Study on the Influential Factors of Xylanase Activity

The influential factors of xylanases (EC3.2.1.8) activity were studied. Optimum pH for both xylanase A and xylanase B wns 7.0, the optimum temperature for xylanase A and xylanase B was 65℃ and 70℃ respectively. The activity of both A and B enzyme was activited by Fe~(3+) at low concentration, but inhibited by Fe~(3+) at high concentration. Al~(3+) had inhibition on xylanase A, but a promoting effect on xylanase B. The activity of both xylanase A and xylanase B was inhibited by Cu~(2+). Mn~(2+) activated xylanase A, but inhibited xylanase B. Xylanase A had K_m of 5.57 mg/mL and V_(max) of 1.98×10~4μmol/ (mL· min ). The K_m and V_(max) for xylanase B were 6.09 mg/mL and 3.64×10~4 μmol/ (mL·min).