Probiotic Potential of Lactobacillus plantarum LD1 Isolated from Batter of Dosa, a South Indian Fermented Food.

Lactobacillus plantarum LD1 was isolated from dosa batter and identified by biochemical, physiological and genetic methods. Species level identification was done by 16S rDNA amplification and sequencing. The probiotic potential of strain LD1 was assessed by different standard parameters. Cell surface hydrophobicity was recorded to be 62% with SAT value <0.007 M. Seventy-eight percent of viable count was found after treatment with simulated gastric juice containing pepsin (pH 2.0). Bile salt tolerance and bile salt hydrolase activity were also demonstrated by strain LD1. The culture supernatant was able to inhibit food-borne as well as clinical pathogenic microorganisms such as Staphylococcus aureus, Salmonella typhimurium, Shigella flexneri, Pseudomonas aeruginosa, urogenic Escherichia coli and Vibrio sp. Strain LD1 was found to be sensitive to most of the antibiotics used in the study. Since strain has been isolated from food source that is most typical of Southern India, it would be safe for further consumption in probiotic products.