ACA微囊化酵母细胞利用酒糟水解液发酵木糖醇的初步研究

Primary Study on Xylitol Production of Wine Lees Hydrolysate by Microencapsulated Candida tropicalis Cells

通过ACA(Chitosan-alginate)微胶囊技术包埋的热带假丝酵母(Candidatropicalis)细胞能有效地发酵酒糟(文中均指丢糟)半纤维素水解液生产木糖醇。在摇瓶条件下,适宜的工艺条件为:初始木糖质量浓度100g/L,发酵液初始pH值6.0,限制性供氧,分段改变摇床转速(0～24h为180r/min,24～48h为120r/min)使菌株在培养早期获得较高水平的通气率,而后降低菌株的呼吸率。每升氮源含酵母膏1.8g,蛋白胨3.0g,微囊化胶珠与水解液体积比为1∶4。此方法有望大幅降低原料预处理的成本,发酵结果良好,显示了良好的应用潜力。

Candida tropicalis cells were immobilized in Chitosan-alginate beads and used for xylitol production from wine lees hydrolysate. The optimum xylitol fermentation conditions were studied. The results showed that initial xylose concentration of hydrolysate was 100g/L, initial pH value was about 6.0. Shaking speed used during 0-24 hours was 180r/min and was 120r/min for the 24th-48th hours to acquire higher level of aeration rate at the earlier phase of cultivation and then to decrease the level of respiration of the micro-organism. Each liter of nitrogen contains 1.8g bacto-yeast exact and 3.0g bacto-tryptone. Volume ratio of gel beads immobilized cell to hydrolysate was 1：4. The process can effectively reduce the pretreatment costs. The fermentation results are desirable and show abroad potential of applications.