基因重组酵母发酵木糖产酒精的研究

Ethanol Fermentation on Xylose by a Recombinant Yeast

以一株基因重组酵母为研究对象,探讨了厌氧条件下pH值、底物浓度、接种量、乙酸质量分数和葡萄糖添加量等关键因子对木糖发酵的影响。结果表明,重组酵母Saccharomyces cerevisiae ZU-10有较强的发酵木糖产乙醇的能力,在80g/L(相对木糖)、初始pH值5.5、接种量1.2g/L(细胞干质量,相对培养液)、30℃下发酵72h,发酵液中乙醇质量浓度达到28.9g/L。发酵液中的乙酸质量分数低于0.05%时对发酵木糖影响不大。添加适量的葡萄糖可促进木糖发酵,在30g/L木糖培养液中添加40g/L葡萄糖,36h内木糖利用率从79.0%增加到85.7%。

The key affecting factors of enthanol fermentation on xylose by a recombinant yeast of Saccharomyces cerevisiae ZU-10 were investigated. Fermentation was performed with 80 g/L xylose and inoculum of 1.2 g/L（ cell dry weight） at initial pH value 5.5, 30 ℃ under anaerobic condition, and 28.9 g/L ethanol was obtained within 72 h. Acetic acid of mass fraction lower than 0.05 % in culture medium caused minor influence on xylose fermentation. Addition of glucose to culture medium favored fermentation of xylose, and 85.7 % xylose was utilized within 36 h at 40 g/L glucose in culture medium containing 30 g/L xylose.