Both enzymes were stable at 40°C (Fig. 5), i.e. Xyl I retained 71% and
Xyl II retained 77.5% of the activity after 4.5 h of incubation. Xyl I
exhibited half-life of 4 min at 50°C and of 40 s at 60°C, while the
half-life of Xyl II was 18 min at 50°C and 46 s at 60°C. The purified
Trichoderma sp. K9301 xylanase was very stable at 50°C but also
rapidly lost activity when incubated at 60°C [15].