Characterization of recombinant HhXyl. (A) The effect of pH on the activity of HhXyL. (B) The effect of temperature on the activity of HhXyl. (C) The thermostability of HhXyl determined at different temperatures. The enzyme was incubated in the absence of of substrate for 10, 20, 30, 60 and 120 min before measuring its activity. Xylanase activity prior to pre-incubation was considered 100%.