发酵玉米芯酶水解液生产木糖醇的研究

Studies on Xylitol Fermentation of Corncobs Enzymatic Hydrolysate

假丝酵母(Candida sp.)菌株经驯化后显著地提高了对水解液中发酵抑制物质的耐受力,从而增加了木糖利用率和木糖醇得率。玉米芯经酶水解得到水解液,在30℃下采用假丝酵母菌株直接发酵生产木糖醇。对发酵条件进行了优化,优化结果为:接种量5%(体积比),种子龄20 h,氮源组成:2.5 g/L的酵母浸膏,2.5 g/L的胰蛋白胨,250 mL三角瓶装液100 mL,初始pH值6。在此条件下,木糖醇得率达65%。该方法大大降低了预处理的成本,显示了良好的应用前景。

Corn cobs hydrolysate produced by enzymatic hydrolysate pretreatment can be directly fermented using the adapted yeast strain at 30℃. The optimum fermentation conditions were as follows： inoculum rate 5%（volume ratio）, inoculum age 20 h, nitrogen source 2.5 g/L Bacto-yeast extract and 2.5 g/L Bacto-tryptone, volume charge 100 mL in 250 mL flasks, intitial pH value 6. Both of xylose utilization efficiency and xylitol yield were higher 65% respectively. This process can effectively reduce the pretreatment of costs, showing broad prospects of applications.