Most of the dissolved iron (Fe) in seawater is complexed by organic ligands. One key issue in understanding Fe limitation in the sea is the bioavailability of different forms of Fe to marine phytoplankton. We measured Fe uptake by the coastal diatom Thalassiosira pseudonana and the cyanobacterium Synechococcus sp., using model ligands desferrioxamine B (DFB) and ferrichrome (FC), humic acids (H...

Twenty-four organic Fe sources were evaluated by polarographic analysis and via solubility in buffers (pH 5 and 2) and deionized water. Organic Fe sources included 6 Fe-Met complexes (Fe-Met), 10 Fe-Gly complexes, 1 Fe-Lys complex, 4 Fe proteinates, and 3 Fe-AA complexes (Fe-AA). Sources varied considerably in chemical characteristics. Chelation strengths (quotient of formation [Q] values) rang...

this research aimed to study on effect of foliar spraying with zinc (as zinc sulphate), nitrogen (as urea) and iron (as sulphate and chelated fe) on growth parameters, quality of fruit, flower characteristics, chemical constituents and nutrients content of leaves on grapevine. applied nutrients were zinc sulphate (zn) of 0.0 and 1.5gl-1 and urea (n) at 0.0 and 5 gl-1 and fe (1) control (low fe)...

abstract a hydroponics experiment was conducted to compare effect of fe-deficiency on concentration, uptake, translocation of fe, zn, mn in some plants. a completely randomized block design in triplicates was conducted in research greenhouse. seven plants with different fe-efficiency contained two bread wheat genotypes (triticum aestivium l. cvs. backcross roshan and qods), triticale (x. tritic...

We employ spin-polarized periodic density functional theory (DFT) to examine carbon atom adsorption on, absorption in, and diffusion into Fe(110) and Fe(100). We find that carbon atoms bind strongly with Fe surfaces and prefer high coordination sites. The carbon atom is predicted to adsorb on the long-bridge site on Fe(110) and the fourfold hollow site on Fe(100). Due to the very short distance...

The title compound, [Fe(2)(C(14)H(10)NS(2))(2)(CO)(6)], was synthesized as a structural and biochemical model for the active site of [FeFe]-hydrogenase. The bond lengths (Fe-Fe, Fe-S and Fe-C) and angles (C-Fe-Fe and Fe-S-Fe) are within expected ranges. The S⋯S distance [2.9069 (12) Å] and the dihedral angle between two Fe-S-Fe planes [78.5 (3)°] of the butterfly-shaped Fe(2)S(2) core are enlar...

Reduction of Fe(3+) to Fe(2+) is a prerequisite for Fe uptake by tomato roots. Ferric chelate reductase activity in plasma membranes (PM) isolated from roots of both iron-sufficient (+Fe) and iron-deficient (-Fe) tomatoes (Lycopersicon esculentum Mill.) was measured as NADH-dependent ferric citrate reductase and exhibited simple Michaelis-Menten kinetics for the substrates, NADH and Fe(3+)(citr...

The structure of the iron sites of nitrogenase in dithionite-reduced and thionine-oxidized forms of the Mo-Fe and V-Fe proteins has been investigated using Fe K-edge X-ray absorption spectroscopy. For the dithionite-reduced Azotobacter uinelandii Mo-Fe protein, the dominant EXAFS Fourier transform peaks are assigned to F e 4 and Fe-Fe interactions at -2.32 and 2.64 A, as expected for F e S clus...