Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine

The precipitation of calcium carbonate and calcium sulphate by isolated bacteria from seawater and real brine obtained in a desalination plant growth in culture media containing seawater and brine as mineral sources has been studied. However, only bioprecipitation was detected when the bacteria were grown in media with added organic matter. Biomineralization process started rapidly, crystal formation taking place in the beginning a few days after inoculation of media; roughly 90% of total cultivated bacteria showed. Six major colonies with carbonate precipitation capacity dominated bacterial community structure cultivated in heterotrophic platable bacteria medium. Taxonomic identification of these six strains through partial 16S rRNA gene sequences showed their affiliation with Gram-positiveBacillusandVirgibacillusgenera. These strains were able to form calcium carbonate minerals, which precipitated as calcite and aragonite crystals and showed bacterial fingerprints or bacteria calcification. Also, carbonic anhydrase activity was observed in three of these isolated bacteria. The results of this research suggest that microbiota isolated from sea water and brine is capable of precipitation of carbonate biominerals, which can occurin situwith mediation of organic matter concentrations. Moreover, calcium carbonate precipitation ability of this microbiota could be of importance in bioremediation of CO2and calcium in certain environments.

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Optimization of Calcium Carbonate Precipitation for Bacillus pasteurii

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.178-181.676 ◽

2012 ◽

Vol 178-181 ◽

pp. 676-679 ◽

Cited By ~ 1

Author(s):

Tao Duan ◽

Wen Kun Zhu

Keyword(s):

Calcium Carbonate ◽

Crystal Formation ◽

Carbonate Precipitation ◽

X Ray Diffraction ◽

Calcium Carbonate Precipitation ◽

Electron Microscopic ◽

Bacillus Pasteurii ◽

Scanning Electron Microscopic ◽

External Conditions ◽

Effects Of Temperature

The effects of temperature, pH, precipitation time, reactant concentration, the crystal formation additive on the yield of calcium carbonate precipitation induced by bacillus pasteurii were investigated through orthogonal test. The morphology and structure of the calcium carbonate were characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (IR) and powder X-ray diffraction (XRD). The results showed that the optimum conditions of calcium carbonate precipitation induced by bacillus pasteurii were temperature of 40oC, pH of 8, precipitation time of 3 d, Ca2+ of 1.5 mol/L, and Mg2+ of 0.05 mol/L. The crystal of calcium carbonate was calcites or mixture of calcites and vaterite. Its morphology and packing density were changed by different external conditions.

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Strain-Specific Ureolytic Microbial Calcium Carbonate Precipitation

Applied and Environmental Microbiology ◽

10.1128/aem.69.8.4901-4909.2003 ◽

2003 ◽

Vol 69 (8) ◽

pp. 4901-4909 ◽

Cited By ~ 245

Author(s):

Frederik Hammes ◽

Nico Boon ◽

Johan de Villiers ◽

Willy Verstraete ◽

Steven Douglas Siciliano

Keyword(s):

Calcium Carbonate ◽

Denaturing Gradient Gel Electrophoresis ◽

Gene Diversity ◽

Bacillus Sphaericus ◽

16S Rrna Genes ◽

Rrna Genes ◽

Crystal Formation ◽

Carbonate Precipitation ◽

Calcium Carbonate Precipitation ◽

Gradient Gel Electrophoresis

ABSTRACT During a study of ureolytic microbial calcium carbonate (CaCO3) precipitation by bacterial isolates collected from different environmental samples, morphological differences were observed in the large CaCO3 crystal aggregates precipitated within bacterial colonies grown on agar. Based on these differences, 12 isolates were selected for further study. We hypothesized that the striking differences in crystal morphology were the result of different microbial species or, alternatively, differences in the functional attributes of the isolates selected. Sequencing of 16S rRNA genes showed that all of the isolates were phylogenetically closely related to the Bacillus sphaericus group. Urease gene diversity among the isolates was examined by using a novel application of PCR-denaturing gradient gel electrophoresis (DGGE). This approach revealed significant differences between the isolates. Moreover, for several isolates, multiple bands appeared on the DGGE gels, suggesting the apparent presence of different urease genes in these isolates. The substrate affinities (Km ) and maximum hydrolysis rates (V max) of crude enzyme extracts differed considerably for the different strains. For certain isolates, the urease activity increased up to 10-fold in the presence of 30 mM calcium, and apparently this contributed to the characteristic crystal formation by these isolates. We show that strain-specific calcification occurred during ureolytic microbial carbonate precipitation. The specificity was mainly due to differences in urease expression and the response to calcium.

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