Functional expression of phaCAB genes from Cupriavidus taiwanensis strain 184 in Escherichia coli for polyhydroxybutyrate production.

Polyhydroxyalkanoates are polyesters synthesized by numerous microorganisms. These polyesters are biodegradable and have similar properties to those of conventional plastics. Cupriavidus taiwanensis strain 184 is phylogenetically related to the well-known polyhydroxybutyrate (PHB) producer Ralstonia eutropha (Cupriavidus necator) and is also shown to be able to accumulate significant amounts of PHB. In this study, we cloned the PHB synthesis genes (phaCAB) from C. taiwanensis 184 into Escherichia coli for biosynthesis of PHB. The recombinant E. coli strains were able to synthesize significant amounts of PHB. The PHB amounted to about 66~70% of total cell material of these recombinant strains.