Skip to Main content Skip to Navigation
Theses

Effet de barrière des populations microbiennes des laits crus vis-à-vis de Listeria monocytogenes dans un fromage à pâte pressée non cuite

Abstract : In order to control the sanitary quality of raw milk cheeses, this thesis aimed to determine if and how the microbial populations of raw milks could act as a barrier against Listeria monocytogenes in a Saint-Nectaire cheese type technology. The comparison of SSCP profiles of chesses with and without development of L monocytogenes allowed to identify the peaks of Lactococcus lactis, Lactococcus. garvieae, Enterococcus saccharominimus, Enterococcus faecium Chryseobacterium sp. and Corynebacterium flavescens only dominant in the microbial profiles of inhibitory cheeses. Lc. lactis appeared to be the most inhibitory in cheeses at the beginning of ripening by lactic acid production. The inventory of the populations of the most inhibitory raw milk allowed to reconstitute a community of 32 species divided into 4 groups: lactic bacteria, Gram positive non lactic bacteria, Gram negative bacteria and yeasts. The application of the SSCP technique, on the DNA extracted from cheeses or from the microbial communities cultivated on various media, was insufficient to evaluate the establishment of all the microbial populations and to highlight interactions between them. However, by successive omission of the microbial groups of this community, it was shown that the group of the lactic bacteria (Lactobacillus, Leuconostoc) acted in synergy with the Gram positive non lactic bacteria in L. monocytogenes inhibition. The role of the yeasts in the inhibition would be less and the Gram negative bacteria would not intervene. During the ripening, the inhibition would be rather allotted to the production of organic acids (Dlactate, acetate), of alcohols (1-pentanol, 2-propanol, 2-butanol) and some esters (ethyl formate, ethyl acetate).
Document type :
Theses
Complete list of metadata

Cited literature [206 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00717826
Contributor : Camille Meyer <>
Submitted on : Friday, July 13, 2012 - 5:02:47 PM
Last modification on : Tuesday, April 20, 2021 - 11:54:02 AM
Long-term archiving on: : Sunday, October 14, 2012 - 3:21:15 AM

Identifiers

  • HAL Id : tel-00717826, version 1

Collections

Citation

Marjorie Saubusse. Effet de barrière des populations microbiennes des laits crus vis-à-vis de Listeria monocytogenes dans un fromage à pâte pressée non cuite. Biochimie, Biologie Moléculaire. Université Blaise Pascal - Clermont-Ferrand II; Université d'Auvergne - Clermont-Ferrand I, 2007. Français. ⟨NNT : 2007CLF21741⟩. ⟨tel-00717826⟩

Share

Metrics

Record views

839

Files downloads

3761