Probiotic Potentials of Lactic Acid Bacteria Isolated from Fermented Foods

Abstract

This study investigated the probiotic potentials of seven lactic acid bacteria (LAB) strains at different temperatures, pH, and bile salt concentrations. Their antimicrobial activity and antibiotic susceptibility were also determined. There were significant (P˂0.05) differences in the LAB growth at 45-650C with viable counts ranging from 4.28-8.34 Log10 Cfu/ml after 48 h. The LAB strains showed significant (P˂0.05) increase at pH 2, 2.5 and 3 after 3 and 6 h. L. parabuchneri LMG was viable at 45 and 65oC with 99.30 and 65.00% survival respectively. The LAB showed high resistance to 0.3% bile salt at 97.90%. L. plantarum CIP was viable with 95.40% survival at pH 3.0 after 3 h. All the LAB strains were susceptible to cefuroxime (20 µg/ml) and erythromycin (10 µg/ml) at 13.00-45.00 mm zone of inhibition (ZOI). They had strong antimicrobial activity against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027 and Listeria monocytogenes ATCC 15313. Leuconostoc mesenteroides LM and L. brevis ATCC inhibited the five tested food borne pathogens with ZOI varying from 8.00-26.00 mm. The results from this study showed that the LAB strains isolated from fermented foods had probiotic potential and can be used for research and commercial purposes.