Purification and Characterization of Heterogeneous Glucoamylases from Monascus purpureus

Abstract

Two forms of an extracellular glucoamylase, MpuGA-I and MpuGA-II, were purified to homogeneity from Monascus purpureus RY3410. The molecular weights of these enzymes were estimated to be 60,000 (MpuGA-I) and 89,000 (MpuGA-II). These enzymes were glycoproteins with a carbohydrate content of 15.0% (MpuGA-I) and 16.2% (MpuGA-II) respectively. The pH optima were 5.0 for both enzymes, and the optimal temperatures were 50 °C (MpuGA-I) and 65 °C (MpuGA-II). The K_m values for soluble starch were calculated to be 4.0±0.8 mg/ml (MpuGA-I) and 1.1±0.2 mg/ml (MpuGA-II) respectively.