Precipitation of minerals by 22 species of moderately halophilic bacteria in artificial marine salts media: Influence of salt concentration

Abstract

Precipitation of minerals was shown by 22 species of moderately halophilic bacteria in both solid and liquid artificial marine salts media at different concentration and different Mg2+-to-Ca2+ ratio. Precipitation of minerals was observed for all the bacteria used. When salt concentration increased, the quantity and the size of bioliths decreased, the time required for precipitation being increased. The precipitated minerals were calcite, magnesian calcite, aragonite, dolomite, monohydrocalcite, hydromagnesite and struvite in variable proportions, depending on the bacterial species, the salinity and the physical state of the medium; the Mg content of the magnesian calcite also varied according to the same parameters. The precipitated minerals do not correspond exactly to those which could be precipitated inorganically according to the saturation indices. Scanning electron microscopy showed that the formation of the bioliths is initiated by grouping of calcified cells and that the dominant final morphologies were spherulitic with fibrous radiated interiors. It was demonstrated that moderately halophilic bacteria play an active role in the precipitation of carbonates and we hypothesize about this process of biomineralization.

Calcite Formation in Soft Coral Sclerites Is Determined by a Single Reactive Extracellular Protein

“…The solution from which crystals were precipitated contained 50 mM Mg 2ϩ and 10 mM Ca 2ϩ (i.e. a 5:1 ratio), which would strongly favor precipitation of only aragonite (31,32). However, two strong bands at 1086.9 cm Ϫ1 (v1) and 1415 cm Ϫ1 (v3) in the NFIR spectrum, corresponding to calcite, were detected (Fig.…”

Catalytic Biomineralization of Fluorescent Calcite by the Thermophilic Bacterium Geobacillus thermoglucosidasius

“…Calcite (calcium carbonate) precipitation is a well-known example of extracellular bacterial biomineralization. Certain species of marine bacteria have been shown to precipitate minerals in water supplemented with artificial marine salt media and differing ratios of Mg 2ϩ to Ca 2ϩ concentrations (20). Several groups have investigated the geobiochemical significance of the presence of calcium carbonate in seafloor sediments in terms of calcite formation by marine bacteria (17).…”

Precipitation of carbonates by bacteria isolated from wastewater samples collected in a conventional wastewater treatment plant

“…Numerous laboratory studies and observations in natural environments have demonstrated the bacterial precipitation of calcium carbonate (Rivadeneyra et al 1999(Rivadeneyra et al , 2000(Rivadeneyra et al , 2006bSánchez-Román et al 2007). One of the mechanisms of calcium carbonate precipitation most often proposed is that microorganisms produce NH 4 ?…”