Improved secretory expression and characterization of thermostable xylanase and β-xylosidase from Pseudothermotoga thermarum and their application in synergistic degradation of lignocellulose

Frontiers in Bioengineering and Biotechnology

Bioengineering and Biotechnology

Hao Qin¹  Chaoqun You²  Lingfeng Long³  Jinkang Chen³ 

[1] Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, China;Little Swan Electric Co., Ltd., Midea Group, Wuxi, China;Jiangsu Key Lab for the Chemistry and Utilization of Agro-Forest Biomas, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China;Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China;

关键词: xylanase;    xylosidase;    secretory expression;    molecular docking;    saccharification;   

DOI  :  10.3389/fbioe.2023.1270805

 received in 2023-08-01, accepted in 2023-09-04,  发布年份 2023

来源: Frontiers

【 摘 要 】

Xylanase and β-xylosidase are the key enzymes for hemicellulose hydrolysis. To further improve hydrolysis efficacy, high temperature hydrolysis with thermostable hemicellulases showed promise. In this study, thermostable xylanase (Xyn) and β-xylosidase (XynB) genes from Pseudothermotoga thermarum were cloned and secretory expressed in Bacillu subtilis. Compared with Escherichia coli expression host, B. subtilis resulted in a 1.5 time increase of enzymatic activity for both recombinant enzymes. The optimal temperature and pH were 95°C and 6.5 for Xyn, and 95°C and 6.0 for XynB. Thermostability of both recombinant enzymes was observed between the temperature range of 75–85°C. Molecular docking analysis through AutoDock showed the involvement of Glu525, Asn526, Trp774 and Arg784 in Xyn-ligand interaction, and Val237, Lys238, Val761 and Asn76 in XynB-ligand interaction, respectively. The recombinant Xyn and XynB exhibited synergistic hydrolysis of beechwood xylan and pretreated lignocellulose, where Xyn and XynB pre-hydrolysis achieved a better improvement of pretreated lignocellulose hydrolysis by commercial cellulase. The observed stability of the enzymes at high temperature and the synergistic effect on lignocellulosic substrates suggested possible application of these enzymes in the field of saccharification process.

【 授权许可】

Unknown   
Copyright © 2023 Chen, Qin, You and Long.