Optimal Iron Concentration Research Articles

Iron Metabolism and Ferroptosis in Physiological and Pathological Pregnancy.

Iron is a vital element in nearly every living organism. During pregnancy, optimal iron concentration is essential for both maternal health and fetal development. As the barrier between the mother and fetus, placenta plays a pivotal role in mediating and regulating iron transport. Imbalances in iron metabolism correlate with severe adverse pregnancy outcomes. Like most other nutrients, iron exhibits a U-shaped risk curve. Apart from iron deficiency, iron overload is also dangerous since labile iron can generate reactive oxygen species, which leads to oxidative stress and activates ferroptosis. In this review, we summarized the molecular mechanism and regulation signals of placental iron trafficking under physiological conditions. In addition, we revealed the role of iron metabolism and ferroptosis in the view of preeclampsia and gestational diabetes mellitus, which may bring new insight to the pathogenesis and treatment of pregnancy-related diseases.

Enriched Synthesis of Magnetosomes by Expanding the Magnetospirillum magneticum AMB-1 Culture at Optimal Iron Concentration

The Magnetospirillum magneticum AMB-1 species is one of the most widely used magnetotactic bacterial strains for producing magnetosomes under laboratory conditions. Nevertheless, there exist several challenges in expanding and purifying the AMB-1 culture due to the restricted culture conditions. In an attempt to enrich the production of magnetosomes, this study reports the utilization of fermenter culture, which substantially promotes the cell densities at different concentrations of iron content. The experimental results confirmed magnetosomes’ high yield (production rate of 21.1 mg L−1) at the iron content of 0.2 μmol L−1. Moreover, different characterization techniques systematically confirmed the coated lipid membrane, particle size, dispersity, stability, and elemental composition of magnetosomes. Notably, the fermenter culture-based process resulted in highly discrete, dispersed, and stable magnetosomes with an average particle diameter of 50 nm and presented the integrated lipid membrane around the surface. The chemical composition by EDS of magnetosomes represented the presence of various elements, i.e., C, O, Na, P, and Fe, at appropriate proportions. In conclusion, the culture method in our study effectively provides a promising approach towards the culture of the magnetotactic bacterium for the enriched production of magnetosomes.

Blood Serum Minerals - in vivo Mineral Interactions Following Iron Overload

Iron is an essential mineral for the human, animal and plant kingdom, being present in water, soil and air. In the organism, iron is found both as a ferrous ion (Fe2+) and as a ferric ion (Fe3+), being involved in oxidoreduction processes and as part of protein structure or in complexes with anions present in cells and tissues. The optimal iron concentration in the body depends on several characteristics (organism type, age, gender, environmental conditions - especially related to altitude, physiological status and others), but there is a rather small variation between the minimum and maximum required concentration -deficiency or excess having a detrimental effect on the organism. In the present work iron gluconate hydrate (10 mg Fe2+/kg body) has been administered intraperitoneally to rabbits, in two separate injections. We formulated a diet rich in plants with protective role, and at the end of the experiment the level of blood serum sodium, potassium, magnesium, ionic calcium, total calcium, iron and chlorine was measured. The results showed that iron overload led to a significant increase of potassium (55.74%), magnesium (31.57%), iron (20.86%) and calcium (with 19.69% total Ca and 17.19% ionic Ca), while the concentration of sodium and chlorine showed non-significant decreases (sodium decreased by 3.83%, and chlorine decreased by 1.58%). Therefore, the excess iron administered over a short period of time to rabbits influences the metabolism of several minerals such as potassium, magnesium, calcium, iron as well as sodium and chlorine and that is reflected in their blood serum level.

Optimal iron concentrations for growth-associated polyhydroxyalkanoate biosynthesis in the marine photosynthetic purple bacterium Rhodovulum sulfidophilum under photoheterotrophic condition.

