Purification and some properties of fungal Xylanase

Partial purification of xylanase produced by Aspergillus niger strain AUMC 14230 is carried out with 80% saturation of ammonium sulfate under pH5.0 as first step. The second step in partial purification is Acetone 2.5/1 (v/v). The last step is gill filtrations which give the highest specific from both enzymes. Many factors affecting on purified enzymes. The best activity of xylanase was produced till 72 hrs and decreased by (8.8% & 10.9%), respectively after 72 hrs. Xylan (1mg) concentration was the best substrate to produce relative activity 100% for xylanase enzyme. We found that the glucose has an inhibitory effect on both enzymes activity. Optimum temperature for xylanase is 50oC, increased temperature decreased productivity of both enzymes. The addition of Ca2+, Ba2+, Mg2+ and EDTA strongly enhanced both xylanase activity, While, Co2+ and Ag+ decreased the productivity. On the other hand, the Fe2+, Cu2+ and Mn2+ showed moderate inhibition.