During the enzymatic cycle of the cytochromes P450, dioxygen binds to the ferrous haemprotein when the resting ferric haemprotein has undergone a one-electron oxidation after substrate binding. A further one-electron reduction generates an intermediate that is isoelectronic with a peroxide dianion coordinated to a ferric iron. Heterolytic cleavage of the omicron--omicron bond generates water an...

The 'iron bacteria' are a collection of morphologically and phylogenetically heterogeneous prokaryotes. They include some of the first micro-organisms to be observed and described, and continue to be the subject of a considerable body of fundamental and applied microbiological research. While species of iron-oxidizing bacteria can be found in many different phyla, most are affiliated with the P...

Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe(2+) or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe(2+) oxidization and H⁺ production were evaluated. Second,...

The hydrothermal sediments of Guaymas Basin, an active spreading center in the Gulf of California (Mexico), are rich in porewater methane, short-chain alkanes, sulfate and sulfide, and provide a model system to explore habitat preferences of microorganisms, including sulfate-dependent, methane- and short chain alkane-oxidizing microbial communities. In this study, hot sediments (above 60°C) cov...

to assess the microbiological status of a biofiltration system used to treat borehole water, filtermatrix samples were analyzed after staining for the presence of active biofilms using confocal laser scanningmicroscopy (clsm). clsm revealed the presence of biofilms on the filter matrix with actively metabolizingmicrobial cells present. thereafter, heterotrophs,manganese oxidizing bacteria (mob)...

Introduction: Human’s body and other creatures fight with destructive factors, as well as other factors that threaten human health and life. There is an antioxidant biological system in living organisms to face oxidizing compounds. In this immune system, compounds are found that react directly with oxidizing agents and make them neutral. The variety of compounds are included co...

Most proteins produced in the endoplasmic reticulum (ER) of eukaryotic cells fold via disulfide formation (oxidative folding). Oxidative folding is catalyzed by protein disulfide isomerase (PDI) and PDI-related ER protein thiol disulfide oxidoreductases (ER oxidoreductases). In yeast and mammals, ER oxidoreductin-1s (Ero1s) supply oxidizing equivalent to the active centers of PDI. In this study...

Active oxygen species are produced as a consequence of normal aerobic metabolism. Of these, free radicals are usually metabolized or inactivated in vivo by a team of antioxidants. Individual members are a trained team fighting antioxidants to prevent the generation of ROS, destroy or oxidizing potential of capture. In terms of physiological oxidative stress, induced tissue attack is minimal. A ...

Studying catalysts in situ is of high interest for understanding their surface structure and electronic states in operation. Herein, we present a study of epitaxial manganite perovskite thin films (Pr1−xCaxMnO3) active for the oxygen evolution reaction (OER) from electro-catalytic water splitting. X-ray absorption near-edge spectroscopy (XANES) at the Mn Land O K-edges, as well as X-ray photoem...