无机盐预处理对棉秆酶水解的影响

The influence of inorganic salt pretreatment on cotton enzyme hydrolysis

利用无机盐对棉秆原料进行预处理,使部分木素和半纤维素溶出,从而提高酶水解效率。采用不同用量的硫酸、亚硫酸以及添加无机盐对棉秆进行预处理,分离固液相,测定木素脱除率、戊聚糖溶出率,将固相物质在50℃下进行酶水解,测定酶水解转化率;对实验过程中的葡萄糖、戊聚糖、木素进行物料衡算。结果表明:用硫酸对原料进行预处理时,添加亚硫酸氢钠能在原有的基础上,进一步提高木素的脱除率和酶水解的转化率;用亚硫酸对原料进行预处理时,添加氯化钠后,随着氯化钠添加量的增加,木素脱除率和酶水解转化率呈现下降的趋势;用氯化铁、氯化锌对原料进行预处理时,木素脱除率和酶水解转化率都很低。

The paper focused on the use of inorganic salts to pretreat raw materials, which can partly break up the protect structure of lignin and hemicelluloses. It can improve the conversion efifciency of enzymatic hydrolysis. Selecting different amount of sulfuric acid, sulphurous acid and inorganic salts to the pretreatment, separating the solid and spent liquor, determination the removal rate of lignin, the dissolution of pentosan. The substrate was enzymatic hydrolyzed under a settled condition, then calculating the conversion efifciency of enzymatic hydrolysis. All the glucose, pentosan and lignin were measured in the experiment to do calculation of material-balance. The experiment results show that the lignin removal rate, and the conversion rate of enzymatic hydrolysis were gradually increasing by adding NaHSO3 to the pretreatment when H2SO4 was used to pretreated the cotton stalk;when H2SO3 was used to pretreated the cotton stalk, the removal rate of lignin, and the conversion rate of enzymatic hydrolysis were gradually decreasing by adding NaCl to the pretreatment;when FeCl3 and ZnCl2 were used to pretreated the cotton stalk, both the removal rate of lignin, and the conversion rate of enzymatic hydrolysis were very low.