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Sample records for acidithiobacillus ferrooxidans metabolism

  1. Acidithiobacillus ferrooxidans metabolism: from genome sequence to industrial applications

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    Blake Robert

    2008-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is a major participant in consortia of microorganisms used for the industrial recovery of copper (bioleaching or biomining. It is a chemolithoautrophic, γ-proteobacterium using energy from the oxidation of iron- and sulfur-containing minerals for growth. It thrives at extremely low pH (pH 1–2 and fixes both carbon and nitrogen from the atmosphere. It solubilizes copper and other metals from rocks and plays an important role in nutrient and metal biogeochemical cycling in acid environments. The lack of a well-developed system for genetic manipulation has prevented thorough exploration of its physiology. Also, confusion has been caused by prior metabolic models constructed based upon the examination of multiple, and sometimes distantly related, strains of the microorganism. Results The genome of the type strain A. ferrooxidans ATCC 23270 was sequenced and annotated to identify general features and provide a framework for in silico metabolic reconstruction. Earlier models of iron and sulfur oxidation, biofilm formation, quorum sensing, inorganic ion uptake, and amino acid metabolism are confirmed and extended. Initial models are presented for central carbon metabolism, anaerobic metabolism (including sulfur reduction, hydrogen metabolism and nitrogen fixation, stress responses, DNA repair, and metal and toxic compound fluxes. Conclusion Bioinformatics analysis provides a valuable platform for gene discovery and functional prediction that helps explain the activity of A. ferrooxidans in industrial bioleaching and its role as a primary producer in acidic environments. An analysis of the genome of the type strain provides a coherent view of its gene content and metabolic potential.

  2. Visualization of capsular polysaccharide induction in Acidithiobacillus ferrooxidans

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    Bellenberg, S.; Leon Morales, C.F.; Sand, W.; Vera, M.

    2012-01-01

    Extracellular Polymeric Substances (EPS) are of fundamental importance for attachment to metal sulfides, biofilm formation and leaching efficiency of Acidithiobacillus ferrooxidans. In this work we have visualized the capsular polysaccharides (CPS) of A. ferrooxidans ATCC 23270 using the

  3. Pyrite oxidation by Acidithiobacillus ferrooxidans bacteria

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    Savić Dragiša S.

    2005-01-01

    Full Text Available The kinetic model of pyrite particle dissolution by the action of bacteria Acidithiobacillus ferrooxidans in a shaken Erlenmeyer flask was presented. The model agreed well with the experimental data for the extracted iron and the number of cells in the liquid phase. The specific growth rate of the adsorbed cells was evaluated (μA = 1,6 d-1 by fitting the experimental data to the model curve. Also, the relevance of the two proposed mechanisms for the bacterial dissolution of sulphide (direct and indirect was discussed, indicating that the indirect one was dominant. The adsorption process of A. ferrooxidans to the pyrite surface was well correlated by a Langmuir type isotherm.

  4. Impact of solvent extraction organics on bioleaching by Acidithiobacillus ferrooxidans

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    Yu, Hualong; Liu, Xiaorong; Shen, Junhui; Chi, Daojie

    2017-03-01

    Solvent extraction organics (SX organics) entrained and dissoluted in the raffinate during copper SX operation, can impact bioleaching in case of raffinate recycling. The influence of SX organics on bioleaching process by Acidithiobacillus ferrooxidans (At. ferrooxidans) has been investigated. The results showed that, cells of At. ferrooxidans grew slower with contaminated low-grade chalcopyrite ores in shaken flasks bioleaching, the copper bioleaching efficiency reached 15%, lower than that of 24% for uncontaminated minerals. Obviously, the SX organics could adsorb on mineral surface and hinder its contact with bacterials, finanlly lead to the low bioleaching efficiency.

  5. Arsenic Precipitation in the Bioleaching of Realgar Using Acidithiobacillus ferrooxidans

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    Peng Chen

    2013-01-01

    Full Text Available The current study investigates the characteristics of arsenic precipitation during the bioleaching of realgar. The bioleaching performance of Acidithiobacillus ferrooxidans BY-3 (A. ferrooxidans was investigated through scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Fourier transform infrared (FT-IR spectrophotometry. SEM and XRD analyses revealed that the arsenic-adapted strain of A. ferrooxidans was more hydrophobic and showed higher attachment efficiency to realgar compared with the wild strain. The arsenic precipitation using A. ferrooxidans resulted in the precipitation of an arsenic-rich compound on the surface of the bacterial cell, as shown in the TEM images. The FT-IR spectra suggested that the −OH and −NH groups were closely involved in the biosorption process. The observations above strongly suggest that the cell surface of A. ferrooxidans plays a role in the induction of arsenic tolerance during the bioleaching of realgar.

  6. Biocompatibility evaluation of magnetosomes formed by Acidithiobacillus ferrooxidans

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    Yan Lei [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China); College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 (China); Yue Xiaoxuan [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China); Zhang Shuang [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 (China); Chen Peng [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China); GIBT, Gansu Institute of Business and Technology, Yannan Road 18, Lanzhou, 730010 (China); Xu Zhiliang; Li Yang [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China); Li Hongyu, E-mail: hekouyanlei@gmail.com [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China)

    2012-10-01

    Magnetite nanocrystal has been extensively used in biomedical field. Currently, an interesting alternative to synthetic magnetic Fe{sub 3}O{sub 4} nanoparticles, called magnetosome, has been found in magnetotactic bacteria. It has been reported that Acidithiobacillus ferrooxidans (At. ferrooxidans) has a potential to synthesize magnetosome. In this study, transmission electron microscope (TEM) was used to analyze the magnetite particles in At. ferrooxidans BY-3. The magnetosomes formed by this bacterium were isolated by a method combining ultracentrifugation and magnetic separation. Crystalline phase and surface functional group of the magnetosomes were investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Biocompatibility of the magnetosomes was systematically evaluated at various concentrations (0.5, 1.0, 2.0 and 4.0 mg/ml). MTT test, hemolysis assay and Micronucleus Test were carried out to evaluate in vitro cytotoxicity, blood toxicity and genotoxicity of magnetosomes, respectively. Under these conditions, magnetosomes showed no cytotoxic, genotoxic and hemolytic effects up to 4.0 mg/ml indicating good biocompatibility of these biological nanoparticles. These revealed that the magnetosomes might have a potential for biotechnological and biomedical applications in the future. - Highlights: Black-Right-Pointing-Pointer The production of magnetosomes from At. ferrooxidans has been easily available. Black-Right-Pointing-Pointer Several techniques are used to characterize properties of the magnetosomes. Black-Right-Pointing-Pointer The magnetosomes have no cytotoxicity, no hemolysis activity and no genotoxicity.

  7. Valorization of Phosphorus Secondary Raw Materials by Acidithiobacillus ferrooxidans.

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    Wyciszkiewicz, Małgorzata; Saeid, Agnieszka; Malinowski, Przemysław; Chojnacka, Katarzyna

    2017-03-16

    This paper presents the possibility of producing phosphorus fertilizers through Acidithiobacillus ferrooxidans utilization in secondary raw materials solubilization. Phosphorus was obtained from the bones of poultry and fish as well as from Morocco phosphorite. Four doses of poultry bones and fish bones were used in the experiment (2, 4, 10 and 20 g/L) and two doses (2 and 4 g/L) of phosphorite were also used. The experimenters measured the final pH, which increased in proportion to the increase in the number of poultry bone doses, whereas in the case of fish bones it decreased in proportion to the increase in the number of fish bone doses. Only in the case of phosphorite, where 10 g/L were used, there was a slight increase in pH during solubilization observed. The highest phosphorus concentration of 1.9% (expressed as P₂O₅) was found for the solubilization performed on fish bones with the highest dose (20 g/L). The formulation obtained in this study meets the necessary requirements for use as a bio-fertilizer because of the relatively low content of P₂O₅ and the low content of toxic elements. The results confirm the utilization of Acidithiobacillus ferrooxidans in the biosolubilization of phosphorus renewable raw materials that can alleviate the problem of the world's depleting phosphorite deposits.

  8. Differential expression of sulfur assimilation pathway genes in Acidithiobacillus ferrooxidans under Cd²⁺ stress: evidence from transcriptional, enzymatic, and metabolic profiles.

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    Zheng, Chunli; Chen, Minjie; Tao, Zhanlong; Zhang, Li; Zhang, Xue Feng; Wang, Jian-Ying; Liu, Jianshe

    2015-03-01

    Acidithiobacillus ferrooxidans is a heavy metal-tolerant acidophilic chemolithotroph found in acidic mine effluent and is used commercially in the bioleaching of sulfide ores. In this work, we investigated the interplay between divalent cadmium (Cd(2+)) resistance and expression of genes involved in the sulfur assimilation pathway (SAP). We also investigated the response of the thiol-containing metal-chelating metabolites, cysteine and glutathione(GSH), to increasing Cd(2+) concentrations. During growth in the presence of 30 mM Cd(2+), the concentrations of mRNA for 5 genes in the SAP pathway increased more than fourfold: these encode ATP sulfurylase (ATPS), adenosine 5'-phosphosulfate (APS) reductase, sulfite reductase (SiR), serine acetyltransferase (SAT) and O-acetylserine (thiol) lyase (OAS-TL). Increased transcription was also reflected in increased enzyme activities: those of SAT and adenosylphosphosulfate reductase (APR) reached a peak of 26- and 15.8-fold, respectively, compared to the control culture in the presence of 15 mM Cd(2+). In contrast, the activity of OAS-TL, which is responsible for the biosynthesis of cysteine, was diminished. At the metabolite level, the intracellular cysteine and GSH contents nearly doubled. These results suggested that Cd(2+) induced transcription of SAP genes, while directly inhibiting the activities of some enzymes (e.g., OAS-TL). Overall, these results are consistent with a detoxification/resistance mechanism involving enhanced sulfur uptake and sequestration of Cd(2+) by cysteine and glutathione.

  9. Ex-situ bioremediation of U(VI from contaminated mine water using Acidithiobacillus ferrooxidans strains

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    Maria eRomero-Gonzalez

    2016-05-01

    Full Text Available The ex-situ bioremoval of U(VI from contaminated water using Acidithiobacillus ferrooxidans strain 8455 and 13538 was studied under a range of pH and uranium concentrations. The effect of pH on the growth of bacteria was evaluated across the range 1.5 – 4.5 pH units. The respiration rate of At. ferrooxidans at different U(VI concentrations was quantified as a measure of the rate of metabolic activity over time using an oxygen electrode. The biosorption process was quantified using a uranyl nitrate solution, U-spiked growth media and U-contaminated mine water. The results showed that both strains of At. ferrooxidans are able to remove U(VI from solution at pH 2.5 – 4.5, exhibiting a buffering capacity at pH 3.5. The respiration rate of the micro-organism was affected at U(VI concentration of 30 mg L-1. The kinetics of the sorption fitted a pseudo-first order equation, and depended on the concentration of U(VI. The KD obtained from the biosorption experiments indicated that strain 8455 is more efficient for the removal of U(VI. A bioreactor designed to treat a solution of 100 mg U(VI L-1 removed at least 50% of the U(VI in water. The study demonstrated that At. ferrooxidans can be used for the ex-situ bioremediation of U(VI contaminated mine water.

  10. [Difference in acclimation of Acidithiobacillus ferrooxidans by various substrates and its effect on coal desulfurization efficiency].

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    Zhang, De-Wei; Zhou, Li-Xiang; Yang, Xin-Ping; Wang, Shi-Mei

    2011-01-01

    In this study, Acidithiobacillus ferrooxidans LX5 was cultured in 9K medium with pyrite and ferrous sulfate as the substrates. Results showed that the number of A. ferrooxidans LX5 acclimated by pyrite for 20 d was 3.0 x 10(7) cell/mL in the liquid, and the oxidation activity to pyrite was stronger. A. ferrooxidans LX5 cultured for 48 h was 1.0 x 10(8) cell/mL in medium with FeSO4. Extracellular polymeric substance (EPS) produced from A. ferrooxidans LX5 acclimated by pyrite was 2 395 microg/(10(10) cells) three times as much as that cultured with FeSO4. A high-sulfur coal desulfurization experiment were carried out with A. ferrooxidans LX5 domesticated respectively in medium with ferrous sulfate and pyrite. The results showed that the coal desulfurization rate was up to 72.4% after bioleaching for 13 d by A. ferrooxidans LX5 acclimated by pyrite, at the same time, the desulfurization rate was only 47.2% with A. ferrooxidans LX5 cultured with ferrous sulfate and reached 65.8% in 20 d. Therefore, the desulfurization efficiency can be improved of coal and shorten the desulfurization time when A. ferrooxidans LX5 acclimated with pyrite as the substrate.

  11. Biooxidación de concentrados de arsenopirita por Acidithiobacillus ferrooxidans en erlenmeyer agitados

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    Juan David Ospina; Erica Mejía Restrepo; Laura Osorno Bedoya; Marco Antonio Márquez; Alvaro Luis Morales

    2012-01-01

    Título en ingles: Biooxidation of arsenopyrite concentrates by Acidithiobacillus ferrooxidans in shake flasks Resumen Se evaluó el proceso de biooxidación de concentrados de arsenopirita por A. ferrooxidans ATCC 23270, previa adaptación de los microorganismos al mineral y dos tamaños de partícula, pasante malla Tyler 200 (~75μm) y 325 (~45μm). También, se determinó el grado de concentración del mineral mediante DRX y MOLPP/...

  12. Type IV pili of Acidithiobacillus ferrooxidans can transfer electrons from extracellular electron donors.

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    Li, Yongquan; Li, Hongyu

    2014-03-01

    Studies on Acidithiobacillus ferrooxidans accepting electrons from Fe(II) have previously focused on cytochrome c. However, we have discovered that, besides cytochrome c, type IV pili (Tfp) can transfer electrons. Here, we report conduction by Tfp of A. ferrooxidans analyzed with a conducting-probe atomic force microscope (AFM). The results indicate that the Tfp of A. ferrooxidans are highly conductive. The genome sequence of A. ferrooxidans ATCC 23270 contains two genes, pilV and pilW, which code for pilin domain proteins with the conserved amino acids characteristic of Tfp. Multiple alignment analysis of the PilV and PilW (pilin) proteins indicated that pilV is the adhesin gene while pilW codes for the major protein element of Tfp. The likely function of Tfp is to complete the circuit between the cell surface and Fe(II) oxides. These results indicate that Tfp of A. ferrooxidans might serve as biological nanowires transferring electrons from the surface of Fe(II) oxides to the cell surface. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. The small heat shock proteins from Acidithiobacillus ferrooxidans: gene expression, phylogenetic analysis, and structural modeling

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    Ribeiro Daniela A

    2011-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is an acidophilic, chemolithoautotrophic bacterium that has been successfully used in metal bioleaching. In this study, an analysis of the A. ferrooxidans ATCC 23270 genome revealed the presence of three sHSP genes, Afe_1009, Afe_1437 and Afe_2172, that encode proteins from the HSP20 family, a class of intracellular multimers that is especially important in extremophile microorganisms. Results The expression of the sHSP genes was investigated in A. ferrooxidans cells submitted to a heat shock at 40°C for 15, 30 and 60 minutes. After 60 minutes, the gene on locus Afe_1437 was about 20-fold more highly expressed than the gene on locus Afe_2172. Bioinformatic and phylogenetic analyses showed that the sHSPs from A. ferrooxidans are possible non-paralogous proteins, and are regulated by the σ32 factor, a common transcription factor of heat shock proteins. Structural studies using homology molecular modeling indicated that the proteins encoded by Afe_1009 and Afe_1437 have a conserved α-crystallin domain and share similar structural features with the sHSP from Methanococcus jannaschii, suggesting that their biological assembly involves 24 molecules and resembles a hollow spherical shell. Conclusion We conclude that the sHSPs encoded by the Afe_1437 and Afe_1009 genes are more likely to act as molecular chaperones in the A. ferrooxidans heat shock response. In addition, the three sHSPs from A. ferrooxidans are not recent paralogs, and the Afe_1437 and Afe_1009 genes could be inherited horizontally by A. ferrooxidans.

  14. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

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    Ellen Cristine Giese

    2015-06-01

    Full Text Available Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The column experiments inoculated with immobilized cells of A. ferrooxidans LR showed the same efficiency than the conventional method using free cells and is promising for application on a larger scale as it ensuring integrity and activity of biomining microorganisms and reduce process costs. DOI: http://dx.doi.org/10.17807/orbital.v7i2.698 

  15. Genes and pathways for CO2 fixation in the obligate, chemolithoautotrophic acidophile, Acidithiobacillus ferrooxidans, Carbon fixation in A. ferrooxidans

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    Esparza Mario

    2010-08-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is chemolithoautotrophic γ-proteobacterium that thrives at extremely low pH (pH 1-2. Although a substantial amount of information is available regarding CO2 uptake and fixation in a variety of facultative autotrophs, less is known about the processes in obligate autotrophs, especially those living in extremely acidic conditions, prompting the present study. Results Four gene clusters (termed cbb1-4 in the A. ferrooxidans genome are predicted to encode enzymes and structural proteins involved in carbon assimilation via the Calvin-Benson-Bassham (CBB cycle including form I of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO, EC 4.1.1.39 and the CO2-concentrating carboxysomes. RT-PCR experiments demonstrated that each gene cluster is a single transcriptional unit and thus is an operon. Operon cbb1 is divergently transcribed from a gene, cbbR, encoding the LysR-type transcriptional regulator CbbR that has been shown in many organisms to regulate the expression of RubisCO genes. Sigma70-like -10 and -35 promoter boxes and potential CbbR-binding sites (T-N11-A/TNA-N7TNA were predicted in the upstream regions of the four operons. Electrophoretic mobility shift assays (EMSAs confirmed that purified CbbR is able to bind to the upstream regions of the cbb1, cbb2 and cbb3 operons, demonstrating that the predicted CbbR-binding sites are functional in vitro. However, CbbR failed to bind the upstream region of the cbb4 operon that contains cbbP, encoding phosphoribulokinase (EC 2.7.1.19. Thus, other factors not present in the assay may be required for binding or the region lacks a functional CbbR-binding site. The cbb3 operon contains genes predicted to encode anthranilate synthase components I and II, catalyzing the formation of anthranilate and pyruvate from chorismate. This suggests a novel regulatory connection between CO2 fixation and tryptophan biosynthesis. The presence of a form II Rubis

  16. Vanadium Bioleaching Behavior by Acidithiobacillus ferrooxidans from a Vanadium-Bearing Shale

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    Dunpei Wei

    2018-01-01

    Full Text Available This study investigated bioleaching behavior of vanadium from a vanadium-bearing shale using Acidithiobacillus ferrooxidans (A. ferrooxidans. Results showed a maximum recovery of 62% vanadium in 1.2-day bioleaching, which was 22.45% higher than the controls. Then, the vanadium leaching efficiency decreased significantly, only 24% of that was obtained on the tenth day. The vanadium extraction in 1.2 days was mainly attributed to the dissolution of vanadium in free oxides of shale. Fe3+ produced by A. ferrooxidans promoted the dissolution process. X-ray diffraction (XRD patterns of the leached residues confirmed the generation of jarosite. SEM-EDS analysis of the residues indicated that jarosite adsorbed on the shale and inhibited the further dissolution of vanadium. The relevance of V, Fe, S, O was quite good in the energy disperse X-ray spectrometry (EDS element mapping of jarosite, and acid-washing of the jarosite resulted in 31.6% of the vanadium in the precipitates desorption, indicating that the decrease of vanadium leaching efficiency in bioleaching process was caused by both adsorption and co-precipitation with jarosite.

  17. Bioinformatic Prediction of Gene Functions Regulated by Quorum Sensing in the Bioleaching Bacterium Acidithiobacillus ferrooxidans

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    Alvaro Banderas

    2013-08-01

    Full Text Available The biomining bacterium Acidithiobacillus ferrooxidans oxidizes sulfide ores and promotes metal solubilization. The efficiency of this process depends on the attachment of cells to surfaces, a process regulated by quorum sensing (QS cell-to-cell signalling in many Gram-negative bacteria. At. ferrooxidans has a functional QS system and the presence of AHLs enhances its attachment to pyrite. However, direct targets of the QS transcription factor AfeR remain unknown. In this study, a bioinformatic approach was used to infer possible AfeR direct targets based on the particular palindromic features of the AfeR binding site. A set of Hidden Markov Models designed to maintain palindromic regions and vary non-palindromic regions was used to screen for putative binding sites. By annotating the context of each predicted binding site (PBS, we classified them according to their positional coherence relative to other putative genomic structures such as start codons, RNA polymerase promoter elements and intergenic regions. We further used the Multiple EM for Motif Elicitation algorithm (MEME to further filter out low homology PBSs. In summary, 75 target-genes were identified, 34 of which have a higher confidence level. Among the identified genes, we found afeR itself, zwf, genes encoding glycosyltransferase activities, metallo-beta lactamases, and active transport-related proteins. Glycosyltransferases and Zwf (Glucose 6-phosphate-1-dehydrogenase might be directly involved in polysaccharide biosynthesis and attachment to minerals by At. ferrooxidans cells during the bioleaching process.

