Study on Nattokinase-Extraction with two-phase aqueous system

Abstract. The extraction of nattokinase with two-phase aqueous system was studied.Distribution behavior of nattokinase with PEG400/(NH4)2SO4 and PEG6000/MgSO4 two-phase aqueous systems were studied respectively. PEG400/(NH4)2SO4 two-phase aqueous system is suitable for the extraction of nattokinase. Various factors affecting the extraction of nattokinase with PEG400/(NH4)2SO4 two-phase aqueous system were studied. The mass fraction of PEG400 was determined to be 24%, The mass fraction of (NH4)2SO4 was determined to be 27%, the addition of crude enzyme was determined to be 15%. Under these conditions,purification of nattokinase reached 2.11