Delignification abilities of the white-rot fungus Polyporus brumalis explained by its oxidative enzymatic arsenal

The fungus Polyporus brumalis is a wood decay fungus previously evidenced as efficient lignin degrader with high potential for plant biomass pre-treatment before conversion into bio-energy. Here we used an RNASeq approach that highlighted the active transcription of an unparalleled number of lignin active peroxidases and H2O2 generating enzymes during growth on wheat straw. These enzymes, together with metabolic processes related to detoxification appear as key determinants of the fungal adaption to lignin degradation. To identify the enzymatic determinants responsible for the observed selective degradation of lignin, we compared the transcription profiles of P. brumalis after 10-day growth on 2% malt extract (control) with the transcription profiles after 6-days growth on 2% malt extract followed by 4, 10 and 15 days fermentation on wheat straw.