  18. Comparison Analysis of Coal Biodesulfurization and Coal's Pyrite Bioleaching with Acidithiobacillus ferrooxidans

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    Hong, Fen-Fen; He, Huan; Liu, Jin-Yan; Tao, Xiu-Xiang; Zheng, Lei; Zhao, Yi-Dong

    2013-01-01

    Acidithiobacillus ferrooxidans (A. ferrooxidans) was applied in coal biodesulfurization and coal's pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal's pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal's pyrite bioleaching rate was 72.0%. SEM micrographs showed that the major pyrite forms in coal were massive and veinlets. It seems that the bacteria took priority to remove the massive pyrite. The sulfur relative contents analysis from XANES showed that the elemental sulfur (28.32%) and jarosite (18.99%) were accumulated in the biotreated residual coal. However, XRD and XANES spectra of residual pyrite indicated that the sulfur components were mainly composed of pyrite (49.34%) and elemental sulfur (50.72%) but no other sulfur contents were detected. Based on the present results, we speculated that the pyrite forms in coal might affect sulfur biooxidation process. PMID:24288464

  19. Surface alteration of realgar (As(4)S(4)) by Acidithiobacillus ferrooxidans.

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    Chen, Peng; Yan, Lei; Wang, Qiang; Li, Yang; Li, Hongyu

    2012-03-01

    The chemical and physical characteristics of realgar (an arsenic sulfide mineral that occurs in several crystalline forms) in the presence of Acidithiobacillus ferrooxidans BY-3 were investigated in this work. Grains of the mineral were incubated for 10, 20, and 30 days with A. ferrooxidans cultured in 9K medium at 30 °C and at 150 rpm agitation. Abiotic control experiments were conducted in identical solutions. The effect of bioleaching on the surface properties of realgar was characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), inductively coupled plasma atomic emission spectroscope (ICP-AES), X-ray diffraction (XRD), and Raman spectroscopy. SEM and EDS analyses confirmed the ability of A. ferrooxidans to modify surfaces of realgar and to efficiently enhance its dissolution. ICP-AES showed the dissolution and precipitation of realgar during bioleaching. Based on the XRD pattern and the Raman spectra, the decrease in arsenic in the liquid phase was due to co-precipitation of the mineral with Fe(III) or Fe(III) compounds (e.g., jarosite or goethite). Thus, not only did Fe(III) alter the surface of realgar, but it also promoted its dissolution during bioleaching.

  20. A Comparative Study on the Effect of Flotation Reagents on Growth and Iron Oxidation Activities of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans

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    Mohammad Jafari

    2016-12-01

    Full Text Available Recently, extraction of metals from different resources using a simple, efficient, and low-cost technique-known as bioleaching-has been widely considered, and has turned out to be an important global technology. Leptospirillum ferrooxidans and Acidithiobacillus (Thiobacillus ferrooxidans are ubiquitous bacteria in the biomining industry. To date, the effects of commercial flotation reagents on the biooxidation activities of these bacteria have not been thoroughly studied. This investigation, by using various systematic measurement methods, studied the effects of various collectors and frothers (collectors: potassium amylxanthate, potassium isobutyl-xanthate, sodium ethylxanthate, potassium isopropylxanthate, and dithiophosphate; and frothers: pine oil and methyl isobutyl carbinol on L. ferrooxidans and A. ferrooxidans activities. In general, results indicate that in the presence of these collectors and frothers, L. ferrooxidans is less sensitive than T. ferrooxidans. In addition, the inhibition effect of collectors on both bacteria is recommended in the following order: for the collectors, potassium isobutyl-xanthate > dithiophosphate > sodium ethylxanthate > potassium isobutyl-xanthate > potassium amylxanthate; and for the frothers, methyl isobutyl carbinol > pine oil. These results can be used for the optimization of biometallurgical processes or in the early stage of a process design for selection of flotation reagents.

  1. Study of Acidithiobacillus ferrooxidans and enzymatic bio-Fenton process-mediated corrosion of copper-nickel alloy.

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    Jadhav, U; Hocheng, H

    2016-10-01

    This study presents the corrosion behavior of the copper-nickel (Cu-Ni) alloy in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) and glucose oxidase (GOx) enzyme. In both the cases ferric ions played an important role in weight loss and thereby to carry out the corrosion of the Cu-Ni alloy. A corrosion rate of 0.6 (±0.008), 2.11 (±0.05), 3.69 (±0.26), 0.7 (±0.006) and 0.08 (±0.002) mm/year was obtained in 72 h using 9K medium with ferrous sulfate, A. ferrooxidans culture supernatant, A. ferrooxidans cells, GOx enzyme and hydrogen peroxide (H2O2) solution respectively. The scanning electron microscopy (SEM) micrographs showed that a variable extent of corrosion was caused by 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells. An arithmetic average surface roughness (Ra) of 174.78 nm was observed for the control work-piece using optical profilometer. The change in Ra was observed with the treatment of the Cu-Ni alloy using various systems. The Ra for 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells was 374.54, 607.32 and 799.48 nm, respectively, after 24 h. These results suggest that A. ferrooxidans cells were responsible for more corrosion of the Cu-Ni alloy than other systems used.

  2. Characterization of Extreme Acidophile Bacteria (Acidithiobacillus ferrooxidans Bioleaching Copper from Flexible PCB by ICP-AES

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    Weihua Gu

    2014-01-01

    Full Text Available In order to improve copper leaching efficiency from the flexible printed circuit board (PCB by Acidithiobacillus ferrooxidans, it is necessary to quantitatively measure the bacteria bioleaching copper under extreme acidic condition from flexible PCB. The inductively coupled plasma-atomic emission spectroscopy (ICP-AES is a very accurate way to analyze metals in solution; this paper investigated the optimal conditions for copper bioleaching by Acidithiobacillus ferrooxidans from flexible PCB through ICP-AES. The conditions included particle size of flexible PCB powder, quantity of flexible PCB powder, initial pH of culture medium, bacteria inoculation, bacteria activation time, and quantity of FeSO4·7H2O. Prior to ICP-AES measurement, culture solution was digested by aqua regia. The experimental results demonstrated that flexible PCB contained one main metal (copper; this was associated with the structure of flexible PCB. The optimization conditions were in 50 mL medium, flexible PCB 10 g/L, particle size of flexible PCB 0.42~0.84 mm, culture medium initial pH 2.5, bacteria inoculation 5%, bacteria activation time 5 d, and quantity of FeSO4·7H2O 30 g/L. Under the optimization condition, the leaching rate of copper was 90.10%, which was 42.4% higher than the blank group. For the ICP-AES determination, it reached a conclusion that the best corresponding wavelength (nm of copper will be 224.7 (nm.

  3. Biological extraction of realgar by Acidithiobacillus ferrooxidans and its in vitro and in vivo antitumor activities.

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    Zhang, Xu; Xie, Qin-Jian; Wang, Xin; Wang, Bo; Li, Hong-Yu

    2010-01-01

    Acidithiobacillus ferrooxidans is a Gram-negative, chemolithoautotrophic bacterium involved in metal bioleaching. It is used for the extraction of coarse medical realgar, which is converted into an aqueous solution. To prove its feasibility as an anticancer drug candidate, extracted realgar (ER/Af) was evaluated for its antitumor activities both in vitro and in vivo. In cytotoxicity tests, ER/Af displayed significant inhibition on cell proliferation of HepG2, SMMC7721, and H22 cells in a time and dose dependent manner. Remarkable tumor growth inhibition and survival time prolongation effects, along with no obvious toxicity, were observed in antitumor experiments against H22 cell-bearing mice. Apoptosis induction was also confirmed as one of the mechanisms involved in the efficacy of ER/Af both in vitro and in vivo. The most important observation is that ER/Af showed high selective affinity to tumor tissues with about eight-fold higher arsenic accumulations at the tumor site of mice than those of the arsenic trioxide (ATO)-treated group at the same dose (57.8 +/- 3.34 microg/g dry tissue vs. 7.6 +/- 0.88 microg/g dry tissue). In conclusion, A. ferrooxidans could be successfully used for the extraction of realgar and ER/Af was proved to be a promising anticancer drug candidate, which is valuable for further study and clinical trials.

  4. Optimization of magnetosome production by Acidithiobacillus ferrooxidans using desirability function approach

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Lei, E-mail: hekouyanlei@gmail.com [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319 (China); Zhang, Shuang [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319 (China); Liu, Hetao [School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004 (China); Wang, Weidong [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing 163319 (China); Chen, Peng; Li, Hongyu [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China)

    2016-02-01

    Present study aimed to resolve the conflict between cell growth and magnetosome formation of Acidithiobacillus ferrooxidans (A. ferrooxidans) in batch experiments by applying response surface methodology (RSM) integrated a desirability function approach. The effects of several operating parameters on cell growth (OD{sub 600}) and magnetosome production (C{sub mag}) were evaluated. The maximum overall desirability (D) of 0.923 was achieved at iron concentration of 125.07 mM, shake speed of 122.37 rpm and nitrogen concentration of 2.40 g/L. Correspondingly, the OD{sub 600} and C{sub mag} were 0.522 and 1.196, respectively. The confirmation experiment confirmed that the optimum OD{sub 600} and C{sub mag} obtained were in good agreement with the predicted values. The inductively coupled plasma atomic emission spectrometer (ICP-AES) and transmission electron microscopy (TEM) analyses revealed that the production of magnetosomes could be improved via optimization. X-ray diffraction (XRD) showed the magnetosomes are magnetite. Results indicated that RSM with a desirability function was a useful technique to get the maximum OD{sub 600} and C{sub mag} simultaneously. - Highlights: • Optimization of magnetosome production by A. ferrooxidans using BBD of RSM. • Desirability function was used for concurrent maximization of cell and magnetosome yield. • ICP-AES results showed an increase in intracellular iron content through optimizing. • TEM showed a 2.5 fold increase in magnetosome number after optimization. • The methodology demonstrated a useful tool with an overall desirability of 0.923.

  5. A genomic island provides Acidithiobacillus ferrooxidans ATCC 53993 additional copper resistance: a possible competitive advantage.

    Science.gov (United States)

    Orellana, Luis H; Jerez, Carlos A

    2011-11-01

    There is great interest in understanding how extremophilic biomining bacteria adapt to exceptionally high copper concentrations in their environment. Acidithiobacillus ferrooxidans ATCC 53993 genome possesses the same copper resistance determinants as strain ATCC 23270. However, the former strain contains in its genome a 160-kb genomic island (GI), which is absent in ATCC 23270. This GI contains, amongst other genes, several genes coding for an additional putative copper ATPase and a Cus system. A. ferrooxidans ATCC 53993 showed a much higher resistance to CuSO(4) (>100 mM) than that of strain ATCC 23270 (<25 mM). When a similar number of bacteria from each strain were mixed and allowed to grow in the absence of copper, their respective final numbers remained approximately equal. However, in the presence of copper, there was a clear overgrowth of strain ATCC 53993 compared to ATCC 23270. This behavior is most likely explained by the presence of the additional copper-resistance genes in the GI of strain ATCC 53993. As determined by qRT-PCR, it was demonstrated that these genes are upregulated when A. ferrooxidans ATCC 53993 is grown in the presence of copper and were shown to be functional when expressed in copper-sensitive Escherichia coli mutants. Thus, the reason for resistance to copper of two strains of the same acidophilic microorganism could be determined by slight differences in their genomes, which may not only lead to changes in their capacities to adapt to their environment, but may also help to select the more fit microorganisms for industrial biomining operations. © Springer-Verlag 2011

  6. Characterization of bornite (Cu5FeS4) electrodes in the presence of the bacterium Acidithiobacillus ferrooxidans

    OpenAIRE

    Bevilaqua,Denise; Diéz-Perez,Ismael; Fugivara,Cecílio S.; Sanz,Fausto; Garcia Jr.,Oswaldo; Benedetti,Assis V.

    2003-01-01

    Bornite electrodes were characterized in the absence or in the presence of Acidithiobacillus ferrooxidans, which is an important microorganism involved in metal bioleaching processes. The presence of the bacterium modified the mineral/electrolyte interface, increasing the corrosion rate, as revealed by interferometric, AEM, ICP and EIS analyses. As a consequence of bacterial activity the electrode became porous, increasing its surface heterogeneity. This behavior was correlated with the evolu...

  7. Ferrous iron oxidation by foam immobilized Acidithiobacillus ferrooxidans: Experiments and modeling.

    Science.gov (United States)

    Jaisankar, S; Modak, J M

    2009-01-01

    Ferrous iron bio-oxidation by Acidithiobacillus ferrooxidans immobilized on polyurethane foam was investigated. Cells were immobilized on foams by placing them in a growth environment and fully bacterially activated polyurethane foams (BAPUFs) were prepared by serial subculturing in batches with partially bacterially activated foam (pBAPUFs). The dependence of foam density on cell immobilization process, the effect of pH and BAPUF loading on ferrous oxidation were studied to choose operating parameters for continuous operations. With an objective to have high cell densities both in foam and the liquid phase, pretreated foams of density 50 kg/m(3) as cell support and ferrous oxidation at pH 1.5 to moderate the ferric precipitation were preferred. A novel basket-type bioreactor for continuous ferrous iron oxidation, which features a multiple effect of stirred tank in combination with recirculation, was designed and operated. The results were compared with that of a free cell and a sheet-type foam immobilized reactors. A fivefold increase in ferric iron productivity at 33.02 g/h/L of free volume in foam was achieved using basket-type bioreactor when compared to a free cell continuous system. A mathematical model for ferrous iron oxidation by Acidithiobacillus ferrooxidans cells immobilized on polyurethane foam was developed with cell growth in foam accounted by an effectiveness factor. The basic parameters of simulation were estimated using the experimental data on free cell growth as well as from cell attachment to foam under nongrowing conditions. The model predicted the phase of both oxidation of ferrous in shake flasks by pBAPUFs as well as by fully activated BAPUFs for different cell loadings in foam. Model for stirred tank basket bioreactor predicted within 5% both transient and steady state of the experiments closely for the simulated dilution rates. Bio-oxidation at high Fe(2+) concentrations were simulated with experiments when substrate and product

  8. The environmental context of Acidithiobacillus ferrooxidans and its potential role as an ecosystem engineer in sulphidic mine waste

    Energy Technology Data Exchange (ETDEWEB)

    Ebenaa, Gustav

    2001-06-01

    Microorganisms are the causative agent of the environmental problems since they catalyse the weathering of the (sulphidic) waste. The chemical oxidation alone is not fast enough to create any severe environmental problems. Acidithiobacillus ferrooxidans is thought to be a key organism in weathering of sulphide minerals. A. ferrooxidans is affected by several more or less abiotic factors. The influence of temperature, pH and nutrient deficiency as potentially limiting factors for the activity of A. ferrooxidans has been investigated. It seems that temperature has less influence on its activity, but rather reflects the origin of the bacterial isolate. An alkaline pH seems enough to hinder growth and activity. The nutrients do not seem to be a limiting factor in the studied environment. The possible regulation of the activity of A. ferrooxidans is therefore a way to, at least partly, mitigate the environmental impact from mine waste. Waste from the mining industry is the largest waste problem in Sweden. With amounts over 600 million tonnes one could easily imagine the tremendous cost involved in the abatement. The MiMi-programme, with researchers from several relevant fields, has as its aim to evaluate present and to find alternative techniques to mitigate the environmental impact from mine waste. The understanding of A. ferrooxidans and its role as an ecosystem engineer is essential both in evaluating present techniques and even more so in finding alternative abatement techniques for sulphidic mine waste.

  9. Ferrous iron oxidation by sulfur-oxidizing Acidithiobacillus ferrooxidans and analysis of the process at the levels of transcription and protein synthesis.

    Science.gov (United States)

    Kucera, Jiri; Bouchal, Pavel; Lochman, Jan; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

    2013-04-01

    In contrast to iron-oxidizing Acidithiobacillus ferrooxidans, A. ferrooxidans from a stationary phase elemental sulfur-oxidizing culture exhibited a lag phase in pyrite oxidation, which is similar to its behaviour during ferrous iron oxidation. The ability of elemental sulfur-oxidizing A. ferrooxidans to immediately oxidize ferrous iron or pyrite without a lag phase was only observed in bacteria obtained from growing cultures with elemental sulfur. However, these cultures that shifted to ferrous iron oxidation showed a low rate of ferrous iron oxidation while no growth was observed. Two-dimensional gel electrophoresis was used for a quantitative proteomic analysis of the adaptation process when bacteria were switched from elemental sulfur to ferrous iron. A comparison of total cell lysates revealed 39 proteins whose increase or decrease in abundance was related to this phenotypic switching. However, only a few proteins were closely related to iron and sulfur metabolism. Reverse-transcription quantitative PCR was used to further characterize the bacterial adaptation process. The expression profiles of selected genes primarily involved in the ferrous iron oxidation indicated that phenotypic switching is a complex process that includes the activation of genes encoding a membrane protein, maturation proteins, electron transport proteins and their regulators.

  10. [Bioleaching kinetic of a pyrite mining residue using organic wastes as culture media for Acidithiobacillus ferrooxidans].

    Science.gov (United States)

    Drogui, P; Picher, S; Mercier, G; Blais, J F

    2003-11-01

    In this study, the results of the leaching of metal sulphide concentrate using organic wastes as culture media for Acidithiobacillus ferrooxidans are summarized. These results indicate that the liquid fraction of municipal sewage sludge, paper mill sludge and pig manure, containing 10% (w v(-1)) pulp density of a pyritic mine waste concentrate can support the growth of the leaching bacteria and allow metal solubilization. The inhibition by dissolved organic carbon (DOC) appeared when the concentration in pig manure liquid fraction and sewage sludge filtrate is higher than 180 mg l(-1) and 500 mg l(-1), respectively. However, increase in organic concentration up to 650 mg l(-1) using paper mill sludge supernatant had no inhibitory effect on the bacterial growth. An important decrease of the DOC has been measured during all bioleaching tests. The organic matter was probably consumed by heterotrophic microorganisms activity. The growth rate of the iron-oxidizing bacteria varied from 0.05 to 0.07 h(-1). The dissolution of pyrite (FeS2) in organic waste media led to a yield of Fe solubilization of about 35%. Copper and zinc were also solubilized during the bioleaching tests. The yields of Cu and Zn solubilization ranged from 12 to 24%.

  11. Laboratory chalcopyrite oxidation by Acidithiobacillus ferrooxidans: Oxygen and sulfur isotope fractionation

    Science.gov (United States)

    Thurston, R.S.; Mandernack, K.W.; Shanks, Wayne C.

    2010-01-01

    Laboratory experiments were conducted to simulate chalcopyrite oxidation under anaerobic and aerobic conditions in the absence or presence of the bacterium Acidithiobacillus ferrooxidans. Experiments were carried out with 3 different oxygen isotope values of water (??18OH2O) so that approach to equilibrium or steady-state isotope fractionation for different starting conditions could be evaluated. The contribution of dissolved O2 and water-derived oxygen to dissolved sulfate formed by chalcopyrite oxidation was unambiguously resolved during the aerobic experiments. Aerobic oxidation of chalcopyrite showed 93 ?? 1% incorporation of water oxygen into the resulting sulfate during the biological experiments. Anaerobic experiments showed similar percentages of water oxygen incorporation into sulfate, but were more variable. The experiments also allowed determination of sulfate-water oxygen isotope fractionation, ??18OSO4-H2O, of ~ 3.8??? for the anaerobic experiments. Aerobic oxidation produced apparent ??SO4-H2O values (6.4???) higher than the anaerobic experiments, possibly due to additional incorporation of dissolved O2 into sulfate. ??34SSO4 values are ~ 4??? lower than the parent sulfide mineral during anaerobic oxidation of chalcopyrite, with no significant difference between abiotic and biological processes. For the aerobic experiments, a small depletion in ??34SSO4 of ~- 1.5 ?? 0.2??? was observed for the biological experiments. Fewer solids precipitated during oxidation under aerobic conditions than under anaerobic conditions, which may account for the observed differences in sulfur isotope fractionation under these contrasting conditions. ?? 2009 Elsevier B.V.

  12. Comparative study of simultaneous removal of As, Cu, and Pb using different combinations of electrokinetics with bioleaching by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Kim, Hyun-A; Lee, Keun-Young; Lee, Byung-Tae; Kim, Soon-Oh; Kim, Kyoung-Woong

    2012-11-01

    Different designs of electrokinetics were applied to simultaneously remove arsenic, copper, and lead from contaminated soils. Single electrokinetics (control) resulted in superior removal efficiencies for Cu (73.5%) and Pb (88.5%), though the removal of As (3.11%) was relatively little. Sequential bioelectrokinetics of bioleaching with Acidithiobacillus ferrooxidans and electrokinetics enhanced the removal of As (25%), while Pb exhibited a significant decrease in removal efficiency (10.6%), due to the formation of insoluble compounds. In order to improve the overall performance, integrated bioelectrokinetics was designed by inoculating A. ferrooxidans into the electrolyte after 5 or 15 days of electrokinetics. Lead (75.8%) and copper (72%) were effectively removed through electrokinetics, after which arsenic (35%) was more efficiently removed by bioleaching-enhanced electrokinetics. A pilot-scale experiment indicated that integrated bioelectrokinetics is an effective means of remediation of soils contaminated with multiple heavy metals and arsenic. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Bioleaching of realgar by Acidithiobacillus ferrooxidans using ferrous iron and elemental sulfur as the sole and mixed energy sources.

