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Rawson AM, Dempster AW, Humphreys CM, Minton NP. Pathogenicity and virulence of Clostridium botulinum. Virulence 2023; 14:2205251. [PMID: 37157163 PMCID: PMC10171130 DOI: 10.1080/21505594.2023.2205251] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Clostridium botulinum, a polyphyletic Gram-positive taxon of bacteria, is classified purely by their ability to produce botulinum neurotoxin (BoNT). BoNT is the primary virulence factor and the causative agent of botulism. A potentially fatal disease, botulism is classically characterized by a symmetrical descending flaccid paralysis, which is left untreated can lead to respiratory failure and death. Botulism cases are classified into three main forms dependent on the nature of intoxication; foodborne, wound and infant. The BoNT, regarded as the most potent biological substance known, is a zinc metalloprotease that specifically cleaves SNARE proteins at neuromuscular junctions, preventing exocytosis of neurotransmitters, leading to muscle paralysis. The BoNT is now used to treat numerous medical conditions caused by overactive or spastic muscles and is extensively used in the cosmetic industry due to its high specificity and the exceedingly small doses needed to exert long-lasting pharmacological effects. Additionally, the ability to form endospores is critical to the pathogenicity of the bacteria. Disease transmission is often facilitated via the metabolically dormant spores that are highly resistant to environment stresses, allowing persistence in the environment in unfavourable conditions. Infant and wound botulism infections are initiated upon germination of the spores into neurotoxin producing vegetative cells, whereas foodborne botulism is attributed to ingestion of preformed BoNT. C. botulinum is a saprophytic bacterium, thought to have evolved its potent neurotoxin to establish a source of nutrients by killing its host.
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Affiliation(s)
- Alexander M Rawson
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
| | - Andrew W Dempster
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
| | - Christopher M Humphreys
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
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2
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Mertaoja A, Mascher G, Nowakowska MB, Korkeala H, Henriques AO, Lindstrom M. Cellular and population strategies underpinning neurotoxin production and sporulation in Clostridium botulinum type E cultures. mBio 2023; 14:e0186623. [PMID: 37971252 PMCID: PMC10746260 DOI: 10.1128/mbio.01866-23] [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: 07/15/2023] [Accepted: 10/06/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Toxin production and sporulation are key determinants of pathogenesis in Clostridia. Toxins cause the clinical manifestation of clostridial diseases, including diarrhea and colitis, tissue damage, and systemic effects on the nervous system. Spores ensure long-term survival and persistence in the environment, act as infectious agents, and initiate the host tissue colonization leading to infection. Understanding the interplay between toxin production and sporulation and their coordination in bacterial cells and cultures provides novel intervention points for controlling the public health and food safety risks caused by clostridial diseases. We demonstrate environmentally driven cellular heterogeneity in botulinum neurotoxin and spore production in Clostridium botulinum type E populations and discuss the biological rationale of toxin and spore production in the pathogenicity and ecology of C. botulinum. The results invite to reassess the epidemiology of botulism and may have important implications in the risk assessment and risk management strategies in food processing and human and animal health.
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Affiliation(s)
- Anna Mertaoja
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Gerald Mascher
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Maria B. Nowakowska
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Adriano O. Henriques
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Miia Lindstrom
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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Isawumi A, Ayerakwa EA, Abban MK, Mosi L. Expression profiles of sporulation genes in multidrug-resistant Bacillus species isolated from intensive care units of Ghanaian hospital. Exp Biol Med (Maywood) 2023; 248:501-507. [PMID: 37092757 PMCID: PMC10281534 DOI: 10.1177/15353702231160336] [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: 10/25/2022] [Accepted: 01/24/2023] [Indexed: 04/25/2023] Open
Abstract
Sporulating bacteria such as Bacillus spp. have contributed to severity of opportunistic hospital acquired infections, including postoperative wounds and respiratory tract infections. This study determines the expression profiles of sporulation markers in multidrug-resistant Bacillus spp. isolated from Ghanaian hospital environments. Antimicrobial resistance (AMR) profiles of the bacteria were determined with disk diffusion and broth microdilution. Primer-specific polymerase chain reaction (PCR) amplification was used to profile the sporulation markers, and quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used for the expression of the sporulation markers at different antibiotic concentrations. The strains are multidrug resistant (70-100%) to at least two of the eight classes of the antibiotics tested including cephalosporins, penicillin, aminoglycosides, and glycopeptide. The strains showed different resistance patterns to all the tested antibiotics, which might indicate diverse resistance mechanisms. Common (spoVK spoVE, spoJ, and sigF) and not commonly (sigJ, soJ, yrbC, and yjcE) reported sporulation markers were detected in the strains. The study showed an association of the sporulation markers with AMR as indicated by their expression profiles.
