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Soni A, Brightwell G. Effect of novel and conventional food processing technologies on Bacillus cereus spores. ADVANCES IN FOOD AND NUTRITION RESEARCH 2023; 108:265-287. [PMID: 38461001 DOI: 10.1016/bs.afnr.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
This chapter provides a summary of the effect of thermal and non-thermal processing technologies on Bacillus cereus spores, a well-known pathogenic bacterium associated with foodborne illnesses. B. cereus has been frequently detected in rice, milk products, infant food, liquid eggs products and meat products all over the world. This Gram positive, rod-shaped, facultative anaerobe can produce endospores that can withstand pasteurization, UV radiation, and chemical reagents commonly used for sanitization. B. cereus spores can germinate into vegetative cells that can produce toxins. The conventional regime for eliminating spores from food is retorting which uses the application of high temperature (121 °C). However, at this temperature, there could be a significant amount of loss in the organoleptic and functional qualities of the food components, especially proteins. This leads to the research on the preventive measures against germination and if possible, to reduce the resistance before using a non-thermal technology (temperatures less than retorting-121 °C) for inactivation. This chapter reviews the development and success of several food processing technologies in their ability to inactivate B. cereus spores in food.
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Affiliation(s)
- Aswathi Soni
- Food System Integrity, Smart Foods and Bioproducts, AgResearch Ltd., Hopkirk Research Institute, Massey University, Palmerston North, New Zealand.
| | - Gale Brightwell
- Food System Integrity, Smart Foods and Bioproducts, AgResearch Ltd., Hopkirk Research Institute, Massey University, Palmerston North, New Zealand; New Zealand Food Safety Science and Research Centre, Massey University Manawatu (Turitea), Palmerston North, New Zealand
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2
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Biermann R, Beutel S. Endospore production of Bacillus spp. for industrial use. Eng Life Sci 2023; 23:e2300013. [PMID: 37970521 PMCID: PMC10630785 DOI: 10.1002/elsc.202300013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/02/2023] [Accepted: 10/05/2023] [Indexed: 11/17/2023] Open
Abstract
The increased occurrence of antibiotic resistance and the harmful use of pesticides are a major problem of modern times. A ban on the use of antibiotics as growth promoters in animal breeding has put a focus on the probiotics market. Probiotic food supplements are versatile and show promising results in animal and human nutrition. Chemical pesticides can be substituted by biopesticides, which are very effective against various pests in plants due to increased research. What these fields have in common is the use of spore-forming bacteria. The endospore-forming Bacillus spp. belonging to this group offer an effective solution to the aforementioned problems. Therefore, the biotechnological production of sufficient qualities of such endospores has become an innovative and financially viable field of research. In this review, the production of different Bacillus spp. endospores will be reviewed. For this purpose, the media compositions, cultivation conditions and bioprocess optimization methods of the last 20 years are presented and reflected.
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Affiliation(s)
- Riekje Biermann
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
| | - Sascha Beutel
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
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3
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Biermann R, Rösner L, Beyer L, Niemeyer L, Beutel S. Bioprocess development for endospore production by Bacillus coagulans using an optimized chemically defined medium. Eng Life Sci 2023; 23:e2300210. [PMID: 37795343 PMCID: PMC10545977 DOI: 10.1002/elsc.202300210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/09/2023] [Accepted: 09/08/2023] [Indexed: 10/06/2023] Open
Abstract
Bacillus coagulans is a promising probiotic, because it combines probiotic properties of Lactobacillus and the ability of Bacillus to form endospores. Due to this hybrid relationship, cultivation of this organism is challenging. As the probiotics market continues to grow, there is a new focus on the production of these microorganisms. In this work, a strain-specific bioprocess for B. coagulans was developed to support growth on one hand and ensure sporulation on the other hand. This circumstance is not trivial, since these two metabolic states are contrary. The developed bioprocess uses a modified chemically defined medium which was further investigated in a one-factor-at-a-time assay after adaptation. A transfer from the shake flask to the bioreactor was successfully demonstrated in the scope of this work. The investigated process parameters included temperature, agitation and pH-control. Especially the pH-control improved the sporulation in the bioreactor when compared to shake flasks. The bioprocess resulted in a sporulation efficiency of 80%-90%. This corresponds to a sevenfold increase in sporulation efficiency due to a transfer to the bioreactor with pH-control. Additionally, a design of experiment (DoE) was conducted to test the robustness of the bioprocess. This experiment validated the beforementioned sporulation efficiency for the developed bioprocess. Afterwards the bioprocess was then scaled up from a 1 L scale to a 10 L bioreactor scale. A comparable sporulation efficiency of 80% as in the small scale was achieved. The developed bioprocess facilitates the upscaling and application to an industrial scale, and can thus help meet the increasing market for probiotics.
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Affiliation(s)
- Riekje Biermann
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
| | - Laura Rösner
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
| | - Lisa‐Marie Beyer
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
| | - Laura Niemeyer
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
| | - Sascha Beutel
- Institute of Technical ChemistryLeibniz University HannoverHannoverGermany
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4
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Moyet M, Morrill H, Espinal DL, Bernard E, Alyokhin A. Early Growth Patterns of Bacillus cereus on Potato Substrate in the Presence of Low Densities of Black Soldier Fly Larvae. Microorganisms 2023; 11:1284. [PMID: 37317258 DOI: 10.3390/microorganisms11051284] [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: 03/21/2023] [Revised: 04/26/2023] [Accepted: 05/09/2023] [Indexed: 06/16/2023] Open
Abstract
Bacillus cereus is a common and ubiquitous bacterium that can cause foodborne illnesses in humans and other animals. Common methods of contact between foodborne pathogens and their victims include exposure through contaminated food or food containment products. Using larvae of black soldier flies, Hermetia illucens, for biological conversion of wastes into components of animal feeds is a rapidly growing technology. However, contamination of larval biomass with pathogenic microorganisms may challenge its use on an industrial scale. We conducted laboratory experiments to test the effects of the black soldier fly larvae developing on simulated potato waste substrate on B. cereus abundance. We observed a general increase in the number of colony-forming units and concentration of hblD - gene when the larvae were present in the substrate, although the effect was modulated by larval densities and time since inoculation. It is possible that starch breakdown by black soldier fly larvae may provide a beneficial environment for B. cereus. Our results differ from the suppression in the presence by black soldier fly larvae reported for several other bacterial species and highlight the importance of taking proper food safety measures when using this technology.
