, the deletion mutant strains of the gabD and sucA genes showed that the growth, sporulation and crystal protein formation were inhibited, cells became slender, and insecticidal activity was significantly reduced. iTRAQ proteomics and qRT-PCR used to analyse the differentially expressed protein (DEP) between the two mutant strains and the wild type strain. The functions of DEPs were visualized and statistically classified, which affect bacterial growth and metabolism by regulating biological metabolism pathways: the major carbon metabolism pathways, amino acid metabolism, oxidative phosphorylation pathways, nucleic acid metabolism, fatty acid synthesis and peptidoglycan synthesis. The gabD and sucA genes in lysine metabolic pathway are closely related to the sporulation and crystal proteins formation. The effects of DEPs and functional genes on basic cellular metabolic pathways were studied to provide new strategies for the construction of highly virulent insecticidal strains, the targeted transformation of functional genes.
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Affiliation(s)
- Zixian Yi
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Tong Zhang
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Junyan Xie
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Zirong Zhu
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Sisi Luo
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Kexuan Zhou
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Pengji Zhou
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Wenhui Chen
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Xiaoli Zhao
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Yunjun Sun
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Liqiu Xia
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Xuezhi Ding
- Hunan Provincial Key Laboratory for Microbial Molecular Biology, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
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18
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Yin W, Xu S, Wang Y, Zhang Y, Chou SH, Galperin MY, He J. Ways to control harmful biofilms: prevention, inhibition, and eradication. Crit Rev Microbiol 2020; 47:57-78. [PMID: 33356690 DOI: 10.1080/1040841x.2020.1842325] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Biofilms are complex microbial architectures that encase microbial cells in a matrix comprising self-produced extracellular polymeric substances. Microorganisms living in biofilms are much more resistant to hostile environments than their planktonic counterparts and exhibit enhanced resistance against the microbicides. From the human perspective, biofilms can be classified into beneficial, neutral, and harmful. Harmful biofilms impact food safety, cause plant and animal diseases, and threaten medical fields, making it urgent to develop effective and robust strategies to control harmful biofilms. In this review, we discuss various strategies to control biofilm formation on infected tissues, implants, and medical devices. We classify the current strategies into three main categories: (i) changing the properties of susceptible surfaces to prevent biofilm formation; (ii) regulating signalling pathways to inhibit biofilm formation; (iii) applying external forces to eradicate the biofilm. We hope this review would motivate the development of innovative and effective strategies for controlling harmful biofilms.
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Affiliation(s)
- Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Siyang Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Yiting Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Yuling Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
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Smith V, Josefsen M, Lindbäck T, Hegna IK, Finke S, Tourasse NJ, Nielsen-LeRoux C, Økstad OA, Fagerlund A. MogR Is a Ubiquitous Transcriptional Repressor Affecting Motility, Biofilm Formation and Virulence in Bacillus thuringiensis. Front Microbiol 2020; 11:610650. [PMID: 33424814 PMCID: PMC7793685 DOI: 10.3389/fmicb.2020.610650] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
Flagellar motility is considered an important virulence factor in different pathogenic bacteria. In Listeria monocytogenes the transcriptional repressor MogR regulates motility in a temperature-dependent manner, directly repressing flagellar- and chemotaxis genes. The only other bacteria known to carry a mogR homolog are members of the Bacillus cereus group, which includes motile species such as B. cereus and Bacillus thuringiensis as well as the non-motile species Bacillus anthracis, Bacillus mycoides and Bacillus pseudomycoides. Furthermore, the main motility locus in B. cereus group bacteria, carrying the genes for flagellar synthesis, appears to be more closely related to L. monocytogenes than to Bacillus subtilis, which belongs to a separate phylogenetic group of Bacilli and does not carry a mogR ortholog. Here, we show that in B. thuringiensis, MogR overexpression results in non-motile cells devoid of flagella. Global gene expression profiling showed that 110 genes were differentially regulated by MogR overexpression, including flagellar motility genes, but also genes associated with virulence, stress response and biofilm lifestyle. Accordingly, phenotypic assays showed that MogR also affects cytotoxicity and biofilm formation in B. thuringiensis. Overexpression of a MogR variant mutated in two amino acids within the putative DNA binding domain restored phenotypes to those of an empty vector control. In accordance, introduction of these mutations resulted in complete loss in MogR binding to its candidate flagellar locus target site in vitro. In contrast to L. monocytogenes, MogR appears to be regulated in a growth-phase dependent and temperature-independent manner in B. thuringiensis 407. Interestingly, mogR was found to be conserved also in non-motile B. cereus group species such as B. mycoides and B. pseudomycoides, which both carry major gene deletions in the flagellar motility locus and where in B. pseudomycoides mogR is the only gene retained. Furthermore, mogR is expressed in non-motile B. anthracis. Altogether this provides indications of an expanded set of functions for MogR in B. cereus group species, beyond motility regulation. In conclusion, MogR constitutes a novel B. thuringiensis pleiotropic transcriptional regulator, acting as a repressor of motility genes, and affecting the expression of a variety of additional genes involved in biofilm formation and virulence.
