METABOLISM OF TRINITROBENZENE BY A PSEUDOMONAS CONSORTIUM

The metabolism of trinitrobenzene by a Pseudomonas consortium was stud ied. The Pseudomonas consortium used trinitrobenzene as a sole source of nitrogen, but not as a sole source of carbon. Trinitrobenzene was m etabolized within 60 h of incubation. The main intermediates produced were dinitroaniline, 1,5 dinitrobenzene, nitroaniline, 5-nitrobenzene, and ammonia. The ammonia concentration in the culture medium increase d during the course of incubation. Nearly stoichiometric amounts of 1, 5-dinitrobenzene and 5-nitrobenzene were produced by the consortium. D uring trinitrobenzene metabolism by this bacterial consortium, the tri nitrobenzene was first reduced to an amino compound, dinitroaniline. T his intermediate was reductively deaminated with the release of ammoni a into the culture medium and production of 1,5-dinitrobenzene. By the same mechanism, 1,5-dinitrobenzene was further converted to 5-nitrobe nzene, which was not metabolized further, even after 60 days of incuba tion. This pathway is believed to be novel in that an aerobic bacteria l consortium uses the nitroaromatic compound as its nitrogen source bu t leaves the ring intact. The bacterial consortium studied could be us ed in a syntrophic culture system with other 5-nitrobenzene-degrading bacteria to remove trinitrobenzene completely from soil and water at c ontaminated sites.