一株粪肠球菌8-1所产抑菌物质的生物学特性研究

为获得具有应用潜力的抑菌活性菌株,本实验采用双层琼脂平板扩散法对内蒙古传统乳制品酸马奶中分离的一株粪肠球菌（Enterococcus faecalis）8-1进行研究。排除有机酸和过氧化氢的干扰后,其无细胞发酵上清液对指示菌单核增生李斯特氏菌（Listeria monocytogenes）有明显的抑菌作用。且经过胰蛋白酶、蛋白酶K、胃蛋白酶和木瓜蛋白酶处理后,抑菌活性几乎完全丧失,表明该抑菌物质是蛋白类物质。该抑菌物质在酸性条件下抑菌活性明显,且具有良好的热稳定性。对有机溶剂、金属离子、紫外线不敏感,与SDS和EDTA共同作用抑菌效果增强。有较广的抑菌谱,能抑制多种革兰氏阳性菌和革兰氏阴性菌,初步推断属于类细菌素。 

Biological characteristics of antimicrobial substance produced by Enterococcus faecalis 8-1

For obtaining application potential antibacterial activity strains,Enterococcus faecalis 8-1 isolated from traditional fermented dairy kouminss in Inner Mongolia by the double agar diffusion method. After eliminating the effects of organic acid and catalase, the cell- free fermentation supernatant showed strong anti- Lister activity. After treatment with trypsin,pepsin,papain and proteinase K,its inhibitory activity destroyed,indicating that the antibacterial component was protein. This antibacterial substance showed stable antibacterial activity under acidic conditions andgood thermal stability. Organic solvents,metal ions and UV light did not affect the activity of the antibacterial substance,inhibitory activity enhanced with the combination of SDS and EDTA,and had a broad antibacterial spectrum against various species of Gram-positive bacteria and Gram-negative bacteria,which preliminary analysised the antimicrobial substance produced by 8-1 belong to bacteriocin-like substance.