Prevalence of Lactobacillus Acidophilus in Milk Samples and their Bacteriocin Activity

Lactobacillus acidophilus, a prominent lactic acid forming bacterium, which plays a significant role in the dairy industry. The present study was undertaken to isolate, characterize, and identify L. acidophilus strains from milk samples collected from different locations in Goa. A total 22 isolates were obtained Higher prevalence of bacterial isolates was, however, observed in cow milk (14 isolates) as compared to those in buffalo milk (8 isolates). All isolates were Gram-positive, rod-shaped, and non-motile. Fermentation caused by these bacterial isolates could metabolize a range of carbohydrates, including fructose, arabinose, lactose, and sucrose. Biochemical assays indicated the absence of enzymatic activities for indole, citrate, and Voges-Proskauer, while esculinase and gelatinase activities were positive. One of the isolates (LA-11) demonstrated antimicrobial activity against Staphylococcus aureus and Streptococcus agalactiae. Isolates of L. acidophilus exhibit probiotic and antibacterial properties, which enable their use in food safety, dairy products, and gut health.