@booklet {de_vries_critical_2023,
	title = {A critical trade-off between nitrogen quota and growth allows Coccolithus braarudii life cycle phases{\textquoteright} to exploit varying environment},
	year = {2023},
	publisher = {Biodiversity and Ecosystem Function: Marine},
	type = {preprint},
	abstract = {Coccolithophores have a distinct haplo-diplontic life cycle, which allows them to grow and divide in two different life cycle phases (haploid and diploid). These life cycle phases vary significantly in inorganic carbon content and morphology, and inhabit distinct niches, with haploids generally preferring low-nutrient and high-temperature and -light environments. This niche contrast indicates different physiology of the life cycle phases, which is considered here in the context of a trait trade-off 5 framework, in which a particular set of traits comes with both costs and benefits. However, coccolithophore{\textquoteright}s phase trade-offs are not fully identified, limiting our understanding of the functionality of the coccolithophore life cycle. Here, we investigate the response of the two life cycle phases of the coccolithophore Coccolithus braarudii to key environmental drivers: light, temperature and nutrients, using laboratory experiments. With this data, we identify the main trade-offs of each life cycle phase and use models to test the role of such trade-offs under different environmental conditions.},
	keywords = {RCC1200, RCC1203, RCC3777, RCC3779, RCC6535},
	doi = {10.5194/egusphere-2023-880},
	url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-880/},
	author = {De Vries, Joost and Monteiro, Fanny and Langer, Gerald and Brownlee, Colin and Wheeler, Glen}
}
@article {ben-joseph_crystallization_2023,
	title = {Crystallization of Coccolith Calcite at Different Life-Cycle Phases Exhibits Distinct Degrees of Cellular Confinement},
	journal = {Small Structures},
	volume = {n/a},
	number = {n/a},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/sstr.202200353},
	pages = {2200353},
	abstract = {Coccolithophores are a group of unicellular marine algae that shape global geochemical cycles via the production of calcium carbonate crystals. Interestingly, different life-cycle phases of the same coccolithophore species produce very different calcitic scales, called coccoliths. In the widely studied diploid phase, the crystals have anisotropic and complex morphologies, while haploid cells produce coccoliths consisting solely of calcite crystals with simple rhombohedral morphology. Understanding how these two life-cycle phases control crystallization is a highly sought-after goal, yet, haploid phase crystallization has rarely been studied, and the process by which they form is unknown. Herein, advanced electron microscopy is employed to elucidate the cellular architecture of the calcification process in haploid cells. The results show that in contrast to diploid-phase calcification, the coccolith-forming vesicle of haploid-phase cells is voluminous. In this solution-like environment, the crystals nucleate and grow asynchronously in a process that resembles calcite growth in bulk solution, leading to the simple morphologies of the crystals. The two distinct mineralization regimes of coccolithophore life-cycle phases suggest that cellular architecture, and specifically confinement of the crystallization process, is a pivotal determinant of biomineral morphology and assembly.},
	keywords = {biomineralization, calcites, Coccoliths, crystal growths, haploid{\textendash}diploid life cycles, RCC1181, RCC3777},
	issn = {2688-4062},
	doi = {10.1002/sstr.202200353},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202200353},
	author = {Ben-Joseph, Oz and de Haan, Diede and Rechav, Katya and Shimoni, Eyal and Levin-Zaidman, Smadar and Langer, Gerald and Probert, Ian and Wheeler, Glen L. and Gal, Assaf}
}
@article {klintzsch_stable_2023,
	title = {Stable Carbon Isotope Signature of Methane Released from Phytoplankton},
	journal = {Geophysical Research Letters},
	year = {2023},
	month = {feb},
	abstract = {Aquatic ecosystems play an important role in global methane cycling and many field studies have reported methane supersaturation in the oxic surface mixed layer (SML) of the ocean and in the epilimnion of lakes. The origin of methane formed under oxic condition is hotly debated and several pathways have recently been offered to explain the {\textquoteleft}methane paradox{\textquoteright}. In this context, stable isotope measurements have been applied to constrain methane sources in supersaturated oxygenated waters. Here we present stable carbon isotope signatures for six widespread marine phytoplankton species, three haptophyte algae and three cyanobacteria, incubated under laboratory conditions. The observed isotopic patterns implicate that methane formed by phytoplankton might be clearly distinguished from methane produced by methanogenic archaea. Comparing results from phytoplankton experiments with isotopic data from field measurements, suggests that algal and cyanobacterial populations may contribute substantially to methane formation observed in the SML of oceans and lakes.},
