An inclusion body located in the cytoplasm of prokaryotes that consists of polyhydroxyalkanoate (PHA) molecules and associated proteins, surrounded by a phospholipid monolayer; the proteins include PHA synthase, PHA depolymerase and 3HB-oligomer hydroxylase, phasins (PhaPs), which are thought to be the major structural proteins of the membrane surrounding the inclusion, and the regulator of phasin expression PhaR. [ GOC:mah http://www.ncbi.nlm.nih.gov/pubmed/15762612 ]