scholarly journals Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 585 ◽  
Author(s):  
Zuozhen Han ◽  
Xiao Gao ◽  
Hui Zhao ◽  
Maurice Tucker ◽  
Yanhong Zhao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbonic Anhydrase ◽  
Bacillus Licheniformis ◽  
Extracellular Polymeric Substances ◽  
Carbonate Minerals ◽  
Carbonate Sedimentology ◽  
Molar Ratios ◽  
Close Relationship ◽  
Ph Increase ◽  
Mineral Aggregates

Biomineralization has become a research hotspot and attracted widespread attention in the field of carbonate sedimentology. In this study, precipitation of carbonate minerals was induced by Bacillus licheniformis DB1-9 bacteria, (identity confirmed with its phylogenetic tree), to further explore the biomineralization mechanisms. During experiments, lasting up to 24 days with varying Mg/Ca molar ratios and regular monitoring of conditions, ammonia and carbonic anhydrase are released by the bacteria, resulting in a pH increase. Carbonic anhydrase could have promoted carbon dioxide hydration to produce bicarbonate and carbonate ions, and so promoted supersaturation to facilitate the precipitation of carbonate minerals. These include rhombohedral, dumbbell-shaped, and elongated calcite crystals; aragonite appears in the form of mineral aggregates. In addition, spheroidal and fusiform minerals are precipitated. FTIR results show there are organic functional groups, such as C–O–C and C=O, as well as the characteristic peaks of calcite and aragonite; these indicate that there is a close relationship between the bacteria and the minerals. Ultrathin slices of the bacteria analyzed by HRTEM, SAED, EDS, and STEM show that precipitate within the extracellular polymeric substances (EPS) has a poor crystal structure, and intracellular granular areas have no crystal structure. Fluorescence intensity and STEM results show that calcium ions can be transported from the outside to the inside of the cells. This study provides further insights to our understanding of biomineralization mechanisms induced by microorganisms.

scholarly journals The Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

2018 ◽  
Author(s):  
Zuozhen Han ◽  
Xiao Gao ◽  
Hui Zhao ◽  
Maurice E. Tucker ◽  
Yanhong Zhao ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Carbonic Anhydrase ◽  
Bacillus Licheniformis ◽  
Calcium Ions ◽  
Hydration Reaction ◽  
Magnesium Ions ◽  
Calcium Carbonate Precipitation ◽  
Carbonate Sedimentology ◽  
Molar Ratios ◽  
Liquid Culture Medium

Biomineralization has become a research hotspot and attracted widespread attention in the field of carbonate sedimentology. In this study, Bacillus licheniformis DB1-9 was used to induce the calcium carbonate precipitation at different magnesium calcium molar ratios in the laboratory to further explore the biomineralization mechanism. Phylogenetic tree shows that the bacteria belongs to Bacillus licheniformis species. The ammonia and carbonic anhydrase can be released by this bacteria, resulting in the pH increase, and the carbonic anhydrase can also promote the hydration reaction of carbon dioxide and subsequently produce the bicarbonate and carbonate ions to elevate the supersaturation of calcium carbonate in the liquid culture medium to facilitate the precipitation of carbonate minerals. The calcites have a shape of rhombohedron, dumbell, and elongation, and aragonite often appears in the form of mineral aggregates, besides that there are also the spherical and the fusiform minerals. FTIR result shows there are some organic functional groups, such as C-O-C and C=O, beside of the characteristic peaks of the calcite and the aragonite, indicating that microbial metabolism is closely related to the mineral formation. The superthin slices of the bacteria analyzed by HRTEM, SAED, EDS and STEM show that the surface and EPS can adsorb a large number of calcium ions and magnesium ions and EPS may act as the nucleation sites, what’s more, the intracellular nanometer-scale sphere areas show the amorphous structures, and the intracellular calcium ions and magnesium ions suggeste that they can be transported from the outside to inside the cell by diffusion along the concentration grade from high to low. This study may provide some references to further understand the biomineralization mechanism induced by microorganisms in the laboratory and the field, and also helps to explore the reason of the transition of calcite sea to aragonite sea in the geological history.

scholarly journals The Significant Role of Different Magnesium: Carbonate Minerals Induced by Moderate Halophile Staphylococcus epidermis Y2

2018 ◽  
Author(s):  
Zuozhen Han ◽  
Wenwen Yu ◽  
Yanhong Zhao ◽  
Maurice E. Tucker ◽  
Huaxiao Yan
Keyword(s):  
Carbonic Anhydrase ◽  
Magnesium Sulfate ◽  
Significant Role ◽  
Magnesium Chloride ◽  
Carbonate Minerals ◽  
Chloride Medium ◽  
Carbonate Sedimentology ◽  
Moderate Halophile ◽  
Bicarbonate Ions ◽  
Sulfate Medium

Carbonate precipitation induced by microorganism has become a hot spot in the field of carbonate sedimentology, while the effect of different magnesium on biominerals has rarely been studied. Therefore, magnesium sulfate and magnesium chloride were used to investigate the significant role played on carbonate minerals. In this study, Staphylococcus epidermidis Y2 was isolated and identified by 16S rDNA homology comparison. The ammonia, pH, carbonic anhydrase, carbonate and bicarbonate ions were investigated. The mineral phase, morphology and elemental composition were analyzed by XRD and SEM-EDS. The ultrathin slices of bacteria were analyzed by HRTEM-SAED and STEM. The result showed that this bacterium could release ammonia and carbonic anhydrase to increase pH, and elevate the supersaturation via a large number of carbonate and bicarbonate ions released through carbon dioxide hydration catalyzed by carbonic anhydrase. The crystal cell density of monohydrocalcite was lower in magnesium chloride medium than that in magnesium sulfate medium. The crystal grew in a mode of spiral staircas in magnesium sulfate medium, while in a concentric circular pattern in magnesium chloride medium. There was no obvious intracellular biomineralization. This study may be helpful to further understand the biomineralization mechanism, may also provide some references for the reconstruction of paleogeological environment.

