Figure 3.

Response surface curve for the effects of pH and temperature on laccase activity (a), and thermal stability of the purified Lacps1 (b). In thermal stability studies (b), samples of the purified laccase in water were incubated at 55 °C (□), 60 °C (●), 65 °C (▲), 70 °C (O) or 75 °C (■), and the residual activities were determined at 65 °C in McIlvaine buffer, pH 4.5, containing 1.0 mmol·L⁻¹ ABTS. One hundred percent specific activity corresponded to 401.4 ± 17.9 U·mg⁻¹. The values presented correspond to means ± SD from triplicate experiments (n = 3) performed with three separate preparations of pure Lacps1.