ALBERT

Description: 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.

Description: 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).

Description: Kelps, perennial brown seaweeds of the order Laminariales, are foundational species in Arctic coastal ecosystems. Presently, their ability to persist under polar night conditions might be significantly affected by increasing winter temperatures. We assessed physiological parameters (photosynthesis, pigment content, respiration, carbohydrate storage) in two species of Arctic kelp, the boreal-temperate Saccharina latissima and the Arctic-endemic Laminaria solidungula, during the polar night 2016/17. Algae were sampled from Kongsfjorden, Svalbard, 78° 55' N, shortly before the onset of the dark period in October, and at the end of the polar night in early February. Analyses were conducted for different tissue sections along the phylloid (Meristem, Centre Region, Distal Region). Data suggest that kelp maintain their photosynthetic competence throughout the entire winter period, as indicated by PE-curve-parameters, and photosynthetic pigment contents. Overall laminarin content was reduced by 96 % in S. latissima, and by 90 % in L. solidungula during winter indicating that this storage glucan fuelled metabolic function during the polar night. Marked differences in laminarin content between the phylloid regions and across species indicated specific adaptive mechanisms between boreal-temperate and Arctic-endemic kelp. We suggest that laminarin turnover represents a sensitive parameter to assess kelp physiology under a changing temperature regime.

Description: 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.