title: Carbon-thirteen cross-polarization magic angle spinning nuclear magnetic resonance and Fourier transform infrared studies of thermally modified wood exposed to brown and soft rot fungi.
abstract: Thermally modified wood has many technically interesting properties, such as increased dimensional stability, low equilibrium moisture content, and enhanced biological and weather resistance. This paper describes solid-state nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopic studies on the decay of heat-treated and untreated pine (Pinus sylvestris) by brown (Poria placenta) and soft rot fungi. Both techniques combined with multivariate data analysis proved to be powerful tools for the study of wood degradation by fungi. When untreated pine was exposed to brown or soft rot fungi, a drastic decay of the cell wall polysaccharides was observed. Brown rot fungus degraded mainly hemicelluloses while soft rot fungus attacked cellulose more extensively. The aromatic region of 13C cross-polarization magic angle spinning (CPMAS) NMR spectra revealed that the structure of lignin was also altered. New carboxylic structures were formed as a consequence of the decay. The increased biological resistance of pine wood heat-treated at >220 degrees C was observed in the 13C CPMAS NMR and IR spectra.
authors.affiliation: Laboratory of Polymer Chemistry, University of Helsinki, Finland.
authors.forename: Hanne
authors.initials: H
authors.lastname: Sivonen
authors.forename: Mari
authors.initials: M
authors.lastname: Nuopponen
authors.forename: Sirkka L
authors.initials: SL
authors.lastname: Maunu
authors.forename: Franciska
authors.initials: F
authors.lastname: Sundholm
authors.forename: Tapani
authors.initials: T
authors.lastname: Vuorinen
mesh_terms: D001487:Basidiomycota / Q000737:chemistry / Q000378:metabolism* / Q000472:pathogenicity; D001673:Biodegradation, Environmental; D002247:Carbon Isotopes; D002482:Cellulose / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D006358:Hot Temperature; D008031:Lignin / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D028223:Pinus / Q000737:chemistry* / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D018547:Plant Stems / Q000737:chemistry / Q000382:microbiology; D020072:Polyporales / Q000737:chemistry / Q000472:pathogenicity; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D025341:Principal Component Analysis; D012987:Soil; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013113:Spin Labels; D014934:Wood
chemical_list: D002247:Carbon Isotopes; D011134:Polysaccharides; D012987:Soil; D013113:Spin Labels; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin