title: Amorphous Ca-phosphate precursors for Ca-carbonate biominerals mediated by Chromohalobacter marismortui.
abstract: 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.
authors.affiliation: Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.
authors.forename: María Angustias
authors.initials: MA
authors.lastname: Rivadeneyra
authors.forename: Agustín
authors.initials: A
authors.lastname: Martín-Algarra
authors.forename: Mónica
authors.initials: M
authors.lastname: Sánchez-Román
authors.forename: Antonio
authors.initials: A
authors.lastname: Sánchez-Navas
authors.forename: José Daniel
authors.initials: JD
authors.lastname: Martín-Ramos
mesh_terms: 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
chemical_list: D002130:Calcium Phosphates; D003470:Culture Media; D008903:Minerals; C020243:calcium phosphate; D002119:Calcium Carbonate