scholarly journals In Situ Analysis of Sulfur Species in Sulfur Globules Produced from Thiosulfate by Thermoanaerobacter sulfurigignens and Thermoanaerobacterium thermosulfurigenes

2007 ◽  
Vol 189 (20) ◽  
pp. 7525-7529 ◽  
Author(s):  
Yong-Jin Lee ◽  
Alexander Prange ◽  
Henning Lichtenberg ◽  
Manfred Rohde ◽  
Mona Dashti ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Purple Sulfur Bacteria ◽  
Sulfur Species ◽  
Edge Structure ◽  
X Ray ◽  
Sulfur Bacteria ◽  
End Groups ◽  
Sulfur Globules ◽  
X Ray Absorption

ABSTRACT The Firmicutes Thermoanaerobacter sulfurigignens and Thermoanaerobacterium thermosulfurigenes convert thiosulfate, forming sulfur globules inside and outside cells. X-ray absorption near-edge structure analysis revealed that the sulfur consisted mainly of sulfur chains with organic end groups similar to sulfur formed in purple sulfur bacteria, suggesting the possibility that the process of sulfur globule formation by bacteria is an ancient feature.

scholarly journals X-Ray Absorption Spectroscopy as a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited

2008 ◽  
Vol 190 (19) ◽  
pp. 6376-6383 ◽  
Author(s):  
Graham N. George ◽  
Manuel Gnida ◽  
Dennis A. Bazylinski ◽  
Roger C. Prince ◽  
Ingrid J. Pickering
Keyword(s):  
Absorption Spectroscopy ◽  
Chemical Nature ◽  
Detection Methods ◽  
Intact Cells ◽  
X Ray ◽  
Sulfur Bacteria ◽  
Sulfur Globules ◽  
Original Question ◽  
X Ray Absorption

ABSTRACT The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy lies with the different detection strategies used by the two groups, which result in very different spectra. This paper seeks to resolve the controversy. We experimentally demonstrate that the use of transmittance detection for sulfur K-edge XAS measurements is highly prone to spectroscopic distortions and that much of the published work on sulfur bacteria is very likely based on distorted data. We also demonstrate that all three detection methods used for X-ray absorption experiments yield essentially identical spectra when the measurements are carried out under conditions where no experimental distortions are expected. Finally, we turn to the original question—the chemical nature of bacterial sulfur. We examine isolated sulfur globules of Allochromatium vinosum and intact cells of a strain of magnetotactic coccus and show that XAS indicates the presence of a chemical form of sulfur resembling S8.

scholarly journals X-ray structure analysis of a metalloprotein with enhanced active-site resolution using in situ x-ray absorption near edge structure spectroscopy

2007 ◽  
Vol 104 (15) ◽  
pp. 6211-6216 ◽  
Author(s):  
A. Arcovito ◽  
M. Benfatto ◽  
M. Cianci ◽  
S. S. Hasnain ◽  
K. Nienhaus ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Active Site ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

In situ analysis of sulfur in the sulfur globules of phototrophic sulfur bacteria by X-ray absorption near edge spectroscopy

1999 ◽  
Vol 1428 (2-3) ◽  
pp. 446-454 ◽  
Author(s):  
Alexander Prange ◽  
Isolde Arzberger ◽  
Claudia Engemann ◽  
Hartwig Modrow ◽  
Oliver Schumann ◽  
...  
Keyword(s):  
In Situ Analysis ◽  
Phototrophic Sulfur Bacteria ◽  
X Ray ◽  
Sulfur Bacteria ◽  
Sulfur Globules ◽  
X Ray Absorption

Neutralization of Calcite in Mineral Aerosols by Acidic Sulfur Species Collected in China and Japan Studied by Ca K-edge X-ray Absorption Near-Edge Structure

