甲酸对酿酒酵母的细胞毒性

Cytotoxicity of Formic Acid to Saccharomyces cerevisiae

研究甲酸对酿酒酵母(Saccharomyces cerevisiae)GGSF16的毒害作用,测定不同质量浓度甲酸对酿酒酵母生长代谢的影响,结果表明,甲酸质量浓度为1.8 g/L时能够明显抑制酵母细胞的生长和降低乙醇产量,延长细胞发酵周期;酵母细胞外的核酸、蛋白质和丙二醛含量分别是对照组的1.4、1.67倍和5.3倍,胞内己糖激酶活力提高到3.95倍(P<0.05);从扫描电子显微镜结果可以看出酵母细胞经甲酸处理后光滑的表面出现了空洞、皱褶,细胞之间出现粘黏现象;傅里叶变换红外光谱分析结果表明甲酸通过改变蛋白质和糖类的结构破坏酵母细胞壁,同时增大了细胞膜通透性,使得细胞内容物外露,最终导致细胞的死亡。

To evaluate the toxic effect of formic acid on Saccharomyces cerevisiae GGSF16,the influence of fomic acid at different concentrations on the growth and metabolism of S.cerevisiae were determined.The results showed that formic acid at 1.8 g/L significantly inhibited the growth of yeast cells,reduced ethanol production,and extended cell fermentation cycle.The contents of extracellular nucleic acid,protein and malondialdehyde,and the activity of intracellular hexokinase in the treated cells were 1.4,1.67,5.3 and 3.95(P<0.05)times as high as those in the control group,respectively.Scanning electron microscopic(SEM)images showed that a large number of wrinkles and cavities appeared on the surface of intact and smooth yeast cells,and that and cell-cell adhesion was observed.Fourier transform infrared spectra demonstrated that formic acid could destroy the cell wall and increase the permeability of the cell membrane,thus leading to the leakage of cellular contents and cell death finally.