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Lyu F, Yang D, Rao L, Liao X. Alanine and glutamate catabolism collaborate to ensure the success of Bacillus subtilis sporulation. Microbiol Res 2024; 286:127828. [PMID: 38991478 DOI: 10.1016/j.micres.2024.127828] [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: 06/11/2024] [Accepted: 06/30/2024] [Indexed: 07/13/2024]
Abstract
Sporulation as a typical bacterial differentiation process has been studied for decades. However, two crucial aspects of sporulation, (i) the energy sources supporting the process, and (ii) the maintenance of spore dormancy throughout sporulation, are scarcely explored. Here, we reported the crucial role of RocG-mediated glutamate catabolism in regulating mother cell lysis, a critical step for sporulation completion of Bacillus subtilis, likely by providing energy metabolite ATP. Notably, rocG overexpression resulted in an excessive ATP accumulation in sporulating cells, leading to adverse effects on future spore properties, e.g. increased germination efficiency, reduced DPA content, and lowered heat resistance. Additionally, we revealed that Ald-mediated alanine metabolism was highly related to the inhibition of premature germination and the maintenance of spore dormancy during sporulation, which might be achieved by decreasing the typical germinant L-alanine concentration in sporulating environment. Our data inferred that sporulation of B. subtilis was a highly orchestrated biological process requiring a delicate balance in diverse metabolic pathways, hence ensuring both the completion of sporulation and production of high-quality spores.
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Affiliation(s)
- Fengzhi Lyu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; National Engineering Research Center for Fruit and Vegetable Processing, Beijing, China; Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, Beijing, China
| | - Dong Yang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; National Engineering Research Center for Fruit and Vegetable Processing, Beijing, China; Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, Beijing, China
| | - Lei Rao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; National Engineering Research Center for Fruit and Vegetable Processing, Beijing, China; Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, Beijing, China.
| | - Xiaojun Liao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; National Engineering Research Center for Fruit and Vegetable Processing, Beijing, China; Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, Beijing, China
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2
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Fu Y, Liu X, Su Z, Wang P, Guo Q, Ma P. Arabinose Plays an Important Role in Regulating the Growth and Sporulation of Bacillus subtilis NCD-2. Int J Mol Sci 2023; 24:17472. [PMID: 38139303 PMCID: PMC10744016 DOI: 10.3390/ijms242417472] [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: 10/20/2023] [Revised: 11/22/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
A microbial fungicide developed from Bacillus subtilis NCD-2 has been registered for suppressing verticillium wilt in crops in China. Spores are the main ingredient of this fungicide and play a crucial role in suppressing plant disease. Therefore, increasing the number of spores of strain NCD-2 during fermentation is important for reducing the cost of the fungicide. In this study, five kinds of carbon sources were found to promote the metabolism of strain NCD-2 revealed via Biolog Phenotype MicroArray (PM) technology. L-arabinose showed the strongest ability to promote the growth and sporulation of strain NCD-2. L-arabinose increased the bacterial concentration and the sporulation efficiency of strain NCD-2 by 2.04 times and 1.99 times compared with D-glucose, respectively. Moreover, L-arabinose significantly decreased the autolysis of strain NCD-2. Genes associated with arabinose metabolism, sporulation, spore resistance to heat, and spore coat formation were significantly up-regulated, and genes associated with sporulation-delaying protein were significantly down-regulated under L-arabinose treatment. The deletion of msmX, which is involved in arabinose transport in the Bacillus genus, decreased growth and sporulation by 53.71% and 86.46% compared with wild-type strain NCD-2, respectively. Complementing the mutant strain by importing an intact msmX gene restored the strain's growth and sporulation.
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Affiliation(s)
- Yifan Fu
- College of Plant Protection, Agricultural University of Hebei, Baoding 071000, China;
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
| | - Xiaomeng Liu
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
| | - Zhenhe Su
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
| | - Peipei Wang
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
| | - Qinggang Guo
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
| | - Ping Ma
- Key Laboratory of IPM on Crops in Northern Region of North China, Integrated Pest Management Innovation Centre of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Ministry of Agriculture and Rural Affairs of China, Baoding 071000, China; (X.L.); (Z.S.); (P.W.)
