Antimicrobial Activity of Lactobacillus spp. Isolated from Traditional Curd (Sangom Aphamba) Against Selected Pathogens

Traditional Manipuri curd (Sangom aphamba) is considered a rich source of probiotics. The genus Lactobacillus comprises a large group of beneficial bacteria that produce lactic acid as the end product of fermentation. The present study focuses on the isolation and analysis of the the antimicrobial activity of Lactobacillus spp. from traditional curd samples. A total of five curd samples were collected from Khangabok (LS1K), Haorang Keirel (LS2HK), Oinam (LS3O), Mayang Imphal (LS4MI) and Sanjenbam (LS5SJ), along with one laboratory prepared curd sample (LS6LMS). Isolation was carried out using MRS (de Man, Ragosa, and Sharpe) agar, followed by purification through repeated streaking. Based on the morphological and biochemical characteristics of the isolates, six strains of Lactobacillus spp. were identified. The isolates were evaluated for antagonistic activity against Micrococcus luteus (MTCC 106), Bacillus subtilis (MTCC 121) and Escherichia coli (MTCC 739). The isolates exhibited notable antimicrobial activity against M. luteus and E. coli, while no inhibition was observed against B. subtilis. Among the isolates, LS5SJ demonstrated the highest zone of inhibition (14.5mm) against E. coli, followed by LS2HK (13.5 mm) and LS1K (11 mm). The findings suggest that traditional curd (Sangom aphamba) contains Lactobacillus spp. with significant antagonistic properties, supporting its role as a beneficial food.