摘要
休哈塔假丝酵母(Candida shehatae)的改良菌种R能同时将半纤维素中的戊糖和己糖发酵成乙醇。当酵母细胞浓度高于8g/L和木糖含量高于总糖的20％时,较易代谢的己糖对木糖所产生的抑制作用可被消除。在30℃～40℃和限制供氧的条件下,90％以上的单糖得到了利用,乙醇得率为0.43～0.48g/g消耗的糖。厌氧发酵导致木糖的不完全利用和木糖醇的积累,而供氧过量则导致酵母细胞增殖并降低乙醇得率。该菌种对半纤维素水解液(如亚硫酸盐制浆废液、玉米秆水解液和落叶松浸提液)中的发酵抑制物有较高的忍耐能力,有重要的工业应用前景。
Improved R strain of Candida shehatae was able to ferment both pentoses and hexoses derived from hemicellulose simultaneously. Large inoculum(8 g/L or higher)and high xylose concentration (20% of total sugar or higher) eliminated the catabolite repression caused by more-favored hexoses. More than 90% of sugar was utilized and 0. 43-0.48g ethanol/g consumed sugar was produced at 30-40℃ with limited oxygen supply. Anaerobic fermentation resulted in incomplete xylose utilization and xylitol accumulation, while aerobic process produced cell biomass at the expense of ethanol yield. This strain could tolerate high concentrations of fermentation inhibitors present in hemicellulosic hydrolysates such as spent sulfite liquor, corn stover hydrolysate and larch extract,and is of great potential for industrial applications.
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
1991年第1期17-24,共8页
Chemistry and Industry of Forest Products
基金
国家教委优秀年轻教师基金资助项目
关键词
半纤维素
酵母
木糖
乙醇
成糖
Fermentation
Xylose
Ethanol
Hemicellulose
