CONVERSION OF AMINONITROTOLUENES BY FUNGAL MANGANESE PEROXIDASE

Preparations of extracellular manganese peroxidase from the white-rot fungus Nematoloma frowardii and the fitter decaying fungus Stropharia rugosoannulata converted rapidly the main intermediates of the explosi ve 2,3,6-trinitrotoluene - the aminonitrotoluenes. In a cell-free syst em, 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene and 2,6-dia mino-4-nitrotoluene were degraded without formation of identifiable me tabolites. Radioactive experiments using a complex mixture of uniform ring-labeled C-14-TNT reduction products demonstrated the partial dire ct mineralization of these com pounds by manganese peroxidase. The ext ent of aminonitrotoluene conversion as well as the release of (CO2)-C- 14 from TNT reduction products were considerably enhanced in the prese nce of thiols like reduced glutathione or the amino acid L-cystein, wh ich probably act as secondary mediators.