天津科技大学学报2025，Vol.40Issue(2)：13-21,9.DOI:10.13364/j.issn.1672-6510.20240009
产L-异亮氨酸谷氨酸棒杆菌的代谢工程构建
Construction of Metabolic Engineering of Corynebacterium glutamicum for Producing L-Isoleucine
摘要
Abstract
L-isoleucine,as an essential amino acid,possesses distinctive physiological functions and has been widely used in food,pharmaceutical and agricultural industry.However,the current Corynebacterium glutamicum strains used for scaled-up production of L-isoleucine exhibit auxotrophy and the fermentation period is relatively long.In this study,an L-isoleucine producing strain was developed with the use of metabolic engineering strategies.Initially,the feedback resistant aspartate kinase,threonine dehydratase and acetolactate synthase encoding genes lysCA279T,ilvAG418A/T1147G and ilvBNA139T/T140A were overexpressed to enhance the L-isoleucine synthetic pathway.As a result,3.5 g/L of L-isoleucine was produced by the gener-ated strain ILE-3.Then,the pyruvate carboxylase encoding gene pyc was overexpressed to improve L-aspartate supply.Fi-nally,brnFE was overexpressed to promote the efflux of L-isoleucine.After fermentation for 48 h in a 5 L fermentor,the L-isoleucine production titer and yield achieved 21.3 g/L and 14.1%by the final strain ILE-6.The strain ILE-6 possesses clear genetic background,non-auxotroph and short fermentation period.The strategies applied in the study thus could provide reference for metabolic engineering strains for producing branched chain amino acids.关键词
L-异亮氨酸/L-苏氨酸/代谢工程/谷氨酸棒杆菌/代谢流Key words
L-isoleucine/L-threonine/metabolic engineering/Corynebacterium glutamicum/metabolic flux分类
生物科学引用本文复制引用
张佳蓉,李彦臻,芦楠,张成林..产L-异亮氨酸谷氨酸棒杆菌的代谢工程构建[J].天津科技大学学报,2025,40(2):13-21,9.基金项目
国家自然科学基金项目(31770053) （31770053）
天津市研究生科研创新项目(2022BKYZ006,2022BKYZ018) （2022BKYZ006,2022BKYZ018）
