Search results for "Biominerals"
showing 3 items of 3 documents
Inorganic/Organic interface in biominerals : unveiling the complex structure of two calcitic biomineral models, the red coral Corallium rubrum and th…
2022
Biominerals are organo-minerals structures produced by living systems. Since the Cambrian, they contribute to the adaptation of living organisms to different environments by fulfilling a variety of combined functions that go along with adapted morphologies. One of the aims of biomineralization is to understand how organisms "sculpt" these complex morphologies, in particular at nano and molecular scales. The aim of this PhD work was to understand the complex relationships between the organic and mineral phases. To this end, I focused my analyses on two calcitic biomineral models: 1) the red coral Corallium rubrum and 2) the prismatic shell of the Mediterranean fan mussel Pinna nobilis. My wo…
Evolution and biomineralization of pteropod shells
2021
12 pages; International audience; Shelled pteropods, known as sea butterflies, are a group of small gastropods that spend their entire lives swimming and drifting in the open ocean. They build thin shells of aragonite, a metastable polymorph of calcium carbonate. Pteropod shells have been shown to experience dissolution and reduced thickness with a decrease in pH and therefore represent valuable bioindicators to monitor the impacts of ocean acidification. Over the past decades, several studies have highlighted the striking diversity of shell microstructures in pteropods, with exceptional mechanical properties, but their evolution and future in acidified waters remains uncertain. Here, we re…
Biochemical characteristics of the soluble organic matrix from the shell of three recent terebratulid brachiopod species.
2008
7 pages; International audience; To build their shells, brachiopods secrete a mixture of proteins and polysaccharides, collectively called the organic matrix. This matrix mediates the calcification process by allowing crystal nucleation followed by elongation and finally by stopping the crystal growth. Ultimately, the matrix controls the different microstructures formed. Brachiopod shells are composites with both organic and inorganic constituents intimately associated. This work represents an attempt to characterize the matrices using two combined approaches: (1) scanning electron microscopy for localization within the shell, (2) analysing extracted matrices at the molecular level to deter…