title: Application of an oxygen-inducible nar promoter system in metabolic engineering for production of biochemicals in Escherichia coli.
abstract: The nar promoter, a dissolved oxygen (DO)-dependent promoter in Escherichia coli, is simply induced and functional in any cell growth phase, which are advantageous for producing biochemicals/fuels on an industrial scale. To demonstrate the feasibility of using the nar promoter in the metabolic engineering of biochemicals/biofuels in E. coli, three target pathways were examined: the d-lactate, 2,3-butandiol (2,3-BDO), and 1,3-propanediol (1,3-PDO) pathways consisting of one, three, and six genes, respectively. Each pathway gene was expressed under the control of the nar promoter. When the ldhD gene was expressed in fed-batch culture, the titer, yield, and productivity of d-lactate were 113.12 ± 2.37 g/L, 0.91 ± 0.07 g/g-glucose, and 4.19 ± 0.09 g/L/h, respectively. When three 2,3-BDO pathway genes (ilvBN, aldB, bdh1) were expressed in fed-batch culture, the titer, yield, and productivity of (R,R)-2,3-BDO were 48.0 ± 8.48 g/L, 0.43 ± 0.07 g/g glucose, and 0.76 ± 0.13 g/L/h, respectively. When six 1,3-PDO pathway genes (dhaB1B2B3, yqhD, gdrA, and gdrB) were expressed in fed-batch culture, the titer, yield, and productivity of 1,3-PDO were 15.8 ± 0.62 g/L, 0.35 ± 0.01 g/g-glycerol, and 0.25 ± 0.01 g/L/h, respectively. Based on the reasonable performance comparable to that observed in previous studies using different promoters in metabolic engineering, the nar promoter can serve as a controlled expression tool for developing a microbial system to efficiently produce biochemicals and biofuels. Biotechnol. Bioeng. 2017;114: 468-473. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Woncheon-dong, Yeongtong-gu, Suwon, 443-749, South Korea.
authors.forename: Hee J
authors.initials: HJ
authors.lastname: Hwang
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Woncheon-dong, Yeongtong-gu, Suwon, 443-749, South Korea.
authors.forename: Jin W
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Woncheon-dong, Yeongtong-gu, Suwon, 443-749, South Korea.
authors.forename: Si Y
authors.initials: SY
authors.lastname: Ju
authors.affiliation: BioMaterials Lab, Samsung Advanced Institute of Technology, Suwon, 443-803, South Korea.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Woncheon-dong, Yeongtong-gu, Suwon, 443-749, South Korea.
authors.forename: Pyung C
authors.initials: PC
authors.lastname: Lee
mesh_terms: D002072:Butylene Glycols / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics*; D060847:Metabolic Engineering / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011409:Propylene Glycols / Q000378:metabolism
chemical_list: D002072:Butylene Glycols; D029968:Escherichia coli Proteins; D011409:Propylene Glycols; C026978:2,3-butylene glycol; C041787:1,3-propanediol; D010100:Oxygen
keywords: 1,3-propandiol; 2,3-butanediol; lactate; nar promoter