Production of bacteriocin and their application in food products

Objective: To isolate bacteriocin- producing lactic acid bacteria (LAB) and to asses its preservative effects on food products. Methods: Lactobacillus strain was isolated from chicken intestine using MRS broth (Hi-Media, India) at 37 °C for 48 h. The isolate was identified by 16s rRNA sequencing and phylogenetic analysis. Bacteriocin was produced, purified by ammonium sulphate precipitation and dialyzed. Antagonistic characteristics of bacteriocin were studied by agar well diffusion method. Bacteriocin stability was studied in different temperature, pH and enzymes. Biopreservative efficacy was determined for fish and fresh juice. Results: Lactobacillus
fermentum (L. fermentum) strain isolated from chicken intestine was capable of producing bacteriocins, inhibiting the widest range of pathogenic bacteria. The bacteriocin was stable at 37 C and acidic pH and proteinaceous in nature. Their biopreservative effect on refrigerated food products (apple juice and fish) show low count of colonies. Lactobacillus isolate was sequenced which shows high similarity with reference strain L. fermentum CECT 5716. Conclusions: Bacteriocin producing L. fermentum UN01 could be successfully used as biopreservative and to increase the shelf life of the food products.