Enzymatic assays
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