Studies on Amylases of Aspergillus oryzae Cultured on Rice

α-Amylase was purified from a culture of Aspergillus oryzae on steamed rice by means of ion exchange chromatography on DEAE-Sephadex, and the purified enzyme was crystallized with ammonium sulfate. The preparation was found to be homogeneous by means of sedimentation and disc electrophoretic analyses. The enzyme was revealed to have strong α-amylase activity by the dinitrosalicylate method and the iodine color method. Large single crystals of the enzyme were prepared by making the concentrated enzyme solution to 0.41 saturation of ammonium sulfate at pH 5.0. A brief communication on the preliminary X-ray crystallography was also presented.