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BP: Fachverband Biologische Physik

BP 9: Bioimaging

BP 9.5: Talk

Tuesday, September 6, 2022, 10:45–11:00, H16

Understanding calcareous biomineralization on the nanoscale through in-vivo growth imaging by x-ray nanodiffraction — •Tilman Grünewald¹, Jeremie Vidal-Dupiol², Julien Duboisset¹, Bruno Petton³, Jacqueline Legrand³, Michael Sztucki⁴, Manfred Burghammer⁴, and Virginie Chamard¹ — ¹Institut Fresnel, Marseille, France — ²Ifremer, Montpellier, France — ³Ifremer, Plouzané, France — ⁴ESRF, Grenoble, France

Biomineralized tissues combine properties such as low weight with high-strength and are formed from abundant atoms via low-energy processes. However, the nanostructural formation process of biominerals is not well understood, relying on post-mortem investigations of the bivalve growth edge [1]. Insights by in-vivo experiments requires studying a live organism in its environment at the crystalline level with sub-um spatial resolution. The associated problems have been overcome by 4th generation synchrotrons, enabling faster measurements.

Here, an experimental approach we developed and validated is outlined, enabling us to observe the first nanoscale-resolved, temporal follow-up of the shell growth in a living, mineralizing Crassostrea gigas oyster shell by nanofocus x-ray Bragg diffraction.

We show that crystallization occurs without the presence of the animal mantle, over several hours and follows a layer-by-layer deposition scheme with slightly misaligned grains. These results imply a cyclic crystallization, driven by a physico-chemical mechanism. This provides the animal with an efficient way of building its shell.

[1] Duboisset et al. 10.1016/j.actbio.2022.01.024