Purification, biochemical characterization and application of α-amylase produced by Aspergillus oryzae IFO-30103

α-Amylase from Aspergillus oryzae IFO-30103 was purified through acetone precipitation, Sephadex G-100 and DEAE-cellulose columns sequentially for biochemical characterization. A very high purity (7.1-fold of purification with 40% yield) of α-amylase with molecular weight 51.3 kDa was obtained exploiting this three-step purification process. The purified enzyme showed stability at the pH range of 4.5–7.2 with optimum pH 5.5. In presence of 10 mM CaCl2 the enzyme retained 61.9% activity even after 8 h of incubation at optimum temperature 50 °C. Although Ca2+ is a good stabilizer but could not activate the enzyme significantly however Co2+ was proved to be a very good activator. Interestingly the enzyme was highly stable in some alcohols. Enzyme kinetics of purified α-amylase revealed Km and Vmax values of 0.5% and 1000 U/mg protein for soluble starch. The purified α-amylase was successfully utilized for the improvement of antioxidant potential of wheat.