Fig. 2

Effects of pH and temperature on AmyZ1 activity (a, b) and stability (c, d). a Optimum pH of AmyZ1. With raw rice starch as the substrate, the optimum pH was determined in citrate–Na₂HPO₄ buffer (50 mM, pH 5.0–8.5) and Na₂HPO₄–KH₂PO₄ buffer (50 mM, pH 6.0–7.5). b Optimum temperature of AmyZ1. The assays were measured at temperatures from 20 to 70 °C in Na₂HPO₄–KH₂PO₄ buffer (50 mM, pH7.0). c Effect of pH on enzyme stability. The purified enzyme was incubated in 50 mM Na₂HPO₄–KH₂PO₄ buffer (pH 6.0–7.0) at 30 °C and the remaining activities were measured at appropriate intervals. d Effect of temperature on enzyme stability. The purified enzyme was incubated at 20–35 °C in Na₂HPO₄–KH₂PO₄ buffer (50 mM, pH 6.5). The remaining activities was determined at appropriate intervals. All the results were the average of triplicate experiments