Open AccessRuminal bioremediation of the high energy melting explosive (HMX) by sheep microorganisms
Author(s) -
Eaton Hillary L.,
Murty Lia D.,
Duringer Jennifer M.,
Craig A. Morrie
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12316
Subject(s) - explosive material , microorganism , bioremediation , environmental chemistry , chemistry , microbiology and biotechnology , environmental science , bacteria , biology , organic chemistry , genetics
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.