Bio-precipitation of Calcite with Preferential Orientation Induced bySynechocystissp. PCC6803

Abstract

This article presents a research study on the deposition process of Ca 2C induced by Synechocystis sp. PCC6803 in BG11 liquid medium with different Ca 2C concentrations and different pH. The changes of Ca 2C concentrations were measured by using atomic absorption method and the corresponding dynamical models were studied. Minerals and cells were analyzed by high resolution transmission electron microscope, selected area electron diffraction, scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffraction. The selected area electron diffraction patterns were analyzed by Digital Micrograph 3.7 software. The result showed that Ca 2C concentrations decreased faster in the experimental group. The changes of calcium carbonate precipitation were fitting to an exponential model. PH 7 and Ca 2C concentration of 1.5 g/L were most conducive to calcium carbonate precipitation in the corresponding gradient range. The result of high-resolution transmission electron microscopy showed that minerals in the experimental group differed obviously from that of the control group in the surface morphology, but both of them were calcites. It also showed that a certain number of minute calcites adhesion to the outer surfaces of S. PCC6803 cells. The result of scanning electron microscopy displayed that many sunken holes emerged on the surfaces of the prismatic calcium carbonate minerals. The results of X-ray diffraction proved that minerals induced by S. PCC6803 were calcites with preferential orientation. This article discusses the process of carbonate formation and the possible role played by S. PCC6803. It may be useful to further study the mechanism of microbial carbonates deposition in the field of geology.

Genomic and Transcriptomic Insights into Calcium Carbonate Biomineralization by Marine Actinobacterium Brevibacterium linens BS258

“…Samples were taken by immersing grids coated with a carbon film for 10 s in prepared bacterial suspension and dried several minutes at room temperature. The possible precipitated carbonate observed with TEM was further confirmed using Selected Area Electron Diffraction (SAED) (Han et al, 2014). …”

“…To measure the concentrations of Cd 2+ and Pb 2+ at the end of the incubation, the supernatant was collected by centrifugation (13400 × g , 2 min), and was digested completely and diluted with Milli-Q water. The concentrations of Cd 2+ and Pb 2+ in the solution were measured with an inductively coupled plasma source mass spectrometer (Optima 7300 DV, PerkinElmer) (Han et al, 2014). …”

Bio-Precipitation of Carbonate and Phosphate Minerals Induced by the Bacterium Citrobacter freundii ZW123 in an Anaerobic Environment

“…Cyanobacteria have also been widely used as experimental strains to induce mineral precipitation. Han et al [18] reported a clear preferential orientation in the calcite induced by Synechocystis sp. PCC6803.…”

The Characterization of Intracellular and Extracellular Biomineralization Induced bySynechocystis sp. PCC6803 Cultured under Low Mg/Ca Ratios Conditions

“…Therefore, the contents of magnesium in carbonate (Young and Galy 2004). In low Mg/Ca ratio fluid, such as basin, swamp, Mg-calcite with equal size could be formed, while in high Mg/Ca ratio fluid, such as sea water or salty lake, high-Mg calcites and aragonite could often be formed (Bener et al 1975;Fernandez-Diaz et al 1996;Han et al 2014). …”

“…This microorganism itself and its extracellular polymeric substances (EPS) could be regarded as suppliers for nucleation sites, which had played an important role in mineral nucleation and Han et al (2014) found that the Synechocystis sp.…”