Abstract:
This work attempts to study and optimize aqueous two-phase system (ATPS) made of PEG, sodium carbonate and PEG, sodium sulphate. Three factors ;PEG concentration, salt concentration and pH affecting the papain partitioning were studied. The statistical analysis showed that for both systems the phase forming salt concentration significantly affect the �K� value for papain partitioning. However, the performance of PEG/Na2CO3 system was generally better than PEG/Na2SO4 system. Hence, detail study was carried out on the PEG/Sodium carbonate system using CCRD (Central Composite Rotatable Design) in Response Surface Methodology (RSM). The optimal condition gave a �K� value of partitioning of 1.51 with a yield of 76%.

Keywords:Aqueous two-phase system, Polyethylene glycol, Sodium Carbonate, Central composite design