Purificaiton And Partial Characterization Of The Bacteriocin Produced By Lactobacillus Pentosus LPEM818

Bacteriocins were used as food preservative, which were to impove food safety. And the homogeneity bacteriocins are necessary for the studies of biochemical and genetic characterization. The partial purification and characterization of pentocin LPEM818produced by Lactobacillus pentosus LPEM818were studied.1、Pentocin LPEM818exhibited inhibitory activity against part of the Gram-positive bacteria such as Staphylococcus aureus, Micrococcus tetragemts, Bacillus thuringiensis, Listeria monocytogenes, L. innocua and Gram-negative bacteria such as Escherichia coli, Proteus sp., Pseudomonas aeruginosa, Salmonellapullorum and so on.2、The activity of pentocin LPEM818was destroyed after treatment with proteinase K and trypsin, but not when treated with papain, lipase, catalase, pepsin and a-chymotrypsin. It remailed activity in Triton X-100, Tween-80and acetonitrile but lost activity when was treated by urea. The results revealed that the antimicrobial compound would be a kind of protein.3、Pentocin LPEM818exhibited strong heat stability (remained84.52%of the antibacterial activity after15min at121℃) and pH stability (pH2.0-8.0).4、The mode of action of pentocin LPEM818was bactericidal and production of Pentocin LPEM818during growth of L. pentosus LPEM818were studied. L. pentosus LPEM818began to produce Pentocin LPEM818at the middle of the logarithmic phase at37℃. Its yield reached the highest value at the late of the stationary phase during the fermentation process. Then the production of Pentocin LPEM818kept stable.5、The methods of crude sample preparation and processing of Pentocin LPEM818were studied, what is more, the optimization condition of gel filtration chromatography, ion exchange chromatography and hydrophobic interaction chromatography.6、The molecular weight of Pentocin LPEM818was approximately5kDa by Tricine-SDS-PAGE analysis.The identified properties of pentocin LPEM818indicate that it is a novel bacteriocin with potential application as a bio-preservative to improve the safety of food products.