Iron limitation and the role of Siderophores in marine Synechococcus
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2009.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2009
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| Online Access: | http://hdl.handle.net/1721.1/46815 |
| _version_ | 1826205481635414016 |
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| author | Rivers, Adam R. (Adam Reid) |
| author2 | Eric A. Webb. |
| author_facet | Eric A. Webb. Rivers, Adam R. (Adam Reid) |
| author_sort | Rivers, Adam R. (Adam Reid) |
| collection | MIT |
| description | Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2009. |
| first_indexed | 2024-09-23T13:13:32Z |
| format | Thesis |
| id | mit-1721.1/46815 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T13:13:32Z |
| publishDate | 2009 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/468152022-01-14T19:35:48Z Iron limitation and the role of Siderophores in marine Synechococcus Rivers, Adam R. (Adam Reid) Eric A. Webb. Woods Hole Oceanographic Institution. Joint Program in Oceanography Woods Hole Oceanographic Institution Massachusetts Institute of Technology. Department of Biology Biology. Joint Program in Oceanography. Woods Hole Oceanographic Institution. Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2009. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. "June 2009." Includes bibliographical references. Marine cyanobacteria in the genus Synechococcus are widely distributed and contribute significantly to global primary productivity. In many parts of the ocean their growth is limited by a lack of iron, an essential nutrient that is virtually insoluble in seawater. To overcome this, Synechococcus have evolved a number of strategies to acquire iron. Gene distribution, metagenomics and a novel immunological flow cytometry assay in the Costa Rica Upwelling Dome were used to estimate the importance of Fe stress. Genomic and metagenomic measures suggest that iron limitation is, paradoxically, more severe in coastal and upwelling areas than in the open ocean, where iron is less abundant. A serological assay found significant differences in the vertical distribution of the Fe stress protein IdiA over just a few meters. Despite average surface ocean iron concentrations of just 0.07 nM, most marine oligotrophic cyanobacteria lack iron-binding siderophores that are present in many heterotrophic marine bacteria. Siderophores are widely distributed in the surface ocean and compose an important portion of the pool of natural ligands that bind >99% of all soluble Fe. In bottle incubations from the Sargasso Sea we found the addition of Fe complexed to an excess of the siderophore desferrioxamine B (DFB) limited Synechococcus growth and stimulated the growth of heterotrophic bacteria in a concentration dependent manner. (cont.) Laboratory work revealed that excess DFB decreased Synechococcus growth beyond Fe-limited controls at concentrations as low as 20-40 nM. The inhibition was aggravated by light but it could be reversed by the addition of Fe. The DFB inhibition could not be explained by thermodynamic or kinetic models of Fe' or co-limitation with other metals. DFB may interact with some aspect of cellular physiology to directly inhibit cyanobacterial growth. by Adam R. Rivers. Ph.D. 2009-09-24T20:49:47Z 2009-09-24T20:49:47Z 2009 Thesis http://hdl.handle.net/1721.1/46815 435438688 eng 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 102 p. application/pdf Massachusetts Institute of Technology |
| spellingShingle | Biology. Joint Program in Oceanography. Woods Hole Oceanographic Institution. Rivers, Adam R. (Adam Reid) Iron limitation and the role of Siderophores in marine Synechococcus |
| title | Iron limitation and the role of Siderophores in marine Synechococcus |
| title_full | Iron limitation and the role of Siderophores in marine Synechococcus |
| title_fullStr | Iron limitation and the role of Siderophores in marine Synechococcus |
| title_full_unstemmed | Iron limitation and the role of Siderophores in marine Synechococcus |
| title_short | Iron limitation and the role of Siderophores in marine Synechococcus |
| title_sort | iron limitation and the role of siderophores in marine synechococcus |
| topic | Biology. Joint Program in Oceanography. Woods Hole Oceanographic Institution. |
| url | http://hdl.handle.net/1721.1/46815 |
| work_keys_str_mv | AT riversadamradamreid ironlimitationandtheroleofsiderophoresinmarinesynechococcus |