Polyhydroxyalkanoates (PHAs) are a group of natural biopolyesters that resemble petroleum-derived plastics in terms of physical properties but are less harmful biologically to the environment and humans. Most of the current PHA producers are heterotrophs, which require expensive feeding materials and thus contribute to the high price of PHAs. Marine photosynthetic bacteria are promising alternative microbial cell factories for cost-effective, carbon neutral and sustainable production of PHAs. In this study, Rhodovulum sulfidophilum, a marine photosynthetic purple nonsulfur bacterium with a high metabolic versatility, was evaluated for cell growth and PHA production under the influence of various media components found in previous studies. We evaluated iron, using ferric citrate, as another essential factor for cell growth and efficient PHA production and confirmed that PHA production in R. sulfidophilum was growth-associated under microaerobic and photoheterotrophic conditions. In fact, a subtle amount of iron (1 to 2 μM) was sufficient to promote rapid cell growth and biomass accumulation, as well as a high PHA volumetric productivity during the logarithmic phase. However, an excess amount of iron did not enhance the growth rate or PHA productivity. Thus, we successfully confirmed that an optimum concentration of iron, an essential nutrient, promotes cell growth in R. sulfidophilum and also enhances PHA utilization.

Blood Serum Minerals - in vivo Mineral Interactions Following Iron Overload

Iron is an essential mineral for the human, animal and plant kingdom, being present in water, soil and air. In the organism, iron is found both as a ferrous ion (Fe2+) and as a ferric ion (Fe3+), being involved in oxidoreduction processes and as part of protein structure or in complexes with anions present in cells and tissues. The optimal iron concentration in the body depends on several characteristics (organism type, age, gender, environmental conditions - especially related to altitude, physiological status and others), but there is a rather small variation between the minimum and maximum required concentration -deficiency or excess having a detrimental effect on the organism. In the present work iron gluconate hydrate (10 mg Fe2+/kg body) has been administered intraperitoneally to rabbits, in two separate injections. We formulated a diet rich in plants with protective role, and at the end of the experiment the level of blood serum sodium, potassium, magnesium, ionic calcium, total calcium, iron and chlorine was measured. The results showed that iron overload led to a significant increase of potassium (55.74%), magnesium (31.57%), iron (20.86%) and calcium (with 19.69% total Ca and 17.19% ionic Ca), while the concentration of sodium and chlorine showed non-significant decreases (sodium decreased by 3.83%, and chlorine decreased by 1.58%). Therefore, the excess iron administered over a short period of time to rabbits influences the metabolism of several minerals such as potassium, magnesium, calcium, iron as well as sodium and chlorine and that is reflected in their blood serum level. Iron is an essential mineral for the human, animal and plant kingdom, being present in water, soil and air. In the organism, iron is found both as a ferrous ion (Fe2+) and as a ferric ion (Fe3+), being involved in oxidoreduction processes and as part of protein structure or in complexes with anions present in cells and tissues. The optimal iron concentration in the body depends on several characteristics (organism type, age, gender, environmental conditions - especially related to altitude, physiological status and others), but there is a rather small variation between the minimum and maximum required concentration -deficiency or excess having a detrimental effect on the organism. In the present work iron gluconate hydrate (10 mg Fe2+/kg body) has been administered intraperitoneally to rabbits, in two separate injections. We formulated a diet rich in plants with protective role, and at the end of the experiment the level of blood serum sodium, potassium, magnesium, ionic calcium, total calcium, iron and chlorine was measured. The results showed that iron overload led to a significant increase of potassium (55.74%), magnesium (31.57%), iron (20.86%) and calcium (with 19.69% total Ca and 17.19% ionic Ca), while the concentration of sodium and chlorine showed non-significant decreases (sodium decreased by 3.83%, and chlorine decreased by 1.58%). Therefore, the excess iron administered over a short period of time to rabbits influences the metabolism of several minerals such as potassium, magnesium, calcium, iron as well as sodium and chlorine and that is reflected in their blood serum level. Keywords: iron overload, blood serum minerals, rabbits Keywords: ron overload, blood serum minerals, rabbits

Regulatory effect of Fe-EDTA on mixotrophic cultivation of Chlorella sp. towards biomass growth and metabolite production

The study examined the effect of varying concentrations of iron in the form of ethylene diamine tetra-acetic acid ferric sodium salt (Fe-EDTA) for cultivation of Chlorella sp. under mixotrophic condition to evaluate biomass growth and metabolites production. The experimental data depicted enhanced biomass production along with lipids, carbohydrates and proteins at an optimal iron concentration (8mg/L). Relatively higher biomass production (5.4g/L; 96h) with simultaneous total chlorophyll (5mg/mL (Chl a/b: 3.7/1.3mg/mL)), carbohydrates (105mg/g) and proteins (593mg/g) was observed with 8 mg/L Fe-EDTA. Total and neutral lipid content of 38% and 15.6% was observed under nutrient deprived conditions. The presence of iron showed distinct influence on the saturated fraction of FAME and increment in oleic acid (omega fatty acids; edible oil). Higher concentrations of Fe-EDTA (10/12mg/L) depicted incremental fraction of oleic acid.

