Biological control of aragonite formation in stony corals
2017; American Association for the Advancement of Science; Volume: 356; Issue: 6341 Linguagem: Inglês
10.1126/science.aam6371
ISSN1095-9203
AutoresStanislas Von Euw, Qihong Zhang, Viacheslav Manichev, Nagarajan Murali, Juliane Groß, L. C. Feldman, Torgny Gustafsson, Carol R. Flach, Richard Mendelsohn, Paul G. Falkowski,
Tópico(s)Cephalopods and Marine Biology
ResumoLittle is known about how stony corals build their calcareous skeletons. There are two prevailing hypotheses: that it is a physicochemically dominated process and that it is a biologically mediated one. Using a combination of ultrahigh-resolution three-dimensional imaging and two-dimensional solid-state nuclear magnetic resonance (NMR) spectroscopy, we show that mineral deposition is biologically driven. Randomly arranged, amorphous nanoparticles are initially deposited in microenvironments enriched in organic material; they then aggregate and form ordered aragonitic structures through crystal growth by particle attachment. Our NMR results are consistent with heterogeneous nucleation of the solid mineral phase driven by coral acid-rich proteins. Such a mechanism suggests that stony corals may be able to sustain calcification even under lower pH conditions that do not favor the inorganic precipitation of aragonite.
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