Extraction of Dextranase by PEG/(NH_4)_2SO_4 Aqueous Two-Phase Systems

In the PEG(polyethylene glycol)/(NH4)2SO4 aqueous two-phase system,the effects of the PEG molecular weight,PEG and ammonium sulfate concentration on the dextranase extraction were studied.According to parameters of dextranase activity,protein concentration,specific activity and extraction rate,we can find the best technological parameter.The results indicated that the best PEG molecular weight was 4000,the best PEG4000 concentration was 13%,and the best ammonium sulfate concentration was 13%.In this condition,specific activity of end product is 2364.97 U/mg and extraction rate is 99.94%.