title: Improvement of shikimic acid production in Escherichia coli with growth phase-dependent regulation in the biosynthetic pathway from glycerol.
abstract: Shikimic acid is an important metabolic intermediate with various applications. This paper presents a novel control strategy for the construction of shikimic acid producing strains, without completely blocking the aromatic amino acid biosynthesis pathways. Growth phase-dependent expression and gene deletion was performed to regulate the aroK gene expression in the shikimic acid producing Escherichia coli strain, SK4/rpsM. In this strain, the aroL and aroK genes were deleted, and the aroB, aroG*, ppsA, and tktA genes were overexpressed. The relative amount of shikimic acid that accumulated in SK4/rpsM was 1.28-fold higher than that in SK4/pLac. Furthermore, a novel shikimic acid production pathway, combining the expression of the dehydroquinate dehydratase-shikimate dehydrogenase (DHQ-SDH) enzyme from woody plants, was constructed in E. coli strains. The results demonstrated that a growth phase-dependent control of the aroK gene leads to higher SA accumulation (5.33 g/L) in SK5/pSK6. This novel design can achieve higher shikimic acid production by using the same amount of medium used by the current methods and can also be widely used for modifying other metabolic pathways.
authors.affiliation: Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Kweishan, Taoyuan, Taiwan.
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan.
authors.forename: Wen-Pin
authors.initials: WP
authors.lastname: Hung
authors.affiliation: Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan. d92b47401@ntu.edu.tw.
authors.forename: Shu-Hsien
authors.initials: SH
authors.lastname: Tsai
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D053898:Biosynthetic Pathways; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005990:Glycerol / Q000378:metabolism*; D007700:Kinetics; D060847:Metabolic Engineering; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics; D050743:Pyruvate Synthase / Q000235:genetics / Q000378:metabolism; D012765:Shikimic Acid / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D010940:Plant Proteins; D012765:Shikimic Acid; D000429:Alcohol Oxidoreductases; D050743:Pyruvate Synthase; C506224:ppsA protein, E coli; D017853:Phosphotransferases (Alcohol Group Acceptor); C022642:shikimate kinase; D005990:Glycerol
keywords: AroK gene; Biosynthetic pathway; Escherichia coli; Metabolic engineering; Shikimic acid