Black liquor lignin biodegradation by Trametes elegans

The white rot fungus Trametes elegans was used for direct treatment of spent black liquor from pulping processes with the aim to degrade solubilized lignin which is the primary organic by-product from the chemical digestion of lignocellulosic raw materials. The enzymatic activity of T elegans and the resulting degradation was confirmed by UV/VIS spectrometric and size-exclusion chromatography (SEC) measurements on incubated and control samples of both industrial and synthetic black liquors. Opposing polymerization and depolymerization reactions occurred after treatment of the black liquor with T elegans in liquid media. It is noteworthy that these effects, which originate from ligninolytic enzyme systems, occur after the direct treatment of the black liquor even if no nutrients are added. The effect of the suspension pH and incubation time on the lignolytic action of T elegans is also presented. (C) 2003 Elsevier Ltd. All rights reserved.