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Affiliation(s)
- Veronika Smith
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Malin Josefsen
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Toril Lindbäck
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Ida K Hegna
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Sarah Finke
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Nicolas J Tourasse
- CNRS, INSERM, ARNA, UMR 5320, U1212, University of Bordeaux, Bordeaux, France
| | | | - Ole Andreas Økstad
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Annette Fagerlund
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
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20
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Li Z, Zhu L, Yu Z, Liu L, Chou SH, Wang J, He J. 6S-1 RNA Contributes to Sporulation and Parasporal Crystal Formation in Bacillus thuringiensis. Front Microbiol 2020; 11:604458. [PMID: 33324388 PMCID: PMC7726162 DOI: 10.3389/fmicb.2020.604458] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/04/2020] [Indexed: 11/13/2022] Open
Abstract
6S RNA is a kind of high-abundance non-coding RNA that globally regulates bacterial transcription by interacting with RNA polymerase holoenzyme. Through bioinformatics analysis, we found that there are two tandem 6S RNA-encoding genes in the genomes of Bacillus cereus group bacteria. Using Bacillus thuringiensis BMB171 as the starting strain, we have explored the physiological functions of 6S RNAs, and found that the genes ssrSA and ssrSB encoding 6S-1 and 6S-2 RNAs were located in the same operon and are co-transcribed as a precursor that might be processed by specific ribonucleases to form mature 6S-1 and 6S-2 RNAs. We also constructed two single-gene deletion mutant strains ΔssrSA and ΔssrSB and a double-gene deletion mutant strain ΔssrSAB by means of the markerless gene knockout method. Our data show that deletion of 6S-1 RNA inhibited the growth of B. thuringiensis in the stationary phase, leading to lysis of some bacterial cells. Furthermore, deletion of 6S-1 RNA also significantly reduced the spore number and parasporal crystal content. Our work reveals that B. thuringiensis 6S RNA played an important regulatory role in ensuring the sporulation and parasporal crystal formation.
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Affiliation(s)
- Zhou Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Lu Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jieping Wang
- Agricultural BioResources Institute, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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21
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Angeloni J, Dong Y, Wang Z, Cao M. Bacterial second messenger 3',5'-cyclic diguanylate attracts Caenorhabditis elegans and suppresses its immunity. Commun Biol 2020; 3:700. [PMID: 33219258 PMCID: PMC7679379 DOI: 10.1038/s42003-020-01436-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 10/26/2020] [Indexed: 11/29/2022] Open
Abstract
Cyclic di-nucleotides are important secondary signaling molecules in bacteria that regulate a wide range of processes. In this study, we found that Caenorhabditis elegans can detect and are attracted to multiple signal molecules produced by Vibrio cholerae, specifically the 3′,5′-cyclic diguanylate (c-di-GMP), even though this bacterium kills the host at a high rate. C-di-GMP is sensed through C. elegans olfactory AWC neurons, which then evokes a series of signal transduction pathways that lead to reduced activity of two key stress response transcription factors, SKN-1 and HSF-1, and weakened innate immunity. Taken together, our study elucidates the role of c-di-GMP in interkingdom communication. For C. elegans, bacterial c-di-GMP may serve as a cue that they can use to detect food. On the other hand, preexposure to low concentrations of c-di-GMP may impair their immune response, which could facilitate bacterial invasion and survival. Joseph Angeloni et al. show that Caenorhabditis elegans can detect and are attracted to multiple signal molecules produced by the bacterium Vibrio cholerae, specifically the 3′,5′-cyclic diguanylate (c-di-GMP), even though this bacterium kills the host at a high rate. This study reveals how bacterial c-di-GMP may serve as a cue for C. elegans that they can use to detect food or alternatively, impair their immune response, which could facilitate bacterial invasion and survival.
