Recherche de bactériocines produites par les bactéries lactiques du lait

Abstract

The analysis of raw camel milk from l’Oued and M’sila and of fermented cow milk collected from Sétif led to the isolation of 76 strains of lactic acid bacteria identified on the basis of their 16S rDNA sequence as belonging to the following genera: Enterococcus, Lactobacillus, Lactococcus and Leuconostoc. Lactobacillus was the main genus isolated from cow and camel milk collected from M’sila. However, Enterococcus was the dominant genus identified in the camel milk of l’Oued. Antibacterial activity experiments showed 26 strains only exhibiting an anti-Listeria potential from which 12, isolated from camel milk, had an important inhibitor activity. However, the two methods used in this study, adsorption-desorption and precipitation with ammonium sulphate, did not show any bacteriocinogenic activity. The potential high anti-Listeria activity of these lactic acid strains and their large spectrum of antibacterial activity, including spoilage bacteria, make them good candidates in industrial food bio preservation and biotechnological transformation of milk.