The recovery of poly(3-hydroxybutyrate) [PHB] from Alcaligenes eutrophus and a recombinant Escherichia coli strain harboring the A. eutrophus poly(3-hydroxyalkanoates) biosynthesis genes was studied. When PHB was recovered using sodium hypochlorite or sodium dodecyl sulfate (SDS), non-PHB cell materials (NPCM) of the recombinant E. coli seemed to be more easily digested than those of A. eutrophus. Furthermore, viscosity increase caused by cell lysis during SDS treatment was negligible for the recombinant E. coli, whereas a very viscous suspension was formed for A. eutrophus. These results, together with our previous finding that PHB in the recombinant E. coli is far less susceptible to molecular degradation by sodium hypochlorite, suggested that the recombinant E. coli was more beneficial than A. eutrophus in teams of PHB recovery. In order to develop an easy and efficient recovery process, we adopted and optimized the SDS treatment since, with the hypochlorite treatment, we could not handle high biomass concentrations effectively. We could obtain a PHB of 95 % purity with 96 % recovery under the optimal condition of a biomass concentration of 5 %, a ratio of SDS to biomass of 0.6, a treatment time of 60 minutes, and a treatment temperature of 30℃.