Liquid-Liquid Partitioning Methods for

extraction which is used for the separations of many metabolites from fermentation such as alcohols, carbox~lic acids, amino acids, and anti-b io t i c ~. '. ~ The other is the aqueous two-phase partitioning using water soluble polymers such as polyethylene glycol (PEG) and dextran, and salts such as potassium phosphate. The latter method is very attractive for the separation of biomolecules such as proteins and peptides including many e n ~ y m e s ~- ~ that may be denatured by solvents. As the scale of bioseparation processes goes up, liquid-liquid partitioning becomes more and more com-petitive because it is easy to scale up and it permits continuous steady-state pera at ion. ^ The cost for liquid-liquid partitioning is much lower than other more sophisticated bioseparations method, such as liquid chromatography