In vitro Degradation of 2,4,6‐Trinitrotoluene Using Plant Tissue Cultures of <i>Solanum aviculare</i> and <i>Rheum palmatum</i>

Abstract

Abstract The degradation of TNT was tested in suspension cultures ( Rheum palmatum and Solanum aviculare ) and was followed by the identification of degradation products and the determination of the phytotoxicity of TNT to both cultures. The concentration of TNT inhibited the growth of cell cultures by 50 %, i.e., 37.8 mg/ and 38.1 mg/L for Rheum palmatum and Solanum aviculare, respectively. The TNT uptake was studied by determining the concentration of TNT and its degradation products, such as aminodinitrotoluenes and diaminonitrotoluenes, in the cultivation medium as well as in plant cells. The kinetics of the degradation showed that TNT was mostly taken up within 10 hours and 6 hours for S. aviculare and R. palmatum , respectively. Aminodinitrotoluenes were preferentially produced by cultures of S. aviculare , whereas diaminonitrotoluenes and aminodinitrotoluenes were revealed in cultures of R. palmatum . The final concentrations of identified degradation products did not stoichiometrically correspond to the decreased concentration of TNT in the medium. The different concentrations of degradation products in each culture were an indication that the metabolism of TNT is controlled by different enzymatic systems. Therefore, it was concluded that studying different species for TNT degradation is necessary for the search of most suitable candidates for TNT phytoremediation.