ubiquitous dissolved inorganic carbon assimilation by marine bacteria in the pacific northwest coastal ocean as determined by stable isotope probing无处不在的溶解无机碳同化的海洋细菌在太平洋西北部沿海海洋由稳定同位素探测.pdf

Ubiquitous Dissolved Inorganic Carbon Assimilation by Marine Bacteria in the Pacific Northwest Coastal Ocean as Determined by Stable Isotope Probing 1 ¨ 1,2 1 1 1 Suzanne DeLorenzo *, Suzanna L. Brauer , Chelsea A. Edgmont , Lydie Herfort , Bradley M. Tebo , Peter Zuber1 1 Center for Coastal Margin Observation Prediction and Division of Environmental Biomolecular Systems, Oregon Health Science University, Beaverton, Oregon, United States of America, 2 Appalachian State University, Rankin Science South, Boone, North Carolina, United States of America Abstract In order to identify bacteria that assimilate dissolved inorganic carbon (DIC) in the northeast Pacific Ocean, stable isotope probing (SIP) experiments were conducted on water collected from 3 different sites off the Oregon and Washington coasts in May 2010, and one site off the Oregon Coast in September 2008 and March 2009. Samples were incubated in the dark with 2 mM 13C-NaHCO , doubling the average concentration of DIC typically found in the ocean. Our results revealed 3 a surprising diversity of marine bacteria actively assimilating DIC in the dark within the Pacific Northwest coastal waters, indicating that DIC fixation is relevant for the metabolism of different marine bacterial lineages, including putatively heterotrophic taxa. Furthermore, dark DIC-assimilating assemblages were widespread among diverse bacterial classes. Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes dominated the active DIC-assimilating communities across the samples. Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Planctomycetes, and Verrucomicrobia were also