scholarly journals Bio-Precipitation of Calcium and Magnesium Ions through Extracellular and Intracellular Process Induced by Bacillus Licheniformis SRB2

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 526 ◽  
Author(s):  
Yanyang Zhao ◽  
Huaxiao Yan ◽  
Jingxuan Zhou ◽  
Maurice E. Tucker ◽  
Mei Han ◽  
...  
Keyword(s):  
Bacillus Licheniformis ◽  
Extracellular Polymeric Substances ◽  
Magnesium Ions ◽  
Molar Ratios ◽  
Charged Amino Acids ◽  
Organic Functional Groups ◽  
Intracellular Process ◽  
Calcium And Magnesium ◽  
Environmentally Friendly Method ◽  
Calcium And Magnesium Ions

Removal of calcium and magnesium ions through biomineralization induced by bacteria has been proven to be an effective and environmentally friendly method to improve water quality, but the process and mechanism are far from fully understood. In this study, a newly isolated probiotic Bacillus licheniformis SRB2 (GenBank: KM884945.1) was used to induce the bio-precipitation of calcium and magnesium at various Mg/Ca molar ratios (0, 6, 8, 10, and 12) in medium with 30 g L−1 sodium chloride. Due to the increasing pH and HCO3− and CO32− concentrations caused by NH3 and carbonic anhydrase, about 98% Ca2+ and 50% Mg2+ were precipitated in 12 days. The pathways of bio-precipitation include extracellular and intracellular processes. Biominerals with more negative δ13C values (−16‰ to −18‰) were formed including calcite, vaterite, monohydrocalcite, and nesquehonite with preferred orientation. The nucleation on extracellular polymeric substances was controlled by the negatively charged amino acids and organic functional groups. The intracellular amorphous inclusions containing calcium and magnesium also contributed to the bio-precipitation. This study reveals the process and mechanism of microbial desalination for the removal of calcium and magnesium, and provides some references to explain the formation of the nesquehonite and other carbonate minerals in a natural and ancient earth surface environment.

scholarly journals The Structural Dimorphism of Lanthanum Oxide Fluoride Selenide La2OF2Se

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 435 ◽  
Author(s):  
Buyer ◽  
Grossholz ◽  
Schleid
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Lanthanum Oxide ◽  
Solid State Reactions ◽  
Space Group ◽  
Molar Ratios ◽  
Type Form ◽  
Close Relationship ◽  
Lamellar Crystals

The new colorless lanthanum oxide fluoride selenide La2OF2Se could be synthesized via solid-state reactions in two different structure types. Lamellar crystals of A-La2OF2Se were obtained from mixtures of La, LaF3, La2O3 and Se in molar ratios of 2:2:1:3 with NaCl as flux for seven days in silica-protected sealed tantalum capsules at 850 °C. Needle-shaped crystals of BLa2OF2Se emerged from reactions of the same educt mixtures in molar ratios of 6:4:4:9 scheduled to produce La6O4F4Se3 with CsI as flux for four days in niobium ampoules at 700 °C. The Atype form of La2OF2Se crystallizes in the trigonal space group R3m with a = 418.13(3) and c = 4478.2(4) pm for Z = 6, whereas the Btype form is hexagonal (space group: P63/m) with a = 1396.82(9) and c = 401.08(3) pm for Z = 6. The crystal structure of A-La2OF2Se shows a close relationship to the fluoride-free La2O2Se and the oxygen-free La2F4Se. It can even be discussed as 1:1 intergrowth variety, since it contains the [LaO4Se3]11− and [LaF7Se3]10− polyhedra typical for the ternaries. B-La2OF2Se appears to be structurally very similar to La6O2F8Se3 in displaying [LaO3FSe4]12− and [LaOF6Se2]9− polyhedra. With 6.039 versus 6.036 g/cm³ the B-type form of La2OF2Se is slightly denser than the A-type variant.

Crystal Structure of F65A/Y131C-Methylimidazole Carbonic Anhydrase V Reveals Architectural Features of an Engineered Proton Shuttle†

Biochemistry ◽  
2002 ◽  
Vol 41 (8) ◽  
pp. 2485-2491 ◽  
Author(s):  
Kevin M. Jude ◽  
S. Kirk Wright ◽  
Chingkuang Tu ◽  
David N. Silverman ◽  
Ronald E. Viola ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbonic Anhydrase ◽  
Architectural Features

Modification of a metal ligand in carbonic anhydrase: Crystal structure of His94 →Glu human isozyme II

FEBS Letters ◽  
1994 ◽  
Vol 352 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Yafeng Xue ◽  
Bengt-Harald Jonsson ◽  
Anders Liljas ◽  
Sven Lindskog
Keyword(s):  
Crystal Structure ◽  
Carbonic Anhydrase ◽  
Metal Ligand

Crystal structure of the most catalytically effective carbonic anhydrase enzyme known, SazCA from the thermophilic bacterium Sulfurihydrogenibium azorense

2015 ◽  
Vol 25 (9) ◽  
pp. 2002-2006 ◽  
Author(s):  
Giuseppina De Simone ◽  
Simona Maria Monti ◽  
Vincenzo Alterio ◽  
Martina Buonanno ◽  
Viviana De Luca ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbonic Anhydrase ◽  
Thermophilic Bacterium ◽  
Carbonic Anhydrase Enzyme
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