Catabolism of 1,3-dinitrobenzene by Rhodococcus sp. QT-1

The 1,3-dinitrobenzene-degrading Rhodococcus strain QT-1 was isolated under nitrogen limiting conditions from contaminated soil samples. Experimental data indicate that 1,3-dinitrobenzene is metabolized via 4-nitrocatechol. Both compounds were oxidized by resting cells and nitro groups were completely eliminated as nitrite. Strain QT-1 utilizes both 1,3-dinitrobenzene and 4-nitrocatechol as source of nitrogen in the absence as well as in the presence of high amounts of ammonia. Growth on 4-nitrocatechol does not induce the enzyme(s) for the initial oxidation of 1,3-dinitrobenzene.Abbreviations TNT 2,4,6-trinitrotoluene - 1,3DNB 1,3-dinitrobenzene - 4NC 4-nitrocatechol - 3NA 3-nitroaniline - NB nutrient broth; t_d doubling time - OD₅₄₆ optical density at 546 nm