C-13 CP MAS SOLID-STATE NMR AND FT-IR SPECTROSCOPY OF WOOD CELL-WALL BIODEGRADATION/

The study of the degradation carried out by microorganisms on plant ce ll walls poses several problems in the analysis of the degraded solid materials. In this article this analytical problem has been studied by solid-state, high-resolution, carbon-13 cross-polarization/magic angl e spinning nuclear magnetic resonance (CP/MAS NMR) and Fourier-transfo rmed infrared (FT-IR) spectroscopy. These two nondestructive technique s proved to be able to give insights into the modifications at a molec ular level that the cell wall components undergo during attack by Basi diomycetes fungi. Spruce (Pinus sylvestris) and beech wood samples (Fa gus sylvatica) were exposed for 6 weeks to the activity of brown-rot ( Coniophora puteana) and white-rot (Coriolus versicolor) fungi. Brown-r ot fungi appeared preferentially to degrade the polysaccharides, leavi ng a modified lignin network, whereas white-rot fungi were able to deg rade extensively both the polysaccharides and the lignin. A quantitati ve approach based on integration of CP/MAS NMR spectra showed that spr uce lignin was degraded to 77% of its weight by brown-rot, and to 39% by white-rot fungi.