REDUCTION OF NITRATED DIPHENYLAMINE DERIVATIVES UNDER ANAEROBIC CONDITIONS

2-Nitrodiphenylamine, 4-nitrodiphenylamine, and 2,4-dinitrodiphenylami ne were anaerobically metabolized in sediment-water batch enrichments inoculated with mud from the German North Sea coast. The first interme diate in 2,4-dinitrodiphenylamine degradation was 2-amino-4-nitrodiphe nylamine, which appeared in large (nearly stoichiometric) amounts befo re being completely reduced to 2,4-diaminodiphenylamine. Of the second theoretically expected metabolite, 4-amino-2-nitrodiphenylamine, only traces were detected by gas chromatographic-mass spectrometric analys is in highly concentrated extracts. In addition, low levels of 4-nitro diphenylamine, which may be the product of ortho deamination of interm ediately. produced 2-amino-4-nitrodiphenylamine, were observed. 2-Nitr odiphenylamine and 4-nitrodiphenylamine were primarily reduced to 2-am inodiphenylamine and 4-aminodiphenylamine, respectively. Diphenylamine was never detected in any experiment as a theoretically possible inte rmediate. Results from studies with dense cell suspensions of anaerobi c, aromatic-compound-mineralizing bacteria confirmed the transformatio n reactions, which were carried out by microorganisms indigenous to th e anaerobic coastal water sediment.