Abstract

ISOLATION, CHARACTERIZATION AND ESTIMATION OF ANTIMICROBIAL ACTIVITY OF NOVEL BACTERIOCIN FROM LACTOBACILLUS CASEI

Arunava Das*, Santanu Sasidharan and Thejus Achuthan

Abstract

Food borne pathogens are continuing to become a matter of great concern in various industries like diary, egg and other food industries. Various gram positive and gram negative bacteria like Salmonella typhi, Bacillus subtilis are the main causative organisms. The present study is based on isolation, identification and screening of major food borne pathogens and novel bacteriocin producing strain of Lactobacillus casei. Investigations were conducted on 389 food samples and from this 12 different genus of bacteria were identified and isolated. From the 62 isolates of Lactobacillus sp. isolated, 9 isolates were Lactobacillus casei and of which 11% (1 isolate) were found capable of producing bacteriocin in large amounts. The isolates were grown for 96 hours under stress condition and the bacteriocin was extracted by centrifugation. Ammonium sulphate precipitation at 70% level of saturation was performed and the precipitate was centrifuged. Well diffusion assay of the extracted protein was performed on different isolated food borne pathogens and the diameter of the zones of inhibition was recorded. The study reveals the extensive scope of bacteriocin as preservatives in the field of food industry and the need for further research in it.

Keywords: Bacillus subtilis, Ammonium sulphate, centrifuged.