Interspecies and intersubstrate comparison of the biomass-degrading capacity of five filamentous fungi

The efficiency of microorganisms to degrade lignified plants is of great importance in Earth’s carbon cycle, but also in industrial biorefinery processes, such as for biofuel production. Here, we present a large-scale proteomics approach to investigate and compare the enzymatic response of five filamentous fungi when grown on five very different substrates: bagasse, birch, spruce, cellulose and glucose. The five fungi included the ascomycetes Aspergillus terreus, Hypocrea jecorina, Myceliophthora thermophila, Neurospora crassa and the white-rot basidiomycete Phanerochaete chrysosporium, all expressing a diverse repertoire of enzymes. Many studies have previously been performed with these fungi under various growth conditions, but this study is unique as it presents comparable quantitative protein abundance values across five filamentous fungi and five diverse substrates that allows for direct comparison of fungal response to the different substrates; this approach gives indications to substrate specificity of individual carbohydrate-active enzymes (CAZymes) and identifies several novel co-expressed non-CAZymes. Specifically, we present a quantitative comparison of 34 lytic polysaccharide monooxidenases (LPMOs), which are crucial enzymes in biomass deconstruction.