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Affiliation(s)
- Matthew Moyet
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA
| | - Hailey Morrill
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA
| | - Daniella Leal Espinal
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA
| | - Edward Bernard
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA
| | - Andrei Alyokhin
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA
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Mohammed S, Ray L. Polyhydroxyalkanoate recovery from newly screened Bacillus sp. LPPI-18 using various methods of extraction from Loktak Lake sediment sample. J Genet Eng Biotechnol 2022; 20:115. [PMID: 35932435 PMCID: PMC9357249 DOI: 10.1186/s43141-022-00392-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 07/04/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Nowadays, the conventional plastic wastes are very challenging to environments and its production cost also creates an economic crisis due to petrochemical-based plastic. In order to solve this problem, the current studies were aimed at screening and characterizing these polyhydroxyalkanoate (PHA)-producing isolates and evaluating the suitability of some carbon source for newly screened PHA-producing isolates. MATERIAL AND METHODS Some carbon sources such as D-fructose, glucose, molasses, D-ribose and sucrose were evaluated for PHA production. Data were analyzed using SPSS version 20. The 16SrRNA gene sequence of these isolates was performed. These newly isolated taxa were related to Bacillus species. It was designated as Bacillus sp. LPPI-18 and affiliated Bacillus cereus ATCC 14577T (AE01687) (99.10%). Paenibacillus sp. 172 (AF273740.1) was used as an outgroup. RESULTS Bacillus sp. LPPI-18 is a gram-positive, rod-shaped, endospore former, and citrate test positive. This isolate showed positive for amylase, catalase, pectinase, and protease test. They produced intracellular PHA granules when this isolate was stained with Sudan Black B (SBB) and Nile blue A (NBA) preliminary and specific staining dyes, respectively. Both temperature and pH used to affect polyhydroxyalkanoates (PHA) productivity. Bacteria are able to reserve PHA in the form of granules during stress conditions. This isolate produces only when supplied with carbon sources. More PHA contents (PCs) were obtained from glucose, molasses, and D-fructose. In this regard, the maximum mean value of PC was obtained from glucose (40.55±0.7%) and the minimum was obtained from D-ribose (12.4±1.4%). Great variations (P≤0.05) of PCs were observed among glucose and sucrose, molasses and sucrose, and D-fructose and sucrose carbon sources for PHA productivity (PP) of cell dry weight (CDW) g/L. After extraction, PHA film was produced for this typical isolate using glucose as a sole carbon source. Fourier transform infrared spectrum was performed for this isolate and showed the feature of polyester at 1719.64 to 1721.16 wavelengths for these extracted samples. The peak of fingerprinting (band of carboxylic acid group) at this wavelength is a characteristic feature of polyhydroxybutyrate (PHB) and corresponds to the ester functional group (C=O). CONCLUSION In this study, newly identified Bacillus sp. LPPI-18 is found to be producing biodegradable polymers that are used to replace highly pollutant conventional plastic polymers. This isolate is also used to employ certain cost-effective carbon sources for the production of PHA polymers.
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Affiliation(s)
- Seid Mohammed
- Department of Applied Biology, SoANS, Adama Science and Technology University, Oromia, Ethiopia. .,School of Law, KIIT University, Bhubaneswar, Odisha, 751024, India.
| | - Lopamudra Ray
- School of Law, KIIT University, Bhubaneswar, Odisha, 751024, India.,School of Biotechnology, KIIT University, Bhubaneswar, Odisha, 751024, India
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Cayemitte P, Gerliani N, Raymond P, Aider M. Study of the Antibacterial Potency of Electroactivated Solutions of Calcium Lactate and Calcium Ascorbate on Bacillus cereus ATCC 14579 Vegetative Cells. ACS OMEGA 2022; 7:3579-3595. [PMID: 35128265 PMCID: PMC8811942 DOI: 10.1021/acsomega.1c06124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Bacillus cereus is a pathogenic bacterium, Gram-positive, aerobic, and facultative anaerobic that can produce spores and different toxins. It is involved in serious foodborne illnesses such as the diarrheal and emetic syndromes, depending on the ingested toxin. This work is aimed to study the potency of electroactivated solutions (EAS) of calcium lactate, calcium ascorbate, and their mixture as antibacterial agents against B. cereus ATCC 14579 vegetative cells. The solutions used were electroactivated under electric current intensities of 250, 500, and 750 mA for 30 min. The obtained EAS were tested in direct contact with B. cereus (107 CFU/mL) for different durations ranging from 5 s to 2 min. Moreover, standard lactic and ascorbic acids were tested as controls at equivalent titratable acidity as that of the corresponding electroactivated solutions. The obtained results showed that EAS exhibit high antibacterial efficacy against B. cereus vegetative cells. The EAS obtained after electroactivation of calcium lactate and calcium ascorbate were more efficient than those of their corresponding standard acids (lactic and ascorbic). The observed antibacterial effect of the EAS resulted in a reduction of 7 log CFU/mL after 5 s of direct contact in some specific cases. Scanning (SEM) and transmission (TEM) electron microscopic observations provided conclusive evidence of the antibacterial activity of the used EAS. These results outlined the highly antimicrobial potency of EAS against B. cereus vegetative cells and that they can be considered in an eventual strategy to ensure food safety, surface cleaning, as well as replacement of hazardous disinfecting chemicals.
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Affiliation(s)
- Pierre
Emerson Cayemitte
- Department
of Food Sciences, Université Laval, Quebec, Quebec G1V0A6, Canada
- Institute
of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec G1V0A6, Canada
| | - Natela Gerliani
- Institute
of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec G1V0A6, Canada
- Department
of Soil Sciences and Agri-Food Engineering, Université Laval, Quebec, Quebec G1V0A6, Canada
| | - Philippe Raymond
- Saint-Hyacinthe
Laboratory, Canadian Food Inspection Agency, 3400 Casavant Boulevard West, Saint-Hyacinthe, Quebec J2S 8E3, Canada
| | - Mohammed Aider
- Institute
of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec G1V0A6, Canada
- Department
of Soil Sciences and Agri-Food Engineering, Université Laval, Quebec, Quebec G1V0A6, Canada
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7
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Sinnelä MT, Pawluk AM, Jin YH, Kim D, Mah JH. Effect of Calcium and Manganese Supplementation on Heat Resistance of Spores of Bacillus Species Associated With Food Poisoning, Spoilage, and Fermentation. Front Microbiol 2021; 12:744953. [PMID: 34707595 PMCID: PMC8542979 DOI: 10.3389/fmicb.2021.744953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
Bacterial spores often survive thermal processing used in the food industry, while heat treatment leads not only to a decrease in the nutritional and organoleptic properties of foods, but also to a delay in fermentation of fermented foods. Selective reduction of undesirable spores without such impediments is an ongoing challenge for food scientists. Thus, increased knowledge of the spore-forming bacteria is required to control them. In this study, the heat resistance results (D100°C) of the spores of four Bacillus species were determined and compared to previous literature, and found that B. cereus has significantly lower heat resistance than the other Bacillus species, B. coagulans, B. subtilis, and B. licheniformis. Using the spores of these strains, this study also evaluated the effects of single and combined supplementation of calcium (0.00–2.00 mM) and manganese (0.00–0.50 mM) on heat resistance (D100°C). The results revealed that the spores of B. licheniformis and B. cereus displayed the smallest heat resistance when sporulated on media rich in calcium. Conversely, B. coagulans spores and B. subtilis spores exhibited the greatest heat resistance when sporulated under calcium-rich conditions. The opposite results (stronger heat resistance for B. licheniformis spores and B. cereus spores, and smaller heat resistance for B. coagulans spores and B. subtilis spores) were obtained when the spores were formed on media poor in the minerals (particularly calcium). Based on the results, the Bacillus species were divided into two groups: B. licheniformis and B. cereus; and B. coagulans and B. subtilis. The study provides valuable insight to selectively reduce spores of undesirable Bacillus species in the food industry.
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Affiliation(s)
| | | | - Young Hun Jin
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Dabin Kim
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
| | - Jae-Hyung Mah
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
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8
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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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9
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Liu S, Brul S, Zaat SAJ. Bacterial Persister-Cells and Spores in the Food Chain: Their Potential Inactivation by Antimicrobial Peptides (AMPs). Int J Mol Sci 2020; 21:E8967. [PMID: 33260797 PMCID: PMC7731242 DOI: 10.3390/ijms21238967] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022] Open
Abstract
The occurrence of bacterial pathogens in the food chain has caused a severe impact on public health and welfare in both developing and developed countries. Moreover, the existence of antimicrobial-tolerant persisting morphotypes of these pathogens including both persister-cells as well as bacterial spores contributes to difficulty in elimination and in recurrent infection. Therefore, comprehensive understanding of the behavior of these persisting bacterial forms in their environmental niche and upon infection of humans is necessary. Since traditional antimicrobials fail to kill persisters and spores due to their (extremely) low metabolic activities, antimicrobial peptides (AMPs) have been intensively investigated as one of the most promising strategies against these persisting bacterial forms, showing high efficacy of inactivation. In addition, AMP-based foodborne pathogen detection and prevention of infection has made significant progress. This review focuses on recent research on common bacterial pathogens in the food chain, their persisting morphotypes, and on AMP-based solutions. Challenges in research and application of AMPs are described.
