Systematically engineering Escherichia coli for enhanced shikimate biosynthesis co‐utilizing glycerol and glucose. (5th March 2018)

• Record Type: Journal Article
• Authors: Bilal, Muhammad; Yue, Shengjie; Hu, Hongbo; Wang, Wei; Zhang, Xuehong
• Is Part Of: Biofuels, bioproducts and biorefining. Volume 12:Number 3(2018)
• Page Start: 348
• Page End: 361
• Publication Date: 2018-03-05
• Subjects: shikimic acid -- Escherichia coli -- metabolic engineering -- glycerol/glucose co‐utilization -- NADPH -- transcription; Biomass energy -- Periodicals; Biological products -- Periodicals; Fuel -- Refining -- Periodicals; 662.8805
• DOI: 10.1002/bbb.1867
• Languages: English
• ISSNs: 1932-104X

Abstract

Abstract: In this study, an Escherichia coli strain with the capability to utilize glycerol/glucose simultaneously was genetically engineered to produce high shikimate. To achieve this, the ptsG gene encoding EIICBglc protein was inactivated in the BW25113 strain to alleviate carbon catabolite repression. The shikimate kinase genes aroK and aroL were also eliminated to construct the SA‐B2 strain, which led to a 42.3% increase in shikimate production. Thereafter, three critical genes, namely mutant aroG fbr, ppsA, and tktA, were overexpressed in strain SA‐B2, and the resulting engineered SA‐B7 strain produced 0.92 g/L shikimate in shake flask cultures, which were 2.5 times higher than strain SA‐B2. The influence of varying carbon mole numbers ratios of glycerol to glucose on the production of shikimate was also investigated, where the highest shikimate production was attained at a glycerol‐to‐glucose ratio of 12:1 by SA‐B7. Moreover, the amount of NADPH was 3.5‐times higher in the mixed culture medium as compared to sole glycerol‐based medium. RT‐PCR data indicated that the addition of glucose upregulated the transcriptional levels of genes pertaining to shikimate biosynthesis. In conclusion, the findings demonstrated that E. coli could be modified as a potential cell factory to produce shikimate and other high‐value derived aromatic compounds by genetic and metabolic engineering strategies. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd