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Amino acid concentration and isotopic composition in sedimentary 13C-labeling incubation of sediment core HE483/25-2

Amino acids derivatization and analysis: Sediment slurries were centrifuged to separate the sediments from the medium and the sediments were freeze-dried and homogenized. 50 mg of samples spiked with the internal reference standard norleucine were decalcified and acid hydrolyzed (6M, 110℃) for 15 h. The hydrolysate was centrifuged to remove the sediments and subsequently defatted with hexane/ DCM mixture (V/V, 2:1) three times. The purification and derivatization of amino acids were performed by following the protocols described by Takano et al.53 and Chikaraishi et al.54, respectively. In brief, the hydrolysates were evaporated under N2 gas to dryness and purified using Dowex 50WX8 200 400 mesh cation exchange resin to eliminate the matrix effects. The purified amino acids were then isopropylated with a mixture of isopropanol and acetyl chloride (4/1, v/v) at 100 ℃ for 2 h. The solution was then evaporated to dryness and followed 3 times with DCM addition and evaporation to remove any remaining reagent. The AA isopropyl esters were then acylated using a mixture of pivaloyl chloride and DCM (1/1, v/v) at 100 ℃ for 2 h to obtain pivaloyl-isopropyl ester (Pv/AA/iPr). The Pv/AA/iPr solution was then evaporated to dryness and followed 3 times DCM addition and evaporation to remove any remaining reagent. Liquid-liquid extraction was performed by using MiliQ water and a hexane/DCM mixture (2/1, v/v). The Pv/AA/iPr were stored frozen (-20℃) and dissolved in ethyl acetate before analysis.

DIC concentration and isotopic composition in sedimentay 13C-labeling incubation of sediment core HE483/25-2

DIC measurement: an aliquot of the slurry was filtered with a 0.2-µm filter to remove cells and other particles. After filtration, 1 mL of samples were acidified with 100 μL 45% phosphoric acid overnight in an Exetainer® vial pre-purged with CO2-free air before analysis. All samples were measured with a Delta Ray Isotope Ratio Infrared Spectrometer (IRIS) with URI Connect and autosampler (Thermo Fisher Scientific, Germany) with an analytical error of ±1‰. All isotopic values are reported in the delta notation as δ13C relative to the Vienna PeeDee Belemnite (VPDB) standard. Deviations of triplicate isotopic measurement of sample DIC were between ± 1‰ and ± 1,000‰ (for DIC with label uptake of >10,000‰). DIC concentration was calculated from the released amount of CO2 by calibration with sodium hydrogen carbonate solution.

CO2 isotope in sedimentay 13C-labeling incubation of sediment core HE483/25-2

Incubation time was controlled based on the development of δ13C values of CO2 in the headspace. δ13C of CO2 was measured by Thermo Finnigan Trace GC coupled to a Thermo Finnigan Delta plus XP isotope ratio mass spectrometer (IRMS). Deviations of triplicate isotopic measurement of δ13C of CO2 were between ± 1‰ and ± 1,000‰ (for CO2 with label uptake of >10,000‰). Slurries were harvested at five time points for detailed analyses.

Amino acids and hexosamines in suspended matter samples collected in different oceanic areas between 1999 and 2017 from shelf seas to the deep ocean

This large set of suspended matter (SPM) samples was collected in different oceanic areas between 1999 and 2017 from shelf seas to the deep ocean. The samples were compiled from previous studies and used for statistical analyses in order to better understand particle dynamics and organic matter cycling in the ocean and to test and refine amino acid (AA) and hexosamine (HA) based biogeochemical indicators. Samples were analysed for total nitrogen (N) and total carbon (C) using a Carlo Erba nitrogen analyser 1500. Total organic carbon (TOC) was measured with the same instrument after treatment of weighed samples with 1N HCl to remove carbonate. Stable nitrogen isotopes of total particulate nitrogen (δ15N-TPN) were analysed with the mass spectrometer Thermo Finnigan MAT 252. AA and HA contents and their individual monomers were analysed by liquid chromatography using a Biochrom 30 amino acid analyzer. Contents of AA and HA are presented in nmol/g and µg/g. AAC, AAN, HAC, HAN are presented in µg/g and as percentages of TOC (AAC/C, HAC/C) or TN (AAN/N, HAN/N). AA and HA monomers are presented in Mol% and comprise aspartic acid (ASP), glutamic acid (Glu), threonine (Thr), serine (Ser), glycine (Gly), alanine (Ala), valine (Val), methionine (Met), isoleucine (Ile), leucine (Leu), tyrosine (Tyr), phenylalanine (Phe), β-Alanine (β-Ala), γ-aminobutyric acid (γ-Aba), histidine (His), ornithine (Orn), lysine (Lys) and arginine (Arg), glucosamine (Gluam) and galactosamine (Galam). Cysteic acid (CYA), taurine (TAU), methionine sulfoximine (MSO) and tryptophane (TRP) were determined only in the more recent samples. Data gaps indicate that measurements were not carried out or that they were not stored in the older data sets. The RI was calculated according to Jennerjahn and Ittekkot (1997; https://archimer.ifremer.fr/doc/00093/20403/) and the DI after Dauwe et al. (1999; doi:10.4319/lo.1999.44.7.1809). Definitions of biogeochemical indicators SDI, RTI, ox/anox and a detailed description of the methods can be found in Gaye et al. (2022).