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Affiliation(s)
- Shiqi Liu
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Stanley Brul
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
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10
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Christensen BE, Strand SP, Basset C, Kristiansen KA, Ulset AST, Ballance S, Granum PE. Macromolecular acidic coating increases shelf life by inhibition of bacterial growth. Int J Food Microbiol 2018; 285:136-143. [PMID: 30121468 DOI: 10.1016/j.ijfoodmicro.2018.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 06/18/2018] [Accepted: 08/02/2018] [Indexed: 11/17/2022]
Abstract
The sensitivity of microorganisms to low pH can be utilized in food protection by preparing coatings based on macromolecular acids. Due to limited diffusivity of macromolecules low pH occurs primarily at the surface, while the interior parts of the food remain unaffected. This principle is demonstrated using food approved alginic acid in various types of coatings (aqueous, emulsions, dispersions, dry coating) on a wide range of foods including meat, fish, chicken, shrimp and boiled rice. Significant delay or inhibition of the natural flora is generally demonstrated, particularly when exposed to 'temperature abuse'. Specifically, we show that the coatings reduce or inhibit regrowth of pathogens (Bacillus cereus, B. weihenstephanensis, Listeria monocytogenes serotype 1 and Staphylococcus aureus). In special cases like boiled rice, alginic acid may largely replace acetic acid for acidification and preservation, as demonstrated studying regrowth of added spores of B. cereus. Most formulations allow easy removal prior to further processing (cooking, frying). Temporary side effects such as 'acid cooking' obtained for high acid concentrations on sensitive surfaces (e.g. salmon) disappear during processing, recovering the normal taste and texture. The coating is hence suitable for a large variety of foods.
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Affiliation(s)
- Bjørn E Christensen
- NOBIPOL, Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
| | - Sabina P Strand
- NOBIPOL, Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Coraline Basset
- Department of Food Safety and Infection Biology, NMBU - Norwegian University of Life Sciences, N-0033 Oslo, Norway; Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403 Oslo, Norway
| | - Kåre A Kristiansen
- NOBIPOL, Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Ann-Sissel T Ulset
- NOBIPOL, Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Simon Ballance
- NOBIPOL, Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Per Einar Granum
- Department of Food Safety and Infection Biology, NMBU - Norwegian University of Life Sciences, N-0033 Oslo, Norway
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11
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Omardien S, Ter Beek A, Vischer N, Montijn R, Schuren F, Brul S. Evaluating novel synthetic compounds active against Bacillus subtilis and Bacillus cereus spores using Live imaging with SporeTrackerX. Sci Rep 2018; 8:9128. [PMID: 29904100 PMCID: PMC6002552 DOI: 10.1038/s41598-018-27529-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 06/05/2018] [Indexed: 11/12/2022] Open
Abstract
An empirical approach was taken to screen a novel synthetic compound library designed to be active against Gram-positive bacteria. We obtained five compounds that were active against spores from the model organism Bacillus subtilis and the food-borne pathogen Bacillus cereus during our population based experiments. Using single cell live imaging we were able to observe effects of the compounds on spore germination and outgrowth. Difference in sensitivity to the compounds could be observed between B. subtilis and B. cereus using live imaging, with minor difference in the minimal inhibitory and bactericidal concentrations of the compounds against the spores. The compounds all delayed the bursting time of germinated spores and affected the generation time of vegetative cells at sub-inhibitory concentrations. At inhibitory concentrations spore outgrowth was prevented. One compound showed an unexpected potential for preventing spore germination at inhibitory concentrations, which merits further investigation. Our study shows the valuable role single cell live imaging can play in the final selection process of antimicrobial compounds.
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Affiliation(s)
- Soraya Omardien
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Alexander Ter Beek
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Norbert Vischer
- Swammerdam Institute for Life Sciences, Department of Bacterial Cell Biology and Physiology, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Roy Montijn
- Microbiology and Systems Biology Group, TNO, Utrechtseweg 48, 3704HE, Zeist, The Netherlands
| | - Frank Schuren
- Microbiology and Systems Biology Group, TNO, Utrechtseweg 48, 3704HE, Zeist, The Netherlands
| | - Stanley Brul
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
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12
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Rao L, Feeherry FE, Ghosh S, Liao X, Lin X, Zhang P, Li Y, Doona CJ, Setlow P. Effects of lowering water activity by various humectants on germination of spores of Bacillus species with different germinants. Food Microbiol 2018; 72:112-127. [DOI: 10.1016/j.fm.2017.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 10/18/2022]
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13
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Stelder SK, Benito de Moya C, Hoefsloot HCJ, de Koning LJ, Brul S, de Koster CG. Stoichiometry, Absolute Abundance, and Localization of Proteins in the Bacillus cereus Spore Coat Insoluble Fraction Determined Using a QconCAT Approach. J Proteome Res 2018; 17:903-917. [PMID: 29260567 PMCID: PMC5799878 DOI: 10.1021/acs.jproteome.7b00732] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Spores of Bacillus cereus pose a threat to food
safety due to their high resistance to the heat or acid treatments
commonly used to make food microbiologically safe. Spores may survive
these treatments and later resume growth either on foodstuffs or,
after ingestion, upon entering the gut they are capable of producing
toxins, which cause either vomiting or diarrhea. The outer layers
of the spore, the spore coat and exosporium, consist primarily of
proteins that may serve as potential biomarkers for detection. The
major morphogenetic protein CotE is important for correct assembly
and attachment of the outermost layer, the exosporium, and by extension
retention of many proteins. However, characterization of the proteins
affected by deletion of CotE has been limited to electrophoretic patterns.
Here we report the effect of CotE deletion on the insoluble fraction
of the spore proteome through liquid chromatography–Fourier
transform tandem mass spectrometry (LC–FTMS/MS) analysis. A total of 560 proteins have been identified in both mutant
and wild-type spore coat isolates. A further 163 proteins were identified
exclusively in wild-type spore isolates indicating that they are dependent
on CotE for their association with the spore. Several of these are
newly confirmed as associated with the exosporium, namely BC_2569
(BclF), BC_3345, BC_2427, BC_2878, BC_0666, BC_2984, BC_3481, and
BC_2570. A total of 153 proteins were only identified in ΔCotE
spore isolates. This was observed for proteins that are known or likely
to be interacting with or are encased by CotE. Crucial spore proteins
were quantified using a QconCAT reference standard, the first time
this was used in a biochemically heterogeneous system. This allowed
us to determine the absolute abundance of 21 proteins, which spanned
across three orders of magnitude and together covered 5.66% ±
0.51 of the total spore weight. Applying the QconCAT methodology to
the ΔCotE mutant allowed us to quantify 4.13% ± 0.14 of
the spore total weight and revealed a reduction in abundance for most
known exosporium associated proteins upon CotE deletion. In contrast,
several proteins, either known or likely to be interacting with or
encased by CotE (i.e., GerQ), were more abundant. The results obtained
provide deeper insight into the layered spore structure such as which
proteins are exposed on the outside of the spore. This information
is important for developing detection methods for targeting spores
in a food safety setting. Furthermore, protein stoichiometry and determination
of the abundance of germination mediating enzymes provides useful
information for germination and outgrowth model development.
