Purification And Partial Characterization Of Plantaricin Y Produced By Lactobacillus Plantarum Y

Bacteriocins from variety Lactobacillus plantarum have beneficial effects on health protection, which can used as food preservatives to improve food safety. Studies on characteristic and purification of plantaricin Y provided a good theoretic basis for intensive study. The results were described as follows:1. Characterization of plantaricin YPlantaricin Y kept active between pH3to pH5.; plantaricin Y was stable under the high temperature due to the result that the residual activity was beyond80%when it was treated100℃for30min, and the residual activity was beyond75%under the high temperature of121℃for30min; it was completely inactive when treated by pepsin, chymotrypsin and trypsin, while partial inactive when treated by proteinase K and lipase. The results revealed that plantaricin Y would be a kind of lipoprotein.2. The determination of plantaricin Y’s inhibitory spectrumPlantaricin Y has a broad inhibitory spectrum which can inhibit various Gram positive bacteria such as Lister monocytogenes, Staphyloccocus aureus, Bacillus thuringiensis and Gram negative bacteria such as Escherichia coli, Proteus sp, Salmonella pullorum, Pseudomonas aeruginosa. But no inhibitory spectrum against molds. Studying on the mode of action against Salmonella pullorum, it showed that plantaricin Y could kill the cells.3. The purification of plantaricin YThe methods of crude sample preparation and processing of plantaricin Y were studied. After centrifugation the supernatant of fermentation liquid was purified by60%saturation (NH4)2SO4, dialysis and Sephadex G25column chromatography. The purification fold and the yield of plantaricin Y were3.94and3.2%, respectively.