Hughes, Claire orcid.org/0000-0002-9512-8052, Barton, Eleanor, Hepach, Helmke et al. (7 more authors) (2021) Oxidation of iodide to iodate by cultures of marine ammonia-oxidising bacteria. MARINE CHEMISTRY. 104000. ISSN 0304-4203
Abstract
Reaction with iodide (I−) at the sea surface is an important sink for atmospheric ozone, and causes sea-air emission of reactive iodine which in turn drives further ozone destruction. To incorporate this process into chemical transport models, improved understanding of the factors controlling marine iodine speciation, and especially sea-surface iodide concentrations, is needed. The oxidation of I− to iodate (IO3−) is the main sink for oceanic I−, but the mechanism for this remains unknown. We demonstrate for the first time that marine nitrifying bacteria mediate I− oxidation to IO3−. A significant increase in IO3− concentrations compared to media-only controls was observed in cultures of the ammonia-oxidising bacteria Nitrosomonas sp. (Nm51) and Nitrosoccocus oceani (Nc10) supplied with 9–10 mM I−, indicating I− oxidation to IO3−. Cell-normalised production rates were 15.69 (±4.71) fmol IO3− cell−1 d−1 for Nitrosomonas sp., and 11.96 (±6.96) fmol IO3− cell−1 d−1 for Nitrosococcus oceani, and molar ratios of iodate-to-nitrite production were 9.2 ± 4.1 and 1.88 ± 0.91 respectively. Preliminary experiments on nitrite-oxidising bacteria showed no evidence of I− to IO3− oxidation. If the link between ammonia and I− oxidation observed here is representative, our ocean iodine cycling model predicts that future changes in marine nitrification could alter global sea surface I− fields with potential implications for atmospheric chemistry and air quality.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Elsevier B.V. All rights reserved. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Environment and Geography (York) The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 29 Jun 2021 14:20 |
Last Modified: | 22 Jan 2025 00:16 |
Published Version: | https://doi.org/10.1002/essoar.10503313.2 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1002/essoar.10503313.2 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:175721 |
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