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Affiliation(s)
- Sacha K Stelder
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Celia Benito de Moya
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Huub C J Hoefsloot
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Leo J de Koning
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Stanley Brul
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Chris G de Koster
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, and §Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The Netherlands
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14
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Ikeda A, Kim D, Hashidoko Y. Identification of diacetonamine from soybean curd residue as a sporulation-inducing factor toward Bacillus spp. AMB Express 2017; 7:101. [PMID: 28545259 PMCID: PMC5442031 DOI: 10.1186/s13568-017-0395-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 04/26/2017] [Indexed: 11/15/2022] Open
Abstract
Under bioassay-guided investigation, a sporulation-inducing factor (SIF) toward Bacillus spp. was searched for in methanol (MeOH) extracts of soybean curd residues, and diacetonamine (1) was identified as the active compound. SIF was first isolated as a monoacetylated derivative (2, 4.1 mg from 655 g soybean curd residues), and its chemical structure was elucidated by field desorption mass spectrometry, electron ionization mass spectrometry, and nuclear magnetic resonance (NMR) analyses. After 48-h incubation, 40 µM diacetonamine hydrochloride (1b) exhibited sporulation-inducing activity with 35% sporulation frequency toward a Bacillus amyloliquefaciens wild-type strain (AHU 2170), whereas 40 µM diacetone acrylamide (3) showed 99% sporulation induction, which was much higher than that of 1b. Although Bacillus megaterium NBRC 15308 was sporulated by the treatment with 400 µM 1b with 36 and 70% sporulation frequency after 72- and 96-h incubation respectively, 3 at the same concentration showed only 2% sporulation after 72-h incubation. Hence, diacetonamine (1) was characterized as a genuine SIF from soybean curd residues, but it was uncertain whether 1 is a natural product or an artifact. Spores of B. amyloliquefaciens induced by 1b survived after treatment with heating at 95 °C for 10 min, also suggesting that 1 is genuine SIF in soybean curd residue. As sporulation induction is likely linked to activation of antibiotic production in some spore-forming Firmicutes bacteria, compound 1 would be a possible chemical tool to develop an effective fermentation technology in Bacillus species.
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15
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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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16
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Eijlander RT, Holsappel S, de Jong A, Ghosh A, Christie G, Kuipers OP. SpoVT: From Fine-Tuning Regulator in Bacillus subtilis to Essential Sporulation Protein in Bacillus cereus. Front Microbiol 2016; 7:1607. [PMID: 27790204 PMCID: PMC5061766 DOI: 10.3389/fmicb.2016.01607] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/26/2016] [Indexed: 12/14/2022] Open
Abstract
Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus, whereas this is not observed in Bacillus subtilis. Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus ΔspoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes.
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Affiliation(s)
- Robyn T Eijlander
- Top Institute Food and NutritionWageningen, Netherlands; Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Siger Holsappel
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Anne de Jong
- Top Institute Food and NutritionWageningen, Netherlands; Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Abhinaba Ghosh
- Department of Chemical Engineering and Biotechnology, Institute of Biotechnology, University of Cambridge Cambridge, UK
| | - Graham Christie
- Department of Chemical Engineering and Biotechnology, Institute of Biotechnology, University of Cambridge Cambridge, UK
| | - Oscar P Kuipers
- Top Institute Food and NutritionWageningen, Netherlands; Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
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17
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Soni A, Oey I, Silcock P, Bremer P. Bacillus
Spores in the Food Industry: A Review on Resistance and Response to Novel Inactivation Technologies. Compr Rev Food Sci Food Saf 2016; 15:1139-1148. [DOI: 10.1111/1541-4337.12231] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/22/2016] [Accepted: 08/29/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Aswathi Soni
- Dept. of Food Science; Univ. of Otago; PO Box 56 Dunedin 9054 New Zealand
| | - Indrawati Oey
- Dept. of Food Science; Univ. of Otago; PO Box 56 Dunedin 9054 New Zealand
| | - Pat Silcock
- Dept. of Food Science; Univ. of Otago; PO Box 56 Dunedin 9054 New Zealand
| | - Phil Bremer
- Dept. of Food Science; Univ. of Otago; PO Box 56 Dunedin 9054 New Zealand
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18
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Warda AK, Siezen RJ, Boekhorst J, Wells-Bennik MHJ, de Jong A, Kuipers OP, Nierop Groot MN, Abee T. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity. PLoS One 2016; 11:e0156796. [PMID: 27272929 PMCID: PMC4896439 DOI: 10.1371/journal.pone.0156796] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/19/2016] [Indexed: 11/19/2022] Open
Abstract
We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed.
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Affiliation(s)
- Alicja K. Warda
- TI Food and Nutrition, Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, Wageningen, The Netherlands
- Wageningen UR Food & Biobased Research, Wageningen, The Netherlands
| | - Roland J. Siezen
- TI Food and Nutrition, Wageningen, The Netherlands
- Center for Molecular and Biomolecular Informatics, RadboudUMC, Nijmegen, The Netherlands
- Microbial Bioinformatics, Ede, The Netherlands
| | - Jos Boekhorst
- TI Food and Nutrition, Wageningen, The Netherlands
- Center for Molecular and Biomolecular Informatics, RadboudUMC, Nijmegen, The Netherlands
- NIZO Food Research B.V., Ede, The Netherlands
| | | | - Anne de Jong
- TI Food and Nutrition, Wageningen, The Netherlands
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Oscar P. Kuipers
- TI Food and Nutrition, Wageningen, The Netherlands
- Department of Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Masja N. Nierop Groot
- TI Food and Nutrition, Wageningen, The Netherlands
- Wageningen UR Food & Biobased Research, Wageningen, The Netherlands
| | - Tjakko Abee
- TI Food and Nutrition, Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, Wageningen, The Netherlands
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19
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Hayrapetyan H, Abee T, Nierop Groot M. Sporulation dynamics and spore heat resistance in wet and dry biofilms of Bacillus cereus. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.08.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Sporulation Temperature Reveals a Requirement for CotE in the Assembly of both the Coat and Exosporium Layers of Bacillus cereus Spores. Appl Environ Microbiol 2015; 82:232-43. [PMID: 26497467 DOI: 10.1128/aem.02626-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/15/2015] [Indexed: 11/20/2022] Open
Abstract
The Bacillus cereus spore surface layers consist of a coat surrounded by an exosporium. We investigated the interplay between the sporulation temperature and the CotE morphogenetic protein in the assembly of the surface layers of B. cereus ATCC 14579 spores and on the resulting spore properties. The cotE deletion affects the coat and exosporium composition of the spores formed both at the suboptimal temperature of 20°C and at the optimal growth temperature of 37°C. Transmission electron microscopy revealed that ΔcotE spores had a fragmented and detached exosporium when formed at 37°C. However, when produced at 20°C, ΔcotE spores showed defects in both coat and exosporium attachment and were susceptible to lysozyme and mutanolysin. Thus, CotE has a role in the assembly of both the coat and exosporium, which is more important during sporulation at 20°C. CotE was more represented in extracts from spores formed at 20°C than at 37°C, suggesting that increased synthesis of the protein is required to maintain proper assembly of spore surface layers at the former temperature. ΔcotE spores formed at either sporulation temperature were impaired in inosine-triggered germination and resistance to UV-C and H2O2 and were less hydrophobic than wild-type (WT) spores but had a higher resistance to wet heat. While underscoring the role of CotE in the assembly of B. cereus spore surface layers, our study also suggests a contribution of the protein to functional properties of additional spore structures. Moreover, it also suggests a complex relationship between the function of a spore morphogenetic protein and environmental factors such as the temperature during spore formation.
