Antibacterial Activity of Lactic Acid Bacteria and Extraction of Bacteriocin Protein

Abstract

Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocin producing Lactobacillus spp. is considered Generally Recognize as Safe (GRAS), useful to control the fast development of pathogens and spoiling microbes in food and feed. Lactobacillus spp. was isolated from traditional winter fermented vegetable cucumber & carrot by the use of selective media. Especially De Man, Rogosa and Sharpe (MRS) Agar media were used to isolate the Lactobacillus species. Morphologically identified by gram staining & colony morphology. Biochemically recognized by catalase, oxidase, MRVP & carbohydrate fermentation test. Antimicrobial activity of Lactobacillus spp. was confirmed by Well Diffusion Method. Molecular characterization of bacteriocin protein and molecular weight determined by SDS PAGE method. The isolate was found to be facultative anaerobic, Gram positive, and catalase negative. The result of antimicrobial activity measured by the Arbitrary Unit (AU/ml) of zone of the inhibition. Six isolates found from the sample but most activities exhibited isolate 4 against Bacillus megaterium (55 mm) zone of diameter. The molecular weight of the washed bacteriocin was calculated to be about 40 kDa (Isolate 1) and 15 kDa & 30 kDa (Isolate 5). Bacteriocin protein reduces chemical preservatives and uses in future as biopreservative in food industry.