title: Effects of pH of fermentation medium on biosynthesis of poly[(3-hydroxybutyrate)-co-(3-mercaptopropionate)] by Wautersia eutropha.
abstract: A series of P(3HB-co-3MP)s with different 3MP unit content was biosynthesized by the fermentation of W. eutropha in a medium containing sodium gluconate and DTDP as carbon sources at different pH conditions ranging from pH 6.0 to 8.0. The P(3HB-co-3MP) samples were fractioned using the solvent/nonsolvent mixed solvent chloroform/heptane and the comonomer unit composition was investigated. It was found that W. eutropha produces P(3HB-co-3MP)s with extremely different 3MP unit content ranging from 3.6 to 70.0 mol-%, depending on the pH value of the fermentation medium. The copolyester samples produced in mild basic medium have a considerably narrower compositional distribution than the samples from acidic medium. The highest polymer yield was obtained at pH 8.0.DSC diagram for P(3HB-co-3MP)s biosynthesized in different pH medium. [graph: see text] DSC diagram for P(3HB-co-3MP)s biosynthesized in different pH medium.
authors.affiliation: Department of Biomolecular Engineering, Tokyo Institute of Technology, Nagatsuta 4259-B-55, Yokohama 226-8501, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Isemori
authors.forename: Koichiro
authors.initials: K
authors.lastname: Tajima
authors.forename: Syogo
authors.initials: S
authors.lastname: Tanaka
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ishida
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000737:chemistry / Q000302:isolation & purification*; D015097:3-Mercaptopropionic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification*; D005591:Chemical Fractionation; D020118:Cupriavidus necator / Q000737:chemistry*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D006885:Hydroxybutyrates; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D013997:Time Factors
chemical_list: D006885:Hydroxybutyrates; D011108:Polymers; D015097:3-Mercaptopropionic Acid; D020155:3-Hydroxybutyric Acid