Laccase forms ( L1 and L2) from Trametes versicolor CCT 4521 showed a molecular mass of 66 kDa and optimum temperature around 40 degrees C. The optimum pH ( 4.0 and 5.0) and K-m ( 28.6 and 5 mu M) values using syringaldazine as substrate were found for L1 and L2, respectively. The enzymes were able to oxidize several compounds and were strongly inhibited by sodium azide, L-cysteine and dithiothreitol. The 75% of the N-terminal sequences were identical in both forms and similarities around 40-60% of laccases from wood-degrading fungi were observed. The use of 1-hydroxybenzotriazole as a mediator increased the compounds oxidized by laccases in olive mill wastewater.61012481254