Addition Of Manganese Ions Research Articles

Statistical and network analyses reveal mechanisms for the enhancement of macrophage immunity by manganese in Mycobacterium tuberculosis infection

Tuberculosis is a significant infectious disease that poses a serious risk to human health. Our previous research has indicated that manganese ions reduce the bacterial load of Mycobacterium tuberculosis in macrophages, but the exact immune defense mechanism remains unknown. Several critical proteins and pathways involved in the host's immune response during this process are still unidentified. Our research aims to identify these proteins and pathways and provide a rationale for the use of manganese ions in the adjuvant treatment of tuberculosis. We downloaded GSE211666 data from the GEO database and selected the RM (Post-infection manganese ion treatment group) and Ra (single-infection group) groups for comparison and analysis to identify differential genes. These differential genes were then enriched and analyzed using STRING, Cytoscape, and NDEx tools to identify the two most relevant pathways of the “Host Response Signature Network.” After conducting an in-depth analysis of these two pathways, we found that manganese ions mainly mediate (1) the interferon -gamma (IFN-γ) and its receptor IFNGR and the downstream JAK-STAT pathway and (2) the NFκB pathway to enhance macrophage response to interferon, autophagy, polarization, and cytokine release. Using qPCR experiments, we verified the increased expression of CXCL10, MHCII, IFNγ, CSF2, and IL12, all of which are cytokines that play a key role in resistance to Mycobacterium tuberculosis infection, suggesting that macrophages enter a state of pro-inflammatory and activation after the addition of manganese ions, which enhances their immunosuppressive effect against Mycobacterium tuberculosis. We conclude that our study provides evidence of manganese ion's ability to treat tuberculosis adjuvantly.

Activity of photosystem II in spring barley leaves under the action of manganese ions

The influence of manganese ions (30, 60 and 90 mg/l) on the functioning of the photosystem II (PSII) in leaves was assessed on plants of six spring barley cultivars (Belgorodsky 100, st.). The plants were grown on a complete Knop medium without (control) and with the addition of manganese ions (experiment) under natural light conditions. On 14-day-old leaves, parameters of chlorophyll's rapid fluorescence were recorded using a Fluor Pen FP 110/S fluorometer. The sensitivity of the different structural parts of PSII was found to vary depending on the concentration of Mn ions and the genotype used. Thus, absorbed energy flows increased in the cv. Boyarin at 30 and 60 mg/l Mn (by 7.9 and 14.1 %), in cv. Farmer at 60 and 90 mg/l (by 15.8 and 16.1 %), but decreased in cv. Dobryak at 30 and 90 mg/l (by 9.7 and 9.0 %), Farmer at 30 mg/l (by 15.8 %) and Bionic at 60 and 90 mg/l (by 8.0 and 6.8 %). The flow of energy stored in primary photochemical reactions in the cv. Bionic increased at 30 mg/l of manganese (by 6.3 %), but decreased at 60 (by 6.8 %) and 90 mg/l (by 5.3 %); increased in the cv. Boyarin at 30 mg/l of Mn (by 6.4 %), but decreased in the cv. Forward (by 11.7 %). Electronic transport leading to CO2 fixation increased in cv. Farmer at all Mn concentrations (by 8.1...12.6 %), and in cv. Bionic it increased at 30 mg/l (by 7.2 %), but decreased at 90 mg/l (by 7.4 %). The electron flux leading to the oxidation of the finile acceptor of PSI in the studied cultivars did not change under the influence of the stressor. However, the integral parameters of PSII activity (PIABS and PIABS_total indices) under stressful conditions were determined by the plant genotype. This indicates, firstly, the need for targeted selection (to a specific level of the stress factor); secondly, on the possibility of pyramidation of the integral level of resistance to the stressor by selecting parents who differ in the level of change in individual functional reactions of photosynthesis.

Interaction of Manganese Ions with Scheelite Surfaces and Its Effect on Collector Adsorption and Flotation

Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO4. Improving the surface properties of scheelite to increase its adsorption of the collector for flotation separation is the focus of our current research. In this paper, the effects of manganese ions on scheelite flotation in benzohydroxamic acid (BHA) system were studied by micro-flotation tests, adsorption tests, fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of Mn2+ was found to improve the recovery of scheelite. The addition of Mn2+ greatly improved the recovery of scheelite. Infrared spectroscopy, adsorption tests, zeta potential measurements and XPS analysis all confirmed that BHA had a higher adsorption capacity and a stronger bond to the surface of scheelite after the addition of manganese ions, increasing the floatability of scheelite particles. Therefore, Mn2+ shows great potential for the improvement of the flotation index of scheelite in a system with BHA.

