A manganese peroxidase preparation of the white-rot fungus Nematoloma frowardii mineralized uniformly ring-labeled C-14-2-amino-4,6-dinitrotoluene directly to CO2. In the cell-free system, a release of 52% (CO2)-C-14 was demonstrated in the presence of reduced glutathione as secondary thiol mediator. This is the first description of the direct enzymatic combustion of an aromatic compound by an extracellular enzyme of the ligninolytic system.