Diverse bacteria are known to oxidize millimolar concentrations of ferrous iron [Fe(II)] under anaerobic conditions, both phototrophically and chemotrophically. Yet whether they can do this under conditions that are relevant to natural systems is understood less well. In this study, we tested how light, Fe(II) speciation, pH, and salinity affected the rate of Fe(II) oxidation by Rhodobacter cap...

The distribution of neutrophilic microbial iron oxidation is mainly determined by local gradients of oxygen, light, nitrate and ferrous iron. In the anoxic top part of littoral freshwater lake sediment, nitrate-reducing and phototrophic Fe(II)-oxidizers compete for the same e(-) donor; reduced iron. It is not yet understood how these microbes co-exist in the sediment and what role they play in ...

Large chiral triangular macrocycles having three salen ligand sites were obtained by cyclocondensation of trans-1,2-diaminocyclohexane with linearly connected bis-salicylaldehydes. Structures of the ligands and their titanium(IV) or zinc(II) complexes have been characterized by means of spectroscopic (CD) and computational (DFT) methods.

this paper investigates the removal of iron and zinc from aqueous solution with dairy wastewaterin three different biomasses such as lactobacillus delbrueckii ssp bulgaricus (lb-12), streptococcus thermophillus(stm-7) and a combination of both this bacteria culture (yc-380) and the optimization of removal efficiencyusing minitab program. a full 23 factorial design of experiments was applied to ...

Interfacial electron transfer has been shown to occur between sorbed Fe(II) and structural Fe(III) in Fe oxides, but it is unknown whether a similar reaction occurs between sorbed Fe(II) and Fe(III)-bearing clay minerals. Here, we used the isotopic specificity of (57)Fe Mössbauer spectroscopy to demonstrate electron transfer between sorbed Fe(II) and structural Fe(III) in an Fe-bearing smectite...

Crystalline peptide Ni(ii)-macrocycles (BF4(-) salt) exhibited moderate CO2 gas adsorption (ca. 6-7 CO2 molecules per macrocycle) into very narrow cavities (narrowest part <2 Å), accompanied by the expansion of the cavities. The BF4(-) salt demonstrated selective uptake of CO2 gas in preference to CH4 and N2 gases.

Anoxygenic phototrophic Fe(II) oxidation is usually considered to be a lithoautotrophic metabolism that contributes to primary production in Fe-based ecosystems. In this study, we employed Rhodobacter capsulatus SB1003 as a model organism to test the hypothesis that phototrophic Fe(II) oxidation can be coupled to organic carbon acquisition. R. capsulatus SB1003 oxidized Fe(II) under anoxic cond...

Nitrate-reducing Fe(II)-oxidizing microorganisms were described for the first time ca. 20 years ago. Most pure cultures of nitrate-reducing Fe(II) oxidizers can oxidize Fe(II) only under mixotrophic conditions, i.e., when an organic cosubstrate is provided. A small number of nitrate-reducing Fe(II)-oxidizing cultures have been proposed to grow autotrophically, but unambiguous evidence for autot...

We studied the effects of humic substances (HS) on the sorption of Fe(II) onto Al-oxide and clay sorbents at pH 7.5 with a combination of batch kinetic experiments and synchrotron Fe K-edge EXAFS analyses. Fe(II) sorption was monitored over the course of 4 months in anoxic clay and Al-oxide suspensions amended with variable HS types (humic acid, HA; or fulvic acid, FA) and levels (0, 1, and 4 w...

Two imine-based shape-persistent macrocycles containing triphenylene building blocks, along with their noncyclic model compounds, have been synthesized. Their stable conformations are predicted by quantum mechanical calculations and confirmed by 2D NOESY NMR measurements. Compared to the noncyclic model compounds, the macrocycles (3 and 6) show a higher propensity for solution self-assembly due...