{"680758":{"#nid":"680758","#data":{"type":"event","title":"PhD Defense by Claire Elise Elbon","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003Emicrobial usage of diverse electron donors in marine nitrogen loss\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EAnoxic marine systems are key regions of nitrogen loss mediated by anaerobic microbial communities and contribute ~50% of global loss of bioavailable nitrogen to the atmosphere. This dissertation used culture-dependent and culture-independent methods to explore nitrogen loss metabolisms in novel microbial species in two anoxic marine systems: the Eastern Tropical North Pacific oxygen deficient zone and the Orca Basin deep hypersaline anoxic basin in the Gulf of Mexico. Using metagenomics and metatranscriptomics, I found that the most abundantly transcribed nitric oxide dismutase genes in the Eastern Tropical North Pacific oxygen deficient zone belong to a novel order (UBA11136) of Alphaproteobacteria that couple oxidation of one-carbon compounds with aerobic respiration, possibly using oxygen from nitric oxide dismutation. I then isolated and characterized a novel bacterial species, \u003Cem\u003EMarinobacter\u003C\/em\u003E \u003Cem\u003Epacificus\u003C\/em\u003E from the Eastern Tropical North Pacific oxygen deficient zone and characterized the bacterium with epifluorescent microscopy and proteomics. When grown on methane and nitrate, \u003Cem\u003EMarinobacter pacificus\u003C\/em\u003E autofluoresces and highly expresses genes for methanol\/ethanol oxidation and denitrification, a metabolism not previously reported in \u003Cem\u003EMarinobacter\u003C\/em\u003E species. I then enriched\u003Cem\u003E\u0026nbsp;\u003C\/em\u003Ebacterial cultures with methane, manganese, and nitrate as substrates from ~2200 meters at Orca Basin brine-seawater interface. \u003Cem\u003EMarinobacter\u003C\/em\u003E species were dominant, and consumed nitrate while producing manganese oxides. I found previously described chemolithoautotrophic manganese oxidizing bacteria were present and transcriptionally active for manganese oxidation at ~2200 meters as well. Understanding the full breadth of diverse electron acceptors that drive denitrification in anoxic marine systems, where organic carbon is depleted, is essential to understand nitrogen loss in globally important systems.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EMarch 11, 2025, 10 am, Ford ES\u0026amp;T 3235 (Ocean Room) (Hybrid Option via Zoom:\u0026nbsp;\u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/3642802759?omn=95705600401\u0022\u003EClick here\u003C\/a\u003E)\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Jennifer Glass, Ph.D.\u003C\/p\u003E\u003Cp\u003ESchool of Earth and Atmospheric Sciences\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Joel Kostka, PhD\u003C\/p\u003E\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Ameet Pinto, PhD\u003C\/p\u003E\u003Cp\u003ESchool of Civil and Environmental Engineering\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Frank Stewart, PhD\u003C\/p\u003E\u003Cp\u003EDepartment of Microbiology\u003C\/p\u003E\u003Cp\u003E\u0026amp; Cell Biology\u003C\/p\u003E\u003Cp\u003EMontana State University\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Laura Bristow, PhD\u003C\/p\u003E\u003Cp\u003EDepartment of Marine Sciences\u003C\/p\u003E\u003Cp\u003EUniversity of Gothenburg\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003Emicrobial usage of diverse electron donors in marine nitrogen loss\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"MICROBIAL USAGE OF DIVERSE ELECTRON DONORS IN MARINE NITROGEN LOSS"}],"uid":"27707","created_gmt":"2025-02-26 19:16:31","changed_gmt":"2025-02-27 14:24:06","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-03-11T10:00:00-04:00","event_time_end":"2025-03-11T12:00:00-04:00","event_time_end_last":"2025-03-11T12:00:00-04:00","gmt_time_start":"2025-03-11 14:00:00","gmt_time_end":"2025-03-11 16:00:00","gmt_time_end_last":"2025-03-11 16:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Ford ES\u0026T 3235 (Ocean Room)(Hybrid Option via Zoom)","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}