Relationship between serum iron and insulin-like growth factor-I concentrations in 10-day-old calves

Newborn calves are often deficient in iron and progressive reduction in blood iron concentration occurs over the first weeks of life. Some reports indicate the importance of interactions among iron and components of the insulin-like growth factor system. The aim of the study was to determine if there is a relationship between serum iron and insulin-like growth factor-I concentrations in neonatal calves. Blood samples were collected from 16 female Holstein-Friesian calves on day 10 of age. Erythrogram determination and measurements of serum iron, total protein, albumin, total iron binding capacity and serum insulin-like growth factor-I concentrations were performed. Haematological values were measured using an automatic analyzer, biochemical properties were determined spectrophotometrically, insulin-like growth factor-I concentration was measured by radioimmunoassay. Calves were divided into 2 groups according to iron concentrations; the first group of iron-deficient calves (n = 8, Fe < 10 μmol/l) and the second group of calves with optimal iron concentration (n = 8, Fe > 18 μmol/l). Blood indicators in all calves from the first group followed a pattern typically observed in anaemic calves. Insulin-like growth factor-I concentrations were significantly (P < 0.01) lower in the first group compared to the second group. However, insulin-like growth factor-I very strongly correlated with iron in calves from the second group compared to iron-deficient calves (r = 0.624; P < 0.01 and r = 0.478; P > 0.05, respectively). Based on our results, iron seems to have an important relationship to secretion of insulin-like growth factor-I in 10-day-old calves. This is the first report about such relationship in this age group of animals.

Iron Requirements of Infants and Toddlers

Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group because their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of ID anemia (IDA) include low birth weight, high cow's-milk intake, low intake of iron-rich complementary foods, low socioeconomic status, and immigrant status. The aim of this position paper was to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight. There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of ID. There is insufficient evidence to support general iron supplementation of healthy European infants and toddlers of normal birth weight. Formula-fed infants up to 6 months of age should receive iron-fortified infant formula, with an iron content of 4 to 8 mg/L (0.6-1.2 mg(-1) · kg(-1) · day(-1)). Marginally low-birth-weight infants (2000-2500 g) should receive iron supplements of 1-2 mg(-1) · kg(-1) · day(-1). Follow-on formulas should be iron-fortified; however, there is not enough evidence to determine the optimal iron concentration in follow-on formula. From the age of 6 months, all infants and toddlers should receive iron-rich (complementary) foods, including meat products and/or iron-fortified foods. Unmodified cow's milk should not be fed as the main milk drink to infants before the age of 12 months and intake should be limited to <500 mL/day in toddlers. It is important to ensure that this dietary advice reaches high-risk groups such as socioeconomically disadvantaged families and immigrant families.

The Role of Iron Metabolism in Lung Inflammation and Injury.

Iron is required for many vital functions including oxygen transport and energy metabolism. Protective mechanisms maintain optimal iron concentration involving dynamic regulation of the transporters and iron storage proteins. In addition to these systemic regulatory mechanisms, the unique lung environment must provide detoxification from metal-induced oxidative stress and pathogenic infections. This review focuses on the unique role of iron metabolism in lung injury and inflammation.

