Study on the properties of xylanase from aspergillus niger

The properties of the xylanase from aspergillus niger were studied with spectrophotometer. The results show that the optimal temperature is 50℃ and optimal pH is 4.5 respectively, the range of pH stability is from 5.5 to 7.0, the enzyme is stable at 60℃,K~(+) and Cu~(2+) have inhibitory effect on the xylanase activity, but Co~(3+)、Ca~(2+)、Ba~(2+)、Zn~(2+)、Fe~(3+)、Mg~(2+) and Cr~(3+) could improve the activity, but Al~(3+) has no effect on the aylanase activity.