Multiplicity of Glucoamylase of Aspergillus oryzae Part 2. Enzymatic and Physicochemical Properties of Three Forms of Glucoamylase

Three forms of glucoamylase of Aspergillus oryzae had optimum pH range between 4.5 to 5.0 at 40°C and optimum temperature range between 40 and 60°C. They were most stable at pH range between 4.0 and 7.0 and temperatures up to 40°C. The molecular weights were 76.000, 38.000 and 38.000, respectively. Hydrolysis activities of the three glucoamylases on different substrates were studied. They differed in their rate of attack on many substrates. Glucoamylase I had strong debranching activity and was highly active in raw corn starch digestion. Glucoamylase II and III had weak debranching activities and could hardly digest raw starch.