Cellular calcium pathways and isotope fractionation in Emiliania huxleyi

Gussone, Nikolaus, Langer, G., Thoms, S., Eisenhauer, Anton, Riebesell, Ulf and Wefer, G. (2006) Cellular calcium pathways and isotope fractionation in Emiliania huxleyi Geology, 34 (8). pp. 625-629. DOI 10.1130/G22733.1 .

[img] Text
Cellular calcium pathways.pdf - Reprinted Version
Restricted to Registered users only

Download (1761Kb) | Contact

Supplementary data:


The marine calcifying algae Emiliania huxleyi (coccolithophores) was grown in laboratory cultures under varying conditions with respect to the environmental parameters of temperature and carbonate ion concentration [CO32-] concentration. The Ca isotope composition of E. huxleyi's coccoliths reveals new insights into fractionation processes during biomineralization. The temperature-dependent Ca isotope fractionation resembles previous calibrations of inorganic and biogenic calcite and aragonite. Unlike inorganically precipitated calcite, the [CO32-] concentration of the medium has no significant effect on the Ca isotope composition of the coccoliths. These results indicate a decoupling of the chemical properties of the bulk medium and the calcifying vesicle. Cellular Ca pathways of E. huxleyi indicate that fractionation cannot occur at the crystal surface, as occurs during inorganic precipitation. The dominant processes leading to the observed Ca isotope fractionation pattern in E. huxleyi are most likely the dehydration of the Ca aquocomplex at the plasma membrane and the attachment of dissolved Ca to proteins of Ca channels. The independence of Ca isotope fractionation from [CO32-] and the small temperature dependence of E. huxleyi are also important for defining the isotopic signature of the oceanic Ca sink. Since coccolithophores contribute to about half the global CaCO3 production, a relatively uniform isotopic composition of the oceanic Ca sink is further supported.

Document Type: Article
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography
Refereed: Yes
DOI etc.: 10.1130/G22733.1
ISSN: 0091-7613
Date Deposited: 03 Dec 2008 16:51
Last Modified: 16 Jun 2017 11:38
URI: http://eprints.uni-kiel.de/id/eprint/1528

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...