title: Effect of overexpression of a soluble pyridine nucleotide transhydrogenase (UdhA) on the production of poly(3-hydroxybutyrate) in Escherichia coli.
abstract: A soluble pyridine nucleotide transhydrogenase (UdhA) has been used to increase the productivity and yield of PHB in vivo. By inducing a high level of UdhA, which can transfer reducing equivalents between NAD and NADP, we have increased NADPH availability, resulting in high yield and productivity of PHB in Escherichia coli. Coexpression of the phb operon from Alcaligenes eutrophus H16 and the native udhA from E. coli from high copy plasmids resulted in an increase in PHB yield from 49 to 66% g of PHB per gram of total cell dry weight and an increase in final concentration from 3.52 to 6.42 g/L; the PHB concentration of the udhA carrying strain is almost twice that of the control strain expressing only the phb operon. The results of this study demonstrate the effectiveness of cofactor manipulation and its application as a tool in metabolic engineering.
authors.affiliation: Departments of Bioengineering, Biochemistry and Cell Biology, and Mathematics, Rice University, Houston, Texas 77005, USA.
authors.forename: Ailen M
authors.initials: AM
authors.lastname: Sanchez
authors.forename: Jared
authors.initials: J
authors.lastname: Andrews
authors.forename: Insiya
authors.initials: I
authors.lastname: Hussein
authors.forename: George N
authors.initials: GN
authors.lastname: Bennett
authors.forename: Ka-Yiu
authors.initials: KY
authors.lastname: San
mesh_terms: D004926:Escherichia coli / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D005947:Glucose / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009250:NADP Transhydrogenases / Q000235:genetics / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D012995:Solubility; D000094122:Polyhydroxybutyrates
chemical_list: D005947:Glucose; D006885:Hydroxybutyrates; D009243:NAD; D009250:NADP Transhydrogenases; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates