Fig. 3. Effects of various (A) temperatures and (B) pH values on wild-type and mutant phytase activity. The activity was measured using 1 mM sodium phytate as a substrate in the presence of 4 mM CaCl2. Relative activity was expressed based on the activity of the wild-type under optimal conditions (40°C, pH 6). Significant differences (p < 0.05) in enzymatic activity were observed only in mutant E263A.