Physiology, Biochemistry, and Genetics of a Pure Culture of an ObligaloryAnaerobic Bacterium That Utilizes 2,4,6-Trinitrotoluene (TNT)

摘要

This work has contributed to the development of processes for bio remediation ofexplosives-contaminated soils ana waters. We examined the role of micro-bial consortia and pure strains of Clostridium spp. In the bio-degradation of TNT and other nitroaromatic contaminants. C. bifermentans, an anaerobe isolated from an enrichment of munitions-contaminated soil, degraded TNT co-metabolically. We identified reductive TNT transformations that produced triaminotoluene (TAT) and phenolic products of TAT hydrolysis. Since clostridia are common in soils, the addition of fermentable sugars to TNT contaminated soils should stimulate the reactions we observed. Examination of the ability of clostridial strains isolated from a munition enrichment, non-adapted clostridial, and other bacterial strains to degrade TNT indicated that the ability to reduce TNT anaerobically is a general phenomenon and that the TNT degradative pathways are not inducible, but are associated with constitutively expressed metabolic functions of Clostridium spp. We showed that bulk production of clostridial spores is clearly achievable for use in bio-augmentation or bio remediation systems. Overall, our work with anaerobic consortia and with pure cultures derived from the consortia indicates a complex TNT bio-degradation process in soil, which involves multiple organisms acting synergistically and probably sequentially.