Iron or sulfur respiration-an adaptive choice determining the fitness of a natronophilic bacterium in geochemically contrasting environments.

Haloalkaliphilic microorganisms are double extremophiles functioning optimally at high salinity and pH. Their typical habitats are soda lakes, geologically ancient yet widespread ecosystems supposed to harbor relict microbial communities. We compared metabolic features and their determinants in two strains of the natronophilic species , the only cultured representative of the class "" ().

Study of Phase Transformations and Hyperfine Interactions in FeO and FeO@Au Nanoparticles.

The paper presents the results of a study of iron oxide nanoparticles obtained by chemical coprecipitation, coated (FeO@Au) and not coated (FeO) with gold, which were subjected to thermal annealing. To characterize the nanoparticles under study, scanning and transmission electron microscopy, X-ray diffraction, and Mössbauer spectroscopy on Fe nuclei were used, the combination of which made it possible to establish a sequence of phase transformations, changes in morphological and structural characteristics, as well as parameters of hyperfine interactions. During the studies, it was found that thermal annealing of nanoparticles leads to phase transformation processes in the following sequence: nonstoichiometric magnetite (FeO) → maghemite (γ-FeO) → hematite (α-FeO), followed by structural ordering and coarsening of nanoparticles.

Size-Dependent Structural, Magnetic and Magnetothermal Properties of YFeO Fine Particles Obtained by SCS.

Iron-containing oxides are the most important functional substance class and find a tremendous variety of applications. An attractive modern application is their use in biomedical technologies as components in systems for imaging, drug delivery, magnetically mediated hyperthermia, etc. In this paper, we report the results of the experimental investigation of submicron YFeO garnet particles obtained in different sizes by solution combustion synthesis (SCS) using glycine organic fuel to discuss the interdependence of peculiarities of the crystal and magnetic structure and size's influence on its functional magnetothermal performance.

Peculiar Spin-Crossover Behavior in the 2D Polymer K[Fe(5Cl-thsa)].

A potassium salt of the NSO-coordination Fe(III) anion K[Fe(5Cl-thsa)] () (5Cl-thsa - 5-chlorosalicylaldehyde thiosemicarbazone) is synthesized and characterized structurally and magnetically over a wide temperature range. Two polymorphs of salt characterized by the common 2D polymer nature and assigned to the same orthorhombic space group have been identified. The molecular structure of the minor polymorph of was solved and refined at 100, 250, and 300 K is shown to correspond to the LS configuration.

Mössbauer, Nuclear Forward Scattering, and Raman Spectroscopic Approaches in the Investigation of Bioinduced Transformations of Mixed-Valence Antimony Oxide.

Mössbauer spectroscopy, nuclear forward scattering, and Raman spectroscopy were applied to study redox transformations of the synthesized mixed-valence (III/V) antimony oxide. The transformations were induced by a culture of a hyperthermophilic archaeon of the genus . The applied methods allowed us to reveal the minor decrease of ca.

Study of Magnetic Properties of FeNi Nanostructures Using the Mössbauer Spectroscopy Method.

Hyperfine interactions of Fe nuclei in FeNi nanostructures synthesized in polymer ion-track membranes were studied by Mössbauer spectroscopy. The main part of obtained nanostructures was FeNi nanotubes with bcc structure for 0 ≤ x ≤ 40, and with fcc structure for 50 ≤ x ≤ 90. The length, outside diameter and wall thickness of nanotubes were 12 μm, 400 ± 10 nm and 120 ± 5 nm respectively.

Genomic Insights Into Energy Metabolism of Coupling Hydrogenogenic CO Oxidation With the Reduction of Fe(III) Minerals.

The genus forms a deeply branching family in the class and is currently represented by three physiologically diverse species of thermophilic prokaryotes. The type strain of the type species, 41, is an obligate chemolithoautotroph growing exclusively by hydrogenogenic CO oxidation. Another strain, isolated from a hot spring at Uzon caldera, Kamchatka in the course of this work, is capable of coupling carboxydotrophy and dissimilatory reduction of Fe(III) from oxic and phyllosilicate minerals.

Towards a revisitation of vesuvianite-group nomenclature: the crystal structure of Ti-rich vesuvianite from Alchuri, Shigar Valley, Pakistan.

Vesuvianite containing 5.85 wt% TiO from an Alpine-cleft-type assemblage outcropped near Alchuri, Shigar Valley, Northern Areas, Pakistan, has been investigated by means of electron microprobe analyses, gas-chromatographic analysis of HO, X-ray powder diffraction, single-crystal X-ray structure refinement, Al NMR, Fe Mössbauer spectroscopy, IR spectroscopy and optical measurements. Tetragonal unit-cell parameters are: a = 15.