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 experiment compared flounder from the North Sea and the Baltic sea and their reactions on being exposed to water of different salinities
Project description:Vibrio species represent one of the most diverse genera of marine bacteria known for their ubiquitous presence in natural aquatic systems. Several members of this genus including Vibrio harveyi are receiving increasing attention lately because they are becoming a source of health problems, especially for some marine organisms widely used in sea food industry. To learn about adaptation changes triggered by V. harveyi during its long-term persistence at elevated temperatures, we studied adaptation of this marine bacterium in sea water microcosms at 30 oC that closely mimicks the upper limits of sea surface temperatures recorded around the globe.
Project description:In this project, the metaproteome of the marine bacterioplankton was analyzed to assess its respone towards an algal bloom in the southern North Sea in spring 2010. Proteins were extracted applying two different methods: (i) applying chemical cell lysis using trifluoroethanol in combination with in-solution digest and (ii) mechanical cell lysis applying bead beating, SDS-PAGE prefractionation and in-gel digest. Both samples were analyzed by nanoLC and ESI-iontrap MS. In case of the TFE lysis samples, also nanoLC-MALDI-TOF MS was applied.
Project description:Marine microalgae (phytoplankton) mediate almost half of the worldwide photosynthetic carbon dioxide fixation and therefore play a pivotal role in global carbon cycling, most prominently during massive phytoplankton blooms. Phytoplankton biomass consists of considerable proportions of polysaccharides, substantial parts of which are rapidly remineralized by heterotrophic bacteria. We analyzed the diversity, activity and functional potential of such polysaccharide-degrading bacteria in different size fractions during a diverse spring phytoplankton bloom at Helgoland Roads (southern North Sea) at high temporal resolution using microscopic, physicochemical, biodiversity, metagenome and metaproteome analyses.
Project description:About one half of the global, biogenic carbon dioxide fixation into organic matter is driven by microscopic algae in the surface oceans. These microalgal activities generate, among other molecules, polysaccharides that are food for and recycled by bacteria with polysaccharide utilization loci (PULs). These genetic clusters of co-evolved genes, which work together in recognition, depolymerizing and uptake of one type of polysaccharide. However, we rarely know the substrates of PULs present in marine bacteria. Here we investigated the proteomic and physiological response of mannan PULs from marine Flavobacteriia isolated in the North Sea. The genomic clusters of these marine Bacteroidetes are related to PULs of human gut Bacteroides strains, which are known to digest α- and β-mannans from yeasts and plants respectively. Proteomics and defined growth experiments with these types of mannans as sole carbon source confirmed the functional prediction. Our data suggest that biochemical principles established for gut or terrestrial microbes apply to marine bacteria even though the PULs are evolutionary distant. Moreover, our data support discoveries from the 60th reporting mannans in microalgae suggesting that these polysaccharides play an important role in the marine carbon cycle.
Project description:About one half of the global, biogenic carbon dioxide fixation into organic matter is driven by microscopic algae in the surface oceans. These microalgal activities generate, among other molecules, polysaccharides that are food for and recycled by bacteria with polysaccharide utilization loci (PULs). These genetic clusters of co-evolved genes, which work together in recognition, depolymerizing and uptake of one type of polysaccharide. However, we rarely know the substrates of PULs present in marine bacteria. Here we investigated the proteomic and physiological response of mannan PULs from marine Flavobacteriia isolated in the North Sea. The genomic clusters of these marine Bacteroidetes are related to PULs of human gut Bacteroides strains, which are known to digest α- and β-mannans from yeasts and plants respectively. Proteomics and defined growth experiments with these types of mannans as sole carbon source confirmed the functional prediction. Our data suggest that biochemical principles established for gut or terrestrial microbes apply to marine bacteria even though the PULs are evolutionary distant. Moreover, our data support discoveries from the 60th reporting mannans in microalgae suggesting that these polysaccharides play an important role in the marine carbon cycle.
Project description:Marine algae convert a substantial fraction of the carbon dioxide they fix into various polysaccharides. Bacteria specialized on the remineralization of these polysaccharides often feature genomic clusters, termed polysaccharide utilization loci (PULs). Such PULs are often prevalent in, but not limited to, marine Flavobacteriia. Since knowledge on extant PUL diversity is sparse, we sequenced the genomes of 53 North Sea Flavobacteriia. We obtained 400 PULs, suggesting usage of a large array of polysaccharides, including laminarin, α- and β-mannans, fucose-, xylose-, galactose-, rhamnose- and arabinose-containing substrates, pectins, and chitins. Many of the PULs were novel, some indicating substrates that have rarely been described in marine environments. PUL repertoires of isolates often differed significantly within genera, corroborating ecological niche-associated glycan partitioning. Polysaccharide uptake in Flavobacteriia is mediated by SusCD. Respective protein trees revealed clustering according to polysaccharide specificities. Analysis of SusCD expression in multiyear phytoplankton bloom-associated metaproteomes indicated changes in microbial utilization of glucan, ß-mannan and sulfated xylan, suggesting that distinct substrates are temporarily abundant.
2018-08-16 | PXD008238 | Pride
Project description:Sea semester samples 2020 - optimizing marine eDNA sampling at sea towards standardized marine biodiversity surveys
Project description:In this study, transcriptomics was used to investigate Atlantic salmon (Salmo salar) sampled from three different field locations within Baltic Sea (Baltic Main Basin (CBS), Gulf of Finland (GoF) and Bothnian Sea (BS)) during marine migration. RNA labeling, hybridizations, and scanning were performed by the Finnish Microarray and Sequencing Centre in Turku Centre for Biotechnology.