title: Polyhydroxybutyrate production from carbon dioxide by cyanobacteria.
abstract: Genetic characterization and enhancement of polyhydroxybutyrate (PHB) accumulation in cyanobacteria were investigated for efficient PHB production from CO2. The genome DNAs in the PHB-accumulating strains Synechococcus sp. MA19 and Spirulina platensis NIES46 retained the highly homologous region to phaC of Synechocystis PCC6803, whereas low homology was detected in the nonaccumulating strains Synechococcus sp. PCC7942 and Anabaena cylindrica NIES19. Synechococcus sp. MA19, which accumulates PHB up to 30% of dry cell weight from CO2 as the sole carbon source, was mutated by insertion of transposon Tn5 to enhance the PHB accumulation. Genetic and physiological analysis of the mutant indicated that decreased phosphotransacetylase activity could trigger an increase of acetyl coenzyme A leading to enhancement of PHB accumulation. PHB synthase in Synechococcus sp. MA19 was probably attached to thylakoid membrane since PHB granules were associated with pigments. A genetically engineered cyanobacteria retaining soluble PHB synthase from Ralstonia eutropha accumulated pigment-free PHB granules, which is an advantage for the purification of PHB.
authors.affiliation: National Institute of Bioscience and Human-Technology, Ibaraki, Japan. mmiyake@nibh.go.jp
authors.forename: M
authors.initials: M
authors.lastname: Miyake
authors.forename: K
authors.initials: K
authors.lastname: Takase
authors.forename: M
authors.initials: M
authors.lastname: Narato
authors.forename: E
authors.initials: E
authors.lastname: Khatipov
authors.forename: J
authors.initials: J
authors.lastname: Schnackenberg
authors.forename: M
authors.initials: M
authors.lastname: Shirai
authors.forename: R
authors.initials: R
authors.lastname: Kurane
authors.forename: Y
authors.initials: Y
authors.lastname: Asada
mesh_terms: D000217:Acyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D017033:Anabaena / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D002245:Carbon Dioxide; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D006885:Hydroxybutyrates / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism; D000091402:Prohibitins; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D006885:Hydroxybutyrates; C000717328:PHB protein, human; D011091:Polyesters; D000091402:Prohibitins; D011994:Recombinant Proteins; D002245:Carbon Dioxide; D000217:Acyltransferases; C060970:poly-beta-hydroxybutyrate polymerase