Functionalities of Lactic Acid Bacteria

The aims of this work were isolate and identify some probiotic strains from human origin, study some characteristics of the identified strains and study the ability of some probiotic LAB to improve the human health. Results revealed: The identified strains using SDS-PAGE technique and API System were: 1 Lb.salivarius, 2 Lb.fermentum, 7 Lb.plantarum, 27 Lb.acidophilus, 1 Lb.brevis, 3 Lb.pentosus, 3 Lb.paracasei ssp.paracasei, 7 E.faecalis, 5 E.faecium, 2 E.durans and 1 Aerococcus viridans. Most of the identified strains were tolerant to the change in pH.32 strains were tolerant to bile salts. Twenty eight strains showed antimicrobial activity against pathogenic E.coli. Ninety-nine strains were tested for their ability to adhere, tested microorganisms exhibited a statistically significant (P<0.05) differentiating adhesion characteristic. 21 strains showed strong adhesion performed In vitro. The effect of 4 probiotic on E. coli was determined In vivo. Administration of E. coli produced adverse clinical signs, whereas administration of probiotic strains enhanced the immune system functions and increased the body weight gain rates in treated groups.