Calvatia gigantea, an edible puffball, was grown well on simple phenolic compounds and hydrolysable and condensed tannins as sole carbon sources. A new enzymic system was found to be involved in the degradation of catechin, the building unit of condensed tannins. This enzymic system was induced by catechin and displayed no phenoloxidase activity. Crude enzymic preparation functioned optimally at pH 7.5–8.0 and 40–45°C and had an apparentKm, 2.96 × 10−5 M at pH 8.0. The results of this work makeC. gigantea a potential microorganism for the degradation of toxic phenolic and polyphenolic compounds and particularly condensed tannins.