酶解过程中木质素溶出规律及其与纤维素酶吸附域(CBM)的单分子作用

木质纤维原料中含有一定量的酸溶木质素，氧化预处理后含量会进一步增加。前期研究发现，这部分小分子酸溶木质素在酶解过程中将自动缓慢溶解至酶解液中，对酶解有促进作用。本项目拟通过改变氧化预处理方法和条件，调控处理后的木质纤维原料中酸溶木质素含量、分子量大小及分布以及活性官能团含量，进而研究酶解过程中可溶木质素的释放规律及其与酶解效率的相关性，建立可溶木质素的结构性质与酶解糖化率的构效关系。此外，以氧化预处理后残留在样品中的酸溶木质素为主要研究对象，利用原子力显微镜的形貌和识别成像技术，结合单分子动态力谱分析，从单分子水平研究酸溶木质素与纤维素酶的吸附域之间相互作用力大小及性质。进而通过原子力显微镜识别成像功能实时原位监测可溶木质素与纤维素酶结合后在木质纤维原料上的吸附和水解行为，揭示可溶木质素促进酶解的机制。研究结果将为木质纤维原料预处理方法和工艺的选择以及酶解技术的改进提供理论指导。

Lignocellulose biomass contains a certain amount of acid-soluble lignin, and the content will be further increased after oxidative pretreatment. Previous studies have found that acid-soluble lignin dissolve into the enzymatic hydrolysate slowly during the enzymatic hydrolysis process, which can promote the enzymatic hydrolysis. This project will regulate the content, molecular weight and distribution of acid-soluble lignin in the pretreated lignocellulose biomass by changing the oxidative pretreatment methods and conditions, and the objective is to establish the relationship between the structure and properties of soluble lignin and the enzymatic efficiency. In addition, the interaction between the acid-soluble lignin and carbohydrate binding module (CBM) will be investigated based on a single molecular level by using atomic force microscopy topography and recognition imaging technology (TREC) combined with single molecular dynamic force spectrum analysis. At the same time, the adsorption and hydrolysis behavior of the “soluble lignin-cellulase complex” on the lignocellulose will be monitored by AFM. The results will provide theoretical guidence for the design of pretreatment methods and processes of lignocellulose biomass and the improvement of enzymatic hydrolysis.