10-HDA对枯草芽孢杆菌的抑菌机理研究

Antibacterial Activity and Mechanism of Action of 10-HDA against Bacillus subtilis

摘要:

为了确定与分析10-羟基-2-癸烯酸（10-HDA）的抑菌性能及其作用机制，采用牛津杯法，倍半稀释法进行抑菌性能测定实验。以枯草芽孢杆菌为供试菌，采用凝胶阻滞实验及原子力显微镜观察10-HDA与菌体DNA结合情况，并采用DNA琼脂糖凝胶电泳观察10-HDA作用后菌体DNA含量的变化，以及10-HDA对菌体基因组PCR的影响。结果表明，10-HDA对多种病原细菌具有明显的抑制作用，表现出广谱抗菌活性，且抑菌效果随着10-HDA浓度的增加显著提高。其中，对枯草芽孢杆菌的最小抑菌浓度（MIC）为0.62 mg/mL。DNA琼脂糖凝胶电泳和原子力显微镜结果显示，当10-HDA浓度达到0.62 mg/mL时，菌体中基因组DNA的合成量明显减少，而且10-HDA与细菌基因组DNA紧密结合。对基因组DNA的PCR影响实验进一步证明，当PCR体系中10-HDA的浓度达到1.0 mg/mL时，DNA的合成被完全阻碍。通过实验，我们得出10-HDA通过与细菌基因组DNA的结合，进一步阻碍DNA的合成，最终达到抑菌效果。

Abstract:

Through oxford cup test and half dilution method for testing antibacterial activity, the preparation progress and antibacterial activity of 10-HDA against Bacillus subtilis were identified and analyzed in this paper. The quantity and bonding of bacteria DNA affected by 10-HDA were analyzed by using atomic force microscope (AFM) and agarose gel electrophoresis of DNA. The results showed that, 10-HDA was a broad-spectrum antimicrobial agent and had obvious inhibition effects on multiple pathogenic bacteria with a concentration-depended mode of inhibitory effect. The minimum inhibitory concentration (MIC) of Bacillus subtilis was 0.62 mg/mL. Agarose gel electrophoresis and AFM analyses revealed that the synthesis of DNA was rapidly decreased due to the close combination with 10-HDA. It was further proved by its impact on PCR of DNA that the synthesis of DNA could be completely impeded when the mixing concentration of 10-HDA was 1.0mg/ml. Therefore, bacteriostatic action was inferred to be caused by the combination between 10-HDA and DNA which inhibited the replication of DNA.