Amorphous Ca-phosphate precursors for Ca-carbonate biominerals mediated by Chromohalobacter marismortui.
Although diverse microbial metabolisms are known to induce the precipitation of carbonate minerals, the mechanisms involved in the bacterial mediation, in particular nucleation, are still debated. The study of aragonite precipitation by Chromohalobacter marismortui during the early stages (3-7 days) of culture experiments, and its relation to bacterial metabolic pathways, shows that: (1) carbonate nucleation occurs after precipitation of an amorphous Ca phosphate precursor phase on bacterial cell surfaces and/or embedded in bacterial films; (2) precipitation of this precursor phase results from local high concentrations of PO(4)(3-) and Ca(2+) binding around bacterial cell envelopes; and (3) crystalline nanoparticles, a few hundred nanometres in diametre, form after dissolution of precursor phosphate globules, and later aggregate, allowing the accretion of aragonite bioliths.
Rivadeneyra
María Angustias
MA
Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.
Martín-Algarra
Agustín
A
Sánchez-Román
Mónica
M
Sánchez-Navas
Antonio
A
Martín-Ramos
José Daniel
JD
D002119:Calcium Carbonate / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D011232:Chemical Precipitation; D055353:Chromohalobacter / Q000737:chemistry* / Q000145:classification / Q000254:growth & development; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry*; D014961:X-Ray Diffraction
D002130:Calcium Phosphates; D003470:Culture Media; D008903:Minerals; C020243:calcium phosphate; D002119:Calcium Carbonate