Determination of antibacterial Activity of Bacteriocin of Lactic Acid Bacteria Isolated from Meat Samples

Abstract

The present study is aimed at determination of antimicrobial activity of lactic acid bacteria isolated from meat samples against common food borne pathogens. The meat samples were collected from local meat shops and were inoculated in sterile saline to make suspension. The isolates were enriched in tomato juice at acidic pH and then the bacteriocin producing lactic acid bacteria were isolated by using de-Man Rogosa Sharpe (MRS) agar supplemented with 0.01% sodium azide and 2%  Glycerophosphate. The plates were overlaid with the same media and incubated at 35 oC for 48- h. The production of crude bacteriocin was carried out by growing isolated strain in MRS broth, which was then centrifuged at 10000 rpm for 15 min at 4 oC to get the bacteriocin fraction in the cell free supernatant. The crude bacteriocin preparation was subjected to characterization with respect to heat stability, pH, susceptibility to denaturation by enzymes and detergents. Antagonistic activity of bacteriocin was studied by agar well diffusion method against different microorganisms such as B. subtilis, B. cereus, S. typhi, M. luteus, S. aureus, E.coli and P vulgaris. The result showed that bacteriocin producing lactobacilli obtained from meat samples have potential to inhibit bacteria such as B.cereus, S. typhi, S. aureus, E.coli, P. vulgaris.