Xylitol Production by Immobilized Yeast Cell Using Enzymatic Hydrolysate of Corncob

The corncob auto-hydrolysate was hydrolyzed by xylanase to obtain the fermentable xylose solution.Its hydrolysis rate was faster and yield of xylose was higher than the direct hydrolyzing corncob by xylanase.Although the fermentability of the enzymatic hydrolysate by yeast was not as good as pure xylose solution,it was much better than the acid hydrolysate of corncob.In making alginate/chitosan(ACA) microcapsules,the optimal reaction time and liquefying time was 18 and 20 min respectively.The microcapsules should be used at pH 3～6.The immobilized cells by ACA microcapsules were used to produce xylitol using enzymatic hydrolysate in repeated batch cultures.The average yield of xylitol reached 61.4% in 8 batches.