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Affiliation(s)
- Abiola Isawumi
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
| | - Eunice Ampadubea Ayerakwa
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
| | - Molly Kukua Abban
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
| | - Lydia Mosi
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Volta Road, P.O. Box LG 54, Legon, Accra, Ghana
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Regulatory Networks Controlling Neurotoxin Synthesis in Clostridium botulinum and Clostridium tetani. Toxins (Basel) 2022; 14:toxins14060364. [PMID: 35737025 PMCID: PMC9229411 DOI: 10.3390/toxins14060364] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/16/2022] [Accepted: 05/21/2022] [Indexed: 12/30/2022] Open
Abstract
Clostridium botulinum and Clostridium tetani are Gram-positive, spore-forming, and anaerobic bacteria that produce the most potent neurotoxins, botulinum toxin (BoNT) and tetanus toxin (TeNT), responsible for flaccid and spastic paralysis, respectively. The main habitat of these toxigenic bacteria is the environment (soil, sediments, cadavers, decayed plants, intestinal content of healthy carrier animals). C. botulinum can grow and produce BoNT in food, leading to food-borne botulism, and in some circumstances, C. botulinum can colonize the intestinal tract and induce infant botulism or adult intestinal toxemia botulism. More rarely, C. botulinum colonizes wounds, whereas tetanus is always a result of wound contamination by C. tetani. The synthesis of neurotoxins is strictly regulated by complex regulatory networks. The highest levels of neurotoxins are produced at the end of the exponential growth and in the early stationary growth phase. Both microorganisms, except C. botulinum E, share an alternative sigma factor, BotR and TetR, respectively, the genes of which are located upstream of the neurotoxin genes. These factors are essential for neurotoxin gene expression. C. botulinum and C. tetani share also a two-component system (TCS) that negatively regulates neurotoxin synthesis, but each microorganism uses additional distinct sets of TCSs. Neurotoxin synthesis is interlocked with the general metabolism, and CodY, a master regulator of metabolism in Gram-positive bacteria, is involved in both clostridial species. The environmental and nutritional factors controlling neurotoxin synthesis are still poorly understood. The transition from amino acid to peptide metabolism seems to be an important factor. Moreover, a small non-coding RNA in C. tetani, and quorum-sensing systems in C. botulinum and possibly in C. tetani, also control toxin synthesis. However, both species use also distinct regulatory pathways; this reflects the adaptation of C. botulinum and C. tetani to different ecological niches.
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Portinha IM, Douillard FP, Korkeala H, Lindström M. Sporulation Strategies and Potential Role of the Exosporium in Survival and Persistence of Clostridium botulinum. Int J Mol Sci 2022; 23:ijms23020754. [PMID: 35054941 PMCID: PMC8775613 DOI: 10.3390/ijms23020754] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/31/2021] [Accepted: 01/07/2022] [Indexed: 01/21/2023] Open
Abstract
Clostridium botulinum produces the botulinum neurotoxin that causes botulism, a rare but potentially lethal paralysis. Endospores play an important role in the survival, transmission, and pathogenesis of C. botulinum. C. botulinum strains are very diverse, both genetically and ecologically. Group I strains are terrestrial, mesophilic, and produce highly heat-resistant spores, while Group II strains can be terrestrial (type B) or aquatic (type E) and are generally psychrotrophic and produce spores of moderate heat resistance. Group III strains are either terrestrial or aquatic, mesophilic or slightly thermophilic, and the heat resistance properties of their spores are poorly characterized. Here, we analyzed the sporulation dynamics in population, spore morphology, and other spore properties of 10 C. botulinum strains belonging to Groups I–III. We propose two distinct sporulation strategies used by C. botulinum Groups I–III strains, report their spore properties, and suggest a putative role for the exosporium in conferring high heat resistance. Strains within each physiological group produced spores with similar characteristics, likely reflecting adaptation to respective environmental habitats. Our work provides new information on the spores and on the population and single-cell level strategies in the sporulation of C. botulinum.
