Potential probiotic Lactobacillus plantarum Ln4 from kimchi: Evaluation of β-galactosidase and antioxidant activities

This study was conducted to evaluate the probiotic properties, including beta-galactosidase and antioxidant activities, of lactic acid bacteria isolated from kimchi. Two isolates with a probiotic potential were isolated and identified by 16S rRNA sequence analysis. For comparison, a commercial probiotic strain, Lactobacillus rhamnosus KCTC 12202BP, was used. The isolates, Lactobacillus plantarum Ln4 and G72, and L. rhamnosus KCTC 12202BP, were able to survive under artificial gastric conditions (pH 2.5 in the presence of 0.3% pepsin and 0.3% oxgall). The safety of the LAB strains was tested in terms of antibiotic resistance and production of harmful enzymes. Antibiotic resistance was assessed according to Clinical and Laboratory Standards Institute guidelines. Assessment with the API ZYM kit showed that none of the strains produced harmful enzymes, such as beta-glucuronidase. Among the tested strains, L. plantarum Ln4 showed the strongest adhesion to HT-29 cells and the highest beta-galactosidase activity (3320.99 Miller Units). L. plantarum Ln4 was found to have higher 1-dipheny1-2-picrylhydrazyl radical-scavenging (40.97%) and beta-carotene oxidation-inhibitory activities (38.42%) than did L. rhamnosus KCTC 12202BP. These results suggest that L. plantarum Ln4 isolated from kimchi may have a probiotic potential and could be used in functional foods. (C) 2017 Elsevier Ltd. All rights reserved.