Isolement et identification des bactéries Lactiques autochtones isolées de lait de Vache de la région de Relizane

Abstract

Lactic acid bacteria play a major role in the production of fermented food products. They contribute to improving the taste, appearance and microbiological harmlessness of the food. The aim of this study was to evaluate the diversity of lactobacilli which belong to the useful or technological flora of a sample of raw cow's milk from the Relizane region. The isolation of 13 lactic strains, on the basis of a certain number of phenotypic, physiological and biochemical characteristics (fermentation type, growth in the presence of 4% and 6.5% NaCl; growth at pH=4.5 and pH 9.6; growth test at different temperatures 10°C, 37°C, 45°C; study of heat resistance; test of esculin hydrolysis), its different tests have enabled us to identify 4 genera, Lactobacillus 69.23 %, Leuconostoc 15.38%, Enteroccocus 15.38%, Tetragenococcus 7.70%. The API 50 CHL gallery allowed us to identify at the species level: Lactobacillus brevis (4), Leuconostoc mesonteridesssp (2), Enteroccocus faecalis (2), Lactobacillus plantarum (2), Lactobacillus casei (1), Tetragenococcus halophilus (1) Lactobacillus acidophilus(1).