title: High-level production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by fed-batch culture of recombinant Escherichia coli.
abstract: Fermentation strategies for production of high concentrations of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] with different 3-hydroxyvalerate (3HV) fractions by recombinant Escherichia coli harboring the Alcaligenes latus polyhydroxyalkanoate biosynthesis genes were developed. Fed-batch cultures of recombinant E. coli with the pH-stat feeding strategy facilitated production of high concentrations and high contents of P(3HB-co-3HV) in a chemically defined medium. When a feeding solution was added in order to increase the glucose and propionic acid concentrations to 20 g/liter and 20 mM, respectively, after each feeding, a cell dry weight of 120.3 g/liter and a relatively low P(3HB-co-3HV) content, 42.5 wt%, were obtained. Accumulation of a high residual concentration of propionic acid in the medium was the reason for the low P(3HB-co-3HV) content. An acetic acid induction strategy was used to stimulate the uptake and utilization of propionic acid. When a fed-batch culture and this strategy were used, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 141.9 g/liter, 88.1 g/liter, 62.1 wt%, and 15.3 mol%, respectively. When an improved nutrient feeding strategy, acetic acid induction, and oleic acid supplementation were used, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 203.1 g/liter, 158.8 g/liter, 78.2 wt%, and 10.6 mol%, respectively; this resulted in a high level of productivity, 2.88 g of P(3HB-co-3HV)/liter-h.
authors.affiliation: Department of Chemical Engineering and BioProcess Engineering Research Center, Korea Advanced Institute of Science and Technology, 373-1, Kusong-dong, Yusong-gu, Taejon 305-701, Korea.
authors.forename: J I
authors.initials: JI
authors.lastname: Choi
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D019342:Acetic Acid / Q000494:pharmacology; D001673:Biodegradation, Environmental; D004926:Escherichia coli / Q000235:genetics*; D019301:Oleic Acid / Q000494:pharmacology; D010421:Pentanoic Acids / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism; D011995:Recombination, Genetic
chemical_list: D010421:Pentanoic Acids; D011108:Polymers; D011422:Propionates; C013056:beta-hydroxyvaleric acid; D019301:Oleic Acid; C029658:propionic acid; D019342:Acetic Acid; D020155:3-Hydroxybutyric Acid