Insights into vitamin B₁₂ production, acquisition, and use by marine microbes
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2012. Cataloged from PDF version of thesis. Includes bibliographical references. The distribution and magnitude o...
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ftmit:oai:dspace.mit.edu:1721.1/73797 2023-06-11T04:05:53+02:00 Insights into vitamin B₁₂ production, acquisition, and use by marine microbes Insights into vitamin B twelve production, acquisition, and use by marine microbes Bertrand, Erin Marie Mak A. Saito. Woods Hole Oceanographic Institution. Joint Program in Oceanography Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences 2012 319 p. application/pdf http://hdl.handle.net/1721.1/73797 eng eng Massachusetts Institute of Technology http://hdl.handle.net/1721.1/73797 811039057 M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Joint Program in Oceanography Earth Atmospheric and Planetary Sciences Woods Hole Oceanographic Institution Marine microbiology Biogeochemistry Thesis 2012 ftmit 2023-05-29T08:45:50Z Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2012. Cataloged from PDF version of thesis. Includes bibliographical references. The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the composition of marine microbial communities are thus essential aspects of marine biogeochemistry. Vitamin B₁₂, also known as cobalamin, is a cobalt containing organometallic micronutrient produced by some bacteria and archaea and required by many eukaryotic phytoplankton for methionine biosynthesis and regeneration. Although the potential for vitamin B₁₂ availability to impact primary production and phytoplankton species composition has long been recognized, the lack of molecular-level tools for studying B₁₂ production, use and acquisition has limited inquiry into the role of the vitamin in marine biogeochemical processes. This thesis describes the development of such tools and implements them for the study of B₁₂ dynamics in an Antarctic shelf ecosystem. Nucleic acid probes for B₁₂ biosynthesis genes were designed and used to identify a potentially dominant group of B₁₂ producers in the Ross Sea. The activity of this group was then verified by mass spectrometry-based peptide measurements. Then, possible interconnections between iron and B₁₂ dynamics in this region were identified using field-based bottle incubation experiments and vitamin uptake measurements, showing that iron availability may impact both B₁₂ production and consumption. Changes in diatom proteomes induced by low B₁₂ and low iron availability were then examined and used to identify a novel B₁₂ acquisition protein, CBA1, in diatoms. This represents the first identification of a B₁₂ acquisition protein in eukaryotic phytoplankton. Transcripts encoding CBA 1 were ... Thesis Antarc* Antarctic Ross Sea DSpace@MIT (Massachusetts Institute of Technology) Antarctic Ross Sea |
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DSpace@MIT (Massachusetts Institute of Technology) |
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English |
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Joint Program in Oceanography Earth Atmospheric and Planetary Sciences Woods Hole Oceanographic Institution Marine microbiology Biogeochemistry |
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Joint Program in Oceanography Earth Atmospheric and Planetary Sciences Woods Hole Oceanographic Institution Marine microbiology Biogeochemistry Bertrand, Erin Marie Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
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Joint Program in Oceanography Earth Atmospheric and Planetary Sciences Woods Hole Oceanographic Institution Marine microbiology Biogeochemistry |
description |
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2012. Cataloged from PDF version of thesis. Includes bibliographical references. The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the composition of marine microbial communities are thus essential aspects of marine biogeochemistry. Vitamin B₁₂, also known as cobalamin, is a cobalt containing organometallic micronutrient produced by some bacteria and archaea and required by many eukaryotic phytoplankton for methionine biosynthesis and regeneration. Although the potential for vitamin B₁₂ availability to impact primary production and phytoplankton species composition has long been recognized, the lack of molecular-level tools for studying B₁₂ production, use and acquisition has limited inquiry into the role of the vitamin in marine biogeochemical processes. This thesis describes the development of such tools and implements them for the study of B₁₂ dynamics in an Antarctic shelf ecosystem. Nucleic acid probes for B₁₂ biosynthesis genes were designed and used to identify a potentially dominant group of B₁₂ producers in the Ross Sea. The activity of this group was then verified by mass spectrometry-based peptide measurements. Then, possible interconnections between iron and B₁₂ dynamics in this region were identified using field-based bottle incubation experiments and vitamin uptake measurements, showing that iron availability may impact both B₁₂ production and consumption. Changes in diatom proteomes induced by low B₁₂ and low iron availability were then examined and used to identify a novel B₁₂ acquisition protein, CBA1, in diatoms. This represents the first identification of a B₁₂ acquisition protein in eukaryotic phytoplankton. Transcripts encoding CBA 1 were ... |
author2 |
Mak A. Saito. Woods Hole Oceanographic Institution. Joint Program in Oceanography Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
format |
Thesis |
author |
Bertrand, Erin Marie |
author_facet |
Bertrand, Erin Marie |
author_sort |
Bertrand, Erin Marie |
title |
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
title_short |
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
title_full |
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
title_fullStr |
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
title_full_unstemmed |
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes |
title_sort |
insights into vitamin b₁₂ production, acquisition, and use by marine microbes |
publisher |
Massachusetts Institute of Technology |
publishDate |
2012 |
url |
http://hdl.handle.net/1721.1/73797 |
geographic |
Antarctic Ross Sea |
geographic_facet |
Antarctic Ross Sea |
genre |
Antarc* Antarctic Ross Sea |
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Antarc* Antarctic Ross Sea |
op_relation |
http://hdl.handle.net/1721.1/73797 811039057 |
op_rights |
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 |
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1768377571423027200 |