Fig 4. Effect of temperature on the activity and stability of the purified laccase.

(a) Optimal temperature (open circles) was determined at pH 7.5 by using guaiacol as the substrate. Residual activity (closed circles) was determined after incubation at 40°C–90°C for 1 h. (b) Residual activity was determined after incubation at 70°C, 80°C, and 90°C, respectively, for 0–4 h. The graphs display the average values from triplicate measurements. The error bars represent the standard deviation.