(Bio)degradation of RDX and HMX in Marine/Estuarine Water and Sediments
Final rept. 1 Jan 2003-30 Jun 2006
NATIONAL RESEARCH COUNCIL OF CANADA MONTREAL (QUEBEC) BIOTECHNOLOGY RESEARCH INST
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The present study was initiated to provide US Navy with scientific data to help understand the environmental fate of RDX and HMX in marine environments. Two types of sediments were selected, one from a cold Atlantic site near Halifax, and another from a tropical Pacific site near Hawaii. Extensive analysis of sediments and water from both sites only showed the presence of DNT and TNT in two UXO sites from Hawaii. Indigenous microorganisms in both sites were found capable of degrading both RDX and HMX. Subsequent microbial characterization led to the isolation of several bacterial and fungal species capable of biodegrading the two nitramines. Kinetics determination and product analysis identified two major degradation routes. One route involved initial denitration followed by ring cleavage and a second route involved reduction of the N-NO2 to the corresponding N-NO bonds prior to ring cleavage and decomposition. Some of the bacteria discovered were identified as novel species of Shewanella and are being sequenced for their genomes by DOE, US, making them the first explosives degraders to be sequenced for their genomes.
- Physical and Dynamic Oceanography
- Ammunition and Explosives