一株植物乳杆菌的鉴定及其抑菌特性研究

Identification of a Lactobacillus plantarum and analysis of its antibacterial properties

从内蒙古传统发酵乳制品中分离筛选到1株具有抑菌活性的乳酸菌。通过API生化反应和16S rDNA、16S-23S rDNA间隔(IGS)序列同源性分析,鉴定该乳酸菌为植物乳杆菌(Lactobacillus plantarum),并命名为植物乳杆菌NDC 75017。利用杯碟法,通过蛋白酶K和胰蛋白酶实验,确定该乳酸菌产生的抑菌物质为蛋白质类。理化性质分析表明该抑菌物质具有良好的热稳定性,100℃处理120 min后仍有较好的抑菌活性;其抑菌活性最适pH值范围为2～4;通过排除有机酸、过氧化氢的干扰,该菌的发酵上清液对单增李斯特菌、藤黄微球菌、蜡样芽孢杆菌及福氏志贺氏菌的生长具有良好的抑制作用。

A lactic acid bacteria isolated from traditional dairy products in Inner Mongolia of China exhibited antibacterial ability. By API bio- chemical methods and analysis of 16S rDNA and 16S-23S intergenic spacer region （IGS） gene sequence, the strain was identified as Lactobacil- lus plantarum and named as L. plantarum NDC 75017. The reduction in antimicrobial activity was observed after treatment with proteinase K and trypsin by cylinder plate method, demonstrating its proteinaceous nature. The bacteriocin showed high temperature stability up to 100 ℃ for 120 min and had less loss in its activity and stability in the range of pH 2-4. After eliminating some interference factors including the or- ganic acids and hydrogen peroxides, the bacteriocin still evidenced antibacterial activity against Listeria monocytogenes, Micrococcus luteus, Bacillus cereus and Shigella flexnri.