Helal G A, Sarhan M M, Abu Shahla A N K, Abou El-Khair E K
Botany Department, Faculty of Science, Zagazig University, Sharkia Governorate, Egypt.
J Basic Microbiol. 2006;46(5):375-86. doi: 10.1002/jobm.200510084.
The growth of Saccharomyces cerevisiae was completely inhibited using 2.0 microl/ml or 4.0 microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Sabouraud's broth medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 3.0 microl/ml inhibited about 98% of yeast growth after 24 hr of incubation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) showed morphogenic and ultrastructure changes in the fumigated cells with 1.0 microl/ml of the oil. These changes including decrease in cell size, depressions on the surface of the cells, alteration in cell wall thickness and disruption of plasma membrane. Moreover, Ca(+2), K(+) and Mg(+2) leakages increased from the fumigated cells and its total lipid content decreased. Also, the fatty acid composition was altered with decrease in the amount of saturated fatty acids and increase in the amount of unsaturated fatty acids.
在沙氏肉汤培养基中，分别采用熏蒸法或接触法施加2.0微升/毫升或4.0微升/毫升的柠檬香茅精油，酿酒酵母的生长被完全抑制。还发现该精油在相同浓度下具有杀真菌作用。与对照相比，1.0微升/毫升和3.0微升/毫升的亚致死剂量在孵育24小时后抑制了约98%的酵母生长。使用光学显微镜（LM）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）进行的显微镜观察显示，用1.0微升/毫升的精油熏蒸处理的细胞出现形态发生和超微结构变化。这些变化包括细胞大小减小、细胞表面凹陷、细胞壁厚度改变以及质膜破裂。此外，熏蒸处理的细胞中Ca(+2)、K(+)和Mg(+2)的泄漏增加，其总脂质含量降低。而且，脂肪酸组成发生改变，饱和脂肪酸含量减少，不饱和脂肪酸含量增加。