    Science.gov (United States)

    Chen, Peng; Yan, Lei; Leng, Feifan; Nan, Wenbing; Yue, Xiaoxuan; Zheng, Yani; Feng, Na; Li, Hongyu

    2011-02-01

    The characteristics of the bioleaching of realgar by Acidithiobacillus ferrooxidans BY-3 (A. ferrooxidans) were investigated in this work. We examined the effects of using ferrous iron and elemental sulfur as the sole and mixed energy sources on the bioleaching of realgar. Under all experimental conditions, A. ferrooxidans BY-3 significantly enhanced the dissolution of realgar. Moreover, arsenic was more efficiently leached using A. ferrooxidans BY-3 in the presence of ferrous iron than in other culture conditions. A high concentration of arsenic was observed in the absence of alternative energy sources. This concentration was higher than that in cultures with sulfur only and lower than that in cultures with ferrous iron and sulfur. Linear or nonlinear models best fit the experimental data; the nonlinear model exhibited the dual effects of dissolution and removal on the bioleaching of realgar, whereas the linear model only applied to situations of slow bioleaching rather than removal. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  14. Synthesis of argentojarosite with simulated bioleaching solutions produced by Acidithiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Chiranjit [Department of Microbiology, Ohio State University, 484 West 12" t" h Avenue, Columbus, OH 43210 (United States); Jones, F. Sandy; Bigham, Jerry M. [School of Environment and Natural Resources, Ohio State University, 2021 Coffey Road, Columbus, OH 43210 (United States); Tuovinen, Olli H., E-mail: tuovinen.1@osu.edu [Department of Microbiology, Ohio State University, 484 West 12" t" h Avenue, Columbus, OH 43210 (United States)

    2016-09-01

    Argentojarosite (AgFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) is formed as a secondary phase in Ag-catalyzed bioleaching of chalcopyrite (CuFeS{sub 2}), but to date very little is known about the paragenesis or characteristics of this silver-containing compound. The purpose of this study was to synthesize argentojarosite via biological oxidation of 120 mM ferrous sulfate by Acidithiobacillus ferrooxidans. Because of its toxicity to A. ferrooxidans, Ag{sup +} (as AgNO{sub 3}) was added to spent culture media (pH 2) after complete oxidation of ferrous sulfate. Schwertmannite (ideally Fe{sub 8}O{sub 8}(OH){sub 6}(SO{sub 4})) was precipitated during the iron oxidation phase, and subsequent Ag{sup +} addition resulted in the formation of argentojarosite. Contact time (8 h, 5 d, and 14 d) and Ag{sup +} concentration (0, 5, 20, and 40 mM) were used as variables in these experiments. Synthesis of argentojarosite, schwertmannite and other mineral phases was confirmed through X-ray diffraction analysis. Additional analyses of solid-phase oxidation products included elemental composition, color and specific surface area. The sample synthesized in the presence of 40 mM Ag{sup +} and with 14 d contact time yielded an X-ray diffraction pattern of well crystallized argentojarosite, and its elemental composition closely matched the calculated Ag, Fe, and S contents of ideal argentojarosite. The color and surface area of the remaining samples were influenced by the presence of residual schwertmannite. This phase remained stable over the time course of 14 d when no Ag{sup +} was present in the system. When equilibrations were extended to 42 d, partial conversion of reference schwertmannite to goethite was noted in the absence of Ag. In the presence of 20 mM or 40 mM Ag over the same time course, some formation of argentojarosite was also noted. In this case, schwertmannite was the only source of Fe and SO{sub 4} for argentojarosite formation. - Highlights: • Iron-oxidizing bacteria

  15. Characterization of an OmpA-like outer membrane protein of the acidophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Manchur, Mohammed Abul; Kikumoto, Mei; Kanao, Tadayoshi; Takada, Jun; Kamimura, Kazuo

    2011-05-01

    An OmpA family protein (FopA) previously reported as one of the major outer membrane proteins of an acidophilic iron-oxidizing bacterium Acidithiobacillus ferrooxidans was characterized with emphasis on the modification by heat and the interaction with peptidoglycan. A 30-kDa band corresponding to the FopA protein was detected in outer membrane proteins extracted at 75°C or heated to 100°C for 10 min prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the band was not detected in outer membrane proteins extracted at ≤40°C and without boiling prior to electrophoresis. By Western blot analysis using the polyclonal antibody against the recombinant FopA, FopA was detected as bands with apparent molecular masses of 30 and 90 kDa, suggesting that FopA existed as an oligomeric form in the outer membrane of A. ferrooxidans. Although the fopA gene with a sequence encoding the signal peptide was successfully expressed in the outer membrane of Escherichia coli, the recombinant FopA existed as a monomer in the outer membrane of E. coli. FopA was detected in peptidoglycan-associated proteins from A. ferrooxidans. The recombinant FopA also showed the peptidoglycan-binding activity.

  16. Comparative proteomic analysis of sulfur-oxidizing Acidithiobacillus ferrooxidans CCM 4253 cultures having lost the ability to couple anaerobic elemental sulfur oxidation with ferric iron reduction.

    Science.gov (United States)

    Kucera, Jiri; Sedo, Ondrej; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

    2016-09-01

    In extremely acidic environments, ferric iron can be a thermodynamically favorable electron acceptor during elemental sulfur oxidation by some Acidithiobacillus spp. under anoxic conditions. Quantitative 2D-PAGE proteomic analysis of a resting cell suspension of a sulfur-grown Acidithiobacillus ferrooxidans CCM 4253 subculture that had lost its iron-reducing activity revealed 147 protein spots that were downregulated relative to an iron-reducing resting cell suspension of the antecedent sulfur-oxidizing culture and 111 that were upregulated. Tandem mass spectrometric analysis of strongly downregulated spots identified several physiologically important proteins that apparently play roles in ferrous iron oxidation, including the outer membrane cytochrome Cyc2 and rusticyanin. Other strongly repressed proteins were associated with sulfur metabolism, including heterodisulfide reductase, thiosulfate:quinone oxidoreductase and sulfide:quinone reductase. Transcript-level analyses revealed additional downregulation of other respiratory genes. Components of the iron-oxidizing system thus apparently play central roles in anaerobic sulfur oxidation coupled with ferric iron reduction in the studied microbial strain. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. Reduction of arsenic content in a complex galena concentrate by Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    López Alejandro

    2004-10-01

    Full Text Available Abstract Background Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxidans. There are a few studies about the benefit of metals of low value through bioleaching. From all of these, there are almost no studies dealing with complex minerals containing arsenopyrite (FeAsS. Reduction and/or elimination of arsenic in these ores increase their value and allows the exploitation of a vast variety of minerals that today are being underexploited. Results Arsenopyrite was totally oxidized. The sum of arsenic remaining in solution and removed by sampling represents from 22 to 33% in weight (yield of the original content in the mineral. The rest of the biooxidized arsenic form amorphous compounds that precipitate. Galena (PbS was totally oxidized too, anglesite (PbSO4 formed is virtually insoluble and remains in the solids. The influence of seven factors in a batch process was studied. The maximum rate of arsenic dissolution in the concentrate was found using the following levels of factors: small surface area of particle exposure, low pulp density, injecting air and adding 9 K medium to the system. It was also found that ferric chloride and carbon dioxide decreased the arsenic dissolution rate. Bioleaching kinetic data of arsenic solubilization were used to estimate the dilution rate for a continuous culture. Calculated dilution rates were relatively small (0.088–0.103 day-1. Conclusion Proper conditions of solubilization of arsenic during bioleaching are key features to improve the percentage (22 to 33% in weight of arsenic removal. Further studies are needed to determine other factors that influence specifically the

  18. Biosynthesis of schwertmannite by Acidithiobacillus ferrooxidans cell suspensions under different pH condition

    Energy Technology Data Exchange (ETDEWEB)

    Liao Yuehua [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhou Lixiang [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)], E-mail: lxzhou@njau.edu.cn; Liang Jianru; Xiong Huixin [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2009-01-01

    Oxidation of FeSO{sub 4} solution with initial pH in the range of 1.40-3.51 by Acidithiobacillus ferrooxidans LX5 cell at 26 deg. C and subsequent precipitation of resulting Fe(III) were investigated in the present study. Results showed that the oxidation rate of Fe(II) was around 1.2-3.9 mmol l{sup -1} h{sup -1}. X-ray diffraction (XRD) indicated that the formed precipitates were composed of natrojarosite with schwertmannite when the initial pH was 3.51, while only schwertmannite was produced when initial pH was in the range of 1.60-3.44 and no precipitate occurred when initial pH {<=} 1.40. Scanning electron microscope (SEM) analyses showed that precipitates formed in solution with initial pH 3.51 were spherical particles of about 0.4 {mu}m in diameter and had a smooth surface, whereas precipitates in solution with initial pH {<=} 3.44 were spherical particles of approximately 1.0 {mu}m in diameter, having specific sea-urchin morphology. Specific surface area of the precipitates varied from 3.42 to 23.45 m{sup 2} g{sup -1}. X-ray fluorescence analyses revealed that schwertmannite formed in solution with initial pH in the range of 2.00-3.44 had similar elemental composition and could be expressed as Fe{sub 8}O{sub 8}(OH){sub 4.42}(SO{sub 4}){sub 1.79,} whereas Fe{sub 8}O{sub 8}(OH){sub 4.36}(SO{sub 4}){sub 1.82} and Fe{sub 8}O{sub 8}(OH){sub 4.29}(SO{sub 4}){sub 1.86} as its chemical formula when the initial pH was 1.80 and 1.60, respectively.

  19. Flotacion diferencial de sulfuros en celda Hallimond, mediada por Acidithiobacillus ferrooxidans

    National Research Council Canada - National Science Library

    Mejia Restrepo, Erica; Osorno Bedoya, Laura; Ospina Correa, Juan David; Marquez Godoy, Marco Antonio

    2011-01-01

    Se investigo el efecto del pre-acondicionamiento oxidante con Acidithio-bacillus ferroxidans, precedido de un proceso de flotacion diferencial en celda Hallimond, para mezclas pirita-galena, pirita...

  20. Impact of bioavailable Pb2+ on Fe2+ oxidation in the presence of a mixed culture of Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Wang, H.; Yang, X.; Gong, L.; Jiang, Z.

    2009-12-01

    Numerous investigations were conducted on the effects of a variety of metals, including As, Cu, Zn, Cr on the growth of Acidithiobacillus ferrooxidans (an iron oxidizer and indigenous to acidic environment) and Fe2+ oxidation. However, less work was reported concerning the Pb2+ effect due to its quick precipitation as anglesite in SO42--rich solutions. The reported inhibiting concentrations of Pb2+ varied greatly on the oxidizing rate of ferrous in the presence of A. ferrooxidans, and the reasons remain unclear. Comparative studies were conducted between chemical and microbial oxidation of ferrous by a mixed culture of A. ferrooxidans in the presence of different concentration of Pb2+. Eh, pH and Fe2+ concentration were monitored periodically and the final precipitates were analyzed by X-ray diffraction (XRD), scanning electronic microscopy (SEM), and SEM-EDAX (Energy-dispersive X-ray spectroscopy). To check the impact of bioavailable Pb2+ on Fe2+ oxidation, initial precipitation was removed before the microbial inoculation. Our data showed that Pb2+ will exert a remarkable inhibition on microbial oxidation of ferrous when initial Pb2+ concentration reached as high as 5 g/L. However, the bioavailable Pb2+ in this case should be much lower than 5 g/L in the solution due to the precipitation of anglesite (The absolute concentration was under analysis). The threshold of Pb2+ concentrations to inhibit the microbial oxidation varies among the previous studies. This might result from the different microbial strains used or the mistaking of initial concentration as the substantial concentration of bioavailable Pb2+ after precipitation as anglesite. In contrast, Pb2+ does not show any obvious influence on chemical oxidation of ferrous. XRD spectrum of the final precipitates showed that anglesite was the only solid phase detected in chemical systems, while pure jarosite was found in the microbial systems. No lead was detected in jarosite by SEM-EDAX, inferring that Pb was

  1. Increases of ferrous iron oxidation activity and arsenic stressed cell growth by overexpression of Cyc2 in Acidithiobacillus ferrooxidans ATCC19859.

    Science.gov (United States)

    Liu, Wei; Lin, Jianqun; Pang, Xin; Mi, Shuang; Cui, Shuang; Lin, Jianqiang

    2013-01-01

    Acidithiobacillus ferrooxidans plays an important role in bioleaching in reproducing the mineral oxidant of ferric iron (Fe(3+) ) by oxidization of ferrous iron (Fe(2+) ). The high-molecular-weight c-type cytochrome Cyc2 that is located in the external membrane is postulated as the first electron carrier in the Fe(2+) oxidation respiratory pathway of A. ferrooxidans. To increase ferrous iron oxidation activity, a recombinant plasmid pTCYC2 containing cyc2 gene under the control of Ptac promoter was constructed and transferred into A. ferrooxidans ATCC19859. The transcriptional level of cyc2 gene was increased by 2.63-fold and Cyc2 protein expression was observed in the recombinant strain compared with the control. The ferrous iron oxidation activity and the arsenic stressed cell growth of the recombinant strain were also elevated. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  2. Estudo da oxidação dos sulfetos sintéticos molibdenita (MoS2 e covelita (CuS por Acidithiobacillus ferrooxidans via respirometria celular Oxidation study of the synthetic sulfides molybdenite (MoS2 and covellite (CuS by Acidithiobacillus ferrooxidans using respirometric experiments

    Directory of Open Access Journals (Sweden)

    Wilmo E. Francisco Junior

    2009-01-01

    Full Text Available This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry-bacterial attack, what is influenced by its electronic structures. Besides, experiments conducted in the presence of Fe3+ did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations.

  3. "Isolation, identification, characterization and polymetallic concentrate leaching studies of tryptic soy- and peptone-resistant thermotolerant Acidithiobacillus ferrooxidans SRDSM2".

    Science.gov (United States)

    Patel, Mitesh J; Tipre, Devayani R; Dave, Shailesh R

    2011-01-01

    Acidithiobacillus ferrooxidans strain SRDSM2 was isolated from silica containing soil sample collected at a Rajpardi lignite mine. The strain responded to the addition of 0.5 g/L peptone and 1.0 g/L tryptone soya broth in the ferrous sulphate tryptone soya broth (ITSB) medium with 35.3% and 29.6% increase in iron oxidation rate (IOR), but decrease in the IOR at higher peptone or tryptone soya broth levels. The presence of 4 mM of zinc as zinc sulphate in the medium increased the IOR by 24.4%. Forty percent of the inoculated cells survived even after exposure at 80 °C for 120 min and showed 30% ferrous iron oxidation. The Vmax and Ks for iron oxidation by the isolate were 344.82 mg/L/h and 32.25 g/L respectively. The isolate was able to oxidized ferrous iron even in presence of 4.06 M ionic strength of medium and leached>85% copper and zinc from the polymetallic concentrate. Thus, this isolate can be used for bioextraction of metals from polymetallic concentrate. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. The quinone-binding site of Acidithiobacillus ferrooxidans sulfide: quinone oxidoreductase controls both sulfide oxidation and quinone reduction.

    Science.gov (United States)

    Zhang, Yanfei; Qadri, Ali; Weiner, Joel H

    2016-04-01

    Sulfide:quinone oxidoreductase (SQR) is a peripheral membrane enzyme that catalyzes the oxidation of sulfide and the reduction of ubiquinone. Ubiquinone binds to a conserved hydrophobic domain and shuttles electrons from a noncovalent flavin adenine dinucleotide cofactor to the membrane-bound quinone pool. Utilizing the structure of decylubiquinone bound to Acidithiobacillus ferrooxidans SQR, we combined site-directed mutagenesis and kinetic approaches to analyze quinone binding. SQR can reduce both benzoquinones and naphthoquinones. The alkyl side-chain of ubiquinone derivatives enhances binding to SQR but limits the enzyme turnover. Pentachlorophenol and 2-n-heptyl-4-hydroxyquinoline-N-oxide are potent inhibitors of SQR with apparent inhibition constants (Ki) of 0.46 μmol·L(-1) and 0.58 μmol·L(-1), respectively. The highly conserved amino acids surrounding the quinone binding site play an important role in quinone reduction. The phenyl side-chains of Phe357 and Phe391 sandwich the benzoquinone head group and are critical for quinone binding. Importantly, conserved amino acids that define the ubiquinone-binding site also play an important role in sulfide oxidation/flavin reduction.

  5. Synchrotron radiation based STXM analysis and micro-XRF mapping of differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on Fe(2+) and S(0).

    Science.gov (United States)

    Xia, Jin-Lan; Liu, Hong-Chang; Nie, Zhen-Yuan; Peng, An-An; Zhen, Xiang-Jun; Yang, Yun; Zhang, Xiu-Li

    2013-09-01

    The differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on substrates Fe(2+) and S(0) was investigated by using synchrotron radiation based scanning transmission X-ray microscopy (STXM) imaging and microbeam X-ray fluorescence (μ-XRF) mapping. The extracellular thiol groups (SH) were first alkylated by iodoacetic acid forming Protein-SCH2COOH and then the P-SCH2COOH was marked by calcium ions forming P-SCH2COOCa. The STXM imaging and μ-XRF mapping of SH were based on analysis of SCH2COO-bonded Ca(2+). The results indicated that the thiol group content of A. ferrooxidans grown on S(0) is 3.88 times to that on Fe(2+). Combined with selective labeling of SH by Ca(2+), the STXM imaging and μ-XRF mapping provided an in situ and rapid analysis of differential expression of extracellular thiol groups. © 2013.

  6. Oxidation of dibenzothiophene as a model substrate for the removal of organic sulphur from fossil fuels by iron(III ions generated from pyrite by Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    VLADIMIR P. BESKOSKI

    2007-06-01

    Full Text Available Within this paper a new idea for the removal of organically bonded sulphur from fossil fuels is discussed. Dibenzothiophene (DBT was used as a model compound of organicmolecules containing sulphur. This form of (biodesulphurization was performed by an indirect mechanism in which iron(III ions generated from pyrite by Acidithiobacillus ferrooxidans performed the abiotic oxidation. The obtained reaction products, dibenzothiopene sulfoxide and dibenzothiophene sulfone, are more soluble in water than the basic substrate and the obtained results confirmed the basic hypothesis and give the posibility of continuing the experiments related to application of this (biodesulphurization process.

  7. The Multicenter Aerobic Iron Respiratory Chain of Acidithiobacillus ferrooxidans Functions as an Ensemble with a Single Macroscopic Rate Constant.

    Science.gov (United States)

    Li, Ting-Feng; Painter, Richard G; Ban, Bhupal; Blake, Robert C

    2015-07-24

    Electron transfer reactions among three prominent colored proteins in intact cells of Acidithiobacillus ferrooxidans were monitored using an integrating cavity absorption meter that permitted the acquisition of accurate absorbance data in suspensions of cells that scattered light. The concentrations of proteins in the periplasmic space were estimated to be 350 and 25 mg/ml for rusticyanin and cytochrome c, respectively; cytochrome a was present as one molecule for every 91 nm(2) in the cytoplasmic membrane. All three proteins were rapidly reduced to the same relative extent when suspensions of live bacteria were mixed with different concentrations of ferrous ions at pH 1.5. The subsequent molecular oxygen-dependent oxidation of the multicenter respiratory chain occurred with a single macroscopic rate constant, regardless of the proteins' in vitro redox potentials or their putative positions in the aerobic iron respiratory chain. The crowded electron transport proteins in the periplasm of the organism constituted an electron conductive medium where the network of protein interactions functioned in a concerted fashion as a single ensemble with a standard reduction potential of 650 mV. The appearance of product ferric ions was correlated with the reduction levels of the periplasmic electron transfer proteins; the limiting first-order catalytic rate constant for aerobic respiration on iron was 7,400 s(-1). The ability to conduct direct spectrophotometric studies under noninvasive physiological conditions represents a new and powerful approach to examine the extent and rates of biological events in situ without disrupting the complexity of the live cellular environment. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. The Multicenter Aerobic Iron Respiratory Chain of Acidithiobacillus ferrooxidans Functions as an Ensemble with a Single Macroscopic Rate Constant*

    Science.gov (United States)

    Li, Ting-Feng; Painter, Richard G.; Ban, Bhupal; Blake, Robert C.

    2015-01-01

    Electron transfer reactions among three prominent colored proteins in intact cells of Acidithiobacillus ferrooxidans were monitored using an integrating cavity absorption meter that permitted the acquisition of accurate absorbance data in suspensions of cells that scattered light. The concentrations of proteins in the periplasmic space were estimated to be 350 and 25 mg/ml for rusticyanin and cytochrome c, respectively; cytochrome a was present as one molecule for every 91 nm2 in the cytoplasmic membrane. All three proteins were rapidly reduced to the same relative extent when suspensions of live bacteria were mixed with different concentrations of ferrous ions at pH 1.5. The subsequent molecular oxygen-dependent oxidation of the multicenter respiratory chain occurred with a single macroscopic rate constant, regardless of the proteins' in vitro redox potentials or their putative positions in the aerobic iron respiratory chain. The crowded electron transport proteins in the periplasm of the organism constituted an electron conductive medium where the network of protein interactions functioned in a concerted fashion as a single ensemble with a standard reduction potential of 650 mV. The appearance of product ferric ions was correlated with the reduction levels of the periplasmic electron transfer proteins; the limiting first-order catalytic rate constant for aerobic respiration on iron was 7,400 s−1. The ability to conduct direct spectrophotometric studies under noninvasive physiological conditions represents a new and powerful approach to examine the extent and rates of biological events in situ without disrupting the complexity of the live cellular environment. PMID:26041781

  9. Interaction of Acidithiobacillus ferrooxidans, Rhizobium phaseoli and Rhodotorula sp. in bioleaching process based on Lotka–Volterra model

    Directory of Open Access Journals (Sweden)

    Xuecheng Zheng

    2016-07-01

    Conclusion: The relationship among microorganisms during leaching could be described appropriately by Lotka–Volterra model between the initial and peak values. The relationship of A. ferrooxidans and R. phaseoli could be considered as mutualism, whereas, the relationship of A. ferrooxidans and R. phaseoli could be considered as commensalism.

