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Ecosystème microbien d'un atelier fermier de salaison : Identification et propriétés des bactéries lactiques

Abstract : Traditional productions represent an important socio-economic deal. However, hygiene management in small scale-facilities is still variable and can lead to a product loss, which can reach 25% at certain periods of the year.

Our study carried out within the framework of 2 research programs, regional and European, aimed to study the microbial ecosystem of a small-scale facility producing traditional dry sausages without using starter cultures and to propose solutions to improve hygienic and technological qualities of dry sausage, without change of its typicality

The quantitative and qualitative description of this facility microbial ecosystem showed a weak control of hygiene, a use of non appropriate cleaning and disinfection programs, as well as a low acidity of the product (pH 6.2 – 6.5). Considering the isolates collection made up during this first stage, we identified and characterized lactic acid bacteria (LAB) in order to develop a starter culture and a “barrier flora” from the facility endogenous flora.

The identification of 88 LAB isolates by phenotypic, genotypic and spectroscopic methods showed that Enterococcus faecium (25%) and Vagococcus carniphilus (12.5%) dominate the facility surfaces and equipment, whereas Lactococcus garvieae (18.2%) and Lactobacillus sakei (40.9%) dominate the batter and the sausage respectively.

The 36 Lb. sakei strains were characterized in respect to their potential use as starter cultures. A multivariate analysis performed on data recorded on strains allowed selecting 2 strains that can be considered in the development of a specific starter culture for this small-scale facility. Moreover, 5 Vc. carniphilus, 3 Ec. faecium, 1 Lb. sakei and 1 Enterococcus sp. were tested for displaying antibacterial activity against Listeria innocua, Staphylococcus aureus and/or Hafnia alvei in dual species biofilms. Two Ec. faecium strains were characterized as being able to constitute a “barrier flora” on the facility surfaces and equipments.

Otherwise, in order to set up appropriate decontamination procedures to this small-scale facility, several decontamination solutions were tested for their selective bactericidal effect on technological, spoilage and pathogenic bacteria isolated from this facility and cultivated in biofilms. The disinfecting chemical used in this workshop proved to be nonselective, destroying the technological flora. In contrary, the solution made of acetic acid pH 5.4 and monolaurin (0.075% w/v) was selective, inhibiting undesirable bacteria with levels being able to reach 4 log10 c.f.u/ml, whereas the technological flora was slightly affected.

These results suggest the possibility of improving the quality of traditional dry sausage by setting up a directed microbial ecology approach in small scale-facilities.
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https://tel.archives-ouvertes.fr/tel-00104633
Contributor : Mohammed Salim Ammor <>
Submitted on : Sunday, October 8, 2006 - 6:05:08 PM
Last modification on : Sunday, October 8, 2006 - 8:53:37 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 6:54:55 PM

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  • HAL Id : tel-00104633, version 1

Citation

Mohammed Salim Ammor. Ecosystème microbien d'un atelier fermier de salaison : Identification et propriétés des bactéries lactiques. Biologie cellulaire. Agrocampus - Ecole nationale supérieure d'agronomie de rennes, 2004. Français. ⟨tel-00104633⟩

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