Production, purification, stability and efficacy of bacteriocin from isolates of natural lactic acid fermentation of vegetables

The antimicrobial activity of partially purified bacteriocin produced during natural lactic acid fermentation of carrot, radish and cucumber was assessed and characterized. Out of ten strains, the isolated strain CA 44 of Lactobacillus genus from carrot fermentation produced bacteriocin with maximum antimicrobial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus, though it was more effective against E. coli than others. Bacteriocin was stable at up to 100 degrees C but its activity declined compared to that at 68 degrees C and was completely lost at 121 degrees C. The maximum antimicrobial activity was retained within the pH range of 4-5, but it was adversely affected by the addition of papain. Bacteriocin was also effective against B. cereus in different fruit products (pulp, juice and wine) indicating its potential, application as a biopreservative in fruit products.