XYLANASE PREPARATION AND PROPERTIES FROM ASPERGILLUS NIGER
黑曲霉A3菌株木聚糖酶粗酶制剂的制备和性质

The production process of xylanase of solid-state fermentation from Aspergillus nigerwas studied. The maximum enzyme activity can be obtained when the fungus wat cultured for 3days. The ratio between the solid culture and the extracting agent was about 1:7(w / v). Thesaturation condition of (NH4)2SO4 is the range from 6O%~65%. Two kinds of xylanase enzymepowder were obtained by both freezer drying and at 40C heating drying, and the rate of recovery71% and 51% were respectively. The highest xylanase activity has about l5400u / g by freeerdrying, 15395u / g by heating drying. The related properties of enzyme were analysed. the optimaltemperature is 55t and pH is 4.6. Th tempetatUre for 1oss half achvity(t l / 2) in a hour is 54t.Among the four kinds of hemicellulose, the strongest and the weakest hydrolytic affinity ofxylanase are wheat bran and rice straw respectively.