Structural and dielectric properties of ceramic and thin film multiferroics based on Ba0.5Sr0.5TiO3

This paper presents the results of a study of the structural and dielectric properties of barium-strontium titanate (Ba0.5Sr0.5TiO3) with a high concentration of doped manganese ions. It was found that upon the addition of manganese ions, the phase transition point shifts toward lower temperatures. A graph of the dependence of the ceramic lattice parameters on the concentration of manganese ions is presented. It is shown that with an increase in the sintering temperature of ceramics, the dielectric constant of the samples increases.

Study on discharge voltage and discharge capacity of LiFe1−xMnxPO4 with high Mn content

Rod-like LiFe1−xMnxPO4/C cathode with particle size of about 300–500 nm was fabricated successfully via simple hydrothermal method. By means of adjusting the manganese content of LiFe1−xMnxPO4, the electrochemical property was studied to clarify the effect of manganese content. LiFe1−xMnxPO4/C sample with x = 0.70 showed the superior specific discharge capacity of 153.1 mAh g−1 at a rate of 0.1 C, and the electrochemical mechanism analyzed by electrochemical impedance spectra demonstrated that the LiFe0.30Mn0.70PO4/C exhibited the smallest charge transfer impedance and the largest lithium-ion diffusion coefficient. With the increase of manganese content, the reduction of discharge capacity is attributed to the linear decrease of Mn2+/Mn3+ reduction reaction. When x = 0.80, the two discharge platforms located at 3.5 and 3.9 V, respectively, reach a maximum, which result from the reduction electromotive force of Fe2+/Fe3+ affected by the addition of manganese ions since the discharge platform of LiMnPO4 is higher than that of LiFePO4.

Obtaining Mn-Co Alloys in AISI 430 Steel from Lithium-Ion Battery Recycling: Application in SOFC Interconnectors

The recycling of exhausted lithium-ion batteries from mobile phones originate five solutions with different Co and Mn proportions that were used as electrolytic solutions to obtain Mn-Co spinel coatings on the surface of AISI430 stainless steel. The coatings are intended to contain chromium volatility in the working conditions of Solid Oxide Fuel Cells (SOFC) metallic interconnectors. Potentiostatic electrodeposition was the technique used to obtain Mn-Co coatings from low concentration electrolytes at pH = 3.0 and potential applied −1.3 V. Charge efficiency data were used for sample optimization. Three optimized samples were subjected to oxidation heat treatment at 800 °C for 300 h and then characterized by XRD, SEM and EDS. The results showed that the addition of manganese ions instead of cobalt ions in the electrolytic bath produces more stable and well-distributed deposits as the ratio of the two ions becomes equal in the electrolytic bath. Thin, homogeneous and stable spinel coatings (Mn, Co)3O4 2.8 μm and 3.9 μm thick were able to block chromium volatility when exposed to SOFC operating temperature.

Influence of Manganese Ions on the Electrodeposition Process of Lead Dioxide in Lead Nitrate Solution

The influence of manganese ions on the electrodeposition process of lead dioxide on the glassy carbon electrode (GCE) in the lead nitrate solution was investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The results show that the electrodeposition process of lead dioxide was inhibited by the addition of manganese ions. However, the nucleation model is not influenced by the addition of manganese ions and the electrodeposition process still fits the instantaneous nucleation model with three-dimensional growth according to Scharifker—Hills’ model.

Multiferroic Aurivillius-type Bi6Fe2\u2212xMnxTi3O18 (0\xa0\u2264\xa0x\xa0\u2264\xa01.5) ceramics with negative dielectric constant

Aurivillius-type ceramics Bi6Fe2−xMnxTi3O18x = 0, 0.3, 0.9, 1.5 were obtained by a solid-state reaction method using high-purity TiO2, Bi2O3, Fe2O3 and Mn2O3 powders. The milled powder was calcined at 1113 K for 4 h. After calcination, the powder was milled again than pressed into pellets and sintered at 1213 K for 4 h. It was detected that the addition of manganese ions to the multiferroic five-layer Aurivillius-type structure affects the size of the grains. It was found that, the certain amount of manganese ions causes that the polarization of the material doped by them, have the direction opposite to the direction of the applied electric field. The doped material behaves like dia-electric material. The presented research complements the research concerning the Aurivillius ceramics doped with manganese. An attempt was made to explain the reasons for the negative values of dielectric constant and dielectric loss, that occur in manganese-doped five-layer Aurivillius type ceramics and which have not been described in the literature so far.

