PROBIOTIC PROPERTIES AND ANTIOXIDANT EFFICIENCY OF LACTOBACILLUS PLANTARUM 15 ISOLATED FROM MILK

Many researchers are focusing on the investigation of new molecules and substances to help the body fighting oxidative stress; among them are probiotic bacteria. In this study we investigated the probiotic properties and the antioxidative activity of Lactobacillus plantarum 15 isolated from milk. Therefore, to evaluate probiotic potential of the selected strain, the antibacterial activity and resistance to acidic pH and bile salts conditions were evaluated. Moreover, several methods were used to analyze the antioxidant potential of this strain. The evaluation of probiotic properties showed that Lb. plantarum 15 resists to acidity and to bile salts (survival rate was 86.40% and 80.58%, respectively). The isolate showed a broad inhibitory activity against several bacterial strains. The antioxidant potential assessed by the DPPH method showed that Lb. plantarum 15 cells as well as the cell-free supernatant have important scavenger effect (82.65% and 72.21%, respectively). Furthermore, the strain showed a good resistance to hydrogen peroxide (76.12%), hydroxyl radicals (46.15%) and a considerable iron chelating ability (20.52%). Thus, Lb. plantarum 15 could be effectively considered as potent antioxidant probiotic food supplement.