College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.
Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
J Ind Microbiol Biotechnol. 2019 Feb;46(2):203-208. doi: 10.1007/s10295-018-02128-4. Epub 2019 Jan 22.
Corynebacterium glutamicum is an important platform strain that is wildly used in industrial production of amino acids and various other biochemicals. However, due to good genomic stability, C. glutamicum is more difficult to engineer than genetically tractable hosts. Herein, a synthetic small regulatory RNA (sRNA)-based gene knockdown strategy was developed for C. glutamicum. The RNA chaperone Hfq from Escherichia coli and a rationally designed sRNA consisting of the E. coli MicC scaffold and a target binding site were proven to be indispensable for repressing green fluorescent protein expression in C. glutamicum. The synthetic sRNA system was applied to improve glutamate production through knockdown of pyk, ldhA, and odhA, resulting almost a threefold increase in glutamate titer and yield. Gene transcription and enzyme activity were down-regulated by up to 80%. The synthetic sRNA system developed holds promise to accelerate C. glutamicum metabolic engineering for producing valuable chemicals and fuels.
谷氨酸棒杆菌是一种重要的平台菌株,广泛用于氨基酸和各种其他生化物质的工业生产。然而,由于其基因组稳定性良好,谷氨酸棒杆菌比遗传上易于操作的宿主更难进行工程改造。在此,开发了一种基于合成小调控 RNA(sRNA)的基因敲低策略用于谷氨酸棒杆菌。来自大肠杆菌的 RNA 伴侣 Hfq 和一个由大肠杆菌 MicC 支架和靶标结合位点组成的合理设计的 sRNA 被证明对于抑制大肠杆菌中的绿色荧光蛋白表达是必不可少的。该合成 sRNA 系统被应用于通过敲低 pyk、ldhA 和 odhA 来提高谷氨酸的产量,导致谷氨酸滴度和产率几乎增加了三倍。基因转录和酶活性最高降低了 80%。所开发的合成 sRNA 系统有望加速生产有价值化学品和燃料的谷氨酸棒杆菌代谢工程。