Extracellular proteinases of Aspergillus oryzae.

Although the production of proteolytic enzymes by different strains of Aspergillus oryzae has been investigated in submerged culture (5, 15), in static liquid culture (3, 11), and on solid substratum (8-10), there appear to be few reports pertaining to the comparative evaluation of these different methods on the elaboration of proteinases by specific strains of A. oryzae. K. Mogi (13) compared the proteinase activity of a few strains grown in submerged culture and on solid substratum and found the submerged culture superior. The properties of proteinases produced by A. oryzae under various conditions rich fraction, which was then suspended in water and fractionated with ammonium sulfate. The proteinase-rich fraction thus obtained was resuspended in water, dialyzed against several changes of distilled water, and further fractionated with alcohol to obtain solid, needleshaped crystals having higher proteinase activity. Repeated attempts to crystallize this enzyme by the method of Crewther and Lennox (3) failed. Proteinase activities were determined by viscosity reduction (7), gelatin digestion (17), hemoglobin digestion (1), and caseinolysis (2).