麦草酸水解及水解液木糖发酵的研究

Study on Acid Hydrolysis of Wheat Straw and Fermentation of Xylose in Hydrolysate to Xylitol

采用甲酸/盐酸水解体系水解麦草,发现65℃水解0.5 h可实现麦草中半纤维素的充分水解。选用热带假丝酵母发酵麦草甲酸水解液制取木糖醇。分别研究了在不同浓度甲酸及甲酸根条件下D-木糖的发酵效果,发现在2 g/L的甲酸及5 g/L的甲酸根条件下,D-木糖实现发酵并得到最大产率的木糖醇,高浓度的甲酸及甲酸根都会抑制D-木糖的发酵。采用D311型阴离子交换树脂脱除甲酸根,实现了麦草水解液的发酵,木糖醇最高得率为16.88%(木糖醇/木糖)。

Hemicellulose could be hydrolyzed adequately when wheat straw was retained in the system of formic acid/hydrochloric acid for 0.5 h under 65 ℃. Straw hydrolysate was fermented by Candida tropicalis to produce xylitol. The effects of different concentration of formic acid and formate on the fermentation of D-xylose were studied, D-xylose could be fermented to produce xylitol availably with a concentration of 2 g/L formic acid or 5 g/L formate, A high concentration of formic acid or formate restrained the fermentation of D-xylose. Straw formic acid hydrolysate could be fermented to produce xylitol after the formate was removed by ion exchange resins of D311. All xylose was consumed within 72 h with a xylitol yield of 16.88 % （xylitol/xylose）.