ALBERT

Description: This data comprises two files. One file called chamber data contains information such as surface area and weight of Fucus vesiculosus and Zostera marina specimen that were used in a 5 h in situ incubation. In a separate sheet, it contains the results of water sample analyses before and after the incubation such as dissolved organic carbon concentrations. The second file contains results from antibody staining and high performance anion exchange chromatography intended to detect and quantify glycans. The field experiments and water sample analyses were conducted in August 2020 at Tvärminne Zoological Station, Hanko Finland. The glycan analyses were performed in 2020 and 2021 at the Max-Planck-Institute for marine microbiology in Bremen, Germany. This data was collected to investigate dissolved organic molecules that are released by seagrass and brown algae within the framework of an Assemble Plus Transnational Access project called Contributions of organic carbon from vegetated coastal ecosystems​.

Description: This data was collected to investigate dissolved organic molecules that are released by seagrass and brown algae within the framework of an Assemble Plus Transnational Access project called Contributions of organic carbon from vegetated coastal ecosystems. The field experiments and water sample analyses were conducted in August 2020 at Tvärminne Zoological Station, Hanko Finland. The binary file glycan_data_ELISA contains results from antibody staining of seawater samples from algae incubations. Two fucoidan-targeting monoclonal antibodies were used, namely BAM1 and BAM2. Signal intensity indicating recognition of the substrate target in a sample by the antibody is given as relative intensity normalized to 1. The binary file glycan_data_HPAEC-PAD contains unprocessed results from high performance anion exchange chromatography which was used to quantify monosaccharides. Glycans in the samples were degraded to monosaccharides unspecifically using acid hydrolysis, or in a targeted manner using an enzyme cocktail specific to fucoidan. The binary file glycan_data_Fig2c contains data on fucoidan extraction from seawater using anion exchange chromatography. During the chromatography, two consecutive elution steps first with 2 M ammonium bicarbonate followed by 5 M sodium chloride were performed. The two eluted fractions were analyzed separately and results for monosaccharide content are given in this table. These glycan analyses were performed in 2020 and 2021 at the Max-Planck-Institute for marine microbiology in Bremen, Germany.

Description: For seagrass incubations, August 5, 2020, seagrass shoots were enclosed in transparent gas impermeable plastic vacuum bags (Packing24, PA/PE 20/70, 90my) with approx. 6 L of the surrounding water. The bags were sealed onto the PVC tubes of ~12 cm diameter installed in the sediment one day earlier. Half of the incubations were covered with black bags to simulate dark conditions. Immediately prior to starting the incubations, water was sampled from the ambient water to determine initial conditions. At the end of the incubation, all seagrass tissue, above- and below-ground, was collected. Water from within chambers was collected for analyses. In the laboratory, the length and width of each seagrass shoot was measured. Epiphytes and epifauna were scraped off seagrass shoots using a razor blade, and collected separately from the seagrass biomass. All biomass was frozen and subsequently freeze-dried for 24 hours, and weighed to determine dry weight.

Description: Water column samples from seagrass incubations were collected into acid washed single use, sterile, 60 mL syringes (Thermo Fisher Scientific, USA) via water column ports on the PVC tubes. Water column samples from algae incubations were collected into acid washed 60 mL syringes after opening incubation bags on board. Water column samples were filtered immediately through a precombusted 45 mm diameter glass microfiber GF/F filter (Whatman, UK). For each sample, 30 mL were pushed through the filter for rinsing before starting collection. To determine the concentration of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN), 15 mL sample were filtered into a precombusted 24 mL glass vial containing 60 µL 25% hydrochloric acid and the vial sealed with an acid washed teflon-lined cap. Another 10 mL of sample were filtered into a precombusted 12 mL glass vial and the vial sealed with an acid washed teflon-lined cap for colored dissolved organic matter (CDOM) and fluorescent dissolved organic matter (FDOM) analysis. Subsamples for DOC were frozen at -20°C and samples for CDOM/FDOM were stored at 4°C until analysis within two weeks. Optical FireSting O2 sensors (Pyroscience GmbH, Germany) were used to determine oxygen concentrations in water samples. Calibration of the sensors was achieved using MilliQ water. Oxygen concentrations were measured in 600 mL subsamples from water column within two hours of sample collection. For algae incubations, oxygen concentrations could also be determined in water from incubations without prior filtration. For DOC and TDN concentrations, the samples were analyzed using a Shimadzu TOC-VCPH-analyzer and an autoanalyzer (Aquakem 250). CDOM absorption was measured using a Shimadzu 2401PC spectrophotometer with 5 cm quartz cuvette over the spectral range from 200 to 800 nm with 1 nm resolution. Ultrapure water was used as the blank for all samples. Excitation-emission matrices (EEMs) of FDOM were measured with a Varian Cary Eclipse fluorometer (Agilent). Processing of the EEMs was done using the eemR package for R software. A blank sample of ultrapure water was subtracted from the EEMs, and the Rayleigh and Raman scattering bands were removed from the spectra after calibration. EEMs were calibrated by normalizing to the area under the Raman water scatter peak (excitation wavelength of 350 nm) of an ultrapure water sample run on the same session as the samples, and were corrected for inner filter effects with absorbance spectra.

Description: For the algae incubations on August 18, 2020, transparent gas impermeable plastic vacuum bags (Packing24, PA/PE 20/70, 90my) with a single F. vesiculosus thallus, were closed with rubber bands around PVC end cap fitting of 12 cm diameter and attached to a bottom-anchored line at ~1 m depth. Thalli of ~50 cm length were detached close to the base by cutting the few millimeters thick, old stipe. Half of the incubations were covered with black bags to simulate dark conditions. Immediately prior to starting the incubations, water was sampled from the ambient water to determine initial conditions. At the end of the incubation, all algal tissue was collected. Water from within chambers was collected for analyses and the total volume measured. In the laboratory, the algal thallus was spread out across a cutting mat with a grid for surface area estimation. Epiphytes and epifauna were scraped off thalli using a razor blade, and collected separately from the algal biomass. All biomass was frozen and subsequently freeze-dried for 24 hours, and weighed to determine dry weight.

Description: Algae synthesise structurally complex glycans to build a protective barrier, the extracellular matrix. One function of matrix glycans is to slow down microorganisms that try to enzymatically enter living algae and degrade and convert their organic carbon back to carbon dioxide. We propose that matrix glycans lock up carbon in the ocean by controlling degradation of organic carbon by bacteria and other microbes not only while algae are alive, but also after death. Data revised in this review shows accumulation of algal glycans in the ocean underscoring the challenge bacteria and other microbes face to breach the glycan barrier with carbohydrate active enzymes. Briefly we also update on methods required to certify the uncertain magnitude and unknown molecular causes of glycan-controlled carbon sequestration in a changing ocean.