Calcifying Coccolithophore: An Evolutionary Advantage Against Extracellular Oxidative Damage

Abstract

The evolutionary advantages afforded by phytoplankton calcification remain enigmatic. In this work, fluoroelectrochemical experiments reveal that the presence of a CaCO3 shell of a naturally calcifying coccolithophore, Coccolithus braarudii, offers protection against extracellular oxidants as measured by the time required for the switch‐off in their chlorophyll signal, compared to the deshelled equivalents, suggesting the shift toward calcification offers some advantages for survival in the surface of radical‐rich seawater.

Controlling crystallisation and dissolution of biogenic CaCO3via dissolved magnesium cations

“…The construction of an elaborate calcite shell, despite an estimated cost of one third of its photosynthetic budget, 13 has been suggested to provide the single-cell organism with an edge to survival including protection against virus infection, zooplankton grazing, and protection from photo- and/or oxidative damage. 13,14 Furthermore, the dense CaCO 3 acts as a ballast, sinking the inorganic and organic carbon biomineralized in the sun-lit surface to the deep. Ancient coccoliths found in sediment traps date back as far as ca.…”

Vaterite Dissolution: Mechanism and Kinetics

“…Notably, studying the involvement of calcium carbonate in the carbon cycle can offer valuable insights into atmospheric CO 2 levels . In a biological context, certain marine phytoplankton have evolved to grow calcium carbonate shells which are durable and protective, with rising CO 2 levels and lower pH levels in seawater demonstrated to affect the shell growth of various phytoplankton differently. − …”