Available online 18 May 2022

The P. subrubescens genome harbors an expanded set of genes encoding endoxylanases

P. subrubescens endoxylanases (PsXLNs) are xylan-specific and base-tolerant

PsXLNs display a diverse hydrolysis pattern and 3D-structure

The diversity amongst PsXLNs is attractive for various biotechnology applications

Penicillium subrubescens has an expanded set of genes encoding putative endoxylanases (PsXLNs) compared to most other Penicillia and other fungi. In this study, all GH10 and GH11 PsXLNs were produced heterologously in Pichia pastoris and characterized. They were active towards beech wood xylan (BWX) and wheat flour arabinoxylan (WAX), and showed stability over a wide pH range. Additionally, PsXLNs released distinct oligosaccharides from WAX, and showed significant cooperative action with P. subrubescens α-L-arabinofuranosidases (PsABFs) from GH51 or GH54 for WAX degradation, giving insight into a more diverse XLN and ABF system for the efficient degradation of complex hemicelluloses. Homology modelling analysis pointed out differences in the catalytic center of PsXLNs, which are discussed in view of the different modes of action observed. These findings facilitate understanding of structural requirements for substrate recognition to contribute to recombinant XLN engineering for biotechnological applications.

Carbohydrate-Active enZyme

α-L-arabinofuranosidases

wheat flour arabinoxylan

P. subrubescens XLNs

P. subrubescens ABFs

Molecular Evolutionary Genetic Analysis

3,5-dinitrosalicylic acid

High Performance Size-Exclusion Chromatography with Refractive Index detection

High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detection

carbohydrate-binding module

degree of polymerization

Penicillium subrubescens

gene expansion

xylan degradation

functional diversity

structural diversity

© 2022 The Author(s). Published by Elsevier B.V.