Accessibility navigation


Polymorph selectivity of coccolith-associated polysaccharides from Gephyrocapsa oceanica on calcium carbonate formation in vitro

Walker, J. M., Marzec, B., Lee, R. B. Y., Vodrazkova, K., Day, S. J., Tang, C. C., Rickaby, R. E. M. and Nudelman, F. (2019) Polymorph selectivity of coccolith-associated polysaccharides from Gephyrocapsa oceanica on calcium carbonate formation in vitro. Advanced Functional Materials, 29 (1). 1807168. ISSN 1616-3028

[img]
Preview
Text - Accepted Version
· Please see our End User Agreement before downloading.

993kB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1002/adfm.201807168

Abstract/Summary

Coccolith-associated polysaccharides (CAPs) are thought to be a key part of the biomineralization process in coccolithophores, however their role is not fully understood. We have used two different systems that promote different polymorphs of calcium carbonate to show the effect of CAPs on nucleation and polymorph selection in vitro. Using a combination of time-resolved cryo-transmission electron microscopy (cryoTEM) and scanning electron microscopy (SEM), we examined the mechanisms of calcite nucleation and growth in the presence of the intracrystalline fraction containing CAPs extracted from coccoliths from Gephyrocapsa oceanica and Emiliania huxleyi, two closely related coccolithophore species. The CAPs extracted from G. oceanica were shown to promote calcite nucleation in vitro, even under conditions favouring the kinetic products of calcium carbonate, vaterite and aragonite. This was not the case with CAPs extracted from E. huxleyi, suggesting that the functional role of CAPs in vivo may be different between the two species. Additionally, high-resolution synchrotron powder X-ray diffraction (SXPD) revealed that the polysaccharide is located between grain boundaries of both calcite produced in the presence of the CAPs in vitro and biogenic calcite, rather than within the crystal lattice.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
ID Code:80131
Publisher:Wiley-Blackwell

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation