THE CONSTRUCTION OF BIFUNCTIONAL FUSION XYLANOLYTIC ENZYMES AND THE PREDICTION OF OPTIMUM REACTION CONDITIONS FOR THE ENZYME ACTIVITY

Cheng-Kang Pai, Han-Tsung Wang, Rey-Ting Guo, Je-Ruei Liu

Abstract


Four chimeric xylanolytic enzymes were formed by fusion of a thermally stable xylanase XynCDBFV either to the N-terminus or C-terminus of a thermally stable acetylxylan esterase AxeS20E, with or without a Gly-rich flexible linker (S2). The three-dimensional (3D) structures of the chimeric enzymes were predicted using the I-TASSER server, and the results indicated that the structures of Axe-S2-Xyn and Xyn-S2-Axe were more similar to the native structures than were those of Axe-Xyn and Xyn-Axe. Axe-S2-Xyn and Xyn-S2-Axe were expressed in Escherichia coli and purified by means of affinity chromatography. Response surface modeling (RSM), combined with central composite design (CCD) and regression analysis, was then employed to optimize the xylanase activities of the chimeric enzymes. Under the optimal conditions, Xyn-S2-Axe had greater hydrolytic activities on natural xylans and rice straw than did the parental enzymes. These results suggested that the chimeric enzyme Xyn-S2-Axe could be effective at hydrolyzing xylan in biomass and that it has potential to be used in a range of biotechnological applications.

Keywords


Chimeric enzyme; Neocallimastix patriciarum; Xylanase; Acetylxylan esterase

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126