Antibacterial efficacy of nisin and pediocins against food spoilage and pathogenic organisms in broth and a vegetarian food

Abstract

Antibacterial efficacy of bacteriocins from Pediococcus acidilactici (PA) and P. pentosaceous (PP) and nisin was evaluated individually and in combination against several Gram-positive and Gram-negative food spoilage and pathogenic organisms in liquid medium by pour plate method. Nisin was found to be a potent inhibitor of Clostridium sporogenes, while the bacteriocins from PA and from PP were potent against Listeria monocytogenes and Staphylococcus aureus. Gram-negative organisms were resistant except for suppressing the growth of E. coli until 24 h by PA or PP and Pseudomonas by PA or PP or nisin until 72 h of incubation at the highest concentrations (320 AU/ml). The combination treatment showed a synergistic effect in case of C. sporogenes and S. aureus while more of an additive effect against L. monocytogenes. The efficacy of these bacteriocins was also evaluated individually and in combination against L. monocytogenes and S. aureus in a vegetarian food model system. The bacteriocin from PA followed by PP was found to be more effective against L. monocytogenes and 5. aureus as compared to nisin. However, the combination of PA with nisin proved to be more beneficial as there was maximum inhibition of both the organisms and no bloating of the sealed pouches was observed up to 14 days.