	keywords = {RCC1216, ⛔ No DOI found},
	doi = {10.22541/essoar.167689993.32180072/v1},
	url = {https://essopenarchive.org/users/587513/articles/625160-stable-carbon-isotope-signature-of-methane-released-from-phytoplankton?commit=633a121ee07c48e6c59ffeca06fd5d5ebe1df4d4},
	author = {Klintzsch, Thomas and Geisinger, Hannah and Wieland, Anna and Langer, Gerald and Nehrke, Gernot and Bizic, Mina and Greule, Markus and Lenhart, Katharina and Borsch, Christian and Schroll, Moritz and Keppler, Frank}
}
@article {johnson_nutritional_2022,
	title = {Nutritional response of a coccolithophore to changing pH and temperature},
	journal = {Limnology and Oceanography},
	volume = {n/a},
	number = {n/a},
	year = {2022},
	note = {_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.12204},
	abstract = {Coccolithophores are a calcifying unicellular phytoplankton group that are at the base of the marine food web, and their lipid content provides a source of energy to consumers. Coccolithophores are vulnerable to ocean acidification and warming, therefore it is critical to establish the effects of climate change on these significant marine primary producers, and determine potential consequences that these changes can have on their consumers. Here, we quantified the impact of changes in pH and temperature on the nutritional condition (lipid content, particulate organic carbon/nitrogen), growth rate, and morphology of the most abundant living coccolithophore species, Emiliania huxleyi. We used a regression type approach with nine pH levels (ranging from 7.66 to 8.44) and two temperatures (15{\textdegree}C and 20{\textdegree}C). Lipid production was greater under reduced pH, and growth rates were distinctly lower at 15{\textdegree}C than at 20{\textdegree}C. The production potential of lipids, which estimates the availability of lipids to consumers, increased under 20{\textdegree}C, but decreased under low pH. The results indicate that, while consumers will benefit energetically under ocean warming, this benefit will be mitigated by ocean acidification. The carbon to nitrogen ratio was higher at 20{\textdegree}C and low pH, indicating that the nutritional quality of coccolithophores for consumers will decline under climate change. The impact of low pH on the structural integrity of the coccosphere may also mean that coccolithophores are easier to digest for consumers. Many responses suggest cellular stress, indicating that increases in temperature and reductions in pH may have a negative impact on the ecophysiology of coccolithophores.},
	keywords = {RCC1832},
	issn = {1939-5590},
	doi = {10.1002/lno.12204},
	url = {http://onlinelibrary.wiley.com/doi/abs/10.1002/lno.12204},
	author = {Johnson, Roberta and Langer, Gerald and Rossi, Sergio and Probert, Ian and Mammone, Marta and Ziveri, Patrizia}
}
@article {langer_role_2021,
	title = {Role of silicon in the development of complex crystal shapes in coccolithophores},
	journal = {New Phytologist},
	volume = {231},
	number = {5},
	year = {2021},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.17230},
	pages = {1845{\textendash}1857},
	abstract = {The development of calcification by the coccolithophores had a profound impact on ocean carbon cycling, but the evolutionary steps leading to the formation of these complex biomineralized structures are not clear. Heterococcoliths consisting of intricately shaped calcite crystals are formed intracellularly by the diploid life cycle phase. Holococcoliths consisting of simple rhombic crystals can be produced by the haploid life cycle stage but are thought to be formed extracellularly, representing an independent evolutionary origin of calcification. We use advanced microscopy techniques to determine the nature of coccolith formation and complex crystal formation in coccolithophore life cycle stages. We find that holococcoliths are formed in intracellular compartments in a similar manner to heterococcoliths. However, we show that silicon is not required for holococcolith formation and that the requirement for silicon in certain coccolithophore species relates specifically to the process of crystal morphogenesis in heterococcoliths. We therefore propose an evolutionary scheme in which the lower complexity holococcoliths represent an ancestral form of calcification in coccolithophores. The subsequent recruitment of a silicon-dependent mechanism for crystal morphogenesis in the diploid life cycle stage led to the emergence of the intricately shaped heterococcoliths, enabling the formation of the elaborate coccospheres that underpin the ecological success of coccolithophores.},
