A biochemical characterization of the tannases from Paecilomyces variotii (produced at Unicamp), Aspergillus niger (purchased from Industrial Kerry Bio-Science) and A. niger cnpat 001 (purchased from Embrapa. Agroindustrial Tropical-Brazil) was carried out. P. variotii is a new strain obtained from the, screening of 500 fungi that were tested for their production of tannase. The biochemical properties of this new tannase from P. variotii were determined and compared with those of two other tannase preparations. The tannase produced from P. variotii showed optimum activity at pH 6.5. The functional temperature range of the tannases was from 20-70 degrees C, with optima at 70 degrees C for P. variotii and at 60 degrees C for the commercially obtained tannase, whereas A. niger cnpat 001 showed optimum activity at 40 degrees C. The effects of 1 mM preparations of cations and anions, inhibitors, surfactants, and chelators on the tannase activity from P. variotii were also studied.162243248