Disease relevance of hydroxy-oxo-iron

• Force microscopy has been used to quantitatively measure the infinitesimal forces that characterize interactions between Shewanella oneidensis (a dissimilatory metal-reducing bacterium) and goethite (alpha-FeOOH), both commonly found in Earth near-surface environments [1].
• The adhesion of Pseudomonas aeruginosa to the goethite mineral is investigated using classical molecular simulation [2].
• Chlorine inactivation of Sphingomonas cells attached to goethite particles in drinking water [3].
• Speciation of Pb(II) sorbed by Burkholderia cepacia/goethite composites [4].
• EPS were extracted from both Bacillus subtilis (a gram-positive bacterium) and Pseudomonas aeruginosa (a gram-negative bacterium) and their interaction with the goethite (alpha-FeOOH) surface was studied using attenuated total internal reflection infrared spectroscopy [5].

Psychiatry related information on hydroxy-oxo-iron

• These findings show that the formation of Zn precipitates, similar in structure to brucite, at the pristine kaolinite, goethite, and goethite-coated kaolinite surfaces at near neutral pH and over extended reaction times is an important attenuation mechanism of metal contaminants in the environment [6].

High impact information on hydroxy-oxo-iron

• Based on X-ray diffraction (XRD) analysis, Fe(III) (hydr)oxide produced by oxidation of FeS was shown to be amorphous, while oxidation of Fe(II)sol yielded goethite [7].
• Impacts of goethite particles on UV disinfection of drinking water [8].
• A recent study (D. C. Cooper, F. W. Picardal, A. Schimmelmann, and A. J. Coby, Appl. Environ. Microbiol. 69:3517-3525, 2003) has shown that NO(3)(-) and NO(2)(-) (NO(x)(-)) reduction by Shewanella putrefaciens 200 is inhibited in the presence of goethite [9].
• The electrokinetic potential of goethite at ionic strengths up to 1 mol dm(-3) was determined [10].
• Chemical and biological interactions during nitrate and goethite reduction by Shewanella putrefaciens 200 [11].

Chemical compound and disease context of hydroxy-oxo-iron

• To study the dynamics of Fe and NO(3)(-) biogeochemistry when ferric (hydr)oxides are used as the Fe(III) source, Shewanella putrefaciens 200 was incubated under anoxic conditions in a low-ionic-strength, artificial groundwater medium with various amounts of NO(3)(-) and synthetic, high-surface-area goethite [11].
• The actinomycete Gordonia sp. and the bacterium Pseudomonas fluorescens Pf-5 were grown in liquid media (pH 6.5) with phosphate adsorbed to the Fe-oxide/hydroxide goethite (Goe-P) and with soluble phosphate (0.1 mM or 1.0 mM P as KH2PO4) [12].

Biological context of hydroxy-oxo-iron

• First, the sorption of iron spiked into a slurry of phosphated goethite and the effect of the iron sorption on phosphate uptake kinetics were investigated to determine whether iron would be adsorbed on the phosphated surface and whether it would enhance phosphate adsorption [13].
• Our data indicate that these groups emerge from the EPS mixture to form monodentate complexes with Fe centers on the goethite (alpha-FeOOH) surface, providing an energetically stable bond for further EPS or cell adhesion [5].
• Low crystalline iron hydroxides such as goethite (alpha-FeOOH) and akaganeite (beta-FeOOH) were synthesized, and the selective adsorption of phosphate ions from phosphate-enriched seawater was examined [14].
• At pH 5.8 and room temperature, addition of humic acids (50gl(-1)) increased the rate of hydrolysis tenfold, while addition of kaolinite or goethite (100-250gl(-1)) both decreased the rate considerably [15].
• Enhanced Cu sorption on the montmorillonite/goethite as age increased may be attributed to increased hydroxylation of the mineral surface resulting in the formation of new reactive sites [16].

Associations of hydroxy-oxo-iron with other chemical compounds

• The rate of reduction of p-cyano-N-hydroxylaniline showed a linear relationship against the concentration of surface-associated Fe(II) in hematite, goethite, and lepidocrocite suspensions, while having a relatively low sensitivity toward changes in pH within the near-neutral range in hematite suspensions [17].
• Arsenate sorption on goethite increased in the presence of Zn by 29% and by more than 500% at pH 4 and 7, respectively [18].
• Surface complexation of mellitic acid to goethite: an attenuated total reflection Fourier transform infrared study [19].
• In the presence of 240 microM DFO-B, a strongly depleting effect on Eu(III) adsorption by goethite and boehmite occurred above pH 6 [20].
• Aminomethylphosphonic acid and glyphosate adsorption onto goethite: a comparative study [21].

Gene context of hydroxy-oxo-iron

• 0. The effective particle sizes and zeta-potential of goethite were also determined [22].
• Microscopies (AFM, SEM), XRD and FTIR spectroscopy confirm transformation to both goethite and hematite, with a predominance of hematite [23].
• Macroscopic uptake measurements show that Hg(II) sorbs strongly to fine-grained powders of synthetic goethite (Hg sorption density Gamma=0.39-0.42 micromol/m(2)) and bayerite (Gamma=0.39-0.44 micromol/m(2)), while sorbing more weakly to gamma-alumina (Gamma=0.04-0.13 micromol/m(2)) [24].
• The goethite particles were also characterized by the electron diffraction and high-resolution TEM finding that they were monocrystalline, having the crystalline c axis parallel to the longest particle dimension [25].
• Nanophase iron oxide minerals, such as ferrihydrite and schwertmannite, and nanophase forms of hematite and goethite are formed by both biotic and abiotic processes on Earth. The presence of these minerals on Mars does not indicate biological activity on Mars, but it does raise the possibility [26].

Analytical, diagnostic and therapeutic context of hydroxy-oxo-iron

• The pristine point of zero charge (PZC) of synthetic goethite was found at pH 9.4 as the common intersection point of potentiometric titration curves at different ionic strengths and the isoelectric point (IEP) [10].
• Aging of synthetic goethite at 140 degrees C overnight leads to a composite material in which hematite is detectable by Mössbauer spectroscopy, but X-ray diffraction does not reveal any hematite peaks [10].
• Compared to systems containing only goethite and Zn, microbial Fe(III) reduction in the presence of clay resulted in up to a 50% reduction in Zn immobilization (insoluble in a 2 h 0.5 M HCl extraction) without affecting Fe(II) production [27].
• Further Mossbauer studies of haemosiderin isolated from untreated secondary haemochromatosis patients showed that goethite was the predominant form of iron present, thereby indicating that the presence of this form of ferrihydrite was not wholly attributable to chelation therapy [28].
• From the quantitative evaluation of the induced charge on both components, it is revealed that the degree of the charge adjustment is related to the electrostatic affinity between the PAHA segments and the goethite surface, the electrostatic repulsion between the PAHA segments, and the electrostatic shielding by salt ions [29].

References