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KUWANA RITSUKO, YAMAZAWA RYUJI, ITO KIYOSHI, TAKAMATSU HIROMU. The Study of Diversity in Sporulation among Closely Genetically Related <i>Bacillus cereus</i> Strains. Biocontrol Sci 2022; 27:143-151. [DOI: 10.4265/bio.27.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
| | | | - KIYOSHI ITO
- Faculty of Pharmaceutical Sciences, Setsunan University
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Rodríguez M A, Rache LY, Brijaldo MH, Romanelli GP, Luque R, Martinez JJ. Biocatalytic transformation of furfural into furfuryl alcohol using resting cells of Bacillus cereus. Catal Today 2021. [DOI: 10.1016/j.cattod.2021.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Jessberger N, Dietrich R, Granum PE, Märtlbauer E. The Bacillus cereus Food Infection as Multifactorial Process. Toxins (Basel) 2020; 12:E701. [PMID: 33167492 PMCID: PMC7694497 DOI: 10.3390/toxins12110701] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
The ubiquitous soil bacterium Bacillus cereus presents major challenges to food safety. It is responsible for two types of food poisoning, the emetic form due to food intoxication and the diarrheal form emerging from food infections with enteropathogenic strains, also known as toxico-infections, which are the subject of this review. The diarrheal type of food poisoning emerges after production of enterotoxins by viable bacteria in the human intestine. Basically, the manifestation of the disease is, however, the result of a multifactorial process, including B. cereus prevalence and survival in different foods, survival of the stomach passage, spore germination, motility, adhesion, and finally enterotoxin production in the intestine. Moreover, all of these processes are influenced by the consumed foodstuffs as well as the intestinal microbiota which have, therefore, to be considered for a reliable prediction of the hazardous potential of contaminated foods. Current knowledge regarding these single aspects is summarized in this review aiming for risk-oriented diagnostics for enteropathogenic B. cereus.
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Affiliation(s)
- Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Richard Dietrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Per Einar Granum
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, P.O. Box 5003 NMBU, 1432 Ås, Norway;
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
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Recent Advances in the Physiology of Spore Formation for Bacillus Probiotic Production. Probiotics Antimicrob Proteins 2020; 11:731-747. [PMID: 30515722 DOI: 10.1007/s12602-018-9492-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Spore-forming probiotic bacteria have received a wide and constantly increasing scientific and commercial interest. Among them, Bacillus species are the most studied and well-characterized Gram-positive bacteria. The use of bacilli as probiotic products is expanding especially rapidly due to their inherent ability to form endospores with unique survivability and tolerance to extreme environments and to produce a large number of valuable metabolites coupled with their bio-therapeutic potential demonstrating immune stimulation, antimicrobial activities and competitive exclusion. Ease of Bacillus spp. production and stability during processing and storage make them a suitable candidate for commercial manufacture of novel foods or dietary supplements for human and animal feeds for livestock, especially in the poultry and aquaculture industries. Therefore, the development of low-cost and competitive technologies for the production of spore-forming probiotic bacteria through understanding physiological peculiarities and mechanisms determining the growth and spore production by Bacillus spp. became necessary. This review summarizes the recent literature and our own data on the physiology of bacilli growth and spore production in the submerged and solid-state fermentation conditions, focusing on the common characteristics and unique properties of individual bacteria as well as on several approaches providing enhanced spore formation.
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7
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Intracellular response of Bacillus natto in response to different oxygen supply and its influence on menaquinone-7 biosynthesis. Bioprocess Biosyst Eng 2019; 42:817-827. [DOI: 10.1007/s00449-019-02085-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/27/2019] [Indexed: 10/27/2022]
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8
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Bressuire-Isoard C, Broussolle V, Carlin F. Sporulation environment influences spore properties in Bacillus: evidence and insights on underlying molecular and physiological mechanisms. FEMS Microbiol Rev 2018; 42:614-626. [DOI: 10.1093/femsre/fuy021] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 05/16/2018] [Indexed: 02/07/2023] Open
Affiliation(s)
- Christelle Bressuire-Isoard
- UMR408 SQPOV “Sécurité et Qualité des Produits d'Origine Végétale”, INRA–Avignon Université, Centre de Recherche PACA, CS40509, Site Agroparc, 84914 Avignon Cedex 9, France
| | - Véronique Broussolle
- UMR408 SQPOV “Sécurité et Qualité des Produits d'Origine Végétale”, INRA–Avignon Université, Centre de Recherche PACA, CS40509, Site Agroparc, 84914 Avignon Cedex 9, France
| | - Frédéric Carlin
- UMR408 SQPOV “Sécurité et Qualité des Produits d'Origine Végétale”, INRA–Avignon Université, Centre de Recherche PACA, CS40509, Site Agroparc, 84914 Avignon Cedex 9, France
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9
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Substratum attachment location and biofilm formation by Bacillus cereus strains isolated from different sources: Effect on total biomass production and sporulation in different growth conditions. Food Control 2017. [DOI: 10.1016/j.foodcont.2017.02.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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10
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‘Omics’ for microbial food stability: Proteomics for the development of predictive models for bacterial spore stress survival and outgrowth. Int J Food Microbiol 2017; 240:11-18. [DOI: 10.1016/j.ijfoodmicro.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/03/2016] [Accepted: 05/06/2016] [Indexed: 12/25/2022]
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11
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Systematic development and optimization of chemically defined medium supporting high cell density growth of Bacillus coagulans. Appl Microbiol Biotechnol 2016; 100:8121-34. [PMID: 27262567 DOI: 10.1007/s00253-016-7644-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/09/2016] [Accepted: 05/12/2016] [Indexed: 10/21/2022]
Abstract
With determined components and experimental reducibility, the chemically defined medium (CDM) and the minimal chemically defined medium (MCDM) are used in many metabolism and regulation studies. This research aimed to develop the chemically defined medium supporting high cell density growth of Bacillus coagulans, which is a promising producer of lactic acid and other bio-chemicals. In this study, a systematic methodology combining the experimental technique with flux balance analysis (FBA) was proposed to design and simplify a CDM. The single omission technique and single addition technique were employed to determine the essential and stimulatory compounds, before the optimization of their concentrations by the statistical method. In addition, to improve the growth rationally, in silico omission and addition were performed by FBA based on the construction of a medium-size metabolic model of B. coagulans 36D1. Thus, CDMs were developed to obtain considerable biomass production of at least five B. coagulans strains, in which two model strains B. coagulans 36D1 and ATCC 7050 were involved.
