The Molecular Biology of Nitroamine Degradation in Soils
We propose a two-pronged approach to characterize RDX degradation in soils: based on known RDX-degrading isolates and a culture independent molecular approach to characterize the microbial communities of soils polluted to varying degrees with RDX. Sequenced clone libraries combined with stable isotope probing will be used to characterize in situ microbial populations of pristine, training range, hotspot, and munitions processing polluted soils and compared with the RDX degradation rates in those microcosms. The occurrence of Rhodococcus and the diversity of xplA/B genes for RDX degradation in the environment will be determined. The relative importance of anaerobic and aerobic RDX degrading pathways will be determined. The evolutionary origin of known RDX degradation pathways will be investigated and the significance of horizontal gene transfer of xplA will be studied. Genetic control of RDX degradation will be delineated and we attempt to discover new RDX degrading bacteria and enzymes.
Our objectives are to:
Characterize the microbial communities of a range of RDX contaminated soils using molecular techniques.
Determine RDX metabolites and metabolic pathways.
Determine the evolutionary origin and environmental diversity of xplA.
Determine the mechanism of horizontal gene transfer of xplA within Rhodococcus.
Investigate the regulation and transcription of xplA in Rhodococcus.
Discover new RDX degrading bacteria and enzymes.
