We next investigated the biochemical characteristics of two functional laccase enzymes, Lacc6 and Lacc12. The oxidation activity of laccase was measured using various concentrations of ABTS. The activity increased proportionally to ABTS concentration, and became saturated at above 2 mM, showing maximum activities of 1,560 units/L and 600 units/L for Lacc6 and Lacc12, respectively, and Km values of 0.152 mM and 0.316 mM for Lacc6 and Lacc12, respectively (Fig. 5A). Vmax/Km, which represents the enzyme catalytic activity at low substrate concentration, was 10,263 units/L/mM and 1,898 units/L/mM for Lacc6 and Lacc12, respectively. These findings indicate that Lacc6 is 5.4-fold more active than Lacc12 at low substrate concentration. Both enzymes were highly active at acidic pH. Notably, Lacc6 showed lower pH optimum than Lacc12 with optimum pH values of < 3.0 and 3.5 for Lacc6 and Lacc12, respectively (Fig. 5B). The effects of temperature on laccase activity were also slightly different. Specifically, Lacc12 showed a 5oC higher temperature optimum than Lacc6; however, both enzymes were essentially thermophilic, with optimum temperatures of 45oC and 50oC for Lacc6 and Lacc12, respectively (Fig. 5C).