玉米芯木糖-纤维素酶法分级工艺研究

[目的]对玉米芯木糖-纤维素酶法分级工艺中的稀酸预处理、蒸煮预处理和木聚糖酶解工艺进行优化。[方法]以干燥的玉米芯为原料,先进行稀酸-蒸煮预处理,研究不同因素对木糖得率的影响,然后再对物料进行木聚糖酶酶解。[结果]得到的玉米芯酸预处理优化工艺为:固液比1∶10 g/ml,H2SO40.5%,水浴70℃,处理2.0 h,木糖的损失率为4.72%,木糖酶解得率为30.03%。酸预处理后玉米芯残渣蒸煮预处理条件为:固液比1∶10 g/ml加入水,在120℃预水解2.0 h,蒸煮液木糖得率为54.77%,总酶解得率为69.11%。酶水解条件:pH 5.0,加酶量2 800 IU/g玉米芯,50℃水解36 h,总酶解得率83.41%。[结论]玉米芯蒸煮预处理能提高木糖的得率,单一用稀酸预处理再酶解得到木糖的得率并不理想。

Research on Xylose-Cellulose Enzymatic Hydrolysis Fractionation of Corncob

[Objective] The aim was to optimize the acidic pretreatment,steaming pretreatment and xylan enzymatic hydrolysis process of xylose-cellulose enzymatic hydrolysis fractionation.[Method] The dry corncob was firstly treated with diluted acid and then steamed to study the effect of different factors on the xylose yield,and finally hydrolyzed with xylanase.[Result] The acidic pretreatment conditions were 1∶10 g/ml of solid-liquid ratio,0.5% H2SO4,70 ℃ water bath and 2.0 h treatment time,under the conditions,the loss rate of xylose was 4.72% and the yield of xylose hydrolysis was 30.03%.The steaming pretreatment conditions were: 1∶10 g/ml of solid-liquid ratio,120 ℃ hydrolysis for 2.0 h,under the conditions,the yield of xylose was 54.77% and the total yield of hydrolysis was 69.11%.The enzymatic hydrolysis conditions were: 5.0 pH,2 800 IU/g xylanase amount and hydrolysis at 50 ℃ for 36 h,under the above conditions,the yield was 83.41%.[Conclusion] The steaming pretreatment of corncob improved the yield of xylose,and the yield of xylose from the hydrolysis directly after single acidic pretreatment was not ideal.