Mass balance studies with 14C-labeled 2,4,6-trinitrotoluene (TNT) mediated by an anaerobic Desulfovibrio species and an aerobic Serratia species

• Published in: Current microbiology 1998-12, Vol.37 (6), p.380-386
• Main Authors: Drzyzga, O. (Philipps-Universitat Marburg, Marburg, Germany.), Bruns-Nagel, D, Gorontzy, T, Blotevogel, K.H, Gemsa, D, Low, E. von
• Format: Article
• Language: English
• Subjects: anaerobic conditions; Anoxic conditions; BACTERIA; Bacteriology; balance studies; BIODEGRADACION; BIODEGRADATION; Biodegradation, Environmental; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biomass; Biotechnology; Biotransformation; Carbon Radioisotopes; Chromatography, High Pressure Liquid; CONTROL DE LA CONTAMINACION; Culture Media; Desulfovibrio; Desulfovibrio - metabolism; Dinitrotoluene; Environmental Microbiology; Environmental Pollutants - metabolism; Fundamental and applied biological sciences. Psychology; LUTTE ANTIPOLLUTION; Metabolism. Enzymes; Metabolites; microbial biomass; Microbiology; Mission oriented research; Oxygen - metabolism; Physiology and metabolism; POLLUTION CONTROL; Radioactivity; SERRATIA; Serratia - metabolism; Serratia plymuthica; Time Factors; trinitrotoluene; Trinitrotoluene - metabolism
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s002849900397

Investigations were carried out to evaluate the level of incorporation of radiolabeled 2,4,6-trinitrotuluene (TNT) and metabolites into the bacterial biomass of two different bacterial species after cometabolically mediated TNT transformation. Biotransformation experiments with 14C-TNT indicated that TNT was not mineralized; however, carbon derived from TNT became associated with the cells. It was found that more than 42% of the initially applied radiolabel was associated with the cell biomass after cometabolic 14C-TNT transformation with the strictly anerobic Desulfovibrio species strain SHV, whereas with the strictly aerobic Serratia plymuthica species strain B7, 32% of cell-associated 14C activity was measured. The remainder of the radiolabel was present in the supernatants of the liquid cultures in the form of different TNT metabolites. Under anoxic conditions with the Desulfovibrio species, TNT was ultimately transformed to 2,4,6-triaminotoluene (TAT) and both diaminonitrotoluene isomers, whereas under oxic conditions with the Serratia species, TNT was converted to hydroxylaminodinitrotoluenes and aminodinitrotoluenes, with 4-amino-2,6-dinitrotoluene (4ADNT) being the major end product. In both culture supernatants, small amounts of very polar, radiolabeled, but unidentified metabolites were detected. At the end of the experiments approximately 92% and 96% of the originally applied radioactivity was recovered in the studies with the Serratia and Desulfovibrio species, respectively