Isolation of TNT tolerant pseudomonas species (Strain KA) from TNT contaminated soil biotransformation of TNT

Abstract

"A 2,4,6-trinitrotoluene (TNT) utilising bacterium, Pseudomonas species (strain KA) was isolated from soils of a munitions processing unit and studied for itsability to grow and metabolise TNT. The result indicated that the isolate could grow aerobically in a minimal salt medium containing 0.25 mM/l TNT at 30 °C. It could completely transform 0.25 mM/l TNT in 5 days giving 2-isomeric monoaminodinitrotoluenes, namely 4-aminodinitrotoluene and 2-aminodinitrotoluene. Products of TNT transformation were analysed and confirmed by thin layer chromatography and gas chromatography coupled with mass spectrometry. Both, growth of the isolate and biotransformation rates were better supported on sugar and ammonium salt when added to the medium separately. Pseudomonas species (strain KA) showed maximum TNT transformation efficiency in the presence of mannose. For degradation of TNT, this strain can be employed to initiate the process in association with the other microbial members that can collectively degrade TNT .