In vivo-decolorization of coal-derived humic acids by laccase-excreting fungus Trametes versicolor

Lignite (brown coal) can be liquefied/solubilized with several fungi by dif ferent mechanisms. When applied industrially, only catalytic mechanisms can compete with chemical methods. The well-known fungal ligninolytic peroxida ses are at a disadvantage, in that the relatively expensive hydrogen peroxi de must be used as a cofactor. Comparing several fungal strains, we observe d that the fungus Trametes versicolor is able to decolorize coal-derived hu mic acids, producing a considerable amount of laccase in the process. Durin g this reaction the amount of humic acids decreases whilst that of fulvic a cids increases; this was verified by optical density measurement and GPC af ter the two substance classes bad been separated.