Bacterial synthesis of PHA block copolymers.

Polyhydroxyalkanoates (PHA) containing block copolymers were synthesized in Cupriavidus necator using periodic substrate addition. Poly(3-hydroxybutyrate) (PHB) segments were formed during fructose utilization. Pulse feeds of pentanoic acid resulted in the synthesis of 3-hydroxyvalerate monomers, forming poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) random copolymer.

Mass spectrometry feedback control for synthesis of polyhydroxyalkanoate granule microstructures in Ralstonia eutropha.

Polyhydroxyalkanoate (PHA) granules with core-shell layered microstructure were synthesized in Ralstonia eutropha using periodic feeding of valeric acid into a growth medium containing excess fructose. The O2 consumption and CO2 evolution rates, determined by off-gas mass spectrometry, have been used as sensitive measures to indicate the type of nutrients utilized by R. eutropha during PHA synthesis.