Abstract
Background and Aim: In much scientific research, it has been found that antagonistic activity is one of the important properties of a probiotic bacterium to attach in the intestine to reduce attachment of pathogenic bacteria in the intestine. Lactobacillus sp., isolated from fermented dairy products, shows a positive impact on human health. This study was designed to study Lactobacillus sp. isolated from fermented dairy products for their antagonistic activity and probiotic potential.

Methods: In this study, we used the Lactobacilli strain isolated from yogurt samples by a dilution plating method and were screened for their antagonistic activities and potential probiotics. The isolates were tested for their growth in the presence of 0.3% bile salt and pH 2.0 and 3.0.

Results: Out of the 52 strains, 30 strains (60%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Further screening was performed for their growth at 0.3% bile salt. From 30 strains, only ten strains showed tolerance to 0.3% bile salt. Two 2 Lactobacilli strains exhibited antagonistic activity. Moreover, all eight strains were found suitable for the potential probiotic activity, included Lactobacillus casei MU01, MU02, Lactobacillus reuteri MU 113, Bifidobacterium lactis MU85, Lactobacillus salivarius MU18, MU31, Lactobacillus plantarum MU211 3032, and Lactobacillus buchneri MU37.

Conclusions: This study suggests that eight strains showed good antagonistic activity and probiotic potential, which can be used as supplements for good human health.

Key words: Lactobacilli, Probiotic Potential, Antagonistic activity, Lactobacillus buchneri, acid-tolerant