中文摘要：

实验采用以15．0g／L木糖和30．0g／L葡萄糖混合物，来模拟植物纤维原料水解液作为发酵底物，在工作体积约为1．5L的两个串联的全混釜生物反应器中，控制发酵温度35℃，通风量100～150mL／min，进行了树干毕赤酵母二级连续发酵的研究；在此基础上，采用固定化和低pH值处理技术对连续发酵作了进一步研究。结果表明，当底物流加速度约为60mL／h时，二级连续发酵液中酒精平均质量浓度为13．79g/L，还原糖利用率83．09％；当底物流加速度约为45mL／h时，发酵液酒精质量浓度平均值为15．41g/L，还原糖利用率为90．38％；当采用固定化技术和低pH值处理技术后，该系统在连续发酵35d的运行中从未发现“染菌”现象，发酵操作相当稳定。

英文摘要：

Study on continuous fermentation of xylose/glucose mixture by Pichia stipitis under oxygen-limited condition to prepare ethanol was carried out. Mixture of 15.0 g/L xylose and 30.0 g/L glucose as substitute of lignocellulosic hydrolyzate, was used as main fermentation substrate. Tow-stage fermentation cultures were carried out in a two-reactor system under condition of tem- perature of 35 ℃ and a ventilation rate of 100-150 mL/min. The working volume of single reactor was 1.5 L. When the influent rate was ca. 60 mL/h, average ethanol concentration in the effluent was 13.79 g/L, and the utilization rate of reducing sugar was 83.09 %. When the influent rate was changed to ca. 45 mL/h average ethanol concentration in the effluent was 15.41 g/L, and the utilization rate of reducing-sugar was 90.38 %. Using immobilization and low pH value treatment method, the system was run steadily and no contamination was found during a 35-day research.