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21
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Dettman JR, Goss JM, Ehrhardt CJ, Scott KA, Bannan JD, Robertson JM. Forensic differentiation of Bacillus cereus spores grown using different culture media using Raman spectroscopy. Anal Bioanal Chem 2015; 407:4757-66. [DOI: 10.1007/s00216-015-8677-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/02/2015] [Indexed: 11/24/2022]
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22
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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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23
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Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores. Food Microbiol 2014; 45:26-33. [PMID: 25481059 DOI: 10.1016/j.fm.2014.03.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 11/21/2022]
Abstract
Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity.
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24
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Comparative proteomic analysis of experimental evolution of the Bacillus cereus-Ketogulonicigenium vulgare co-culture. PLoS One 2014; 9:e91789. [PMID: 24619085 PMCID: PMC3950281 DOI: 10.1371/journal.pone.0091789] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 02/14/2014] [Indexed: 11/19/2022] Open
Abstract
The microbial co-culture system composing of Ketogulonicigenium vulgare and Bacillus cereus was widely adopted in industry for the production of 2-keto-gulonic acid (2-KGA), the precursor of vitamin C. We found serial subcultivation of the co-culture could enhance the yield of 2-KGA by 16% in comparison to that of the ancestral co-culture. To elucidate the evolutionary dynamics and interaction mechanisms of the two microbes, we performed iTRAQ-based quantitative proteomic analyses of the pure cultures of K. vulgare, B. cereus and their co-culture during serial subcultivation. Hierarchy cluster analyses of the proteomic data showed that the expression level of a number of crucial proteins associated with sorbose conversion and oligopeptide transport was significantly enhanced by the experimental evolution. In particular, the expression level of sorbose/sorbosone dehydrogenase was enhanced in the evolved K. vulgare, while the expression level of InhA and the transport efficiency of oligopeptides were increased in the evolved B. cereus. The decreased sporulating protein expression and increased peptide transporter expression observed in evolved B. cereus, together with the increased amino acids synthesis in evolved K. vulgare suggested that serial subcultivation result in enhanced synergistic cooperation between K. vulgare and B. cereus, enabling an increased production of 2-KGA.
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25
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Han KI, Patnaik BB, Kim YH, Kwon HJ, Han YS, Han MD. Isolation and Characterization of Chitinase-ProducingBacillusandPaenibacillusStrains from Salted and Fermented Shrimp,Acetes japonicus. J Food Sci 2014; 79:M665-74. [DOI: 10.1111/1750-3841.12387] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/07/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Kook-Il Han
- Dept. of Biology; Soonchunhyang Univ; Asan Chungnam 336-745 Republic of Korea
| | - Bharat Bhusan Patnaik
- Div. of Plant Biotechnology; College of Agriculture and Life Science; Chonnam Natl. Univ; Gwangju 500-757 Republic of Korea
| | - Yong Hyun Kim
- Dept. of Biology; Soonchunhyang Univ; Asan Chungnam 336-745 Republic of Korea
| | - Hyun-Jung Kwon
- Dept. of Biology; Soonchunhyang Univ; Asan Chungnam 336-745 Republic of Korea
| | - Yeon Soo Han
- Div. of Plant Biotechnology; College of Agriculture and Life Science; Chonnam Natl. Univ; Gwangju 500-757 Republic of Korea
| | - Man-Deuk Han
- Dept. of Biology; Soonchunhyang Univ; Asan Chungnam 336-745 Republic of Korea
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26
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van Melis CCJ, den Besten HMW, Nierop Groot MN, Abee T. Quantification of the impact of single and multiple mild stresses on outgrowth heterogeneity of Bacillus cereus spores. Int J Food Microbiol 2014; 177:57-62. [PMID: 24607860 DOI: 10.1016/j.ijfoodmicro.2014.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/13/2014] [Accepted: 02/17/2014] [Indexed: 11/19/2022]
Abstract
Outgrowth heterogeneity of bacterial spore populations complicates both prediction and efficient control of spore outgrowth. In this study, the impact of mild preservation stresses on outgrowth of Bacillus cereus ATCC 14579 spores was quantified during the first stages of outgrowth. Heterogeneity in outgrowth of heat-treated (90°C for 10 min) and non-heat-treated germinated single spores to the maximum micro-colony stage of 256 cells was assessed by direct imaging on Anopore strips, placed on BHI plates at pH7 and pH5.5, without and with added NaCl or sorbic acid (HSA). At pH7 non-heated and heat-treated germinated spores required 6h to reach the maximum microcolony stage with limited heterogeneity, and these parameters were only slightly affected with both types of spores when incubated at pH7 with added NaCl. Notably, the most pronounced effects were observed during outgrowth of spores at pH5.5 without and with added NaCl or HSA. Non-heat-treated germinated spores showed again efficient outgrowth with limited heterogeneity reaching the maximum microcolony stage after 6h at pH5.5, which increased to 12h and 16 h with added NaCl and HSA, respectively. In contrast, heat-treated spores displayed a strong delay between initial germination and swelling and further outgrowth at pH5.5, resulting in large heterogeneity and low numbers of fastest growers reaching the maximum microcolony stage after 10, 12 and 24h, without and with added NaCl or HSA, respectively. This work shows that Anopore technology provides quantitative information on the impact of combined preservation stresses on outgrowth of single spores, showing that outgrowth of germinated heat-treated spores is significantly affected at pH5.5 with a large fraction of spores arrested in the early outgrowth stage, and with outgrowing cells showing large heterogeneity with only a small fraction committed to relatively fast outgrowth.
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Affiliation(s)
- C C J van Melis
- Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands; Food Microbiology Laboratory, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - H M W den Besten
- Food Microbiology Laboratory, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - M N Nierop Groot
- Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands; Food and Biobased Research, Wageningen University & Research Centre, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - T Abee
- Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands; Food Microbiology Laboratory, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands.
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27
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Eijlander RT, de Jong A, Krawczyk AO, Holsappel S, Kuipers OP. SporeWeb: an interactive journey through the complete sporulation cycle of Bacillus subtilis. Nucleic Acids Res 2013; 42:D685-91. [PMID: 24170806 PMCID: PMC3964945 DOI: 10.1093/nar/gkt1007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bacterial spores are a continuous problem for both food-based and health-related industries. Decades of scientific research dedicated towards understanding molecular and gene regulatory aspects of sporulation, spore germination and spore properties have resulted in a wealth of data and information. To facilitate obtaining a complete overview as well as new insights concerning this complex and tightly regulated process, we have developed a database-driven knowledge platform called SporeWeb (http://sporeweb.molgenrug.nl) that focuses on gene regulatory networks during sporulation in the Gram-positive bacterium Bacillus subtilis. Dynamic features allow the user to navigate through all stages of sporulation with review-like descriptions, schematic overviews on transcriptional regulation and detailed information on all regulators and the genes under their control. The Web site supports data acquisition on sporulation genes and their expression, regulon network interactions and direct links to other knowledge platforms or relevant literature. The information found on SporeWeb (including figures and tables) can and will be updated as new information becomes available in the literature. In this way, SporeWeb offers a novel, convenient and timely reference, an information source and a data acquisition tool that will aid in the general understanding of the dynamics of the complete sporulation cycle.
