{"489721":{"#nid":"489721","#data":{"type":"news","title":"Study Shows Large Variability in Abundance of Viruses that Infect Ocean Microorganisms","body":[{"value":"\u003Cp\u003EViruses infect more than humans or plants. For microorganisms in the oceans \u2013 including those that capture half of the carbon taken out of the atmosphere every day \u2013 viruses are a major threat. But a paper published January 25 in the journal \u003Cem\u003ENature Microbiology\u003C\/em\u003E shows that there\u2019s much less certainty about the size of these viral populations than scientists had long believed.\u003C\/p\u003E\u003Cp\u003ECollecting and re-examining more than 5,600 estimates of ocean microbial cell and virus populations recorded over the past 25 years, researchers have found that viral populations vary dramatically from location to location, and at differing depths in the sea. The study highlights another source of uncertainty governing climate models and other biogeochemical measures.\u003C\/p\u003E\u003Cp\u003E\u201cWhat was surprising was that there was not a constant relationship, as people had assumed, between the number of microbial cells and the number of viruses,\u201d said \u003Ca href=\u0022http:\/\/www.biology.gatech.edu\/people\/joshua-weitz\u0022\u003EJoshua Weitz\u003C\/a\u003E, an associate professor in the \u003Ca href=\u0022http:\/\/www.biology.gatech.edu\/\u0022\u003ESchool of Biology\u003C\/a\u003E at the Georgia Institute of Technology and one of the paper\u2019s two senior co-authors. \u201cBecause viruses are parasites, it was assumed that their number would vary linearly with the number of microbes. We found that the ratio does not remain constant, but decreases systematically as the number of microbes increases.\u201d\u003C\/p\u003E\u003Cp\u003EThe research, which involved authors from 14 different institutions, was initiated as part of a working group from the National Institute for Mathematical and Biological Synthesis (NIMBioS), which is supported by the National Science Foundation. The research was completed with additional support from the Burroughs Wellcome Fund and the Simons Foundation. The research was co-led by Steven Wilhelm, a professor of microbiology at the University of Tennessee, Knoxville.\u003C\/p\u003E\u003Cp\u003EIn the datasets examined by the researchers, the ratio of viruses to microbes varied from approximately 1 to 1 and 150 to 1 in surface waters, and from 5 to 1 and 75 to 1 in the deeper ocean. For years, scientists had utilized a baseline ratio of 10 to 1 \u2013 ten times more viruses than microbes \u2013 which may not adequately represent conditions in many marine ecosystems.\u003C\/p\u003E\u003Cp\u003E\u201cA marine environment with 100-fold more viruses than microbes may have very different rates of microbial recycling than an environment with far fewer viruses,\u201d said Weitz. \u201cOur study begins to challenge the notion of a uniform ecosystem role for viruses.\u201d\u003C\/p\u003E\u003Cp\u003EA key target for viruses are cyanobacteria \u2013 marine microorganisms that obtain their energy through photosynthesis in a process that takes carbon out of the atmosphere. What happens to the carbon these tiny organisms remove may be determined by whether they are eaten by larger grazing creatures \u2013 or die from viral infections.\u003C\/p\u003E\u003Cp\u003EWhen these cyanobacteria die from infections, their carbon is likely to remain in the top of the water column, where it can nourish other microorganisms. If they are eaten by larger creatures, their carbon is likely to sink into the deeper ocean as the grazers die or excrete the carbon in in their feces.\u003C\/p\u003E\u003Cp\u003E\u201cViruses have a role in shunting some of the carbon away from the deep ocean and keeping it in the surface ocean,\u201d said Wilhelm. \u201cQuantifying the strength of the viral shunt remains a vital issue.\u201d\u003C\/p\u003E\u003Cp\u003EInfluenza and measles come to mind when most people think of viruses, but the bulk of world\u2019s viruses actually infect microorganisms. Estimates suggest that a single liter of seawater typically contain more than ten billion viruses.\u003C\/p\u003E\u003Cp\u003ETo better understand this population, the researchers conducted a meta-analysis of the microbial and virus abundance data that had been collected over multiple decades, including datasets collected by many of the co-authors whose laboratories are based in the United States, Canada and Europe. The data had been obtained using a variety of techniques, including epifluorescence microscopy and flow cytometry.