绿色木霉菌发酵液萃取物对金黄色葡萄球菌细胞膜的损伤作用

Effect of Extract from Trichoderma viride Fermentation Broth on Cell Membrane Injury of Staphylococcus aureus

研究绿色木霉菌发酵液的萃取物对金黄色葡萄球菌的抑制活性,及其对细胞膜的损伤作用。通过抑菌实验、细胞裂解率测定、细胞膜渗透性测定、SDS-PAGE蛋白谱变化等对绿色木霉菌发酵液萃取物的抑菌活性和其对细菌细胞膜损伤的作用进行研究。石油醚、乙酸乙酯以及正丁醇萃取物对金黄色葡萄球菌均有抑制活性,其中,正丁醇萃取物的抑菌活性最强,抑菌圈直径(25.27±0.65)mm,最低抑菌质量浓度(MIC)为0.625mg/mL。经过正丁醇萃取物处理后,菌体细胞裂解率增加,细菌培养液的电导率、蛋白质以及还原糖含量显著增加,SDS-PAGE分析证明正丁醇萃取物可以阻碍金黄色葡萄球菌细胞膜蛋白质的正常表达。正丁醇萃取物可破坏金黄色葡萄球菌细胞膜的结构,导致细胞膜通透性增加,改变细胞膜功能,从而抑制其生长。

This study investigated the antibacterial activity of different extracts from T. viride fermentation broth and its damage to the cell membrane of Staphylococcus aureus. The antibacterial activity was evaluated by Oxford plate method, the proportion of Staphylococcu aureus cell lysis was determined and the damage to the cell membrane was evaluated by determining membrane permeability and SDS-PAGE. Petroleum extract, ethyl acetate extract and n-butanol extract from T. viride fermentation broth exhibited antibacterial activity, especially n-butanol extract （d = （25.27 ± 0.65） mm, MIC = 0.625 mg/mL）. After treated by n-butanol extract, the proportion of cell lysis, electric conductivity, protein and reducing sugar content of Staphylococcus aureus culture suspension increased significantly. SDS-PAGE assay demonstrated that n-butanol extract could interfere with cell membrane protein expression in Staphylococcus aureus. In addition it could damage the structure of cell membrane, resulting in an increase in the cell membrane permeability and disorders of cell membrane function. Thus, the growth of Staphylococcus aureus was inhibited.