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Affiliation(s)
- Robyn T Eijlander
- Top Institute Food and Nutrition (TIFN), Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands and Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
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28
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Abhyankar W, Hossain AH, Djajasaputra A, Permpoonpattana P, Ter Beek A, Dekker HL, Cutting SM, Brul S, de Koning LJ, de Koster CG. In Pursuit of Protein Targets: Proteomic Characterization of Bacterial Spore Outer Layers. J Proteome Res 2013; 12:4507-21. [DOI: 10.1021/pr4005629] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Patima Permpoonpattana
- School
of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, United Kingdom
| | | | | | - Simon M. Cutting
- School
of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, United Kingdom
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29
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Live-cell imaging tool optimization to study gene expression levels and dynamics in single cells of Bacillus cereus. Appl Environ Microbiol 2013; 79:5643-51. [PMID: 23851094 DOI: 10.1128/aem.01347-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Single-cell methods are a powerful application in microbial research to study the molecular mechanism underlying phenotypic heterogeneity and cell-to-cell variability. Here, we describe the optimization and application of single-cell time-lapse fluorescence microscopy for the food spoilage bacterium Bacillus cereus specifically. This technique is useful to study cellular development and adaptation, gene expression, protein localization, protein mobility, and cell-to-cell communication over time at the single-cell level. By adjusting existing protocols, we have enabled the visualization of growth and development of single B. cereus cells within a microcolony over time. Additionally, several different fluorescent reporter proteins were tested in order to select the most suitable green fluorescent protein (GFP) and red fluorescent protein (RFP) candidates for visualization of growth stage- and cell compartment-specific gene expression in B. cereus. With a case study concerning cotD expression during sporulation, we demonstrate the applicability of time-lapse fluorescence microscopy. It enables the assessment of gene expression levels, dynamics, and heterogeneity at the single-cell level. We show that cotD is not heterogeneously expressed among cells of a subpopulation. Furthermore, we discourage using plasmid-based reporter fusions for such studies, due to an introduced heterogeneity through copy number differences. This stresses the importance of using single-copy integrated reporter fusions for single-cell studies.
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30
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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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Germination inhibition of Bacillus cereus spores: impact of the lipophilic character of inhibiting compounds. Int J Food Microbiol 2012. [DOI: 10.1016/j.ijfoodmicro.2012.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Impact of sorbic acid on germination and outgrowth heterogeneity of Bacillus cereus ATCC 14579 spores. Appl Environ Microbiol 2012; 78:8477-80. [PMID: 23001664 DOI: 10.1128/aem.02361-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Population heterogeneity complicates the predictability of the outgrowth kinetics of individual spores. Flow cytometry sorting and monitoring of the germination and outgrowth of single dormant spores allowed the quantification of acid-induced spore population heterogeneity at pH 5.5 and in the presence of sorbic acid. This showed that germination efficiency was not a good predictor for heterogeneity in final outgrowth.
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From C, van der Voort M, Abee T, Granum PE. Characterization of a spore-specific protein of the Bacillus cereus group. FEMS Microbiol Lett 2012; 331:152-9. [PMID: 22458449 DOI: 10.1111/j.1574-6968.2012.02562.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 03/23/2012] [Accepted: 03/26/2012] [Indexed: 11/30/2022] Open
Abstract
Bc1245 is a monocistronic chromosomal gene of Bacillus cereus ATCC 14579 encoding a putative protein of 143 amino acids identified in this study to have a spore-related function in B. cereus. Bc1245 is highly conserved in the genome of members of the B. cereus group, indicating an important function of the gene in this group of bacteria. Quantitative PCR revealed that bc1245 is transcribed late in sporulation (upon formation of phase-bright spores) and at the same time as the mother cell-specific transcription factor σ(K) . The σ(K) regulon includes structural components of the spore (such as coat proteins), and it is therefore plausible that bc1245 might encode a structural outer spore protein. This was confirmed by detection of BC1245 in exosporium extracts from B. cereus by immunoblotting against BC1245 antiserum.
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Affiliation(s)
- Cecilie From
- Department of Food Safety and Infection Biology, Section for Food Safety, Norwegian School of Veterinary Science, Oslo, Norway
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Narayanan A, Ramana KV. Polyhydroxybutyrate production in Bacillus mycoides DFC1 using response surface optimization for physico-chemical process parameters. 3 Biotech 2012. [PMCID: PMC3482451 DOI: 10.1007/s13205-012-0054-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The production of polyhydroxybutyrate (PHB) by Bacillus sp. is most often growth associated and is influenced by
various physico-chemical parameters. Imbalanced nutrient conditions were often found
to result in sporulation and low PHB production in Bacillus sp. In the present investigation, Bacillus mycoides DFC1 strain isolated from garden soil was studied
for PHB production in glucose–peptone broth. The effect of glucose/peptone ratio on
biomass yield, PHB production and sporulation was investigated. Central composite
rotatable design was used to study the interactive effects of three variables:
glucose, peptone and pH on cell growth and PHB production. The optimized medium
conditions with the constraint ‘to maximize’ cell growth and PHB content were
glucose 17.34 g/l, peptone 7.03 g/l at pH 7.3. A maximum dry cell weight of 4.35 g/l
and PHB yield of 3.32 g/l amounting to 76.32 % (w/w) of dry cell weight with
negligible sporulation at the end of 72 h resulted in a significant increase
(1.83–3.32 g/l or 1.82-fold) in the production of PHB in comparison to the medium
used in preliminary studies.
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Affiliation(s)
- Aarthi Narayanan
- Food Biotechnology Division, Defence Food Research Laboratory, Siddharthanagar, Mysore, 570011 Karnataka India
| | - Karna Venkata Ramana
- Food Biotechnology Division, Defence Food Research Laboratory, Siddharthanagar, Mysore, 570011 Karnataka India
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Fadli M, Saad A, Sayadi S, Chevalier J, Mezrioui NE, Pagès JM, Hassani L. Antibacterial activity of Thymus maroccanus and Thymus broussonetii essential oils against nosocomial infection - bacteria and their synergistic potential with antibiotics. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:464-471. [PMID: 22257599 DOI: 10.1016/j.phymed.2011.12.003] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 11/14/2011] [Accepted: 12/13/2011] [Indexed: 05/28/2023]
Abstract
The aim of this study was to evaluate the antibacterial effect of the association between conventional antibiotics and essential oils (EOs) of endemic Moroccan thyme species, Thymus maroccanus and T. broussonetii, on antibiotic-resistant bacteria involved in nosocomial infections. Synergistic interactions between antibiotics (ciprofloxacin, gentamicin, pristinamycin, and cefixime) and EOs, and between T. maroccanus and T. Broussonetii EOs were determined by the checkerboard test. Serial dilutions of two antimicrobial agents were mixed together so that each row (and column) contained a fixed amount of the first agent and increasing amounts of the second one. The results indicate that the oils had a high inhibitory activity against tested bacteria, except for Pseudomonas aeruginosa. In parallel with the increase of cellular killing, the release of 260nm-absorbing materials from bacterial cells, treated with EOs, increased in response to oil concentration. Out of 80 combinations tested between EOs and antibiotics, 71% showed total synergism, 20% had partial synergistic interaction and 9% showed no effect. Combination with carvacrol, the major constituent of T. maroccanus and T. broussonetii, showed also an interesting synergistic effect in combination with ciprofloxacin. The effect on Gram-positive bacteria was more important than on Gram-negative bacteria. These findings are very promising since the use of these combinations for nosocomial infections treatment is likely to reduce the minimum effective dose of the antibiotics, thus minimizing their possible toxic side effects and treatment cost. However, further investigations are needed to assess the potential for therapeutic application.
