Urification And Characterization Of Bacteriocin Produced By Lactobacillus Coryniformis XN8Isolated From Jiangshui

Microorganism is the main factor lead to food deterioration. It is bad to the flavor,nutrition, color of food. In the food industry, food preservatives (such as sodium benzoate) isoften used to restrain or kill microbes and pathogenic microorganisms in the processing ofcorruption. However these chemical preservatives might inhibit the growth of human bodyskeleton and be harmful to the health of the kidneys, liver. Therefore, natural foodpreservative had become one of hotspots in the field of food research. With the high safetyand antiseptic effect of lactic acid bacteria bacteriocin, it has aroused wide concern.Jiangshui which was popular in Northwest China was a traditional fermented foodgenerally made from vegetables. Generally lactic acid bacteria played an important role invegetable fermentation process.The purport of the study was to purify the bacteriocin produced by lacticacidbacteriaisolated from Jiangshui, and analysis the biochemicalproperties of bacteriocin as well asantibacterial mechanism, at the same time, to explore whether it had the property of as a foodpreservative.The lactic acid bacteria strains with antimicrobial activity were isolated from Jiangshui,thereafter XN8strain with highest antimicrobial activity was selected and it was identified asLactobacillus coryniformis according to16S rDNA sequence blast. The proteineousbacteriocin produced by Lactobacillus coryniformis XN8was purified by the method ofammoniumsulfate precipitation, ion-exchange chromotagraphy and RP-HPLC, by which thebacteriocin was purified, and the molecular weight of the bacteriocin was7343.49Dadetermined by LC-MS. It was found that the bacteriocin had broad antimicrobial spectrum inwhich some antibiotic-resistant food-borne pathogenic strains could be inhibited. Moreover,the bacteriocin shown good stability to resist heat，acid and alkaline. However, the bacteriocinwas sensitive to trypsin, papain, pepsin and proteinase K. According to the results of scanningelectron microscopy (SEM) and transmission electron microscope (TEM), it was shown thatthe bacteriocin might lead to the death of food pathogenic microorganism by damage themembrane of target cell.