瑞士乳杆菌AJT所产抗菌物质的初步研究

Preliminary study on antimicrobial substance produced by Lactobacillus helveticus AJT

从内蒙古地区传统乳制品中分离的瑞士乳杆菌AJT,培养至6h开始具有抗菌活性,20h达到抗菌活性最大值。用甲醇和乙酸乙酯提取的菌株AJT的抗菌物质,排除酸性产物和过氧化氢干扰后,对大肠杆菌等革兰氏阴性菌、金黄色葡萄球菌等革兰氏阳性菌及扩展青霉等真菌具有抗菌活性。抗菌物质经胰蛋白酶、胃蛋白酶、蛋白酶K和木瓜蛋白酶处理后,抗菌活性下降,但仍然具有活性,表明该抗菌物质由蛋白类或非单一类物质组成,在pH2.0～5.0范围内有抑菌活性,对热稳定,对紫外线照射不敏感,属于类细菌素。

Lactobacillus helveticus strain AJT, isolated from traditional fermented dairy samples in Inner Mongolia, China, its antibacterial substance＇ s production increased continuously from 6h, and reached a maximum after 20h. Obtained through ethyl acetate and methanol extraction, the antibacterial substance, had strong antibacterial activity against Gram- positive bacteria such as Staphylococcus aureus, Gram- negative bacteria such as Escherichia coil and fungi such as Penicilfium expansum after eliminating the effect of organic acids and hydrogen peroxide.The active principle was proteinaceous in nature or a mixed substance since the inhibitory activity decreased after treated with trypsin, pepsin, protease K and papain.The inhibitory activity was stable after heating at different temperature for 30min and over the pH range from 2.0 to 5.0, UV light did not affect the activity of the substance,which indicated the antimicrobial substance produced by AJT belong to bacteriocin-like substance.