Engineered strain of Escherichia coli for production of poly-R-3-hydroxyalkanoate polymers with defined monomer unit composition and methods based thereon

摘要

Methods and systems for producing prescribed unit size azido-poly(3-hydroxyalkanoate) (azido-PHA) polymers and copolymers are provided. The methods and systems can employ recombinant bacteria that are not native producers of PHA or lack enzymes to degrade PHA once synthesized, metabolize short to long chain fatty acids without induction, and express an (R)-specific enoyl-CoA hydratase and a PHA synthase, the (R)-specific enoyl-CoA hydratase and PHA synthase having wide substrate specificities. The recombinant bacteria are fed at least one ω-azidofatty acid substrate that is equal in carbon length to the prescribed or desired unit size of an azido-PHA polymer to be produced. Azido-PHA polymers or azido-PHA co-polymers can be conjugated via copper-catalyzed alkyne-azide cycloaddition (CuAAC) or strain-promoted azide-alkyne cycloaddition (SPAAC) reactions. The prescribed unit size conjugated azido-PHA polymer or orthogonally conjugated azido-PHA co-polymer that is produced is then isolated and/or purified.