PHA biopolymers are mainly produced by:
Polyhydroxyalkanoates represent family of biodegradable thermoplastic polyesters accumulated intracellularly as carbon and energy storage granules 0.2 to 0.5 micrometer diameter by numerous bacteria under unbalanced growth with excess carbon but limitation of nitrogen, phosphate, magnesium or oxygen. While recombinant Escherichia coli engineered with phaCAB operon can synthesize PHA, native high producers remain Pseudomonas putida, Pseudomonas oleovorans producing medium-chain-length PHA containing monomers C6 to C14 via beta-oxidation pathway involving PhaJ enoyl-CoA hydratase linking fatty a
Ref: Steinbuchel & Lutke-Eversloh 2003 PHA biosynthesis Appl Microbiol Biotech; Nature Reviews Microbiology 2005 biopolymers.