Characteristic Analysis of Crude and Purified α-amylase from Bacillus licheniformis ATCC 6346 and comparison with Commercial enzyme

Abstract: Thermostable ?-amylases are generally used for industrial applications. The objective of this study is to compare the kinetic properties of crude and purified ?-amylase from Bacillus licheniformis ATCC 6346 with commercial (TermamylR, NOVO industries from Denmark) ?-amylase from Bacillus licheniformis. Commercial and crude ?-amylases showed zero order kinetics for 10 min while purified ?-amylase showed 8 min at pH 7.0 and 85oC. The activities of crude, purified and commercial ?-amylases were measured at different temperatures ranging from 40 to 95oC and the optimum temperature for the activities of crude and purified enzymes was 85oC while that for the commercial enzyme was 90oC. The optimum pH was 7.0 for the crude, purified and commercial enzymes at 85oC. When the crude enzyme was pre-incubated at 85oC and at pH 7.0, it lost 40% of its initial activity at 10 min while the purified enzyme lost 75% of its initial activity at 10 min and the commercial enzyme did not lose activity at 10 min. Half-life of crude and purified ?-amylases were 13.9 and 4.7min respectively while that for commercial enzyme was 823.97 min at pH 7.0 and 85oC. Keywords: Bacillus licheniformis, Zero-order kinetics, ?-amylase, Half-life