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Reconstitution de communautés microbiennes complexes pour l'inhibition de Listeria monocytogenes à la surface de fromages à pâte pressée non cuite

Abstract : The objective aimed at determining if microbial diversity can be an asset to guarantee the microbial safety of raw milk cheeses against Listeria monocytogenes. The strategy was to screen microbial communities of St Nectaire's rind cheeses with anti-listerial properties, then to reconstitute communities of more simplified composition. Ten microbial consortia naturally present on the surface of raw milk cheeses out of thirty four tested can self-protect against L. monocytogenes. The most inhibitory complex consortium was constituted by 8 species of lactic bacteria, among them some are not frequent in dairy products Brochothrix thermosphacta, Marinilactibacillus psychrotolerans and Carnobacterium mobile, 12 species of Gram positive and catalase positive bacteria, 10 species of Gram negative bacteria, 4 species of yeasts and 3 molds. It was difficult to reconstitute. The results from plate counting and analysis by single strand conformation polymorphism (SSCP) converged to show that bacterial profiles from natural consortium were more diverse than the defined consortia. Nevertheless, a simplified consortium composed of bacteria growing on "Brain Heart Infusion" medium and characterized by the presence of Gram negative bacteria and the dominance of Brochothrix, Carnobacterium and Marinilactibacillus in particular at the end of ripening, was nearly as inhibitory as the complex consortium. The inhibition by this consortium was essentially associated with the production of lactic acid in the beginning of ripening and acetic acid at the end of ripening. The inhibition could be impaired by the consumption of lactate by yeasts.
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https://tel.archives-ouvertes.fr/tel-00719220
Contributor : Camille Meyer <>
Submitted on : Thursday, July 19, 2012 - 12:21:40 PM
Last modification on : Saturday, June 6, 2020 - 11:09:32 PM
Long-term archiving on: : Friday, December 16, 2016 - 1:07:22 AM

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  • HAL Id : tel-00719220, version 1
  • PRODINRA : 244826

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Emilie Retureau. Reconstitution de communautés microbiennes complexes pour l'inhibition de Listeria monocytogenes à la surface de fromages à pâte pressée non cuite. Alimentation et Nutrition. Université Blaise Pascal - Clermont-Ferrand II; Université d'Auvergne - Clermont-Ferrand I, 2010. Français. ⟨NNT : 2010CLF22035⟩. ⟨tel-00719220⟩

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