Biocontrol of Bacillus cereus by bacteriophages for improving food safety
(2019)
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- Authors
- Supervisors
- Mahillon, Jacques
- Abstract
- Nowadays, the new trend in food consumption is on organic and local products with less chemical sanitisers. In order to respond to this consumer demand, the biopreservation approaches have received an increasing attention along the food chain. Among the potential biopreservatives, bacteriophages, i.e. viruses infecting bacteria, appeared to be a promising natural, green and targeted antibacterial tool. Among the foodborne pathogens which are frequently present in food industries, B. cereus, and its psychrotrophic ecotype B. weihenstephanensis, are implicated each year in a growing number of foodborne intoxication cases with, unfortunately, some fatal issues. This study aimed to get more insights on the phage biocontrol potential against B. cereus implicated in the emetic syndrome of food intoxication. The first step was the isolation of environmental phages infecting emetic B. cereus. Then, phages showing lytic activity on the largest panel of emetic strains were characterised according their host range and stability. Five phages considered as the most promising candidates were sequenced and observed by electronic microscopy with the aim to ensure their virulent nature. In a second part, the biocontrol efficiency of the best candidate, called Deep-Blue, was evaluated either in lab-media or real food matrices (milk, rice) against several emetic B. weihenstephanensis. Depending on the food matrices and storage conditions, Deep-Blue was able to slow down the bacterial growth or to decrease the bacterial count under the initial contamination level. Deep-Blue was therefore considered as a promising phage against emetic B. weihenstephanensis and should be applied as part of a phage cocktail such as a biosanitiser against biofilm or as a biopreservative in food.
- Affiliations
Citations
Hock, L. (2019). Biocontrol of Bacillus cereus by bacteriophages for improving food safety. https://hdl.handle.net/2078.5/53779