Formation of authigenic minerals during microbial degradation in artificial marine media
Thesis: S.M. in Geobiology, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2015.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2016
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| Online Access: | http://hdl.handle.net/1721.1/101345 |
| _version_ | 1811095006955438080 |
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| author | Joss, Matthew Albert Henry |
| author2 | Tanja Bosak and Daniel Rothman. |
| author_facet | Tanja Bosak and Daniel Rothman. Joss, Matthew Albert Henry |
| author_sort | Joss, Matthew Albert Henry |
| collection | MIT |
| description | Thesis: S.M. in Geobiology, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2015. |
| first_indexed | 2024-09-23T16:09:02Z |
| format | Thesis |
| id | mit-1721.1/101345 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T16:09:02Z |
| publishDate | 2016 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1013452019-04-12T09:36:34Z Formation of authigenic minerals during microbial degradation in artificial marine media Joss, Matthew Albert Henry Tanja Bosak and Daniel Rothman. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. Earth, Atmospheric, and Planetary Sciences. Thesis: S.M. in Geobiology, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2015. Cataloged from PDF version of thesis. Includes bibliographical references (pages 73-74). I have conducted incubation experiments exploring microbial degradation of organic matter within an artificial sediment designed to simulate an organic-rich siliciclastic marine sediment. Central questions to my research include: 1) How does the presence of dissolved iron influence the degradation and/or protection of organic matter within sediments? 2) How does dissolved iron influence the development of authigenic minerals? 3) How do microbial metabolisms affect dissolved iron concentrations and authigenic mineral precipitation? My experimental system consisted of dead cyanobacterial cells that were mixed with acid-washed glass beads, thereby making an artificial sediment essentially free of contaminants. This material was deposited into incubation cultures with artificial marine liquid media with varying concentrations of dissolved Fe(III). The cultures were exposed either to a natural sediment community or to the iron-reducing facultative anaerobe Shewanella Putrefaciens, in oxia or in anoxia. These cultures were compared against controls that contained no living microbes. The liquid media had varying initial concentrations of dissolved iron. For cultures with initially 0.2 mg/L of dissolved Fe(III) or no initial dissolved Fe(III), I measure the extent of degradation through loss on ignition gravimetry after 40 days of incubation. I also measured pH levels, dissolved Fe(II), and total Fe over a period of 60 days. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to identify mineralized organic particles and mineral grains within subsamples of the living cultures. In contrast, the sterile controls had no recognizable mineralization present. Finally, X-ray diffraction spectra were obtained for sediment subsamples of cultures with initial iron concentrations of 0.1 mg/L, revealing spectral peaks indicative of small amounts of authigenic mineral structure present within the oxic living cultures. Iron is identified as a key component of many mineralized structures within the living samples, particularly in the anoxic samples, with iron rich particles usually being mostly amorphous. It is possible that longer incubation times would increase the extent of mineralization and produce divergent rates of organic matter protection and degradation. by . S.M. in Geobiology 2016-02-29T15:01:42Z 2016-02-29T15:01:42Z 2015 2015 Thesis http://hdl.handle.net/1721.1/101345 938903070 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 74 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Earth, Atmospheric, and Planetary Sciences. Joss, Matthew Albert Henry Formation of authigenic minerals during microbial degradation in artificial marine media |
| title | Formation of authigenic minerals during microbial degradation in artificial marine media |
| title_full | Formation of authigenic minerals during microbial degradation in artificial marine media |
| title_fullStr | Formation of authigenic minerals during microbial degradation in artificial marine media |
| title_full_unstemmed | Formation of authigenic minerals during microbial degradation in artificial marine media |
| title_short | Formation of authigenic minerals during microbial degradation in artificial marine media |
| title_sort | formation of authigenic minerals during microbial degradation in artificial marine media |
| topic | Earth, Atmospheric, and Planetary Sciences. |
| url | http://hdl.handle.net/1721.1/101345 |
| work_keys_str_mv | AT jossmatthewalberthenry formationofauthigenicmineralsduringmicrobialdegradationinartificialmarinemedia |