木糖和纤维二糖共利用木葡糖醋杆菌的构建与调控研究

以木质纤维素为底物，通过生物炼制生产生物基产品对社会经济的绿色可持续发展具有重要意义。但多数传统生产菌株仅可利用木质纤维素水解产物中的葡萄糖，缺乏高效木糖代谢途径，严重制约了其经济性。细菌纤维素(Bacterial Cellulose, BC)具备高纯度、高生物相容性等特性，在医学材料领域具有重要应用价值。本申请针对木质纤维素五六碳糖共利用及多糖类化合物生产中菌株生长与生产平衡的关键科学问题，以BC生产菌株木葡糖醋杆菌为出发菌株，通过合成生物学方法寻找和构建木糖和纤维二糖代谢途径，实现复合碳源高效共利用。进一步，本申请拟通过构建代谢网络模型，解析共利用菌株的代谢网络变化规律并调控关键代谢节点，以实现菌株生长与生产平衡，提高代谢通路原子经济性。本申请通过木葡糖醋杆菌中木糖和纤维二糖共利用代谢途径的构建和代谢网络变化规律解析，可为高效利用木质纤维素资源生产多糖类生物基产品提供新的思路与借鉴。

Biorefinery, which uses lignocellulose as substrate to produce bio-based products, is of great significance to the development of green and sustainable economy. However, most traditional production strains can only utilize the glucose in the lignocellulose hydrolysate, and lack efficient xylose metabolism pathways, which severely restricts its economic efficiency. Bacterial cellulose (BC) has characteristics of high purity and high biocompatibility, and has important applications in medical materials field. This application, which aims at the critical scientific problems of the co-utilization of glucose and xylose in lignocellulose hydrolysate and the balance between growth and production of strains in the production of polysaccharide compounds, uses the BC production strain Komagataeibacter xylinus as the starting strain. To achieve the co-utilization of carbon sources, this application plans to explore and construct xylose and cellobiose metabolic pathways in Komagataeibacter xylinus through synthetic biology methods. Furthermore, this application plans to construct a metabolic network model to analyze the change rules of the metabolic network, and next to regulate the critical metabolic nodes to balance the growth and production of strains and improve the atomic economy of metabolic pathways. This application explores the xylose and cellobiose metabolic pathway construction and metabolic network change rules in Komagataeibacter xylinus, which can provide new ideas and examples for the efficient use of lignocellulose resources to produce bio-based polysaccharide products.