Amorphous Ca-phosphate precursors for Ca-carbonate biominerals mediated by Chromohalobacter marismortui

ISME J. 2010 Jul;4(7):922-32. doi: 10.1038/ismej.2010.17. Epub 2010 Feb 25.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Carbonate / chemistry*
  • Calcium Phosphates / chemistry*
  • Chemical Precipitation
  • Chromohalobacter / chemistry*
  • Chromohalobacter / classification
  • Chromohalobacter / growth & development
  • Culture Media
  • Hydrogen-Ion Concentration
  • Microscopy, Electron, Scanning
  • Minerals / chemistry*
  • X-Ray Diffraction

Substances

  • Calcium Phosphates
  • Culture Media
  • Minerals
  • calcium phosphate
  • Calcium Carbonate