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12
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Abbas AA, Planchon S, Jobin M, Schmitt P. Absence of oxygen affects the capacity to sporulate and the spore properties of Bacillus cereus. Food Microbiol 2014; 42:122-31. [DOI: 10.1016/j.fm.2014.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 01/28/2014] [Accepted: 03/06/2014] [Indexed: 11/16/2022]
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13
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Abbas AA, Planchon S, Jobin M, Schmitt P. A new chemically defined medium for the growth and sporulation of Bacillus cereus strains in anaerobiosis. J Microbiol Methods 2014; 105:54-8. [PMID: 25019521 DOI: 10.1016/j.mimet.2014.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 07/03/2014] [Accepted: 07/03/2014] [Indexed: 11/19/2022]
Abstract
A new chemically defined liquid medium, MODS, was developed for the aerobic growth and anaerobic growth and sporulation of Bacillus cereus strains. The comparison of sporulation capacity of 18 strains of B. cereus has shown effective growth and spore production in anaerobiosis..
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Affiliation(s)
- Amina Aicha Abbas
- INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, "F-84000 Avignon, France; Université d'Avignon et des Pays de Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, France
| | - Stella Planchon
- INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, "F-84000 Avignon, France; Université d'Avignon et des Pays de Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, France
| | - Michel Jobin
- INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, "F-84000 Avignon, France; Université d'Avignon et des Pays de Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, France
| | - Philippe Schmitt
- INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, "F-84000 Avignon, France; Université d'Avignon et des Pays de Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, France.
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Toxin producing Bacillus cereus persist in ready-to-reheat spaghetti Bolognese mainly in vegetative state. Int J Food Microbiol 2013; 167:236-43. [PMID: 24129156 DOI: 10.1016/j.ijfoodmicro.2013.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 07/31/2013] [Accepted: 09/04/2013] [Indexed: 12/26/2022]
Abstract
The potential of Bacillus cereus to cause a diarrheal toxico-infection is related to its ability to perform de novo enterotoxin production in the small intestine. A prerequisite for this is presence of sufficient numbers of B. cereus that have survived gastro-intestinal passage. It is known that the percentage of survival is much smaller for vegetative cells in comparison to spores and it is therefore important to know the state in which B. cereus is ingested. The results of the current study performed on twelve B. cereus strains, comprising both diarrheal and emetic type, indicate that exposure via contaminated foods mainly concerns vegetative cells. Inoculated vegetative cells grew to high counts, with the growth dynamic depending on the storage temperature. At 28 °C growth to high counts resulted in spore formation, in general, after 1 day of storage. One strain was an exception, producing spores only after 16 days. At 12 °C obtained high counts did not result in spore formation for 11 of 12 tested strains after two weeks of storage. The highest counts and time to sporulation were different between strains, but no difference was observed on the group level of diarrheal and emetic strains. The spore counts were always lower than vegetative cell counts and occurred only when food was obviously sensory spoiled (visual and odor evaluation). Similar observations were made with food inoculated with B. cereus spores instead of vegetative cells. Although the prospect of consuming spores was found very weak, the numbers of vegetative B. cereus cells were high enough, without obvious sensory deviation, to survive in sufficient level to cause diarrheal toxico-infection.
