【摘要】 实验采用以15.0 g/L木糖和30.0 g/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1.5 L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100~150 mL/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60 mL/h时,二级连续发酵液中酒精平均质量浓度为13.79 g/L,还原糖利用率83.09%;当底物流加速度约为45 mL/h时,发酵液酒精质量浓度平均值为15.41 g/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35 d的运行中从未发现"染菌"现象,发酵操作相当稳定。更多还原

【Abstract】 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 temperature 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.更多还原