dc.contributor.advisor | Laura Meredith and Ron Prinn. | en_US |
dc.contributor.author | Rao, Deepa,Ph.D.Massachusetts Institute of Technology. | en_US |
dc.contributor.other | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences. | en_US |
dc.date.accessioned | 2018-03-27T14:18:46Z | |
dc.date.available | 2018-03-27T14:18:46Z | |
dc.date.copyright | 2012 | en_US |
dc.date.issued | 2012 | en_US |
dc.identifier.uri | http://hdl.handle.net/1721.1/114352 | |
dc.description | Thesis: Ph.D., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2012. | en_US |
dc.description | Cataloged from PDF version of thesis. | en_US |
dc.description | Includes bibliographical references (pages 91-92). | en_US |
dc.description.abstract | Atmospheric hydrogen (H²) is a secondary greenhouse gas that attenuates the removal of methane (CH⁴) from the atmosphere. The largest and least understood term in the H² biogeochemical cycle, microbe-mediated soil uptake, is responsible for about 80% of Earth's tropospheric H² sink. A recent discovery of the first H²-oxidizing soil microorganism (Streptomyces sp. PCB7) containing a low-threshold, high-affinity NiFe-hydrogenase functional at ambient H² levels (approx. 530 ppb) made it possible to identify a model organism to characterize microbial H²-uptake behavior. In the present research, several strains of Streptomyces containing the high-affinity NiFe-hydrogenase were isolated from the Harvard Forest LTER and used to characterize H² uptake alongside analysis of their life cycles. It was found that containing the gene encoding for the specific hydrogenase predicted H² uptake behavior in the wild Streptomyces strains and also in more distantly related organisms that contained the gene. The H² uptake rates were correlated with the microorganisms' life cycles, reaching a maximal uptake corresponding with spore formation. Understanding how environmental conditions, organismal life cycle, and H² uptake are connected can help reduce the uncertainty in atmospheric models. With the rise of H²-based energy sources and a potential change in the tropospheric concentration of H² , understanding the sources and sinks of this trace gas is important for the future. | en_US |
dc.description.statementofresponsibility | by Deepa Rao. | en_US |
dc.format.extent | 92 pages | en_US |
dc.language.iso | eng | en_US |
dc.publisher | Massachusetts Institute of Technology | en_US |
dc.rights | MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. | en_US |
dc.rights.uri | http://dspace.mit.edu/handle/1721.1/7582 | en_US |
dc.subject | Earth, Atmospheric, and Planetary Sciences. | en_US |
dc.title | Exploring the microbe-mediated soil H² sink : a lab-based study of the physiology and related H² consumption of isolates from the Harvard Forest LTER | en_US |
dc.title.alternative | Lab-based study of the physiology and related H² consumption of isolates from the Harvard Forest Long Term Ecological Research. | en_US |
dc.type | Thesis | en_US |
dc.description.degree | S.B. | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences | en_US |
dc.identifier.oclc | 1028979062 | en_US |