Fig. 2.

Effects of O₂ limitation and catalase addition on CTec3 cellulose hydrolysis progress curves. Pretreated wheat straw was incubated with 2.8 (blue circles), 5.6 (red triangles), 8.4 (green squares) and 11.2 mg protein/g cellulose (black diamonds) of CTec3 for 144 h at 50 °C, pH 5. Reactions were carried out in ambient air (panels a and c) and O₂-deprived (panels e and g) conditions. Similarly, the effects of adding catalase under each of these conditions are shown in panels c and g, respectively. To better illustrate time-dependent enzyme inactivation under each of these conditions, the conversion data are plotted as a function of enzyme dose x time in panels b, d, f and h. Model fits to these data are shown by lines colour-matched to the data