Heterologous expression and functional characterization of a GH10 endoxylanase from Aspergillus fumigatus var. niveus with potential biotechnological application

Authors

Josman Velasco, University of Sao Paulo, Brazil
Bianca Oliva, University of Sao Paulo, Brazil
Evandro Jose Mulinari, University of Sao Paulo, Brazil
Leidy Patricia Quintero, University of Sao Paulo, Brazil
Awana da Silva Lima, University of Sao Paulo, Brazil
Aline Larissa Goncalves, University of Sao Paulo, Brazil
Thiago Augusto Goncalves, University of Campinas, Brazil
Andre Damasio, University of Campinas, Brazil
Fabio Marcio Squina, University of Campinas, Brazil
Adriane Maria Ferreira Milagres, University of Sao Paulo, Brazil
Asmaa Abdella, University of Nebraska - Lincoln
Mark R. Wilkins, University of Nebraska - LincolnFollow
Fernando Segato, University of Sao Paulo, BrazilFollow

Document Type

Article

Date of this Version

2019

Citation

Biotechnology Reports 24 (2019) e00382

Comments

© 2019 The Authors.

Open access

https://doi.org/10.1016/j.btre.2019.e00382

Abstract

Xylanases decrease the xylan content in pretreated biomass releasing it from hemicellulose, thus improving the accessibility of cellulose for cellulases. In this work, an endo-β-1,4-xylanase from Aspergillus fumigatus var. niveus (AFUMN-GH10) was successfully expressed. The structural analysis and biochemical characterization showed this AFUMN-GH10 does not contain a carbohydrate-binding module. The enzyme retained its activity in a pH range from 4.5 to 7.0, with an optimal temperature at 60°C. AFUMN-GH10 showed the highest activity in beechwood xylan. The mode of action of AFUMNGH10 was investigated by hydrolysis of APTS-labeled xylohexaose, which resulted in xylotriose and xylobiose as the main products. AFUMN-GH10 released 27% of residual xylan from hydrothermally-pretreated corn stover and 14% of residual xylan from hydrothermally-pretreated sugarcane bagasse. The results showed that environmentally friendly pretreatment followed by enzymatic hydrolysis with AFUMN-GH10 in low concentration is a suitable method to remove part of residual and recalcitrant hemicellulose from biomass.