Etude De L’activité Antibactérienne Des Lactobacillus Isolées À Partir Du Lben Traditionnel Provenant De La Commune De Ben Srour (m'sila) À L’égard Des Quelques Souches Pathogènes Ciblées

Résumé: In Algeria, as in the other countries of the world, there are indigenous dairy products whose production method derives from the cultural heritage of the population. These products are derived from the transformation of milk in order to extend its shelf life. Among the traditional Algerian milk preparations: Zebda, Lben, Dhan which can be sources of lactic acid bacteria which have inhibitory activities with respect to pathogenic germs. So they constitute a line of defense through the production of lactic acid, hydrogen peroxide and bacteriocins. In this study, 120 strains of lactic acid bacteria were isolated from the traditional Lben. The phenotypic identification by morphological and biochemical tests showed that seven strains belonged to the genus Lactobacillus. The identification by the fermentation profile led to different species as: M1: Lactobacillus plantarium, M2: Lactobacillus helveticus, M3: Lactobacillus acidophilus, M4: Lactobacillus fermentum, M5: Lactobacillus casei subsp.tolerans, M6: Lactobacillus rhamnosus, M7: Lactobacillus alimentarus. The 7 strains were tested for their antibacterial effects against Staphylococcus aureus, Escherichia coli and Bacillus subtilis. The interaction of our lactic strains with pathogenic bacteria was detected by well diffusion technique on agar medium including forming halos around wells indicates the presence of inhibition. From the results we note that the strains M1 and M2 having antibacterial activity against strains, Staphylococcus aureus and Bacillus subtilis. The measurement of inhibition diameters reveals diameters which range from 1 to 5 mm. While the other strain exhibits no antibacterial activity against the pathogenic strains used. The effect of bacteriocins is also realized as a heat-sensitive protein substance is responsible for inhibition of pathogenic strains used.

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