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Mertaoja A, Nowakowska MB, Mascher G, Heljanko V, Groothuis D, Minton NP, Lindström M. CRISPR-Cas9-Based Toolkit for Clostridium botulinum Group II Spore and Sporulation Research. Front Microbiol 2021; 12:617269. [PMID: 33584620 PMCID: PMC7873358 DOI: 10.3389/fmicb.2021.617269] [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: 10/14/2020] [Accepted: 01/05/2021] [Indexed: 01/05/2023] Open
Abstract
The spores of Clostridium botulinum Group II strains pose a significant threat to the safety of modern packaged foods due to the risk of their survival in pasteurization and their ability to germinate into neurotoxigenic cultures at refrigeration temperatures. Moreover, spores are the infectious agents in wound botulism, infant botulism, and intestinal toxemia in adults. The identification of factors that contribute to spore formation is, therefore, essential to the development of strategies to control related health risks. Accordingly, development of a straightforward and versatile gene manipulation tool and an efficient sporulation-promoting medium is pivotal. Our strategy was to employ CRISPR-Cas9 and homology-directed repair (HDR) to replace targeted genes with mutant alleles incorporating a unique 24-nt "bookmark" sequence that could act as a single guide RNA (sgRNA) target for Cas9. Following the generation of the sporulation mutant, the presence of the bookmark allowed rapid generation of a complemented strain, in which the mutant allele was replaced with a functional copy of the deleted gene using CRISPR-Cas9 and the requisite sgRNA. Then, we selected the most appropriate medium for sporulation studies in C. botulinum Group II strains by measuring the efficiency of spore formation in seven different media. The most effective medium was exploited to confirm the involvement of a candidate gene in the sporulation process. Using the devised sporulation medium, subsequent comparisons of the sporulation efficiency of the wild type (WT), mutant and "bookmark"-complemented strain allowed the assignment of any defective sporulation phenotype to the mutation made. As a strain generated by complementation with the WT gene in the original locus would be indistinguishable from the parental strain, the gene utilized in complementation studies was altered to contain a unique "watermark" through the introduction of silent nucleotide changes. The mutagenesis system and the devised sporulation medium provide a solid basis for gaining a deeper understanding of spore formation in C. botulinum, a prerequisite for the development of novel strategies for spore control and related food safety and public health risk management.
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Affiliation(s)
- Anna Mertaoja
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Maria B. Nowakowska
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Gerald Mascher
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Viivi Heljanko
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Daphne Groothuis
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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Li W, Cheng C, Cao G, Yang ST, Ren N. Comparative transcriptome analysis of Clostridium tyrobutyricum expressing a heterologous uptake hydrogenase. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:142022. [PMID: 33370888 DOI: 10.1016/j.scitotenv.2020.142022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 06/12/2023]
Abstract
Clostridium tyrobutyricum is a promising microbial cell factory to produce biofuels. In this study, an uptake hydrogenase (hyd2293) from Ethanoligenens harbinense was overexpressed in C. tyrobutyricum and significantly affected the redox reactions and metabolic profiles. Compared to the parental strain (Ct-WT), the mutant strain Ct-Hyd2293 produced ~34% less butyrate, ~148% more acetate, and ~11% less hydrogen, accompanied by the emerging genesis of butanol. Comparative transcriptome analysis revealed that 666 genes were significantly differentially expressed after the overexpression of hyd2293, including 82 up-regulated genes and 584 down-regulated genes. The up-regulated genes were mainly involved in carbohydrate and energy metabolisms while the down-regulated genes were distributed in nearly all pathways. Genes involved in glucose transportation, glycolysis, different fermentation pathways and hydrogen metabolism were studied and the gene expression changes showed the mechanism of the metabolic flux redistribution in Ct-Hyd2293. The overexpression of uptake hydrogenase redirected electrons from hydrogen and butyrate to butanol. The key enzymes participating in the energy conservation and sporulation were also identified and their transcription levels were generally reduced. This study demonstrated the transcriptomic responses of C. tyrobutyricum to the expression of a heterologous uptake hydrogenase, which provided a better understanding of the metabolic characteristics of C. tyrobutyricum and demonstrated the potential role of redox manipulation in metabolic engineering for biofuel productions.