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van der Voort M, Abee T. Sporulation environment of emetic toxin-producing Bacillus cereus
strains determines spore size, heat resistance and germination capacity. J Appl Microbiol 2013; 114:1201-10. [DOI: 10.1111/jam.12118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/10/2012] [Accepted: 12/19/2012] [Indexed: 11/30/2022]
Affiliation(s)
- M. van der Voort
- Top Institute Food and Nutrition (TIFN); Wageningen The Netherlands
- Laboratory of Food Microbiology; Wageningen University and Research Centre; Wageningen The Netherlands
- Present address: Laboratory of Phytopathology; Wageningen University and Research Centre; PO box 8025 Wageningen 6700 EE The Netherlands
| | - T. Abee
- Top Institute Food and Nutrition (TIFN); Wageningen The Netherlands
- Laboratory of Food Microbiology; Wageningen University and Research Centre; Wageningen The Netherlands
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Sella SRBR, Gouvea PM, Gomes VF, Vandenberghe LPS, Minozzo JC, Soccol CR. Glycerol-based sterilization bioindicator system from Bacillus atrophaeus: development, performance evaluation, and cost analysis. Appl Microbiol Biotechnol 2012; 97:1031-42. [PMID: 22911095 DOI: 10.1007/s00253-012-4350-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 07/30/2012] [Accepted: 07/31/2012] [Indexed: 10/28/2022]
Abstract
The development of new value-added applications for glycerol is of worldwide interest because of the environmental and economic problems that may be caused by an excess of glycerol generated from biodiesel production. A novel use of glycerol as a major substrate for production of a low-cost sterilization biological indicator system (BIS; spores on a carrier plus a recovery medium) was investigated. A sequential experimental design strategy was applied for product development and optimization. The proposed recovery medium enables germination and outgrowth of heat-damaged spores, promoting a D (160 °C) value of 6.6 ± 0.1 min. Bacillus atrophaeus spores production by solid-state fermentation reached a 2.3 ± 1.2 × 10(8) CFU/g dry matter. Sporulation kinetics results allowed this process to be restricted in 48 h. Germination kinetics demonstrated the visual identification of nonsterile BIS within 24 h. Performance evaluation of the proposed BIS against dry-heat and ethylene oxide sterilization showed compliance with the regulatory requirements. Cost breakdowns were from 41.8 (quality control) up to 72.8 % (feedstock). This is the first report on sterilization BIS production that uses glycerol as a sole carbon source, with significant cost reduction and the profitable use of a biodiesel byproduct.
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Affiliation(s)
- Sandra R B R Sella
- Production and Research Centre of Immunobiological Products, Parana State Department of Health, Av. São Roque, 716, Piraquara, PR, 83302-200, Brazil.
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Sella SRBR, Guizelini BP, Gouvea PM, Figueiredo LFM, Ribeiro CAO, Vandenberghe LPS, Minozzo JC, Soccol CR. Relations between phenotypic changes of spores and biofilm production by Bacillus atrophaeus ATCC 9372 growing in solid-state fermentation. Arch Microbiol 2012; 194:815-25. [DOI: 10.1007/s00203-012-0815-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/11/2012] [Accepted: 04/06/2012] [Indexed: 11/30/2022]
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Effects of the SpoVT regulatory protein on the germination and germination protein levels of spores of Bacillus subtilis. J Bacteriol 2012; 194:3417-25. [PMID: 22522895 DOI: 10.1128/jb.00504-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus subtilis isolates lacking the SpoVT protein, which regulates gene expression in developing forespores, gave spores that released their dipicolinic acid (DPA) via germinant receptor (GR)-dependent germination more rapidly than wild-type spores. Non-GR-dependent germination via dodecylamine was more rapid with spoVT spores, but germination via Ca-DPA was slower. The effects of a spoVT mutation on spore germination were seen with spores made in rich and poor media, and levels of SpoVT-LacZ were elevated 2-fold in poor-medium spores; however, elevated SpoVT levels were not the only cause of the slower GR-dependent germination of poor-medium spores. The spoVT spores had ≥5-fold higher GerA GR levels, ∼2-fold elevated GerB GR levels, wild-type levels of a GerK GR subunit and the GerD protein required for normal GR-dependent germination, ∼2.5-fold lower levels of the SpoVAD protein involved in DPA release in spore germination, and 30% lower levels of DNA protective α/β-type small, acid-soluble spore proteins. With one exception, the effects on protein levels in spoVT spores are consistent with the effects of SpoVT on forespore transcription. The spoVT spores were also more sensitive to UV radiation and outgrew slowly. While spoVT spores' elevated GR levels were consistent with their more rapid GR-dependent germination, detailed analysis of the results suggested that there is another gene product crucial for GR-dependent spore germination that is upregulated in the absence of SpoVT. Overall, these results indicate that SpoVT levels during spore formation have a major impact on the germination and the resistance of the resultant spores.
