摘要
为促进超高浓度乙醇发酵(350 g/L起始葡萄糖),采用均匀设计法优化发酵培养基成分,结果为8.2 mmol/L Mg2+,1.0 mmol/L Ca2+,30.0 g/L蛋白胨和27.1 g/L酵母浸出膏。采用该优化培养基,实验测得发酵终点乙醇体积分数为18.3%,比未优化时提高约58%,同时,菌体生长和葡萄糖转化利用等其它参数也明显提高。实验进一步探索与发酵状况改善有关的酵母生理方面的变化。结果表明,在发酵过程中生长于优化培养基的菌体的质膜ATP酶活力和胞内海藻糖含量明显高于对照组,提示二者在促进发酵中的重要作用。这是超高浓度乙醇发酵培养基优化引起酵母质膜ATP酶活力和胞内海藻糖含量变化的首次报道。
To enhance very high gravity(VHG)ethanol fermentation,the uniform design approach was employed to optimize a fermentation medium.An optimal mixture based on 350 g/L initial glucose was determined to be 8.2 mmol /L Mg2+,1.0 mmol /L Ca2+,30.0 g /L peptone and 27.1 g /L yeast extract.With this medium,18.3 % of final ethanol in fermentation broth was obtained,representing approximately 58% increase as compared with 11.6% obtained by using non-optimized medium.Medium optimization also resulted in other significant improvements,such as cell growth and glucose utilization.Experiments were further performed to understand the yeast physiological aspects possibly associated with the fermentation improvement.The results showed that compared to the control cells grown in non-optimized medium,the cells grown in optimal medium always exhibited substantially higher plasma membrane ATPase activity and accumulated much more intracellular trehalose during the fermentation process,suggesting that both plasma membrane ATPase and intracellular trehalose played an important role in improving fermentation.This is the first report concerning the increased yeast plasma membrane ATPase activity and trehalose accumulation prompted by medium optimization during VHG fermentation.
出处
《化工进展》
EI
CAS
CSCD
北大核心
2010年第S2期300-304,共5页
Chemical Industry and Engineering Progress
基金
福建省自然科学基金项目(E0810018)
华侨大学高层次人才科研基金项目(05BS306)资助
