The aim of this work is to study a bifunctional endoglucanase/carboxylesterase in Sphingobacterium soilsilvae Em02 and express it in soluble form in engineered Escherichia coli. The molecular weight of the recombinant protein of the bifunctional enzyme was 41 KDa. This research also determined the enzymatic activities of the bifunctional enzymes using microcrystalline cellulose and p-nitrophenyl butyrate as substrates and found 40 °C as the optimum temperature for their enzymatic activities. The optimal pH in dual function was 6.0 for endoglucanase and 7.0 for carboxylesterase. The bifunctional enzyme also exhibited enzymatic activities on the natural biomass by generating up to 3.94 mg of glucose and 49.4 μg of ferulic acid from 20 mg of destarched wheat bran. This indicates the broad application prospects of the bifunctional enzyme in agriculture and industry.

这项工作的目的是研究Sphingobacterium soilsilvae Em02中的双功能内切葡聚糖酶/羧酸酯酶，并在工程大肠杆菌中以可溶形式表达它. 双功能酶重组蛋白的分子量为41 KDa。本研究还测定了以微晶纤维素和丁酸对硝基苯酯为底物的双功能酶的酶活性，发现 40 °C 是其酶活性的最适温度。双重功能的最佳 pH 值对于内切葡聚糖酶为 6.0，对于羧酸酯酶为 7.0。双功能酶还通过从 20 毫克脱淀粉麦麸中产生高达 3.94 毫克葡萄糖和 49.4 微克阿魏酸，对天然生物质表现出酶促活性。这预示着双功能酶在农业和工业中的广阔应用前景。