Properties of engineered poly-3-hydroxyalkanoates produced in recombinant Escherichia coli strains
Properties of engineered poly-3-hydroxyalkanoates produced in recombinant Escherichia coli strains
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DOI：
10.1128/aem.66.4.1311-1320.2000
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发表时间：
2000-04-01
影响因子：
4.4
通讯作者：
Witholt, B
中科院分区：
文献类型：
--
作者：
Ren, Q;Sierro, N;Witholt, B
To prepare medium-chain-length poly-3-hydroxyalkanoates (PHAs) with altered physical properties, we generated recombinant Escherichia coli strains that synthesized PHAs,with altered monomer compositions. Experiments with different substrates (fatty acids with different chain lengths) or different E. coli hosts failed to produce PHAs with altered physical properties. Therefore, we engineered a new potential PHA synthetic pathway, in which ketoacyl-coenzyme A (CoA) intermediates derived from the alpha-oxidation cycle are accumulated and led to the PHA polymerase precursor R-3-hydroxyalkanoates in E. coli bests. By introducing the poly-3-hydrolybutylate acetoacetyl-CoA reductase (PhbB) from Ralstonia eutropha and blocking the ketoacyl-CoA degradation step of the beta-oxidation, the ketoacyl-CoA intermediate was accumulated and reduced to the PHA precursor. Introduction of the phbB gene not only caused significant changes in the monomer composition but also caused changes of the physical properties of the PHA, such as increase of polymer size and loss of the melting point. The present study demonstrates that pathway engineering can be a useful approach for producing PHAs with engineered physical properties.