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Affiliation(s)
- Weiming Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Chi Cheng
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA; School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Guangli Cao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shang-Tian Yang
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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Effects of Spo0A on Clostridium acetobutylicum with an emphasis on biofilm formation. World J Microbiol Biotechnol 2020; 36:80. [PMID: 32444896 DOI: 10.1007/s11274-020-02859-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 05/18/2020] [Indexed: 02/08/2023]
Abstract
Clostridium acetobutylicum is a well-known strain for biofuel production. In previous work, it was found that this strain formed biofilm readily during fermentation processes. Biofilm formation could protect cells and enhance productivities under environmental stresses in our previous work. To explore the molecular mechanism of biofilm formation, Spo0A of C. acetobutylicum was selected to investigate its influences on biofilm formation and other physiological performances. When spo0A gene was disrupted, the spo0A mutant could hardly form biofilm. The aggregation and adhesion abilities of the spo0A mutant as well as its swarming motility were dramatically reduced compared to those of wild type strain. Sporulation was also negatively influenced by spo0A disruption, and solvent production was almost undetectable in the spo0A mutant fermentation. Furthermore, proteomic differences between wild type strain and the spo0A mutant were consistent with physiological performances. This is the first study confirming a genetic clue to C. acetobutylicum biofilm and will be valuable for biofilm optimization through genetic engineering in the future.
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9
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Shen A, Edwards AN, Sarker MR, Paredes-Sabja D. Sporulation and Germination in Clostridial Pathogens. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0017-2018. [PMID: 31858953 PMCID: PMC6927485 DOI: 10.1128/microbiolspec.gpp3-0017-2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Indexed: 12/14/2022] Open
Abstract
As obligate anaerobes, clostridial pathogens depend on their metabolically dormant, oxygen-tolerant spore form to transmit disease. However, the molecular mechanisms by which those spores germinate to initiate infection and then form new spores to transmit infection remain poorly understood. While sporulation and germination have been well characterized in Bacillus subtilis and Bacillus anthracis, striking differences in the regulation of these processes have been observed between the bacilli and the clostridia, with even some conserved proteins exhibiting differences in their requirements and functions. Here, we review our current understanding of how clostridial pathogens, specifically Clostridium perfringens, Clostridium botulinum, and Clostridioides difficile, induce sporulation in response to environmental cues, assemble resistant spores, and germinate metabolically dormant spores in response to environmental cues. We also discuss the direct relationship between toxin production and spore formation in these pathogens.
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Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University Medical School, Boston, MA
| | - Adrianne N Edwards
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Mahfuzur R Sarker
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR
| | - Daniel Paredes-Sabja
- Department of Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biolo gicas, Facultad de Ciencias Biologicas, Universidad Andres Bello, Santiago, Chile
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10
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Zhou C, Zhou H, Zhang H, Lu F. Optimization of alkaline protease production by rational deletion of sporulation related genes in Bacillus licheniformis. Microb Cell Fact 2019; 18:127. [PMID: 31345221 PMCID: PMC6657089 DOI: 10.1186/s12934-019-1174-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/17/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Our laboratory has constructed a Bacillus licheniformis strain that secretes alkaline protease (AprE) with excellent enzymatic properties. B. licheniformis is generally regarded as safe and has a high industrial exoenzyme secretion capacity, but the host retains some undomesticated characteristic that increase its competitiveness and survival, such as spore-formation, which increases the requirements and difficulties in industrial operations (e.g. sterilization and enzyme activity control). Furthermore, the influence of sporulation on alkaline protease production in B. licheniformis has not been elucidated in detail. RESULT A series of asporogenic variants of the parent strain were constructed by individually knocking out the master regulator genes (spo0A, sigF and sigE) involved in sporulation. Most of the variants formed abortively disporic cells characterized by asymmetric septa at the poles and unable to survive incubation at 75 °C for 10 min. Two of them (ΔsigF and ΔsigE) exhibited superior characteristics in protease production, especially improving the expression of the aprE gene. Under the currently used fermentation conditions, the vegetative production phase of ΔsigF can be prolonged to 72 h, and the highest protease production of ΔsigF reached 29,494 ± 1053 U/mL, which was about 19.7% higher than that of the wild-type strain. CONCLUSION We first constructed three key sporulation-deficient strain to investigate the effect of sporulation on alkaline protease synthesis. The sigF mutant retained important industrial properties such as facilitating the sterilization process, a prolonged stable phase of enzyme production and slower decreasing trend, which will be superior in energy conservation, simpler operations and target product controlling effect. In summary, the work provides a useful industrial host with preferable characteristics and a novel strategy to enhance the production of protease.