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Effects of sporulation conditions on the germination and germination protein levels of Bacillus subtilis spores. Appl Environ Microbiol 2012; 78:2689-97. [PMID: 22327596 DOI: 10.1128/aem.07908-11] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Bacillus subtilis spores prepared in rich medium germinated faster with nutrient germinants than poor-medium spores as populations in liquid and multiple individual spores on a microscope slide. Poor-medium spores had longer average lag times between mixing of spores with nutrient germinants and initiation of Ca-dipicolinic acid (CaDPA) release. Rich-medium spores made at 37°C germinated slightly faster with nutrient germinants than 23°C spores in liquid, but not when spores germinated on a slide. The difference in germination characteristics of these spore populations in liquid was paralleled by changes in expression levels of a transcriptional lacZ fusion to the gerA operon, encoding a germinant receptor (GR). Levels of GR subunits were 3- to 8-fold lower in poor-medium spores than rich-medium spores and 1.6- to 2-fold lower in 23°C spores than 37°C spores, and levels of the auxiliary germination protein GerD were 3.5- to 4-fold lower in poor medium and 23°C spores. In contrast, levels of another likely germination protein, SpoVAD, were similar in all these spores. These different spores germinated similarly with CaDPA, and poor-medium and 23°C spores germinated faster than rich-medium and 37°C spores, respectively, with dodecylamine. Since spore germination with CaDPA and dodecylamine does not require GerD or GRs, these results indicate that determinants of rates of nutrient germination of spores prepared differently are primarily the levels of the GRs that bind nutrient germinants and trigger germination and secondarily the levels of GerD.
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Løvdal IS, Hovda MB, Granum PE, Rosnes JT. Promoting Bacillus cereus spore germination for subsequent inactivation by mild heat treatment. J Food Prot 2011; 74:2079-89. [PMID: 22186048 DOI: 10.4315/0362-028x.jfp-11-292] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sublethal heat treatment may activate dormant spores and thereby potentiate the conversion of spores to vegetative cells. As the germinated spore is known to possess lower heat resistance than its dormant counterpart, it has been postulated that double heat treatment, i.e., spore heat activation followed by germination and then by heat inactivation, can be used to control spores in foods. Production of refrigerated processed foods of extended durability often includes more than one heat treatment of the food components. This work simulates conventional heat treatment procedures and evaluates double heat treatment as a method to improve spore control in model food matrixes of meat broth and cream sauce. Bacillus cereus NVH 1230-88 spores were supplemented in food model matrixes and heat activated at 70°C and then heat inactivated at 80 or 90°C. The samples were held at 29 to 30°C for 1 h between primary and secondary heat treatments, to allow spore germination. Nutrients naturally present in the food matrixes, e.g., amino acids and inosine, could act as germinants that induce germination. The levels of germinants could be too low to produce effective germination within 1 h. Following primary heat treatment, some samples were therefore supplemented with a combination of L-alanine and inosine, a germinant mixture known to be effective for B. cereus spores. In both matrixes, a combination of double heat treatment (heat activation, germination, and inactivation) and addition of germinants gave a reduction in spore counts equivalent to or greater than that obtained with a single heat treatment for 12 min at 90°C. Addition of germinants was essential to induce effective germination in cream sauce during 1 h at 29 to 30°C, and germinants were therefore a crucial supplement to obtain an effect of double heat treatment in this matrix. These data will be valuable when setting up temperature-time-germinant combinations for an optimized spore reduction in mild-heat-treated foods.
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Affiliation(s)
- Irene Stranden Løvdal
- Nofima AS, Department of Process Technology, P.O. Box 8034, N-4068 Stavanger, Norway
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21
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Scaria J, Janvilisri T, Fubini S, Gleed RD, McDonough SP, Chang YF. Clostridium difficile transcriptome analysis using pig ligated loop model reveals modulation of pathways not modulated in vitro. J Infect Dis 2011; 203:1613-20. [PMID: 21592991 DOI: 10.1093/infdis/jir112] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A pig ligated loop model was used to analyze the in vivo transcriptome response of Clostridium difficile. Bacterial RNA from the loops was retrieved at different times and was used for microarray analysis. Several virulence-associated genes and genes involved in sporulation cascade were differentially expressed (DE). In concordance with observed upregulation of toxin genes in microarray, enzyme-linked immunosorbent assay estimation of total toxin showed high amounts of toxin in the loops. Several genes that were absent in primary annotation of C. difficile 630 but annotated in a secondary annotation were found to be DE. Pathway comparison of DE genes in vitro and in vivo showed that when several pathways were expressed in all conditions, several of the C. difficile pathways were uniquely expressed only in vivo. The pathways observed to be modulated only in this study could be targets of new therapeutic agents against C. difficile infection.
