Solutions of tannic (digallic) acid at concentrations of 5 or 50 parts per million reduce dissolved ferric iron to the ferrous state when the pH is less than 4. In solutions with a pH of 4 or more, a black material containing ferric iron and tannic acid is precipitated. In a solution containing 500 parts per million of tannic acid, a ferrous complex forms at a pH of more than 5. This complex is...

The regulation of the expression of the rus operon, proposed to encode an electron transfer chain from the outer to the inner membrane in the obligate acidophilic chemolithoautroph Acidithiobacillus ferrooxidans, has been studied at the RNA and protein levels. As observed by Northern hybridization, real-time PCR and reverse transcription analyses, this operon was more highly expressed in ferrou...

this study deals with bioleaching of the low grade uranium ore of saghand mine in iran using a mixed culture of mesophilic bacteria (acidithiobacillus ferrooxidans, acidithiobacillus thiooxidans and leptospirillum ferrooxidans). experiments were carried out in shaking flask examining the effect of temperature, initial ferrous ion concentration, pulp density and particle size. variations of ph, ...

Iron deficiency and related iron deficiency anaemia (IDA) are the most prevalent nutritional disorders worldwide. The standard treatment involves supplementation with solid or liquid iron supplement preparations, usually based on a ferrous salt such as ferrous sulphate, ferrous fumarate, or ferrous gluconate. In the present study, we compared iron uptake and absorption from various solid and li...

Iron deficiency anaemia represents a major public health problem, particularly in infants, young children, pregnant women, and females with heavy menses. Oral iron supplementation is a cheap, safe, and effective means of increasing haemoglobin levels and restoring iron stores to prevent and correct iron deficiency. Many preparations are available, varying widely in dosage, formulation (quick or...

Nanoparticles of Fe(3)O(4) were synthesized by hydrolysis in an aqueous solution containing ferrous and ferric salts at various ratios with 1,6-hexanediamine as a base. It was found that the ferrous to ferric ratio influences the reaction mechanism for the formation of Fe(3)O(4). When the ratio of ferrous to ferric ions was increased, the formation of large hydroxide particles as a precursor of...

In a hydrothermal preparation of crystalline magnetite (Fe3O4) nanoparticles, the influence of the experimental parameters (initial molar ratio of ferrous/ferric ions, initial concentration of ferrous ions, and heating time), and their interactions, on the particle formation was studied using response surface methodology (RSM), based on a statistical design of experiments (DOE). As indices indi...

Leghemoglobin may be isolated from soybean root nodules as a complex, leghemoglobin a-X of ferric leghemoglobin with a low molecular weight ligand X. That complex dissociates at neutral or alkaline pH and the ligand X may be separated from free leghemoglobin by ultrafiltration. The complex is regenerated by combining ferric leghemoglobin with X. The affinity of ferrous leghemoglobin for X is ve...

1. During pathological states of iron-overload or oxidant stress, low-molecular-mass iron can become available within extracellular fluids. 2. This iron would be converted to the ferrous state were it not for the protective anti-oxidant protein caeruloplasmin. 3. The ferrous-ion-oxidizing activity of caeruloplasmin rapidly converts ferrous ions back to the less reactive ferric state so that the...

Leghemoglobin may be isolated from soybean root nodules as a complex, leghemoglobin a-X of ferric leghemoglobin with a low molecular weight ligand X. That complex dissociates at neutral or alkaline pH and the ligand X may be separated from free leghemoglobin by ultrafiltration. The complex is regenerated by combining ferric leghemoglobin with X. The affinity of ferrous leghemoglobin for X is ve...