Coccolithophores are an important group of marine phytoplankton, characterised by their ability to produce a covering of calcium carbonate coccoliths. Many strains of the abundant coccolithophore species Emiliania huxleyi have become non-calcifying when maintained in laboratory culture. The loss of calcification appears to have surprisingly little impact on the the ability of E. huxleyi to grow in the lab, suggesting that coccolithophores do not need to calcify. However, research conducted by Charlotte Walker during her PhD at the MBA has shown that another abundant species, Coccolithus braarudii, has an absolute requirement to maintain its covering of coccoliths. When the ability to calcify was disrupted in C. braarudii, cells stopped dividing and the cultures failed to grow. The results suggest that E. huxleyi is not typical of all coccolithophores and that some species have an absolute requirement for calcification, which could influence their response to future ocean acidification.
The research has been published in New Phytologist.
Coccolithus braarudii cells treated with the silicon analogue germanium to disrupt coccolith formation