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Affiliation(s)
- Joy Scaria
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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22
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Bacterial spores in food: how phenotypic variability complicates prediction of spore properties and bacterial behavior. Curr Opin Biotechnol 2011; 22:180-6. [DOI: 10.1016/j.copbio.2010.11.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 11/12/2010] [Accepted: 11/15/2010] [Indexed: 11/21/2022]
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23
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Origin of bacterial spores contaminating foods. Food Microbiol 2011; 28:177-82. [DOI: 10.1016/j.fm.2010.07.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 07/07/2010] [Accepted: 07/08/2010] [Indexed: 11/22/2022]
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24
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Carlin F, Brillard J, Broussolle V, Clavel T, Duport C, Jobin M, Guinebretière MH, Auger S, Sorokine A, Nguyen-Thé C. Adaptation of Bacillus cereus, an ubiquitous worldwide-distributed foodborne pathogen, to a changing environment. Food Res Int 2010. [DOI: 10.1016/j.foodres.2009.10.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Garcia D, der Voort MV, Abee T. Comparative analysis of Bacillus weihenstephanensis KBAB4 spores obtained at different temperatures. Int J Food Microbiol 2010; 140:146-53. [DOI: 10.1016/j.ijfoodmicro.2010.04.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 03/29/2010] [Accepted: 04/01/2010] [Indexed: 10/19/2022]
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26
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Abee T, Groot MN, Tempelaars M, Zwietering M, Moezelaar R, van der Voort M. Germination and outgrowth of spores of Bacillus cereus group members: diversity and role of germinant receptors. Food Microbiol 2010; 28:199-208. [PMID: 21315974 DOI: 10.1016/j.fm.2010.03.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 03/19/2010] [Accepted: 03/25/2010] [Indexed: 11/26/2022]
Abstract
Bacillus cereus is a gram-positive, facultative anaerobic, endospore-forming toxicogenic human pathogen. Endospores are highly specialized, metabolically dormant cell types that are resistant to extreme environmental conditions, including heat, dehydration and other physical stresses. B. cereus can enter a range of environments, and can in its spore form, survive harsh conditions. If these conditions become favorable, spores can germinate and grow out and reach considerable numbers in a range of environments including processed foods. Certainly the last decade, when consumer preferences have shifted to mildly processed food, new opportunities arose for spore-forming spoilage and pathogenic organisms. Only rigorous methods have been shown to be capable of destroying all spores present in food, thus a shift toward e.g., milder heat preservation strategies, may result in low but significant amounts of viable spores in food products. Hence, the need for a mild spore destruction strategy is eminent including control of spore outgrowth. Consequently, there is a large interest in triggering spore germination in foodstuffs, since germinated spores have lost the extreme resistance of dormant spores and are relatively easy to kill. Another option could be to prevent germination so that no dangerous levels can be reached. This contribution will focus on germination and outgrowth characteristics of B. cereus and other members of the B. cereus group, providing an overview of the niches these spore-formers can occupy, the signals that trigger germination, and how B. cereus copes with these wake-up calls in different environments including foods, during food processing and upon interaction with the human host.
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Affiliation(s)
- Tjakko Abee
- TI Food and Nutrition (TIFN), Wageningen, The Netherlands.
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27
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Blel W, Legentilhomme P, Le Gentil-Lelièvre C, Faille C, Legrand J, Bénézech T. Cleanability study of complex geometries: Interaction between B. cereus spores and the different flow eddies scales. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2009.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Stecchini M, Spaziani M, Torre MD, Pacor S. Bacillus cereuscell and spore properties as influenced by the micro-structure of the medium. J Appl Microbiol 2009; 106:1838-48. [DOI: 10.1111/j.1365-2672.2009.04162.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Laflamme C, Gendron L, Turgeon N, Filion G, Ho J, Duchaine C. In situ detection of antibiotic-resistance elements in single Bacillus cereus spores. Syst Appl Microbiol 2009; 32:323-33. [PMID: 19446419 DOI: 10.1016/j.syapm.2009.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/12/2009] [Accepted: 03/18/2009] [Indexed: 10/20/2022]
Abstract
Rapid detection of Bacillus spores is a challenging task in food and defense industries. In situ labeling of spores would be advantageous for detection by automated systems based on single-cell analysis. Determination of antibiotic-resistance genes in bacterial spores using in situ labeling has never been developed. Most of the in situ detection schemes employ techniques such as fluorescence in situ hybridization (FISH) that target the naturally amplified ribosomal RNA (rRNA). However, the majority of antibiotic-resistance genes has a plasmidic or chromosomal origin and is present in low copy numbers in the cell. The main challenge in the development of low-target in situ detection in spores is the permeabilization procedure and the signal amplification required for detection. This study presents permeabilization and in situ signal amplification protocols, using Bacillus cereus spores as a model, in order to detect antibiotic-resistance genes. The permeabilization protocol was designed based on the different layers of the Bacillus spore. Catalyzed reporter deposition (CARD)-FISH and in situ polymerase chain reaction (PCR) were used as signal amplification techniques. B. cereus was transformed with the high copy number pC194 and low copy number pMTL500Eres plasmids in order to induce resistance to chloramphenicol and erythromycin, respectively. In addition, a rifampicin-resistant B. cereus strain, conferred by a single-nucleotide polymorphism (SNP) in the chromosome, was used. Using CARD-FISH, only the high copy number plasmid pC194 was detected. On the other hand, in situ PCR gave positive results in all tested instances. This study demonstrated that it was feasible to detect antibiotic-resistance genes in Bacillus spores using in situ techniques. In addition, in situ PCR has been shown to be more sensitive and more applicable than CARD-FISH in detecting low copy targets.
