Manganese oxidation by manganese peroxidase (MnP) was investigated. Stoichiometric, kinetic, and Mn" binding studies demonstrated that MnP has a single manganese binding site near the heme, and two Mn"' equivalents are formed at the expense of one H202 equivalent. Since each catalytic cycle step is irreversible, the data fit a peroxidase ping-pong mechanism rather than an ordered bi-bi ping...

The white rot fungus Bjerkandera sp. strain BOS55 extensively delignified and bleached oxygen-delignified eucalyptus kraft pulp handsheets. Biologically mediated brightness gains of up to 14 ISO (International Standards Organization units) were obtained, providing high final brightness values of up to 80% ISO. In nitrogen-limited cultures (2.2 mM N), manganese (Mn) greatly improved manganese-de...

Neurotoxicity due to excessive brain manganese (Mn) can occur due to environmental (air pollution, soil, water) and/ or metabolic aberrations (decreased biliary excretion). Manganese is associated with oxidative stress, as well as alterations in neurotransmitter metabolism with concurrent neurobehavioral deficits. Based on the few existing studies that have examined brain regional [Mn], it is l...

The water proton relaxation rate enhancement of Mn(II) bound to bovine serum albumin (BSA) and the association constant for manganese to BSA have already been determined, but such determinations have not been done for human serum albumin (HSA) and other human serum proteins and also for human serum. In this work, NMR T1 values in aqueous solutions of serum proteins and serum were measured versu...

Solvent-based synthesis and characterization of α-Mn(BH4)2 and a new nanoporous polymorph of manganese borohydride, γ-Mn(BH4)2, via a new solvate precursor, Mn(BH4)2·1/2S(CH3)2, is presented. Manganese chloride is reacted with lithium borohydride in a toluene/dimethylsulfide mixture at room temperature, which yields halide and solvent-free manganese borohydride after extraction with dimethylsul...

We examined manganese uptake and translocation in 30-year-old silver fir trees (Abies alba Mill.) showing severe symptoms of needle chlorosis by analyzing both xylem and phloem sap of shoots and an extract of root sap originating from both xylem and phloem elements. Manganese concentrations in shoot xylem and phloem sap were significantly lower in chlorotic trees than in neighboring healthy tre...

The objective of this study was to evaluate the possible effects of manganese (Mn) exposure on variations of cortisol levels in Garra gotyla gotyla. LC50 value of manganese after 96 hours was found to be 3.2mg/l for Garra gotyla gotyla. Three replicates of 10 fishes were subjected to three sub-lethal concentrations of manganese i.e. 0.64mg/l, 1.28mg/l and 1.92mg/l (20%, 40% and 60% respectively...

Ferric uptake regulator (Fur) is a transcriptional regulator that controls the expression of genes involved in the uptake of iron and manganese, as well as vital nutrients, and is essential for intracellular redox cycling. We identified a unique Fur homolog (DR0865) from Deinococcus radiodurans, which is known for its extreme resistance to radiation and oxidants. A dr0865 mutant (Mt-0865) showe...

in the present study, micellar-enhanced ultrafiltration (meuf) was used to remove manganese (mn) (ii) from synthetic wastewater. the effects of different operational conditions on the filtration performance of meuf or the membrane were studied. it was found that the transmembrane pressure has a major influence on the permeate flux and an insignificant effect on the rejection coefficient. the pe...