ISOLATION, IDENTIFICATION AND CHARACTERIZATION FOR RESISTANCE TO ACID PH AND PRESENCE OF BILE SALTS OF PROBIOTIC STRAINS FROM COMMERCIAL FERMENTED MILKS

Abstract

The aim of this study was to isolate and to characterize Lactobacillus and Bifidobacterias strains from fermented commercial milks and to analyze its resistance to acid pH and bile salts. The microorganisms were isolated from fermented commercial milks from 'spread-plate' technique in MRS selective medium supplemented with neomycin, paromomicin, nalidixic acid and lithium chloride. After, the strains were characterized as coloration de Gram and catalase test. Were possible to identify through the commercial kit Api 20A microorganisms like Actinomyces israelli, Actinomyces haeslundii, Lactobacillus acidophilus/ jensenii and Bifidobacterium spp 2 and through the commercial kit Api 50CHL Medium were possible to identify the microorganisms Lactococcus lactis ssp lactis 2 and Lactobacillus paracasei ssp paracasei 1. Were realized resistance tests in 3,0; 2,5 and 2,0 pH during 3 and 6 hours and resistance to bile salts in the concentra tion of 0,3%. Both the strains were resistant to 3,0 pH during 3 and 6 hours and to presence of bile salts.