Progress in Enzymatic Production of Trehalose

Trehalose is a non-reducing disaccharide, and widespread in nature. It is a typical stress metabolite that can protect macromolecules such as proteins in organisms under extreme conditions. Therefore, trehalose has been widely used in food, medicine and cosmetics. Trehalose is extracted from yeast or synthesized by chemical method. Due to the high cost of traditional methods, trehalose is mainly produced by enzymatic methods. There are mainly three pathways: TPS/TPP, TreY/TreZ and TreS. These enzymatic systems are expressed mainly through heterologous expression.

葡萄糖氧化酶在枯草芽孢杆菌芽孢表面的展示及其酶电极制备

葡萄糖生物传感器是目前最为常见的电化学生物传感器,绝大多数葡萄糖生物传感器采用在电极表面修饰葡萄糖氧化酶的方法来制备,但是,在电极的固定化过程中需要酶的纯化,使得成本增加,已成为固定化酶电极开发领域的瓶颈。文中主要以芽孢衣壳蛋白CotX为锚定蛋白将葡萄糖氧化酶(Glucose oxidase,GOD)展示到枯草芽孢杆菌芽孢表面,通过Western blotting分析、免疫荧光分析以及酶活检测均证明GOD在芽孢表面有效表达,发酵获得重组芽孢(Spore-GOD)。再采用滴涂法和电沉积法制备了氧化石墨烯/普鲁士蓝沉积膜修饰玻碳电极,将Spore-GOD固定在修饰电极表面,最后滴加一层Nafion溶液,制成了电化学生物传感器,用于葡萄糖的灵敏测定。葡萄糖在该酶电极传感器上的循环伏安图表明,该反应在0.42V处出现明显的氧化峰,并且氧化还原峰电流与葡萄糖浓度在0.1–7.0mmol/L之间具有良好的线性关系,校正曲线方程为:I=1.3047Cglucose+3.639(R2=0.9929),其检测限为7.5μmol/L(S/N=3)。此修饰电极具有良好的导电性能、稳定性和重现性,可用于葡萄糖的分析测定。