Show simple item record

dc.contributor.advisorHarvey, Henry Ren_US
dc.contributor.authorFaux, Jessica Feliciaen_US
dc.date.accessioned2014-06-24T06:06:35Z
dc.date.available2014-06-24T06:06:35Z
dc.date.issued2014en_US
dc.identifier.urihttp://hdl.handle.net/1903/15308
dc.description.abstractThe response of global carbon and nitrogen cycles to future climate change is uncertain. In order to understand the impacts that future changes to climate will have on these cycles, a more detailed understanding of them is essential. This dissertation utilizes a combined approach of molecular biomarkers and proteomic investigations to elucidate historic source material contributions and microbial protein production to contribute to a more thorough understanding of the marine carbon and nitrogen cycles. The examination of molecular organic biomarkers throughout an Arctic sediment core showed the dominant input in the area was from marine sources with lower but steady contributions from terrestrial sources during the Holocene. Attempts to recover proteins from deeper sediments to correlate with lipid biomarkers were unsuccessful but led to the optimization of an extraction protocol for an added protein standard, bovine serum albumin, from sediments. An investigation into the expressed proteome of the heterotrophic marine bacterium, <italic>Ruegeria pomeroyi</italic>, under environmentally realistic carbon supply conditions during exponential and stationary growth phases identified over 2000 proteins. The most abundant proteins identified were responsible for porins, transport, binding, translation, and protein refolding and could represent potential biomarkers of bacterial processes and/or activity. A parallel study of <italic>R. pomeroyi</italic>, in which <super>13</super>C-labeled leucine was added to the culture during exponential growth phase, showed labeled incorporation ranging from 16 to 21% of the total proteins produced depending on growth phase. The widespread distribution of the label among the growth phases indicates active recycling by the bacteria. This study demonstrates a method through which bacterial protein synthesis can be tracked. A study of the marine diatom <italic>Thalassiosira pseudonana</italic> acclimated to iron replete or iron-limited conditions showed iron-limited organisms increased proteins involved in pathways associated with intracellular protein recycling, the pentose phosphate pathway, lower photosynthetic energy production, enhancement of photorespiration, and increased polysaccharide production. This application of proteomics to the examination of proteins in marine sediments, a marine diatom, and a heterotrophic marine bacterium shows the potential for these techniques to help elucidate the fate of proteins in marine environments and could be used in conjunction with well-established molecular organic marker studies.en_US
dc.language.isoenen_US
dc.titleA Proteomics Approach to the Examination of Proteins in Marine Systemsen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentMarine-Estuarine-Environmental Sciencesen_US
dc.subject.pqcontrolledChemical oceanographyen_US
dc.subject.pquncontrolledArcticen_US
dc.subject.pquncontrolledBacteriaen_US
dc.subject.pquncontrolledMarineen_US
dc.subject.pquncontrolledProteinsen_US
dc.subject.pquncontrolledProteomicsen_US
dc.subject.pquncontrolledSedimentsen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record