Ruminal bioremediation of the high energy melting explosive (HMX) by sheep microorganisms.

TitleRuminal bioremediation of the high energy melting explosive (HMX) by sheep microorganisms.
Publication TypeJournal Article
Year of Publication2014
AuthorsEaton HL, Murty LD, Duringer JM, Craig AM
JournalFEMS microbiology letters
Volume350
Issue1
Pagination34-41
Date Published2014 Jan
ISSN1574-6968
Abstract

The ability of ruminal microorganisms to degrade octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (high melting explosive, HMX) as consortia from whole rumen fluid (WRF), and individually as 23 commercially available ruminal strains, was compared under anaerobic conditions. Compound degradation was monitored by high-performance liquid chromatography, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for delineation of the metabolic pathway. In WRF, 30 μM HMX was degraded to 5 μM HMX within 24 h. Metabolites consistent with m/z 149, 193 and 229 were present throughout the incubation period. We propose that peaks with an m/z of 149 and 193 are arrived at through reduction of HMX to nitroso or hydroxylamino intermediates, then direct enzymatic ring cleavage to produce these HMX derivatives. Possible structures of m/z 229 are still being investigated and require further LC-MS/MS analysis. None of the 23 ruminal strains tested were able to degrade HMX as a pure culture when grown in either a low carbon or low nitrogen basal medium over 120 h. We conclude that microorganisms from the rumen, while sometimes capable as individuals in the bioremediation of other explosives, excel as a community in the case of HMX breakdown.

DOI10.1111/1574-6968.12316
Alternate JournalFEMS Microbiol. Lett.