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Affiliation(s)
- Joseph Angeloni
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA
| | - Yuqing Dong
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA.,Institute for Engaged Aging, Clemson University, 2037 Barre Hall, Clemson, SC, 29634, USA
| | - Zeneng Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH, 44195, USA
| | - Min Cao
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC, 29634, USA. .,Institute for Engaged Aging, Clemson University, 2037 Barre Hall, Clemson, SC, 29634, USA.
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22
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Bhasme P, Wei Q, Xu A, Naqvi STA, Wang D, Ma LZ. Evaluation and characterization of the predicted diguanylate cyclase-encoding genes in Pseudomonas aeruginosa. Microbiologyopen 2020; 9:e975. [PMID: 32012489 PMCID: PMC7066473 DOI: 10.1002/mbo3.975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 02/06/2023] Open
Abstract
Opportunistic pathogen Pseudomonas aeruginosa can cause acute and chronic infections in humans. It is notorious for its resistance to antibiotics due to the formation of biofilms. Cyclic‐di‐GMP is a bacterial second messenger that plays important roles during biofilm development. There are 40 genes in P. aeruginosa predicted to participate in c‐di‐GMP biosynthesis or degradation. It is time‐consuming for the functional characterization of these genes. Here, we cloned 16 genes from P. aeruginosa PAO1 that are predicted to encode diguanylate cyclases (DGCs, responsible for c‐di‐GMP biosynthesis) and constructed their corresponding in‐frame deletion mutants. We evaluated the methods to measure the intracellular c‐di‐GMP concentration by using deletion mutants and PAO1 strains containing a plasmid expressing one of the 16 genes, respectively. Functional outputs of all PAO1‐derived stains were also detected and evaluated, including biofilm formation, production of exopolysaccharide, swimming and swarming motilities. Our data showed that measuring the c‐di‐GMP level only characterized a few DGC by using either pCdrA::gfp as a reporter or LC/MS/MS. Functional output results indicated that overexpression of a DGC gave more pronounced phenotypes than the corresponding deletion mutant and suggested that the swimming motility assay could be a quick way to briefly estimate a predicted DGC for further studies. The overall evaluation suggested 15 out of 16 predicted DGCs were functional DGCs, wherein six were characterized to encode DGCs previously. Altogether, we have provided not only a cloning library of 16 DGC‐encoding genes and their corresponding in‐frame deletion mutants but also paved ways to briefly characterize a predicted DGC.
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Affiliation(s)
- Pramod Bhasme
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qing Wei
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Anming Xu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Syed Tatheer Alam Naqvi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Di Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Luyan Z Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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23
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Zheng C, Yu Z, Du C, Gong Y, Yin W, Li X, Li Z, Römling U, Chou SH, He J. 2-Methylcitrate cycle: a well-regulated controller of Bacillus sporulation. Environ Microbiol 2019; 22:1125-1140. [PMID: 31858668 DOI: 10.1111/1462-2920.14901] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/26/2019] [Accepted: 12/16/2019] [Indexed: 12/23/2022]
Abstract
Bacillus thuringiensis is the most widely used eco-friendly biopesticide, containing two primary determinants of biocontrol, endospore and insecticidal crystal proteins (ICPs). The 2-methylcitrate cycle is a widespread carbon metabolic pathway playing a crucial role in channelling propionyl-CoA, but with poorly understood metabolic regulatory mechanisms. Here, we dissect the transcriptional regulation of the 2-methylcitrate cycle operon prpCDB and report its unprecedented role in controlling the sporulation process of B. thuringiensis. We found that the transcriptional activity of the prp operon encoding the three critical enzymes PrpC, PrpD, and PrpB in the 2-methylcitrate cycle was negatively regulated by the two global transcription factors CcpA and AbrB, while positively regulated by the LysR family regulator CcpC, which jointly account for the fact that the 2-methylcitrate cycle is specifically and highly active in the stationary phase of growth. We also found that the prpD mutant accumulated 2-methylcitrate, the intermediate metabolite of the 2-methylcitrate cycle, which delayed and inhibited sporulation at the early stage. Thus, our results not only revealed sophisticated transcriptional regulatory mechanisms for the metabolic 2-methylcitrate cycle but also identified 2-methylcitrate as a novel regulator of sporulation in B. thuringiensis.
