144 lactic acid bacteria strains isolated from traditional fermented koumiss were screened for bacteriocin production by double agar diffusion method. After eliminating the effects of organic acid and catalase, the cell free supernatant of one strain named MKB63 showed strong anti-Listeria activity and were identified as Enterococcus faecium by physiological-biochemical characterization. After ammonium sulphate precipitation, dialysis and concentration,the activity was enhanced. But the inhibition activity was lost after treatment of trypsin and proteinase K. The result showed this inhibitory material had the features of protein, and could be classified as bacteriocin.%从内蒙古传统乳制品酸马奶酒中分离出144株乳酸菌,通过双层琼脂平板扩散法筛选出具有明显抑菌作用的菌株.在排除有机酸、H2O2等的干扰后,其中1株乳酸菌的发酵上清液对受试的单核细胞增生李斯特氏菌表现出明显抑制作用;进一步硫酸铵沉淀、透析及浓缩处理后,其抑菌活性显著增强,说明其代谢产物中含有蛋白质类抑菌物质,可能是细菌素.经生理、生化试验和形态学观察,将该菌株鉴定为屎肠球菌(Enterococcus faecium).
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