Characterization of the degradation patterns of chemically modified wood by wood-destructive basidiomycetes

Novel chemical wood modification processes aim to improve both the elasto-mechanical properties and durability of wood. One of the most promising methods is the treatment with 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU). In fungal tests according to EN 113 (durability against basidiomycetes) and ENV 807 (durability in soil contact; rot), a significant increase in the durability of treated wood could be proven on the basis of mass loss.
To date, the exact causes of the protective effect of chemical modification are yet to be deeply investigated. The aim of this project is to characterize the degradation mechanisms by which wood-destructive basidiomycetes degrade wood modified by (DMDHEU). These degradation mechanisms are compared with those of untreated wood.
Two typical representatives of white and brown rot causing fungi are investigated using microscopic, spectroscopic and biochemical techniques.
First, the changes in the cell wall caused by the fungus is determined using various microscopic methods. These changes are then characterized more precisely by chemical and spectroscopic analyses.
Furthermore, the growth and the metabolising activity of the fungi are investigated and the activity of enzymes involved in the degradation of the woody cell wall is determined. Modified cell wall polymers are used to investigate whether these enzymes are able to convert the modified substrate.