Rahal, A. Gh. and Lobna A. Moussa( 2011). Degradation Of 2,4,6-Trinitrotoluene (TNT)By Soil Bacteria Isolated From
TNT Contaminated Soil
Australian Journal of Basic and Applied Sciences, 5(2): 8-17, 2011
ISSN 1991-8178
Abstract: Twenty bacterial strains isolated from TNT contaminated soil. Among those strains only five were highly efficient for their abilities to grow in basal salt medium containing TNT as sole
nitrogen source. From these isolates only two strains were more potent for TNT degradation in aerobic condition. These strains were identified as Clavibacter agropyi (Corynebacterium) (R.L1) and Sphingomonas sanguinis (R.L2).These strains had shown good growth with disappearance of TNT and
concomitantly release of nitrite over the period of incubation time. TNT and its metabolites were analyzed by gas chromatography (GC) and results were confirmed and identified by gas
chromatography/Mass spectrometer (GC/MS). The biodegradation of TNT was initially similar regardless of the microorganism. Generally, the initial degradation involved the reduction or removal of the nitro substitute giving way to an amino derivative or free nitrite. The identified amino
derivatives were, P-toluidine,3,5-dinitro and Benzenamine,2-methyl-3,5-dinitro.which are known as 2-
amino-4,6-dinitrotoluene(2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) respectively. Nitrite liberation was consistently found coincided with TNT disappearance from the medium. The disappearance of TNT was completely within 7days by the two isolates and/or their mixture. This is encouraging, and may indicate their potential in bioremediation of TNT contaminated soils. This is the first report on Clavibacterium agropyri (Corynebacterium) and Sphingomonas sanguinis for degradation of TNT with nitrite release into the medium.
Keywords: (Degradation, TNT, Contaminants, Biodegradation, Environment, GC, GC/MS analysis.)
