{"604355":{"#nid":"604355","#data":{"type":"news","title":"Revisiting Earth\u2019s Oxygenation 2.4 Billion Years Ago","body":[{"value":"\u003Cp\u003EEarth experienced a profound change 2.4 billion years ago. That\u0026#39;s when oxygen, a by-product of photosynthesis, became an important component of its atmosphere.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe earliest photosynthetic organisms were blue-green algae, or cyanobacteria. Their descendants still exist today.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ECyanobacteria emerged billions of years ago, when Earth supported only anaerobic life and before life evolved mechanisms to cope with the toxic effects of reactive forms of oxygen. Abundant iron in ancient oceans exacerbated oxygen\u0026rsquo;s reactivity, making it an even stronger poison.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESo how did ancient cyanobacteria cope with the effects of the toxic by-product of their own metabolism?\u003C\/p\u003E\r\n\r\n\u003Cp\u003EStarting in May, Georgia Tech\u0026rsquo;s Nadia Szeinbaum will pursue that question with a fellowship from the \u003Ca href=\u0022https:\/\/nai.nasa.gov\/funding\/postdoctoral-fellowship-program\/\u0022\u003ENASA Astrobiology Postdoctoral Program\u003C\/a\u003E. She will assemble microbial communities to test the hypothesis that cyanobacteria survived rising oxygen with help from other bacteria.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;Many modern cyanobacteria have limited ability to counter the toxic effects of the oxygen they themselves produce,\u0026rdquo; Szeinbaum says. Instead, they rely on other bacteria that produce catalase, an enzyme that detoxifies oxygen.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;Could it be that this cooperative relationship was what allowed cyanobacteria to succeed and adapt to oxygen billions of years ago?\u0026rdquo; she asks.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ETo address the question, Szeinbaum will create a community of model cyanobacteria and catalase-producing bacteria under conditions of ancient Earth \u0026ndash; with just a bit of oxygen and lots of iron. In this environment, Szeinbaum says, oxygen is highly toxic to cyanobacteria, but not to catalase-producing bacteria.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EIn modern ecosystems, the model organisms typically live apart, but evidence suggests that their ancestors may have helped each other adapt as oxygen rose. Szeinbaum hopes her experiments will yield insights about what happened billions of years ago.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESzeinbaum is a postdoctoral researcher in the labs of \u003Ca href=\u0022http:\/\/jenniferglass.com\/Jennifer_Glass\/Welcome.html\u0022\u003EJennifer Glass\u003C\/a\u003E, \u003Ca href=\u0022http:\/\/reinhard.gatech.edu\/\u0022\u003EChristopher Reinhard\u003C\/a\u003E, and \u003Ca href=\u0022http:\/\/tang.eas.gatech.edu\/\u0022\u003EYuanzhi Tang\u003C\/a\u003E, assistant professors in the School of Earth and Atmospheric Sciences. Born, raised, and educated in Argentina, Szeinbaum came to Georgia Tech to study wastewater treatment.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAfter receiving a master\u0026rsquo;s degree in environmental engineering in 2009, she switched her focus to anaerobic physiology and microbial genetics. She joined the lab of School of Biological Sciences Professor \u003Ca href=\u0022http:\/\/biosci.gatech.edu\/people\/thomas-dichristina\u0022\u003EThomas DiChristina\u003C\/a\u003E and earned a Ph.D. 2014.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESzeinbaum is among many early-career scientists addressing the fundamental questions driving the\u003Ca href=\u0022https:\/\/www.cos.gatech.edu\/hg\/item\/598138\u0022\u003E burgeoning field of astrobiology at Georgia Tech\u003C\/a\u003E:\u0026nbsp;How did life start? Where could life exist outside Earth?\u0026nbsp; Where is life going on Earth and beyond? How would we recognize life outside of Earth?\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe conditions of early Earth could be similar to current conditions in potentially habitable bodies in the universe, Szeinbaum says. \u0026ldquo;Understanding what forms of life may have existed in the past can help us understand whether life exists somewhere else.\u0026rdquo;\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"With a NASA Astrobiology Postdoctoral Fellowship, Nadia Szeinbaum will go back in time "}],"field_summary":[{"value":"\u003Cp\u003EThe first photosynthetic organisms, cyanobacteria, emerged billions of years ago, when Earth supported only anaerobic life and before life evolved mechanisms to cope with the toxic effects of reactive forms of oxygen. Abundant iron in ancient oceans exacerbated oxygen\u0026rsquo;s reactivity, making it an even stronger poison.\u0026nbsp;So how did ancient cyanobacteria cope with the effects of the toxic by-product of their own metabolism?\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Nadia Szeinbaum will assemble microbial communities to test the hypothesis that the first photosynthetic organisms survived the toxic effects of oxygen with help from other bacteria."}],"uid":"30678","created_gmt":"2018-03-27 21:39:29","changed_gmt":"2018-03-28 14:59:29","author":"A. Maureen Rouhi","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2018-03-28T00:00:00-04:00","iso_date":"2018-03-28T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"604354":{"id":"604354","type":"image","title":"Nadia Szeinbaum","body":null,"created":"1522185664","gmt_created":"2018-03-27 21:21:04","changed":"1522185664","gmt_changed":"2018-03-27 21:21:04","alt":"","file":{"fid":"230360","name":"2018 Nadia Szeinbaum.square250.jpg","image_path":"\/sites\/default\/files\/images\/2018%20Nadia%20Szeinbaum.square250.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/2018%20Nadia%20Szeinbaum.square250.jpg","mime":"image\/jpeg","size":48713,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/2018%20Nadia%20Szeinbaum.square250.jpg?itok=W2HTDjrs"}}},"media_ids":["604354"],"related_links":[{"url":"https:\/\/www.cos.gatech.edu\/hg\/item\/598138","title":"Astrobiology Rising at Georgia Tech"}],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"364801","name":"EAS"}],"categories":[{"id":"146","name":"Life Sciences and Biology"}],"keywords":[{"id":"177530","name":"Nadia Szeinbaum"},{"id":"79441","name":"jennifer glass"},{"id":"170504","name":"Chris Reinhard"},{"id":"175754","name":"Yuanzhi Tang"},{"id":"177531","name":"Thomas DiChristina"},{"id":"173096","name":"cyanobacteria"},{"id":"177532","name":"Earth\u0027s oxygenation"},{"id":"4896","name":"College of Sciences"},{"id":"166926","name":"School of Earth and Atmospheric Sciences"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EA. Maureen Rouhi, Ph.D.\u003Cbr \/\u003E\r\nDirector of Communications\u003Cbr \/\u003E\r\nCollege of Sciences\u003C\/p\u003E\r\n","format":"limited_html"}],"email":["maureen.rouhi@cos.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}