	keywords = {biomineralization, Calcification, coccolith, coccolithophore, evolution, rcc, RCC1178, RCC1181, RCC1456, RCC1460, RCC1461, RCC1477, RCC1800, RCC1801, RCC3777, RCC6506, silicon},
	issn = {1469-8137},
	doi = {10.1111/nph.17230},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.17230},
	author = {Langer, Gerald and Taylor, Alison R. and Walker, Charlotte E. and Meyer, Erin M. and Ben Joseph, Oz and Gal, Assaf and Harper, Glenn M. and Probert, Ian and Brownlee, Colin and Wheeler, Glen L.}
}
@article {Langer2020,
	title = {Li partitioning into coccoliths of Emiliania huxleyi : evaluating the general role of {\textquotedblleft}vital effects{\textquotedblright} in explaining element partitioning in biogenic carbonates},
	journal = {Geochemistry, Geophysics, Geosystems},
	year = {2020},
	note = {ISBN: 0000000272 tex.mendeley-tags: RCC3652},
	month = {jun},
	pages = {0{\textendash}2},
	abstract = {Abstract Emiliania huxleyi cells were grown in artificial seawater of different Li and Ca concentrations and coccolith Li/Ca ratios determined. Coccolith Li/Ca ratios were positively correlated to seawater Li/Ca ratios only if the seawater Li concentration was changed, not if the seawater Ca concentration was changed. This Li partitioning pattern of E. huxleyi was previously also observed in the benthic foraminifer Amphistegina lessonii and inorganically precipitated calcite. We argue that Li partitioning in both E. huxleyi and A. lessonii is dominated by a coupled transmembrane transport of Li and Ca from seawater to the site of calcification. We present a refined version of a recently proposed transmembrane transport model for Li and Ca. The model assumes that Li and Ca enter the cell via Ca channels, the Li flux being dependent on the Ca flux. While the original model features a linear function to describe the experimental data, our refined version uses a power function, changing the stoichiometry of Li and Ca. The version presented here accurately predicts the observed dependence of DLi on seawater Li/Ca ratios. Our data demonstrate that minor element partitioning in calcifying organisms is partly mediated by biological processes even if the partitioning behaviour of the calcifying organism is indistinguishable from that of inorganically precipitated calcium carbonate.},
	keywords = {RCC3652},
	issn = {1525-2027},
	doi = {10.1029/2020GC009129},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GC009129},
	author = {Langer, Gerald and Sadekov, Aleksey and Greaves, Mervyn and Nehrke, Gernot and Probert, Ian and Misra, Sambuddha and Thoms, Silke}
}
@article {Meyer2020,
	title = {Sr in coccoliths of Scyphosphaera apsteinii: Partitioning behavior and role in coccolith morphogenesis},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {285},
	year = {2020},
	note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC1456},
	month = {sep},
	pages = {41{\textendash}54},
	abstract = {Coccolithophores are important contributors to global calcium carbonate through their species-specific production of calcite coccoliths. Nannofossil coccolith calcite remains an important tool for paleoreconstructions through geochemical analysis of isotopic and trace element incorporation including Sr, which is a potential indicator of past surface ocean temperature and productivity. Scyphosphaera apsteinii (Zygodiscales) exhibits an unusually high Sr/Ca ratio and correspondingly high partitioning coefficient (DSr = 2.5) in their two morphologically distinct types of coccoliths: flat muroliths and barrel-like lopadoliths. Whether or not this reflects mechanistic differences in calcification compared to other coccolithophores is unknown. We therefore examined the possible role of Sr in S. apsteinii calcification by growing cells in deplete (0.33 mmol/mol Sr/Ca), ambient (9 mmol/mol Sr/Ca), and higher than ambient Sr conditions (36 and 72 mmol/mol Sr/Ca). The effects on growth, quantum efficiency of photosystem II (Fv/Fm), coccolith morphology, and calcite DSr were evaluated. No effect on S. apsteinii growth rate or Fv/Fm was observed when cells were grown in Sr/Ca between 0.33{\textendash}36 mmol/mol. However, at 72 mmol/mol