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Affiliation(s)
- Cuixia Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Huiying Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China
| | - Huitu Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China.
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science & Technology, No. 29, 13th Road, Tianjin Economic-Technological Development Area, Tianjin 022, 300457, People's Republic of China.
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Zaikova E, Goerlitz DS, Tighe SW, Wagner NY, Bai Y, Hall BL, Bevilacqua JG, Weng MM, Samuels-Fair MD, Johnson SS. Antarctic Relic Microbial Mat Community Revealed by Metagenomics and Metatranscriptomics. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00001] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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Chellapandi P, Prisilla A. Clostridium botulinum type A-virulome-gut interactions: A systems biology insight. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.humic.2018.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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13
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Mascher G, Mertaoja A, Korkeala H, Lindström M. Neurotoxin synthesis is positively regulated by the sporulation transcription factor Spo0A in Clostridium botulinum type E. Environ Microbiol 2017; 19:4287-4300. [PMID: 28809452 DOI: 10.1111/1462-2920.13892] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 12/11/2022]
Abstract
Clostridium botulinum produces the most potent natural toxin, the botulinum neurotoxin (BoNT), probably to create anaerobiosis and nutrients by killing the host, and forms endospores that facilitate survival in harsh conditions and transmission. Peak BoNT production coincides with initiation of sporulation in C. botulinum cultures, which suggests common regulation. Here, we show that Spo0A, the master regulator of sporulation, positively regulates BoNT production. Insertional inactivation of spo0A in C. botulinum type E strain Beluga resulted in significantly reduced BoNT production and in abolished or highly reduced sporulation in relation to wild-type controls. Complementation with spo0A restored BoNT production and sporulation. Recombinant DNA-binding domain of Spo0A directly bound to a putative Spo0A-binding box (CTTCGAA) within the BoNT/E operon promoter, demonstrating direct regulation. Spo0A is the first neurotoxin regulator reported in C. botulinum type E. Unlike other C. botulinum strains that are terrestrial and employ the alternative sigma factor BotR in directing BoNT expression, C. botulinum type E strains are adapted to aquatic ecosystems, possess distinct epidemiology and lack BotR. Our results provide fundamental new knowledge on the genetic control of BoNT production and demonstrate common regulation of BoNT production and sporulation, providing a key intervention point for control.
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Affiliation(s)
- Gerald Mascher
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Mertaoja
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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14
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Selby K, Mascher G, Somervuo P, Lindström M, Korkeala H. Heat shock and prolonged heat stress attenuate neurotoxin and sporulation gene expression in group I Clostridium botulinum strain ATCC 3502. PLoS One 2017; 12:e0176944. [PMID: 28464023 PMCID: PMC5413062 DOI: 10.1371/journal.pone.0176944] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 04/19/2017] [Indexed: 12/11/2022] Open
Abstract
Foodborne pathogenic bacteria are exposed to a number of environmental stresses during food processing, storage, and preparation, and in the human body. In order to improve the safety of food, the understanding of molecular stress response mechanisms foodborne pathogens employ is essential. Many response mechanisms that are activated during heat shock may cross-protect bacteria against other environmental stresses. To better understand the molecular mechanisms Clostridium botulinum, the causative agent of botulism, utilizes during acute heat stress and during adaptation to stressfully high temperature, the C. botulinum Group I strain ATCC 3502 was grown in continuous culture at 39°C and exposed to heat shock at 45°C, followed by prolonged heat stress at 45°C to allow adaptation of the culture to the high temperature. Growth in continuous culture was performed to exclude secondary growth phase effects or other environmental impacts on bacterial gene transcription. Changes in global gene expression profiles were studied using DNA microarray hybridization. During acute heat stress, Class I and III heat shock genes as well as members of the SOS regulon were activated. The neurotoxin gene botA and genes encoding the neurotoxin-associated proteins were suppressed throughout the study. Prolonged heat stress led to suppression of the sporulation machinery whereas genes related to chemotaxis and motility were activated. Induced expression of a large proportion of prophage genes was detected, suggesting an important role of acquired genes in the stress resistance of C. botulinum. Finally, changes in the expression of a large number of genes related to carbohydrate and amino acid metabolism indicated remodeling of the cellular metabolism.
