Two isoforms of laccase produced from the culture supernatant of Pycnoporus sanguineus were partially purified by phenyl-Sepharose chromatography. Molecular masses of the enzymes were 80 kDa (Lac I) and 68 kDa (Lac II). Optimum activity of Lac I was at pH 4.8 and 30 degrees C, and Lac II was at pH 4.2 and 50 degrees C over 5 min reaction. The K-m values of enzymes toward syringaldazine were 10 mu=M (Lac I) and 8 mu M (Lac II). Sodium azide inhibited Lac I (85%) and Lac II (75%) activities.