The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters
Biological N2 fixation constitutes the major source of nitrogen in open ocean systems, regulating the marine nitrogen inventory and primary productivity. Symbiotic relationships between phytoplankton and N2 fixing microorganisms (diazotrophs) have been suggested to play a significant role in the eco...
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Universität Bremen
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/568 2023-05-15T17:36:27+02:00 The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters Die Rolle einzelliger Cyanobakterien in der Fixierung und Assimilierung von atmosphärischem Stickstoffgas in subtropischen marinen Gewässern Krupke, Andreas Kuypers, Marcel Fuchs, Bernhard 2013-10-02 application/pdf https://media.suub.uni-bremen.de/handle/elib/568 https://nbn-resolving.org/urn:nbn:de:gbv:46-00103481-13 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/568 urn:nbn:de:gbv:46-00103481-13 info:eu-repo/semantics/openAccess UCYN-A Haptophyta symbiosis single-cell analysis nanoSIMS oligotrophic open ocean 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2013 ftsubbremen 2022-11-09T07:09:23Z Biological N2 fixation constitutes the major source of nitrogen in open ocean systems, regulating the marine nitrogen inventory and primary productivity. Symbiotic relationships between phytoplankton and N2 fixing microorganisms (diazotrophs) have been suggested to play a significant role in the ecology and biogeochemistry in these oceanic regions. The widely distributed, uncultured N2 fixing cyanobacterium UCYN A was suggested to live in symbiosis since it has unprecedented genome reduction, including the lack of genes encoding for oxygen evolving photosystem II and the tricarboxylic acid cycle. This thesis aims to study carbon and nitrogen metabolism on field populations of UCYN A using molecular biology, as well as mass spectrometry tools to visualize metabolic activity on a single cell scale. The development of a 16S rRNA oligonucleotide probe specifically targeting UCYN A cells and its successful application on environmental samples (Manuscript I and II) revealed a symbiotic partnership with a unicellular prymnesiophyte. We demonstrated a nutrient transfer in carbon and nitrogen compounds between these two partner cells, providing an explanation how these diazotrophs thrive in open ocean systems. Further, UCYN A can also associate with globally abundant calcifying prymnesiophyte members, e.g. Braarudosphaera bigelowii, indicating that this symbiosis might impact the efficiency of the biological carbon pump. In manuscript III, we provided quantitative information on the cellular abundance and distribution of UCYN A cells in the North Atlantic Ocean and identified the eukaryotic partner cell as Haptophyta (including prymnesiophyte) via double Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD FISH). The UCYN A Haptophyta association was the dominant form (87.0±6.1%) over free living UCYN A cells. Interestingly, we also detected UCYN A cells living in association with unknown eukaryotes and non calcifying Haptophyta cells, raising questions about the host specificity. During a follow up ... Doctoral or Postdoctoral Thesis North Atlantic Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
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Open Polar |
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Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
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ftsubbremen |
language |
English |
topic |
UCYN-A Haptophyta symbiosis single-cell analysis nanoSIMS oligotrophic open ocean 550 550 Earth sciences and geology ddc:550 |
spellingShingle |
UCYN-A Haptophyta symbiosis single-cell analysis nanoSIMS oligotrophic open ocean 550 550 Earth sciences and geology ddc:550 Krupke, Andreas The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
topic_facet |
UCYN-A Haptophyta symbiosis single-cell analysis nanoSIMS oligotrophic open ocean 550 550 Earth sciences and geology ddc:550 |
description |
Biological N2 fixation constitutes the major source of nitrogen in open ocean systems, regulating the marine nitrogen inventory and primary productivity. Symbiotic relationships between phytoplankton and N2 fixing microorganisms (diazotrophs) have been suggested to play a significant role in the ecology and biogeochemistry in these oceanic regions. The widely distributed, uncultured N2 fixing cyanobacterium UCYN A was suggested to live in symbiosis since it has unprecedented genome reduction, including the lack of genes encoding for oxygen evolving photosystem II and the tricarboxylic acid cycle. This thesis aims to study carbon and nitrogen metabolism on field populations of UCYN A using molecular biology, as well as mass spectrometry tools to visualize metabolic activity on a single cell scale. The development of a 16S rRNA oligonucleotide probe specifically targeting UCYN A cells and its successful application on environmental samples (Manuscript I and II) revealed a symbiotic partnership with a unicellular prymnesiophyte. We demonstrated a nutrient transfer in carbon and nitrogen compounds between these two partner cells, providing an explanation how these diazotrophs thrive in open ocean systems. Further, UCYN A can also associate with globally abundant calcifying prymnesiophyte members, e.g. Braarudosphaera bigelowii, indicating that this symbiosis might impact the efficiency of the biological carbon pump. In manuscript III, we provided quantitative information on the cellular abundance and distribution of UCYN A cells in the North Atlantic Ocean and identified the eukaryotic partner cell as Haptophyta (including prymnesiophyte) via double Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD FISH). The UCYN A Haptophyta association was the dominant form (87.0±6.1%) over free living UCYN A cells. Interestingly, we also detected UCYN A cells living in association with unknown eukaryotes and non calcifying Haptophyta cells, raising questions about the host specificity. During a follow up ... |
author2 |
Kuypers, Marcel Fuchs, Bernhard |
format |
Doctoral or Postdoctoral Thesis |
author |
Krupke, Andreas |
author_facet |
Krupke, Andreas |
author_sort |
Krupke, Andreas |
title |
The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
title_short |
The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
title_full |
The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
title_fullStr |
The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
title_full_unstemmed |
The role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
title_sort |
role of unicellular cyanobacteria in nitrogen fixation and assimilation in subtropical marine waters |
publisher |
Universität Bremen |
publishDate |
2013 |
url |
https://media.suub.uni-bremen.de/handle/elib/568 https://nbn-resolving.org/urn:nbn:de:gbv:46-00103481-13 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/568 urn:nbn:de:gbv:46-00103481-13 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766135930246135808 |