Development of regression model for bacteriocin production from local isolate of Lactobacillus acidophilus MS1 using Box-Behnken design

Bacteriocins are antimicrobial peptides synthesized by lactic acid bacteria. These are well known for their antibacterial activity in fermented foods and extend the shelf-life and safety of food items. The optimum bacteriocin production was predicted from Lactobacillus acidophilus MS1 using Box-Behnken experimental design. The maximum bacteriocin activity titre of 2600AU/mL was observed with 30 degrees C, pH 6 and 18 h incubation time. The results derived from response surface methodology (RSM) regression equation indicated that the initial pH of the model system influencing stronger than other physical variables at 95% confidence level. Moreover, quadratic and interaction effects of these variables were also found significant. A monomeric peptide of 6.5 kDa was purified to 59.1-fold from crude sample using ion exchange and gel filtration chromatography. Purified peptide showed strong inhibitory activity against biofilm produced by Bacillus cereus, a food born pathogen. Box-Behnken design can be used for large scale production of bacteriocin from novel strain of Lactobacillus acidophilus MS1 that might be used as a preservative and non-allergic antibiotic in food as well as in pharmaceuticals.