Fig. 3

Effect of temperature, pH, and NaCl on MtCh509. a Optimal temperature (solid circles) and thermostability (open circles) of MtCh509 under preincubation for 30 min. b Further thermostability of MtCh509 preincubated at 40 °C (open circles), 50 °C (open squares), and 55 °C (open diamonds) for 1–4 h. c Optimal pH (solid) and pH stability (open) of MtCh509. Reactions were performed in the following 50 mM buffers: citrate buffer for pH 3.0–6.0 (circles), sodium phosphate buffer for pH 6.0–8.0 (squares), Tris–HCl buffer for pH 8.0–9.0 (diamonds), and glycine–NaOH buffer for pH 9.0–10.0 (triangles). The means of the relative values (n = 3) and standard deviations are shown