Metabolic engineering of Corynebacterium glutamicum by synthetic small regulatory RNAs
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.
KeywordsCorynebacterium glutamicum Gene knockdown Glutamate Hfq Synthetic sRNA
This work was funded by the National Natural Science Foundation of China (31700044 and 31870044), the Key Research Program of Chinese Academy of Sciences (ZDRW-ZS-2016-2), the International Partnership Program of Chinese Academy of Sciences (153D31KYSB20170121), the Tianjin Municipal Science and Technology Commission (15PTCYSY00020) and the first Special Support Plan for Talents Development and High-level Innovation and Entrepreneurship Team of the Tianjin Municipal City.
All data generated or analysed during this study are included in this published article and its supplementary information files.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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