Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment
Iron (Fe) is a paradox in the modern ocean it is central to many life-critical enzymes but is scarce across most surface waters. The high cellular demand and low bioavailability of Fe likely puts selective pressure on marine microorganisms. Previous observations suggest that heterotrophic bacteria a...
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Online Access: | https://doi.org/10.3389/fmars.2019.00776 http://ecite.utas.edu.au/137341 |
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ftunivtasecite:oai:ecite.utas.edu.au:137341 2023-05-15T18:24:35+02:00 Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment Fourquez, M Bressac, M Deppeler, SL Ellwood, M Obernosterer, I Trull, TW Boyd, PW 2020 application/pdf https://doi.org/10.3389/fmars.2019.00776 http://ecite.utas.edu.au/137341 en eng Frontiers Research Foundation http://ecite.utas.edu.au/137341/1/137341 - Microbial competition in the subpolar southern ocean.pdf http://dx.doi.org/10.3389/fmars.2019.00776 Fourquez, M and Bressac, M and Deppeler, SL and Ellwood, M and Obernosterer, I and Trull, TW and Boyd, PW, Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment, Frontiers in Marine Science, 6, (JAN) Article 776. ISSN 2296-7745 (2020) [Refereed Article] http://ecite.utas.edu.au/137341 Earth Sciences Oceanography Biological oceanography Refereed Article PeerReviewed 2020 ftunivtasecite https://doi.org/10.3389/fmars.2019.00776 2022-08-29T22:17:49Z Iron (Fe) is a paradox in the modern ocean it is central to many life-critical enzymes but is scarce across most surface waters. The high cellular demand and low bioavailability of Fe likely puts selective pressure on marine microorganisms. Previous observations suggest that heterotrophic bacteria are outcompeted by small diatoms for Fe supply in the subantarctic zone of Southern Ocean, thereby challenging the idea of heterotrophic bacteria being more competitive than phytoplankton in the access to this trace metal. To test this hypothesis, incubation experiments were carried out at the Southern Ocean Time Series site (MarchApril 2016). We investigated (a) whether dissolved organic carbon (DOC), dissolved Fe, or both limit the growth of heterotrophic bacteria and, (b) if the presence of potential competitors has consequences on the bacterial Fe acquisition. We observed a pronounced increase in both bulk and cell-specific bacterial production in response to single (+C) and combined (+Fe+C) additions, but no changes in these rates when only Fe was added (+Fe). Moreover, we found that +Fe+C additions promoted increases in cell-specific bacterial Fe uptake rates, and these increases were particularly pronounced (by 13-fold) when phytoplankton were excluded from the incubations. These results suggest that auto- and heterotrophs could compete for Fe when DOC limitation of bacterial growth is alleviated. Such interactions between primary producers and nutrient-recyclers are unexpected drivers for the duration and magnitude of phytoplankton blooms in the Southern Ocean. Article in Journal/Newspaper Southern Ocean eCite UTAS (University of Tasmania) Southern Ocean Frontiers in Marine Science 6 |
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eCite UTAS (University of Tasmania) |
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ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Biological oceanography |
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Earth Sciences Oceanography Biological oceanography Fourquez, M Bressac, M Deppeler, SL Ellwood, M Obernosterer, I Trull, TW Boyd, PW Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
topic_facet |
Earth Sciences Oceanography Biological oceanography |
description |
Iron (Fe) is a paradox in the modern ocean it is central to many life-critical enzymes but is scarce across most surface waters. The high cellular demand and low bioavailability of Fe likely puts selective pressure on marine microorganisms. Previous observations suggest that heterotrophic bacteria are outcompeted by small diatoms for Fe supply in the subantarctic zone of Southern Ocean, thereby challenging the idea of heterotrophic bacteria being more competitive than phytoplankton in the access to this trace metal. To test this hypothesis, incubation experiments were carried out at the Southern Ocean Time Series site (MarchApril 2016). We investigated (a) whether dissolved organic carbon (DOC), dissolved Fe, or both limit the growth of heterotrophic bacteria and, (b) if the presence of potential competitors has consequences on the bacterial Fe acquisition. We observed a pronounced increase in both bulk and cell-specific bacterial production in response to single (+C) and combined (+Fe+C) additions, but no changes in these rates when only Fe was added (+Fe). Moreover, we found that +Fe+C additions promoted increases in cell-specific bacterial Fe uptake rates, and these increases were particularly pronounced (by 13-fold) when phytoplankton were excluded from the incubations. These results suggest that auto- and heterotrophs could compete for Fe when DOC limitation of bacterial growth is alleviated. Such interactions between primary producers and nutrient-recyclers are unexpected drivers for the duration and magnitude of phytoplankton blooms in the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Fourquez, M Bressac, M Deppeler, SL Ellwood, M Obernosterer, I Trull, TW Boyd, PW |
author_facet |
Fourquez, M Bressac, M Deppeler, SL Ellwood, M Obernosterer, I Trull, TW Boyd, PW |
author_sort |
Fourquez, M |
title |
Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
title_short |
Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
title_full |
Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
title_fullStr |
Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
title_full_unstemmed |
Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment |
title_sort |
microbial competition in the subpolar southern ocean: an fe-c co-limitation experiment |
publisher |
Frontiers Research Foundation |
publishDate |
2020 |
url |
https://doi.org/10.3389/fmars.2019.00776 http://ecite.utas.edu.au/137341 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
http://ecite.utas.edu.au/137341/1/137341 - Microbial competition in the subpolar southern ocean.pdf http://dx.doi.org/10.3389/fmars.2019.00776 Fourquez, M and Bressac, M and Deppeler, SL and Ellwood, M and Obernosterer, I and Trull, TW and Boyd, PW, Microbial competition in the subpolar southern ocean: an Fe-C Co-limitation experiment, Frontiers in Marine Science, 6, (JAN) Article 776. ISSN 2296-7745 (2020) [Refereed Article] http://ecite.utas.edu.au/137341 |
op_doi |
https://doi.org/10.3389/fmars.2019.00776 |
container_title |
Frontiers in Marine Science |
container_volume |
6 |
_version_ |
1766205264025878528 |