Differential scanning calorimetry as a complementary tool in wood biodegradation studies

Abstract

Lignin degradation by white-rot basidiomycetes merits particular interest for several reasons. Since chemical analysis of biodegraded wood is questionable, the differential scanning calorimetry could be valuable as additional tool, particularly for lignin analyses. With intact wood the Klason-lignin content agrees with the results of DSC determination. But the more the decay of wood proceeds the more the results of the two methods diverge from each other. Therefore the chemical preparations were examined for possible artifacts, e.g. inclusion of decay products, cellulose or hemicelluloses into the Klason-lignin fraction. This could be excluded. Although the results of the Klason- and the DSC-method diverge, neither of the two methods seems to be wrong. It is therefore suggested that the energy-content of the residual lignin in white-rotted wood decreases dramatically, and that such changes can not be detected by the chemical lignin determination but only by the physical DSC analyses.