虫草素的抑菌活性及机理研究

Study on Antibacterial Activity and Mechanism of Cordycepin

虫草素为蛹虫草等食药保健品的主要活性成分。为进一步评价分析虫草素的抑菌活性及机理,通过最低抑菌浓度及抑菌圈实验测定、扫描电镜观察虫草素对6种常见细菌的抑菌谱及效果,测定供试菌的生长曲线、胞内紫外吸收物质泄露和菌体形态变化,分析虫草素抑制菌体生长及破坏细胞结构机理。结果表明,在溶解度范围内虫草素对3种G~+菌有明显抑菌效果,而对3种G~-菌无明显抑菌效果。生长测定及电镜观察发现经虫草素处理后供试G~+菌菌体形态严重受损,胞内紫外吸收物质外泄,细菌生长进程受阻;而部分供试G~-菌菌体表面有轻微破损并伴随少量内容物泄露,但细菌生长进程不受影响。虫草素具有一定的抑菌选择性,更易破坏G~+菌的壁膜系统起到抑菌作用,对G~-菌整体生长进程无明显影响。

Cordycepin is the main active component of Cordyceps militaris and other food and health products,the purpose of the study is to further evaluate and analyze the main antibacterial activity and mechanism of cordycepin.The bacteriostatic spectrum and effect of cordycepin on six bacteria were determined by minimum inhibitory concentration,bacteriostatic zone test and electron microscopic observation,and the growth curve,intracellular ultraviolet absorption substances leakage and morphological changes of the tested bacteria were further determined to analyze the mechanism of cordycepin inhibiting cell growth and destroying cell structure.The results showed that cordycepin had obvious bacteriostatic effect on three G+bacteria in the range of solubility,but had no obvious bacteriostatic effect on three G-bacteria.Growth assay and electron microscopic observation showed that the morphology of G+bacteria was seriously damaged after cordycepin treatment,the intracellular ultraviolet absorption substances were leaked out,and the bacterial growth process was blocked.While the surface of some tested G-bacteria was slightly damaged and accompanied by a small amount of content leaked,but the bacterial growth process was not affected.Cordycepin presents certain selectivity in bacteriostasis,and it is easier to destroy the wall membrane system of the tested G+bacteria and play a bacteriostatic role,but has no significant effect on the overall growth process of the tested G-bacteria.