中文摘要：

极耐热纤维素酶在纤维素生物转化中具有潜在的开发前景，但极耐热酶缺乏对天然纤维素的分解能力。采用基因工程方法，将极耐热内切葡聚糖酶Cel12B基因和同样极端嗜热菌来源的纤维素结合域（CBD）区域融合，构建重组质粒pET-20b—Cel12B-CBD，转化至大肠杆菌JN109（DE3）诱导表达后，融合基因表达产物对结晶纤维素具有一定的分解能力。

英文摘要：

The endoglucanase found in Thermotoga maritima showed extremely high thermostability and considerable potential in industrial application of enzymatic hydrolysis of cellulose. Endoglucanase （Tm） Cel12B is extracellular enzyme. Tm Cel12B did not contain a cellulose-binding domain（CBD）and lacked activity on crystalline cellulose. Tm XynA is composed of catalytic domain（CD） and cellulose-binding domain（CBD）. As such, the gene of CBD from Tm XynA was fused at the carboxyl-terminus of Tm Cel12B and recombinant plas- mid pET-20b-Cel12B-CBD was obtained. The chimera enzyme was expressed in Escherichia coli and activities were displayed on crystalline cellulose.