title: Biotransformation and Degradation of the Insensitive Munitions Compound, 3-Nitro-1,2,4-triazol-5-one, by Soil Bacterial Communities.
abstract: Insensitive munitions (IM) are a new class of explosives that are increasingly being adopted by the military. The ability of soil microbial communities to degrade IMs is relatively unknown. In this study, microbial communities from a wide range of soils were tested in microcosms for their ability to degrade the IM, 3-nitro-1,2,4-triazol-5-one (NTO). All seven soil inocula tested were able to readily reduce NTO to 3-amino-1,2,4-triazol-5-one (ATO) via 3-hydroxyamino-1,2,4-triazol-5-one (HTO), under anaerobic conditions with H2 as an electron donor. Numerous other electron donors were shown to be suitable for NTO-reducing bacteria. The addition of a small amount of yeast extract (10 mg/L) was critical to diminish lag times and increased the biotransformation rate of NTO in nearly all cases indicating yeast extract provided important nutrients for NTO-reducing bacteria. The main biotransformation product, ATO, was degradable only in aerobic conditions, as evidenced by a rise in the inorganic nitrogen species nitrite and nitrate, indicative of nitrogen-mineralization. NTO was nonbiodegradable in aerobic microcosms with all soil inocula.
authors.affiliation: †Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona 85721-0011, United States.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Krzmarzick
authors.forename: Raju
authors.initials: R
authors.lastname: Khatiwada
authors.affiliation: †Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona 85721-0011, United States.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Olivares
authors.forename: Leif
authors.initials: L
authors.lastname: Abrell
authors.affiliation: †Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona 85721-0011, United States.
authors.forename: Reyes
authors.initials: R
authors.lastname: Sierra-Alvarez
authors.forename: Jon
authors.initials: J
authors.lastname: Chorover
authors.affiliation: †Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona 85721-0011, United States.
authors.forename: James A
authors.initials: JA
authors.lastname: Field
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001711:Biotransformation; D053834:Explosive Agents / Q000378:metabolism*; D064307:Microbiota; D009574:Nitro Compounds / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D012988:Soil Microbiology; D014230:Triazoles / Q000378:metabolism*
chemical_list: C505897:3-nitro-1,2,4-triazol-5-one; D053834:Explosive Agents; D009574:Nitro Compounds; D014230:Triazoles; D009584:Nitrogen