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Affiliation(s)
- Katja Selby
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Gerald Mascher
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Panu Somervuo
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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Gauvry E, Mathot AG, Leguérinel I, Couvert O, Postollec F, Broussolle V, Coroller L. Knowledge of the physiology of spore-forming bacteria can explain the origin of spores in the food environment. Res Microbiol 2017; 168:369-378. [DOI: 10.1016/j.resmic.2016.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/22/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
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Zhang Y, Jiao S, Lv J, Du R, Yan X, Wan C, Zhang R, Han B. Sigma Factor Regulated Cellular Response in a Non-solvent Producing Clostridium beijerinckii Degenerated Strain: A Comparative Transcriptome Analysis. Front Microbiol 2017; 8:23. [PMID: 28194137 PMCID: PMC5276810 DOI: 10.3389/fmicb.2017.00023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/04/2017] [Indexed: 01/11/2023] Open
Abstract
Clostridium beijerinckii DG-8052, derived from NCIMB 8052, cannot produce solvent or form spores, a phenomenon known as degeneration. To explore the mechanisms of degeneration at the gene level, transcriptomic profiles of the wild-type 8052 and DG-8052 strains were compared. Expression of 5168 genes comprising 98.6% of the genome was assessed. Interestingly, 548 and 702 genes were significantly up-regulated in the acidogenesis and solventogenesis phases of DG-8052, respectively, and mainly responsible for the phosphotransferase system, sugar metabolic pathways, and chemotaxis; meanwhile, 699 and 797 genes were significantly down-regulated, respectively, and mainly responsible for sporulation, oxidoreduction, and solventogenesis. The functions of some altered genes, including 286 and 333 at the acidogenesis and solventogenesis phases, respectively, remain unknown. Dysregulation of the fermentation machinery was accompanied by lower transcription levels of glycolysis rate-limiting enzymes (pfk and pyk), and higher transcription of cell chemotaxis genes (cheA, cheB, cheR, cheW, and cheY), controlled mainly by σ54 at acidogenesis. Meanwhile, abnormal spore formation was associated with repressed spo0A, sigE, sigF, sigG, and sigK which are positively regulated by σ70, and correspondingly inhibited expression of CoA-transferase at the solventogenesis phase. These findings indicated that morphological and physiological changes in the degenerated Clostridium strain may be related to altered expression of sigma factors, providing valuable targets for strain development of Clostridium species.