  10. Evaluación de oxidación bacteriana de sulfuros con Acidithiobacillus ferrooxidans mediante pruebas de FTIR y difracción de rayos X Evaluating Acidithiobacillus ferrooxidans bacterial oxidation of sulphur compounds using FTIR and X-ray diffraction assays

    OpenAIRE

    Ruiz Orlando; Lemehsko Victor; Montoya Olga I.; Márquez Marco A.; Muñoz Alexandra

    2003-01-01

    Una cepa bacteriana nativa con capacidad de oxidar hierro ferroso y compuestos del azufre fue aislada a partir de efluentes y material de la mina de oro La Maruja, en el municipio de Marmato (Caldas), la cual fue identificada bioquímicamente como Acidithiobacillus ferrooxidans. Esta cepa fue evaluada en su capacidad de oxidar concentra­dos de sulfuros metálicos a dos diferentes concentraciones de pulpa y dos tamaños de partícula. Después de 15 días de biooxidación de los sulfuros se observó q...

  11. Investigação da rota biohidrometalúrgica com Acidithiobacillus ferrooxidans/thiooxidans para recuperação do cobalto de baterias de íons lítio descartadas

    OpenAIRE

    Santana, Laiane Kalita de

    2016-01-01

    A reciclagem de metais a partir de fontes secundárias pode ser vantajosa ao meio ambiente. Dentre os metais de interesse temos o cobalto, metal utilizado para diversas finalidades. Com relação às fontes secundárias de cobalto, as baterias de íons lítio podem ser consideradas, visto que contem um óxido de cobalto em sua composição (LiCoO2). Dessa forma, o objetivo do trabalho foi utilizar as linhagens de Acidithiobacillus ferrooxidans e Acidithiobacillus thiooxidans para biolixi...

  12. Oxidation study of the synthetic sulfides molybdenite (MoS{sub 2}) and covellite (CuS) by acidithiobacillus ferrooxidants using respirometric experiments; Estudo da oxidacao dos sulfetos sinteticos molibdenita (MoS2) e covelita (CuS) por Acidithiobacillus ferrooxidans via respirometria celular

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Junior, Wilmo E. [Universidade Federal de Rondonia (UFRO), Porto Velho, RO (Brazil). Dept. de Quimica; Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica], e-mail: wilmojr@bol.com.br; Bevilaqua, Denise; Garcia Junior, Oswaldo [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica

    2009-07-01

    This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry-bacterial attack, what is influenced by its electronic structures. Besides, experiments conducted in the presence of Fe{sup 3+} did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations. (author)

  13. Effect of calcium oxide on the efficiency of ferrous ion oxidation and total iron precipitation during ferrous ion oxidation in simulated acid mine drainage treatment with inoculation of Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Liu, Fenwu; Zhou, Jun; Jin, Tongjun; Zhang, Shasha; Liu, Lanlan

    2016-01-01

    Calcium oxide was added into ferrous ion oxidation system in the presence of Acidithiobacillus ferrooxidans at concentrations of 0-4.00 g/L. The pH, ferrous ion oxidation efficiency, total iron precipitation efficiency, and phase of the solid minerals harvested from different treatments were investigated during the ferrous ion oxidation process. In control check (CK) system, pH of the solution decreased from 2.81 to 2.25 when ferrous ions achieved complete oxidation after 72 h of Acidithiobacillus ferrooxidans incubation without the addition of calcium oxide, and total iron precipitation efficiency reached 20.2%. Efficiency of ferrous ion oxidation and total iron precipitation was significantly improved when the amount of calcium oxide added was ≤1.33 g/L, and the minerals harvested from systems were mainly a mixture of jarosite and schwertmannite. For example, the ferrous ion oxidation efficiency reached 100% at 60 h and total iron precipitation efficiency was increased to 32.1% at 72 h when 1.33 g/L of calcium oxide was added. However, ferrous ion oxidation and total iron precipitation for jarosite and schwertmannite formation were inhibited if the amount of calcium oxide added was above 2.67 g/L, and large amounts of calcium sulfate dihydrate were generated in systems.

  14. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

    Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

  15. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Danielle Moinier

    2017-07-01

    Full Text Available The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs. In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s was (were located upstream from the −35 (or −24 box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed.

  16. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Moinier, Danielle; Byrne, Deborah; Amouric, Agnès; Bonnefoy, Violaine

    2017-01-01

    The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs). In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA) on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s) was (were) located upstream from the -35 (or -24) box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed.

  17. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Moinier, Danielle; Byrne, Deborah; Amouric, Agnès; Bonnefoy, Violaine

    2017-01-01

    The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs). In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA) on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s) was (were) located upstream from the −35 (or −24) box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed. PMID:28747899

  18. Insights into the pathways of iron- and sulfur-oxidation, and biofilm formation from the chemolithotrophic acidophile Acidithiobacillus ferrivorans CF27.

    Science.gov (United States)

    Talla, Emmanuel; Hedrich, Sabrina; Mangenot, Sophie; Ji, Boyang; Johnson, D Barrie; Barbe, Valérie; Bonnefoy, Violaine

    2014-11-01

    The iron-oxidizing acidithiobacilli cluster into at least four groups, three of which (Acidithiobacillus ferrooxidans, Acidithiobacillus ferridurans and Acidithiobacillus ferrivorans) have been designated as separate species. While these have many physiological traits in common, they differ in some phenotypic characteristics including motility, and pH and temperature minima. In contrast to At. ferrooxidans and At. ferridurans, all At. ferrivorans strains analysed to date possess the iro gene (encoding an iron oxidase) and, with the exception of strain CF27, the rusB gene encoding an iso-rusticyanin whose exact function is uncertain. Strain CF27 differs from other acidithiobacilli by its marked propensity to form macroscopic biofilms in liquid media. To identify the genetic determinants responsible for the oxidation of ferrous iron and sulfur and for the formation of extracellular polymeric substances, the genome of At. ferrivorans CF27 strain was sequenced and comparative genomic studies carried out with other Acidithiobacillus spp.. Genetic disparities were detected that indicate possible differences in ferrous iron and reduced inorganic sulfur compounds oxidation pathways among iron-oxidizing acidithiobacilli. In addition, strain CF27 is the only sequenced Acidithiobacillus spp. to possess genes involved in the biosynthesis of fucose, a sugar known to confer high thickening and flocculating properties to extracellular polymeric substances. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  19. Biogeography of sulfur-oxidizing Acidithiobacillus populations in extremely acidic cave biofilms.

    Science.gov (United States)

    Jones, Daniel S; Schaperdoth, Irene; Macalady, Jennifer L

    2016-12-01

    Extremely acidic (pH 0-1.5) Acidithiobacillus-dominated biofilms known as snottites are found in sulfide-rich caves around the world. Given the extreme geochemistry and subsurface location of the biofilms, we hypothesized that snottite Acidithiobacillus populations would be genetically isolated. We therefore investigated biogeographic relationships among snottite Acidithiobacillus spp. separated by geographic distances ranging from meters to 1000s of kilometers. We determined genetic relationships among the populations using techniques with three levels of resolution: (i) 16S rRNA gene sequencing, (ii) 16S-23S intergenic transcribed spacer (ITS) region sequencing and (iii) multi-locus sequencing typing (MLST). We also used metagenomics to compare functional gene characteristics of select populations. Based on 16S rRNA genes, snottites in Italy and Mexico are dominated by different sulfur-oxidizing Acidithiobacillus spp. Based on ITS sequences, Acidithiobacillus thiooxidans strains from different cave systems in Italy are genetically distinct. Based on MLST of isolates from Italy, genetic distance is positively correlated with geographic distance both among and within caves. However, metagenomics revealed that At. thiooxidans populations from different cave systems in Italy have different sulfur oxidation pathways and potentially other significant differences in metabolic capabilities. In light of those genomic differences, we argue that the observed correlation between genetic and geographic distance among snottite Acidithiobacillus populations is partially explained by an evolutionary model in which separate cave systems were stochastically colonized by different ancestral surface populations, which then continued to diverge and adapt in situ.

  20. Physiological and comparative genomic analysis of Acidithiobacillus ferrivorans PQ33 provides psychrotolerant fitness evidence for oxidation at low temperature.

    Science.gov (United States)

    Ccorahua-Santo, Robert; Eca, Anika; Abanto, Michel; Guerra, Gregory; Ramírez, Pablo

    2017-06-01

    Friendly environmental hydrometallurgy at low temperatures is principally promoted by Acidithiobacillus ferrivorans. Until recently, the synergy between cold tolerance and the molecular mechanism of ferrous iron (Fe2+) oxidation was unknown. In the present paper, we conducted a physiological and comparative genomics analysis of the new strain A. ferrivorans PQ33 to elucidate the oxidation mechanism at low temperatures, with emphasis placed on trehalose and the Rus operon. PQ33 exhibited a doubling time of 66.6 h in Fe2+ at pH 1.6 and 63.6 h in CuS at 5 °C. Genomic island (GI) identification and comparative genome analysis were performed with four available genomes of Acidithiobacillus sp. The genome comprised 3,298,172 bp and 56.55% GC content. In contrast to ATCC Acidithiobacillus ferrooxidans strains, the genome of A. ferrivorans PQ33 harbors one GI, which contains a RusB gene. Moreover, five genes of peptidyl-prolyl cis-trans isomerase (PPIases) were observed. Furthermore, comparative analysis of the trehalose operon suggested the presence of a horizontal transfer event. In addition, comparison of rusticyanin proteins revealed that RusB has better intrinsic flexibility than RusA. This comparison suggests psychrotolerant fitness and supports the genetic canalization of A. ferrivorans PQ33 for oxidation at low temperature. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  1. Optimal sulphuric acid production using Acidithiobacillus caldus ...

    African Journals Online (AJOL)

    An optimised bioprocess was designed for the optimal production of sulphuric acid for application in an isotope recovery ion-exchange process. Firstly, the production of sulphuric acid (H2SO4) was optimised in aerated batch bioreactors using Acidithiobacillus caldus (DSM 8584) using elemental sulphur, achieving H2SO4 ...

  2. "Use of acidophilic bacteria of the genus Acidithiobacillus to biosynthesize CdS fluorescent nanoparticles (quantum dots) with high tolerance to acidic pH".

    Science.gov (United States)

    Ulloa, G; Collao, B; Araneda, M; Escobar, B; Álvarez, S; Bravo, D; Pérez-Donoso, J M

    2016-12-01

    The use of bacterial cells to produce fluorescent semiconductor nanoparticles (quantum dots, QDs) represents a green alternative with promising economic potential. In the present work, we report for the first time the biosynthesis of CdS QDs by acidophilic bacteria of the Acidithiobacillus genus. CdS QDs were obtained by exposing A. ferrooxidans, A. thiooxidans and A. caldus cells to sublethal Cd(2+) concentrations in the presence of cysteine and glutathione. The fluorescence of cadmium-exposed cells moves from green to red with incubation time, a characteristic property of QDs associated with nanocrystals growth. Biosynthesized nanoparticles (NPs) display an absorption peak at 360nm and a broad emission spectra between 450 and 650nm when excited at 370nm, both characteristic of CdS QDs. Average sizes of 6 and 10nm were determined for green and red NPs, respectively. The importance of cysteine and glutathione on QDs biosynthesis in Acidithiobacillus was related with the generation of H2S. Interestingly, QDs produced by acidophilic bacteria display high tolerance to acidic pH. Absorbance and fluorescence properties of QDs was not affected at pH 2.0, a condition that totally inhibits the fluorescence of QDs produced chemically or biosynthesized by mesophilic bacteria (stable until pH 4.5-5.0). Results presented here constitute the first report of the generation of QDs with improved properties by using extremophile microorganisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Biooxidacion de sulfuros mediante cepas nativas de acidofilos compatibles con Acidithiobacillus ferrooxidans y thiooxidans, mina de oro El Zancudo

    National Research Council Canada - National Science Library

    H. Ossa, Dianna M; Marquez G., Marco A

    2005-01-01

    ... y potencial redox realizadas por un tiempo de 25 dias, demuestran que hubo una actividad de oxidacion eficiente y se llego a valores de pH de 1,4 y potencial redox de 600 mV, ademas de encontrarse en solucion niveles altos de alrededor de 20 g/L de As y 60 g/L de Fe. Por los analisis de DRX, FTIR y SEM/EDX, se evidencia la presencia de productos propios ...

  4. Biosynthesis of bifunctional iron oxyhydrosulfate by Acidithiobacillus ferroxidans and their application to coagulation and adsorption.

    Science.gov (United States)

    Gan, Min; Song, Zibo; Jie, Shiqi; Zhu, Jianyu; Zhu, Yaowu; Liu, Xinxing

    2016-02-01

    Coagulation and adsorption are important environmental technologies, which were widely applied in water treatment. In this study, a type of villous iron oxyhydrosulfate with low crystallinity, high content iron, sulfate and hydroxyl was synthesized by Acidithiobacillus ferrooxidans, which possessed coagulation and heavy metal adsorption ability simultaneously. The results showed that the Cu(II) adsorption capacity increased within a small range over the pH range of 3.0-5.0 but increased evidently over the range of 6.0-8.0. The maximal Cu(II) adsorption capacity of sample Af and Gf reached 50.97 and 46.08mg/g respectively. The optimum pH for Cr(VI) adsorption was 6.0, and the maximal adsorption capacity reached 51.32 and 59.57mg/g. The Langmuir isotherm can better describe the adsorption behavior of Cr(VI). Coagulation performance of the iron oxyhydrosulfate (Sh) has been significantly enhanced by polysilicic acid (PSA), which was mainly determined by PSA/Sh ratio, pH and coagulant dosage. Coagulation efficiency maintained approximately at 98% when the PSA/Sh ratio ranged from 0.4/0.1 to 1.0/0.1. Polysilicic acid worked efficiently in wide pH range extending, from 2 to 3.5. Coagulation performance improved significantly with the increasing of the coagulant dosage at lower dosage range, while, at higher dosage range, the improvement was not evident even with more coagulant addition. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Complete genome sequence of Acidimicrobium ferrooxidans type strain (ICPT)

    Energy Technology Data Exchange (ETDEWEB)

    Clum, Alicia; Nolan, Matt; Lang, Elke; Glavina Del Rio, Tijana; Tice, Hope; Copeland, Alex; Cheng, Jan-Fang; Lucas, Susan; Chen, Feng; Bruce, David; Goodwin, Lynne; Pitluck, Sam; Ivanova, Natalia; Mavrommatis, Konstantinos; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Goker, Markus; Spring, Stefan; Land, Miriam; Hauser, Loren; Chang, Yun-Juan; Jefferies, Cynthia C.; Chain, Patrick; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C.; Klenk, Hans-Peter; Lapidus, Alla

    2009-05-20

    Acidimicrobium ferrooxidans (Clark and Norris 1996) is the sole and type species of the genus, which until recently was the only genus within the actinobacterial family Acidimicrobiaceae and in the order Acidomicrobiales. Rapid oxidation of iron pyrite during autotrophic growth in the absence of an enhanced CO2 concentration is characteristic for A. ferrooxidans. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of the order Acidomicrobiales, and the 2,158,157 bp long single replicon genome with its 2038 protein coding and 54 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  6. Sulfur Oxygenase Reductase (Sor in the Moderately Thermoacidophilic Leaching Bacteria: Studies in Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Claudia Janosch

    2015-10-01

    Full Text Available The sulfur oxygenase reductase (Sor catalyzes the oxygen dependent disproportionation of elemental sulfur, producing sulfite, thiosulfate and sulfide. Being considered an “archaeal like” enzyme, it is also encoded in the genomes of some acidophilic leaching bacteria such as Acidithiobacillus caldus, Acidithiobacillus thiooxidans, Acidithiobacillus ferrivorans and Sulfobacillus thermosulfidooxidans, among others. We measured Sor activity in crude extracts from Sb. thermosulfidooxidans DSM 9293T. The optimum temperature for its oxygenase activity was achieved at 75 °C, confirming the “thermophilic” nature of this enzyme. Additionally, a search for genes probably involved in sulfur metabolism in the genome sequence of Sb. thermosulfidooxidans DSM 9293T was done. Interestingly, no sox genes were found. Two sor genes, a complete heterodisulfidereductase (hdr gene cluster, three tetrathionate hydrolase (tth genes, three sulfide quinonereductase (sqr, as well as the doxD component of a thiosulfate quinonereductase (tqo were found. Seven At. caldus strains were tested for Sor activity, which was not detected in any of them. We provide evidence that an earlier reported Sor activity from At. caldus S1 and S2 strains most likely was due to the presence of a Sulfobacillus contaminant.

  7. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus "Ferrovum".

    Directory of Open Access Journals (Sweden)

    Sophie R Ullrich

    Full Text Available Members of the genus "Ferrovum" are ubiquitously distributed in acid mine drainage (AMD waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain "Ferrovum myxofaciens" P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus "Ferrovum" is extremely scarce.In order to access the wider genetic pool of the genus "Ferrovum" we sequenced the genome of a "Ferrovum"-containing mixed culture and successfully assembled the almost complete genome sequence of the novel "Ferrovum" strain JA12.The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct "Ferrovum" species. "Ferrovum" strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that "Ferrovum" strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively.The potential utilisation of urea by "Ferrovum" strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs "Ferrovum" strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin and Acidithiobacillus ferrivorans (iron oxidase indicates the existence of a modified pathway in "Ferrovum" strain JA12

  8. Biological effect of Acidithiobacillus thiooxidans on some potentially toxic elements during alteration of SON 68 nuclear glass

    Science.gov (United States)

    Bachelet, M.; Crovisier, J. L.; Stille, P.; Vuilleumier, S.; Geoffroy, V.

    2009-04-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH, with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 m french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25degC. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, trace and ultra-trace elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 m under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials are found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium as tracer, showed that the progressive formation of a biofilm on the surface of glass has a protective effect against its alteration. Uranium and rare earth elements (REE) are efficiently trapped in the biogenic compartment of the system (exopolysaccharides + bacterial cells). Besides, the ratio

  9. Energy Transduction by Anaerobic Ferric Iron Respiration in Thiobacillus-Ferrooxidans

    OpenAIRE

    Pronk, J T; Liem, K.; de Bos, P; Kuenen, J G

    1991-01-01

    Formate-grown cells of the obligately chemolithoautotrophic acidophile Thiobacillus ferrooxidans were capable of formate- and elemental sulfur-dependent reduction of ferric iron under anaerobic conditions. Under aerobic conditions, both oxygen and ferric iron could be simultaneously used as electron acceptors. To investigate whether anaerobic ferric iron respiration by T. ferrooxidans is an energy-transducing process, uptake of amino acids was studied. Glycine uptake by starved cells did not ...

  10. Microbiological leaching of a chalcopyrite concentrate by Thiobacillus ferrooxidans.

    Science.gov (United States)

    Sakaguchi, H; Silver, M

    1976-08-01

    The microbiological leaching of a chalcopyrite concentrate has been investigated using a pure strain of Thiobacillus ferrooxidans. The optimum leaching conditions regarding pH, temperature, and pulp density were found to be 2.3, 35 degrees C, and 22% respectively. The energy of activation was calculated to be 16.7 kcal/mol. During these experiments the maximum rate of copper dissolution was about 215 mg/liters/hr and the final copper concentration was as high as 55 g/liter. This latter value is in the range of copper concentrations which may be used for direct electrorecovery of copper. Jarosite formation was observed during the leaching of the chalcopyrite concentrate. When the leach residue was reground to expose new substrate surface, subsequent leaching resulted in copper extractions up to about 80%. On the basis of this experimental work, a flow sheet has been proposed for commercial scale biohydrometallurgical treatment of high-grade chalcopyrite materials.

  11. Biodegradation of the french reference nuclear glass SON 68 by Acidithiobacillus thiooxidans : protective effect of the biofilm,U and REE retention

    Science.gov (United States)

    Bachelet, M.; Crovisier, J.; Stille, P.; Boutin, R.; Vuilleumier, S.; Geoffroy, V.

    2008-12-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 μm french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25°C. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, traces and ultra-traces elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 μm under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials can be found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium, molybdenum and caesium as tracers, showed that the biofilm has a protective effect against glass alteration. U and REE are efficiently trapped in the biogenic compartment of the system (exopolysaccharides (EPS) + bacterial cells). Biofilm analysis are in progress to determine whether these

  12. ESTUDIO DE LA PARTICIPACION DE PROTEINAS CODIFICADAS EN LOS GRUPOS GENETICOS DE DOXDA Y TETH EN LA OXIDACION DEL TIOSULFATO EN ACIDITHIOBACILLUS FERROOXIDANS ATCC 23270

    OpenAIRE

    BEARD BORQUEZ, SIMON RODRIGO

    2010-01-01

    El azufre es un macronutriente esencial para todos los seres vivos que forma parte de aminoácidos, cofactores y vitaminas. Algunos microorganismos son capaces de obtener su energía de la oxidación disasimilatoria del sulfuro, azufre elemental o tiosulfato, entre otros compuestos inorgánicos de azufre reducidos. En bacterias Gram-negativas se han descrito tres vías para la oxidación de compuestos de azufre: la vía del Paracoccus (PSO), la vía PSO ramificada y la vía del intermediar...

  13. Arsenic tolerance and bioleaching from realgar based on response surface methodology by Acidithiobacillus ferrooxidans isolated from Wudalianchi volcanic lake, northeast China

    Directory of Open Access Journals (Sweden)

    Lei Yan

    2017-01-01

    Conclusion: From this work we were successful in isolating an acidophilic, arsenic tolerant ferrous iron-oxidizing bacterium. The BBD-RSM analysis showed that maximum arsenic bioleaching rate obtained under optimum conditions, and the most effective factor for arsenic leaching was initial ferrous ion concentration. These revealed that BYQ-12 could be used for bioleaching of arsenic from arsenical minerals.

