产细菌素植物乳杆菌菌株的筛选及其细菌素生物学特征研究

从甘蓝泡菜中分离到６９株乳酸杆菌，通过琼脂点扩散交叉拮抗试验，筛选出３株有明显抑菌活性代谢产物的植物乳杆菌。排除酸、过氧化氢等干扰因素后，离心发酵液对指示菌Ｌａｃｔｏｂａｃｉｌｕｓｐｌａｎｔａｒｕｍ９６Ｄ仍有抑菌作用，用胰蛋白酶对其透析液处理后活性丧失，说明它们产生的抑菌物质是细菌素。以Ｇ８菌株为试材，对其细菌素类物质的产生及细菌素粗提物进一步研究，发现在对数末期其抑菌活性最高，对热相对稳定（１００℃，２０ｍｉｎ），易被胰蛋白酶、蛋白酶Ｋ和胃蛋白酶失活，显示活性的ｐＨ值范围为４．０～５．５，粗提液表现为不仅抗明串株菌属、片球菌属、乳杆菌属的一些菌株，而且抗一些非乳酸菌的革兰氏阳性菌，但对大肠杆菌（Ｅ．ｃｏｌｉ）等革兰氏阴性菌没有任何抑制作用。说明Ｇ８菌株产生的是一类抗广谱革兰氏阳性菌的细菌素

Screening of Bacteriocin producing Lactobacillus plantarum Strain and Studying on Biological Characteristics of Bacteriocin

Lactobacillus strains were isolated from cabbage pickles. Among them, three Lactobacillus plantarum strains were screened out to exhibit inhibitions to other strains through agar drop diffusion cross antaganistic test. The supernatants of fermented liquor without the organic acids and hydrogen peroxide showed to inhibit the growth of Lactobacillus plantarum 96D, an indicator strain. But the inhibition activity was lost after treatment of trypsin. Therefore, the inhibition substance could be classed as bacteriocin. G 8 strain was selected for further research. Maximum production of the inhibitory compound was obtained in the late log period in MRS medium. The inhibitory compound was heat stable (20 min at 100℃), active in the pH 4.0￣4.5, but sensitive to several proteases including trypsin,protease K, pepsin.The G 8 strain crude extract showed inhibition to some gram positive bacteria, including non LAB as well as some strains of Pediococcus,Leuconostoc,Lactobacillus . In contrast,no inhibition activity to gram negative bacteria such as E. coli etc. was detected.