Salt-tolerant mechanism of marine Aspergillus niger cellulase cocktail and improvement of its activity  

作　　者：Linian Cai Shengnan Xu Tao Lu Dongqiang Lin Shanjing Yao 

机构地区：[1]Key Laboratory of Biomass Chemical Engineering of Ministry of Education,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China [2]College of Environment,Zhejiang University of Technology,Hangzhou 310014,China

出　　处：《Chinese Journal of Chemical Engineering》2020年第4期1120-1128,共9页中国化学工程学报（英文版）

基　　金：supported by National Natural Science Foundation of China(21576233,21878263);Fundamental Research Funds for the Central Universities。

摘　　要：The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.

关 键 词：Marine Aspergillus niger Cellulase component Directed expression SALT-TOLERANCE Cellulase activity 

分 类 号：TQ925[轻工技术与工程—发酵工程]