  14. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus “Ferrovum”

    Science.gov (United States)

    Ullrich, Sophie R.; Poehlein, Anja; Tischler, Judith S.; González, Carolina; Ossandon, Francisco J.; Daniel, Rolf; Holmes, David S.; Schlömann, Michael; Mühling, Martin

    2016-01-01

    Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus

  15. Estudos da biolixiviação de minerios de uranio por Thiobacillus ferrooxidans

    OpenAIRE

    Oswaldo Garcia Junior

    1989-01-01

    Resumo: O objetivo deste trabalho, foi desenvolver um programa de lixiviaç5o bacteriana de minérios de urânio, constituído por três pontos fundamentais: a) isolamento e purificação de Thiobacillus ferrooxidans (e também Thiobacillus thiooxidans); b) estudos fisiológicos de crescimento e de metabolismo respiratório da espécie T. ferrooxidans: c) lixiviaç5o do urânio de dois tipos distintos de minério pela ação do T. ferrooxidans, em escalas de laborat6rio, semi-piloto e piloto. Utilizando-se a...

  16. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid, and sodium lauryl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Onysko, S.J.; Kleinmann, R.L.P.; Erickson, P.M.

    1984-07-01

    Thiobacillus ferrooxidans promote indirect oxidation of pyrite through the catalysis of the oxidation of ferrous iron to ferric iron, which is an effective oxidant of pyrite. These bacteria also may catalyze direct oxidation of pyrite by oxygen. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous iron to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage microorganisms. In this study, benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

  17. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid and sodium lauryl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Onysko, S.J.

    1984-07-01

    Acid mine drainage is formed by the weathering or oxidation of pyritic material exposed during coal mining. The rate of pyritic material oxidation can be greatly accelerated by certain acidophilic bacteria such as Thiobacillus ferrooxidans which catalyse the oxidation of ferrous to ferric iron. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage micro-organisms. Sodium lauryl sulphate (SLS), an anionic surfactant has proved effective in this respect. Benzoic acid, sorbic acid and SLS at low concentrations, each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of T. ferrooxidans. The rate of chemical oxidation of ferrous iron in low pH, sterile, batch reactors was not substantially affected at the tested concentrations of any of the compounds.

  18. Impact of solvent extraction organics on adsorption and bioleaching of A. ferrooxidans and L. ferriphilum

    Science.gov (United States)

    Hualong, Yu; Xiaorong, Liu

    2017-04-01

    Copper solvent extraction entrained and dissoluted organics (SX organics) in the raffinate during SX operation can contaminated chalcopyrite ores and influence bioleaching efficiency by raffinate recycling. The adsorption and bioleaching of A. ferrooxidans and L. ferriphilum with contaminated ores were investigated. The results showed that, A. ferrooxidans and L. ferriphilum cells could adsorb quickly on minerals, the adsorption rate on contaminated ores were 83% and 60%, respectively, larger than on uncontaminated ores. However, in the bioleaching by the two kinds of acid bacterias, contaminated ores presented a lower bioleaching efficiency.

  19. Biofertilzers with natural phosphate, sulphur and Acidithiobacillus in a siol with low available-P

    Directory of Open Access Journals (Sweden)

    Stamford Newton Pereira

    2003-01-01

    Full Text Available The production of mineral fertilizers is a expensive process, since it requires high energy consumption, and cannot be produced by small farmers. Laboratory assays were conducted to produce P-biofertilizers from natural phosphate (B5, B10, B15, B20, applying sulphur at different rates (5; 10; 15 and 20% inoculated with Acidithiobacillus (S* and testing increasing periods of incubation. A greenhouse experiment was carried out to evaluate the effect of the biofertilizers in a soil with low available P (Typic Fragiudult from the "Zona da Mata" of Pernambuco State, grown with yam bean (Pachyrhizus erosus in two consecutive harvests. The treatments were: Natural Phosphate (NP; biofertilizers produced in laboratory (B5, B10, B15, B20 with sulphur and Acidithiobacillus (NP+S*; natural phosphate with sulphur (20% without Acidithiobacillus (NP+S; triple super phosphate (TSP and a control without phosphorus. Plants were inoculated with a mixture of rhizobia strains (NFB 747 and NFB 748 or did not receive rhizobia inoculation. In bioassays pH and available P in the biofertilizers were analyzed. In the greenhouse experiment shoot dry matter, total N and total P in shoots, soil pH and available P were determined. Higher rates of available P were obtained in biofertilizers with sulphur and Acidithiobacillus (NP+S* and in triple super phosphate (TSP, and biofertilizers with sulphur and Acidithiobacillus (FN+S* and triple super phosphate (TSP increased plant parameters. Native rhizobia were as effective as the strains applied in inoculation. After the two harvests soil presented lower pH values and higher rates of available P when the biofertilizers B15 and B20 with sulphur and Acidithiobacillus were applied.

  20. Sudy of adsorption microbial cells T.Ferrooxidans sulphide-quartz ores at their gold-bearing fractionation

    Directory of Open Access Journals (Sweden)

    Tonkova N.V.

    2010-06-01

    Full Text Available It was determined the regularity of the Th. ferrooxidans M-l microbial cclls adsorbtions on ore's participles (size from 0,063 till 0,315 depended on sulfides, carbonates minerals and quartz contents.

  1. A kinetic study of the depyritization of oil shale HCl-kerogen concentrate by Thiobacillus ferrooxidans at different temperatures

    Directory of Open Access Journals (Sweden)

    OLGA CVETKOVIC

    2003-05-01

    Full Text Available The results of kinetic studies of bacterial depyritization of HCl-kerogen concentrate of Aleksinac (Serbia oil shale by the chemolithoautotrophic thionic bacteria Thiobacillus ferrooxidans under discontinuous laboratory conditions at various temperatures (0, 20, 28 and 37°C at a pH of ca. 1.5 are presented in this paper. Low pH prevents the occurrence of the precipitation of iron(III-ion hydrolysis products on the substrate particles and thereby reduces the process efficiency. Bacterial depyritization is developed as per kinetics of the first order. The activation energy which points to a successive mechanism of pyrite biooxidation, was computed from the Arrhenius plot. The biochemical kinetics indicators point to a high affinity of the bacteria toward pyrite but small values of Vmax, which are probably the result of decelerated metabolic processes due to the low pH value of the environment resp. the large difference of the pH between the external medium and the cell interior.

  2. Effect of Applied Potentials on the Activity and Growth of Thiobacillus ferrooxidans

    OpenAIRE

    Natarajan, KA

    1992-01-01

    The effect of applied DC potentials both in the positive and negative range, on the activity and growth of Thiobacillus ferrooxidans, is discussed. In general, application of positive potentials up to +1000 mV in an acid bioleaching medium was found to be detrimental to bacterial activity, while the impression of negative potentials enhanced both their activity and growth through electrochemical regeneration of ferrous ions and an increase in the biomass. Ferrous-ferric ratios in a bioleachin...

  3. Selective Inhibition of the Oxidation of Ferrous Iron or Sulfur in Thiobacillus ferrooxidans

    OpenAIRE

    Harahuc, Lesia; Lizama, Hector M.; Suzuki, Isamu

    2000-01-01

    The oxidation of either ferrous iron or sulfur by Thiobacillus ferrooxidans was selectively inhibited or controlled by various anions, inhibitors, and osmotic pressure. Iron oxidation was more sensitive than sulfur oxidation to inhibition by chloride, phosphate, and nitrate at low concentrations (below 0.1 M) and also to inhibition by azide and cyanide. Sulfur oxidation was more sensitive than iron oxidation to the inhibitory effect of high osmotic pressure. These differences were evident not...

  4. Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

    Science.gov (United States)

    Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

    1984-01-01

    Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. PMID:16346592

  5. Bacterial CS2 Hydrolases from Acidithiobacillus thiooxidans Strains Are Homologous to the Archaeal Catenane CS2 Hydrolase

    NARCIS (Netherlands)

    Smeulders, M.J.; Pol, A. van der; Venselaar, H.; Barends, T.R.; Hermans, J.; Jetten, M.S.M.; Camp, H.J.M. op den

    2013-01-01

    Carbon disulfide (CS2) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS2 is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO2) and hydrogen sulfide

  6. Potentiality of Acidithiobacillus thiooxidans in Microbial Solubilization of Phosphate Mine Tailings

    Directory of Open Access Journals (Sweden)

    S Dhakar

    2015-04-01

    Full Text Available This paper deals with the solubilization behavior of the tailings produced by the floatation of a complex low grade phosphate ore. The composition of the tailings was essentially dolomite (52.04% with minor amounts of phosphate, iron and aluminium oxides (10.4 and 0.5% respectively. The presence of these products created uncontrolled land pollution and severely affected groundwater. An initiative has been taken up for utilization of this waste to generate an eco-friendly product. First step towards this panorama is incorporation of suitable microorganisms for the biodegradation of this effluent. Sulphur oxidizing bacteria Acidithiobacillus thiooxidans produces sulphuric acid which neutralizes the dolomitic tailings and convert it into plant available forms. The solubilization activity was tested in sulphur medium with 5, 10, 15 and 20% concentration of tailings. The solubilization is graded on the basis of pH, Electrical conductivity (EC, soluble calcium and magnesium and soluble phosphate. The results from ex-situ experiments showed that the treatment with 15% tailings ended with highest solubilization. The values of pH, EC, soluble calcium and magnesium and soluble phosphate for this treatment were 4.92, 31.6 dS/m, 10.8 mL EDTA and 17.24 µg/mL respectively. Also, the results proved that sulphur oxidizing bacteria Acidithiobacillus thiooxidans is capable of solubilizing dolomitic tailings from the Jhamarkotra mines. Finally, an important factor taken into account was solubilization of residual phosphate along with dolomite in the tailings. This combined action affects the solubilization behaviour of the residue, which was also showed successfully with the assayed laboratory studies.

  7. Efeito da adição de nanopartículas na biolixiviação da calcopirita ('CU''FE''S IND.2') por Acidithiobacillus ferrooxidans LR

    OpenAIRE

    Silva, Daniel Rodrigues da [UNESP

    2011-01-01

    A biolixiviação (lixiviação bacteriana) é uma alternativa para a extração de metais presentes em sulfetos minerais empregando microorganismos. Dentre as principais vantagens da biohidrometalurgia em relação aos métodos convencionais podem ser destacadas a não-emissão de SO2 para a atmosfera, pequeno gasto com insumos, pois são produzidos pelos próprios microorganismos, baixa demanda energética e o tratamento de minérios contendo metais em baixo teor. Uma das espécies envolvidas na biolixiviaç...

  8. Agronomic effectiveness of biofertilizers with phosphate rock, sulphur and Acidithiobacillus for yam bean grown on a Brazilian tableland acidic soil.

    Science.gov (United States)

    Stamford, N P; Santos, P R; Santos, C E S; Freitas, A D S; Dias, S H L; Lira, M A

    2007-04-01

    Phosphate rocks have low available P and soluble P fertilizers have been preferably used in plant crop production, although economic and effective P sources are needed. Experiments were carried out on a Brazilian Typic Fragiudult soil with low available P to evaluate the agronomic effectiveness of phosphate rock (PR) compared with soluble phosphate fertilizer. Yam bean (Pachyrhizus erosus) inoculated with rhizobia (strains NFB 747 and NFB 748) or not inoculated was the test crop. Biofertilizers were produced in field furrows by mixing phosphate rock (PR) and sulphur inoculated with Acidithiobacillus (S+Ac) in different rates (50, 100, 150 and 200 g S kg(-1) PR), with 60 days of incubation. Treatments were carried out with PR; biofertilizers B(50), B(100), B(150), B(200); triple super phosphate (TSP); B(200) without Acidithiobacillus and a control treatment without P application (P(0)). TSP and biofertilizers plus S inoculated with Acidithiobacillus increased plant growth. Soil acidity and available P increased when biofertilizers B(150) and B(200) were applied. We conclude that biofertilizers may be used as P source; however, long term use will reduce soil pH and potentially reduce crop growth.

  9. Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite: Technical progress report, April 15--August 15, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Pesic, B.; Oliver, D.J.

    1989-01-01

    The results presented in the second trimester report (January 15--April 15, 1989) revealed very important phenomena occurring on pyrite surface during fermentation of Thiobacillus ferrooxidans. The events happening on the pyrite surface were evaluated by cyclic voltametry. It was found that the pyrite surface does not change its properties during fermentation until the second day of fermentation. This was concluded by the identical cyclic voltamograms obtained at the beginning of fermentation and after one day of fermentation, which were drastically different from the cyclic voltamograms after two days of fermentation. To verify the reproducibility of results and the importance of the second day of fermentation about five more sets of cyclic voltamograms as a function of fermentation time were produced. This resulted in about 500 experiments and 2 months of continuous experimentation. Also, some errors found in the previous reports were corrected in this report. Each time, it was found that the most drastic pyrite surface property changes happened after two days of fermentation. Thus, the major focus of the future research will be to elucidate the importance of the second day of fermentation and the subsequent phenomena. 16 figs.

  10. Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Bobadilla Fazzini, Roberto A; Cortés, Maria Paz; Padilla, Leandro; Maturana, Daniel; Budinich, Marko; Maass, Alejandro; Parada, Pilar

    2013-08-01

    The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications. Copyright © 2013 Wiley Periodicals, Inc.

  11. Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

    2016-11-01

    The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Bioleaching of ultramafic tailings by acidithiobacillus spp. for CO2 sequestration.

    Science.gov (United States)

    Power, Ian M; Dipple, Gregory M; Southam, Gordon

    2010-01-01

    Bioleaching experiments using various acid-generating substances, i.e., metal sulfides and elemental sulfur, were conducted to demonstrate the accelerated dissolution of chrysotile tailings collected from an asbestos mine near Clinton Creek, Yukon, Canada. Columns, possessing an acid-generating substance colonized with Acidithiobacillus sp., produced leachates with magnesium concentrations that were an order of magnitude greater than mine site waters or control column leachates. In addition, chrysotile tailings were efficient at neutralizing acidity, which resulted in the immobilization of metals (Fe, Cu, Zn) associated with the metal sulfide mine tailings that were used to generate acid. This suggests that tailings from acid mine drainage environments may be utilized to enhance chrysotile dissolution without polluting "downstream" ecosystems. These results demonstrate that the addition of an acid-generating substance in conjunction with a microbial catalyst can significantly enhance the release of magnesium ions, which are then available for the precipitation of carbonate minerals. This process, as part of a carbon dioxide sequestration program, has implications for reducing net greenhouse gas emissions in the mining industry.

  13. Occurrence and fluctuations of Acidithiobacillus ssp. in uranium mine effluents, Caldas, MG

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Michelle Burato de; Roque, Claudio Vitor; Gomes, Heliana de Azevedo [Brazilian Nuclear Energy Commission (CNEN-MG), Pocos de Caldas, MG (Brazil)]. E-mail: michelle_borato@hotmail.com; cvroque@cnen.gov.br; hgomes@cnen.gov.br

    2007-07-01

    Sulphide ores that are present in mining areas can cause serious environmental problems because of the action of chemolithotrophic bacteria of the Acidithiobacillus genera, mainly A. ferroxidans and A. thiooxidans. These microorganisms are capable of oxidizing sulphide minerals, elemental sulphur and ferrous ion, possibly mobilizing radionuclides such as uranium into the environment. In this context, the present study was undertaken in order to determine the occurrence and fluctuations of populations of A. ferroxidans and A. thiooxidans in effluents from an uranium mine, part of the Ore Treatment Unit (UTM) in Caldas, MG - Brazil, analyzing samples from 9 sampling points (CM, BS, D3, 25, 27, 32, 41, 75, and 76). The results showed that the population of A. thiooxidans occurs more often (44.4%) than the population of A. ferroxidans (31.5%). In the sample points within the UTM-environment interface, points 25 and 76 were considered the most susceptible to acid mine drainage and activity of bacteria involved in metal bioleaching. The seasonal behavior of some of the variables observed at points CM, D3, and BS, when evaluated simultaneously, such as high Eh values, low pH values, the detection of greater percentages of incidence and higher counts of A. ferroxidans and A. thiooxidans, showed that these points are the main locations for the occurrence of acid mine drainage and bacterial bioleaching in the UTM and should be considered as critical points for a possible decommissioning action. (author)

  14. Genome Sequence of the Acidophilic Ferrous Iron-Oxidizing Isolate Acidithrix ferrooxidans Strain Py-F3, the Proposed Type Strain of the Novel Actinobacterial Genus Acidithrix.

    Science.gov (United States)

    Eisen, Sebastian; Poehlein, Anja; Johnson, D Barrie; Daniel, Rolf; Schlömann, Michael; Mühling, Martin

    2015-04-30

    Extremely acidophilic iron-oxidizing Gram-positive bacteria comprise species within the phyla Firmicutes and Actinobacteria. Here, we report the 4.02-Mb draft genome of Acidithrix ferrooxidans Py-F3, which was isolated from a stream draining an abandoned copper mine and proposed as the type species of a new genus of Actinobacteria. Copyright © 2015 Eisen et al.

  15. Development of an automated water toxicity biosensor using Thiobacillus ferrooxidans for monitoring cyanides in natural water for a water filtering plant.

    Science.gov (United States)

    Okochi, Mina; Mima, Koji; Miyata, Maki; Shinozaki, Youhei; Haraguchi, Satoshi; Fujisawa, Minoru; Kaneko, Masao; Masukata, Tadashi; Matsunaga, Tadashi

    2004-09-30

    An on-line biosensor consisting of immobilized Thiobacillus ferrooxidans and an oxygen electrode was developed for automated monitoring of acute toxicity in water samples. T. ferrooxidans is an obligatory acidophilic, autotrophic bacterium and derives its energy by the oxidation of ferrous ion, elemental sulfur, and reduced sulfur compounds including metal sulfides. The assay is based on the monitoring of a current increase by addition of toxicoids, which is caused by the inhibition of bacterial respiration and decrease in oxygen consumption. Optimum cell number on the membrane was 5.0 x 10(8) cells. The steady-state current was obtained when concentration of FeSO4 was above 3.6 mM at pH 3. The sensor response of T. ferrooxidans immobilized membrane for 5.0 microM KCN was within an error of 10% for 30 membranes. A linear relationship was obtained at KCN concentration in the range of 0.5-3.0 microM in a flow-type monitoring system. Minimum detectable concentrations of KCN, Na2S, and NaN3 were 0.5, 1.2, and 0.07 microM, respectively. The monitoring system contained two biosensors and these sensors were cleaned with sulfuric acid (pH 1.5) twice a day. This treatment could remove fouling on microbial immobilized membrane by natural water and ferrous precipitation in the flow cell. This flow-type monitoring sensor was operated continuously for 5 months. Also, T. ferrooxidans immobilized membrane can be stored for one month at 4 degrees C when preserved with wet absorbent cotton under argon gas. Copyright 2004 Wiley Periodicals, Inc.

  16. Charge and softness of the outer part of the cell wall of Thiobacillus ferrooxidans in the low ionic strength medium

    Directory of Open Access Journals (Sweden)

    Škvarla Jiří

    2002-03-01

    Full Text Available The surface charge and surface potential are parameters influencing the microbial adhesion phenomenon through the electrostatic interaction between bacteria and substrates. The Smoluchowski equation, originally developed for estimating the above parameters from the experimentally accessible electrophoretic mobility of rigid colloid particles, is however inapplicable to the elastic bacterial cells. The problem is that the outer cell wall of bacteria is a layer with a complex polyelectrolyte structure. In this article, the OhshimaLs model of the gsofth particle is applied to describe the surface electrostatics of Thiobacillus ferrooxidans cells by measuring their electrophoretic mobility in distilled water as a function of a (low ionic strength and pH. In this model, the rigid core is considered to be covered with a charged ion-penetrable layer of polyelectrolytes. Two model parameters have been determined by the curve fitting at pH from 3.2 to 5.8, namely the number density of the dissociated groups N and the softness parameter 1/ƒÉ of the polyelectrolyte layer of the bacterium. A disagreement of the best fit parameters (evaluated by the correlation coefficient with the analogous parameters determined for other colloids (including bacterial cells in aqueous solutions of a high ionic strength is discussed.

  17. Microbial community succession mechanism coupling with adaptive evolution of adsorption performance in chalcopyrite bioleaching.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    The community succession mechanism of Acidithiobacillus sp. coupling with adaptive evolution of adsorption performance were systematically investigated. Specifically, the μmax of attached and free cells was increased and peak time was moved ahead, indicating both cell growth of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was promoted. In the mixed strains system, the domination courses of A. thiooxidans was dramatically shortened from 22th day to 15th day, although community structure finally approached to the normal system. Compared to A. ferrooxidans, more positive effects of adaptive evolution on cell growth of A. thiooxidans were shown in either single or mixed strains system. Moreover, higher concentrations of sulfate and ferric ions indicated that both sulfur and iron metabolism was enhanced, especially of A. thiooxidans. Consistently, copper ion production was improved from 65.5 to 88.5 mg/L. This new adaptive evolution and community succession mechanism may be useful for guiding similar bioleaching processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Comparative Genome Analysis Provides Insights into Both the Lifestyle of Acidithiobacillus ferrivorans Strain CF27 and the Chimeric Nature of the Iron-Oxidizing Acidithiobacilli Genomes.

