树干毕赤酵母在水解液中的驯化及木糖发酵

Pichia stipitis Adaptation and Xylose Fermentation in Hydrolysate Solution

通过在玉米秸秆蒸汽爆破水解液中的驯化,树干毕赤酵母(Pichia stipitis)能够在大量抑制物存在的情况下进行木糖发酵,且驯化后P.stipitis的木糖利用率为94.1%,乙醇得率为82.1%。在此基础上,对初始木糖质量浓度为30、45和60 g/L的水解液进行发酵,结果显示45 g/L初始木糖发酵的平均乙醇生成速率较高,且平均光密度(OD)增长速率较低。通过碳平衡计算和碳元素流向分析,51.6 g/L木糖水解液经过36 h发酵,碳回收率为89.7%,并且有48.5%的碳元素流向乙醇。

Through adapting in steam-exploded corn stalk hydrolysate, Pichia stipitis was capable of fermenting xylose to ethanol in presence of inhibitory components. The xylose consumption rate and the ethanol yield were 94.1% and 82.1%, respectively. Fermentation started at initial xylose concentrations of 30, 45 and 60 g/L. It was found that 45 g/L had a higher average ethanol productivity and a lower average biomass productivity. According to carbon balance and carbon metabolic effluence analysis, the carbon recovery was 89.7% , and 48.5% of carbon was converted to ethanol in the hydrolysate of 51.6 g/L xylose for 36 h.