The Effect of Pediococcus pentosaceus Bacteriocin on Listeria monocytogenes in Soft Cheese

─Among antimicrobial materials produced by Pediococcus pentosaceus, bacteriocin have gained the greatest interest in food preservation as a natural substance. A bacteriocin producing P. pentosaceus was isolated from vegetables and human stool in a previous study. Purification, activity measurement, and characteristics of the bacteriocin was also determined. The yield of the bacteriocin was 9.08% and the specific activity was 11266.667 Au/mg. The specific activity was increased by 15322 fold and the molecular weight was 39KDa.The antimicrobial activity assay against Listeria monocytogenes was measured by agar well diffusion method. Different concentrations had prepared of crude and purified bacteriocin and the most effective one was the purified bacteriocin at a concentration 1000 ub/ml. The highest antilisterial activity of the crude bacteriocin in soft cheese was at concentrations 2000 and 1000 ub/ml at the tenth day which was 1.5 and 1.9 CFU/ml alternately. So, P.pentosaceus bacteriocin showed significant activity against L.monocytogenes Keyword─bacteriocin, Listeria monocytogenes, Pediococcuspentosaceus, soft cheese