Physiological, biochemical and molecular characterization of potential bacteriocin producing strain isolated from fermented berseem

Abstract

Lactic acid bacteria in fermented foods help in the improvement of flavour, preservation of the nutritive values of the raw material, and inhibition of growth or killing of food spoilage and pathogenic bacteria. Beside other metabolites, the produced bacteriocin, which is a ribosomally synthesized antimicrobial peptide, is the major metabolite involved in the killing of food spoilage microorganisms and acts as a biopreservative. In search of a bacteriocin having specific inhibitory activity against food pathogenic bacteria, isolation of bacteriocin producing lactic acid bacteria from various food items was carried out. Based on maximum production of the bacteriocin, strain BS13 was characterized and was further identified as Enterococcus faecium BS13 on the basis of physicochemical properties and 16S rRNA analysis. In MRS medium this isolate presented the maximum production of bacteriocin (27 306 AU ml−1) after 18 h of incubation period. BS13 bacteriocin showed antimicrobial activity against a wide range of bacteria, including Bacillus subtilis, Staphylococcus sp., Pediococcus sp., Listeria monocytogenes and Lactobacillus sp.