Seawater carbonate chemistry and the organic ligands released by Emiliania huxleyi

DOI

The variability in the extracellular release of organic ligands by Emiliania huxleyi under four different pCO2 scenarios (225, 350, 600 and 900 μatm), was determined. Growth in the batch cultures was promoted by enriching them only with major nutrients and low iron concentrations. No chelating agents were added to control metal speciation. During the initial (IP), exponential (EP) and steady (SP) phases, extracellular release rates, normalized per cell and day, of dissolved organic carbon (DOCER), phenolic compounds (PhCER), dissolved combined carbohydrates (DCCHOER) and dissolved uronic acids (DUAER) in the exudates were determined.The growth rate decreased in the highest CO2 treatment during the IP (<48 h), but later increased when the exposure was longer (more than 6 days). DOCER did not increase significantly with high pCO2. Although no relationship was observed between DCCHOER and the CO2 conditions, DCCHO was a substantial fraction of the freshly released organic material, accounting for 18% to 37%, in EP, and 14% to 23%, in SP, of the DOC produced. Growth of E. huxleyi induced a strong response in the PhCER and DUAER. While in EP, PhCER were no detected, the DUAER remained almost constant for all CO2 treatments. Increases in the extracellular release of these organic ligands during SP were most pronounced under high pCO2 conditions. Our results imply that, during the final growth stage of E. huxleyi, elevated CO2 conditions will increase its excretion of acid polysaccharides and phenolic compounds, which may affect the biogeochemical behavior of metals in seawater.

In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2018-05-23.

Supplement to: Samperio-Ramos, Guillermo; Santana-Casiano, Juana Magdalena; González-Dávila, Melchor; Ferreira, Sonia; Coimbra, Manuel A (2017): Variability in the organic ligands released by Emiliania huxleyi under simulated ocean acidification conditions. AIMS Environmental Science, 4(6), 788-808

Identifier
DOI https://doi.org/10.1594/PANGAEA.891195
Related Identifier https://doi.org/10.3934/environsci.2017.6.788
Related Identifier https://cran.r-project.org/package=seacarb
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.891195
Provenance
Creator Samperio-Ramos, Guillermo; Santana-Casiano, Juana Magdalena ORCID logo; González-Dávila, Melchor ORCID logo; Ferreira, Sonia; Coimbra, Manuel A
Publisher PANGAEA
Contributor Yang, Yan
Publication Year 2017
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 388 data points
Discipline Earth System Research