title: Biosynthesis of novel terpolymers poly(lactate-co-3-hydroxybutyrate-co-3-hydroxyvalerate)s in lactate-overproducing mutant Escherichia coli JW0885 by feeding propionate as a precursor of 3-hydroxyvalerate.
abstract: Novel lactate (LA)-based terpolymers, P[LA-co-3-hydroxybutyrate(3HB)-co-3-hydroxyvalerate(3HV)]s (PLBVs), were produced in LA-overproducing mutant, Escherichia coli JW0885, which was found to be a superior host for the efficient production of LA-based polyesters. Recombinant E. coli JW0885 harboring the genes encoding LA-polymerizing enzyme (Ser325Thr/Gln481Lys mutant of polyhydroxyalkanoate synthase from Pseudomonas sp. 61-3) and three monomer supplying enzymes [propionyl-CoA transferase, beta-ketothiolase, and nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH)-dependent acetoacetyl-CoA reductase] was aerobically grown on glucose with feeding of propionate as a precursor of 3-hydroxyvaleryl-CoA (3HV-CoA). Gas chromatography and nuclear magnetic resonance (NMR) analyses revealed that polymers accumulated in the cells were composed of LA, 3HB, and 3HV units, thus being identified as terpolymers, PLBVs. In addition, (1)H-NMR analysis suggested the existence of LA-3HV sequence in the terpolymer. When 100 mg/l of sodium propionate was added into the medium, 3HV fraction in the terpolymer linearly reached up to 7.2 mol%, while LA fraction was inversely decreased. This phenomenon could be due to the change in metabolic fluxes of lactyl-CoA (LA-CoA) and 3HV-CoA depending on the concentration of propionate fed into the medium.
authors: Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, Kita-ku, Sapporo, Japan.
authors: Fumi
authors: F
authors: Shozui
authors: Ken'ichiro
authors: K
authors: Matsumoto
authors: Takanori
authors: T
authors: Nakai
authors: Miwa
authors: M
authors: Yamada
authors: Seiichi
authors: S
authors: Taguchi
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008970:Molecular Weight; D010421:Pentanoic Acids / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism*; D011995:Recombination, Genetic
chemical_list: D010421:Pentanoic Acids; D011091:Polyesters; D011422:Propionates; C548828:poly(lactate-co-3-hydroxybutyrate-co-3-hydroxyvalerate); C013056:beta-hydroxyvaleric acid; D019344:Lactic Acid; D020155:3-Hydroxybutyric Acid