Precipitation of calcite induced by Synechocystis sp. PCC6803

• Published in: World journal of microbiology & biotechnology Vol. 29; no. 10; pp. 1801 - 1811
• Main Authors: Han, Zuozhen, Yan, Huaxiao, Zhou, Shixue, Zhao, Hui, Zhang, Yan, Zhang, Ningning, Yao, Chuankai, Zhao, Lin, Han, Chunyan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.10.2013; Springer Nature B.V
• Subjects: Amino acids; Applied Microbiology; Biochemistry; Biomedical and Life Sciences; Biotechnology; Bones; Calcite; Calcium Carbonate - chemistry; Calcium Carbonate - metabolism; Calcium chloride; Calcium Chloride - metabolism; Chemical elements; Chemical Precipitation; Chemistry; Crystallization; Crystals; Culture Media - chemistry; Cyanobacteria; Environmental Engineering/Biotechnology; Geobiology; Hydrogen-Ion Concentration; Ions; Lasers; Life Sciences; Microbiology; Microscopy, Confocal; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Mineralization; Minerals; Original Paper; Scanning electron microscopy; Science; Spectrometry, X-Ray Emission; Spectrum analysis; Studies; Synechocystis; Synechocystis - metabolism; Synechocystis - ultrastructure; Teeth; Transmission electron microscopy; X-Ray Diffraction; United States > US; Biomineralization; X-ray diffraction (XRD); Calcite; Transmission electron microscopy (TEM); sp. PCC6803; Laser confocal scanning microscope (LCSM)
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/s11274-013-1341-1

Calcite with laminate structure was successfully prepared by culturing Synechocystis sp. PCC6803 with different concentrations of calcium chloride (CaCl 2 ) in BG11 media. S. PCC6803 was examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser confocal scanning microscope (LCSM) and energy dispersive spectroscopy (EDS). The effects of Ca 2+ concentrations and pH values on calcification were investigated and the micro morphs of the CaCO 3 crystals were observed by means of SEM. These results showed that CaCO 3 crystals could be more easily formed with increasing the concentration of CaCl 2 in S. PCC6803 culture solution. S. PCC6803 could largely bind calcium ions, most of which were present in extracellular polymeric substances and on the cell wall. Inside the cells there were a lot of circular areas rich in calcium ions without the crystallization of calcium. Some cells produced a thicker gelatinous sheath outside of the translucent organic thin layer. And the cells inside also produced major changes that the original chloroplasts were almost transformed into starch grains whose sizes were from 0.5 to 1 μm with relatively uniform in sizes. At the same time the cell sizes significantly reduced to only about 8–9 μm almost changing to half of its original diameters. The calcite crystals with a highly preferred orientation induced by S. PCC6803 were observed with X-ray diffraction (XRD). A critical implication was that S. PCC6803 could induce bio-calcification and then mediate the further growth of CaCO 3 crystals in the biological system.