Excited to share our latest preprint live today on BiorXiv titled “Guardians of the cell: coccosphere prevents opportunitistic bacteria attack in heavy calcifying coccolithophore” . This work was led by Sophie Zweifel, a PhD student in the Stocker Lab, and forms the final exciting chapter of her doctoral work, with a scheduled defense upcoming later this autumn.

Coccolithophores, such as Geophryocapsa huxleyi (formally Emiliania huxleyi), follow a biphasic lifestyle, switching from a heavily-calcified diploid morphotype, to a motile but less-calcified haploid form. This species is responsible for the kilometre-scale algal bloom events visible from space (and often seen in the media!), and one of the most important oceanic primary producers. The role of the coccosphere has been heavily debated, and growing evidence suggests how different species have adapted their coccosphere to carry out highly specific tasks. In the case of Coccolithus braarudii, the dominant calcifier in subpolar regions such as the North Atlantic, we show that the coccosphere prevents cell death from opportunistic bacterial attack, most likely by preventing bacterial attachment to the vulnerable cell body.

This was very exciting work to be involved in that pulled together microscopy, microfluidics, microbiology in a comprehensive experimental study, and we’re delighted to share the preprint with you today! Even more so, this work brings together the final results from Sophie’s doctoral studies, and we’re looking forward to her upcoming thesis submission and defense this autumn!