Characterization of LipL as a Non-heme, Fe(II)-dependent α-Ketoglutarate:UMP Dioxygenase That Generates Uridine-5′-aldehyde during A-90289 Biosynthesis

Fe(II)- and α-ketoglutarate (α-KG)-dependent dioxygenases are a large and diverse superfamily of mononuclear, non-heme enzymes that perform a variety of oxidative transformations typically coupling oxidative decarboxylation of α-KG with hydroxylation of a prime substrate. The biosynthetic gene clusters for several nucleoside antibiotics that contain a modified uridine component, including the lipopeptidyl nucleoside A-90289 from Streptomyces sp. SANK 60405, have recently been reported, revealing a shared open reading frame with sequence similarity to proteins annotated as α-KG:taurine dioxygenases (TauD), a well characterized member of this dioxygenase superfamily. We now provide in vitro data to support the functional assignment of LipL, the putative TauD enzyme from the A-90289 gene cluster, as a non-heme, Fe(II)-dependent α-KG:UMP dioxygenase that produces uridine-5'-aldehyde to initiate the biosynthesis of the modified uridine component of A-90289. The activity of LipL is shown to be dependent on Fe(II), α-KG, and O(2), stimulated by ascorbic acid, and inhibited by several divalent metals. In the absence of the prime substrate UMP, LipL is able to catalyze oxidative decarboxylation of α-KG, although at a significantly reduced rate. The steady-state kinetic parameters using optimized conditions were determined to be K(m)(α-KG) = 7.5 μM, K(m)(UMP) = 14 μM, and k(cat) ≈ 80 min(-1). The discovery of this new activity not only sets the stage to explore the mechanism of LipL and related dioxygenases further but also has critical implications for delineating the biosynthetic pathway of several related nucleoside antibiotics.

Metabolic Response to Iron Deficiency in Saccharomyces cerevisiae

Iron is an essential cofactor for enzymes involved in numerous cellular processes, yet little is known about the impact of iron deficiency on cellular metabolism or iron proteins. Previous studies have focused on changes in transcript and proteins levels in iron-deficient cells, yet these changes may not reflect changes in transport activity or flux through a metabolic pathway. We analyzed the metabolomes and transcriptomes of yeast grown in iron-rich and iron-poor media to determine which biosynthetic processes are altered when iron availability falls. Iron deficiency led to changes in glucose metabolism, amino acid biosynthesis, and lipid biosynthesis that were due to deficiencies in specific iron-dependent enzymes. Iron-sulfur proteins exhibited loss of iron cofactors, yet amino acid synthesis was maintained. Ergosterol and sphingolipid biosynthetic pathways had blocks at points where heme and diiron enzymes function, whereas Ole1, the essential fatty acid desaturase, was resistant to iron depletion. Iron-deficient cells exhibited depletion of most iron enzyme activities, but loss of activity during iron deficiency did not consistently disrupt metabolism. Amino acid homeostasis was robust, but iron deficiency impaired lipid synthesis, altering the properties and functions of cellular membranes.

Metabolismo do ferro: uma revisão sobre os principais mecanismos envolvidos em sua homeostase

Um perfeito sincronismo entre absorcao, utilizacao e estoque de ferro e essencial para a manutencao do equilibrio desse metal no organismo. Alteracoes nesses processos podem levar tanto a deficiencia como ao seu acumulo de ferro, duas situacoes com repercussoes clinicas e laboratoriais importantes para o paciente. Essa revisao aborda os diversos aspectos relacionados com a cinetica do ferro, descrevendo as proteinas e mediadores nela envolvidos. Apresenta, ainda, como e feita a regulacao intracelular e sistemica do ferro que visa a manutencao de uma quantidade otima de ferro para o metabolismo das celulas e, em especial, para uma perfeita hematopoiese.E discutido tambem o importante papel da hepcidina, como regulador da homeostase sistemica. Sera a apresenta da a relacao entre a hepcidina e a resposta de fase aguda, e como as alteracoes na expressao da hepcidina podem contribuir com a fisiopatogenese da anemia de doenca cronica.