    Science.gov (United States)

    Tran, Tam T T; Mangenot, Sophie; Magdelenat, Ghislaine; Payen, Emilie; Rouy, Zoé; Belahbib, Hassiba; Grail, Barry M; Johnson, D Barrie; Bonnefoy, Violaine; Talla, Emmanuel

    2017-01-01

    The iron-oxidizing species Acidithiobacillus ferrivorans is one of few acidophiles able to oxidize ferrous iron and reduced inorganic sulfur compounds at low temperatures (<10°C). To complete the genome of At. ferrivorans strain CF27, new sequences were generated, and an update assembly and functional annotation were undertaken, followed by a comparative analysis with other Acidithiobacillus species whose genomes are publically available. The At. ferrivorans CF27 genome comprises a 3,409,655 bp chromosome and a 46,453 bp plasmid. At. ferrivorans CF27 possesses genes allowing its adaptation to cold, metal(loid)-rich environments, as well as others that enable it to sense environmental changes, allowing At. ferrivorans CF27 to escape hostile conditions and to move toward favorable locations. Interestingly, the genome of At. ferrivorans CF27 exhibits a large number of genomic islands (mostly containing genes of unknown function), suggesting that a large number of genes has been acquired by horizontal gene transfer over time. Furthermore, several genes specific to At. ferrivorans CF27 have been identified that could be responsible for the phenotypic differences of this strain compared to other Acidithiobacillus species. Most genes located inside At. ferrivorans CF27-specific gene clusters which have been analyzed were expressed by both ferrous iron-grown and sulfur-attached cells, indicating that they are not pseudogenes and may play a role in both situations. Analysis of the taxonomic composition of genomes of the Acidithiobacillia infers that they are chimeric in nature, supporting the premise that they belong to a particular taxonomic class, distinct to other proteobacterial subgroups.

  19. Comparative Genome Analysis Provides Insights into Both the Lifestyle of Acidithiobacillus ferrivorans Strain CF27 and the Chimeric Nature of the Iron-Oxidizing Acidithiobacilli Genomes

    Directory of Open Access Journals (Sweden)

    Tam T. T. Tran

    2017-06-01

    Full Text Available The iron-oxidizing species Acidithiobacillus ferrivorans is one of few acidophiles able to oxidize ferrous iron and reduced inorganic sulfur compounds at low temperatures (<10°C. To complete the genome of At. ferrivorans strain CF27, new sequences were generated, and an update assembly and functional annotation were undertaken, followed by a comparative analysis with other Acidithiobacillus species whose genomes are publically available. The At. ferrivorans CF27 genome comprises a 3,409,655 bp chromosome and a 46,453 bp plasmid. At. ferrivorans CF27 possesses genes allowing its adaptation to cold, metal(loid-rich environments, as well as others that enable it to sense environmental changes, allowing At. ferrivorans CF27 to escape hostile conditions and to move toward favorable locations. Interestingly, the genome of At. ferrivorans CF27 exhibits a large number of genomic islands (mostly containing genes of unknown function, suggesting that a large number of genes has been acquired by horizontal gene transfer over time. Furthermore, several genes specific to At. ferrivorans CF27 have been identified that could be responsible for the phenotypic differences of this strain compared to other Acidithiobacillus species. Most genes located inside At. ferrivorans CF27-specific gene clusters which have been analyzed were expressed by both ferrous iron-grown and sulfur-attached cells, indicating that they are not pseudogenes and may play a role in both situations. Analysis of the taxonomic composition of genomes of the Acidithiobacillia infers that they are chimeric in nature, supporting the premise that they belong to a particular taxonomic class, distinct to other proteobacterial subgroups.

  20. The Effect of Oxygen Supply on the Dual Growth Kinetics of Acidithiobacillus thiooxidans under Acidic Conditions for Biogas Desulfurization

    Science.gov (United States)

    Namgung, Hyeong-Kyu; Song, JiHyeon

    2015-01-01

    In this study, to simulate a biogas desulfurization process, a modified Monod-Gompertz kinetic model incorporating a dissolved oxygen (DO) effect was proposed for a sulfur-oxidizing bacterial (SOB) strain, Acidithiobacillus thiooxidans, under extremely acidic conditions of pH 2. The kinetic model was calibrated and validated using experimental data obtained from a bubble-column bioreactor. The SOB strain was effective for H2S degradation, but the H2S removal efficiency dropped rapidly at DO concentrations less than 2.0 mg/L. A low H2S loading was effectively treated with oxygen supplied in a range of 2%–6%, but a H2S guideline of 10 ppm could not be met, even with an oxygen supply greater than 6%, when the H2S loading was high at a short gas retention time of 1 min and a H2S inlet concentration of 5000 ppm. The oxygen supply should be increased in the aerobic desulfurization to meet the H2S guideline; however, the excess oxygen above the optimum was not effective because of the decline in oxygen efficiency. The model estimation indicated that the maximum H2S removal rate was approximately 400 ppm/%-O2 at the influent oxygen concentration of 4.9% under the given condition. The kinetic model with a low DO threshold for the interacting substrates was a useful tool to simulate the effect of the oxygen supply on the H2S removal and to determine the optimal oxygen concentration. PMID:25633028

  1. The σ54-dependent two-component system regulating sulfur oxidization (Sox) system in Acidithiobacillus caldus and some chemolithotrophic bacteria.

    Science.gov (United States)

    Li, Li-Feng; Fu, Luo-Jie; Lin, Jian-Qun; Pang, Xin; Liu, Xiang-Mei; Wang, Rui; Wang, Zhao-Bao; Lin, Jian-Qiang; Chen, Lin-Xu

    2017-03-01

    The sulfur oxidization (Sox) system is the central sulfur oxidization pathway of phototrophic and chemotrophic sulfur-oxidizing bacteria. Regulation and function of the Sox system in the chemotrophic Paracoccus pantotrophus has been elucidated; however, to date, no information is available on the regulation of this system in the chemolithotrophic Acidithiobacillus caldus, which is widely utilized in bioleaching. We described the novel tspSR-sox-like clusters in A. caldus and other chemolithotrophic sulfur-oxidizing bacteria containing Sox systems. The highly homologous σ54-dependent two-component signaling system (TspS/R), upstream of the sox operons in these novel clusters, was identified by phylogenetic analyses. A typical σ54-dependent promoter, P1, was identified upstream of soxX-I in the sox-I cluster of A. caldus MTH-04. The transcriptional start site (G) and the -12/-24 regions (GC/GG) of P1 were determined by rapid amplification of cDNA ends (5'RACE), and the upstream activator sequences (UASs; TGTCCCAAATGGGACA) were confirmed by electrophoretic mobility shift assays (EMSAs) in vitro and by UAS-probe-plasmids assays in vivo. Sequence analysis of promoter regions in tspSR-sox-like clusters revealed that there were similar σ54-dependent promoters upstream of the soxX genes. Based on our results, we proposed a TspSR-mediated signal transduction and transcriptional regulation pathway for the Sox system in A. caldus. The regulation of σ54-dependent two-component systems (TCSs) for Sox pathways were explained for the first time in A. caldus, A. thiooxidans, T. tepidarius, and T. denitrificans, indicating the significance of modulating the sulfur oxidization in these chemolithotrophic sulfur oxidizers.

  2. Phosphate Favors the Biosynthesis of CdS Quantum Dots in Acidithiobacillus thiooxidans ATCC 19703 by Improving Metal Uptake and Tolerance

    Directory of Open Access Journals (Sweden)

    Giovanni Ulloa

    2018-02-01

    Full Text Available Recently, we reported the production of Cadmium sulfide (CdS fluorescent semiconductor nanoparticles (quantum dots, QDs by acidophilic bacteria of the Acidithiobacillus genus. Here, we report that the addition of inorganic phosphate to Acidithiobacillus thiooxidans ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5. The effect of pH, phosphate and cadmium concentrations on QDs biosynthesis was studied by using Response Surface Methodology (RSM, a multivariate technique for analytical optimization scarcely used in microbiological studies to date. To address how phosphate affects intracellular biosynthesis of CdS QDs, the effect of inorganic phosphate on bacterial cadmium-uptake was evaluated. By measuring intracellular levels of cadmium we determined that phosphate influences the capacity of cells to incorporate this metal. A relation between cadmium tolerance and phosphate concentrations was also determined, suggesting that phosphate participates in the adaptation of bacteria to toxic levels of this metal. In addition, QDs-biosynthesis was also favored by the degradation of intracellular polyphosphates. Altogether, our results indicate that phosphate contributes to A. thiooxidans CdS QDs biosynthesis by influencing cadmium uptake and cadmium tolerance. These QDs may also be acting as a nucleation point for QDs formation at acidic pH. This is the first study reporting the effect of phosphates on QDs biosynthesis and describes a new cadmium-response pathway present in A. thiooxidans and most probably in other bacterial species.

  3. Chemical and surface analysis during evolution of arsenopyrite oxidation by Acidithiobacillus thiooxidans in the presence and absence of supplementary arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Aldaba, Hugo [Facultad de Ciencias Químicas, Departamento de Ciencia de Materiales, Universidad Juárez del Estado de Durango (UJED), Av. Veterinaria S/N, Circuito Universitario, Col. Valle del Sur, 34120 Durango, Dgo (Mexico); Valles, O. Paola [Facultad de Ciencias Químicas, Departamento de Ciencia de Materiales, Universidad Juárez del Estado de Durango (UJED), Av. Veterinaria S/N, Circuito Universitario, Col. Valle del Sur, 34120 Durango, Dgo (Mexico); Instituto Tecnológico de Durando, UPIDET, Av. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080 Durango, Dgo (Mexico); Vazquez-Arenas, Jorge [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Iztapalapa, México DF 09340 (Mexico); Rojas-Contreras, J. Antonio [Instituto Tecnológico de Durando, UPIDET, Av. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080 Durango, Dgo (Mexico); Valdez-Pérez, Donato [Instituto Politécnico Nacional, UPALM, Edif. Z-4 3er Piso, CP 07738 México D.F (Mexico); Ruiz-Baca, Estela [Facultad de Ciencias Químicas, Departamento de Ciencia de Materiales, Universidad Juárez del Estado de Durango (UJED), Av. Veterinaria S/N, Circuito Universitario, Col. Valle del Sur, 34120 Durango, Dgo (Mexico); and others

    2016-10-01

    Bioleaching of arsenopyrite presents a great interest due to recovery of valuable metals and environmental issues. The current study aims to evaluate the arsenopyrite oxidation by Acidithiobacillus thiooxidans during 240 h at different time intervals, in the presence and absence of supplementary arsenic. Chemical and electrochemical characterizations are carried out using Raman, AFM, SEM-EDS, Cyclic Voltammetry, EIS, electrophoretic and adhesion forces to comprehensively assess the surface behavior and biooxidation mechanism of this mineral. These analyses evidence the formation of pyrite-like secondary phase on abiotic control surfaces, which contrast with the formation of pyrite (FeS{sub 2})-like, orpiment (As{sub 2}S{sub 3})-like and elementary sulfur and polysulfide (S{sub n}{sup 2−}/S{sup 0}) phases found on biooxidized surfaces. Voltammetric results indicate a significant alteration of arsenopyrite due to (bio)oxidation. Resistive processes determined with EIS are associated with chemical and electrochemical reactions mediated by (bio)oxidation, resulting in the transformation of arsenopyrite surface and biofilm direct attachment. Charge transfer resistance is increased when (bio)oxidation is performed in the presence of supplementary arsenic, in comparison with lowered abiotic control resistances obtained in its absence; reinforcing the idea that more stable surface products are generated when As(V) is in the system. Biofilm structure is mainly comprised of micro-colonies, progressively enclosed in secondary compounds. A more compact biofilm structure with enhanced formation of secondary compounds is identified in the presence of supplementary arsenic, whereby variable arsenopyrite reactivity is linked and attributed to these secondary compounds, including S{sub n}{sup 2−}/S{sup 0}, pyrite-like and orpiment-like phases. - Highlights: • Biofilm structures occur as compact micro-colonies. • Surface transformation reactions control arsenopyrite and cell

  4. Isolation of Thiobacillus spp . and its application in the removal of ...

    African Journals Online (AJOL)

    In addition, we demonstrate for the first time that bioleaching can reduce the pathogenicity of sludge by detecting fecal coliforms before and after bioleaching in order to ensure that the sludge was suitable for agricultural land application. Key words: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, excess ...

  5. Isolation of Thiobacillus spp. and its application in the removal of ...

    African Journals Online (AJOL)

    uwerhiavwe

    Two strains of Thiobacillus isolated from native excess activated sludge were identified as. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans by 16S rRNA gene sequencing and physiological-biochemical characteristics. Single and mixed cultures of the strains were used to carry out bioleaching for 9 days in ...

  6. Author Details - African Journals Online

    African Journals Online (AJOL)

    Jing, Yanjun. Vol 15, No 5 (2016) - Articles Arsenic bioleaching in medical realgar ore and arsenicbearing refractory gold ore by combination of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. Abstract PDF. ISSN: 1596-9827. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

  7. Browse Title Index - African Journals Online

    African Journals Online (AJOL)

    Items 351 - 400 of 1932 ... Vol 15, No 5 (2016), Arsenic bioleaching in medical realgar ore and arsenicbearing refractory gold ore by combination of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, Abstract PDF. Feifan Leng, Shangchen Sun, Yonggang Wang, Yanjun Jing, Qingwei Wei, Hongyu Li. Vol 14, No ...

  8. Cowpea nodulation, biomass yield and nutrient uptake, as affected by biofertilizers and rhizobia, in a sodic soil amended with Acidithiobacillus - doi: 10.4025/actasciagron.v35i4.16994

    Directory of Open Access Journals (Sweden)

    Newton Pereira Stamford

    2013-05-01

    Full Text Available Sodic soils require application of amendments as gypsum and organic matter. Many types of compost have been tested in sodic soils reclamation; however, these materials often do not provide satisfactory pH reduction. A recent study reported effective effects applying mixture of gypsum and sulfur inoculated with Acidithiobacillus in sodic soils with high pH and exchangeable sodium, though the effects on plant parameters were not evaluated. The present study was conducted to verify the effects of BPK rock biofertilizers on nodulation, biomass yield and nutrient uptake in cowpea compared with mineral fertilizer after sodic soil amendment. The BPK biofertilizers and PK mineral fertilizer were applied at different rates, and plants were inoculated with effective rhizobia strains. A control that did not receive PK fertilization was included. The results indicated that gypsum and sulfur with Acidithiobacillus reduced the soil’s pH and the amount of soil exchangeable sodium. BPK rock biofertilizer increased cowpea nodulation, biomass yield and nutrient uptake. The native rhizobia in the soil exhibited effectiveness in cowpea growth; displaying similar results compared with the rhizobia inoculated plants. BPK biofertilizers may be used as alternative to mineral PK fertilizers in sodic soils after the application of gypsum and sulfur inoculated with Acidithiobacillus.

  9. Construction of novel pJRD215-derived plasmids using chloramphenicol acetyltransferase (cat gene as a selection marker for Acidithiobacillus caldus.

    Directory of Open Access Journals (Sweden)

    Rui Wang

    Full Text Available Acidithiobacillus caldus, a Gram-negative, chemolithotrophic sulfur-oxidizing bacterium, is widely applied in bioleaching. The absence of an ideal selection marker has become a major obstacle to achieve high efficiency of the gene transfer system for A. caldus. Plasmid pJRD215, widely used in Acidithiobacillus spp., has severe drawbacks in molecular manipulations and potential biosafety issues due to its mobility. Therefore, finding a new selection marker and constructing new plasmids have become an urgent and fundamental work for A. caldus.Effective inhibitory effect of chloramphenicol on the growth of A. caldus was elucidated for the first time. The P2-cat gene cassette, including a chloramphenicol acetyltransferase gene (cat from plasmid pACBSR and a promoter (P2 upstream of the tetracycline resistance gene on pBR322, was designed, chloramphenicol acetyltransferase was expressed in A. caldus, and the enzyme activity was assessed. A new vector pSDU1 carrying the replication and mobilization regions derived from pJRD215, the P2-cat gene cassette and a multiple cloning site from pUC19 was successfully constructed. Compared with pJRD215, pSDU1 had a 27-fold increase in electrotransformation efficiency (30.43±0.88×104 CFU/μg DNA for pSDU1 and 1.09±0.11×104 CFU/μg DNA for pJRD215, better carrying capacity and could offer more convenience for the restriction enzyme digestion. In addition, the generated plasmid pSDU1Δmob, a novel non-mobilizable derivative of pSDU1 lacking some DNA sequences involved in the mobilization process, had increased copy number in A. caldus and lost its mobility for biosafety considerations. Both pSDU1 and pSDU1Δmob exhibited stable maintenance in A. caldus within 50 passages. However, further deletion of orfEF region involved in regulating repAC operon resulted in a negative effect on transformation efficiency, copy number and stability of plasmid pSDU1ΔmobΔorfEF in A. caldus.Chloramphenicol was proved to be an

  10. Metabolic Myopathies

    Science.gov (United States)

    ... Am A Patient / Caregiver Diseases & Conditions Metabolic Myopathies Metabolic Myopathies Fast Facts Metabolic myopathies are rare genetic ... no family history of the condition. What are metabolic myopathies? Metabolic myopathies are genetic defects that interfere ...

  11. Properties of realgar bioleaching using an extremely acidophilic bacterium and its antitumor mechanism as an anticancer agent

    OpenAIRE

    Chen, Peng; Xu, Ruixiang; Yan, Lei; Wu, Zhengrong; Wei, Yan; Zhao, Wenbin; Wang, Xin; Xie, Qinjian; Li, Hongyu

    2017-01-01

    Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese). It contains over 90% tetra-arsenic tetra-sulfide (As4S4). Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans). Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for...

  12. Metabolic Panel

    Science.gov (United States)

    A metabolic panel is a group of tests that measures different chemicals in the blood. These tests are usually ... kidneys and liver. There are two types: basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). The ...

  13. Metabolic acidosis

    Science.gov (United States)

    Acidosis - metabolic ... Metabolic acidosis occurs when the body produces too much acid. It can also occur when the kidneys ... from the body. There are several types of metabolic acidosis. Diabetic acidosis develops when acidic substances, known ...

  14. Metabolic neuropathies

    Science.gov (United States)

    Neuropathy - metabolic ... damage can be caused by many different things. Metabolic neuropathy may be caused by: A problem with ... is one of the most common causes of metabolic neuropathies. People who are at the highest risk ...

  15. Metabolic flexibility

    National Research Council Canada - National Science Library

    Storlien, Len; Oakes, Nick D; Kelley, David E

    2004-01-01

    ...). Such capacities characterize the healthy state and can be termed 'metabolic flexibility'. However, increasing evidence points to metabolic inflexibility as a key dysfunction of the cluster of disease states encompassed by the term 'metabolic syndrome...

  16. Modeling effluent heavy metal concentrations in a bioleaching ...

    African Journals Online (AJOL)

    SONY

    Artifical neural networks practices were used to predict the recovery of heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) from dewatered metal plating sludge (with no sulfide or sulfate compounds) using bioleaching process involving Acidithiobacillus ferrooxidans. The bioleaching process was operated as a completely mixed batch ...

  17. Redox status affects the catalytic activity of glutamyl-tRNA synthetase

    DEFF Research Database (Denmark)

    Katz, Assaf; Banerjee, Rajat; de Armas, Merly

    2010-01-01

    in tetrapyrrole biosynthesis is not known. Previous studies have shown that GluRS1, one of two GluRSs from the extremophile Acidithiobacillus ferrooxidans, is inactivated when intracellular heme is elevated suggesting a specific role for GluRS1 in the regulation of tetrapyrrole biosynthesis. We now show that...

  18. Structure/function relationship of the rusticyanin among thiobacillus ferroxidans: from the fermenter to the crystal; Relations structure/fonction de la rusticyanine chez thiobacillus ferrooxidans: du fermenteur au cristal

    Energy Technology Data Exchange (ETDEWEB)

    Nunzi, F.

    1996-09-23

    The commercial extraction of copper and uranium from ores by microbial leaching turns to account the iron oxidation capacity of Thiobacillus ferroxidans. The iron oxidation involves an electron transport chain localized in the peri-plasmic space of the cell. The aim of our work is to study the structure-function relationships of rusticyanin, the most important component of this respiratory chain. Rusticyanin is a blue copper protein and has been characterized from a new strain of Thilbacillus ferrooxidans. A preliminary electrochemical study has been made with a new modified-gold electrode and we have examined, in particular, the pH dependence of the high redox potential of rusticyanin. Its amino acid sequence has been determined and a comparison with two other rusticyanin sequences, isolated from different strains, shows a high degree of homology. A structural alignment with six other blue copper proteins allows to propose four residues as copper ligands, His 84, Cys 138, His 143 and Met 148. The supposed factors responsible for the high redox potential of rusticyanin are discussed. (author)

  19. Metabolic Disorders

    Science.gov (United States)

    ... as your liver, muscles, and body fat. A metabolic disorder occurs when abnormal chemical reactions in your ... that produce the energy. You can develop a metabolic disorder when some organs, such as your liver ...

  20. Metabolic Syndrome

    Science.gov (United States)

    Metabolic syndrome is a group of conditions that put you at risk for heart disease and diabetes. These ... doctors agree on the definition or cause of metabolic syndrome. The cause might be insulin resistance. Insulin is ...

  1. Bacterial consortium for copper extraction from sulphide ore consisting mainly of chalcopyrite

    Directory of Open Access Journals (Sweden)

    E. Romo

    2013-01-01

    Full Text Available The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control.