Molecular Recognition of Metal Ions by Bacterial Ribonuclease P

Ribonuclease P (RNase P) catalyzes the 5′ end maturation of precursor‐tRNAs (pre‐tRNAs). Bacterial RNase P is composed of one catalytic RNA subunit and one protein subunit important for molecular recognition. Like many other large ribozymes, divalent metal ions both stabilize the folded structure and enhance the catalytic activity of RNase P. Identification of the RNA moieties involved in metal‐binding and discerning the function of these interactions is an important outstanding question in RNA catalysis field. The recently solved crystal structure of bacterial RNase P [1] proposed that a catalytic metal coordinates the carbonyl oxygen of the bulged uracil in the conserved helix P4. To examine this proposal, we substituted the bulged uridine in the P4 helix of circularly permuted Bacillus subtilis RNase P with 4‐thio‐uridine which substitutes a sulfur atom for the carbonyl oxygen at position 4 on the base. This substitution decreases the single‐turnover cleavage rate by 30‐fold at pH 5.5 but has little effect on the K1/2 for activation by Mg(II) in the presence of Ca(II). Furthermore, the activity of the 4‐thio‐U mutant is not rescued by the addition of manganese ions. These data argue against the formation of an inner sphere contact between the carbonyl oxygen in the bulged uridine of P4 and a catalytic metal ion in RNase P. (This work is supported by funding from NIH (GM 55387)).

Influence of manganese on iron oxyhydroxides and oxides formed in aqueous solution

Structural analysis techniques such as X-ray diffraction and anomalous X-ray scattering were used for characterizing the influence of manganese on iron oxyhydroxides and oxides formed from green rust (GR) in an aqueous solution. The results showed that the formation of Fe 3O 4 was enhanced by the addition of manganese ions during the conversion of GR2 ( SO 4 2 - ) to α-FeOOH and Fe 3O 4. The results obtained from anomalous X-ray scattering showed that manganese was present both in α-FeOOH and Fe 3O 4 particles. The incorporation of manganese in α-FeOOH appears to induce the distortion of the atomic-scale structure of α-FeOOH particles formed in an aqueous solution.

The role of phosphate groups in the VS ribozyme-substrate interaction

The VS ribozyme trans-cleavage substrate interacts with the catalytic RNA via tertiary interactions. To study the role of phosphate groups in the ribozyme-substrate interaction, 18 modified substrates were synthesized, where an epimeric phosphorothioate replaces one of the phosphate diester linkages. Sites in the stem-loop substrate where phosphorothioate substitution impaired reaction cluster in two regions. The first site is the scissile phosphate diester linkage and nucleotides downstream of this and the second site is within the loop region. The addition of manganese ions caused recovery of the rate of reaction for phosphorothioate substitutions between A621 and A622 and U631 and C632, suggesting that these two phosphate groups may serve as ligands for two metal ions. In contrast, significant manganese rescue was not observed for the scissile phosphate diester linkage implying that electrophilic catalysis by metal ions is unlikely to contribute to VS ribozyme catalysis. In addition, an increase in the reaction rate of the unmodified VS ribozyme was observed when a mixture of magnesium and manganese ions acted as the cofactor. One possible explanation for this effect is that the cleavage reaction of the VS ribozyme is rate limited by a metal dependent docking of the substrate on the ribozyme.

Effect of microelements on the biosynthesis of secondary metabolites by the fungusPenicillium citrinum thom VKM F-1079

Penicillium citrinum VKM F-1079 was found to produce clavine ergot alkaloids and citrinin, a secondary O-heterocyclic metabolite. Citrinin was produced in the idiophase, whereas the production of ergot alkaloids paralleled fungal growth. The addition of manganese ions to the growth medium stimulated the biosynthesis of both citrinin and ergot alkaloids. Zinc ions stimulated only citrinin synthesis. The presence of these microelements in the growth medium influenced the proportion between the ergot alkaloids synthesized. Copper, manganese, and iron ions affected but little fungal growth and alkaloid production. The effect of microelements on the main kinetic parameters of growth and alkaloid production was studied.

