大米草半纤维素选择性酶解研究

采用由东方肉座菌EU7-22表达的重组木聚糖酶HoXyn11A、黑曲霉BE-2表达的重组木聚糖酶AnXyn10C和商品木聚糖酶分别降解大米草半纤维素,探索其降解的最佳工艺条件,结果发现该3种木聚糖酶最适pH值为4.5～5.5,最佳反应温度为45～55 ℃,酶用量为200～300 IU·g^-1底物,反应时间为12～24 h.对比结果表明:通过黑曲霉BE-2表达的重组木聚糖AnXyn10C能够在24 h内基本将大米草半纤维素降解为低聚木糖,效率远高于商品酶和东方肉座菌EU7-22表达的重组木聚糖酶HoXyn11A.黑曲霉BE-2表达的重组木聚糖AnXyn10C是大米草半纤维素降解酶的良好来源.

The Study on Selective Enzymatic Hydrolysis of Hemicellulose from Spartina anglica

The xylanase enzyme including xylanase HoXyn11A produced from Hypocreaorientalis EU7-2,xylanase AnXyn10C produced from Aspergillusniger BE-2 and commodity xylanase are respectively used to degrade hemicellulose of Spartina anglica.And its best condition of process is also explored.The result shows that the most suitable pH value of the 3 species enzyme is from 4.5 to 5.5,the best reaction temperature is from 45 ℃ to 55 ℃,the suitable enzyme dosage is 200 IU·g^-1 to 300 IU·g^-1 substrate,the best reaction time is 12 h to 24 h.The comparison results show that the recombinant xylan AnXyn10C expressed by aspergillus Niger b-2 can degrade hemicellulose into xylose oligosaccharide within 24 h,with a much higher efficiency than commercial enzymes and xylanase HoXyn11A produced from Hypocreaorientalis EU7-2.Hence,the recombinant xylan AnXyn10C expressed by Aspergillusniger BE-2 b-2 is an excellent source of enzymatic degradation of hemicellulose from Spartina anglica,which have great significance.