低共熔溶剂预处理提高甘草渣酶解效果优化

近年来，低共熔溶剂（deep eutectic solvent，DES）以易制备、成本低、易回收等优势，在生物质预处理方面受到广泛关注。本研究以氯化胆碱为氢键受体，乙醇胺为氢键供体，合成DES，研究了不同温度、时间和固液比预处理条件对中药渣组分和酶解效果的影响。结果表明：固液比1∶20、120℃、预处理4h后原料中木质素去除率达到78.42%，纤维素回收率为83.89%。随后对不同条件下所得底物进行酶水解，反应96h后发现，较优条件下所得底物酶解效率为78.57%，较未处理中药渣（30.40%）提高了1.58倍。类分形动力学分析表明，预处理温度对酶解效果影响最大。SEM、XRD和FTIR检测发现，预处理后底物形貌、结晶指数和官能团变化有利于酶解效果的提高。

Improving enzymatic hydrolysis effect of herb residue by deep eutectic solvent pretreatment

In recent years, deep eutectic solvent (DES) has attracted extensive attention in biomass pretreatment owing to its advantages of easy preparation, low cost and easy recovery. In this study, DES was synthesized with choline chloride as hydrogen bond receptor and ethanolamine as hydrogen bond donor. The effects of pretreatment conditions of different temperature, time and solid-liquid ratio on the components and enzymatic hydrolysis of herb residue were studied. The results showed that, the lignin removal rate was 78.42% and the cellulose recovery rate was 83.89% after pretreatment at 120℃ for 4 hours with the solid-liquid ratio of 1∶20. After 96 hours of enzymatic hydrolysis, it was found that the enzymatic hydrolysis efficiency of the substrate under the optimal conditions was 78.57%, which was 1.58 times higher than that of untreated herb residue(30.40%). Fractal like kinetic analysis showed that the pretreatment temperature had the greatest impact on the enzymatic hydrolysis effect. SEM, XRD and FTIR analysis showed that the changes of substrate morphology, crystallization index and functional group after pretreatment were conducive to the improvement of enzymatic hydrolysis effect.