\u003C\/p\u003E\u003Cp\u003EBy combining data collected by 11 different research groups, the researchers created a big picture from many smaller ones. The statistical relationships between viruses and microbial cells, analyzed by first-author Charles Wigington from Georgia Tech and second-author Derek Sonderegger from Northern Arizona University, show the range of variation.\u003C\/p\u003E\u003Cp\u003EThe available data provides information about the abundance of viral particles, not their diversity. Viruses are selective in the microbes they target, meaning the true rates of infection require a renewed focus on virus-microbe infection networks.\u003C\/p\u003E\u003Cp\u003E\u201cFuture research should focus on examining the relationship between ocean microorganisms and viruses at the scale of relevant interactions,\u201d said Weitz, \u201cMore ocean surveys are needed to fill in the many blanks for this critical part of the carbon cycle. Indeed, virus infections of microbes could change the flux of carbon and nutrients on a global scale.\u201d\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis work was supported by National Science Foundation (NSF) grants OCE-1233760 and OCE-1061352, a Career Award at the Scientific Interface from the Burroughs Wellcome Fund and a Simons Foundation SCOPE grant. This work arose from discussions in the Ocean Viral Dynamics working group at the National Institute for Mathematical and Biological Synthesis, an Institute sponsored by the National Science Foundation through NSF Award DBI-1300426, with additional support from The University of Tennessee, Knoxville. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Science Foundation.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Charles H. Wigington, et al., \u201cRe-examination of the relationship between marine virus and microbial cell abundances,\u201d (Nature Microbiology, 2016). \u003Ca href=\u0022http:\/\/dx.doi.org\/10.1038\/nmicrobiol.2015.24\u0022\u003Ehttp:\/\/dx.doi.org\/10.1038\/nmicrobiol.2015.24\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EGeorgia Institute of Technology\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003E177 North Avenue\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EAtlanta, Georgia 30332-0181 USA\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Assistance\u003C\/strong\u003E: John Toon (404-894-6986) (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E).\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter:\u003C\/strong\u003E John Toon\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EMarine microorganisms play a critical role in capturing atmospheric carbon, but a new study finds much less certainty than previously believed about the populations of the viruses that infect these important organisms.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"A new study finds large uncertainty in populations of viruses that infect marine microorganisms."}],"uid":"27303","created_gmt":"2016-01-24 20:50:31","changed_gmt":"2016-10-08 03:20:27","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2016-01-25T00:00:00-05:00","iso_date":"2016-01-25T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"489661":{"id":"489661","type":"image","title":"Community of marine bacteria and viruses","body":null,"created":"1453737600","gmt_created":"2016-01-25 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cyanobacteria","file":{"fid":"204416","name":"ocean-virus5.png","image_path":"\/sites\/default\/files\/images\/ocean-virus5_0.png","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/ocean-virus5_0.png","mime":"image\/png","size":51640,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/ocean-virus5_0.png?itok=sMiWz93n"}},"489711":{"id":"489711","type":"image","title":"Water sampling locations","body":null,"created":"1453737600","gmt_created":"2016-01-25 16:00:00","changed":"1475895245","gmt_changed":"2016-10-08 02:54:05","alt":"Water sampling locations","file":{"fid":"204417","name":"measurement_locations.jpg","image_path":"\/sites\/default\/files\/images\/measurement_locations_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/measurement_locations_0.jpg","mime":"image\/jpeg","size":355810,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/measurement_locations_0.jpg?itok=4n_2M-_G"}}},"media_ids":["489661","489681","489701","489711"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"154","name":"Environment"},{"id":"146","name":"Life Sciences and Biology"},{"id":"135","name":"Research"}],"keywords":[{"id":"138191","name":"go-qbios"},{"id":"11599","name":"Joshua Weitz"},{"id":"169846","name":"marine viruses"},{"id":"13407","name":"Microorganisms"},{"id":"169840","name":"ocean microbes"},{"id":"171595","name":"ocean viruses"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\u003Cp\u003EResearch News\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E(404) 894-6986\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}