普鲁兰酶基因工程研究进展

普鲁兰酶是一类淀粉脱支酶，能够专一性地切开支链淀粉分支中的α-1，6-糖苷键，形成直链淀粉。普鲁兰酶能够与其他淀粉酶协同作用，主要应用在以淀粉为原料的食品加工中，大规模地提高了淀粉的利用率和生产效率。目前已获得的普鲁兰酶在大肠杆菌、芽胞杆菌以及毕赤酵母表达系统中均实现了表达，然而其表达水平难以满足工业生产的需要。着重从普鲁兰酶的异源表达及优化、酶蛋白分子改良方面对近几年普鲁兰酶最新的研究进展进行了综述，为寻找更有效提高表达量的途径提供理论基础。

Progress on Pullulanase Gene Engineering

As a starch debranching enzyme, pullulanase can specifically hydrolyze α-1,6 glucosidic linkages in polysaccharide and change amylopectin into amylose. Combinating with other amylases, pullulanase is mainly used in food processing industry taking starch as raw material. It can improve starch utilization rate and production efficiency by a large scale. At present, pullulanases have been expressed in E. coli, Bacillus sp. and Pichia pastoris expression system. However, these expression levels are hard to satisfy the requirement of industry production. This paper summarized the latest research progress made in recent years from the aspects of heterologous expression, optimization of pullulanase, and molecular modification of enzym protein, so as to lay a solid foundation for searching more effective way to improve pullulanase expression quantity.