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Affiliation(s)
- Cao Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.,Hubei Province Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables, College of Life Science and Technology, Hubei Engineering University, Xiaogan, Hubei, 432000, People's Republic of China
| | - Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Cuiying Du
- Hubei Province Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables, College of Life Science and Technology, Hubei Engineering University, Xiaogan, Hubei, 432000, People's Republic of China
| | - Yujing Gong
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Zhou Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
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24
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Xie J, Peng J, Yi Z, Zhao X, Li S, Zhang T, Quan M, Yang S, Lu J, Zhou P, Xia L, Ding X. Role of hsp20 in the Production of Spores and Insecticidal Crystal Proteins in Bacillus thuringiensis. Front Microbiol 2019; 10:2059. [PMID: 31551991 PMCID: PMC6737285 DOI: 10.3389/fmicb.2019.02059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 08/20/2019] [Indexed: 01/04/2023] Open
Abstract
The small heat shock protein plays an important role in response to stresses. We wanted to investigate how Hsp20 affects sporulation and production of insecticidal crystal proteins (ICPs) in Bacillus thuringiensis (Bt) at the stationary growth phase when cells are starved. The hsp20 gene was knocked out in Bt4.0718 (wide type), which is a B. thuringiensis strain screened in our laboratory, using endonuclease I-SceI mediated unmarked gene replacement method. Deletion of Hsp20 resulted in a decrease in both sporulation and ICPs production. Bt4-Δhsp20 cells and its ICP did not have a significant difference in shape and size but entered the decline phase 2 h earlier than the Bt4.0718. In order to find the mechanism that underlies these phenotypes, we completed a proteomic study of differentially expressed proteins (DEPs). In Bt4-Δhsp20 cells, 11 DEPs were upregulated and 184 DEPs downregulated. These affected DEPs are involved in multiple metabolic pathways: (1) six DEPs (two upregulated and four downregulated) are directly related to the sporulation and ICPs synthesis; (2) supply of amino acids including amino acid synthesis and protein recycling; (3) the energy supplementation (the tricarboxylic acid cycle and glycolysis); (4) purine metabolism and mRNA stability. These results suggest that hsp20 may be critical in maintaining the homeostasis of B. thuringiensis during the production of spores and ICPs, and could provide new sight into the sporulation and ICPs formation in B. thuringiensis.
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Affiliation(s)
- Junyan Xie
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Jinli Peng
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Zixian Yi
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Xiaoli Zhao
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Shuiming Li
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Tong Zhang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Meifang Quan
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Shuqing Yang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Jiaoyang Lu
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Pengji Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Liqiu Xia
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Xuezhi Ding
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
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25
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Jacek P, Dourado F, Gama M, Bielecki S. Molecular aspects of bacterial nanocellulose biosynthesis. Microb Biotechnol 2019; 12:633-649. [PMID: 30883026 PMCID: PMC6559022 DOI: 10.1111/1751-7915.13386] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 02/03/2019] [Accepted: 02/08/2019] [Indexed: 11/27/2022] Open
Abstract
Bacterial nanocellulose (BNC) produced by aerobic bacteria is a biopolymer with sophisticated technical properties. Although the potential for economically relevant applications is huge, the cost of BNC still limits its application to a few biomedical devices and the edible product Nata de Coco, made available by traditional fermentation methods in Asian countries. Thus, a wider economic relevance of BNC is still dependent on breakthrough developments on the production technology. On the other hand, the development of modified strains able to overproduce BNC with new properties - e.g. porosity, density of fibres crosslinking, mechanical properties, etc. - will certainly allow to overcome investment and cost production issues and enlarge the scope of BNC applications. This review discusses current knowledge about the molecular basis of BNC biosynthesis, its regulations and, finally, presents a perspective on the genetic modification of BNC producers made possible by the new tools available for genetic engineering.
