植物乳杆菌ST-Ⅲ细菌素类抑菌活性的研究

Study on Bacteriocin Production of Lactobacillus plantarum ST-Ⅲ

以金黄色葡萄球菌10384和肠炎沙门氏菌54001为指示菌,采用牛津杯法和孔扩散法对现有的10余株乳杆菌进行抑菌性能研究。其中,植物乳杆菌ST-III对金黄色葡萄球菌和沙门氏菌两种指示菌都有显著的抑菌作用。植物乳杆菌ST-III在MRS肉汤中生长后获得的无细胞发酵上清液（Cell free supernatant,CFS）在排除有机酸、过氧化氢后,仍具有抑菌活性,表明其发酵上清液中还有其他抑菌物质,可能为细菌素或类细菌素。将无细胞发酵上清液分别与两种指示菌作用一段时间后,采用平板计数法测CFS的杀菌作用。结果表明,植物乳杆菌ST-III所产的类细菌素物质具有较宽的抑菌谱,能够抑制沙门氏菌和金黄色葡萄球菌等多种食品腐败菌和致病菌,在pH 5.0~6.5之间抑菌作用显著。

Over ten Lactobacillus strains were screened for antagonistic activity against Staphylococcus aureus 10384 or Salmonella enteritis 54001 via agar well diffusion method as well as disc diffusion method utilizing stainless oxford cups. Among the tested Lactobacillus strains, Lactobacillus plantarum ST-III demonstrated strong inhibitory activity to the growth of both S. aureus 10384 and S. enteritis 54001. Besides the short chain fatty acids and H2O2, there were bacteriocin-like substances in the cell free supernatant （CFS） of L. plantarum ST-III grown in MRS broth, contributing to the antagonistic activity of the L. plantarum ST-III. Then the bactericidal activity of the CFS to S. aureus 10384 or S. enteritis 54001 were assayed, after co-incubating the CFS with the indicators respectively for different periods. The CFS of L. plantarum ST-III grown in MRS broth demonstrated strong bactericidal activity to S. aureus 10384 in the pH value ranged from 5.0-6.5, whereas there was no obvious bactericidal activity to S. enteritis 54001 for the CFS in the the pH value ranged from 5.0-6.5.