Manganese-catalysed ozonation of glyoxalic acid in aqueous solutions

Manganese-catalysed ozonation of glyoxalic acid in aqueous solutions has been investigated in the pH range 2.0-4.0. The addition of manganese ions (Mn(II) or Mn(IV)) to a glyoxalic acid-ozone system allows the substrate to be oxidized through a mechanism different from that reported for uncatalysed ozonation, as underlined by the formation of methanoic acid. The presence of solid MnO2 results in a further increase in the system reactivity. High levels of mineralization are generally achieved during glyoxalic acid-catalysed ozonation. # 2000 Society of Chemical Industry

Non-heme hydroquinone peroxidase from Azotobacter beijerinckii HM121

In order to purify a lignin-degrading enzyme from the bacterium Azotobacter beijerinckii HM121, which rapidly decolorizes lignin, the enzyme activity was monitored by observing the hydroquinone oxidizing activity in the presence of hydrogen peroxide. The activity was bound to the membrane and was solubilized by treating disrupted cells with 0.1% Triton X-100. The enzyme was purified to homogeneity by ammonium sulfate fractionation, hydrophobic chromatography on butyl-Toyopearl 650M, and gel filtration on Toyopearl HW-55F. The relative molecular mass of the enzyme was determined to be 59,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 55,000 by gel filtration on Toyopearl HW-55F, suggesting it is a monomeric enzyme. The purified enzyme exhibited the maximal activity for hydroquinone oxidation at pH 7.0 and 50°C and was stable up to 70°C for 1 h. The optimum concentration of hydrogen peroxide was 6.0 mM. The enzyme was active toward hydroquinone, vanillin, catechol, caffeic acid, p-phenylenediamine, pyrogallol, methylhydroquinone, and dimethylhydroquinone. Based on these results the enzyme was named hydroquinone peroxidase. The enzyme also decolorized and degraded lignin. Spectral analysis revealed that this peroxidase did not have iron-heme. Inductively coupled plasma analysis showed the presence of equimolar manganese. The enzyme activity was inhibited by 1 mM EDTA and by 1 mM 1,10-phenanthroline; the activity of the EDTA-inactivated enzyme was restored by the addition of manganese ions. However, the enzyme activity did not require exogenous manganese ions and was not promoted by the addition of manganese. The peroxidase oxidized Mn(II) to Mn(III) in the presence of hydrogen peroxide. The activity was promoted 4 fold by the addition of 0.1 mM ZnCl 2. The enzyme formed a hydroxy radical from hydrogen peroxide as an active oxygen molecule. From the above results, the hydroquinone peroxidase was judged to be a new type of lignin-degrading enzyme.

In situ detection of constitutive superoxide anion production in granules of mast cells.

3,3'-Diaminobenzidine, in the presence of manganese and cobalt ions, was applied for the detection of superoxide anions in unfixed cryostat sections of rat oesophagus, trachea, skin and intact mesenterium. In all connective tissues, a blue final reaction product was found in a granular form in mast cells. The amount of final reaction product formed after incubation with diaminobenzidine and cobalt ions was increased by the addition of manganese ions. Electron microscopical analysis revealed that the electron-dense final reaction product was exclusively present in the granules of mast cells and on elastin fibres. It was found that the constitutive spontaneous formation of final reaction product in mast cells was enzymatic and dependent on the presence of oxygen in the medium. Of all the enzyme inhibitors and free radical scavengers tested, only azide strongly reduced the amount of final reaction product. It was concluded that the reaction was partly caused by peroxidase activity, but that superoxide anions are also constitutively and spontaneously produced in mast cell granules. The exact enzymatic source could not be established. Whether this property of mast cell granules plays an antimicrobial role in connective tissues can only be speculated.

Trehalose Production by a Strain ofMicrococcus varians

A bacterium isolated from soil was found to accumulate abundant trehalose in its medium. The bacterium was identified as a strain of Micrococcus varians from its taxonomical characteristics and was designated M. varians strain No. 39. Several other strains of Micrococcus and Deinococcus also accumulated extracellular trehalose but M. varians strain No. 39 produced the largest amount. Addition of manganese ions, and excess thiamine and nicotinamide, stimulated trehalose accumulation. Addition of 20 g/liter CSL led to the maximum conversion yield of trehalose in the production phase. Keeping the pH of the culture broth at 6.0 facilitated the maximum trehalose production rate. Cultivation of strain No. 39 at 32°C during the growth phase and 34°C during the production phase resulted in maximal trehalose production. Trehalose non-assimilating mutants (strain No. 7 and 9) derived from strain No. 39 accumulated about 15% more trehalose than the parent strain. Strain No. 7 produced 40 mg/ml trehalose from 100 mg/ml glucose under optimized conditions in a 5-liter jar fermentor.

