Assays for laccase activity were pe

Assays for laccase activity were performed using ABTS as substrate,
with the oxidation of the ABTS being monitored by measuring
the absorbance at 420 nm (e420 = 3.6  104 M1 cm1
). The
reaction mixture contained 30 ll of the appropriately diluted test
enzyme preparation and 270 ll of 1 mM ABTS in 0.1 M sodium
acetate buffer pH 3.0 at 30 C. One unit (U) of enzyme activity
was defined as the amount of enzyme that oxidizes 1 lmol of ABTS
per min, and the activity was expressed in U ml1