一株乳酸乳球菌所产细菌素的生物学特性

Biological Characteristics of Bacteriocin Produced by Lactococcus lactis subsp. cremoris

对乳酸乳球菌KLDS4.0326所产类细菌素进行分离纯化,并对细菌素的部分生物学特性进行研究。在排除酸性产物和过氧化氢的干扰后,菌株的无细胞发酵上清液对金黄色葡萄球菌和枯草芽孢杆菌等革兰氏阳性细菌以及大肠杆菌、沙门氏菌等革兰氏阴性细菌具有显著的抑制作用;经胰蛋白酶、胃蛋白酶、木瓜蛋白酶和蛋白酶K处理后,抑菌活性降低,表明抑菌成分为蛋白类物质;该细菌素具有良好的热稳定性,在酸性条件下抑菌活性稳定,并且具有较广的抑菌谱,能够抑制多种革兰氏阳性细菌和革兰氏阴性细菌。

A bacteriocin-producing lactic acid bacteria strain was isolated from traditional dairy products in Inner Mongolia, and was identified as Lactococcus. lactis subsp, cremoris KLDS 4.0326. Bacteriocin produced by KLDS 4.0326 was partially purified and its characteristics were also preliminarily studied. The cell-free fermentation supernatant of strain KLDS 4.0326 with the exception of interferences from acidic products and hydrogen peroxide had potent inhibitory effects on both Gram- positive bacteria （Staphylococcus aureus and Bacillus subtilis） and Gram-negative bacteria （Escherichia coli and Salmonella）. After treatment with trypsin, pepsin, papain or proteinase K, its inhibitory activity decreased, indicating that the antibacterial component was protein. This bacteriocin showed good thermal stability and stable antibacterial activity under acidic conditions, and had a broad antibacterial spectrum against various species of Gram-positive bacteria and Gram-negative bacteria.