  2. Microbes: uranium miners, money makers, problem solvers

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, A.L., E-mail: awilliamson@mirarco.org [MIRARCO, Sudbury, ON (Canada); Laurentian Univ., Sudbury, ON (Canada); Payne, R.; Kerr, F. [Pele Mountain Resources Inc., Toronto, ON (Canada); Hall, S. [Laurentian Univ., Sudbury, ON (Canada); Spiers, G.A. [MIRARCO, Sudbury, ON (Canada); Laurentian Univ., Sudbury, ON (Canada)

    2010-07-01

    Bioleaching, the microbial dissolution of minerals, is potentially useful in exploiting a variety of ore deposits, including the lower-grade uraniferous quartz-pebble conglomerate beds of the Quirke Syncline, Elliot Lake, Ontario. The metabolism of chemolithotropic bacterium Acidithiobacillus ferrooxidans is dependent on its ability to derive energy and reducing power from the oxidation of ferrous iron. The characteristics of this bacterium, in particular the ability to oxidize both iron and sulphur with an associated high tolerance of low acidity, allow the organism to contribute significantly to bioleaching processes. Under ideal conditions, A. ferrooxidans promotes the oxidation of iron-containing sulphide ore materials, breaking their crystal structure and promoting the dissolution of iron, base metals, as well as uranium, rare earth elements and associated elements of toxicological interest such as arsenic and selenium. The current study documents an overview of the recovery of uranium and rare earth elements to solution, plus investigates the acid generating potential of the solid residues from a series of environmentally controlled, biologically-mediated uranium ore extraction experiments. The findings will be used in the design of larger scale bioleaching experiments to further assess the potential for success of bioleaching as a metallurgical extraction technique potentially leading to minimum maintenance decommissioning strategies for the ore deposits of the Quirke Syncline. (author)

  3. Nucleotide Metabolism

    DEFF Research Database (Denmark)

    Martinussen, Jan; Willemoës, M.; Kilstrup, Mogens

    2011-01-01

    Metabolic pathways are connected through their utilization of nucleotides as supplier of energy, allosteric effectors, and their role in activation of intermediates. Therefore, any attempt to exploit a given living organism in a biotechnological process will have an impact on nucleotide metabolism....... The aim of this article is to provide knowledge of nucleotide metabolism and its regulation to facilitate interpretation of data arising from genetics, proteomics, and transcriptomics in connection with biotechnological processes and beyond....

  4. Metabolic myopathies

    Science.gov (United States)

    Martin, A.; Haller, R. G.; Barohn, R.; Blomqvist, C. G. (Principal Investigator)

    1994-01-01

    Metabolic myopathies are disorders of muscle energy production that result in skeletal muscle dysfunction. Cardiac and systemic metabolic dysfunction may coexist. Symptoms are often intermittent and provoked by exercise or changes in supply of lipid and carbohydrate fuels. Specific disorders of lipid and carbohydrate metabolism in muscle are reviewed. Evaluation often requires provocative exercise testing. These tests may include ischemic forearm exercise, aerobic cycle exercise, and 31P magnetic resonance spectroscopy with exercise.

  5. Metabolic Syndrome

    Science.gov (United States)

    ... much saturated fat, and does not get enough physical activity may develop metabolic syndrome. Other causes include insulin resistance and a family ... you’re overweight. It also includes getting more physical activity and eating a ... syndrome treatment If you already have metabolic syndrome, making ...

  6. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

    functional groups on which different reactions take place in the body. We have covered the detoxification pathways of drug metabolism; however, we still have to understand the toxic effects of drug metabolism via bioactivation process. 3.3 Bioactivation Reactions:Chemistry of Reactive Metabolites and Adverse Drug Effects.

  7. Metabolism of

    African Journals Online (AJOL)

    In many temperate woody species, short days (SDs) induced growth cessation has been shown to be prevented by the application of gibberellins (GAs). Evidence has also been forwarded for the influence of photoperiod on the metabolism of applied GAs. Continuing with this line of research, we studied the metabolism of ...

  8. [Metabolic acidosis].

    Science.gov (United States)

    Regolisti, Giuseppe; Fani, Filippo; Antoniotti, Riccardo; Castellano, Giuseppe; Cremaschi, Elena; Greco, Paolo; Parenti, Elisabetta; Morabito, Santo; Sabatino, Alice; Fiaccadori, Enrico

    2016-01-01

    Metabolic acidosis is frequently observed in clinical practice, especially among critically ill patients and/or in the course of renal failure. Complex mechanisms are involved, in most cases identifiable by medical history, pathophysiology-based diagnostic reasoning and measure of some key acid-base parameters that are easily available or calculable. On this basis the bedside differential diagnosis of metabolic acidosis should be started from the identification of the two main subtypes of metabolic acidosis: the high anion gap metabolic acidosis and the normal anion gap (or hyperchloremic) metabolic acidosis. Metabolic acidosis, especially in its acute forms with elevated anion gap such as is the case of lactic acidosis, diabetic and acute intoxications, may significantly affect metabolic body homeostasis and patients hemodynamic status, setting the stage for true medical emergencies. The therapeutic approach should be first aimed at early correction of concurrent clinical problems (e.g. fluids and hemodynamic optimization in case of shock, mechanical ventilation in case of concomitant respiratory failure, hemodialysis for acute intoxications etc.), in parallel to the formulation of a diagnosis. In case of severe acidosis, the administration of alkalizing agents should be carefully evaluated, taking into account the risk of side effects, as well as the potential need of renal replacement therapy.

  9. Drug Metabolism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 3. Drug Metabolism: A Fascinating Link Between Chemistry and Biology. Nikhil Taxak Prasad V Bharatam. General Article Volume 19 Issue 3 March 2014 pp 259-282 ...

  10. METABOLIC SYNDROME

    OpenAIRE

    Dikanović, Marinko

    2015-01-01

    Metabolic syndrome is a cluster of disorders that include hyperlipidemia, inadequate insulin resistance, hypertension, and abdominal type obesity. Patients who suffer from this syndrome have an increased risk for heart disease and blood vessel disease, stroke and type II diabetes. The world's leading healthcare institutions also disagree on the exact definition of this organization poremećaja. NCEP (National Cholesterol Education Program) defines metabolic syndrome as a situation in which the...

  11. Metabolic Syndrome (For Parents)

    Science.gov (United States)

    ... Needs a Kidney Transplant Vision Facts and Myths Metabolic Syndrome KidsHealth > For Parents > Metabolic Syndrome Print A A ... this is a condition called metabolic syndrome . About Metabolic Syndrome Not to be confused with metabolic disease (which ...

  12. What is Metabolic Syndrome?

    Science.gov (United States)

    ... Research Home / Metabolic Syndrome Metabolic Syndrome What Is Metabolic syndrome is the name for a group of risk ... three metabolic risk factors to be diagnosed with metabolic syndrome. A large waistline. This also is called abdominal ...

  13. Metabolic Engineering

    Indian Academy of Sciences (India)

    IAS Admin

    processes such as generation of energy, production of fundamen- tal building blocks required for structural organization and syn- thesis of biomolecules having specialized functions. ... Symbiosis International. University, Pune. His research interests are in metabolic engineering of lactic acid bacteria for increasing their.

  14. Metabolic Analysis

    Science.gov (United States)

    Tolstikov, Vladimir V.

    Analysis of the metabolome with coverage of all of the possibly detectable components in the sample, rather than analysis of each individual metabolite at a given time, can be accomplished by metabolic analysis. Targeted and/or nontargeted approaches are applied as needed for particular experiments. Monitoring hundreds or more metabolites at a given time requires high-throughput and high-end techniques that enable screening for relative changes in, rather than absolute concentrations of, compounds within a wide dynamic range. Most of the analytical techniques useful for these purposes use GC or HPLC/UPLC separation modules coupled to a fast and accurate mass spectrometer. GC separations require chemical modification (derivatization) before analysis, and work efficiently for the small molecules. HPLC separations are better suited for the analysis of labile and nonvolatile polar and nonpolar compounds in their native form. Direct infusion and NMR-based techniques are mostly used for fingerprinting and snap phenotyping, where applicable. Discovery and validation of metabolic biomarkers are exciting and promising opportunities offered by metabolic analysis applied to biological and biomedical experiments. We have demonstrated that GC-TOF-MS, HPLC/UPLC-RP-MS and HILIC-LC-MS techniques used for metabolic analysis offer sufficient metabolome mapping providing researchers with confident data for subsequent multivariate analysis and data mining.

  15. Estudo da dissolução oxidativa microbiológica de uma complexa amostra mineral contendo pirita (FeS2, Pirrotita (Fe1-xS e Molibdenita (MoS2 Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS2, pyrrotite (Fe1-xS and molybdenite (MoS2

    Directory of Open Access Journals (Sweden)

    Wilmo E. Francisco Jr

    2007-10-01

    Full Text Available This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferrooxidans. This study was performed by respirometric essays and bioleaching in shake flasks. Respirometric essays yielded the kinetics of mineral oxidation. The findings showed that sulfide oxidation followed classical Michaelis-Menten kinetics. Bioleaching in shake flasks allowed evaluation of chemical and mineralogical changes resulting from sulfide oxidation. The results demonstrated that pyrrotite and pyrite were completely oxidized in A. ferrooxidans cultures whereas molybdenite was not consumed. These data indicated that molybdenite was the most recalcitrant sulfide in the sample.

  16. Evaluación y caracterización mineralógica del proceso de biooxidación en un reactor continuo de tanque agitado

    OpenAIRE

    DIANA ARROYAVE G.; MARCO MÁRQUEZ G.; DARIO GALLEGO S.; GAMALIEL PACHECO

    2011-01-01

    La biooxidación del mineral refractario de oro de la mina El Zancudo (Titiribí-Antioquia) se realizó en un reactor continuo de tanque agitado usando microorganismos nativos acidófilos compatibles con Acidithiobacillus ferrooxidans y Acidithiobacillus thiooxidans. El reactor se operó inicialmente en discontinuo para alcanzar la máxima concentración de hierro férrico en solución, antes de iniciar el proceso en continuo. La caracterización mineralógica se hizo a muestras recolectadas en disconti...

  17. Production of Glycolic Acid by Chemolithotrophic Iron- and Sulfur-Oxidizing Bacteria and Its Role in Delineating and Sustaining Acidophilic Sulfide Mineral-Oxidizing Consortia▿

    Science.gov (United States)

    Ñancucheo, Ivan; Johnson, D. Barrie

    2010-01-01

    Glycolic acid was detected as an exudate in actively growing cultures of three chemolithotrophic acidophiles that are important in biomining operations, Leptospirillum ferriphilum, Acidithiobacillus (At.) ferrooxidans, and At. caldus. Although similar concentrations of glycolic acid were found in all cases, the concentrations corresponded to ca. 24% of the total dissolved organic carbon (DOC) in cultures of L. ferriphilum but only ca. 5% of the total DOC in cultures of the two Acidithiobacillus spp. Rapid acidification (to pH 1.0) of the culture medium of At. caldus resulted in a large increase in the level of DOC, although the concentration of glycolic acid did not change in proportion. The archaeon Ferroplasma acidiphilum grew in the cell-free spent medium of At. caldus; glycolic acid was not metabolized, although other unidentified compounds in the DOC pool were metabolized. Glycolic acid exhibited levels of toxicity with 21 strains of acidophiles screened similar to those of acetic acid. The most sensitive species were chemolithotrophs (L. ferriphilum and At. ferrivorans), while the most tolerant species were chemoorganotrophs (Acidocella, Acidobacterium, and Ferroplasma species), and the ability to metabolize glycolic acid appeared to be restricted (among acidophiles) to Firmicutes (chiefly Sulfobacillus spp.). Results of this study help explain why Sulfobacillus spp. rather than other acidophiles are the main organic carbon-degrading bacteria in continuously fed stirred tanks used to bioprocess sulfide mineral concentrates and also why temporary cessation of pH control in these systems, resulting in rapid acidification, often results in a plume of the archaeon Ferroplasma. PMID:19933342

  18. Metabolic Surgery

    DEFF Research Database (Denmark)

    Pareek, Manan; Schauer, Philip R; Kaplan, Lee M

    2018-01-01

    The alarming rise in the worldwide prevalence of obesity is paralleled by an increasing burden of type 2 diabetes mellitus. Metabolic surgery is the most effective means of obtaining substantial and durable weight loss in individuals with obesity. Randomized trials have recently shown the superio......The alarming rise in the worldwide prevalence of obesity is paralleled by an increasing burden of type 2 diabetes mellitus. Metabolic surgery is the most effective means of obtaining substantial and durable weight loss in individuals with obesity. Randomized trials have recently shown...... the superiority of surgery over medical treatment alone in achieving improved glycemic control, as well as a reduction in cardiovascular risk factors. The mechanisms seem to extend beyond the magnitude of weight loss alone and include improvements in incretin profiles, insulin secretion, and insulin sensitivity...

  19. Cross-Comparison of Leaching Strains Isolated from Two Different Regions: Chambishi and Dexing Copper Mines

    Directory of Open Access Journals (Sweden)

    Baba Ngom

    2014-01-01

    Full Text Available A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa and Dexing copper mine (China, Asia, was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.

  20. Acidithiobacillus caldus, Leptospirillum spp., Ferroplasma spp. and ...

    African Journals Online (AJOL)

    human body functions, their ingestion in high quantities can result in severe health implications which in some ... on single species of heavy metal-ion uptake in solution by vari- ous micro-organisms is well reported, the .... Therefore, for the larger anhydrite ions, with the charge more dispersed, the water of hydration is held ...

  1. Dementia due to metabolic causes

    Science.gov (United States)

    Chronic brain - metabolic; Mild cognitive - metabolic; MCI - metabolic ... Possible metabolic causes of dementia include: Hormonal disorders, such as Addison disease , Cushing disease Heavy metal exposure, such as ...

  2. Comprehensive metabolic panel

    Science.gov (United States)

    Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20 ... Chernecky CC, Berger BJ. Comprehensive metabolic panel (CMP) - ... Diagnostic Procedures . 6th ed. St Louis, MO: Elsevier Saunders; ...

  3. Carbohydrate Metabolism Disorders

    Science.gov (United States)

    ... you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system (enzymes) ... metabolic disorder, something goes wrong with this process. Carbohydrate metabolism disorders are a group of metabolic disorders. ...

  4. Degradation of inhibitory substances in sludge by Galactomyces sp. Z3 and the role of its extracellular polymeric substances in improving bioleaching.

    Science.gov (United States)

    Zhou, Jun; Zheng, Guanyu; Wong, Jonathan W C; Zhou, Lixiang

    2013-03-01

    This study sought to elucidate the effect and mechanism of Galactomyces sp. Z3 in improving the bioleaching of heavy metals from sludge. Results showed that co-inoculation of Galactomyces sp. Z3 and two Acidithiobacillus strains (Acidithiobacillus ferrooxidans LX5 and Acidithiobacillus thiooxidans TS6) reduced the period required for sludge bioleaching by 4.5days compared to Acidithiobacillus alone. Further, removal efficiencies of Cu, Zn and oxidation rate of Fe(2+) and S(0) were higher in co-inoculation system than the Acidithiobacillus alone. Galactomyces sp. Z3 consumed the acetate, propionate, iso-butyrate, butyrate, and iso-valerate in sludge from the initial concentrations of 109.50, 28.80, 7.70, 34.30, and 18.40mg/L to 10.20, 0.61, 0.63, 19.40 and 1.30mg/L, respectively, after 12h in the co-inoculation system, significantly lower than the concentrations observed in the Acidithiobacillus alone. Meanwhile, the surfactant properties of the extracellular polymeric substances produced by the Galactomyces accelerated the rate of sulfur oxidization by A. thiooxidans. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Cancer stem cell metabolism

    National Research Council Canada - National Science Library

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    .... Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes...

  6. Profiling metabolic networks to study cancer metabolism.

    Science.gov (United States)

    Hiller, Karsten; Metallo, Christian M

    2013-02-01

    Cancer is a disease of unregulated cell growth and survival, and tumors reprogram biochemical pathways to aid these processes. New capabilities in the computational and bioanalytical characterization of metabolism have now emerged, facilitating the identification of unique metabolic dependencies that arise in specific cancers. By understanding the metabolic phenotype of cancers as a function of their oncogenic profiles, metabolic engineering may be applied to design synthetically lethal therapies for some tumors. This process begins with accurate measurement of metabolic fluxes. Here we review advanced methods of quantifying pathway activity and highlight specific examples where these approaches have uncovered potential opportunities for therapeutic intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. [Porphyrin metabolism in women with metabolic syndrome].

    Science.gov (United States)

    Krivosheev, A B; Kuimov, A D; Kondratova, M A; Tuguleva, T A

    2014-01-01

    A total of 47 women with metabolic syndrome (MS) were examined with the fractional determination of porphyrins in urine (uroporphyrin and coproporphyrin) and feces (coproporphyrin and protoporphyrin) as well as their precursors (5-aminolevulinic acid and porphobilinogen). Disorders of porphyrin metabolism were documented in 29 (61.7%) women All patients had elevated levels of porphyrin precursors. Five women exhibited qualitative changes in the form of abnormal ratios of different porphyrin fractions(coproporphyrin/uroporphyrin porphyrin metabolism in the form of manifold increase of porphyrin levels in urine and/or feces and formation of biochemical syndromes of secondary coproporphyrinuiria, symptomatic rise in porphyrin content in feces, and chronic latent hepatic porfiria. Disorders of porphyrin metabolism were associated with insulin resistance. Changes of porphyrin metabolism in MS extend the spectrum of concomitant disturbances and can be regarded as an additional criterion.

  8. Inborn errors of metabolism

    Science.gov (United States)

    ... metabolism. A few of them are: Fructose intolerance Galactosemia Maple sugar urine disease (MSUD) Phenylketonuria (PKU) Newborn ... disorder. Alternative Names Metabolism - inborn errors of Images Galactosemia Phenylketonuria test References Bodamer OA. Approach to inborn ...

  9. BMP (Basic Metabolic Panel)

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Basic Metabolic Panel (BMP) Send Us Your Feedback Choose ... Screen Chem 7 SMA 7 SMAC7 Formal Name Basic Metabolic Panel This article was last reviewed on ...

  10. Basic metabolic panel

    Science.gov (United States)

    ... Sequential multi-channel analysis with computer-7; SMA7; Metabolic panel 7; CHEM-7 ... Bope ET, Kellerman RD. Endocrine and metabolic disorders. In: Bope ET, ... PA: Elsevier; 2017:chap 5. Oh MS, Briefel G. Evaluation ...

  11. Metabolic networks of longevity

    NARCIS (Netherlands)

    Houtkooper, Riekelt H.; Williams, Robert W.; Auwerx, Johan

    2010-01-01

    Molecular and cellular networks implicated in aging depend on a multitude of proteins that collectively mount adaptive and contingent metabolic responses to environmental challenges. Here, we discuss the intimate links between metabolic regulation and longevity and outline new approaches for

  12. Cold-induced metabolism

    NARCIS (Netherlands)

    van Marken Lichtenbelt, W.D.; Daanen, A.M.

    2003-01-01

    Cold-induced metabolism. van Marken Lichtenbelt WD, Daanen HA. Department of Human Biology, Maastricht University, Maastricht, The Netherlands. PURPOSE OF REVIEW: Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering

  13. Cold-induced metabolism

    NARCIS (Netherlands)

    Van Marken Lichtenbelt, Wouter D.; Daanen, Hein A M

    Purpose of review: Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering thermogenesis by sympathetic, norepinephrine-induced mitochondrial heat production in brown adipose tissue is a well known component of this metabolic

  14. Cold-induced metabolism

    NARCIS (Netherlands)

    Lichtenbelt, W. van Marken; Daanen, H.A.M.

    2003-01-01

    Purpose of review Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering thermogenesis by sympathetic, norepinephrine-induced mitochondrial heat production in brown adipose tissue is a well known component of this metabolic

  15. Metabolism and disease

    National Research Council Canada - National Science Library

    Grodzicker, Terri; Stewart, David J; Stillman, Bruce

    2011-01-01

    ...), cellular, organ system (cardiovascular, bone), and organismal (timing and life span) scales. Diseases impacted by metabolic imbalance or dysregulation that were covered in detail included diabetes, obesity, metabolic syndrome, and cancer...

  16. Lipid Metabolism Disorders

    Science.gov (United States)

    ... metabolic disorder, something goes wrong with this process. Lipid metabolism disorders, such as Gaucher disease and Tay-Sachs disease, involve lipids. Lipids are fats or fat-like substances. They ...

  17. Genomic insights into microbial iron oxidation and iron uptake strategies in extremely acidic environments.

    Science.gov (United States)

    Bonnefoy, Violaine; Holmes, David S

    2012-07-01

    This minireview presents recent advances in our understanding of iron oxidation and homeostasis in acidophilic Bacteria and Archaea. These processes influence the flux of metals and nutrients in pristine and man-made acidic environments such as acid mine drainage and industrial bioleaching operations. Acidophiles are also being studied to understand life in extreme conditions and their role in the generation of biomarkers used in the search for evidence of existing or past extra-terrestrial life. Iron oxidation in acidophiles is best understood in the model organism Acidithiobacillus ferrooxidans. However, recent functional genomic analysis of acidophiles is leading to a deeper appreciation of the diversity of acidophilic iron-oxidizing pathways. Although it is too early to paint a detailed picture of the role played by lateral gene transfer in the evolution of iron oxidation, emerging evidence tends to support the view that iron oxidation arose independently more than once in evolution. Acidic environments are generally rich in soluble iron and extreme acidophiles (e.g. the Leptospirillum genus) have considerably fewer iron uptake systems compared with neutrophiles. However, some acidophiles have been shown to grow as high as pH 6 and, in the case of the Acidithiobacillus genus, to have multiple iron uptake systems. This could be an adaption allowing them to respond to different iron concentrations via the use of a multiplicity of different siderophores. Both Leptospirillum spp. and Acidithiobacillus spp. are predicted to synthesize the acid stable citrate siderophore for Fe(III) uptake. In addition, both groups have predicted receptors for siderophores produced by other microorganisms, suggesting that competition for iron occurs influencing the ecophysiology of acidic environments. Little is known about the genetic regulation of iron oxidation and iron uptake in acidophiles, especially how the use of iron as an energy source is balanced with its need to take up

  18. Integrative metabolic engineering

    OpenAIRE

    George H McArthur IV; Pooja P Nanjannavar; Emily H Miller; Stephen S. Fong

    2015-01-01

    Recent advances in experimental and computational synthetic biology are extremely useful for achieving metabolic engineering objectives. The integration of synthetic biology and metabolic engineering within an iterative design-build-test framework will improve the practice of metabolic engineering by relying more on efficient design strategies. Computational tools that aid in the design and in silico simulation of metabolic pathways are especially useful. However, software helpful for constru...

