片烟黑曲霉菌株产纤维素酶的条件优化及酶的分离纯化

为降低烟叶燃吸的刺激味、改善口感、增加香气、提高烟叶品质，从烟叶表面筛选到一株产纤维素酶活性较高的黑曲霉，应用Plackett Burman试验确定4种显著因子，RSM法对4种显著因子进行了优化和分析，并对酶蛋白的分离纯化作了初步研究。结果显示：发酵产酶的最适碳源为玉米芯，氮源为NH4NO3，当玉米芯用量为13.4%，NH4NO3为0.4%，温度为30.4℃，pH为5.6时产酶比活力最高，可达40.02 U·mL-1。纤维素酶酶蛋白的硫酸铵盐析最佳饱和度为60%，经Sephadex G100凝胶柱层析纯化后的比活力提高了3.5倍，回收率为32.6%，达到较高水平。

Optimization of cellulase production by Aspergillus niger separated from tobacco and its separation and purification

In order to improve tobacco taste， decrease the smoking pungent taste， increase the fragrance and improve the smoking quality， a mold strain Aspergillus niger possessing relatively higher cellulase enzymatic activity was isolated from tobacco leaves The Plackett Burman design was used to choose the most important factors， then， these factors were optimized by RSM method， and the purification of enzyme was investigated The results indicated that the optimum carbon source and nitrogen source were 1.4% corn cob and 0.4% NH4NO3， the optimum original pH was 5.6 and the optimum cultural temperature was 30.4℃ Under these conditions， the specific enzyme activity was 40.02 U·mL-1 The crude cellulase was isolated and purified by means of ammonium sulfate precipitation， followed by chromatography on Sephadex G100 The specific activity of the cellulase increased to 3.5 fold of the source enzyme with an activity recovery of 32.6%.