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Affiliation(s)
- Mariam Fadli
- Laboratoire de Biologie et Biotechnologie des Microorganismes, Pôle d'Excellence Régionale AUF, Faculté des Sciences Semlalia, Université Cadi Ayyad, B.P. 2390, 40000 Marrakech, Morocco
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36
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Boniolo FS, Rodrigues RC, Prata AMR, López ML, Jacinto T, da Silveira MM, Berbert-Molina MA. Oxygen supply in Bacillus thuringiensis fermentations: bringing new insights on their impact on sporulation and δ-endotoxin production. Appl Microbiol Biotechnol 2012; 94:625-36. [DOI: 10.1007/s00253-011-3746-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 11/02/2011] [Accepted: 11/17/2011] [Indexed: 11/28/2022]
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Gong Y, Li M, Xu D, Wang H, He J, Wu D, Chen D, Qiu N, Bao Q, Sun M, Yu Z. Comparative proteomic analysis revealed metabolic changes and the translational regulation of Cry protein synthesis in Bacillus thuringiensis. J Proteomics 2012; 75:1235-46. [DOI: 10.1016/j.jprot.2011.10.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 10/29/2011] [Accepted: 10/31/2011] [Indexed: 01/15/2023]
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Mellegård H, From C, Christensen BE, Granum PE. Inhibition of Bacillus cereus spore outgrowth and multiplication by chitosan. Int J Food Microbiol 2011; 149:218-25. [PMID: 21798612 DOI: 10.1016/j.ijfoodmicro.2011.06.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/14/2011] [Accepted: 06/18/2011] [Indexed: 11/29/2022]
Abstract
Bacillus cereus is an endospore-forming bacterium able to cause food-associated illness. Different treatment processes are used in the food industry to reduce the number of spores and thereby the potential of foodborne disease. Chitosan is a polysaccharide with well-documented antibacterial activity towards vegetative cells. The activity against bacterial spores, spore germination and subsequent outgrowth and growth (the latter two events hereafter denoted (out)growth), however, is poorly documented. By using six different chitosans with defined macromolecular properties, we evaluated the effect of chitosan on Bacillus cereus spore germination and (out)growth using optical density assays and a dipicolinic acid release assay. (Out)growth was inhibited by chitosan, but germination was not. The action of chitosan was found to be concentration-dependent and also closely related to weight average molecular weight (M(w)) and fraction of acetylation (F(A)) of the biopolymer. Chitosans of low acetylation (F(A)=0.01 or 0.16) inhibited (out)growth more effectively than higher acetylated chitosans (F(A)=0.48). For the F(A)=0.16 chitosans with medium (56.8kDa) and higher M(w) (98.3kDa), a better (out)growth inhibition was observed compared to low M(w) (10.6kDa) chitosan. The same trend was not evident with chitosans of 0.48 acetylation, where the difference in activity between the low (19.6kDa) and high M(w) (163.0kDa) chitosans was only minor. In a spore test concentration corresponding to 10(2)-10(3)CFU/ml (spore numbers relevant to food), less chitosan was needed to suppress (out)growth compared to higher spore numbers (equivalent to 10(8)CFU/ml), as expected. No major differences in chitosan susceptibility between three different strains of B. cereus were detected. Our results contribute to a better understanding of chitosan activity towards bacterial spore germination and (out)growth.
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Affiliation(s)
- Hilde Mellegård
- Dept. of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146 Dep, NO-0033 Oslo, Norway
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Fricker M, Ågren J, Segerman B, Knutsson R, Ehling-Schulz M. Evaluation of Bacillus strains as model systems for the work on Bacillus anthracis spores. Int J Food Microbiol 2010; 145 Suppl 1:S129-36. [PMID: 20800917 DOI: 10.1016/j.ijfoodmicro.2010.07.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 07/30/2010] [Accepted: 07/31/2010] [Indexed: 10/19/2022]
Abstract
Available strain collections of Bacillus anthracis and Bacillus cereus were screened for B. cereus strains sharing major genotypic characteristics with B. anthracis. Based on the comparison of partial spoIIIAB sequences, whole genome sequences and MLST, a strain set representing different lineages including candidate model strains for B. anthracis was compiled. Spores from the selected strain set and two B. anthracis strains were prepared according to a newly optimized protocol transferable to biosafety level-3 (BSL3) conditions and phenotypic characteristics including scanning electron microscopy (SEM), heat inactivation, and germination were evaluated. Two B. cereus isolates were identified that were genetically related to B. anthracis and showed high similarity to B. anthracis spores in their heat inactivation profile and their response to the germinants l-alanine and inosine. In addition, these isolates were also mimicking B. anthracis on modified PLET, a selective plating medium for B. anthracis, and shared various other biochemical characteristics with B. anthracis. Therefore these two strains are not only appropriate models for B. anthracis in experiments based on spore characteristics but also in trials working with plating media. These two strains are now used within the BIOTRACER consortium as validated models for B. anthracis and will facilitate the development and optimization of tracing and detection systems for B. anthracis in the food and feed chain.
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Affiliation(s)
- Martina Fricker
- Food Microbiology Unit, Clinic for Ruminants, Dept for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
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Spores of Bacillus cereus strain KBAB4 produced at 10 °C and 30 °C display variations in their properties. Food Microbiol 2010; 28:291-7. [PMID: 21315986 DOI: 10.1016/j.fm.2010.07.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 07/14/2010] [Accepted: 07/17/2010] [Indexed: 11/23/2022]
Abstract
Spores of the psychrotrophic Bacillus cereus KBAB4 strain were produced at 10 °C and 30 °C in fermentors. Spores produced at 30 °C were more resistant to wet heat at 85 °C, 1% glutaraldehyde, 5% hydrogen peroxide, 1M NaOH and pulsed light at fluences between 0.5 and 1.75 Jcm(-2) and to a lesser extent to monochromatic UV-C at 254 nm. No difference in resistance to 0.25 mM formaldehyde, 1M nitrous acid and 0.025 gl(-1) calcium hypochlorite was observed. Spores produced at 10 °C germinated more efficiently with 10 mM and 100 mM l-alanine than spores produced at 30 °C, while no difference in germination was observed with inosine. Dipicolinic acid (DPA) content in the spore was significantly higher for spores prepared at 30 °C. Composition of certain fatty acids varied significantly between spores produced at 10 °C and 30 °C.
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41
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van Melis CCJ, Nierop Groot MN, Tempelaars MH, Moezelaar R, Abee T. Characterization of germination and outgrowth of sorbic acid-stressed Bacillus cereus ATCC 14579 spores: phenotype and transcriptome analysis. Food Microbiol 2010; 28:275-83. [PMID: 21315984 DOI: 10.1016/j.fm.2010.04.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 04/01/2010] [Accepted: 04/10/2010] [Indexed: 11/15/2022]
Abstract
Sorbic acid (SA) is widely used as a preservative, but the effect of SA on spore germination and outgrowth has gained limited attention up to now. Therefore, the effect of sorbic acid on germination of spores of Bacillus cereus strain ATCC 14579 was analyzed both at phenotype and transcriptome level. Spore germination and outgrowth were assessed at pH 5.5 without and with 0.75, 1.5 and 3.0 mM (final concentrations) undissociated sorbic acid (HSA). This resulted in distinct HSA concentration-dependent phenotypes, varying from reduced germination and outgrowth rates to complete blockage of germination at 3.0 mM HSA. The phenotypes reflecting different stages in the germination process could be confirmed using flow cytometry and could be recognized at transcriptome level by distinct expression profiles. In the absence and presence of 0.75 and 1.5 mM HSA, similar cellular ATP levels were found up to the initial stage of outgrowth, suggesting that HSA-induced inhibition of outgrowth is not caused by depletion of ATP. Transcriptome analysis revealed the presence of a limited number of transcripts in dormant spores, outgrowth related expression, and genes specifically associated with sorbic acid stress, including alterations in cell envelope and multidrug resistance. The potential role of these HSA-stress associated genes in spore outgrowth is discussed.
