桉木碱性亚硫酸盐预处理对酶解糖化效果的影响

Effect of Alkaline Sulfite Pretreatment on Enzymatic Saccharification of Eucalyptus

用碱性亚硫酸盐对桉木原料进行预处理,并通过傅立叶红外光谱、扫描电镜、X射线衍射等手段对预处理所得样品进行分析.结果表明:桉木原料经碱性亚硫酸盐预处理后,有部分木质素和少量半纤维素被水解;纤维素的相对结晶度下降14.34%;碳水化合物的结构变得松散,纹孔膜破裂,纤维碎片增多,极大地提高了后续纤维素酶的可及度.进一步的酶解实验表明:桉木经预处理后,酶解液中的木糖、葡萄糖量分别占桉木原料中木糖、葡萄糖量的67.33%和88.11%,得率比未经预处理直接酶解时提高了7.51倍和4.33倍;桉木原料中52.39%的木质素可在酶解残渣中得到回用.

Alkaline sulfite was used to pretreat eucalyptus lignocellulose,and the product was investigated by means of FT-IR,SEM and XRD.The results show that,after the pretreatment,some lignin and hemicellulose hydrolyze,the relative crystallinity of cellulose decreases by 14.34%,the carbohydrate in eucalyptus becomes incompact,the pit membrane breaks and more fiber fragments form,thus greatly improving the accessibility of the cellulase in the later treatment.Moreover,it is found from the further enzymatic hydrolysis that,after the pretreatment,the mass of xylose and glucose amounts respectively to 67.33% and 88.11% of that of the raw eucalyptus,that the corresponding yields are respectively 7.51 and 4.33 times higher than those without pretreatment,and that 52.39% of lignin in the raw eucalyptus can be reused from the enzyme solution scraps.