PhD thesis of Antoine Gaillac (2020-2024)

Brochothrix thermosphacta is one of the resident bacterial communities of smoked salmon processing plants (Maillet et al. 2021). It has also been identified in the air and on the surfaces of meat processing plants. There is a great genetic diversity within this species that cannot be correlated with its ecological origin (Illikoud et al. 2019). The thesis project will therefore aim to determine whether the resident character of B. thermosphacta on surfaces of food factories can be explained by its ability to produce biofilms and to resist agents used for cleaning and disinfection. This will involve evaluating the ability of several strains of B. thermosphacta to form biofilms under more or less stressful conditions (cold and chemical stress) and to study the architecture of these biofilms.
The thesis belongs to the BROFILM project and is co-financed by INRAE ​​and the Pays de la Loire region and carried out in partnership with the "Biofilms and Spatially Organized Communities" team of the Micalis-INRAE ​​Institute.

References :

• Illikoud, N., A. Rossero, R. Chauvet, P. Courcoux, M.-F. Pilet, T. Charrier, E. Jaffrès and M. Zagorec 2019. Genotypic and phenotypic characterization of the food spoilage bacterium Brochothrix thermosphacta. Food Microbiology 81: 22-31. https://doi.org/10.1016/j.fm.2018.01.015. Ranking du JCR: Q1. Facteur d'impact à 2 ans: 4.155, Notoriété: excellente.
• Maillet, A., A. Bouju-Albert, S. Roblin, P. Vaissié, S. Leuillet, X. Dousset, E. Jaffrès, J. Combrisson and H. Prévost 2021. Impact of DNA extraction and sampling methods on bacterial communities monitored by 16S rDNA metabarcoding in cold-smoked salmon and processing plant surfaces. Food Microbiology 95. https://doi.org/10.1016/j.fm.2020.103705.

Valorisation :

• Gaillac, A., C. Gourin, L. Dubreil, R. Briandet, H. Prévost and E. Jaffrès 2024. Biofilm formation of the food spoiler Brochothrix thermosphacta on different industrial surface materials using a biofilm reactor. Food Microbiology 120: 104457. https://doi.org/10.1016/j.fm.2023.104457
• Gaillac, A., R. Briandet, E. Delahaye, J. Deschamps, E. Vigneau, P. Courcoux, E. Jaffres and H. Prevost 2022. Exploring the diversity of biofilm formation by the food spoiler Brochothrix thermosphacta. Microorganisms 10(12). https://doi.org/10.3390/microorganisms10122474