The effect of 2,6 dinitrotoluene on 2,4 dinitrotoluene degradation
- Air Force, Tyndall AFB, FL (United States). Armstrong Lab.
2,4-Dinitrotoluene (2,4-DNT) are by products of the manufacture of 2,4,6-trinitrotoluene (TNT) which persist as soil contaminants at manufacturing sites. Such sites are ready source of bacteria able to mineralize 2,4-DNT, but to date no bacteria able to grow on 2,6-DNT have been isolated. The pathway for degradation of 2,4-DNT proceeds through dioxygenation of 2,4-DNT to yield 4-methyl-5-nitrocatechol; monooxygenation of the methylnitrocatechol then yields 2-hydroxy-5-methylquinone which is subsequently reduced to 2,4,5-trihydroxytoluene prior to ring cleavage. Monooxygenation of 4-methyl-5-nitrocatechol appears to be the critical step, because the methylnitrocatechol is toxic to the bacteria at concentrations of 1O{sup {minus}5}M. Strains able to grow on 2,4-DNT were unable to grow on 2,6-DNT, however, such strains produced a metabolite from 2,6-DNT whose UV spectrum and retention time resembled that of 4-methyl-5-nitrocatechol. Cultures grown on 2,4-DNT then incubated in the presence of mixtures of 2,4-DNT and 2,6-DNT were inhibited in the degradation of 2,4-DNT, and 4-methyl-5-nitrocatechol accumulated in the culture fluid. These results suggest that 3-methyl-4-nitrocatechol from 2,6-DNT is the inhibitory compound that prevents 2,6-DNT degradation by bacteria able to grow on 2,4-DNT which would explain why both isomers persist at TNT production sites.
- OSTI ID:
- 382704
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
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