scholarly journals Biomineralization of Carbonate Minerals Induced by the Halophilic Chromohalobacter israelensis under High Salt Concentrations: Implications for Natural Environments

2017 ◽  
Author(s):  
Zuozhen Han ◽  
Dan Li ◽  
Hui Zhao ◽  
Huaxiao Yan ◽  
Peiyuan Li
Keyword(s):  
Electron Microscopy ◽  
Extracellular Polymeric Substances ◽  
Ph Value ◽  
Halophilic Bacteria ◽  
High Salt ◽  
Energy Dispersive ◽  
Control Group ◽  
Carbonate Precipitation ◽  
Carbonate Minerals ◽  
X Ray

The mechanism underlying microbiologically induced carbonate precipitation have not been thoroughly characterized, although numerous scholars and experts have specifically investigated questions regarding minerals induced by bacteria. The study of the precipitation of carbonate minerals induced by halophilic bacteria has aroused wide concern. The present study aimed to investigate the characterization and process of biomineralization in high salt systems by a halophilic bacterium, Chromohalobacter israelensis strain LD532 (GenBank: KX766026), which was isolated from the Yinjiashan Saltern in China. Carbonate minerals induced by LD532 were investigated in several sets of comparative experiments that employed magnesium sulfate and magnesium chloride as Mg resources. Magnesium calcite and aragonite were induced by LD532 bacteria, whereas these minerals did not appear in the control group. The mineral phases, micromorphologies, and crystal structures were analysed using X-ray powder diffraction, scanning electron microscopy, and energy dispersive X-ray detection. The carbonic anhydrase and urease secreted by strain LD532 through metabolism increased the pH value of the liquid medium and promoted the process of carbonate precipitation. Further study using high resolution transmission electron microscopy, energy dispersive X-ray detection and analysis of ultrathin slices showed that the nucleation sites of carbonate minerals were located on extracellular polymeric substances and the membranes of intracellular vesicles of LD532 bacteria, which provided favourable conditions for the growth of carbonate mineral crystals. The morphologies and compositions of minerals formed in solutions of MgSO4 and MgCl2 display significant differences, indicating that different sources of Mg2+ may also affect the physiological and biochemical activities of microorganisms and thus mineral deposition. This study will be of some interest for the interpretation of carbonate biomineralization in natural salt environments and has some value as a reference in understanding sedimentary carbonates in ancient marine environments, such as tidal flats.

scholarly journals Biomineralization of Carbonate Minerals Induced by Halophilic Chromohalobacter israelensis in High Salt Concentration: Implications for Natural Environments

2017 ◽  
Author(s):  
Zuozhen Han ◽  
Dan Li ◽  
Huaxiao Yan ◽  
Peiyuan Li
Keyword(s):  
Halophilic Bacteria ◽  
Reference Value ◽  
Halophilic Bacterium ◽  
High Salt ◽  
Energy Dispersive ◽  
Control Group ◽  
Natural Environments ◽  
Carbonate Precipitation ◽  
Carbonate Minerals ◽  
X Ray

High salt environment was widespread in modern and geological record, and sedimentation induced by microbes in these systems was an important part of sedimentary minerals and rocks. The mechanism of microbiologically induced carbonate precipitation has not been solved thoroughly although numerous scholars and experts have made specifically research of the problems with respect to minerals induced by bacteria. The study of carbonate minerals induced by Halophilic bacteria has aroused wide concern. The present study was aim to investigate the characterization and process of biomineralization in the high salt system, a Halophilic bacterium, Chromohalobacter israelensis LD532 strain (Genbank: KX766026), which isolated from Yinjiashan Saltern of China, was selected as an object to induce carbonate minerals. Carbonate minerals induced by LD532 were investigated in several comparative experimental sets with Mg resources of magnesium sulfate and magnesium chloride. Magnesium calcite and aragonite were induced by LD532 bacteria while these minerals were not in the control group. The mineral phases, micromorphologies, and crystal structures were analyzed using X-ray powder diffraction, scanning electron microscope, and energy dispersive X-ray detector. Carbonic anhydrase and urease secreted by strain LD532 through metabolism promoted the pH values of the liquid medium and the process of carbonate precipitation. Further study proved that the nucleation sites of partial carbonate nucleus were located on the extracellular polymeric substance and the membrane of intracellular vesicles of LD532 bacteria by high resolution transmission electron microscopy, energy dispersive X-ray detector and ultrathin slices analysis, which provided favorable conditions for the growth of carbonate mineral crystals. The morphology and composition of minerals formed in MgSO4 and MgCl2 solution have significant differences, indicating that different sources of Mg2+ could also affect the physiological and biochemical activities of microorganisms and then affect the mineral deposition. The accomplished study is of certain interest for interpretation of the carbonates biomineraliazation in natural salt environment, and has a certain reference value in understand of the sedimentary carbonates in ancient marine environment like evaporated tidal flat.

