Aerobic degradation of dinitrotoluenes and pathway for bacterial degradation of 2,6-dinitrotoluene

Journal Article · Mon May 01 04:00:00 EDT 2000 · Applied and Environmental Microbiology

DOI:https://doi.org/10.1128/AEM.66.5.2139-2147.2000· OSTI ID:20075763

Nishino, S F; Paoli, G C; Spain, J C

An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. The authors report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway. Burkholderia cepacia strain JS850 and Hydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon and nitrogen. The initial steps in the pathway for degradation of 2,6-DNT were determined by simultaneous induction, enzyme assays, and identification of metabolites through mass spectroscopy and nuclear magnetic resonance. 2,6-DNT was converted to 3-methyl-4-nitrocatechol by a dioxygenation reaction accompanied by the release of nitrite. 3-Methyl-4-nitrocatechol was the substrate for extradiol ring cleavage yielding 2-hydroxy-5-nitro-6-oxohepta-2,4-dienoic acid. 2,4-DNT-degrading strains also converted 2,6-DNT to 3-methyl-4-nitrocatechol but did not metabolize the 3-methyl-4-nitrocatechol. Although 2,6-DNT prevented the degradation of 2,4-DNT by 2,4-DNT-degrading strains, the effect was not the result of inhibition of 2,4-DNT dioxygenase by 2,6-DNT or of 4-methyl-5-nitrocatechol monooxygenase by 3-methyl-4-nitrocatechol.

• Research Organization: Air Force Research Lab., Tyndall AFB, FL (US)
• OSTI ID: 20075763
• Journal Information: Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 5 Vol. 66; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
54 ENVIRONMENTAL SCIENCES
AEROBIC CONDITIONS
BIODEGRADATION
BIOLOGICAL PATHWAYS
ENZYME INDUCTION
GROUND WATER
REMEDIAL ACTION
SOILS
TNT