The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA.
Bioresour Technol. 2021 Dec;342:125945. doi: 10.1016/j.biortech.2021.125945. Epub 2021 Sep 15.
Transcription factors (TFs) perform a crucial function in the regulation of amino acids biosynthesis. Here, TFs involved in L-glutamate biosynthesis in Corynebacterium glutamicum were investigated. Compared to transcriptomic results of C. glutamicum 13032, 7 TFs regulated to glutamate biosynthesis were indentifed in G01 and E01. Among them, RosR was demonstrated to regulate L-glutamate metabolic network by binding to the promoters of glnA, pqo, ilvB, ilvN, ilvC, ldhA, odhA, dstr1, fas, argJ, ak and pta. Overexpression of RosR in G01 resulted in significantly decreased by-products yield and improved L-glutamate titer (130.6 g/L) and yield (0.541 g/g from glucose) in fed-batch fermentation. This study demonstrated the L-glutamate production improved by the expression of TFs in C. glutamicum, which provided a good reference for the transcriptional regulation engineering of strains for amino acid biosynthesis and suggested further metabolic engineering of C. glutamicum for L-glutamate production.
转录因子 (TFs) 在氨基酸生物合成的调控中发挥着关键作用。本研究探讨了谷氨酸棒状杆菌中参与 L-谷氨酸生物合成的 TFs。与谷氨酸棒状杆菌 13032 的转录组学结果相比，在 G01 和 E01 中鉴定出 7 个调节谷氨酸生物合成的 TFs。其中，RosR 通过结合 glnA、pqo、ilvB、ilvN、ilvC、ldhA、odhA、dstr1、fas、argJ、ak 和 pta 的启动子，调节 L-谷氨酸代谢网络。在 G01 中过表达 RosR 可显著降低副产物产量，提高补料分批发酵中 L-谷氨酸的产量（130.6 g/L）和得率（葡萄糖 0.541 g/g）。本研究表明，在谷氨酸棒状杆菌中表达 TFs 可提高 L-谷氨酸的产量，为氨基酸生物合成菌株的转录调控工程提供了良好的参考，并为进一步进行 L-谷氨酸生产的谷氨酸棒状杆菌代谢工程提供了思路。
