Transformation and mineralization of 2,4,6-trinitrotoluene (TNT) by manganese peroxidase from the white-rot basidiomycete Phlebia radiata.
The degradation of the nitroaromatic pollutant 2,4,6-trinitrotoluene (TNT) by the manganese-dependent peroxidase (MnP) of the white-rot fungus Phlebia radiata and the main reduction products formed were investigated. In the presence of small amounts of reduced glutathione (10 mM), a concentrated cell-free preparation of MnP from P. radiata exhibiting an activity of 36 nkat/ml (36 nmol Mn(II) oxidized per sec and per ml) transformed 10 mg/l of TNT within three days. The same preparation was capable of completely transforming the reduced derivatives of TNT. When present at 10 mg/l, the aminodinitrotoluenes were transformed in less than two days and the diaminonitrotoluenes in less than three hours. Experiments with 14C-U-ring labeled TNT and 2-amino-4,6-dinitrotoluene showed that these compounds were mineralized by 22% and 76%, respectively, within 5 days. Higher concentrations of reduced glutathione (50 mM) led to a severe inhibition of the degradation process. It is concluded that Phlebia radiata is a good candidate for the biodegradation of TNT as well as its reduction metabolites.
Van Aken
B
B
Unit of Bioengineering, Catholic University of Louvain, Belgium.
Hofrichter
M
M
Scheibner
K
K
Hatakka
A I
AI
Naveau
H
H
Agathos
S N
SN
D001487:Basidiomycota / Q000201:enzymology / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D001711:Biotransformation; D005978:Glutathione / Q000494:pharmacology; D007700:Kinetics; D008903:Minerals / Q000378:metabolism; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism*; D014303:Trinitrotoluene / Q000378:metabolism* / Q000493:pharmacokinetics
D008903:Minerals; D014303:Trinitrotoluene; D010544:Peroxidases; C051129:manganese peroxidase; D005978:Glutathione