Isolation and characterization of potential probiotic lactic acid bacteria from traditional cheese

Abstract

A total of 25 traditionally procured white cheese were collected from the Samsun region in Turkey. Selected physicochemical and microbiological characteristics of the cheese were screened via classical analysis and significant differences were detected between cheese samples. In this study, twelve lactic acid bacterial isolates with high antimicrobial activity from these cheeses were selected for further analysis. Isolated strains were identified and characterized by phenotypic and genotypic methods, and their probiotic and industrial properties were studied. Nine of the isolates were identified as enterococci (4 E. durans, 3 E. faecium, 1 E. faecalis and 1 E. gallinarum). Other identified strains included 2 Lactiplantibacillus pentosus, and 1 Loigolactobacillus coryniformis subsp. torquens. A series of established in vitro tests were conducted to determine the probiotic potential of isolates. These tests include bile and gastric juice tolerance, antibiotic resistance, ability to survive at different temperatures, pH ranges, and salt concentrations, acid-producing ability, proteolytic activity, β-galactosidase production, and the ability to produce gas from glucose. The results of the study suggested that the E. faecium S1113, E. durans S104, E. durans S1121, and E. durans S202 isolates have potential use as novel probiotic strains in the food industry.