Property And Application Of Resisting Adversity For Polyhydroxyalkanoate Binding Protein PhaP

PhaP (or Phasin) is an amphiphilic protein, and its hydrophobic domains have affinity to the surface of native and artificial polyhydroxyalkanote granule. In this study, we found the pure PhaP (12.6 kDa) of Aeromonas hydrophila was extremely stable at high temperature (upto130oC), ultraviolet, sonication, dryness, freezing/thawing and many solvents (acetone and chloroform). And it was also insensitive to ionic (CTAB) and non-ionic (Tween 20 or 80) surfactants, chelating agent (EDTA), reducer (DTT), oxidizer (H2O2) and saline solution (NaCl). Meanwhile, we further explored the emulsion ability of pure PhaP when coexisted with other surfactants or proteins. In order to reduce the cost of preparing PhaP, bacterial cell lysate with PhaP was directly used in emulsion of diesel. It was satisfactory PhaP can emulsify oils together with surfactants, proteins and bacterial cell lysate. This study implied PhaP could effectively emulsify oils indifferent mixtures, for application as natural and environmentally friendly surfactant for food, pharmaceutical, cosmetic, environmental, and petrochemical industries.