右旋糖酐酶结构、性质及其应用研究进展

右旋糖酐酶(dextranase)能够专一性地水解右旋糖酐中的α-1,6糖苷键，降低蔗汁的粘度、防止仪器堵塞、增加目标产品的回收率和质量。右旋糖酐酶在降解右旋糖酐的同时生成异麦芽糖、异麦芽三糖等低聚糖，这些低聚糖不被人体消化吸收可直接进入大肠选择性地增殖双歧杆菌等有益菌，有润肠通便、促进矿物质元素吸收、增强免疫力等功效。文章结合国内外相关研究进展，对右旋糖酐酶的结构、右旋糖酐酶生产菌株、右旋糖酐酶酶活及酶学性质改进技术进行综述，发现传统诱变技术和发酵条件的优化可以在一定程度上提高右旋糖酐酶的发酵水平，通过构建基因工程菌，可有效提高右旋糖酐酶的异源表达水平，结合酶固定化技术提高酶在不利条件下的稳定性和回收率，在低聚糖制备及制糖工业中有广泛的应用前景。本文为后期右旋糖酐酶的研究方向提供一定的参考。

Research Progress on the Structure,Properties and Application of Dextranase

Dextranase can specifically hydrolyze the α-1,6 glycosidic bond in dextran, reduce the viscosity of sugarcane juice, prevent the blockage of the instrument, and increase the recovery and quality of the target product. Dextranase degrades dextran and produces oligosaccharides such as isomaltose and isomaltotriose. These oligosaccharides are not digested and absorbed by human body, which can directly enter the large intestine and selectively proliferate beneficial bacteria such as Bifidobacterium. They have the effects of moistening intestine, promoting the absorption of mineral elements and enhancing immunity. Based on the research progress at home and abroad, the article reviews the structure of dextranase, dextranase production strains, dextranase enzyme activity and improvement technology of enzymatic properties. It is found that traditional mutagenesis technology and optimization of fermentation conditions can improve dextranase to a certain extent. Through the construction of genetically engineered bacteria, the heterologous expression level of dextranase can be effectively improved, combined with enzyme immobilization technology to improve the stability and recovery rate of the enzyme under unfavorable conditions. It is widely used in oligosaccharide preparation and sugar industry. This paper provides a reference for the research direction of late dextranase.