1 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands.
2 Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.
3 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands; Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada; Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, the Netherlands.
4 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands; Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, the Netherlands.
5 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands; Department of Microbiology, P.O. Box 56, Viikinkaari 9, University of Helsinki, Helsinki, Finland.
6 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands; Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, the Netherlands. Electronic address: r.devries@westerdijkinstitute.nl.

The presence of trace components significantly broadens the molecular response of Aspergillus niger to guar gum.

N Biotechnol. 2019 Jul 25;51:57-66

Authors: Coconi Linares N, Di Falco M, Benoit-Gelber I, Gruben BS, Peng M, Tsang A, Mäkelä MR, de Vries RP

Abstract

Guar gum consists mainly of galactomannan and constitutes the endosperm of guar seeds that acts as a reserve polysaccharide for germination. Due to its molecular structure and physical properties, this biopolymer has been considered as one of the most important and widely used gums in industry. However, for many of these applications this (hemi-)cellulosic structure needs to be modified or (partially) depolymerized in order to customize and improve its physicochemical properties. In this study, transcriptome, exoproteome and enzyme activity analyses were employed to decipher the complete enzymatic arsenal for guar gum depolymerization by Aspergillus niger. This multi-omic analysis revealed a set of 46 genes encoding carbohydrate-active enzymes (CAZymes) responding to the presence of guar gum, including CAZymes not only with preferred activity towards galactomannan, but also towards (arabino-)xylan, cellulose, starch and pectin, likely due to trace components in guar gum. This demonstrates that the purity of substrates has a strong effect on the resulting enzyme mixture produced by A. niger and probably by other fungi as well, which has significant implications for the commercial production of fungal enzyme cocktails.

PMID: 30797054 [PubMed - indexed for MEDLINE]