COMETABOLIC TRANSFORMATION AND CLEAVAGE OF NITRODIPHENYLAMINES BY 3 NEWLY ISOLATED SULFATE-REDUCING BACTERIAL STRAINS

Three sulfate-reducing bacterial strains (Desulfovibrio sp. strain SHV , Desulfococcus so, strain WHC, and Desulfomicrobium so, strain WHB) w ith the capacity to cometabolize 2-nitrodiphenylamine, 4-nitrodiphenyl amine, and 2,4-dinitrodiphenylamine were newly, isolated, Before break ing down the diphenylamine structure, these strains cometabolically re duce the nitrodiphenylamines to the corresponding aminodiphenylamines during anaerobic oxidation of the growth substrate lactate (Desulfovib rio strain SHV and Desulfomicrobium strain WHC) or benzoate (Desulfoco ccus strain WHB), leading to the formation of aniline and a smatter qu antity of methylaniline. These compounds were not further metabolized by the sulfate reducers. The anaerobic metabolism of aminodiphenylamin es also led to the formation of heterocyclic condensation products suc h as phenazine and acridine derivatives, provided that they contained an amino group in the ortho position of the diphenylamine (e.g., 2-ami nodiphenylamine or 2,4-diaminodiphenylamine). In addition, low levels of indole and benzothiazole derivatives were identified, but these als o were not further metabolized by the three sulfate-reducing strains.