We analysed the monosaccharide composition in high molecular weight dissolved organic matter (HMWDOM) during a three month diatom bloom period in the North Sea (54˚11.3'N, 7˚54.0'E). HMWDOM samples were concentrated by tangential flow filtration (TFF). These were hydrolysed with acid into monomers and quantified by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD).
Details describing the data:
A total of 19 samples were analysed including two technical replicates. Each sample corresponds to 100 L of 0.2 μm-filtered seawater that were concentrated to a final volume of 0.5 L by TFF with 1 kDa cassettes. Therefore samples contain the size fraction between 0.2 µm and 1 kDa. The TFF-concentrated HMWDOM samples were analysed and data show their monosaccharide composition as mean relative abundance (in molarity).
Here, we traced the abundance of 27 polysaccharide epitopes in dissolved and particulate organic matter along a three month diatom bloom period in the North Sea. We used a bioanalytic approach based on carbohydrate microarrays and monoclonal antibodies (mAbs).
Details describing the data:
Carbohydrate microarray data show the relative polysaccharide abundance (antibody signal intensity) detected in samples harvested during a spring phytoplankton bloom period (21 sampling dates) in the North Sea (54˚11.3'N, 7˚54.0'E). Samples include high molecular weight dissolved organic matter (HMWDOM) and particulate organic matter (POM). Polysaccharides from all samples were sequentially extracted with the solvents H2O, 50 mM EDTA pH 7.5 and 4 M NaOH with 0.1% w/v NaBH4. A library of identical microarrays was created, each populated with the same time-series of extracted polysaccharides. These microarrays were then individually incubated with polysaccharide-specific mAbs or carbohydrate binding modules (CBMs) as probes, which specifically bind to a single polysaccharide epitope. The binding of probes to polysaccharide epitopes on the microarrays was detected using a secondary antibody coupled to alkaline phosphatase, which converts its substrate into a coloured product, the amount of which correlates with polysaccharide concentration. Antibody signal intensity was quantified and the highest signal value in the data set for HMWDOM and for POM was set to 100 and all other values were normalised accordingly. The temporal dynamics but not the absolute number should be compared between HMWDOM and POM pools as they required independent normalisation since their sampling was different. A cut-off of 5 arbitrary units was applied and all probe profiles where in at least one date an antibody positive signal (value ≥ 5) was detected are included in the data set. The epitope recognised by each probe is shown at the top of each column and the name of the corresponding mAb or CBM is depicted in parentheses. Size fractions correspond to: POM 10 µm, over 10 µm; POM 3 µm, between 10 and 3 µm; POM 0.2 µm, between 3 and 0.2 µm; HMWDOM, between 0.2 µm and 1 kDa. HG, homogalacturonan; DE, degree of esterification; AGP, arabinogalactan protein; GlcA, glucuronic acid. This microarray data set reveals the temporal dynamics of 27 polysaccharide epitopes in HMWDOM and POM.
High molecular weight dissolved organic matter (HMWDOM) and particulate organic matter (POM) samples were harvested during a spring phytoplankton bloom period in the North Sea for about three months. Polysaccharides from all HMWDOM and POM samples were extracted and analysed by carbohydrate microarray analysis. Additionally, glycans in the HMWDOM samples were also studied by monosaccharide analysis.
During the first five years of the IGBP Work Plan of 1994-1998, the Joint Global Ocean Flux Study (JGOFS) goals were aimed at understanding the biogeochemical processes affecting the time-varying fluxes of carbon and associated elements within the ocean and across its boundaries. The primary objective is to assess more accurately and to understand better the processes controlling regional-global and seasonal-interannual fluxes of carbon between the atmosphere and the upper ocean, the ocean interior in order to assess their sensitivity to climate forcing and change. By the end of 1998, most JGOFS field programs will have been achieved, which are now reported in various scientific products. Southern Ocean JGOFS e.g. has published 3 Special Issues of Deep-Sea Research besides various articles in Nature and other scientific journals. The diverse JGOFS ocean data sets are comprised of biological, chemical and physical observations, according to standard protocols for the JGOFS core measurements (Report No. 19), and are being managed and archived by many large national programs and subsets of these large diverse data sets are provided to all scientists in the form of CD-ROMs and off the Internet. Initial biogeochemical models are being developed and evaluated, which reflect our basic understanding of the processes controlling carbon fluxes (see JGOFS Report Nos. 23 and 24). By the end of 1999, with few exceptions, the international JGOFS will have completed its 10-year fieldwork plan and will enter its global synthesis plan of the field results, which will be completed by the Year 2004.