The bacterioferritin (BFR) of Escherichia coli takes up iron in the ferrous form and stores it within its central cavity as a hydrated ferric oxide mineral. The mechanism by which oxidation of iron (II) occurs in BFR is largely unknown, but previous studies indicated that there is ferroxidase activity associated with a site capable of forming a dinuclear-iron centre within each subunit [Le Brun...

Margalith, P. (Syracuse University, Syracuse, N.Y.), Marvin Silver, and D. G. Lundgren. Sulfur oxidation by the iron bacterium Ferrobacillus ferrooxidans. J. Bacteriol. 92:1706-1709. 1966.-Sulfur and iron oxidation has been studied manometrically by use of Ferrobacillus ferrooxidans grown on either elemental sulfur or ferrous iron as the primary energy source. The iron-oxidizing enzyme was show...

Oxidation of low-density lipoprotein (LDL) may play an important role in atherosclerosis. We studied the effects of bicarbonate/CO2 and phosphate buffer systems on metal ion-catalyzed oxidation of LDL to malondialdehyde (MDA) and to protein carbonyl and MetO derivatives. Our results revealed that LDL oxidation in mixtures containing free iron or heme derivatives was much greater in bicarbonate/...

The aim of the present study was to investigate whether the in vitro pro-oxidant effect of ascorbic acid towards thiol groups could be mediated by free radicals formed during its auto-oxidation and/or by a direct oxidation of -SH groups by its oxidized form (dehydroascorbic acid). This hypothesis was examined by measuring the rate of AA (ascorbic acid) oxidation in MOPS (3-morpholinepropanesulf...

A controlled and scalable multistep purification method has been developed to remove iron impurity and nonnanotube carbon materials from raw single-walled carbon nanotubes (SWNTs) produced in the HiPco (high-pressure CO) process. In this study, iron nanoparticles, coated by carbon, are exposed and oxidized by multiple step oxidation at increasing temperatures. To avoid catalytic oxidation by ir...

The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs). In At...

Iron-reducing and oxidizing microorganisms gain energy through reduction or oxidation of iron, and by doing so play an important role in the geochemical cycling of iron. This study was undertaken to investigate mineral transformations associated with microbial reduction of Fe3+ and oxidation of Fe2+ in solid minerals. A fluid sample from the 2450 m depth of the Chinese Continental Scientific Dr...

The origin of previously observed variations in stoichiometry of iron oxidation during the oxidative deposition of iron in ferritin has been poorly understood. Knowledge of the stoichiometry of Fe(II) oxidation by O2 is essential to establishing the mechanism of iron core formation. In the present work, the amount of Fe(II) oxidized was measured by Mössbauer spectrometry and the O2 consumed by ...

a-Ketoglutarate-dependent enzymes catalyze many important biological oxidation/oxygenation reactions. Iron(IV)–oxo intermediates have been established as key oxidants in these oxidation reactions. While most reported model iron(II)–a-keto acid complexes exhibit stoichiometric reactivity, selective oxidation of substrates with dioxygen catalyzed by biomimetic iron(II)–a-keto acid complexes remai...

Many of the landfills may contain xenobiotic compounds including monoaromatic hydrocarbons and halogenated hydrocarbons, which are well documented to have negative effects in the aquatic environment and are resistant to biodegradation. In this research, landfill leachate was treated by combined advanced oxidation and suspended fiber biofiltration. Advanced oxidation destructed xenobiotics in th...