Fig. 1

ApV1 shows improved thermostability at 65, 75 or 85 °C. Diagram of AppA phytase amino acid sequence indicating cysteine residues forming disulfide bonds and residue mutations in ApV1 (L28C, W360C) (a). ApV1 structure indicating disulfide bonds (in red) and active site residues (in yellow) (b). ApV1 and AppA thermostability curves at 65, 75 or 85 °C (c). Phytase activity was determined by the p-NPP assay after incubation at 65, 75 or 85 °C. Remaining activity was calculated as a percentage of the observed phytase activity with no incubation. All assays were performed at 37 °C. Data are represented as mean values ± standard deviation (n = 3)