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Affiliation(s)
- Yan Zhang
- School of Medicine, Institute for Genome Sciences, University of Maryland, Baltimore MD, USA
| | - Shengyin Jiao
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
| | - Jia Lv
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
| | - Renjia Du
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
| | - Xiaoni Yan
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
| | - Caixia Wan
- Department of Bioengineering, University of Missouri, Columbia MO, USA
| | - Ruijuan Zhang
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
| | - Bei Han
- School of Public Health, Health Science Center, Xi'an Jiaotong University Xi'an, China
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17
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Transcriptional analysis of degenerate strain Clostridium beijerinckii DG-8052 reveals a pleiotropic response to CaCO 3-associated recovery of solvent production. Sci Rep 2016; 6:38818. [PMID: 27966599 PMCID: PMC5155275 DOI: 10.1038/srep38818] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022] Open
Abstract
Degenerate Clostridium beijerinckii strain (DG-8052) can be partially recovered by supplementing CaCO3 to fermentation media. Genome resequencing of DG-8052 showed no general regulator mutated. This study focused on transcriptional analysis of DG-8052 and its response to CaCO3 treatment via microarray. The expressions of 5168 genes capturing 98.6% of C. beijerinckii NCIMB 8052 genome were examed. The results revealed that with addition of CaCO3 565 and 916 genes were significantly up-regulated, and 704 and 1044 genes significantly down-regulated at acidogenic and solventogenic phase of DG-8052, respectively. These genes are primarily responsible for glycolysis to solvent/acid production (poR, pfo), solventogensis (buk, ctf, aldh, adh, bcd) and sporulation (spo0A, sigE, sigma-70, bofA), cell motility and division (ftsA, ftsK, ftsY, ftsH, ftsE, mreB, mreC, mreD, rodA), and molecular chaperones (grpE, dnaK, dnaJ, hsp20, hsp90), etc. The functions of some altered genes in DG-8052, totalling 5.7% at acidogenisis and 8.0% at sovlentogenisis, remain unknown. The response of the degenerate strain to CaCO3 was suggested significantly pleiotropic. This study reveals the multitude of regulatory function that CaCO3 has in clostridia and provides detailed insights into degeneration mechanisms at gene regulation level. It also enables us to develop effective strategies to prevent strain degeneration in future.
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The Clostridium sporulation programs: diversity and preservation of endospore differentiation. Microbiol Mol Biol Rev 2015; 79:19-37. [PMID: 25631287 DOI: 10.1128/mmbr.00025-14] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
SUMMARY Bacillus and Clostridium organisms initiate the sporulation process when unfavorable conditions are detected. The sporulation process is a carefully orchestrated cascade of events at both the transcriptional and posttranslational levels involving a multitude of sigma factors, transcription factors, proteases, and phosphatases. Like Bacillus genomes, sequenced Clostridium genomes contain genes for all major sporulation-specific transcription and sigma factors (spo0A, sigH, sigF, sigE, sigG, and sigK) that orchestrate the sporulation program. However, recent studies have shown that there are substantial differences in the sporulation programs between the two genera as well as among different Clostridium species. First, in the absence of a Bacillus-like phosphorelay system, activation of Spo0A in Clostridium organisms is carried out by a number of orphan histidine kinases. Second, downstream of Spo0A, the transcriptional and posttranslational regulation of the canonical set of four sporulation-specific sigma factors (σ(F), σ(E), σ(G), and σ(K)) display different patterns, not only compared to Bacillus but also among Clostridium organisms. Finally, recent studies demonstrated that σ(K), the last sigma factor to be activated according to the Bacillus subtilis model, is involved in the very early stages of sporulation in Clostridium acetobutylicum, C. perfringens, and C. botulinum as well as in the very late stages of spore maturation in C. acetobutylicum. Despite profound differences in initiation, propagation, and orchestration of expression of spore morphogenetic components, these findings demonstrate not only the robustness of the endospore sporulation program but also the plasticity of the program to generate different complex phenotypes, some apparently regulated at the epigenetic level.
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Meaney CA, Cartman ST, McClure PJ, Minton NP. Optimal spore germination in Clostridium botulinum ATCC 3502 requires the presence of functional copies of SleB and YpeB, but not CwlJ. Anaerobe 2015; 34:86-93. [PMID: 25937262 DOI: 10.1016/j.anaerobe.2015.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/10/2015] [Accepted: 04/28/2015] [Indexed: 10/23/2022]
Abstract
Germination, the process by which dormant endospores return to vegetative growth, is a critical process in the life cycle of the notorious pathogen Clostridium botulinum. Crucial is the degradation by hydrolytic enzymes of an inner peptidoglycan spore layer termed the cortex. Two mechanistically different systems of cortex lysis exist in spores of Clostridium species. C. botulinum ATCC 3502 harbours the Bacillus-like system of SleB, CwlJ and YpeB cortex lytic enzymes (CLEs). Through the construction of insertional gene knockout mutants in the sleB, cwlJ and ypeB genes of C. botulinum ATCC 3502 and the production of spores of each mutant strain, the effect on germination was assessed. This study demonstrates a reduced germination efficiency in spores carrying mutations in either sleB or ypeB with an approximate 2-fold reduction in heat resistant colony forming units (CFU/OD600) when plated on rich media. This reduction could be restored to wild-type levels by removing the spore coat and plating on media supplemented with lysozyme. It was observed that cwlJ spores displayed a similar germination efficiency as wild-type spores (P > 0.05). An optimal germinant commixture was identified to include a combination of l-alanine with sodium bicarbonate as it resulted in a 32% drop in OD600, while the additional incorporation of l-lactate resulted in a 57% decrease. Studies of the germination efficiency of spores prepared from all three CLE mutants was performed by monitoring the associated decrease in optical density but a germination defect was not observed in any of the CLE mutant strains. This was likely due to the lack of specificity of this particular assay. Taken together, these data indicate that functional copies of SleB and YpeB, but not CwlJ are required for the optimal germination of the spores of C. botulinum ATCC 3502.
