Partial purification, characterization and mode of action of bacteriocins produced by three strains of Pediococcus sp.

The main objective of the study is to assess a comparative antibacterial potential of three new bacteriocins produced by Pediococcus sp. through partial characterization and mode of action against some food spoilage bacteria. The bacteriocins from three different Pediococcus sp. viz. Pediococcus sp. LAB 33 (HQ185406), Pediococcus sp. LAB 41 (HQ185407), and Pediococcus sp. LAB 51 (HQ184064) were partially purified by adsorption-desorption method and tested for autoclave heat, pH, detergent and enzymes stability. A comparative analysis by Tricin-SDS PAGE with MALDI-TOF MS was done to estimate their molecular weight. The mode of action studies were done by cell viability and lactate dehydrogenase assay against two food associated pathogens, viz. Listeria monocytogenes and Pseudomonas aeruginosa using standard protocols. The bacteriocins produced by the strains were resistant to autoclave heat, detergent, wide range of pH and were active against different food borne pathogens at a minimum dose of ~ 100 AU/ml. The mode of action studies showed bactericidal action with lysis of the targeted cells. Therefore, the selective low dose efficacy, heat and detergent stability of the bacteriocins produced by the three strains could be considered as potent bacteriocins for use as food preservatives.