Many microbes reduce the nitro substituents of 2,4,6-trinitrotoluene (TNT), producing aminodinitrotoluenes (ADNTs). These compounds are recalcitrant to further breakdown and are acutely toxic. In a search for organisms capable of metabolizing ADNTs, a bacterial strain was isolated for the ability to use 2-aminobenzoate (anthranilate) as sole C-source. This isolate, Pseudomonas aeruginosa MAO1, metabolized TNT by first reducing one nitro group to form either 2-amino-4,6-dinitrotoluene (2ADNT) or 4 -amino-2,6-dinitrotoluene(4ADNT). However, strain MA01 was distinct from other TNT-reducing organisms in that it transformed these compounds into highly polar metabolites through an 02-dependent process. Strain MAOl was able to cometabolize TNT, 2ADNT, and 4ADNT in the presence of a variety of carbon and energy sources. During aerobic cometabolism with succinate, 45% of uniformly ring-labeled [14C]TNT was transformed to highly polar compounds. Aerobic cometabolism of purified [14C]2ADNT and [14C]4ADNT with succinate as C-source produced similar amounts of these polar metabolites. During O2-limited cometabolism with succinate as C-source and nitrate as electron acceptor, less than 8% of the [14C]TNT was transformed to polar metabolites. Purified 2,6-diamino-4 -nitrotoluene was not metabolized, and while 2,4-diamino-6-nitrotoluenewas acetylated, the product (N-acetyl-2,4-diamino-6-nitrotoluene) was not further metabolized. Therefore, strain MA0l metabolized TNT by oxidation of the ADNTs and not by reduction the remaining nitro groups on the ADNTs.



Publisher statement

Reproduction of multiple copies of materials on this site, in whole or in part, for the purposes of commercial redistribution is prohibited except with written permission from the Government of Canada's copyright administrator, Public Works and Government Services Canada (PWGSC).

Included in

Biology Commons



URL: http://digitalcommons.calpoly.edu/bio_fac/57