A Pseudomonas sp. 61-3 malonyl-CoA-ACP transacylase gene (fabD(Ps)) was cloned by Southern analysis using an equivalent gene of Escherichia coli (fabD(Ec)) as a probe. Some recombinant E. coli HB101 strains harboring fabD(Ps), fabD(Ec), or E. coli 3-ketoacyl-ACP synthase III gene (fabH(Ec)) with Aeromonas caviae polyhydroxyalkanoate synthase gene (phaC(Ac)) were constructed and grown on one-stage cultivation in Luria-Bertani broth containing glucose as carbon source. These strains accumulated 5 to 11 wt% of poly (3-hydroxybutyrate) (PHB) within cells. Over-expression of fabH(Ec), fabD(Ec), or fabD(Ps) has been suggested to lead the monomer-supply of (R)-3-hydroxybutyryl-CoA for PHB synthesis in E. coli cells.