%0 Journal Article
%T Anaerobic nitrification-denitrification mediated by Mn-oxides in meso-tidal sediments: Implications for N-2 and N2O production
%+ Institut méditerranéen d'océanologie (MIO)
%+ MEB
%A Fernandes, Sheryl
%A Javanaud, Cedric
%A Aigle, Axel
%A Michotey, Valerie
%A Guasco, Sophie
%A Deborde, Jonathan
%A Deflandre, Bruno
%A Anschutz, Pierre
%A Bonin, Patricia
%< avec comité de lecture
%Z MIO:15-013
%@ 0924-7963
%J Journal of Marine Systems
%I Elsevier
%V 144
%P 1-8
%8 2015-04
%D 2015
%R 10.1016/j.jmarsys.2014.11.011
%K Anaerobic
%K Anammox
%K Denitrification
%K Manganese oxides
%K Nitrification
%K Nitrous oxide
%K Sediments
%Z Environmental Sciences/Biodiversity and Ecology
%Z Life Sciences [q-bio]/Ecology, environment/Symbiosis
%Z Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biologyJournal articles
%X Field measurements in the Arcachon Bay (southwest France) indicated anaerobic production of NOx via nitrification, which was coupled to the reduction of Mn-oxides. To prove the occurrence of this process, laboratory microcosm experiments were set up. A 15N tracer-based approach was used to track if NOx produced through Mn-oxide-mediated anaerobic nitrification would be reduced to N2 via denitrification or anammox. We also hypothesized the generation of the potent greenhouse gas nitrous oxide (N2O) during nitrification–denitrificationin the presence ofMn-oxides. The microcosmswere prepared using sediment sectioned at varying depths (0–2.5, 2.5–4.5, 4.5–8.5, 8.5–12 and 12–17 cm) during two sampling campaigns in October (fall) and January (winter).Labeling with 15NO3− revealed low N2 production originating from NO3− in the water column (Pw), which didnot increase significantly on amendment with Mn-oxides during both sampling periods. However, for both seasons,a significant increase of N2 produced via nitrification (Pn) was observed upon addition of Mn-oxides reaching 76-fold enhancement at≤2.5 cm. To support these results, sediment slurries of October were subjected to amendment of 15NH4+, 14NO3− with or without addition of Mn-oxides. A substantial production of P15 (N2production from 15NH4+) within 0–17 cm provided further evidence on nitrification–denitrification mediated by Mn-oxides probably with minimal intervention of anammox. In organically rich sediments, anaerobic nitrification–denitrification mediated by Mn-oxides could play an important role in lowering re-mineralized NH4+ evels in the benthic system. As hypothesized, significant production of N2O through the pathway was observedrevealing newer mechanisms leading to the generation of the radiative gas.
%G English
%L hal-01157960
%U https://hal.science/hal-01157960
%~ SDE
%~ INSU
%~ UNIV-TLN
%~ CNRS
%~ UNIV-AMU
%~ MIO
%~ OSU-INSTITUT-PYTHEAS
%~ GIP-BE
%~ MIO-MEB