Microbial characterization of TNT-contaminated soils and anaerobic TNT degradation: high and unusual denitration activity

2,4,6-trinitrotoluene (TNT) is one of the most common explosives. In spite of its known toxicity and mutagenicity for many organisms, soils and groundwater are still frequently contaminated at manufacturing, disposal and TNT-destruction sites. Thirteen soil samples collected from a TNT-destruction field were investigated for their concentrations of TNT and its derivatives as well as for their microbial diversity. They contained TNT at various concentrations, ranging from 4 to 36 g TNT/kg soil. Various metabolites were also detected, including 2,4,6-trinitrobenzaldehyde, 4-amino-2,6-dinitrotoluene, 2-amino-4,6-dinitrotoluene and 2,4-dinitrotoluene. Microbial communities of these soil samples were characterized…