Biosynthesis of poly(3-hydroxybutyrate-co-3-mercaptobutyrate) as a Sulfur Analogue to poly(3-hydroxybutyrate) (PHB)

Biomacromolecules. Fall 2001;2(3):1061-5. doi: 10.1021/bm015564p.

Abstract

A hitherto unknown copolymer that contains sulfur in the backbone linking 3-hydroxybutyrate and 3-mercaptobutyrate by thioester linkages, poly(3HB-co-3MB), was synthesized by the polyhydroxyalkanoate-(PHA-) accumulating bacterium Ralstonia eutropha, when 3-mercaptobutyric acid was fed as the carbon source in addition to gluconate. The chemical structure of this novel polymer was confirmed by gas chromatography/mass spectrometry, infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, and elemental sulfur analysis. Different poly(3HB-co-3MB) samples were isolated and characterized, and the molar 3MB fraction contributed up to 72 mol%. Regarding the chemical structure of 3-mercaptobutyrate, which is analogous to 3-hydroxybutyrate, the incorporation of this novel polymer constituent represents a second example of 3-mercaptoalkanoates that are incorporated into biopolymers by the PHA synthase of R. eutropha.

MeSH terms

  • Biopolymers / biosynthesis
  • Biopolymers / chemistry
  • Butyrates / chemistry
  • Cupriavidus necator / metabolism
  • Gas Chromatography-Mass Spectrometry
  • Hydroxybutyrates / chemistry*
  • Hydroxybutyrates / metabolism*
  • Macromolecular Substances
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Polyesters / chemistry*
  • Polyesters / metabolism*
  • Spectroscopy, Fourier Transform Infrared
  • Sulfur / chemistry

Substances

  • Biopolymers
  • Butyrates
  • Hydroxybutyrates
  • Macromolecular Substances
  • Polyesters
  • poly-beta-hydroxybutyrate
  • Sulfur