Implication of manganese (III), oxalate, and oxygen in the degradation of nitroaromatic compounds by manganese peroxidase (MnP)
(2002) Applied Microbiology and Biotechnology — Vol. 58, n° 3, p. 345-351 (2002)
Files
pdfdocument.pdf
Restricted Access - Adobe PDF
- 92.16 KB
Details
- Authors
Agathos, Spiros N. 
- Abstract
- The fungal ligninolytic enzyme manganese peroxidase (MnP) is known to function by oxidizing Mn(II) to Mn(III), a powerful oxidant. In this work, an abiotic system consisting of Mn(III) in oxalate buffer under aerobic conditions (Mn(III)/oxalate/O-2 system) was shown to be capable of extensively transforming 2-amino4,6-dinitrotoluene (2A46DNT) - one of the main reduction products of 2,4,6-trinitrotoluene (TNT). No significant transformation occurred in the presence of other organic acids or under anaerobic conditions. The Mn(lll)/oxalate/O-2 system was also able to transform other nitroaromatic compounds such as 2-nitrotoluene, 4-nitrotoluene, 2,4-dinitrotoluene, TNT - the latter to a lesser extent -, and their reduction derivatives. The Mn(lll)/oxalate/O-2 system mineralized C-14-U-ring labeled 2A46DNT slightly, while no significant mineralization of C-14-U-ring labeled TNT was observed. Unidentified C-14-transformation products were highly polar. Electron spin resonance experiments performed on the Mn(III)/oxalate/O-2 system revealed the generation of formyl free radicals (COO-). The oxygen requirement for the transformation of nitroaromatic compounds suggests the involvement of superoxide free radicals (O-2(-)), produced through autoxidation of COO- by molecular oxygen. The implication of such a Mn(III)/oxalate/O-2 system in the MnP-catalyzed degradation of nitroaromatic pollutants by white-rot fungi is further discussed.
- Affiliations
Citations
Van Aken, B., & Agathos, S. N. (2002). Implication of manganese (III), oxalate, and oxygen in the degradation of nitroaromatic compounds by manganese peroxidase (MnP). Applied Microbiology and Biotechnology, 58(3), 345-351. https://doi.org/10.1007/s00253-001-0888-1 (Original work published 2002)