Effect of temperature on enzyme stability. The enzyme was incubated at temperature ranged 20°C to 50°C in 100 mM pH 6.0 Na-acetate buffer for a period of time and residual activity was assayed in optimal temperature and pH by DNS method. Closed circles, rhombuses, triangles, and squares represent enzyme at 20°C, 30°C, 40°C, and 50°C. (a) Enzyme stability of AbnZ2. (b) Enzyme stability of AbnZ3.