摘要
目的:以蒸汽爆破预处理后的玉米芯水提液为原料,利用驯化后的热带假丝酵母(Candidatropicalis)进行生物转化生产木糖醇。方法: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:发酵时间为48h,初始木糖量为150g/L,接种量为10%,温度30℃,初始pH值6.0,装液量50mL/250mL,采用三步转速调节溶氧,其中0～21h转速200r/min,21～28h转速170r/min,28～48h转速150r/min。结果:最终木糖醇得率可达到82.6%,体积生产速率为2.62g/(L.h)。结论:汽爆后的玉米芯木糖含量高,有害物质少,降低了发酵后期对酵母的抑制作用,利于木糖的转化和木糖醇的积累,大幅降低了发酵的成本,显示了良好的应用前景。
Objective： Utilizing corncobs after steam explosion and water extract as material to research on xylitol products by Candida tropicalis after domestication. This method can get high yields and good quality of products. Methods： Optimum batch-fermentation conditions were as follows ： time, 48 h ; initial xylose concentration, 150 g/L ; inoculum amount, 10 % （volume ratio） ; temperature, 30 ℃ ;initial pH, 6.0 ; liquid bulks, 50 mL/250 mL. Shaking speed was divided into threephase to accommodate the dissolved oxygen,with 200 r/min at 0;21 h,l？0 r/min at 21;28 h and 150 r/min at 28;48 h. Results： Final xylitol yield was 82.6 ; and xylitol volumetric productivity was 2.62 g/（L · h）. Conclusion： Steam explosion --pretreated corncob has high xylose content and less harmful substance. It reduces the restrain effect to Candida tropicalis on late fermentation period; meanwhile, it is beneficial to conversion of xylose and xylitol accumulation. This process can effectively reduce production costs, and it shows broad prospects of applications.
出处
《长治医学院学报》
2013年第2期85-89,共5页
Journal of Changzhi Medical College
基金
国家高技术研究发展计划(863)(2009AA02Z202)
关键词
木糖醇
热带假丝酵母
蒸汽爆破处理
玉米芯
发酵
Xylitol
Candida tropicalis
Steam explosion-pretreated
Corncob
Fermentation
