威兰胶因具有良好的热稳定性、增稠性等性能，可应用于食品、石油等诸多领域。但是，发酵产量较低是制约其大规模应用的瓶颈问题。因此，本项目拟通过建立代谢酶空间组织工程的方法，大幅度提高威兰胶生产水平，推进其工业应用。主要研究内容包括：（1）设计并合成DNA支架和可特异性识别DNA支架上不同靶序列的类转录激活因子效应物TALEs，验证TALE-DNA支架的有效性；（2）将威兰胶合成途径中的关键酶UgpG和WelB分别与TALEs融合表达，借助TALEs与DNA特异性结合形成的支架结构，将关键酶进行组装，构建多酶复合体，模拟底物沟道传递与加工机制，提高酶的催化效率，实现威兰胶产量的大幅提高；（3）利用转录组和代谢组学方法，探索多酶复合体优化细胞代谢路径的分子机制。通过本项目的实施，建立细菌代谢酶空间组织工程方法，并推动该方法在代谢工程中的普遍应用，为建立具有良好普适性的微生物代谢工程新理论奠定基础。

Welan gum has great potential to be widely applied in food, petroleum and other industries as a stabilizing, thickening, emulsifying agent because of its excellent rheological properties. Low fermentation yield is a bottleneck restricting its large-scale application. This project will enhance the welan gum production through the spatial organization engineering method of metabolic enzymes. The main research contents are as follows: (1) Artificial DNA scaffolds and transcription activator-like effectors (TALEs) specifically binding with different sequences in DNA scaffolds will be designed and synthesized. Furthermore, the effectiveness of the TALE-DNA scaffold will be verified. (2) Two key enzymes in the biosynthetic pathway of welan gum will be expressed fused with TALEs and their synthetic multi-enzyme complexes will be constructed with the help of specific interaction between TALEs and DNA scaffold. The multi-enzyme complexes will be expressed in the strain Sphingomonas sp. WG to obtain strains with high welan gum productivity. This work will develop spatial organization engineering method of metabolic enzymes based on the substrate channeling, to improve the catalytic efficiency of enzymes at low expression level and realize the enhancement of welan gum production. (3) The transcriptomes and metabolomes of different strains will be analyzed to reveal the mechanism of multi-enzyme complexes to enhance the welan gum production. It will promote the universal application of the spatial organization engineering method of metabolic enzymes and provide the basis for the establishment of a new theory of microbial metabolic engineering.