Bacterial metabolism of 2,6-dinitrotoluene with Salmonella typhimurium and mutagenicity of the metabolites of 2,6-dinitrotoluene and related compounds.

1. Metabolites produced by the incubation of 2,6-dinitrotoluene (2,6-DNT) with Salmonella typhimurium strains TA 98, TA 98/1,8-DNP6 and TA 98NR were examined. Mutagenicities of bacterial products and related compounds were also examined in the Ames assay using TA 98 and TA 100. 2. 2,6-DNT was converted to 2-nitroso-6-nitrotoluene, 2-hydroxylamino-6-nitrotoluene and 2-amino-6-nitrotoluene, with concurrent spontaneous formation of 2,2'-dimethyl-3,3'-dinitroazoxybenzene, in the incubation with TA 98 and TA 98/1,8-DNP6. Capacity of TA 98NR to reduce 2,6-DNT was much lower than that of TA 98 and TA 98/1,8-DNP6. 3. Bacterial products, including 2,2'-dimethyl-3,3'-dinitroazoxybenzene, showed no mutagenic activity in the Ames assay. 4. Results indicate that the lack of mutagenic activity of 2,6-DNT is not due to low reductive metabolism of 2,6-DNT by bacteria, but due to the lack of mutagenic activity of the bacterial reductive products of 2,6-DNT.