Abstract: To evaluate the influence of remaining ionic liquid in fermentable sugars from lignocellulosic materials on subsequent ethanol fermentation,the toxicity of ionic liquid 1-ethyl-3-methylimidazolium acetate([Emim]Ac)to Saccharomyces cerevisiae AY93161 and its influence on ethanol fermentation process were investigated.After methylene blue staining,the morphological structure,budding and metabolic activity of Saccharomyces cerevisiae AY93161 at log growth phase in the presence of different concentrations of[Emim]Ac were observed under microscope-OLYMPUS CX41.The result showed that its single cell morphology changed when[Emim]Ac concentration was greater than 5 g·L^-1,and its reproduction rate by budding and its metabolic activity decreased with increasing[Emim]Ac concentration when[Emim]Ac concentration was greater than 0.1 g·L^-1.The half effective concentration(EC50)and the half inhibition concentration(IC50)of[Emim]Ac to Saccharomyces cerevisiae AY93161 were then measured by using solid and liquid suspension culture and their values were 4.45 and 7.70 g·L^-1 respectively.According to the parameters measured during the ethanol fermentation process at different[Emim]Ac concentrations,when[Emim]Ac in the medium was below 0.1 g·L^-1,there was almost no effect on the ethanol fermentation process,but when[Emim]Ac in the medium was greater than 0.1 g·L^-1,the ethanol fermentation was inhibited,resulting from its inhibitory effect on growth of the yeast Saccharomyces cerevisiae AY93161.

Key words: ionic liquid[Emim]Ac, toxicity, ethanol fermentation, Saccharomyces cerevisiae AY93161

摘要： 为了考察离子液体在由木质纤维原料制备可发酵糖中的残留对后续酒精发酵过程的影响,对离子液体1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)对酿酒酵母AY93161的毒性及其酒精发酵过程的影响进行研究。通过亚甲基蓝染色,利用OLYMPUS CX41显微镜观察不同[Emim]Ac浓度下对数生长期酵母细胞的形态结构,出芽情况及代谢活性,发现在[Emim]Ac浓度高于5 g·L^-1时,酵母细胞的形态结构会发生变化,在[Emim]Ac浓度高于0.1 g·L^-1时,随着[Emim]Ac浓度的增加,酵母的出芽速率及代谢活性降低。通过平板培养和液体悬浮培养测得[Emim]Ac对酵母的半有效浓度EC50和半抑制浓度IC50分别为4.45、7.70 g·L^-1。通过测定不同[Emim]Ac浓度下酵母酒精发酵的过程数据,发现在[Emim]Ac浓度低于0.1 g·L^-1时,对酵母酒精发酵过程几乎无影响,在[Emim]Ac浓度高于0.1 g·L^-1时,对酵母酒精发酵有抑制作用,[Emim]Ac对酵母酒精发酵的抑制作用主要是由其对菌体生长的抑制所致。

关键词: 离子液体[Emim]Ac, 毒性, 酒精发酵, 酿酒酵母AY93161