Uranium association with halophilic and non-halophilic bacteria and archaea

2004 ◽  
Vol 92 (8) ◽  
Author(s):  
Arokiasamy J. Francis ◽  
J. B. Gillow ◽  
Cleveland J. Dodge ◽  
R. Harris ◽  
T. J. Beveridge ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
New Mexico ◽  
Pilot Plant ◽  
Halophilic Bacteria ◽  
Energy Dispersive ◽  
Waste Isolation Pilot Plant ◽  
X Ray ◽  
Transmission Electron ◽  
Uranium Accumulation

SummaryWe determined the association of uranium with bacteria isolated from the Waste Isolation Pilot Plant (WIPP), Carlsbad, New Mexico, and compared this with known strains of halophilic and non-halophilic bacteria and archaea. Examination of the cultures by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) showed uranium accumulation extracellularly and/or intracellularly to a varying degree. In

Structural Characterization of Gallbladder Stones Using Energy Dispersive X-ray Spectroscopy and X-ray Diffraction

2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Major Health Problem ◽  
X Ray ◽  
Gallbladder Stones ◽  
Pure Cholesterol ◽  
Scanning Electron

Aim and Objective: Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. Material and Method: Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. Results: The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. Conclusion: The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.

scholarly journals Hydrothermal Synthesis of Various Shape-Controlled Europium Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 529
Author(s):  
Hongjuan Zheng ◽  
Kongjun Zhu ◽  
Ayumu Onda ◽  
Kazumichi Yanagisawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ph Value ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Hydrothermal Reactions ◽  
Starting Solution ◽  
Initial Ph ◽  
Shape Controlled ◽  
Scanning Electron

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.

Identification of Nd163 phase in melt-textured NdBa2Cu3O7−δ bulk samples

2003 ◽  
Vol 18 (9) ◽  
pp. 2050-2054 ◽  
Author(s):  
Marcello Gombos ◽  
Vicente Gomis ◽  
Anna Esther Carrillo ◽  
Antonio Vecchione ◽  
Sandro Pace ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Room Temperature ◽  
Polarized Light ◽  
Energy Dispersive ◽  
X Ray ◽  
Spontaneous Formation ◽  
The Stability ◽  
Scanning Electron

In this work, we report on the observation of Nd1Ba6Cu3O10,5 (Nd163) phase of the NdBaCuO system in melt-textured Nd123 bulk samples grown from a mixture of Nd123 and Nd210 phase powders. The observation was performed with polarized light optical microscopy and scanning electron microscopy–energy dispersive x-ray analyses. Images of the identified phase crystals show an aspect quite different from Nd422 crystals. Unexpectedly, Nd163 was individuated, even in “pure” Nd123 samples. Moreover, after long exposure to air, Nd163 disappeared completely in samples synthesized from powders containing Nd210. Thermogravimetry analyses of powders show that the stability of this phase in air is limited to temperatures higher than 900 °C, so Nd163 is unstable and highly reactive at room temperature. Moreover, an explanation of the observation of Nd163 in Nd210 free samples, based on the spontaneous formation of Nd163 phase in a Nd123 melt, is proposed.

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