title: Biosynthesis of polyhydroxyalkanoates containing hydroxyl group from glycolate in Escherichia coli.
abstract: Polyhydroxyalkanoates (PHAs) containing hydroxyl groups in a side chain were produced in recombinant Escherichia coli JM109 using glycolate as the sole carbon source. The propionate-CoA transferase (pct) gene from Megasphaera elsdenii and the β-ketothiolase (bktB) gene and phaCAB operon from Ralstonia eutropha H16 were introduced into E. coli JM109. A novel monomer containing a hydroxyl group, dihydroxybutyrate (DHBA), was the expected product of the condensation of glycolyl-CoA and acetyl-CoA by BktB. The recombinant strain produced a PHA containing 1 mol% DHBA. The incorporation of DHBA may have been restricted because the expression of phaAB1 competes for acetyl-CoA. The PHA containing DHBA units were evaluated regarding thermal properties, such as melting temperature, glass transition temperature and thermal degradation temperature. The current study demonstrates a potential use of PHA containing hydroxyl groups as renewable resources in biological materials.
authors.affiliation: Enzyme Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
authors.forename: Chayatip
authors.initials: C
authors.lastname: Insomphun
authors.affiliation: Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo, 676-8688, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo, 676-8688, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Fujiki
authors.affiliation: Enzyme Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan. keiji.numata@riken.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Numata
keywords: Escherichia coli; Glycolate; Hydroxyl group; Polyhydroxyalkanoates