Project description:The available energy and carbon sources for prokaryotes in the deep ocean remain still largely enigmatic. Reduced sulfur compounds, such as thiosulfate, are a potential energy source for both auto- and heterotrophic marine prokaryotes. Shipboard experiments performed in the North Atlantic using Labrador Sea Water (~2000 m depth) amended with thiosulfate led to an enhanced prokaryotic dissolved inorganic carbon (DIC) fixation.
Project description:The diazotroph Trichodesmium is an important contributor to marine dinitrogen (N2) fixation, supplying so-called new N to phytoplankton in typically N-limited ocean regions. Identifying how iron (Fe) and phosphorus (P) influence Trichodesmium activity and biogeography is an ongoing area of study, where predicting patterns of resource stress is complicated in part by the uncertain bioavailability of organically complexed Fe and P. Here, a comparison of 26 metaproteomes from picked Trichodesmium colonies identified significantly different patterns between three ocean regions: the western tropical South Pacific, the western North Atlantic, and the North Pacific Subtropical Gyre. Trichodesmium metaproteomes across these regions significantly differed in KEGG submodule signals, and vector fitting showed that dissolved Fe, phosphate, and temperature significantly correlated with regional proteome patterns. Populations in the western tropical South Pacific appeared to modulate their proteomes in response to both Fe and P stress, including a comparatively low relative abundance of the N2 fixation marker protein, NifH. Significant increases in the relative abundance of both Fe and P stress marker proteins previously validated in culture studies suggested that Trichodesmium populations in the western North Atlantic and North Pacific were P-stressed and Fe-stressed, respectively. These patterns recapitulate established regional serial and co-limitation patterns of resource stress on phytoplankton communities. Evaluating community stress patterns may therefore predict resource controls on diazotroph biogeography. These data highlight how Trichodesmium modulates its metabolism in the field and provide an opportunity to more accurately constrain controls on Trichodesmium biogeography and N2 fixation.
Project description:This project presents field metaproteomics data from Trichodesmium colonies collected from the surface ocean. Most were collected from the tropical and subtropical Atlantic ocean, but there is also data from the long term Bermuda Atlantic Time Series and Hawaii Ocean Time Series. Trichodesmium is a globally important marine microbe and its growth and nitrogen fixation activity is limited by nutrient availability in the surface ocean. This dataset was generated to answer questions about limitations on Trichodesmium's growth and activity in the nature.
Project description:An Autonomous Underwater Vehicle (AUV) and large volume underwater pumps were used to collect microbial biomass from offshore waters of the Sargasso Sea, from surface waters and into the deep ocean. Seawater collection was performed along a transect in the western North Atlantic Ocean beginning near Bermuda and ending off the coast of Massachusetts, capturing metabolic signatures from oligotrophic, continental margin, and productive coastal ecosystems.
Project description:Metaproteomics is an increasingly popular methodology that provides information regarding the metabolic functions of specific microbial taxa and can be used to assess environmental stressors and change and has potential for contributing to ocean ecology and biogeochemical studies. To enable future large-scale studies, a multi-laboratory intercomparison was conducted to assess comparability and reproducibility of taxonomic and functional results and their sensitivity to methodological variables. This ocean metaproteomic intercomparison consisted of two major activities: a laboratory component, where independent labs processed identical ocean samples simultaneously collected from the North Atlantic Ocean , and a subsequent informatic component.
Project description:Metaproteomics is an increasingly popular methodology that provides information regarding the metabolic functions of specific microbial taxa and can be used to assess environmental stressors and change and has potential for contributing to ocean ecology and biogeochemical studies. To enable future large-scale studies, a multi-laboratory intercomparison was conducted to assess comparability and reproducibility of taxonomic and functional results and their sensitivity to methodological variables. This ocean metaproteomic intercomparison consisted of two major activities: a laboratory component, where independent labs processed identical ocean samples simultaneously collected from the North Atlantic Ocean , and a subsequent informatic component.
Project description:Marine dissolved organic matter from the Atlantic Ocean. Samples were analyzed by LC-MS/MS in positive and negative electrospray ionization mode using DDA (Orbitrap Eclipse).