To determine the profiles of ligninolytic enzymes,enzymeassays
were conducted for laccase, lignin peroxidase (LiP) and manganese
peroxidase (MnP) at the end of each experiment (except for screening)
from the decolorization culture filtrates. Laccase activity was
measured by method of Shin and Lee [24] by monitoring 2,2 azinobis
thiazoline-6 sulphonate (ABTS) oxidation. One unit of laccase
activity was defined as the amount of enzyme required to produce
a unit increase in absorbance per mL per min of the reaction mixture.
MnPwas assayed by the method ofWariishi et al. [25]. MnSO4
was added to sodium melonate buffer in the presence of H2O2. The
complex formed between Mn2+ and melonate absorbs at 270 nm.
MnP activity (U/mL)was defined as the amount of enzyme producing
one unit increase in absorbance per mL per min of the reaction
mixture. Lignin peroxidase activity was determined by following
the method of Tien and Kirk [26]. The oxidation rate of veratryl
alcohol to veratraldehyde was followed at 310nm in sodium succinate
buffer (pH 3) in the presence of H2O2 for 10 min. One unit of
LiP activity was defined as the amount of enzyme required to catalyze
the formation of 1mol of veratraldehyde per minute under
the reaction conditions.