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Affiliation(s)
- Paulina Jacek
- Institute of Technical BiochemistryLodz University of Technology4/10 Stefanowskiego Str90‐924LodzPoland
| | - Fernando Dourado
- Centre of Biological EngineeringUniversity of MinhoCampus de Gualtar4710‐057BragaPortugal
| | - Miguel Gama
- Centre of Biological EngineeringUniversity of MinhoCampus de Gualtar4710‐057BragaPortugal
| | - Stanisław Bielecki
- Institute of Technical BiochemistryLodz University of Technology4/10 Stefanowskiego Str90‐924LodzPoland
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26
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Wang X, Cai X, Ma H, Yin W, Zhu L, Li X, Lim HM, Chou SH, He J. A c-di-AMP riboswitch controlling kdpFABC operon transcription regulates the potassium transporter system in Bacillus thuringiensis. Commun Biol 2019; 2:151. [PMID: 31044176 PMCID: PMC6488665 DOI: 10.1038/s42003-019-0414-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 03/28/2019] [Indexed: 11/09/2022] Open
Abstract
The intracellular K+ level in bacteria is strictly controlled by K+ uptake and efflux systems. Among these, KdpFABC is a high-affinity K+ transporter system that is generally activated by the KdpDE two-component system in response to K+ limitation stress. However, the regulatory mechanism remains obscure in bacteria lacking the kdpDE genes. Here we report that the transcription of a kdpFABC operon is distinctively regulated by a cyclic diadenylate monophosphate (c-di-AMP) riboswitch located at the 5'-untranslated region of kdp transcript, and binding of c-di-AMP to the riboswitch promotes its intrinsic termination that blocks the kdpFABC transcription. Further, the intracellular c-di-AMP concentration was found to decrease under the K+ limitation stress, leading to transcriptional read-through over the terminator to allow kdpFABC expression. This regulatory element is found predominantly in the Bacillus cereus group and correlate well with the K+ and c-di-AMP homeostasis that affects a variety of crucial cellular functions.
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Affiliation(s)
- Xun Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Xia Cai
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Hongdan Ma
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Wen Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Li Zhu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
| | - Heon M. Lim
- Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Shan-Ho Chou
- Institute of Biochemistry and Agricultural Biotechnology Center, National Chung Hsing University, Taichung, 40227 Taiwan
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 PR China
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27
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He J, Ruan W, Sun J, Wang F, Yan W. Functional Characterization of c-di-GMP Signaling-Related Genes in the Probiotic Lactobacillus acidophilus. Front Microbiol 2018; 9:1935. [PMID: 30210464 PMCID: PMC6123363 DOI: 10.3389/fmicb.2018.01935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 07/30/2018] [Indexed: 01/03/2023] Open
Abstract
The bacterial second messenger cyclic diguanylate monophosphate (c-di-GMP) regulates a series of cellular functions, including biofilm formation, motility, virulence, and other processes. In this study, we confirmed the presence of several c-di-GMP related genes and evaluated their activities and functions in Lactobacillus species. Bioinformatic and biochemical analyses revealed that Lactobacillus acidophilus La-14 have an active c-di-GMP phosphodiesterase (PdeA) that may act in the metabolic cycle of c-di-GMP. A GGDEF protein (DgcA) induced two c-di-GMP-dependent phenotypes (low motility and high production of curli fimbriae) in Escherichia coli by heterologously expressed in vivo but showed no diguanylate cyclases activity in vitro while in the expression without the N-terminal transmembrane domain. The degenerated EAL-domain protein (PdeB), encoded by the last gene in the gts operon, serve as a c-di-GMP receptor which may be associated with exopolysaccharide (EPS) synthesis in L. acidophilus. Heterologously expressed GtsA and GtsB, encoded by the gts operon, stimulated EPS and biofilm formation in E. coli BL21. Constitutive expression in L. acidophilus revealed that a high concentration of intracellular DgcA levels increased EPS production in L. acidophilus and enhanced the co-aggregation ability with E. coli MG1655, which may be beneficial to the probiotic properties of Lactobacillus species. Our study imply that the c-di-GMP metabolism-related genes, in L. acidophilus, work jointly to regulate its functions in EPS formation and co-aggregation.
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Affiliation(s)
- Jiahui He
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Department of Neurobiology, School of Basic Medical Science, Southern Medical University, Guangzhou, China.,Department of Stomatology, The Affiliated Shenzhen Maternity and Child Healthcare Hospital of the South Medical University, Shenzhen, China
| | - Wenhao Ruan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jieli Sun
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Fang Wang
- Department of Neurobiology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Wenjuan Yan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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