【摘要】 葡萄糖苷酶（BGL）是催化纤维素产生葡萄糖过程中的关键酶,在生物能源利用和食品领域发挥重要作用.本研究克隆了来源于Thermoplasma volcanium的β-葡萄糖苷酶（BGL）基因,并在大肠杆菌中进行表达,经纯化获得了Tv-BGL.酶学性质分析发现,Tv-BGL在pH6.0和80℃时发挥最佳催化活力,以对硝基苯基-β-D-吡喃葡萄糖苷（pNPGlu）为底物时的K_m和V_max分别为0.725 4mmol/L和614.60U/mg,Kcat/K_m=7.79×105 mol^-1·L·s^-1,以纤维二糖（Cellobiose）为底物时的K_m和V_max分别为55.63mmol/L和636.06U/mg,Kcat/K_m=1.06×104 mol^-1·L·s^-1.另外,该酶具有较好的热稳定性,有机溶剂、离子以及葡萄糖耐受性.更多还原

【Abstract】 Glucosidase（BGL）is a critical enzyme in the process of catalyzing the production of glucose from cellulose and plays an essential role in the use of bioenergy and food.In this study,theβ-glucosidase（BGL）gene derived from Thermoplasma volcanium was cloned and expressed in E.coli,and protein was obtained after purification.The analysis of enzymatic properties found that Tv-BGL exerts the highest catalytic activity at pH 6.0 and 80℃．The K_mand V_max with substrate p-nitrophenyl-β-D-glucopyranoside（pNPGlu）are 0.725 4 mmol/L and614.60 U/mg,respectively,and the enzyme has Kcat/K_m= 7.79×105 mol^-1·L·s^-1,K_mand V_max when using Cellobiose as the substrate are 55.63 mmol/L and 636.06 U/mg,respectively,Kcat/K_m=1.06×104 mol^-1·L·s^-1.In addition,the enzyme has good thermal stability,organic solvent tolerance,ion tolerance,and glucose tolerance,which are beneficial to industrial applications.更多还原