Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean
Iron (Fe) is known to be mostly bound to organic ligands and to limit primary productivity in the Southern Ocean. It is thus important to investigate the bioavailability of organically bound Fe. In this study, we used four phytoplankton species of the Southern Ocean ( Phaeocystis sp., Chaetoceros sp...
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ftdoajarticles:oai:doaj.org/article:5d09127d3f8a438981f6073f0bb55a00 2023-05-15T13:42:24+02:00 Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean C. S. Hassler V. Schoemann 2009-10-01T00:00:00Z https://doaj.org/article/5d09127d3f8a438981f6073f0bb55a00 EN eng Copernicus Publications http://www.biogeosciences.net/6/2281/2009/bg-6-2281-2009.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 https://doaj.org/article/5d09127d3f8a438981f6073f0bb55a00 Biogeosciences, Vol 6, Iss 10, Pp 2281-2296 (2009) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2009 ftdoajarticles 2022-12-31T08:44:25Z Iron (Fe) is known to be mostly bound to organic ligands and to limit primary productivity in the Southern Ocean. It is thus important to investigate the bioavailability of organically bound Fe. In this study, we used four phytoplankton species of the Southern Ocean ( Phaeocystis sp., Chaetoceros sp., Fragilariopsis kerguelensis and Thalassiosira antarctica Comber ) to measure the influence of various organic ligands on Fe solubility and bioavailability. Short-term uptake Fe:C ratios were inversely related to the surface area to volume ratios of the phytoplankton. The ratio of extracellular to intracellular Fe is used to discuss the relative importance of diffusive supply and uptake to control Fe bioavailability. The effect of excess organic ligands on Fe bioavailability cannot be solely explained by their effect on Fe solubility. For most strains studied, the bioavailability of Fe can be enhanced relative to inorganic Fe in the presence of porphyrin, catecholate siderophore and saccharides whereas it was decreased in presence of hydroxamate siderophore and organic amine. For Thalassiosira , iron bioavailability was not affected by the presence of porphyrin, catecholate siderophore and saccharides. The enhancement of Fe bioavailability in presence of saccharides is presented as the result from both the formation of bioavailable (or chemically labile) organic form of Fe and the stabilisation of Fe within the dissolved phase. Given the ubiquitous presence of saccharides in the ocean, these compounds might represent an important factor to control the basal level of soluble and bioavailable Fe. Results show that the use of model phytoplankton is promising to improve mechanistic understanding of Fe bioavailability and primary productivity in HNLC regions of the ocean. Article in Journal/Newspaper Antarc* Antarctica Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 C. S. Hassler V. Schoemann Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Iron (Fe) is known to be mostly bound to organic ligands and to limit primary productivity in the Southern Ocean. It is thus important to investigate the bioavailability of organically bound Fe. In this study, we used four phytoplankton species of the Southern Ocean ( Phaeocystis sp., Chaetoceros sp., Fragilariopsis kerguelensis and Thalassiosira antarctica Comber ) to measure the influence of various organic ligands on Fe solubility and bioavailability. Short-term uptake Fe:C ratios were inversely related to the surface area to volume ratios of the phytoplankton. The ratio of extracellular to intracellular Fe is used to discuss the relative importance of diffusive supply and uptake to control Fe bioavailability. The effect of excess organic ligands on Fe bioavailability cannot be solely explained by their effect on Fe solubility. For most strains studied, the bioavailability of Fe can be enhanced relative to inorganic Fe in the presence of porphyrin, catecholate siderophore and saccharides whereas it was decreased in presence of hydroxamate siderophore and organic amine. For Thalassiosira , iron bioavailability was not affected by the presence of porphyrin, catecholate siderophore and saccharides. The enhancement of Fe bioavailability in presence of saccharides is presented as the result from both the formation of bioavailable (or chemically labile) organic form of Fe and the stabilisation of Fe within the dissolved phase. Given the ubiquitous presence of saccharides in the ocean, these compounds might represent an important factor to control the basal level of soluble and bioavailable Fe. Results show that the use of model phytoplankton is promising to improve mechanistic understanding of Fe bioavailability and primary productivity in HNLC regions of the ocean. |
format |
Article in Journal/Newspaper |
author |
C. S. Hassler V. Schoemann |
author_facet |
C. S. Hassler V. Schoemann |
author_sort |
C. S. Hassler |
title |
Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
title_short |
Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
title_full |
Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
title_fullStr |
Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
title_full_unstemmed |
Bioavailability of organically bound Fe to model phytoplankton of the Southern Ocean |
title_sort |
bioavailability of organically bound fe to model phytoplankton of the southern ocean |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
https://doaj.org/article/5d09127d3f8a438981f6073f0bb55a00 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_source |
Biogeosciences, Vol 6, Iss 10, Pp 2281-2296 (2009) |
op_relation |
http://www.biogeosciences.net/6/2281/2009/bg-6-2281-2009.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 https://doaj.org/article/5d09127d3f8a438981f6073f0bb55a00 |
_version_ |
1766167541409906688 |