代谢工程改造谷氨酸棒状杆菌促进L-异亮氨酸发酵合成的研究进展

L-异亮氨酸作为必需氨基酸具有多种生理功能，对人体和动物健康有重要的调节作用。微生物发酵是工业生产L-异亮氨酸的主要方式，而谷氨酸棒状杆菌（Corynebacterium glutamicum）是L-异亮氨酸发酵生产的主要菌株，主要通过筛选和随机诱变得到，其遗传背景不明且很难通过诱变进一步提高产量，因而通过代谢工程改造谷氨酸棒状杆菌生产L-异亮氨酸成为近年来研究热点。该文综述了近年来代谢工程改造谷氨酸棒杆菌促进L-异亮氨酸生物合成的相关研究，主要涉及代谢通量调控、解除反馈抑制、强化还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）水平以及提高产物分泌能力等方面，对进一步改造菌株和促进L-异亮氨酸发酵合成具有一定的参考意义。

Advances in of modifying Corynebacterium glutamicum to promote L-isoleucine fermentation synthesis by metabolic engineering

As an essential amino acid, L-isoleucine possesses a variety of physiological functions and plays an important role in regulating human and animal health. Microbial fermentation is the main method for L-isoleucine production, and Corynebacterium glutamicum has been the cardinal strain for L-isoleucine fermentation production, which is obtained by screening and random mutagenesis. Due to its unclear genetic background and great difficulty for enhancing L-isoleucine yield via mutagenesis, metabolic engineering has been primary means to modify C. glutamicum for L-isoleucine production which draws increasing attentions. Recent studies on modifying C. glutamicum to promote L-isoleucine biosynthesis by metabolic engineering were reviewed in this article, mainly involving the metabolic flux regulation, removing feedback inhibition, enhancing nicotinamide adenine dinucleotide phosphate (NADPH) level and improving product secretion ability, which could provide significance reference for further modifying strains and promoting L-isoleucine fermentation synthesis.