title: Enhancement of poly-3-hydroxybutyrate production in Synechocystis sp. PCC 6803 by overexpression of its native biosynthetic genes.
abstract: Synechocystis sp. PCC 6803 strains overexpressing pha genes were constructed and characterized for poly-3-hydroxybutyrate (PHB) production. These pha overexpressing strains showed slightly reduced growth rates. Under N-deprived condition, the strains overexpressing (OE) phaAB, phaEC and phaABEC showed significantly higher PHB contents than the wild type. The maximum PHB content, a 2.6-fold increase producing 26% PHB (dcw), was observed in OE phaAB cells grown for 9days in N-deprived medium. Under this condition, these OE phaAB cells increased PHB production to 35% PHB (dcw) upon addition of 0.4% (w/v) acetate. Higher PHB granules in OE phaAB cells were clearly visualized by both Nile red staining and TEM imaging. All OE strains under N-deficient condition had increased glgX transcript levels. Overall results demonstrate an enhanced PHB production in Synechocystis cells overexpressing pha genes, particularly phaA and phaB, when grown in N-deprived medium containing 0.4% (w/v) acetate.
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Division of Biology, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi, Thanyaburi, Pathumthani 12110, Thailand.
authors.forename: Wanthanee
authors.initials: W
authors.lastname: Khetkorn
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Aran
authors.initials: A
authors.lastname: Incharoensakdi
authors.affiliation: Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Box 523, SE-75120 Uppsala, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Lindblad
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: saowarath.j@chula.ac.th.
authors.forename: Saowarath
authors.initials: S
authors.lastname: Jantaro
mesh_terms: D000085:Acetates / Q000737:chemistry; D001709:Biotechnology; D002851:Chromatography, High Pressure Liquid; D005818:Genetic Engineering; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D010788:Photosynthesis; D010957:Plasmids / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D000072417:Protein Domains; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D000085:Acetates; D006885:Hydroxybutyrates; D011091:Polyesters; D011108:Polymers; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: Polyhydroxybutyrate; Synechocystis sp. PCC 6803; pha overexpression