Le fer du sol aux produits végétaux

As an essential mineral, iron plays an important role in fundamental biological processes such as photosynthesis, respiration, nitrogen fixation and assimilation, and DNA synthesis. Iron is also a co-factor of many enzymes involved in the synthesis of plant hormones. The latter are involved in many pathways controling plant development or adaptative responses to environmental conditions. Iron reactivity with oxygen leads to its insolubility (responsible for deficiency) and potential toxicity, and complicates iron use by aerobic organisms. If plants lacked an active root system with which to acquire iron from the soil, most would experience iron deficiency and show physiological changes. In contrast, an excess of soluble iron, which can occur in flooded acidic soils, can lead to ferrous iron toxicity due to iron reactivity with reduced forms of oxygen and subsequent free radical production. An optimal iron concentration is thus required for a plant to grow and develop normally. This concentration depends on multiple regulatory mechanisms controlling iron uptake from soil by the roots, as well as iron transport and distribution to the various plant organs. Optimized seed iron content is a major biotechnological challenge identified by the World Health Organization, and it is therefore crucial to understand the underlying mechanisms. Iron delivery to seeds is tightly controlled, and depends on the nature of iron speciation in specific chelates, and their transport.

The role of Fenton’s reaction in aqueous phase pulsed streamer corona reactors

Aqueous phase pulsed streamer corona reactors are currently under development for a number of applications including water and wastewater treatment. Previous research has demonstrated that a high voltage pulsed electrical discharge directly into water leads to the formation of reactive species such as hydrogen peroxide and hydroxyl radicals. Since significant quantities of hydrogen peroxide are produced, the role of Fenton’s reactions in the pulsed corona reactor is analyzed both experimentally and with computer simulations in the present work. Experimental data shows the existence of optimal iron concentrations for the degradation of phenol, and that the formation of hydrogen peroxide by the pulsed corona discharge is dependent upon both the applied electric field and the solution conductivity. A mathematical model based upon mass balances for 31 radical and molecular species in the batch reactor (including 71 chemical reactions) has been developed and sensitivity analysis performed to identify key reactions. This model is used to show the effects of initial reaction conditions (including iron and phenol concentrations) on the degradation of phenol and the formation of reaction intermediate products and by-products. The model results are in qualitative and semi-quantitative agreement with the experimental observations on the effects of initial iron and phenol concentrations on phenol degradation and by-product formation.

Alkane formation during liver microsomal lipid peroxidation

During treatment of animals with the hepatotoxin carbon tetrachloride (CCl 4) short-chain alkanes, e.g. ethane and n-pentane, are formed (1–6). It is now generally accepted that these alkanes originate from the decomposition of lipid hydroperoxides (7). However, studies with model compounds demonstrated that metal ions, e.g. iron, are involved in the breakdown of lipid hydroperoxides to alkanes (8, 9). Because we were interested whether metal ions are also involved in CCl 4-induced lipid peroxidation we studied the effect of ferrous ions on CCl 4-induced alkane formation in rat liver microsomes. This could be important, because lipid peroxides are fairly stable in absence of metal ions (10). First of all we had to develop an in vitro system which gives reproducible measurements of alkanes during microsomal incubation. Furthermore, we had to examine whether these alkanes are indeed formed in hepatic microsomes due to CCl 4. On the other hand, we had to find out what the optimal iron concentration in this system would be.

Role of iron deposition in Sphaerotilus discophorus.

Various physiological aspects of the process of iron deposition in Sphaerotilus discophorus were examined to elucidate its role. The values of iron/protein ratios suggested that a direct relationship existed between the iron concentration of the media and the magnitude of final iron deposition. Saturation of the organism's iron deposition system occurred at a 2.0 mM iron concentration, at a value of 0.6 mg of ferric ion per mg of cell protein. Laboratory data indicated that the strain's very low capacity for iron deposition observed at low external iron concentrations makes it unlikely that it is significant in limiting iron in the natural milieu. Under optimal iron concentrations, however, strain SS1 caused precipitation of iron (adsorbed to cellular material) in broth cultures, which was 10 to 100 times that mediated by some "non-iron" microorganisms. The strain's iron requirement, which was found to be between 0.003 and 0.02 mM, is commensurate with that of other microbes. One hundred micrograms of Mn(II) per ml and possibly 10 mug of either Co(II) or Ni(II) per ml could inhibit iron uptake in the deposition system. Sphaerotilus, when tested for its ability to withstand toxic concentrations of certain trace elements (Co, Cu, Mn, Ni, and Cd), demonstrated no exceptional resistance with respect to several other common microorganisms. Final cell yields were not affected by a varying iron concentration for Sphaerotilus growing under conditions of limiting carbon and nitrogen.