Enzymes of Aspergillus Oryzae IV. Fractionation and Preparation of Crystals Rich in Protease

Abstract

Several methods have been examined for the separation of proteases from other enzymes and metabolic products in the culture filtrates obtained by surface culture of Aspergillus oryzae on sucrose-tartrate liquid medium. Concentration, by low-temperature precipitation with ethanol followed by ethanol fractionation of the dialysed concentrate at pH 4-5 in acetate buffer, is shown to be superior' to adsorption methods or precipitation with flavianic acid or ammonium sulphate.