Effect of iron(III), humic acids and anthraquinone-2,6-disulfonate on biodegradation of cyclic nitramines by Clostridium sp. EDB2.
OBJECTIVE
To determine the biodegradation of cyclic nitramines by an anaerobic marine bacterium, Clostridium sp. EDB2, in the presence of Fe(III), humic acids (HA) and anthraquinone-2,6-disulfonate (AQDS).


RESULTS
An obligate anaerobic bacterium, Clostridium sp. EDB2, degraded RDX and HMX, and produced similar product distribution including nitrite, methylenedinitramine, nitrous oxide, ammonium, formaldehyde, formic acid and carbon dioxide. Carbon (C) and nitrogen (N) mass balance for RDX products were 87% and 82%, respectively, and for HMX were 88% and 74%, respectively. Bacterial growth and biodegradation of RDX and HMX were stimulated in the presence of Fe(III), HA and AQDS suggesting that strain EDB2 utilized Fe(III), HA and AQDS as redox mediators to transfer electrons to cyclic nitramines.


CONCLUSIONS
Strain EDB2 demonstrated a multidimensional approach to degrade RDX and HMX: first, direct degradation of the chemicals; second, indirect degradation by reducing Fe(III) to produce reactive-Fe(II); third, indirect degradation by reducing HA and AQDS which act as electron shuttles to transfer electrons to the cyclic nitramines.


CONCLUSIONS
The present study could be helpful in determining the fate of cyclic nitramine energetic chemicals in the environments rich in Fe(III) and HA.
Bhushan
B
B
Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, Canada.
Halasz
A
A
Hawari
J
J
D000880:Anthraquinones / Q000494:pharmacology*; D001392:Azocines / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D003013:Clostridium / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism*; D005290:Ferric Compounds / Q000494:pharmacology*; D006397:Hematinics / Q000494:pharmacology; D006573:Heterocyclic Compounds, 1-Ring / Q000378:metabolism*; D006812:Humic Substances; D008903:Minerals / Q000494:pharmacology; D010084:Oxidation-Reduction; D012378:Rodenticides / Q000378:metabolism; D014227:Triazines / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism
D000880:Anthraquinones; D001392:Azocines; D002614:Chelating Agents; D004785:Environmental Pollutants; D005290:Ferric Compounds; D006397:Hematinics; D006573:Heterocyclic Compounds, 1-Ring; D006812:Humic Substances; D008903:Minerals; D012378:Rodenticides; D014227:Triazines; D014874:Water Pollutants, Chemical; C408124:anthraquinone-2,6-disulfonate; C007950:octogen; C009160:cyclonite