concentrations of zn, cu, cr, cd, pb and fe in surface marine sediments of the southern coast of sfax were studied in order to understand current metal contamination at the outlet of a mixed industrial and domestic wastewater effluent discharged into the seawater since 1953. we found that heavy metal concentrations (mg/kg dry weight) in surface marine sediments varied from 42 to 391 for zn, 15 ...

concentrations of zn, cu, cr, cd, pb and fe in surface marine sediments of the southern coast of sfax were studied in order to understand current metal contamination at the outlet of a mixed industrial and domestic wastewater effluent discharged into the seawater since 1953. we found that heavy metal concentrations (mg/kg dry weight) in surface marine sediments varied from 42 to 391 for zn, 15 ...

Limitations on the availability of Fe(III) as an electron acceptor are thought to play an important role in restricting the growth and activity of Geobacter species during bioremediation of contaminated subsurface environments, but the possibility that these organisms might also be limited in the subsurface by the availability of iron for assimilatory purposes was not previously considered beca...

The biogenesis of iron-sulfur [Fe-S] clusters requires the coordinated delivery of both iron and sulfide. Sulfide is provided by cysteine desulfurases that use L-cysteine as sulfur source. So far, the physiological iron donor has not been clearly identified. CyaY, the bacterial ortholog of frataxin, an iron binding protein thought to be involved in iron-sulfur cluster formation in eukaryotes, i...

Formation of Fe(II)-As(III) solids is suspected to limit dissolved As concentrations in anaerobic environments. Iron(II) precipitates enriched in As(III) have been observed after microbial reduction of As(V)-loaded lepidocrocite (γ-FeOOH) and symplesite (Fe(II)(As(V)O)]·8HO) and upon abiotic reaction of Fe(II) with As(III). However, the conditions favorable for Fe(II)-As(III) precipitation and ...

In this study, we examined hydroxyl radical ( OH) formation with respect to photoreactivity of colored dissolved organic matter (CDOM), the Fenton reaction, and photoflocculation using leachate from decaying wood. The relationship between OH photoproduction rate and leachate optical properties (UV-visible absorption and fluorescence excitationemission matrices (EEMS)) was studied during irradia...

Bacteria use three distinct systems for iron-sulfur (Fe/S) cluster biogenesis: the ISC, SUF, and NIF machineries. The ISC and SUF systems are widely distributed, and many bacteria possess both of them. In Escherichia coli, ISC is the major and constitutive system, whereas SUF is induced under iron starvation and/or oxidative stress. Genomic analysis of the Fe/S cluster biosynthesis genes in Bac...

Force enhancement (FE) associated with lengthening is a well-accepted phenomenon of active skeletal muscle, but the underlying mechanism(s) remain unknown. Similar to force depression (FD) following active shortening, the mechanism of FE may be attributed, at least in part, to cross-bridge kinetics. To examine this relationship, a post hoc analysis was performed on the transient force relaxatio...