水蒸气蒸馏法提取茜草精油抑菌活性及其机理的研究

Study on the Antibacterial Activity and Its Mechanism of Essential Oil from Madder(Rubia cordifolia L.) Extracted by Hydrodistillation

以滤纸片及刃天青法测定受试菌抑菌圈直径及MIC、MBC,为水蒸气蒸馏法提取所得茜草精油的抑菌活性提供依据;另外,通过受试菌在受到精油作用后生长曲线、电导率及表面超微结构的变化初步研究了精油的抑菌机理。抑菌圈、MIC和MBC结果表明:精油对G+(表面葡萄球菌)和G-(痢疾杆菌)效果较强;对G+(枯草芽孢杆菌)和G-(大肠杆菌)效果较弱。生长曲线、细胞膜通透性及细菌细胞超微结构的研究结果表明:抑菌机理可能源于茜草精油能有效地抑制细菌的对数生长期分裂速度,导致细胞膜渗透性的增加。

Diameter of inhibition zones （DIZ）,MIC ＆ MBC detection via filter paper disk and Resazurin method were investigated on essential oil from the the Rubia Cordifolia L. （REO） to provide a scientific basis for the antibacterial activity of REO. In addition, change on growth curve, conductivity and cell surface ultra-microstructure of the tested bacteria treated with REO were also studied to explore the antimicrobial mechanism. The results of DIZ,MIC ＆ MBC showed that REO was more sensitive to G＋ （Staphylococcus albus） and G- （Shigella dysenteriae） than G＋ （Bacillus subtilis） and G- （Escherichia coli）. The results of growth curve,membrane permeability and cell ultrastructure of tested bacteria showed that antibacterial mechanism may due to inhibition split speed of bacterial exponential phase and leading to the increase inpermeability of cell membranes.