1株产广谱细菌素乳酸菌的筛选及其抑菌物质的特性

从植物性材料中筛选到1株对大肠杆菌有明显抑制作用的乳酸菌,在排除有机酸和过氧化氢的干扰后,该菌株的发酵上清液仍有较强的抑菌性;胃蛋白酶处理后,抑菌活性明显降低,说明其抑菌物质为蛋白质类物质,是一种细菌素。通过形态学和生理生化分析,初步鉴定该菌株为植物乳杆菌。生物学特性研究表明,该菌株发酵上清液经高温、吐温-80、SDS、EDTA处理后,仍保持较好的抑菌活性;在酸性条件下稳定;对蛋白酶K和胰蛋白酶较胃蛋白酶敏感。抑菌谱显示,该菌株的发酵上清液具有广谱抑菌性。

Screening of Broad-spectrum Bacteriocin-producing Lactic Acid Bacteria Strain and Characteristics of Antibacterial Compounds

By A broad spectrum bacteriocin producing strain was screened by plant punching and its antibacterial characteristics was studied.The results showed that one bacteriocin-producing Lactic acid bacteria strain isolated from plant materials exhibited strong inhibition activity against the E.coil.The supernatant of this strain could still inhibit the growth of indicator strain strongly after eliminating hydrogen peroxide and organic acid.After treatment with pepsin,the strain's inhibitory activity decreased sharply,which showed the inhibitory substance possessed the characteristic of protein,and it could be named bacteriocin.The strain was identified as Lactobacillus plantarum through detection of its appearance,physiological and biochemical characteristics.The inhibitory activity of strain fermentation supernatant was not affected by high temperature,1% Tween-80,SDS,EDTA and the low pH.However,its inhibitory activity revealed an obvious decrease after treatment with protease K and trypsin than with pepsin.The bacterial inhibition spectrum showed that this was a kind of bacteriocin with wide inhibition spectrum.