聚氨酯固定化热带假丝酵母发酵木糖醇.PDF

微生物学通报 JUL 20, 2009, 36(7): 943~948 Microbiology © 2009 by Institute of Microbiology, CAS tongbao@ 研究报告 聚氨酯固定化热带假丝酵母发酵木糖醇 * 王 乐 袁其朋 常 铮 范晓光 ( 100029) 摘 要: 固定在多孔聚氨酯载体中的热带假丝酵母(Candida tropicalis), 可有效地利用玉米芯半纤 维素水解液生产木糖醇。在摇瓶条件下, 采用分批发酵方式, 确立了适宜的发酵工艺参数为: 接种 量7%, 聚氨酯加入量 1.0 g/100 mL, 温度30°C, 初始pH 值6.0, 分段改变摇床转速进行溶氧调节, 其中0~24 h 为200 r/min; 24 h~46 h 为 140 r/min。聚氨酯固定化提高了菌体对发酵抑制物的耐受 力, 固定化细胞密度高, 发酵性能稳定, 发酵产率和体积生产速率都有所提高。水解液未经脱色与 离子交换便可转化成木糖醇, 大幅降低了成本, 显示了良好的应用前景。固定化细胞连续重复进 行 12 批次21 d 的发酵, 木糖醇得率平均为67.6%, 体积生产速率平均为 1.92 g/(L·h)。 关键词: 木糖醇, 半纤维素水解液, 聚氨酯, 固定化 Polyurethane Foam Immobilization of Candida tropicalis for Xylitol Production * WANG Le YUAN Qi-Peng CHANG Zheng FAN Xiao-Guang (State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China) Abstract: Immobilization conditions of Candida tropicalis to be absorbed in polyurethane foam carrier ma- terials were studied on the xylitol production from corn hemicellulosic hydrolysate. Optimum batch-fermentation conditions were as follows: inoculum amount, 7% (volume ratio); polyurethane foam quantity, 1.0 g/100 mL; 30°C; initial pH, 6.0. Shaking speed was divided into two-phase to accommodate the dissolved oxygen, with 200 r/min at 0~24 h and 150 r/min at 24 h~46 h. The immobilized