The paw starch-degrading alpha-amylase of Bacillus sp. IMD 434 was purified to homogeneity by acetone precipitation, ion-exchange chromatography and hydrophobic interaction chromatography. The enzyme had a relative molecular mass of 69,200, displayed maximum activity at pH 6.0 and 65 degrees C and released large amounts of glucose and maltose an hydrolysis of starch.