Sr/Ca growth rate was significantly reduced, although Fv/Fm was unaffected. Reducing the Sr/Ca from ambient (9 mmol/mol) did not significantly alter the frequency of malformed and aberrant muroliths and lopadoliths, but at higher than ambient Sr/Ca conditions coccolith morphology was significantly disrupted. This implies that Sr is not a critical determining factor in normal coccolith calcite morphology in this dimorphic species. Using energy dispersive spectroscopy (EDS) we observed an increase in [Sr] and decrease in DSr of coccoliths as the Sr/Ca of the growth medium increased. Interestingly, muroliths had significantly lower Sr/Ca than lopadoliths at ambient and elevated [Sr], and lopadolith tips had lower Sr than bases in ambient conditions. In summary, the Sr fractionation behavior of S. apsteinii is distinct from other coccolithophores because of an unusually high DSr and inter- and intra-coccolith variability in Sr/Ca. These observations could be explained by mechanistic differences in the selectivity of the Ca2+ transport pathway or in the Sr-and Ca-binding capacity of organic components, such as polysaccharides associated with coccolithogenesis.},
	keywords = {biomineralization, Calcification, coccolith, coccolithophore, Energy dispersive spectroscopy, Fractionation, RCC1456, Sr/Ca, Strontium, Trace element},
	issn = {00167037},
	doi = {10.1016/j.gca.2020.06.023},
	author = {Meyer, Erin M. and Langer, Gerald and Brownlee, Colin and Wheeler, Glen L. and Taylor, Alison R.}
}
@article {Klintzsch2019,
	title = {Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment},
	journal = {Biogeosciences},
	volume = {16},
	number = {20},
	year = {2019},
	note = {tex.mendeley-tags: RCC1216},
	month = {oct},
	pages = {4129{\textendash}4144},
	keywords = {RCC1216},
	issn = {1726-4189},
	doi = {10.5194/bg-16-4129-2019},
	url = {https://www.biogeosciences.net/16/4129/2019/},
	author = {Klintzsch, Thomas and Langer, Gerald and Nehrke, Gernot and Wieland, Anna and Lenhart, Katharina and Keppler, Frank}
}
@article {Walker2018,
	title = {The requirement for calcification differs between ecologically important coccolithophore species},
	journal = {New Phytologist},
	volume = {in press},
	year = {2018},
	note = {tex.mendeley-tags: RCC1731},
	month = {jun},
	keywords = {Calcification, coccolithophore, Coccolithus braarudii, Emiliania huxleyi, phytoplankton, rcc1731},
	issn = {0028646X},
	doi = {10.1111/nph.15272},
	url = {http://doi.wiley.com/10.1111/nph.15272},
	author = {Walker, Charlotte E. and Taylor, Alison R. and Langer, Gerald and Durak, Gra{\.z}yna M. and Heath, Sarah and Probert, Ian and Tyrrell, Toby and Brownlee, Colin and Wheeler, Glen L.}
}
@article {Rosas-Navarro2018,
	title = {Temperature effects on sinking velocity of different Emiliania huxleyi strains},
	journal = {PLOS ONE},
	volume = {13},
	number = {3},
	year = {2018},
	note = {ISBN: 1111111111 tex.mendeley-tags: IAN01,RCC1252,RCC1710},
	pages = {e0194386},
	abstract = {The sinking properties of three strains of Emiliania huxleyi in response to temperature changes were examined. We used a recently proposed approach to calculate sinking velocities from coccosphere architecture, which has the advantage to be applicable not only to culture samples, but also to field samples including fossil material. Our data show that temperature in the sub-optimal range impacts sinking velocity of E. huxleyi. This response is widespread among strains isolated in different locations and moreover comparatively predictable, as indicated by the similar slopes of the linear regressions. Sinking velocity was positively correlated to temperature as well as individual cell PIC/POC over the sub-optimum to optimum temperature range in all strains. In the context of climate change our data point to an important influence of global warming on sinking velocities. It has recently been shown that seawater acidification has no effect on sinking velocity of a Mediterranean E. huxleyi strain, while nutrient limitation seems to have a small negative effect on sinking velocity. Given that warming, acidification, and lowered nutrient availability will occur simultaneously under climate change scenarios, the question is what the net effect of different influential factors will be. For example, will the effects of warming and nutrient limitation cancel? This question cannot be answered conclusively but analyses of field samples in addition to laboratory culture studies will improve predictions because in field samples multi-factor influences and even evolutionary changes are not excluded. As mentioned above, the approach of determining sinking rate followed here is applicable to field samples. Future studies could use it to analyse not only seasonal and geographic patterns but also changes in sinking velocity over geological time scales.},
