Patent ID: 7019120

Claim:
A method of extracting a hydrophobic polypeptide of interest from a fermentation broth comprising: i) adjusting the pH of the hydrophobic polypeptide of interest to a pH in the range of 3 pH units less than the pI of the hydrophobic polypeptide of interest to 1 pH unit greater than the pI of the hydrophobic polypeptide of interest; ii) adding a non-ionic surfactant with a hydrophile-lipophile balance (HLB) of 12 or lower; iii) cooling the mixture of the hydrophobic polypeptide of interest and the non-ionic surfactant for solubilization and incubating at above cloud point for extraction; iv) phase separating at below cloud point to obtain liquid-liquid-solid fractions; and v) recovering the surfactant-rich top phase containing the hydrophobic polypeptide of interest.