木质素糖基化改性过程动力学解析及过程强化

酚羟基赋予了木质素降低溶液表面张力、抗氧化、抗菌和吸附重金属等多种功能，但木质素结构高度聚合、亲水性差，导致其酚羟基活性偏弱，限制了木质素的高值化应用。采用木质素过氧化物酶，在催化硫酸盐木质素与阿魏酸氧化聚合过程中引入大量亲水性糖基，可以实现木质素的糖基化亲水改性和酚羟基的活化。为掌握改性过程动力学规律，项目提出研究木质素过氧化物酶催化机理，建立改性过程动力学模型；根据动力学参数，确定糖基化改性过程中的速率限制因素，并研究过程强化手段。研究从反应机理出发，通过动力学解析，致力于揭示酶促反应在多因素影响下的反应规律，为复杂体系中酶促反应的动力学研究提供理论支持；同时，研究提出了新型的木质素酶法改性工艺，通过揭示糖基化对木质素中酚羟基活性的影响规律，可为木质素功能性强化研究提供理论依据和研究基础。

Phenolic hydroxyl groups provides the capability of lignin being used as surfactant, antioxidant, antibacterial agent, and heavy metal adsorbent. However, due to the highly polymerized structure of lignin with hydrophobic functional groups in dominant, lignin exhibits poor hydrophilicity with limited the activity of its phenolic hydroxyl groups, which constrains its effectiveness as functional materials. To improve the activity of phenolic hydroxyl groups, we proposed the synthesis of “hydrophilic lignin materials” through the glycosylation of Kraft lignin under the catalysis of lignin peroxidase, which is capable of introducing glycosyl groups to the lignin structure during lignin-ferulic acid polymerization. Combining the characteristics of lignin peroxidase, the mechanistic based kinetics of the lignin glycosylation process will be given. Reaction optimization will be conducted based on the rate limiting steps determined by the kinetics parameters. We proposed the study of surfactant, solvent system, and Lewis acid on the impact of the glycosylation process. This project focuses on revealing the properties of a complex enzymatic reaction through kinetics study. Meanwhile, a novel enzyme-based lignin modification method is proposed and the impact of glycosyl groups on the functionalization of phenolic hydroxyl groups will be studied to reveal the functionalization mechanisms with robust theoretical supports.