2009 ◽  
Vol 43 (17) ◽  
pp. 6535-6540 ◽  
Author(s):  
Yoshio Takahashi ◽  
Takuro Miyoshi ◽  
Masayuki Higashi ◽  
Hikari Kamioka ◽  
Yutaka Kanai
Keyword(s):  
Sulfur Species ◽  
Edge Structure ◽  
X Ray ◽  
Mineral Aerosols ◽  
China And Japan ◽  
X Ray Absorption

scholarly journals High-energy resolution X-ray absorption and emission spectroscopy reveals insight into unique selectivity of La-based nanoparticles for CO2

2015 ◽  
Vol 112 (52) ◽  
pp. 15803-15808 ◽  
Author(s):  
Ofer Hirsch ◽  
Kristina O. Kvashnina ◽  
Li Luo ◽  
Martin J. Süess ◽  
Pieter Glatzel ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
High Energy ◽  
Unit Cell ◽  
High Energy Resolution ◽  
Electron Configuration ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The lanthanum-based materials, due to their layered structure and f-electron configuration, are relevant for electrochemical application. Particularly, La2O2CO3 shows a prominent chemoresistive response to CO2. However, surprisingly less is known about its atomic and electronic structure and electrochemically significant sites and therefore, its structure–functions relationships have yet to be established. Here we determine the position of the different constituents within the unit cell of monoclinic La2O2CO3 and use this information to interpret in situ high-energy resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) and valence-to-core X-ray emission spectroscopy (vtc XES). Compared with La(OH)3 or previously known hexagonal La2O2CO3 structures, La in the monoclinic unit cell has a much lower number of neighboring oxygen atoms, which is manifested in the whiteline broadening in XANES spectra. Such a superior sensitivity to subtle changes is given by HERFD method, which is essential for in situ studying of the interaction with CO2. Here, we study La2O2CO3-based sensors in real operando conditions at 250 °C in the presence of oxygen and water vapors. We identify that the distribution of unoccupied La d-states and occupied O p- and La d-states changes during CO2 chemoresistive sensing of La2O2CO3. The correlation between these spectroscopic findings with electrical resistance measurements leads to a more comprehensive understanding of the selective adsorption at La site and may enable the design of new materials for CO2 electrochemical applications.

scholarly journals Sensitive X-ray Absorption Near Edge Structure Analysis on the Bonding Properties of Au30(SR)18 Nanoclusters

ACS Omega ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 14981-14985 ◽  
Author(s):  
Rui Yang ◽  
David J. Morris ◽  
Tatsuya Higaki ◽  
Matthew J. Ward ◽  
Rongchao Jin ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Edge Structure ◽  
X Ray ◽  
Bonding Properties ◽  
X Ray Absorption

Fluorescence Extended X-Ray Absorption Fine Structure Study on Local Structures of Rare-Earth-Doped InGaGdN

2016 ◽  
Vol 1133 ◽  
pp. 429-433
Author(s):  
Siti Nooraya Mohd Tawil ◽  
Shuichi Emura ◽  
Daivasigamani Krishnamurthy ◽  
Hajime Asahi
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Nearest Neighbor ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Local Structures ◽  
Absorption Fine ◽  
X Ray Absorption

Local structures around gadolinium atoms in rare-earth (RE)-doped InGaGdN thin films were studied by means of fluorescence extended X-ray absorption fine structure (EXAFS) measured at the Gd LIII-edges. The samples were doped with Gd in-situ during growth by plasma-assisted molecular beam epitaxy (PAMBE). Gd LIII-edge EXAFS signal from the GaGdN, GdN and Gd foil were also measured as reference. The X-ray absorption near edge structure (XANES) spectra around Gd LIII absorption edge of InGaGdN samples observed at room temperature indicated the enhancement of intensities with the increase of Gd composition. Further EXAFS analysis inferred that the Gd atoms in InGaN were surrounded by similar atomic shells as in the case of GaGdN with the evidence indicating majority of Gd atoms substituted into Ga sites of InGaGdN. A slight elongation of bond length for the 2nd nearest-neighbor (Gd–Ga) of sample with higher Gd concentration was also observed.

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