This interdisciplinary project investigates the enzymatic mechanism underlying fungal degradation of complex carbohydrates in plant biomass.

As efficient degraders of dead plant biomass, fungi are able to produce enzymes that can break down the complex of polysaccharides and lignin in the plant cell wall. This ability is exploited in biotechnology to release sugars from renewable resources which are subsequently used to produce high-value chemicals and second-generation biofuels. Understanding how fungi degrade biomass is a prerequisite for their exploitation as cell factory for biofuel enzymes, and for development of novel enzymes for the engineering of complex plant-derived carbohydrates. The response of industrially important fungi to lignocellulose has been studied extensively with regard to gene expression and protein secretion (1,2). However, we have limited understanding of how fungi and their carbohydrate-active enzymes (CAZymes) affect the actual lignocellulose substrate, and the biochemical activity of a large proportion of plant degradative CAZymes has not been established experimentally.

This project investigates the enzymatic mechanism underlying fungal degradation of complex carbohydrates in plant biomass. We have recently established methods for the high-throughput informative screening of CAZyme activities on complex plant carbohydrates using glycan arrays coupled with mass spectrometry (3). In this project you will expand on these methods by using a combination of chemical and enzymatic synthesis to generate glycan arrays containing a defined set of enzyme substrates. These arrays will subsequently be applied to determine the substrate and product specificity of a subset of the CAZymes secreted by fungus Aspergillus niger during growth on agricultural waste. You will then investigate the localisation and effect of these enzymes on this plant substrate using fungal biology, molecular biology and surface characterisation tools.