耐热子囊菌产木聚糖酶及酶学性质的研究

对 1株耐热子囊菌 (Thermoascusaurantiacus)固态发酵产木聚糖酶的工艺条件及酶学性质进行了研究。确立了适宜的产酶基质为 :麸皮 3 0 %、玉米芯 3 5 %、玉米皮 3 5 %、(NH4 ) 2 SO4 2 %、尿素 0 5 %、KH2 PO4 0 5 %、MgSO4 ·7H2 O 0 2 %、初始含水量 65～ 70 %。 45℃培养 5d ,木聚糖酶活力最高可达 1 0 3 2 1IU/g(干曲 )。该木聚糖酶最适反应温度为 70℃ ,最适pH4 8;在 pH3 0～ 7 0 ,温度低于 65℃时稳定性能较好。可被Fe2 +、Mg2 +、Zn2 +激活 ,而被Co2 +、Fe3+、Mn2 +抑制。

Study on Production and Property of Xylanase by Thermoascus aurantiacus Using Solid State Fermentation

Xylanase production by Thermoascus aurantiacus was studied under solid state fermentation process. The culture substrate was optimized as follows:wheat bran 30%, corncob 35%, corn husk 35%, (NH_4)_2SO_4 2%, carbamide 0.5%. The initial moisture content 65%～70%. Xylanase activity reached 10 321?IU/g koji after 5days at 45℃. Study on the enzyme properties showed that the optimal pH value and temperature were 4.8 and 70°C, respectively. The enzyme was stable under 65℃,pH 3.0～7.0. Fe 2+,Mg 2+,Zn 2+ take various stimulus roles to xylanase activity, whereas Co 2+,Fe 3+, Mn 2+ inhibit xylanase activity. The enzyme has been widely applied in feeding, food, paper pulp, textile industries and the bioconversion of hemicelluloses.