白酒糟水解液摇瓶发酵生产木糖醇的工艺优化

Process optimization for producing xylitol by shaking-flask fermentation from distiller's grains hydrolysates

为充分利用白酒糟资源,探讨酸水解液作为碳源发酵生产木糖醇的可行性。采用热带假丝酵母(Candidatropicalis1779)发酵酒糟水解液生产木糖醇,分别利用单因素试验和正交试验考察了影响发酵的工艺条件。发酵在250mL摇瓶发酵瓶中进行。结果表明,当种子龄27h、接种量20mL、装液量100mL、氮源添加量20mL、氮源浓度48g/L时发酵效果最好。该条件下发酵液中木糖醇浓度为11.85mg/mL,木糖利用率和还原糖利用率分别为45.62%和74.81%,残留木糖浓度为463.51μg/mL。发酵试验表明酒糟水解液作为碳源发酵生产木糖醇具有可行性。

Xylitol was produced from hydrolysates of distiller＇s grains by Candida tropicalis 1779, and the optimum conditions of the process were found by single-factor experiment and orthogonal test. The fermentations were conducted in 250 mL flasks. The results showed that the satisfied fermentation effect was attained under the technical conditions of inoculum age 27 h, inoculating volume 20mL, liquid volume in flask 100 mL, the addition of nitrogen source 20 mL and nitrogen concentration 48 g/L. Under these conditions, the concentration of xylitol and residual xylose were 11.85mg/mL and 463.51μg/mL in the fermentation broth, respectively. Under the optimum conditions, the utilization rate of xylose and reducing sugar are 45.62% and 74.81%, respectively. Fermentation experiments showed that it was feasible to produce xylitol by fermentation using lees hydrolysates as a carbon source.