生物—碱氧化预处理玉米秸秆酶解条件的优化

Optimization of enzymatic hydrolysis of corn straw after biological-alkaline/oxidative pretreatment

白腐菌生物—碱氧化预处理(BAO预处理)具有环境友好、低能耗的优势,是一项很有前景的生产纤维质乙醇预处理技术。为获得预处理后玉米秸秆的最优酶解条件,通过动力学研究评价了纤维素酶负荷、反应时间、基质浓度对还原糖产量的影响,并利用响应面分析法优化了酶解反应温度、pH值和转速。结果表明,最适的酶解糖化条件为:酶负荷30FPU/g,基质浓度20g/L,反应时间48h,pH4.8,转速200r/min,反应温度49℃。在此条件下,秸秆的还原糖产量达到(0.479±0.012)g/g。

Biological-alkaline/oxidative pretreatment（BAO pretreatment）with white rot fungi is a promising technology for cellulosic ethanol production because of the advantages of mild environmental conditions and low energy consumption. In order to obtain the optimal conditions for enzymatic hydrolysis of corn straw treated by BAO pretreatment, the effects of cellulase loading, reaction time and substrate concentration on reducing sugar yields were evaluated by dynamics study, and the reaction temperature, rotational speed and pH value of enzymatic hydrolysis were also optimized by response surface design. The results indicated that 30 FPU/g of cellulase loading, 20 g/L of substrate concentration, 49℃ of reaction temperature, 200 r/min of rotational speed and pH 4.8 for 48 hours could be the most effective and economical way of enzymatic hydrolysis. Under such conditions, the reducing sugar yield reached （0.479±0.012）g/g .