ABSTRACT
Minas artisanal cheese is made from endogenous starter cultures, including lactic acid bacteria (LAB). Some LAB may possess probiotic potential. Thus, this study aimed to evaluate the in vitro probiotic properties of lactobacilli isolated from Minas artisanal cheeses produced in Minas Gerais. Ten samples of lactobacilli, formerly isolated from those cheeses, were submitted to the following assays: antimicrobial susceptibility, tolerance to artificial gastric juice and biliary salts, production of hydrogen peroxide and antagonism against pathogenic and non-pathogenic micro-organisms. Only L. plantarum (C0) was sensitive to all tested antimicrobials, while the other LAB samples were resistant to at least one drug. Six samples were tolerant to artificial gastric juice, and L. brevis (A6) even grew in that medium. Three samples were tolerant to biliary salts. Only L. brevis (E35) produced hydrogen peroxide. Difference (P< 0.05) was observed among the means of inhibition haloes of lactobacilli against Enterococcus faecalis ATCC 19433 and Lactobacillus plantarum C24 in spot-on-the-lawn assay. All samples of lactobacilli inhibited Escherichia coli ATCC 25922, Salmonella enterica var. Typhimurium ATCC 14028 in co-culture antagonism test (P< 0.0001). Most lactobacilli samples showed in vitro probiotic potential. From the tested samples, L. brevis (A6) presented the best results considering all in vitro probiotic tests.
Keywords:
artisanal cheeses; beneficial micro-organisms; antibiogram; tolerance to gastric juice and biliary salts; antagonism