Effects of mutations on the residual activities of the A. fumigatus Afp (A to C) and A. niger PhyA (D to F) phytases after being heated to various temperatures for 10 min. (A) WT (+), E35A (⋄), R168A (▵), and R248A (*). (B) WT (+), E35A R168A (×), E35A R248A(□), and R168A R248A(♦). (C) WT (+) and E35A R168A R248A (○). (D) WT (⋄), A58E Q191R (□), and A58E P65S (×). (E) WT (⋄) and A58E Q191R T271R (▵). (F) WT (⋄) and A58E P65S Q191R T271R (○). An asterisk indicates a difference (P < 0.05) between the residual activities of the respective WT protein and the mutants.