Oxidative enzymes during decolorization The oxidative enzymes were assayed spectrophotometrically in the cell free extract. Laccase activity was determined in a reaction mixture of 2 ml containing 10% ABTS in 20 mM potassium
phosphate buffer (pH 4.0) and increase in the optical density was measured at 420 nm. Molar extinction coefficient of ABTS was 0.036 mM/cm at 420 nm (21).