	keywords = {IAN01, rcc1252, rcc1710},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0194386},
	url = {http://dx.plos.org/10.1371/journal.pone.0194386},
	author = {Rosas-Navarro, Anaid and Langer, Gerald and Ziveri, Patrizia},
	editor = {Johnson, Colin}
}
@article {Rosas-Navarro2016,
	title = {Temperature affects the morphology and calcification of Emiliania huxleyi strains},
	journal = {Biogeosciences},
	volume = {13},
	number = {10},
	year = {2016},
	note = {tex.mendeley-tags: 2016,rcc1252,rcc1710},
	month = {may},
	pages = {2913{\textendash}2926},
	abstract = {The global warming debate has sparked an unprecedented interest in temperature effects on coccolithophores. The calcification response to temperature changes reported in the literature, however, is ambiguous. The two main sources of this ambiguity are putatively differences in experimental setup and strain specificity. In this study we therefore compare three strains isolated in the North Pacific under identical experimental conditions. Three strains of Emiliania huxleyi type A were grown under non-limiting nutrient and light conditions, at 10, 15, 20 and 25 {\textdegree}C. All three strains displayed similar growth rate versus temperature relationships, with an optimum at 20{\textendash}25 {\textdegree}C. Elemental production (particulate inorganic carbon (PIC), particulate organic carbon (POC), total particulate nitrogen (TPN)), coccolith mass, coccolith size, and width of the tube element cycle were positively correlated with temperature over the sub-optimum to optimum temperature range. The correlation between PIC production and coccolith mass/size supports the notion that coccolith mass can be used as a proxy for PIC production in sediment samples. Increasing PIC production was significantly positively correlated with the percentage of incomplete coccoliths in one strain only. Generally, coccoliths were heavier when PIC production was higher. This shows that incompleteness of coccoliths is not due to time shortage at high PIC production. Sub-optimal growth temperatures lead to an increase in the percentage of malformed coccoliths in a strain-specific fashion. Since in total only six strains have been tested thus far, it is presently difficult to say whether sub-optimal temperature is an important factor causing malformations in the field. The most important parameter in biogeochemical terms, the PIC : POC ratio, shows a minimum at optimum growth temperature in all investigated strains. This clarifies the ambiguous picture featuring in the literature, i.e. discrepancies between PIC : POC{\textendash}temperature relationships reported in different studies using different strains and different experimental setups. In summary, global warming might cause a decline in coccolithophore{\textquoteright}s PIC contribution to the rain ratio, as well as improved fitness in some genotypes due to fewer coccolith malformations.},
	keywords = {2016, rcc1252, rcc1710},
	issn = {1726-4189},
	doi = {10.5194/bg-13-2913-2016},
	url = {http://www.biogeosciences.net/13/2913/2016/},
	author = {Rosas-Navarro, Anaid and Langer, Gerald and Ziveri, Patrizia}
}
@article {Langer2011a,
	title = {CO2 mediation of adverse effects of seawater acidification in Calcidiscus leptoporus},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {12},
	number = {5},
	year = {2011},
	note = {ISBN: 1525-2027 tex.mendeley-tags: 2011,RCC1135,rcc},
	pages = {1{\textendash}8},
	abstract = {The coccolithophore Calcidiscus leptoporus (strain RCC1135) was grown in dilute batch culture at CO2 levels ranging from \~200 to \~1600 matm. Increasing CO2 concentration led to an increased percentage of malformed coccoliths and eventually (at \~1500 matm CO2) to aggregation of cells. Carbonate chemistry of natural seawater was manipulated in three ways: first, addition of acid; second, addition of a HCO3 -/CO3 2- solution; and third, addition of both acid and HCO3 -/CO32- solution. The data set allowed the disentangling of putative effects of the different parameters of the carbonate system. It is concluded that CO2 is the parameter of the carbonate system which causes both aberrant coccolithogenesis and aggregation of cells.},
	keywords = {2011, Calcification, coccolithophores, morphology, ocean acidification., rcc, RCC1135},
	issn = {1525-2027},
	doi = {10.1029/2010GC003393},
	url = {http://www.agu.org/pubs/crossref/2011/2010GC003393.shtml},
	author = {Langer, Gerald and Bode, Maya}
}
