Heme b quotas are low in Southern Ocean phytoplankton
Heme is the iron-containing prosthetic group of hemoproteins, and is thus required for photosynthesis, respiration and nitrate reduction in marine phytoplankton. Here we report concentrations of heme b in Southern Ocean phytoplankton and contrast our findings with those in coastal species. The conce...
Published in: | Marine Ecology Progress Series |
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Inter Research
2015
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Online Access: | https://oceanrep.geomar.de/id/eprint/29405/ https://oceanrep.geomar.de/id/eprint/29405/1/m532p029.pdf https://doi.org/10.3354/meps11345 |
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ftoceanrep:oai:oceanrep.geomar.de:29405 2023-05-15T18:23:57+02:00 Heme b quotas are low in Southern Ocean phytoplankton Gledhill, Martha Gerringa, L. J. A Laan, P. Timmermans, K. R. 2015-07-21 text https://oceanrep.geomar.de/id/eprint/29405/ https://oceanrep.geomar.de/id/eprint/29405/1/m532p029.pdf https://doi.org/10.3354/meps11345 en eng Inter Research https://oceanrep.geomar.de/id/eprint/29405/1/m532p029.pdf Gledhill, M. , Gerringa, L. J. A., Laan, P. and Timmermans, K. R. (2015) Heme b quotas are low in Southern Ocean phytoplankton. Open Access Marine Ecology Progress Series, 532 . pp. 29-40. DOI 10.3354/meps11345 <https://doi.org/10.3354/meps11345>. doi:10.3354/meps11345 info:eu-repo/semantics/openAccess Article PeerReviewed 2015 ftoceanrep https://doi.org/10.3354/meps11345 2023-04-07T15:20:15Z Heme is the iron-containing prosthetic group of hemoproteins, and is thus required for photosynthesis, respiration and nitrate reduction in marine phytoplankton. Here we report concentrations of heme b in Southern Ocean phytoplankton and contrast our findings with those in coastal species. The concentration of particulate heme b (pmol l-1) observed at the end of the exponential growth phase was related to the concentration of dissolved iron in the culture media. Small Southern Ocean phytoplankton species (<6 μm in diameter) had heme b quotas <1 μmol mol-1 carbon, the lowest yet reported for marine phytoplankton. Heme b was also depleted in these species with respect to chlorophyll a. We calculated the amount of carbon accumulated per mole of heme b per second in our cultures (heme growth efficiency, HGE) and found that small Southern Ocean species can maintain growth rates, even while heme b content is reduced. Small Southern Ocean phytoplankton can thus produce more particulate carbon than larger Southern Ocean or small coastal species at equivalent iron concentrations. Combining primary productivity and heme b concentrations reported for the open ocean, we found that HGE in natural populations was within the range of our laboratory culture results. HGE was also observed to be higher at open ocean stations characterized by low iron concentrations. Our results suggest that low heme b quotas do not necessarily result in reduced growth and that marine phytoplankton can optimize iron use by manipulating the intracellular hemoprotein pool Article in Journal/Newspaper Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Southern Ocean Marine Ecology Progress Series 532 29 40 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Heme is the iron-containing prosthetic group of hemoproteins, and is thus required for photosynthesis, respiration and nitrate reduction in marine phytoplankton. Here we report concentrations of heme b in Southern Ocean phytoplankton and contrast our findings with those in coastal species. The concentration of particulate heme b (pmol l-1) observed at the end of the exponential growth phase was related to the concentration of dissolved iron in the culture media. Small Southern Ocean phytoplankton species (<6 μm in diameter) had heme b quotas <1 μmol mol-1 carbon, the lowest yet reported for marine phytoplankton. Heme b was also depleted in these species with respect to chlorophyll a. We calculated the amount of carbon accumulated per mole of heme b per second in our cultures (heme growth efficiency, HGE) and found that small Southern Ocean species can maintain growth rates, even while heme b content is reduced. Small Southern Ocean phytoplankton can thus produce more particulate carbon than larger Southern Ocean or small coastal species at equivalent iron concentrations. Combining primary productivity and heme b concentrations reported for the open ocean, we found that HGE in natural populations was within the range of our laboratory culture results. HGE was also observed to be higher at open ocean stations characterized by low iron concentrations. Our results suggest that low heme b quotas do not necessarily result in reduced growth and that marine phytoplankton can optimize iron use by manipulating the intracellular hemoprotein pool |
format |
Article in Journal/Newspaper |
author |
Gledhill, Martha Gerringa, L. J. A Laan, P. Timmermans, K. R. |
spellingShingle |
Gledhill, Martha Gerringa, L. J. A Laan, P. Timmermans, K. R. Heme b quotas are low in Southern Ocean phytoplankton |
author_facet |
Gledhill, Martha Gerringa, L. J. A Laan, P. Timmermans, K. R. |
author_sort |
Gledhill, Martha |
title |
Heme b quotas are low in Southern Ocean phytoplankton |
title_short |
Heme b quotas are low in Southern Ocean phytoplankton |
title_full |
Heme b quotas are low in Southern Ocean phytoplankton |
title_fullStr |
Heme b quotas are low in Southern Ocean phytoplankton |
title_full_unstemmed |
Heme b quotas are low in Southern Ocean phytoplankton |
title_sort |
heme b quotas are low in southern ocean phytoplankton |
publisher |
Inter Research |
publishDate |
2015 |
url |
https://oceanrep.geomar.de/id/eprint/29405/ https://oceanrep.geomar.de/id/eprint/29405/1/m532p029.pdf https://doi.org/10.3354/meps11345 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/29405/1/m532p029.pdf Gledhill, M. , Gerringa, L. J. A., Laan, P. and Timmermans, K. R. (2015) Heme b quotas are low in Southern Ocean phytoplankton. Open Access Marine Ecology Progress Series, 532 . pp. 29-40. DOI 10.3354/meps11345 <https://doi.org/10.3354/meps11345>. doi:10.3354/meps11345 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3354/meps11345 |
container_title |
Marine Ecology Progress Series |
container_volume |
532 |
container_start_page |
29 |
op_container_end_page |
40 |
_version_ |
1766204188742647808 |