Polyhydroxyalkanoates (PHA), a family of diverse bio-polyesters, are produced by bacteria as an energy and carbon storage material . Many proteins including PHA synthase (PhaC), PHA depolymerase (PhaZ), granule associated protein (PhaP) and repressor protein (PhaR), were reported to attach on the surface of intracellular PHA granules. PhaR has one domain bound to a specific DNA sequence and another to PHB granules. PhaR was also reported able to in vitro bind to both artificial amorphous and crystalline PHB granules tightly ( Yamada et al., 2007), unpurified PhaR in cell lysates of Escherichia coli was able to rebind to PHB granules. More interestingly, PhaR was reported to bind to the surfaces of polystyrene, poly(lactic acid) and polyethylene, demonstrating its non-specific hydrophobic interaction . In addition, PhaR was used as an affinity tag for recombinant protein purification. A similar protein PhaP, the major binding protein on PHA granules, was proven as a bio-surfactant with a high emulsification ability