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Affiliation(s)
- Carolyn A Meaney
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Stephen T Cartman
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | | | - Nigel P Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
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20
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Fimlaid KA, Shen A. Diverse mechanisms regulate sporulation sigma factor activity in the Firmicutes. Curr Opin Microbiol 2015; 24:88-95. [PMID: 25646759 DOI: 10.1016/j.mib.2015.01.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/23/2014] [Accepted: 01/10/2015] [Indexed: 11/27/2022]
Abstract
Sporulation allows bacteria to survive adverse conditions and is essential to the lifecycle of some obligate anaerobes. In Bacillus subtilis, the sporulation-specific sigma factors, σ(F), σ(E), σ(G), and σ(K), activate compartment-specific transcriptional programs that drive sporulation through its morphological stages. The regulation of these sigma factors was predicted to be conserved across the Firmicutes, since the regulatory proteins controlling their activation are largely conserved. However, recent studies in (Pepto)Clostridium difficile, Clostridium acetobutylicum, Clostridium perfringens, and Clostridium botulinum have revealed striking differences in the order, activation, and function of sporulation sigma factors. These studies indicate that gene conservation does not necessarily predict gene function and that new mechanisms for controlling cell fate determination remain to be discovered in the anaerobic Clostridia.
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Affiliation(s)
- Kelly A Fimlaid
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA; Cellular, Molecular and Biomedical Sciences Program, University of Vermont, Burlington, VT 05405, USA
| | - Aimee Shen
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA.
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21
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Hosomi K, Kuwana R, Takamatsu H, Kohda T, Kozaki S, Mukamoto M. Morphological and genetic characterization of group I Clostridium botulinum type B strain 111 and the transcriptional regulator spoIIID gene knockout mutant in sporulation. Anaerobe 2015; 33:55-63. [PMID: 25652599 DOI: 10.1016/j.anaerobe.2015.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/29/2015] [Accepted: 01/30/2015] [Indexed: 11/26/2022]
Abstract
Clostridium botulinum is a heat-resistant spore-forming bacterium that causes the serious paralytic illness botulism. Heat-resistant spores may cause food sanitation hazards and sporulation plays a central role in the survival of C. botulinum. We observed morphological changes and investigated the role of the transcriptional regulator SpoIIID in the sporulation of C. botulinum type B strain 111 in order to elucidate the molecular mechanism in C. botulinum. C. botulinum type B formed heat-resistant spores through successive morphological changes corresponding to those of Bacillus subtilis, a spore-forming model organism. An analysis of the spoIIID gene knockout mutant revealed that the transcriptional regulator SpoIIID contributed to heat-resistant spore formation by C. botulinum type B and activated the transcription of the sigK gene later during sporulation. Transcription of the spoIIID gene, which differed from that in B. subtilis and Clostridium difficile, was observed in the sigE gene knockout mutant of C. botulinum type B. An analysis of the sigF gene knockout mutant showed that the sporulation-specific sigma factor SigF was essential for transcription of the spoIIID gene in C. botulinum type B. These results suggest that the regulation of sporulation in C. botulinum is not similar to that in B. subtilis and other clostridia.
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Affiliation(s)
- Koji Hosomi
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Ritsuko Kuwana
- Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Hiromu Takamatsu
- Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Tomoko Kohda
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Shunji Kozaki
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Masafumi Mukamoto
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan.
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