title: Biosynthesis and characterization of 3-hydroxyalkanoate terpolyesters with adjustable properties by Aeromonas hydrophila.
abstract: Polyhydroxyalkanoates (PHA) terployesters P(3HB-co-3HV-co-3HHx) consisting of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx) were produced by wild-type Aeromonas hydrophila 4AK4, its recombinant harboring PHA synthesis genes phaPCJ encoding PHA binding protein phasin, PHA synthase, and enoyl-CoA hydratase, and another its recombinant harboring phaAB encoding beta-ketothiolase and acetoacetyl-CoA reductase, respectively, when grown in lauric acid and/or valerate. The terpolyesters produced by A. hydrophila 4AK4 (phaAB) grown in velarate were found to produce copolymers P(3HB-co-3HV) containing high 3HV fractions with a maximum of 99 mol% 3HV. In terpolyesters, 3HV ranged from 9 to 32 mol% depending on the valerate concentration and strain used. A maximal terpolyester P(3HB-co-3HV-co-3HHx) content in dry cells was 71 wt%. Transmission electron microscopy study of A. hydrophila 4AK4 harboring phaPCJ revealed the full occupation of terpolyester P(3HB-co-3HV-co-HHx) in the cellular spaces. Terpolyesters with various monomer compositions showed changing thermal and mechanical properties. Those with higher 3HV fractions demonstrated an improved property over the lower HV containing ones.
authors.affiliation: Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Zhang
authors.forename: Long
authors.initials: L
authors.lastname: Ma
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Chen
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000032:analysis; D000102:Acetyl-CoA C-Acyltransferase / Q000235:genetics / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000235:genetics / Q000378:metabolism*; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D002208:Caproates / Q000032:analysis; D004746:Enoyl-CoA Hydratase / Q000235:genetics / Q000378:metabolism; D007850:Lauric Acids / Q000378:metabolism; D010421:Pentanoic Acids / Q000032:analysis; D037121:Plant Lectins / Q000235:genetics / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis* / Q000737:chemistry; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014631:Valerates / Q000378:metabolism
chemical_list: D002208:Caproates; D007850:Lauric Acids; D010421:Pentanoic Acids; D037121:Plant Lectins; D011091:Polyesters; D054813:Polyhydroxyalkanoates; D011994:Recombinant Proteins; D014631:Valerates; C045051:3-hydroxyhexanoic acid; C013056:beta-hydroxyvaleric acid; C030358:lauric acid; C008825:phasin; D000429:Alcohol Oxidoreductases; C023744:acetoacetyl-CoA reductase; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase; D000102:Acetyl-CoA C-Acyltransferase; D004746:Enoyl-CoA Hydratase; D020155:3-Hydroxybutyric Acid