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Affiliation(s)
- Christian Laflamme
- Institut Universitaire de cardiologie et de pneumologie, Centre de recherche, Hôpital Laval, Université Laval, 2725 Chemin Ste-Foy, Ste-Foy, Québec, Canada G1V 4G5
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Filion G, Laflamme C, Turgeon N, Ho J, Duchaine C. Permeabilization and hybridization protocols for rapid detection of Bacillus spores using fluorescence in situ hybridization. J Microbiol Methods 2009; 77:29-36. [DOI: 10.1016/j.mimet.2008.12.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 12/19/2008] [Accepted: 12/19/2008] [Indexed: 11/17/2022]
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31
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Sella SRBR, Guizelini BP, Vandenberghe LPS, Medeiros ABP, Soccol CR. Bioindicator production with Bacillus atrophaeus' thermal-resistant spores cultivated by solid-state fermentation. Appl Microbiol Biotechnol 2009; 82:1019-26. [PMID: 19039586 DOI: 10.1007/s00253-008-1768-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 10/23/2008] [Accepted: 10/25/2008] [Indexed: 10/21/2022]
Abstract
Bacillus atrophaeus' spores are used in the preparation of bioindicators to monitor the dry heat, ethylene oxide, and plasma sterilization processes and in tests to assess sterilizing products. Earlier production methods involved culture in chemically defined medium to support sporulation with the disadvantage of requiring an extended period of time (14 days) besides high cost of substrates. The effect of cultivation conditions by solid-state fermentation (SSF) was investigated aiming at improving the cost-productivity relation. Initial SSF parameters such as the type of substrate were tested. Process optimization was carried out using factorial experimental designs and response surface methodology in which the influence of different variables--particle size, moisture content, incubation time, pH, inoculum size, calcium sources, and medium composition--was studied. The results have suggested that soybean molasses and sugarcane bagasse are potential substrate and support, respectively, contributing to a 5-day reduction in incubation time. Variables which presented significant effects and optimum values were mean particle size (1.0 mm), moisture content (93%), initial substrate pH (8.0), and water as a solution base. The high-yield spore production was about 3 logs higher than the control and no significant difference in dry heat resistance was observed.
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Affiliation(s)
- Sandra Regina B R Sella
- Production and Research Centre of Immunobiological Products, State Department of Health, Piraquara, Paraná, Brazil
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32
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Ouhib-Jacobs O, Lindley ND, Schmitt P, Clavel T. Fructose and glucose mediates enterotoxin production and anaerobic metabolism of Bacillus cereus ATCC14579(T). J Appl Microbiol 2009; 107:821-9. [PMID: 19302315 DOI: 10.1111/j.1365-2672.2009.04254.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To determine the effects of carbohydrates on Bacillus cereus ATCC14579(T) anaerobic metabolism and enterotoxin production in amino acids rich medium. METHODS AND RESULTS Bacillus cereus anaerobic growth on different carbohydrates (glucose, fructose, sucrose or glucose-fructose mixture) was examined in synthetic mMOD medium under continuous cultures (mu = 0.2 h(-1)). Fermentation end-products, flux partitioning at each key branch points of the mixed acid pathway and consumption or production of amino acids were determined. On both fructose and sucrose, ATP production was favoured via acetate production from acetyl-CoA. In addition, amino acids present in the growth medium showed significant variations with high consumption of serine and net production of glutamate and alanine on some or all sugars. Enterotoxins Hbl and Nhe production was high during growth on fructose (or mixtures involving a fructose moiety). CONCLUSIONS Fructose was identified as a key sugar influencing anaerobic metabolism and toxin production of B. cereus. SIGNIFICANCE AND IMPACT OF THE STUDY The physiological differences associated with the fermentation of the various carbohydrates clearly modify toxinogenesis indicating that the risk of foodborne pathogens is to some extent dependent upon the prevailing nutritional environment.
