To exclude a possible unspecific gene deletion that could lead to an absence of PHB production, cells of strain GHH3 were transformed with plasmid pSMF3_RBCP (Additional file 1 : Figure S5), encoding the genes of the PHB-synthesis operon: PHA polymerase subunit phaR, acetoacetyl-CoA reductase phaB, polyhydroxyalkanoic acid inclusion protein phaP and the genomically deleted gene phaC .