固定化细胞发酵半纤维素水解液产木糖醇的研究  

PRODUCTION OF XYLITOL FROM HEMICELLULOSE HYDROLYSATE BY IMMOBILIZED CANDIDA TROPICALIS CELLS

作　　者：黄炜[1] 方祥年[1] 夏黎明[1] 

机构地区：[1]浙江大学化学工程与生物工程系,浙江杭州310027

出　　处：《林产化学与工业》2004年第1期29-33,共5页Chemistry and Industry of Forest Products

摘　　要：　固定在海藻酸钙凝胶中的热带假丝酵母(Candidatropicalis)细胞,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:32℃,每升氮源含酵母粉2.2g、胰蛋白胨3.7g,发酵液初始pH值6.0,分段改变摇床转速,其中0～24h为210r/min;24～72h为140r/min,固定化细胞凝胶珠与玉米芯半纤维素水解液体积比为1∶4。利用固定化细胞重复进行10批次共30d发酵,木糖醇得率平均为73.7%,达到了理论值的80%。固定化细胞密度高、抗逆性强、发酵性能稳定,水解液未经脱色与离子交换便可转化成木糖醇,显示了良好的应用前景。Candida tropicalis cells were immobilized in Ca-alginate beads and used for xylitol production from corn cob hydrolysates.Optimum batch fermentation conditions were as follows:32 ℃;per liter nitrogen contains 2.2 g (bacto-yeast) extract and 3.7 g bacto-tryptone;initial pH value 6.0;volume ratio between gel beads of immobilized cells and hydrolysates 1∶4;shaking speed was divided into two stages:210 r/min at 0-24 h,140 r/min at 24-72 h.In 10 repeated batches(30 days) fermentation,average xylitol yield was 73.7%.The immobilized cells have high density,steady fermentability and good resistance to inhibitors in the hydrolysates.Corn cob hydrolysates can be directly converted to xylitol without being decolored or ion-exchanged.This process can effectively reduce production costs,showing a broad prospects of applications.

关 键 词：木糖醇 固定化细胞 半纤维素水解液 发酵 热带假丝酵母 玉米芯 

分 类 号：TQ353.421[化学工程] TQ923[轻工技术与工程—发酵工程]