L’effet du pouvoir inhibiteur des bactéries lactiques autochtones isolés du blé fermenté vis-à-vis Lactobacillus plantarum et des bactéries pathogènes de références

Abstract

Lactic acid bacteria are naturally part of our environment and our diet. They are used in the fermentation and bio-preservation of food through the production of organic acids and other antibacterial substances such as bacteriocins by inhibiting certain pathogenic strains. In order to highlight the inhibitory effect of these bacteria, we studied the antagonistic power of 19 lactic isolates isolated from fermented "Hamoum" wheat against a lactic bacterium of the genus Lactobacillus plantarum of pathogenic strains and / or alterations (Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Pseudomonas aeruginosa), according to the method of fleming et al 1975. Purifications of the lactic isolates were performed on MRS medium. Phenotypic characterization tests of these isolates allowed us to identify: 71% Enterococcus sp, 17% Lactobacillus sp, 12% Lactococcus sp. The interactions against pathogenic bacteria lead to the appearance of important zones of inhibition to the largest halo whose diameter is 14 mm. An additional test was necessary to know the exact nature of the inhibitory agent. The results obtained showed that this antibacterial activity can be partially due to lactic acid