Biopreservative activity of bacteriocin-producing lactic acid bacteria isolated from fermented green gram batter

The biopreservative property of bacteriocin produced by lactic acid bacteria (LAB) from fermented green gram batter was investigated in apple juice and coconut water. LAB was isolated from fermented green gram batter using Man, Rogosa and Sharpe (MRS) media. A total number of four isolates G1, G2, G3 and G4) were isolated from fermented green gram batter. G1 and G2 were identified as Lactobacillus casie and G3 and G4 were identified as Streptococcus species according to Bergeys Manual of Systemic Bacteriology. Antimicrobial activity of the bacteriocin produced by these strains was studied at pH 5 and pH 7 by agar well diffusion method. The bacteriocin produced by these organisms inhibited the growth of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Klebsiella species. The biopreservative efficacy of bacteriocins of G1, G2, G3 and G4 was found both in apple juice and coconut water. The bacteriocins of G1, G3, and G4 exhibited highest antagonistic activity at pH 5 and G2 at pH 7. In apple juice, Minimal Inhibitory Concentrational lactobacillus, streptococcus (MIC) bacteriocin was found to be 25 ul and in coconut water MIC of bacteriocin was found to be 400 ul.