黑曲霉A3菌株木聚糖酶粗酶制剂的制备和性质

本文研究了黑曲霉（AspergillusnigerA3）菌株固体发酵培养的产酶过程，发酵3d产木聚糖酶活最高，固体曲最适浸提比为1：7（W／V），通过60％～65％饱和度的硫酸按盐析，获得的木聚糖酶活力最高。冻干酶粉活力为15400u/g，得率为71％，40℃烘干酶粉活力为15395U／g，得率为51％，酶反应最适温度55℃，最适pH4．6，保温1h半失活温度（t1／2）为54℃，酶对四种不同底物半纤维素水解作用的亲合性为鼓皮最强，稻草最弱。

XYLANASE PREPARATION AND PROPERTIES FROM ASPERGILLUS NIGER

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.