title: Improvement of NADPH bioavailability in Escherichia coli through the use of phosphofructokinase deficient strains.
abstract: NADPH-dependent reactions play important roles in production of industrially valuable compounds. In this study, we used phosphofructokinase (PFK)-deficient strains to direct fructose-6-phosphate to be oxidized through the pentose phosphate pathway (PPP) to increase NADPH generation. pfkA or pfkB single deletion and double-deletion strains were tested for their ability to produce lycopene. Since lycopene biosynthesis requires many NADPH, levels of lycopene were compared in a set of isogenic strains, with the pfkA single deletion strain showing the highest lycopene yield. Using another NADPH-requiring process, a one-step reduction reaction of 2-chloroacrylate to 2-chloropropionic acid by 2-haloacrylate reductase, the pfkA pfkB double-deletion strain showed the highest yield of 2-chloropropionic acid product. The combined effect of glucose-6-phosphate dehydrogenase overexpression or lactate dehydrogenase deletion with PFK deficiency on NADPH bioavailability was also studied. The results indicated that the flux distribution of fructose-6-phosphate between glycolysis and the pentose phosphate pathway determines the amount of NAPDH available for reductive biosynthesis.
authors.affiliation: Department of Biochemistry and Cell Biology, MS-140, Rice University, 6100 Main Street, Houston, TX 77005-1892, USA.
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Ka-Yiu
authors.initials: KY
authors.lastname: San
authors.forename: George N
authors.initials: GN
authors.lastname: Bennett
mesh_terms: D001483:Base Sequence; D001682:Biological Availability; D017931:DNA Primers; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D005285:Fermentation; D009249:NADP / Q000378:metabolism*; D025221:Phosphofructokinases / Q000378:metabolism*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D009249:NADP; D025221:Phosphofructokinases