β-葡萄糖苷酶基因克隆及在丝状真菌中高效表达的研究进展

Research progress on β-glucosidase gene cloning and high level expression in filamentous fungi

纤维素酶是来源于真菌、细菌和原生动物并且能够降解纤维素成为葡萄糖单体的一组酶的总称,包括内切型(β-l,4)葡聚糖水解酶、外切型(β-1,4)葡聚糖水解酶、β-葡萄糖苷酶。β-葡萄糖苷酶能够水解纤维二糖产生两分子的葡萄糖,是纤维素酶的限速酶,但其含量少、活力低,成为纤维素酶解的瓶颈。因此,通过基因重组技术构建工程菌,开展关于β-葡萄糖苷酶基因高效表达的研究具有重要的意义。本文从β-葡萄糖苷酶及其菌株的筛选和育种、β-葡萄糖苷酶基因的克隆与表达、分泌及诱导等方面论述了如何使β-葡萄糖苷酶在丝状真菌中得到高效表达。

Cellulase is a group of several enzymes produced chiefly by fungi, bacteria, and protozoans which can catalyze cellulolysis, the decomposition of cellulose. It includes endo-1,4-beta-D-glucanase (beta-1, 4-glucanase, beta-1,4-endoglucan hydrolase, endoglucanase D, 1,4-(1,3,1,4)-beta-D-glucan 4-glucanohydrolase) andβ-glucosidase.β-glucosidase hydrolyzed cellobiose into 2 molecules of glucose which is the rate-limiting enzyme of cellulase. Moreover,β-glucosidase creates a bottleneck in cellulase hydrolysis owing to low content and poor enzyme activity. It is important to study the high level expression ofβ-glucosidase gene by construct-ing of engineering bacteria using gene recombination technology. Herein, we review the current progress of studies on the strain screening and breeding,β-glucosidase gene cloning, secretion and induction, and high lev-el expression in filamentous fungi.