Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints

<p>Photosynthesis in the world's oceans by marine algae is responsible for approximately 50% of CO2 fixed into organic carbon. Aquatic primary producers are intricately linked to the climate system due to their reliance on CO2 as a substrate for photosynthesis and role in the removal and...

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Main Author: Heureux, A
Other Authors: Rickaby, R
Format: Thesis
Language:English
Published: 2016
Subjects:
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author Heureux, A
author2 Rickaby, R
author_facet Rickaby, R
Heureux, A
author_sort Heureux, A
collection OXFORD
description <p>Photosynthesis in the world's oceans by marine algae is responsible for approximately 50% of CO2 fixed into organic carbon. Aquatic primary producers are intricately linked to the climate system due to their reliance on CO2 as a substrate for photosynthesis and role in the removal and export of carbon from the surface ocean to marine sediments. The evolutionary history of marine algae was shaped by changes in the climate system. As a result, fossilized marine algae and modern representatives of ancient groups have the potential to unlock information about the Earth’s climatic past. To use this information and fully understand the role of marine algae in the carbon cycle, however, it is essential to develop an in-depth understanding of CO2 fixation in these organisms. In this thesis I look at carbon fixation in biomineralizing marine algae from a geological and a biological perspective. First I apply a carbon isotope proxy for CO2 to organic material preserved in marine diatom frustules from an extremely transformative period in geological history, the Eocene-Oligocene boundary. Subsequently, this thesis aims to address gaps in our understanding of carbon fixation in eukaryotic marine algae. I present a novel dataset of kinetics of the carbon fixing enzyme, Rubisco, in eukaryotic algae, investigate the role of a pyrenoid-based carbon concentrating mechanism, and identify plastic changes in carbon fixing machinery in response to changing CO2. The findings from this thesis refine our understanding of primary production in the oceans and how we apply algae-based CO2 proxies to understand ancient climates.</p>
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spelling oxford-uuid:eb2b64e5-5740-424b-802e-702c6b88c9372022-03-27T11:07:41ZCarbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprintsThesishttp://purl.org/coar/resource_type/c_db06uuid:eb2b64e5-5740-424b-802e-702c6b88c937Plant SciencesEarth SciencesEnglishOxford University Research Archive - Valet2016Heureux, ARickaby, RLee, R<p>Photosynthesis in the world's oceans by marine algae is responsible for approximately 50% of CO2 fixed into organic carbon. Aquatic primary producers are intricately linked to the climate system due to their reliance on CO2 as a substrate for photosynthesis and role in the removal and export of carbon from the surface ocean to marine sediments. The evolutionary history of marine algae was shaped by changes in the climate system. As a result, fossilized marine algae and modern representatives of ancient groups have the potential to unlock information about the Earth’s climatic past. To use this information and fully understand the role of marine algae in the carbon cycle, however, it is essential to develop an in-depth understanding of CO2 fixation in these organisms. In this thesis I look at carbon fixation in biomineralizing marine algae from a geological and a biological perspective. First I apply a carbon isotope proxy for CO2 to organic material preserved in marine diatom frustules from an extremely transformative period in geological history, the Eocene-Oligocene boundary. Subsequently, this thesis aims to address gaps in our understanding of carbon fixation in eukaryotic marine algae. I present a novel dataset of kinetics of the carbon fixing enzyme, Rubisco, in eukaryotic algae, investigate the role of a pyrenoid-based carbon concentrating mechanism, and identify plastic changes in carbon fixing machinery in response to changing CO2. The findings from this thesis refine our understanding of primary production in the oceans and how we apply algae-based CO2 proxies to understand ancient climates.</p>
spellingShingle Plant Sciences
Earth Sciences
Heureux, A
Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title_full Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title_fullStr Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title_full_unstemmed Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title_short Carbon fixation in eukaryotic marine algae: Evolution of photosynthetic machinery and isotopic footprints
title_sort carbon fixation in eukaryotic marine algae evolution of photosynthetic machinery and isotopic footprints
topic Plant Sciences
Earth Sciences
work_keys_str_mv AT heureuxa carbonfixationineukaryoticmarinealgaeevolutionofphotosyntheticmachineryandisotopicfootprints