Abstract: Extraction with sodium citrate-citric acid buffer, (NH4)2SO4 fractional precipitation, DEAE-cellulose column separation and Sephadex G-150 column purification were sequentially carried out to obtain an electrophoretically pure extracellular tannase from solid state cultures of Aspergillus niger B0201, with a purification fold of 18.44. The enzyme had a molecular weight of roughly 58800 and the optimum reaction temperature and pH were 40 ℃ and 5.0, respectively. When the substrate was propyl gallate (PG), the Km was 1.08 mmol/L and the Vmax 104.1μmol/(L ·min).

Key words: tannase, fermentation without cooking, purification