Figure 3

Optimal pH of mutant enzymes compared to the native CTendo45. The optimal pH value for each endoglucanase activity was assayed in 50 mM buffer solutions over a pH range from 3 to 9, including acetate buffer (pH 3–6), sodium phosphate buffer (pH 6–8) and Tris-HCl buffer (pH 8–9). The reaction was incubated at 60 °C for 30 min using 1% (w/v) CMC-Na as the substrate. The highest activity was defined as 100%. Values are the means ± SD of three replicates.