title: Influence of oxygen availability on the activities of ammonia-oxidizing archaea.
abstract: Recent studies point to the importance of oxygen (O2) in controlling the distribution and activity of marine ammonia-oxidizing archaea (AOA), one of the most abundant prokaryotes in the ocean. The AOA are associated with regions of low O2tension in oceanic oxygen minimum zones (OMZs), and O2availability is suggested to influence their production of the ozone-depleting greenhouse gas nitrous oxide (N2O). We show that marine AOA available in pure culture sustain high ammonia oxidation activity at low μM O2concentrations, characteristic of suboxic regions of OMZs (<10 µM O2), and that atmospheric concentrations of O2may inhibit the growth of some environmental populations. We quantify the increasing N2O production by marine AOA with decreasing O2tensions, consistent with the plausibility of an AOA contribution to the accumulation of N2O at the oxic-anoxic redox boundaries of OMZs. Variable sensitivity to peroxide also suggests that endogenous or exogenous reactive oxygen species are of importance in determining the environmental distribution of some populations.
authors.affiliation: Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
authors.affiliation: Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Kelley A
authors.initials: KA
authors.lastname: Meinhardt
authors.affiliation: Departments of Biological Sciences and Earth Sciences and Civil and Environmental Engineering, University of Southern California, Los Angeles, CA, 90089, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Moffett
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Allan H
authors.initials: AH
authors.lastname: Devol
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA, 98195, USA.
authors.forename: E
authors.initials: E
authors.lastname: Virginia Armbrust
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Anitra E
authors.initials: AE
authors.lastname: Ingalls
authors.affiliation: Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Stahl
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis / Q000502:physiology*; D001105:Archaea / Q000254:growth & development / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009609:Nitrous Oxide / Q000378:metabolism*; D009792:Oceans and Seas; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*
chemical_list: D000641:Ammonia; D006861:Hydrogen Peroxide; D009609:Nitrous Oxide; D010100:Oxygen