Properties of An Aspergillus niger Producing Xylanase of Solid State Fermentation

Objectives:To selective breed Aspergillus niger for Xylanase production, and optimize it's culturing condition, study it's enzyme properties. Methods: Aspergillus niger producing Xylanase were picked out with transparence circle method. Effect of some factors as follows on enzyme production was studied: the ratio of corn cob to wheat bran, culturing temperature, culturing time, adding nitrogen sources. Effect of temperature, pH, metal ions on enzyme activity were tested. Enzyme stability in different temperature was tested.Results: An Aspergillus niger producing Xylanase was separated from nature soil. Cultivation conditions for the production of Xylanase in solid state were investigated. The Xylanase activity of the culture was 5500u/g dry koji. The optimal pH and temperature of the enzyme activity were 4.8 and 45℃. The activity of the enzyme was absent rapidly. above 45℃. The activity was activated by Mg~ 2+ and Zn 2+ and inhibited by Mn~ 2+ , Cu ~2+ and Hg~ 2+ . Conclusion: An Aspergillus niger producing Xylanase was screened. Its culture condition was simple.