{"id":13489,"date":"2019-03-14T10:49:01","date_gmt":"2019-03-14T17:49:01","guid":{"rendered":"https:\/\/www.darkenergybiosphere.org\/?post_type=publication&#038;p=13489"},"modified":"2019-04-01T13:32:09","modified_gmt":"2019-04-01T20:32:09","slug":"carbon-fixation-and-energy-metabolisms-of-a-subseafloor-olivine-biofilm","status":"publish","type":"publication","link":"https:\/\/www.darkenergybiosphere.org\/publication\/carbon-fixation-and-energy-metabolisms-of-a-subseafloor-olivine-biofilm\/","title":{"rendered":"Carbon fixation and energy metabolisms of a subseafloor olivine biofilm"},"content":{"rendered":"<p>Earth\u2019s largest aquifer ecosystem resides in igneous oceanic crust, where chemosynthesis and water-rock reactions provide the carbon and energy that support an active deep biosphere. The Calvin Cycle is the predominant carbon fixation pathway in cool, oxic, crust; however, the energy and carbon metabolisms in the deep thermal basaltic aquifer are poorly understood. Anaerobic carbon fixation pathways such as the Wood-Ljungdahl pathway, which uses hydrogen (H<sub>2<\/sub>) and CO<sub>2<\/sub>, may be common in thermal aquifers since water-rock reactions can produce H<sub>2<\/sub>in hydrothermal environments and bicarbonate is abundant in seawater. To test this, we reconstructed the metabolisms of eleven bacterial and archaeal metagenome-assembled genomes from an olivine biofilm obtained from a Juan de Fuca Ridge basaltic aquifer. We found that the dominant carbon fixation pathway was the Wood-Ljungdahl pathway, which was present in seven of the eight bacterial genomes. Anaerobic respiration appears to be driven by sulfate reduction, and one bacterial genome contained a complete nitrogen fixation pathway. This study reveals the potential pathways for carbon and energy flux in the deep anoxic thermal aquifer ecosystem, and suggests that ancient H<sub>2<\/sub>-based chemolithoautotrophy, which once dominated Earth\u2019s early biosphere, may thus remain one of the dominant metabolisms in the suboceanic aquifer today.<\/p>\n","protected":false},"template":"","tags":[],"publication_type":[19],"_links":{"self":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication\/13489"}],"collection":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication"}],"about":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/types\/publication"}],"wp:attachment":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/media?parent=13489"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/tags?post=13489"},{"taxonomy":"publication_type","embeddable":true,"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/publication_type?post=13489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}