Fig. 1
From: Characterization and identification of the xylanolytic enzymes from Aspergillus fumigatus Z5
Properties of xylanases from A. fumigatus Z5. (a) Time course profile of xylanase production by A. fumigatus Z5 with the oat spelt xylan as the substrate. (b) Effect of temperature on xylanase activity of the crude enzyme. (c) Effect of temperature on xylanase activity of the purified endo-1,4-β-xylanase. (d) Effect of pH on the xylanase activity and pH stability of the crude enzyme. The enzyme was incubated at 50 °C for 10 min, with 1 % oat spelt xylan dissolved in citrate buffer (pH3.0, 4.0, 5.0 and 6.0), sodium phosphate buffer (pH6.0, 7.0 and 8.0), Tris–HCl buffer (pH8.0 and 9.0) or Glycine-NaOH buffer (pH9.0, 10.0 and 11.0). The brown line indicates the pH stability of the crude enzyme; the crude enzyme was pre-incubated without substrate in buffers of different pH for 1 h at 50 °C, and then the xylanase activity was measured under the standard conditions. (e) Effect of pH on the xylanase activity and pH stability of the purified endo-1,4-β-xylanase. (f) The thermal stability of the xylanase in the crude enzyme. The enzyme was incubated at pH 5.0 and at 20 °C (◇), 30 °C(◆), 40 °C(△), 50 °C(▲), 60 °C(□), 70 °C(■), 80 °C(○), or 90 °C(●). (g) The thermal stability of the purified endo-1,4-β-xylanase. (h) Kinetic curve of oat spelt xylan hydrolyzed by expressed endo-1,4-β-xylanase. The results are the mean of five replicates, and the bars indicate the standard error of three replicates