The covalent modifications of sulfhydryl groups (-SH) may occur through oxidation to mixed disulfides (S-thiolation), S-nitrosylation, as well as persulfide and trisulfide formation. The latter possibilities of -SH group modification connected with compounds containing sulfur called sulfane sulfur are described in this paper. Sulfane sulfur compounds contain a labile, highly reactive sulfur ato...

The oxidation of ferrous iron and elemental sulfur by Thiobacillus ferrooxidans that was absorbed and unabsorbed onto the surface of sulfur prills was studied. Unadsorbed sulfur-grown cells oxidized ferrous iron at a rate that was 3 to 7 times slower than that of ferrous iron-grown cells, but sulfur-grown cells were able to reach the oxidation rate of the ferrous iron-adapted cells after only 1...

The green sulfur bacterium Chlorobaculum tepidum is proposed to oxidize sulfide and elemental sulfur via sulfite as an obligate intermediate. The sulfite pool is predicted to be contained in the cytoplasm and be oxidized by the concerted action of ApsBA, which directly oxidizes sulfite, and QmoABC, which transfers electrons from ApsBA to the quinone pool. Like other green sulfur bacteria, C. te...

*Correspondence: Sheng S. Zhang, Electrochemistry Branch, RDRL-SED-C, Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, MD 20783-1197, USA e-mail: [email protected]; [email protected] Liquid electrolyte lithium/sulfur (Li/S) batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and...

The purple photosynthetic sulfur bacterium, Chromatium, will grow only in the light and under anaerobic conditions. This organism can grow on an inorganic medium utilizing CO2 as the sole carbon source in the presence of reduced inorganic sulfur compounds. Some reduced carbon compounds can be utilized for the growth of this organism but only in the light and under anaerobic conditions. In this ...

Functionalization of silica surfaces using organo-silanes is highly sensitive to reaction conditions. Silica-coated nanoparticles were functionalized with propyl-sulfonic acid groups (PS) under different synthesis conditions including, various solvents (Ethanol, methanol, acetonitrile, and toluene), water content in the reaction media (0% to 50%), 3-mercaptopropyl-trimethoxysilane concentration...

Sulfide:quinone oxidoreductase (SQR) was purified from membrane of acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans NASF-1 cells grown on sulfur medium. It was composed of a single polypeptide with an apparent molecular mass of 47 kDa. The apparent K(m) values for sulfide and ubiquinone were 42 and 14 muM respectively. The apparent optimum pH for the SQR activity was about...

Sulfur speciation was determined in real time in salt marsh microbial mats, subtidal sediments and hydrothermal vent diffuse flow waters using solid state gold-amalgam voltammetric microelectrodes. Chemical species were measured in situ without any sample manipulation or processing. The partially oxidized sulfur species detected were polysulfides, thiosulfate, elemental sulfur and tetrathionate...

Elemental sulfur cathodes for lithium/sulfur cells are still in the stage of intensive research due to their unsatisfactory capacity retention and cyclability. The undesired capacity degradation upon cycling originates from gradual diffusion of lithium polysulfides out of the cathode region. To prevent losses of certain intermediate soluble species and extend lifespan of cells, the effective en...

The nutrient elements uptake in many of soils, is a problem because of high pH and plenty of calcium ions in them. Some of these elements are phosphorus and microelements. It is possible to increase absorption of these nutrient elements by addition of sulfur in soil and biological oxidation. The rate of this reaction is very slow and Thiobacillus bacteria are the most important oxidators of sul...