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Affiliation(s)
- C C J van Melis
- Top Institute Food and Nutrition, Wageningen, The Netherlands.
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42
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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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43
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Grainger WH, Machón C, Scott DJ, Soultanas P. DnaB proteolysis in vivo regulates oligomerization and its localization at oriC in Bacillus subtilis. Nucleic Acids Res 2010; 38:2851-64. [PMID: 20071750 PMCID: PMC2874997 DOI: 10.1093/nar/gkp1236] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Initiation of bacterial DNA replication at oriC is mediated by primosomal proteins that act cooperatively to melt an AT-rich region where the replicative helicase is loaded prior to the assembly of the replication fork. In Bacillus subtilis, the dnaD, dnaB and dnaI genes are essential for initiation of DNA replication. We established that their mRNAs are maintained in fast growing asynchronous cultures. DnaB is truncated at its C-terminus in a growth phase-dependent manner. Proteolysis is confined to cytosolic, not to membrane-associated DnaB, and affects oligomerization. Truncated DnaB is depleted at the oriC relative to the native protein. We propose that DNA-induced oligomerization is essential for its action at oriC and proteolysis regulates its localization at oriC. We show that DnaB has two separate ssDNA-binding sites one located within residues 1–300 and another between residues 365–428, and a dsDNA-binding site within residues 365–428. Tetramerization of DnaB is mediated within residues 1–300, and DNA-dependent oligomerization within residues 365–428. Finally, we show that association of DnaB with the oriC is asymmetric and extensive. It encompasses an area from the middle of dnaA to the end of yaaA that includes the AT-rich region melted during the initiation stage of DNA replication.
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Affiliation(s)
- William H Grainger
- Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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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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45
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orf4 of the Bacillus cereus sigB gene cluster encodes a general stress-inducible Dps-like bacterioferritin. J Bacteriol 2009; 191:4522-33. [PMID: 19429618 DOI: 10.1128/jb.00272-09] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The function of orf4 in the sigB cluster in Bacillus cereus ATCC 14579 remains to be explored. Amino-acid sequence analysis has revealed that Orf4 is homologous with bacterioferritins and Dps. In this study, we generated an orf4-null mutant and produced recombinant protein rOrf4 to establish the role of orf4. In vitro, the purified rOrf4 was found to exist in two distinct forms, a dimeric form and a polymer form, through size exclusion analysis. The latter form exhibited a unique filament structure, in contrast to the typical spherical tetracosamer structure of bacterioferritins; the former can be induced to form rOrf4 polymers immediately after the addition of FeCl(2). Catalysis of the oxidation of ferrous irons by ferroxidase activity was detected with rOrf4, and the mineralized irons were subsequently sequestered only in the rOrf4 polymer. Moreover, rOrf4 exerted DNA-protective activity against oxidative damage via DNA binding in a nonspecific manner, as is seen with Dps. In vivo, deletion of orf4 had no effect on activation of the alternative sigma factor sigma(B), and therefore, orf4 is not associated with sigma(B) regulation; however, orf4 can be significantly upregulated upon environmental stress but not H(2)O(2) treatment. B. cereus strains with constitutive Orf4 expression exhibited a viability higher than that of the orf4-null mutant, under specific oxidative stress or heat shock. Taken together, these results suggest that Orf4 functions as a Dps-like bacterioferritin in response to environmental stress and can provide cell protection from oxidative damage through iron sequestration and DNA binding.
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Role of germinant receptors in Caco-2 cell-initiated germination of Bacillus cereus ATCC 14579 endospores. Appl Environ Microbiol 2008; 75:1201-3. [PMID: 19088316 DOI: 10.1128/aem.02238-08] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spores obtained from Bacillus cereus ATCC 14579 and mutant strains lacking each of seven germinant receptor operons were exposed to differentiated Caco-2 cells and monitored for germination. Spores of the gerI and gerL mutants showed a reduced germination response, pointing to a role for these receptors in Caco-2-induced germination.
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47
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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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48
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Jetiyanon K, Wittaya-Areekul S, Plianbangchang P. Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement. Can J Microbiol 2008; 54:861-7. [DOI: 10.1139/w08-079] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P ≤ 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.
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Affiliation(s)
- Kanchalee Jetiyanon
- Faculty of Agriculture, Natural Resources, and Environment, Naresuan University, Phitsanulok, 65000, Thailand
- Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, 65000, Thailand
| | - Sakchai Wittaya-Areekul
- Faculty of Agriculture, Natural Resources, and Environment, Naresuan University, Phitsanulok, 65000, Thailand
- Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, 65000, Thailand
| | - Pinyupa Plianbangchang
- Faculty of Agriculture, Natural Resources, and Environment, Naresuan University, Phitsanulok, 65000, Thailand
- Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, 65000, Thailand
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Badaoui Najjar M, Kashtanov D, Chikindas ML. Epsilon-poly-L-lysine and nisin A act synergistically against Gram-positive food-borne pathogens Bacillus cereus and Listeria monocytogenes. Lett Appl Microbiol 2007; 45:13-8. [PMID: 17594454 DOI: 10.1111/j.1472-765x.2007.02157.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To test epsilon-poly-L-lysine and nisin A for possible synergistic activity against selected food-borne pathogens and food spoilage organisms. METHODS AND RESULTS Synergistic activity was observed against Gram-positive Listeria monocytogenes and Bacillus cereus cells and spores of B. cereus in 96 well plate assays. However, nisin A had no effect alone or in combination with epsilon-poly-L-lysine against Gram-negative Escherichia coli cells. In addition, when tested against yeast Zygosaccharomyces bailii, nisin A and partially inhibitory concentrations of epsilon-poly-L-lysine antagonized each other. CONCLUSIONS Nisin A and epsilon-poly-L-lysine showed synergistic activity against B. cereus and L. monocytogenes. SIGNIFICANCE AND IMPACT OF THE STUDY The application of nisin A and epsilon-poly-L-lysine is a promising all-natural method of controlling Gram-positive food-borne pathogens, spores and spoilage organisms.
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Affiliation(s)
- M Badaoui Najjar
- Department of Food Science, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
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50
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Wijman JGE, de Leeuw PPLA, Moezelaar R, Zwietering MH, Abee T. Air-liquid interface biofilms of Bacillus cereus: formation, sporulation, and dispersion. Appl Environ Microbiol 2007; 73:1481-8. [PMID: 17209076 PMCID: PMC1828785 DOI: 10.1128/aem.01781-06] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Biofilm formation by Bacillus cereus was assessed using 56 strains of B. cereus, including the two sequenced strains, ATCC 14579 and ATCC 10987. Biofilm production in microtiter plates was found to be strongly dependent on incubation time, temperature, and medium, as well as the strain used, with some strains showing biofilm formation within 24 h and subsequent dispersion within the next 24 h. A selection of strains was used for quantitative analysis of biofilm formation on stainless steel coupons. Thick biofilms of B. cereus developed at the air-liquid interface, while the amount of biofilm formed was much lower in submerged systems. This suggests that B. cereus biofilms may develop particularly in industrial storage and piping systems that are partly filled during operation or where residual liquid has remained after a production cycle. Moreover, depending on the strain and culture conditions, spores constituted up to 90% of the total biofilm counts. This indicates that B. cereus biofilms can act as a nidus for spore formation and subsequently can release their spores into food production environments.
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Affiliation(s)
- Janneke G E Wijman
- Wageningen Centre for Food Sciences, Wageningen University, Laboratory of Food Microbiology, Bomenweg 2, 6703 HD Wageningen, The Netherlands
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