Formation of short chain length/medium chain length polyhydroxyalkanoate copolymers by fatty acid beta-oxidation inhibited Ralstonia eutropha
| Autor: | Joe Kemper, Ling Guo, Mike Satkowski, Phillip Richard Green, Silke Fiedler, and Alexander Steinbüchel, Lee Schechtman, Bernd H. A. Rehm |
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| Rok vydání: | 2002 |
| Předmět: |
Chromatography
Gas Polymers and Plastics Polymers Polyesters Bioengineering Fatty acid beta-oxidation Polyhydroxyalkanoates Gas Chromatography-Mass Spectrometry Biomaterials Ralstonia Materials Chemistry Escherichia coli Organic chemistry Cells Cultured chemistry.chemical_classification biology 3-Hydroxybutyric Acid Chemistry Fatty Acids Wild type Fatty acid Polymer biology.organism_classification Recombinant Proteins Acrylates Proton NMR Cupriavidus necator Oxidation-Reduction Bacteria Acyltransferases Plasmids |
| Zdroj: | Biomacromolecules. 3(1) |
| ISSN: | 1525-7797 |
| Popis: | Ralstonia eutropha has been considered as a bacterium, incorporating hydroxyalkanoates of less than six carbons only into polyhydroxyalkanoates (PHAs). Cells of the wild type cultivated with sodium octanoate as the carbon source in the presence of the fatty acid beta-oxidation inhibitor sodium acrylate synthesized PHAs composed of the medium chain length hydroxyalkanoates (3HA(MCL)) 3-hydroxyhexanoate (3HHx) and 3-hydroxyoctanoate (3HO) as well as of 3-hydroxybutyrate and 3-hydroxyproprionate as revealed by gas chromatography, (1)H NMR spectroscopy, and mass spectroscopy. The characterization of the polymer as a tetrapolymer was confirmed by differential solvent extraction and measurement of melting and glass transition temperature depression in the purified polymer compared to PHB. These data suggested that the R. eutropha PHA synthase is capable of incorporating longer chain substrates than suggested by previous in vitro studies. Furthermore, expression of the class II PHA synthase gene phaC1 from P. aeruginosa in R. eutropha resulted in the accumulation of PHAs consisting of 3HA(MCL) contributing about 3-5% to cellular dry weight. These PHAs were composed of nearly equal molar fractions of 3HO and 3-hydroxydecanoate (3HD) with traces of 3HHx. These data indicated that 3HA(MCL)-CoA thioesters were diverted from the fatty acid beta-oxidation pathway towards PHA biosynthesis in recombinant R. eutropha. |
| Databáze: | OpenAIRE |
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