Purification And Characterization Of α-Acetolactate Decarboxylase From Bacillus Subtilis

α -Acetolactate decarboxylase are widely found among bacterial strains but not in other groups of organisms. The enzyme has been demonstrated to be effective for removal of acetolactate and widely used in beer product. In this paper, α-Acetolactate decarboxylase from Bacillus subtilis was purifed to homogeneity from cell extract by ammonium sulfate-fractionation, heat treatment, DEAE-Sepharose Fast Flow column chromatography. The characterization of the Acetolactate decarboxylase is also reported.α-Acetolactate decarboxylase is purifed from cell extract by 50 % - 80% ammonium sulfate-fractionation, 50℃, 2min heat treatment and DEAE-Sepharose Fast Flow column chromatography, which we study the different pH and different buffer of DEAE-Sepharose Fast Flow column chromatography and conclude pH 6. 0 MES buffer is the most efficient. The elution point is 0.24-0.32mol/L·NaCl. The enzyme is purified about 15. 5-fold. Its molecular weight is estimated to be about 32Kda by SDS-PAGE. It showed optimal activity at pH 7.0. The enzyme showed stability at pH 7. 0 and the temperature below 40℃. Kinetics parameter of α-Acetolactate decarboxylase is Km=232. 6mmol/L and Vmax=7.1 μ mol/(μ g. mm). Mg2+ , Mn2+ , Zn2+, Fe2+, Fe3+, Cu2+ have enabled effect on enzyme activation and EDTA produce a strong inhibitory effect on the enzyme. Embranch amino acid have no effect on the enzyme.