title: Metabolic engineering of Ralstonia eutropha for the biosynthesis of 2-hydroxyacid-containing polyhydroxyalkanoates.
abstract: Polyhydroxyalkanoates (PHAs) are bio-based and biodegradable polyesters synthesized by numerous microorganisms. PHAs containing 2-hydroxyacids as monomer units have attracted much attention, but their production has not been efficient. Here, we metabolically engineered Ralstonia eutropha strains for the in vivo synthesis of PHAs containing 2-hydroxyacids as monomers. This was accomplished by replacing the R. eutropha phaC gene in the chromosome with either the R. eutropha phaC S506G A510K gene, which contains two point mutations, or the Pseudomonas sp. MBEL 6-19 phaC1437 gene. In addition, the R. eutropha phaAB genes in the chromosome were replaced with the Clostridium propionicum pct540 gene. All of the engineered R. eutropha strains produced PHAs containing 2-hydroxyacid monomers, including lactate and 2-hydroxybutyrate (2HB), along with 3-hydroxybutyrate (3HB) and/or 3-hydroxyvalerate (3HV), when they were cultured in nitrogen-free medium containing 5 g/L lactate or 4 g/L 2HB and 20 g/L glucose as carbon sources. Expression of the Escherichia coli ldhA gene in engineered R. eutropha strains allowed production of poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] from glucose as the sole carbon source. This is the first report on the production of 2-hydroxyacid-containing PHAs by metabolically engineered R. eutropha.
authors: Department of Environmental Engineering and Energy, Myongji University, San 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido 449-728, Republic of Korea; Department of Energy and Biotechnology, Myongji University, San 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido 449-728, Republic of Korea.
authors: Si Jae
authors: SJ
authors: Park
authors: Young-Ah
authors: YA
authors: Jang
authors: Hyuk
authors: H
authors: Lee
authors: A-Reum
authors: AR
authors: Park
authors: Jung Eun
authors: JE
authors: Yang
authors: Jihoon
authors: J
authors: Shin
authors: Young Hoon
authors: YH
authors: Oh
authors: Bong Keun
authors: BK
authors: Song
authors: Jonggeon
authors: J
authors: Jegal
authors: Seung Hwan
authors: SH
authors: Lee
authors: Sang Yup
authors: SY
authors: Lee
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D020118:Cupriavidus necator / Q000235:genetics / Q000378:metabolism; D060847:Metabolic Engineering; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D054813:Polyhydroxyalkanoates
keywords: 2-hydroxyacid; 2-hydroxybutyrate; Lactate; PHA; Ralstonia eutropha