Amino acids and hexosamine in sediment trap samples from different oceanic areas collected between 1993 and 2017 from shelf seas to the deep ocean

This large set of sediment trap samples was collected in different oceanic areas between 1993 and 2017 from shelf seas to the deep ocean. The samples were compiled from previous studies and used for statistical analyses in order to better understand particle dynamics and organic matter cycling in the ocean and to test and refine amino acid (AA) and hexosamine (HA) based biogeochemical indicators. Samples were analysed for total nitrogen (N) using a Carlo Erba nitrogen analyser 1500. Total organic carbon (TOC) was measured with the same instrument after treatment of weighed samples with 1N HCl to remove carbonate. Stable nitrogen isotopes of total particulate nitrogen (δ15N-TPN) were analysed with the mass spectrometer ThermoFisher Scientific MAT 252. AA and HA contents and their individual monomers were analysed by liquid chromatography using a Biochrom 30 amino acid analyzer. Total fluxes, TOC and AA fluxes were calculated in mg m-2 d-1. Contents of AA and HA are presented in µmol/g and µg/g. AAC, AAN, HAC, HAN are presented in µg/g and as percentages of TOC (AA-C/C, HA-C/C) or TN (AA-N/N, HA-N/N). AA and HA monomers are presented in Mol% and comprise aspartic acid (ASP), glutamic acid (Glu), threonine (Thr), serine (Ser), glycine (Gly), alanine (Ala), valine (Val), methionine (Met), isoleucine (Ile), leucine (Leu), tyrosine (Tyr), phenylalanine (Phe), β-Alanine (β-Ala), γ-aminobutyric acid (γ-Aba), histidine (His), ornithine (Orn), lysine (Lys) and arginine (Arg), glucosamine (GlcN) and galactosamine (GalN), cysteic acid (CYA), taurine (TAU), methionine sulfoximine (MSO) and tryptophane (TRP) were determined only in the more recent samples. Data gaps indicate that measurements were not carried out or that they were not stored in the older data sets. The RI was calculated according to Jennerjahn and Ittekkot (1997; https://archimer.ifremer.fr/doc/00093/20403/) and the DI after Dauwe et al. (1999; doi:10.4319/lo.1999.44.7.1809). Definitions of biogeochemical indicators SDI, RTI, ox/anox and a detailed description of the methods can be found in Gaye et al. (2022; doi:org/10.5194/bg-19-807-2022).

Hydrology at CTD stations during Alkor cruises AL510 and Al516

During two crusies in June (AL510) and September (AL516) 2018, a data set (N=76) from the sea surface microlayer (SML) was compiled in Eckernförde Bay, Germany. SML samples were collected with the glass plate technique. Reference samples from the underlying water (ULW) at an approx. depth of 20cm were collected with the help of a bottle. Total and dissolved hydrolysable amino acids, combined carbohydrates and dissolved organic carbon were analyzed to describe surfactant dynamics (based on phase-sensitive AC voltammetry). Flow cytometry provided additional information on bacteria and phytoplankton community composition. This data set resolves dynamics on short temporal (diurnal sampling ) and local scales (within an area of 50km^2).

Bulk organic matter concentrations and microorganisms abundance at SML stations during Alkor cruises AL510 and AL516

During two crusies in June (AL510) and September (AL516) 2018, a data set (N=76) from the sea surface microlayer (SML) was compiled in Eckernförde Bay, Germany. SML samples were collected with the glass plate technique. Reference samples from the underlying water (ULW) at an approx. depth of 20cm were collected with the help of a bottle. Total and dissolved hydrolysable amino acids, combined carbohydrates and dissolved organic carbon were analyzed to describe surfactant dynamics (based on phase-sensitive AC voltammetry). Flow cytometry provided additional information on bacteria and phytoplankton community composition. This data set resolves dynamics on short temporal (diurnal sampling ) and local scales (within an area of 50km^2).

Meteorology at SML stations during Alkor cruises AL510 and AL516

During two crusies in June (AL510) and September (AL516) 2018, a data set (N=76) from the sea surface microlayer (SML) was compiled in Eckernförde Bay, Germany. SML samples were collected with the glass plate technique. Reference samples from the underlying water (ULW) at an approx. depth of 20cm were collected with the help of a bottle. Total and dissolved hydrolysable amino acids, combined carbohydrates and dissolved organic carbon were analyzed to describe surfactant dynamics (based on phase-sensitive AC voltammetry). Flow cytometry provided additional information on bacteria and phytoplankton community composition. This data set resolves dynamics on short temporal (diurnal sampling ) and local scales (within an area of 50km^2).

Amino acids at SML stations during Alkor cruises AL510 and AL516

During two crusies in June (AL510) and September (AL516) 2018, a data set (N=76) from the sea surface microlayer (SML) was compiled in Eckernförde Bay, Germany. SML samples were collected with the glass plate technique. Reference samples from the underlying water (ULW) at an approx. depth of 20cm were collected with the help of a bottle. Total and dissolved hydrolysable amino acids, combined carbohydrates and dissolved organic carbon were analyzed to describe surfactant dynamics (based on phase-sensitive AC voltammetry). Flow cytometry provided additional information on bacteria and phytoplankton community composition. This data set resolves dynamics on short temporal (diurnal sampling ) and local scales (within an area of 50km^2).

Carbohydrates at SML stations during Alkor cruises AL510 and AL516

During two crusies in June (AL510) and September (AL516) 2018, a data set (N=76) from the sea surface microlayer (SML) was compiled in Eckernförde Bay, Germany. SML samples were collected with the glass plate technique. Reference samples from the underlying water (ULW) at an approx. depth of 20cm were collected with the help of a bottle. Total and dissolved hydrolysable amino acids, combined carbohydrates and dissolved organic carbon were analyzed to describe surfactant dynamics (based on phase-sensitive AC voltammetry). Flow cytometry provided additional information on bacteria and phytoplankton community composition. This data set resolves dynamics on short temporal (diurnal sampling ) and local scales (within an area of 50km^2).

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