@booklet {clark_coccolithophorids_2023,
	title = {Coccolithophorids precipitate carbonate in clumped isotope equilibrium with seawater},
	year = {2023},
	month = {nov},
	publisher = {EGUsphere},
	type = {preprint},
	abstract = {Numerous recent studies have tested the clumped isotope (Δ47) thermometer on a variety of biogenic carbonates such as foraminifera and bivalves and showed that all follow a common calibration. While the sample size requirements for a reliable Δ47 measurement have decreased over the years, the availability and preservation of many biogenic carbonates is still 10 limited and/or require substantial time to be extracted from sediments in sufficient amounts. We thus determined the Δ47temperature relationship for coccolith carbonate, which is abundant and often well-preserved in sediments. The carbon and oxygen isotopic compositions of coccolith calcite have limited use in palaeoenvironmental reconstructions due to physiological effects that cause variability in the carbon and oxygen isotopic values. However, the relatively limited data available suggest that clumped isotopes may not be influenced by these effects. We cultured three species of coccolithophores in well15 constrained carbonate system conditions with a CO2(aq) between 5 and 45 μM and temperatures between 6{\textdegree}C and 27{\textdegree}C.},
	keywords = {RCC1130, RCC1303, RCC3370},
	doi = {10.5194/egusphere-2023-2581},
	url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2581/},
	author = {Clark, Alexander J. and Torres-Romero, Ismael and Jaggi, Madalina and Bernasconi, Stefano M. and Stoll, Heather M.}
}
@article {BlancoAmeijeiras2020,
	title = {Influence of temperature and CO 2 on Plasma-membrane permeability to CO 2 and HCO 3 - in the marine haptophytes emiliania huxleyi and calcidiscus leptoporus (prymnesiophyceae)},
	journal = {Journal of Phycology},
	year = {2020},
	note = {tex.mendeley-tags: RCC1130,RCC1258},
	month = {jun},
	pages = {jpy.13017},
	abstract = {Membrane permeabilities to CO2 and HCO3- constrain the function of CO2 concentrating mechanisms that algae use to supply inorganic carbon for photosynthesis. In diatoms and green algae, plasma membranes are moderately to highly permeable to CO2 but effectively impermeable to HCO3-. Here, CO2 and HCO3- membrane permeabilities were measured using an 18O-exchange technique on two species of haptophyte algae, Emiliania huxleyi and Calcidiscus leptoporus, which showed that the plasma membranes of these species are also highly permeable to CO2 (0.006{\textendash}0.02 cm ? s-1) but minimally permeable to HCO3-. Increased temperature and CO2 generally increased CO2 membrane permeabilities in both species, possibly due to changes in lipid composition or CO2 channel proteins. Changes in CO2 membrane permeabilities showed no association with the density of calcium carbonate coccoliths surrounding the cell, which could potentially impede passage of compounds. Haptophyte plasma-membrane permeabilities to CO2 were somewhat lower than those of diatoms but generally higher than membrane permeabilities of green algae. One caveat of these measurements is that the model used to interpret 18O-exchange data assumes that carbonic anhydrase, which catalyzes 18O-exchange, is homogeneously distributed in the cell. The implications of this assumption were tested using a two-compartment model with an inhomogeneous distribution of carbonic anhydrase to simulate 18O-exchange data and then inferring plasma-membrane CO2 permeabilities from the simulated data. This analysis showed that the inferred plasma-membrane CO2 permeabilities are minimal estimates but should be quite accurate under most conditions.},
	keywords = {carbon concentrating mechanism, CO2, haptophyte, membrane, PERMEABILITY, RCC1130, rcc1258},
	issn = {0022-3646},
	doi = {10.1111/jpy.13017},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13017},
	author = {Blanco-Ameijeiras, Sonia and Stoll, Heather M. and Zhang, Hongrui and Hopkinson, Brian M.},
	editor = {Raven, J.}
}
