PDF(Pubmed)
Abstract：
Reprogramming metabolic flux is a promising approach for constructing efficient microbial cell factories (MCFs) to produce chemicals. However, how to boost the transmission efficiency of metabolic flux is still challenging in complex metabolic pathways. In this study, metabolic flux is systematically reprogrammed by regulating flux size, flux direction, and flux rate to build an efficient MCF for chondroitin production. The ammoniation pool for UDP-GalNAc synthesis and the carbonization pool for UDP-GlcA synthesis are first enlarged to increase flux size for providing enough precursors for chondroitin biosynthesis. Then, the ammoniation pool and the carbonization pool are rematched using molecular valves to shift flux direction from cell growth to chondroitin biosynthesis. Next, the adaptability of polymerization pool with the ammoniation and carbonization pools is fine-tuned by dynamic and static valve-based adapters to accelerate flux rate for polymerizing UDP-GalNAc and UDP-GlcA to produce chondroitin. Finally, the engineered strain E. coli F51 is able to produce 9.2 g L-1 chondroitin in a 5-L bioreactor. This strategy shown here provides a systematical approach for regulating metabolic flux in complex metabolic pathways for efficient biosynthesis of chemicals.
摘要：
重编程代谢通量是构建有效的微生物细胞工厂（MCF）以生产化学物质的有前途的方法。然而,在复杂的代谢途径中，如何提高代谢通量的传输效率仍然具有挑战性。在这项研究中,代谢通量通过调节通量大小而系统地重新编程，通量方向,和通量率，为软骨素生产建立高效的MCF。首先扩大用于UDP-GalNAc合成的氨化池和用于UDP-GlcA合成的碳化池,以增加通量大小,为软骨素生物合成提供足够的前体。然后，氨化池和碳化池使用分子阀重新匹配，以将通量方向从细胞生长转移到软骨素生物合成。接下来,聚合池与氨化和碳化池的适应性通过基于动态和静态阀的适配器进行微调，以加速聚合UDP-GalNAc和UDP-GlcA以产生软骨素的通量速率。最后,工程菌株大肠杆菌F51能够在5-L生物反应器中生产9.2gL-1软骨素。此处显示的这种策略提供了一种用于调节复杂代谢途径中的代谢通量的系统方法，以实现化学物质的有效生物合成。
