THREE STAGE BIOTECHNOLOGY FOR THE REHABILITATION OF SOILS POLLUTED WITH EXPLOSIVES

Widespread contamination of the environment by explosives due to the manufacture, disposal and testing of munitions has become a major international concern connected with the increasing scale of soil and ground water contamination. Most explosives are considered to be a major hazard to the biological system due to their high toxicity and mutagenic effects. Research on biotransformation of explosives has clearly shown that some plants and several families of aerobic microorganisms, representing different taxonomic groups of microorganisms, have the potential to transform TNT (2,4,6-trinitrotoluene), RDX (hexogen – hexahydro-1,3,5-trinitro-1,3,5-triazine) and other nitro organic explosives to non toxic products. Despite the existence of such extensive data, there is no reliable information dealing with the affordable clean up technology of explosives. To evaluate the disappearance of TNT and its intermediate products, in the last decade, great attention has been paid to microorganisms (both eukaryotes and prokaryotes) and plants. Microorganisms being well established detoxifiers, of structurally varying contaminants, are promising natural tools that allows to sustain the ecological balance. The ability of plants to cleanup the environment has still attracted relatively little attention, having no long story. Although plants play an important role in sustaining and restoring all niches of the environment due to their ability to absorb and metabolize quite a wide spectrum of various contaminants of organic nature, plants for cleanup the environment has attracted relatively little attention having no long story. Research carried out for more than 30 years, with annual and perennial plants and various families of different taxonomic groups of microorganisms have revealed their potential to absorb and metabolize organic contaminants of different structure. Three laboratories, at Durmishidze Institute of Biochemistry and Biotechnology (Georgia) have carried out research aimed at the creation of a new biotechnological approach for rehabilitation of soils polluted with explosives based on joint, symbiotic action of microorganisms and plants.