乙醇发酵菌种的选育及发酵条件的初步探索试验

Strain Screening of Hydrolysate Fermentation for Ethanol and Preliminary Study on Fermentation

对5种燃料乙醇发酵菌种进行了选择,对较好菌种做了耐高温驯化及发酵条件的优化。结果表明,在以葡萄糖为单一碳源的发酵中,相对于休哈塔假丝酵母、嗜单宁管囊酵母、间型脉胞菌、好食脉孢菌,酿酒酵母种液制备时间最短（对数生长期在6~13 h）,发酵制取乙醇得率最高;对酿酒酵母驯化后,得到一株可在42℃正常生长的菌株;经研究,该耐高温菌株的较优发酵条件为温度30℃、转速150 r/min、初始pH值5.0、接种量10%。该耐高温驯化后的酿酒酵母不能直接用于水解液发酵制乙醇,还需要经过驯化或菌种改良后方能使用。

Strains were selected from five fuel ethanol hydrolysate fermentation.Thermostable domestication and the fermentation optimization of better strain were studied.The results showed that in the fermentation comparison of Candida shechatae,Pachysolen tannophilus,Neurospora intermedia and Neurospora sitophila with glucose as the single carbon source,Saccharomyces cerevisiae was the best for the highest ethanol yield and the shortest log phase with 6-13 h.By domestication,a thermostable strain was screened out,which performed normal growth under 42 ℃.By optimizing,the optimum fermentation conditions were determined for temperature 30 ℃,stirring rate 150 r/min,initial pH value 5.0,inoculation amount 10 %.The yeast can not be directly used for ethanol fermentation hydrolysis.But it can be used after domesticated or strain improvement.