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Affiliation(s)
- O Ouhib-Jacobs
- Université d'Avignon et des Pays de Vaucluse, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, Avignon, France
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33
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Buhr T, McPherson D, Gutting B. Analysis of broth-culturedBacillus atrophaeusandBacillus cereusspores. J Appl Microbiol 2008; 105:1604-13. [DOI: 10.1111/j.1365-2672.2008.03899.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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34
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Turgeon N, Laflamme C, Ho J, Duchaine C. Evaluation of the plasmid copy number in B. cereus spores, during germination, bacterial growth and sporulation using real-time PCR. Plasmid 2008; 60:118-24. [DOI: 10.1016/j.plasmid.2008.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 05/09/2008] [Accepted: 05/12/2008] [Indexed: 11/30/2022]
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35
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Aronson AI, Hu H. The response to a specific germinant by Bacillus anthracis spores in primary mouse macrophages is modulated by a protein encoded on the pXO1 plasmid. Arch Microbiol 2008; 190:539-46. [PMID: 18654763 DOI: 10.1007/s00203-008-0403-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Revised: 06/05/2008] [Accepted: 06/18/2008] [Indexed: 11/30/2022]
Abstract
A Bacillus anthracis Sterne pXO1 plasmid-encoded protein designated Cot43 was found in coat extracts of purified spores. Cot43 is a tetratricopeptide repeat domain protein related to those which function as phosphatases in the sporulation phosphorelay and as regulators of competence and pathogenic factors. The synthesis of Cot43 began in the late exponential phase downstream from a sigmaA promoter (as mapped by RACE) and it was present at least until the formation of phase white endospores. There was specificity in the association of Cot43 with B. anthracis spores since Bacillus cereus producing Cot43 from a cloned gene had very little of this protein in spore coat extracts. In addition, Cot43 was synthesized by B. anthracis cells to the same extent in glucose-yeast extract and nutrient sporulation media, but was essentially absent from spores formed in the former. L-histidine is an important germinant for B. anthracis spores in macrophages, Spores produced by a mutant with a disruption of cot43 germinated in response to L-histidine both in vitro and within primary mouse macrophages earlier and more extensively than Sterne strain spores. The germination delay due to the presence of Cot43 would enhance spore survival and thus increase the chances for a successful infection.
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Affiliation(s)
- Arthur I Aronson
- Department of Biological Sciences, Purdue University, W. Lafayette, IN 47907, USA.
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36
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Selection and Optimization of Bacillus atrophaeus Inoculum Medium and its Effect on Spore Yield and Thermal Resistance. Appl Biochem Biotechnol 2008; 151:380-92. [DOI: 10.1007/s12010-008-8206-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 03/07/2008] [Indexed: 11/26/2022]
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37
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Hornstra LM, de Vries YP, de Vos WM, Abee T. Influence of sporulation medium composition on transcription of ger operons and the germination response of spores of Bacillus cereus ATCC 14579. Appl Environ Microbiol 2006; 72:3746-9. [PMID: 16672527 PMCID: PMC1472338 DOI: 10.1128/aem.72.5.3746-3749.2006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus cereus ATCC 14579 endospores were produced in Y1 medium, a nutrient-rich, chemically defined sporulation medium, and in modified G medium, containing low amounts of nutrients. The average transcription level of the seven ger operons per cell was 3.5 times higher in Y1 medium, and the spores grown in this medium showed an enhanced germination response.
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Affiliation(s)
- Luc M Hornstra
- Laboratory of Food Microbiology, Wageningen University, Bomenweg 2, 6703 HD Wageningen, The Netherlands
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38
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Yadava P, Zhang C, Sun J, Hughes JA. Antimicrobial activities of human beta-defensins against Bacillus species. Int J Antimicrob Agents 2006; 28:132-7. [PMID: 16797165 DOI: 10.1016/j.ijantimicag.2006.02.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 02/19/2006] [Indexed: 11/17/2022]
Abstract
Natural defences in the human body function to protect us from numerous environmental toxins and exposure to potential harmful biological agents. An important frontline defence is antimicrobial peptides. These peptides occur at environmental interfaces and serve to limit bacterial invasion. There has been little work comparing specific peptides as potential antimicrobial compounds. In this study, we evaluated the antimicrobial activity of peptides from the human beta-defensin (HBD) family against four species of Bacillus, chosen as models for Bacillus anthracis, a potential bioweapon. The impact of peptide concentration, sequence and protein binding was evaluated on their biological activity. The results indicated that HBD-3 was the most biologically active against Bacillus subtilis and Bacillus licheniformis, whilst HBD-2 was found to be most active against Bacillus cereus and Bacillus thuringiensis. Moreover, the antimicrobial activity of the peptides was directly related to peptide concentration and indirectly related to albumin concentration (i.e. protein binding).
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Affiliation(s)
- Preeti Yadava
- Department of Pharmaceutics, Box 100494, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610, USA
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39
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de Vries YP, Hornstra LM, Atmadja RD, Schaik WV, de Vos WM, Abee T. Deletion ofsigBinBacillus cereusaffects spore properties. FEMS Microbiol Lett 2005; 252:169-73. [PMID: 16171954 DOI: 10.1016/j.femsle.2005.08.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Revised: 08/17/2005] [Accepted: 08/29/2005] [Indexed: 11/25/2022] Open
Abstract
In Bacillus cereus and other gram-positive bacteria the alternative sigma factor sigma(B) is an important regulator of the stress response. Deletion of the sigB gene generally leads to a stress-sensitive phenotype of vegetative cells. In this study, we describe the effect of the deletion of the sigB gene in B. cereus on spore properties. In particular, spores of the sigB deletion mutant showed a defect in germination upon exposure to the germinants alanine and inosine.
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Affiliation(s)
- Ynte P de Vries
- Wageningen Centre for Food Sciences, Bomenweg 2, 6703 HD Wageningen, The Netherlands
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