Possible targets of wood modification in brown rot degradation
R Ringman, A Pilgård, G Alfredsen, B Goodell, K Richter
Wood modification protects wood from fungal degradation in a non-toxic manner. However, the mechanisms behind the decay resistance in modified wood are currently unknown. The aim of this study was to discuss the i) colonisation, ii) nutrient recognition, iii) transcription, iv) depolymerisation and v) hydrolysis steps in the brown rot degradation progress and explore whether they are inhibited by wood modification, based on new and previously published data from our group. In previous studies, it has been shown that fungi were able to colonise modified wood, to recognise it as a source of nutrients and express genes associated with cellulose degradation while growing on modified wood. In this study, Fenton derived hydroxyl radicals (∙OH) and brown rot cellulases were able to degrade modified wood. We conclude that the five degradation steps discussed in this paper are unlikely targets for wood modification and that wood modification rather inhibits a step that in a schematic overview of the brown rot degradation process is downstream from transcription but upstream of depolymerisation and hydrolysis.