Abstract: Hemicellulose, as one of the main compostions of lignocellulosic materials, leads to a complex structure characteristic, the presence of which hinders the access of enzyme to cellulose thus reduces efficiency of the hydrolysis.Different percentages of hemicellulose were removed from alkali-pretreated SCB since different concentrations of hemicellulase were added.Based on the results of compostitution analysis, SEM analysis, XRD analysis, as well as the enzymatic digestibility, it could be found that with the concentrations of hemicellulase added increasing, the content of lignin and crystallie index were larger and surface gap gradually deepened.Before the cellulase loading of 5FPU/g sustrate added, extra 1600U/g hemicellulase were used to treat the alkali-pretreated SCB which showed that the xylan and glucose conversion rate increasing 74.24% and 35.30%, respectively.It demonstrated that the removal of hemicellulose could effectively promote the enzymatic hydrolysis process, save the reaction time and increse the enzymatic conversion rate.

Key words: biomass, hemicellulase, enzymatic hydrolysis

摘要： 半纤维素作为木质纤维素的重要组分之一,通过氢键与纤维素的微纤丝结合,严重阻碍了纤维素表面与纤维素酶的接触,降低了酶解的效率。该试验以碱处理甘蔗渣作为底物,通过添加不同量的半纤维素酶去除不同比例的半纤维素。通过成分分析、X射线衍射(XRD)和扫描电镜(SEM)等手段分析添加半纤维素酶前后残渣的结构和酶解特性变化,发现随着半纤维素酶添加量的增大,残渣中木质素所占的比例逐渐增大,结晶指数逐渐增大,电镜表面沟壑逐渐加深,纤维束之间结构变得疏松。以半纤维素酶处理过的甘蔗渣作为底物,按照5FPU/g底物加入纤维素酶水解72h,与不添加半纤维素酶对照组相比,添加1600U/g半纤维素酶处理的试验组木聚糖的转化率提高了74.24%,葡聚糖转化率提高了35.30%。通过半纤维素酶添加可以有效促进纤维素酶解过程的进行,节约反应时间提高酶解转化率。

关键词: 生物质, 半纤维素酶, 酶解