Measurement of neutrophil and eosinophil adhesion to E-selectin, VCAM-1, and ICAM-1 by the use of tranfected fibroblast cell lines

A method which enables the specific measurement of neutrophil and eosinophil adhesion to the endothelial cell adherence receptors E-selectin, VCAM-1 and ICAM-1 has been developed. The method is based on continuous cultures of cell lines of transfected hamster kidney fibroblasts (BHK-21), that selectively express each of the endothelial cell adhesions molecules. Isolated granulocytes are added to the cultured adherent fibroblasts at a ratio of 20:1 and the cells are coincubated for 60 min at 37°C. After removal of the nonadherent granulocytes the amount of adherent granulocytes could be measured by addition of detergent and a peroxidase substrate. Selective measurement of neutrophil and eosinophil adhesion was accomplished by addition of detergent to the adherent cells, collection of extracts followed by measurement of the concentration of an eosinophil (eosinophil cationic protein) and a neutrophil (myeloperoxidase) granule protein, respectively, in the extracts. At basal conditions neutrophils and eosinophils showed significant adhesion to E-selectin and eosinophils a low degree of adhesion to VCAM-1. Significant adhesion of neutrophils and eosinophils to ICAM-1 and of eosinophils to VCAM-1 was selectively induced by addition of manganese ions (Mn 2+) at a concentration of 0.5 mmol/1. Neutrophils demonstrated a significantly higher adhesion to E-selectin than eosinophils, while eosinophil adhesion to ICAM-1 was significantly higher than that of neutrophils. In conclusion, a method to compare the adhesive capacity of neutrophil and eosinophil granulocytes towards specific endothelial cell adhesion molecules has been developed.

Manganese as a controlling factor in mixed cultures of Lactobacillus plantarum and enterobacteriaceae

Addition of manganese, at levels of 50 ppm, to a liquid growth medium simulating adverse silage conditions had no effect on the growth or on the fermentation pattern of Enterobacter cloacae and Proteus vulgaris. Yet, the manganese strongly enhanced the growth of Lactobacillus plantarum. Co-cultures of L. plantarum and E. cloacae or P. vulgaris were, by addition of manganese ions, significantly altered in the favour of the former. This finding can be of use in mixed cultures where Enterobacteriaceae act as spoiler microorganisms.

Fluorescence measurements of free Ca 2+ concentration in human erythrocytes using the Ca 2+-indicator fura-2

We report here the use of the fluorescent Ca 2+-chelator fura-2 to directly measure free Ca 2+ concentration within intact human erythrocytes and the influence of viscosity on the fluorescence of this probe. The bright fluorescence of fura-2 has permitted the use of low concentrations of indicator and cells, thus minimizing the screening effect and the intrinsic fluorescence of haemoglobin. Erythrocytes (10 8 cells/ml) were loaded with 0.5 μM fura-2AM then diluted at 10 7 cells per ml for measurements. The extracellular signal was suppressed by addition of manganese ions just before recording spectra. Under these conditions, a blood sample of 100 μl was sufficient for analysis. To study the influence of viscosity on fura-2 fluorescence, gelatin and polyvinylpyrrolidone at various concentrations were added to a physiological buffer to perform fura-2-Ca fluorescence standard curves. Fluorescence intensities and the apparent affinity constant for Ca 2+ were modified by viscosity. When intra-erythrocytic viscosity was simulated with 21 g/l polyvinylpyrrolidone to obtain a mean viscosity of 14 mPa.s similar to that observed in human erythrocytes, the mean value of free Ca 2+ concentration measured in erythrocytes from healthy subjects was 78 ± 16 nM (mean ± S.D., n = 29).

Identification of the apparently lymphocyte-specific human liver-derived inhibitory protein (LIP) as cytoplasmic liver L-arginase.

This paper describes the identification of a human liver-derived inhibitory protein (LIP), which has recently been purified, as cytoplasmic liver arginase. Arginase activity was purified to homogeneity parallel to lymphocyte proliferation inhibitory activity. The reaction products were identified by thin-layer chromatography to be ornithine and urea from arginine. The enzyme activity could be increased by the addition of manganese ions, and the inhibitory effect on cell proliferation could be reversed by additional arginine. An antiserum against LIP cross-reacted with cytoplasmic calf liver arginase.