title: Biomineralization of carbonates by Halobacillus trueperi in solid and liquid media with different salinities.
abstract: We investigated the precipitation of carbonates by Halobacillus trueperi in both solid and liquid media at different salt concentrations and different magnesium/calcium ratios. H. trueperi precipitated at all assayed salt concentrations. When salt concentration increased, the quantity and the size of bioliths decreased and the time required increased. The precipitated minerals (determined by X-ray diffraction) were calcite, magnesium calcite and monohydrocalcite in variable proportions depending on the salinity and the physical state of the medium; the magnesium content of the magnesium calcites also varied with regard to the culture type. According to the saturation indices other minerals could also precipitate. Scanning electron microscopy showed that dominant morphologies of the bioliths were spherulitic with fibrous radiated interiors. We show that H. trueperi plays an active role in the precipitation of carbonates and we hypothesize about this process of biomineralization.
authors.affiliation: Department of Microbiology, University of Granada, Spain.
authors.forename: María Angustias
authors.initials: MA
authors.lastname: Rivadeneyra
authors.forename: Jesús
authors.initials: J
authors.lastname: Párraga
authors.forename: Rafael
authors.initials: R
authors.lastname: Delgado
authors.forename: Alberto
authors.initials: A
authors.lastname: Ramos-Cormenzana
authors.forename: Gabriel
authors.initials: G
authors.lastname: Delgado
mesh_terms: D001406:Bacillaceae / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002119:Calcium Carbonate / Q000378:metabolism; D002254:Carbonates / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry*; D008274:Magnesium / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D012492:Salts / Q000378:metabolism
chemical_list: D002254:Carbonates; D003470:Culture Media; D012492:Salts; D002119:Calcium Carbonate; D008274:Magnesium; D002118:Calcium