DOI: 10.36347/sajb.2014.v02i12.005

Pages: 871-876

Lactobacillus, widely studied lactic acid bacteria (LAB), are very common inhabitants of milk from different sources such as cow milk, goat milk, buffalo milk, etc. Our target was to isolate some Lactobacillus spp. from buffalo milk and evaluate their antimicrobial activity. We selected buffalo milk as our sample with an expectation that it may contain Lactobacillus spp. with some better qualities because of it’s high protein and mineral levels and low cholesterol contents. Ten (10) buffalo raw milk samples, collected from different regions of Chittagong district of Bangladesh, were tested for isolation and identification of Lactobacillus spp. Isolates showing antimicrobial activity against any two of the eight selected Gram positive and Gram negative pathogenic bacteria were considered as potential. Two potential Lactobacillus spp. from 22 primary isolates were selected on the basis of their antimicrobial activity by cross streak method. The selected potential isolates were identified as Lactobacillus brevis(B34) and Lactobacillus fermentum (B73). Lactobacillus brevis showed activity against Staphylococcus aureus and Pseudomonas aeruginosa where as Lactobacillus fermentum against Shigella dysenteriae and Bacillus subtilis. It was also observed that both identified Lactobacillus spp. show their best antimicrobial activity against these pathogenic bacteria after incubation at 37˚C temperature for 24 hours. Both the species were tested for their bacteriocin activity against the respective pathogenic bacteria. From our present study, it is revealed that Lactobacillus spp. from buffalo milk has some probiotic properties and can be considered for use against various human pathogens.