Biological transformation of 2,4,6-trinitrotoluene (TNT) by soil bacteria isolated from TNT-contaminated soil

• Published in: Bioresource technology Vol. 47; no. 1; pp. 19 - 24
• Main Authors: Boopathy, R., Wilson, M., Montemagno, C.D., Manning, J.F., Kulpa, C.F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1994; Elsevier Science
• Subjects: Applied sciences; biodegradation; Biodegradation of pollutants; Biological and medical sciences; Biotechnology; Decontamination. Miscellaneous; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Pollution; Pseudomonas; remediation; Soil and sediments pollution; TNT; transformation; remediation; biodegradation; TNT; Pseudomonas; transformation; Pseudomonadales; Biodegradation; Applied microbiology; Trinitrotoluene; Microflora; Military environment; Soil pollution; Pollutant; Soils; Decontamination; Biotransformation; Bacteria; Benzenic compound; Pseudomonadaceae; Explosives; Organic compounds; Chemical contamination
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/0960-8524(94)90023-X

Four Pseudomonas spp. were isolated from a soil consortium enriched from soil contaminated with 2,4,6-trinitrotoluene (TNT). All four species extensively transformed TNT. The rate of transformation varied among species. In isolate 4, 100% of TNT (100 ppm) was transformed in 4 days. The TNT transformation was achieved by the four isolates through a co-metabolic process with a succinate co-substrate. The four isolates produced NO 2 − from TNT. The maximum NO 2 − production, observed for isolate 1, was equal to 30% of the NO 2 − available from the nitro groups of TNT. For other isolates the NO 2 − production varied from 10 to 16%. The radiolabeling studies showed signs ring cleavage. Isolate 3 used 13% of 14C-TNT to make cellular material, and isolate 4 converted 6% of 14C-TNT to biomass. The production of 14C-CO 2 was observed for all four isolates, but the amount of 14C-CO 2 produced was quite low: isolate 4 produced 14C-CO 2 from approximately 1% of 14C-TNT. The rate of degradation of TNT intermediates was very slow, reflecting possible difficulties in metabolizing the intermediates of TNT to CO 2. The main intermediates were identified as 4-amino-2,6-dinitrotoluene and 2-amino-4,6-dinitrotoluene.