  19. Metabolic Syndrome and Migraine

    OpenAIRE

    Amit eSachdev; Michael eMarmura

    2012-01-01

    Migraine and metabolic syndrome are highly prevalent and costly conditions. The two conditions coexist, but it is unclear what relationship may exist between the two processes. Metabolic syndrome involves a number of findings, including insulin resistance, systemic hypertension, obesity, a proinflammatory state, and a prothrombotic state. Only one study addresses migraine in metabolic syndrome, finding significant differences in the presentation of metabolic syndrome in migraineurs. However, ...

  20. Metabolic Engineering X Conference

    Energy Technology Data Exchange (ETDEWEB)

    Flach, Evan [American Institute of Chemical Engineers

    2015-05-07

    The International Metabolic Engineering Society (IMES) and the Society for Biological Engineering (SBE), both technological communities of the American Institute of Chemical Engineers (AIChE), hosted the Metabolic Engineering X Conference (ME-X) on June 15-19, 2014 at the Westin Bayshore in Vancouver, British Columbia. It attracted 395 metabolic engineers from academia, industry and government from around the globe.

  1. Synthetic metabolism: metabolic engineering meets enzyme design.

    Science.gov (United States)

    Erb, Tobias J; Jones, Patrik R; Bar-Even, Arren

    2017-04-01

    Metabolic engineering aims at modifying the endogenous metabolic network of an organism to harness it for a useful biotechnological task, for example, production of a value-added compound. Several levels of metabolic engineering can be defined and are the topic of this review. Basic 'copy, paste and fine-tuning' approaches are limited to the structure of naturally existing pathways. 'Mix and match' approaches freely recombine the repertoire of existing enzymes to create synthetic metabolic networks that are able to outcompete naturally evolved pathways or redirect flux toward non-natural products. The space of possible metabolic solution can be further increased through approaches including 'new enzyme reactions', which are engineered on the basis of known enzyme mechanisms. Finally, by considering completely 'novel enzyme chemistries' with de novo enzyme design, the limits of nature can be breached to derive the most advanced form of synthetic pathways. We discuss the challenges and promises associated with these different metabolic engineering approaches and illuminate how enzyme engineering is expected to take a prime role in synthetic metabolic engineering for biotechnology, chemical industry and agriculture of the future. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds...... of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  3. Metabolism of ethynyl estrogens.

    Science.gov (United States)

    Helton, E D; Goldzieher, J W

    1977-09-01

    The pharmacokinetics and metabolic conversion of the ethynylated estrogens are reviewed. Special emphasis is given to the comparative pharmacokinetics of ethynyl-estradiol in different populations of women. Similarly, the variability of ethynyl-estradiol and mestranol metabolism in humans resulting from presentation of radio-labeled steroid and purification of the metabolic products is presented and discussed. The concepts of estrogen hepatotoxicity are reviewed with respect to the known phenomenon of estrogen oxidative metabolism and covalent binding. Recent evidence for the metabolic removal of the 17alpha-ethynyl group is discussed, and its relationship to estrogen hepatoxicity is considered and related to the covalent binding phenomenon.

  4. Integrative metabolic engineering

    Directory of Open Access Journals (Sweden)

    George H McArthur IV

    2015-07-01

    Full Text Available Recent advances in experimental and computational synthetic biology are extremely useful for achieving metabolic engineering objectives. The integration of synthetic biology and metabolic engineering within an iterative design-build-test framework will improve the practice of metabolic engineering by relying more on efficient design strategies. Computational tools that aid in the design and in silico simulation of metabolic pathways are especially useful. However, software helpful for constructing, implementing, measuring and characterizing engineered pathways and networks should not be overlooked. In this review, we highlight computational synthetic biology tools relevant to metabolic engineering, organized in the context of the design-build-test cycle.

  5. Systems Biology of Metabolism.

    Science.gov (United States)

    Nielsen, Jens

    2017-06-20

    Metabolism is highly complex and involves thousands of different connected reactions; it is therefore necessary to use mathematical models for holistic studies. The use of mathematical models in biology is referred to as systems biology. In this review, the principles of systems biology are described, and two different types of mathematical models used for studying metabolism are discussed: kinetic models and genome-scale metabolic models. The use of different omics technologies, including transcriptomics, proteomics, metabolomics, and fluxomics, for studying metabolism is presented. Finally, the application of systems biology for analyzing global regulatory structures, engineering the metabolism of cell factories, and analyzing human diseases is discussed.

  6. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation.......Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds...

  7. Metabolic syndrome and migraine

    Directory of Open Access Journals (Sweden)

    Amit eSachdev

    2012-11-01

    Full Text Available Migraine and metabolic syndrome are highly prevaleirnt and costly conditions.The two conditions coexist, but it is unclear what relationship may exist between the two processes. Metabolic syndrome involves a number of findings, including insulin resistance, systemic hypertension, obesity, a proinflammatory state, and a prothrombotic state. Only one study addresses migraine in metabolic syndrome, finding significant differences in the presentation of metabolic syndrome in migraineurs. However, controversy exists regarding the contribution of each individual risk factor to migraine pathogensis and prevalence. It is unclear what treatment implications, if any, exist as a result of the concomitant diagnosis of migraine and metabolic syndrome. The cornerstone of migraine and metabolic syndrome treatments is prevention, relying heavily on diet modification, sleep hygiene, medication use, and exercise.

  8. Migraine in metabolic syndrome.

    Science.gov (United States)

    Guldiken, Baburhan; Guldiken, Sibel; Taskiran, Bengur; Koc, Gonul; Turgut, Nilda; Kabayel, Levent; Tugrul, Armagan

    2009-03-01

    Recent studies suggest that insulin resistance is more common in patients with migraine. Insulin resistance underlies the pathogenesis of obesity, diabetes, and hypertension that are components of metabolic syndrome. As migraine is associated with an increased risk of vascular disorders, such as stroke, and migraine patients have higher diastolic blood pressure than healthy individuals, we aimed to investigate the 1-year prevalence of migraine in metabolic syndrome. Two hundred ten patients with metabolic syndrome were enrolled in the study. Migraine was diagnosed according to International Classification of Headache Disorders-II criteria. Migraine prevalence was estimated as 11.9% in men and 22.5% in women with metabolic syndrome. Of the metabolic syndrome components, diabetes, increased waist circumference, and body mass index were significantly more frequent in patients with migraine in contrast to those without migraine (Pmigraine prevalence in metabolic syndrome was higher than in the general population.

  9. Metabolic syndrome and migraine.

    Science.gov (United States)

    Sachdev, Amit; Marmura, Michael J

    2012-01-01

    Migraine and metabolic syndrome are highly prevalent and costly conditions. The two conditions coexist, but it is unclear what relationship may exist between the two processes. Metabolic syndrome involves a number of findings, including insulin resistance, systemic hypertension, obesity, a proinflammatory state, and a prothrombotic state. Only one study addresses migraine in metabolic syndrome, finding significant differences in the presentation of metabolic syndrome in migraineurs. However, controversy exists regarding the contribution of each individual risk factor to migraine pathogenesis and prevalence. It is unclear what treatment implications, if any, exist as a result of the concomitant diagnosis of migraine and metabolic syndrome. The cornerstone of migraine and metabolic syndrome treatments is prevention, relying heavily on diet modification, sleep hygiene, medication use, and exercise.

  10. [Menopause and metabolic syndrome].

    Science.gov (United States)

    Meirelles, Ricardo M R

    2014-03-01

    The incidence of cardiovascular disease increases considerably after the menopause. One reason for the increased cardiovascular risk seems to be determined by metabolic syndrome, in which all components (visceral obesity, dyslipidemia, hypertension, and glucose metabolism disorder) are associated with higher incidence of coronary artery disease. After menopause, metabolic syndrome is more prevalent than in premenopausal women, and may plays an important role in the occurrence of myocardial infarction and other atherosclerotic and cardiovascular morbidities. Obesity, an essential component of the metabolic syndrome, is also associated with increased incidence of breast, endometrial, bowel, esophagus, and kidney cancer. The treatment of metabolic syndrome is based on the change in lifestyle and, when necessary, the use of medication directed to its components. In the presence of symptoms of the climacteric syndrome, hormonal therapy, when indicated, will also contribute to the improvement of the metabolic syndrome.

  11. Transcriptional regulation of metabolism.

    Science.gov (United States)

    Desvergne, Béatrice; Michalik, Liliane; Wahli, Walter

    2006-04-01

    Our understanding of metabolism is undergoing a dramatic shift. Indeed, the efforts made towards elucidating the mechanisms controlling the major regulatory pathways are now being rewarded. At the molecular level, the crucial role of transcription factors is particularly well-illustrated by the link between alterations of their functions and the occurrence of major metabolic diseases. In addition, the possibility of manipulating the ligand-dependent activity of some of these transcription factors makes them attractive as therapeutic targets. The aim of this review is to summarize recent knowledge on the transcriptional control of metabolic homeostasis. We first review data on the transcriptional regulation of the intermediary metabolism, i.e., glucose, amino acid, lipid, and cholesterol metabolism. Then, we analyze how transcription factors integrate signals from various pathways to ensure homeostasis. One example of this coordination is the daily adaptation to the circadian fasting and feeding rhythm. This section also discusses the dysregulations causing the metabolic syndrome, which reveals the intricate nature of glucose and lipid metabolism and the role of the transcription factor PPARgamma in orchestrating this association. Finally, we discuss the molecular mechanisms underlying metabolic regulations, which provide new opportunities for treating complex metabolic disorders.

  12. Mathematical modelling of metabolism

    DEFF Research Database (Denmark)

    Gombert, Andreas Karoly; Nielsen, Jens

    2000-01-01

    Mathematical models of the cellular metabolism have a special interest within biotechnology. Many different kinds of commercially important products are derived from the cell factory, and metabolic engineering can be applied to improve existing production processes, as well as to make new processes...... availability of genomic information and powerful analytical techniques, mathematical models also serve as a tool for understanding the cellular metabolism and physiology....... available. Both stoichiometric and kinetic models have been used to investigate the metabolism, which has resulted in defining the optimal fermentation conditions, as well as in directing the genetic changes to be introduced in order to obtain a good producer strain or cell line. With the increasing...

  13. Eicosanoids in Metabolic Syndrome

    Science.gov (United States)

    Hardwick, James P.; Eckman, Katie; Lee, Yoon Kwang; Abdelmegeed, Mohamed A.; Esterle, Andrew; Chilian, William M.; Chiang, John Y.; Song, Byoung-Joon

    2013-01-01

    Chronic persistent inflammation plays a significant role in disease pathology of cancer, cardiovascular disease, and metabolic syndrome (MetS). MetS is a constellation of diseases that include obesity, diabetes, hypertension, dyslipidemia, hypertriglyceridemia, and hypercholesterolemia. Nonalcoholic fatty liver disease (NAFLD) is associated with many of the MetS diseases. These metabolic derangements trigger a persistent inflammatory cascade, which includes production of lipid autacoids (eicosanoids) that recruit immune cells to the site of injury and subsequent expression of cytokines and chemokines that amplify the inflammatory response. In acute inflammation, the transcellular synthesis of antiinflammatory eicosanoids resolve inflammation, while persistent activation of the autacoid-cytokine-chemokine cascade in metabolic disease leads to chronic inflammation and accompanying tissue pathology. Many drugs targeting the eicosanoid pathways have been shown to be effective in the treatment of MetS, suggesting a common linkage between inflammation, MetS and drug metabolism.The cross-talk between inflammation and MetS seems apparent because of the growing evidence linking immune cell activation and metabolic disorders such as insulin resistance, dyslipidemia, and hypertriglyceridemia. Thus modulation of lipid metabolism through either dietary adjustment or selective drugs may become a new paradigm in the treatment of metabolic disorders. This review focuses on the mechanisms linking eicosanoid metabolism to persistent inflammation and altered lipid and carbohydrate metabolism in MetS. PMID:23433458

  14. Fluoroacetylcarnitine: metabolism and metabolic effects in mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Bremer, J.; Davis, E.J.

    1973-01-01

    The metabolism and metabolic effects of fluoroacetylcarnitine have been investigated. Carnitineacetyltransferase transfers the fluoro-acetyl group of fluoroacetylcarnitine nearly as rapidly to CoA as the acetyl group of acetylcarnitine. Fluorocitrate is then formed by citrate synthase, but this second reaction is relatively slow. The fluorocitrate formed intramitochondrially inhibits the metabolism of citrate. In heart and skeletal muscle mitochondria the accumulated citrate inhibits citrate synthesis and the ..beta..-oxidation of fatty acids. Free acetate is formed, presumably because accumulated acetyl-CoA is hydrolyzed. In liver mitochondria the accumulation of citrate leads to a relatively increased rate of ketogenesis. Increased ketogenesis is obtained also upon the addition of citrate to the reaction mixture.

  15. Attractor metabolic networks.

    Science.gov (United States)

    De la Fuente, Ildefonso M; Cortes, Jesus M; Pelta, David A; Veguillas, Juan

    2013-01-01

    The experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a Systemic Metabolic Structure in the cell, characterized by a set of different enzymatic reactions always locked into active states (metabolic core) while the rest of the catalytic processes are only intermittently active. This global metabolic structure was verified for Escherichia coli, Helicobacter pylori and Saccharomyces cerevisiae, and it seems to be a common key feature to all cellular organisms. In concordance with these observations, the cell can be considered a complex metabolic network which mainly integrates a large ensemble of self-organized multienzymatic complexes interconnected by substrate fluxes and regulatory signals, where multiple autonomous oscillatory and quasi-stationary catalytic patterns simultaneously emerge. The network adjusts the internal metabolic activities to the external change by means of flux plasticity and structural plasticity. In order to research the systemic mechanisms involved in the regulation of the cellular enzymatic activity we have studied different catalytic activities of a dissipative metabolic network under different external stimuli. The emergent biochemical data have been analysed using statistical mechanic tools, studying some macroscopic properties such as the global information and the energy of the system. We have also obtained an equivalent Hopfield network using a Boltzmann machine. Our main result shows that the dissipative metabolic network can behave as an attractor metabolic network. We have found that the systemic enzymatic activities are governed by attractors with capacity to store functional metabolic patterns which can be correctly recovered from specific input stimuli. The network attractors regulate the catalytic patterns, modify the efficiency in the connection between the multienzymatic complexes, and stably

  16. Attractor metabolic networks.

    Directory of Open Access Journals (Sweden)

    Ildefonso M De la Fuente

    Full Text Available BACKGROUND: The experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a Systemic Metabolic Structure in the cell, characterized by a set of different enzymatic reactions always locked into active states (metabolic core while the rest of the catalytic processes are only intermittently active. This global metabolic structure was verified for Escherichia coli, Helicobacter pylori and Saccharomyces cerevisiae, and it seems to be a common key feature to all cellular organisms. In concordance with these observations, the cell can be considered a complex metabolic network which mainly integrates a large ensemble of self-organized multienzymatic complexes interconnected by substrate fluxes and regulatory signals, where multiple autonomous oscillatory and quasi-stationary catalytic patterns simultaneously emerge. The network adjusts the internal metabolic activities to the external change by means of flux plasticity and structural plasticity. METHODOLOGY/PRINCIPAL FINDINGS: In order to research the systemic mechanisms involved in the regulation of the cellular enzymatic activity we have studied different catalytic activities of a dissipative metabolic network under different external stimuli. The emergent biochemical data have been analysed using statistical mechanic tools, studying some macroscopic properties such as the global information and the energy of the system. We have also obtained an equivalent Hopfield network using a Boltzmann machine. Our main result shows that the dissipative metabolic network can behave as an attractor metabolic network. CONCLUSIONS/SIGNIFICANCE: We have found that the systemic enzymatic activities are governed by attractors with capacity to store functional metabolic patterns which can be correctly recovered from specific input stimuli. The network attractors regulate the catalytic patterns

  17. Metabolic regulation of inflammation.

    Science.gov (United States)

    Gaber, Timo; Strehl, Cindy; Buttgereit, Frank

    2017-05-01

    Immune cells constantly patrol the body via the bloodstream and migrate into multiple tissues where they face variable and sometimes demanding environmental conditions. Nutrient and oxygen availability can vary during homeostasis, and especially during the course of an immune response, creating a demand for immune cells that are highly metabolically dynamic. As an evolutionary response, immune cells have developed different metabolic programmes to supply them with cellular energy and biomolecules, enabling them to cope with changing and challenging metabolic conditions. In the past 5 years, it has become clear that cellular metabolism affects immune cell function and differentiation, and that disease-specific metabolic configurations might provide an explanation for the dysfunctional immune responses seen in rheumatic diseases. This Review outlines the metabolic challenges faced by immune cells in states of homeostasis and inflammation, as well as the variety of metabolic configurations utilized by immune cells during differentiation and activation. Changes in cellular metabolism that contribute towards the dysfunctional immune responses seen in rheumatic diseases are also briefly discussed.

  18. Metabolic syndrome and menopause

    Directory of Open Access Journals (Sweden)

    Jouyandeh Zahra

    2013-01-01

    Full Text Available Abstract Background The metabolic syndrome is defined as an assemblage of risk factors for cardiovascular diseases, and menopause is associated with an increase in metabolic syndrome prevalence. The aim of this study was to assess the prevalence of metabolic syndrome and its components among postmenopausal women in Tehran, Iran. Methods In this cross-sectional study in menopause clinic in Tehran, 118 postmenopausal women were investigated. We used the adult treatment panel 3 (ATP3 criteria to classify subjects as having metabolic syndrome. Results Total prevalence of metabolic syndrome among our subjects was 30.1%. Waist circumference, HDL-cholesterol, fasting blood glucose, diastolic blood pressure ,Systolic blood pressure, and triglyceride were significantly higher among women with metabolic syndrome (P-value Conclusions Our study shows that postmenopausal status is associated with an increased risk of metabolic syndrome. Therefore, to prevent cardiovascular disease there is a need to evaluate metabolic syndrome and its components from the time of the menopause.

  19. Adaptation of a mixed culture of acidophiles for a tank biooxidation of refractory gold concentrates containing a high concentration of arsenic.

    Science.gov (United States)

    Hong, Jeongsik; Silva, Rene A; Park, Jeonghyun; Lee, Eunseong; Park, Jayhyun; Kim, Hyunjung

    2016-05-01

    We adapted a mixed culture of acidophiles to high arsenic concentrations to confirm the possibility of achieving more than 70% biooxidation of refractory gold concentrates containing high arsenic (As) concentration. The biooxidation process was applied to refractory gold concentrates containing approximately 139.67 g/kg of total As in a stirred tank reactor using an adapted mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The percentage of the biooxidation process was analyzed based on the total As removal efficiency. The As removal was monitored by inductively coupled plasma (ICP) analysis, conducted every 24 h. The results obtained with the adapted culture were compared with the percentage of biooxidation obtained with a non-adapted mixed culture of A. ferrooxidans and A. thiooxidans, and with their respective pure cultures. The percentages of biooxidation obtained during 358 h of reaction were 72.20%, 38.20%, 27.70%, and 11.45% for adapted culture, non-adapted culture, and pure cultures of A. thiooxidans and A. ferrooxidans, respectively. The adapted culture showed a peak maximum percentage of biooxidation of 77% at 120 h of reaction, confirming that it is possible to obtain biooxidation percentages over 70% in gold concentrates containing high As concentrations. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Mycobacterium tuberculosis Metabolism

    Science.gov (United States)

    Warner, Digby F.

    2015-01-01

    Metabolism underpins the physiology and pathogenesis of Mycobacterium tuberculosis. However, although experimental mycobacteriology has provided key insights into the metabolic pathways that are essential for survival and pathogenesis, determining the metabolic status of bacilli during different stages of infection and in different cellular compartments remains challenging. Recent advances—in particular, the development of systems biology tools such as metabolomics—have enabled key insights into the biochemical state of M. tuberculosis in experimental models of infection. In addition, their use to elucidate mechanisms of action of new and existing antituberculosis drugs is critical for the development of improved interventions to counter tuberculosis. This review provides a broad summary of mycobacterial metabolism, highlighting the adaptation of M. tuberculosis as specialist human pathogen, and discusses recent insights into the strategies used by the host and infecting bacillus to influence the outcomes of the host–pathogen interaction through modulation of metabolic functions. PMID:25502746

  1. Metabolic Engineering VII Conference

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Korpics

    2012-12-04

    The aims of this Metabolic Engineering conference are to provide a forum for academic and industrial researchers in the field; to bring together the different scientific disciplines that contribute to the design, analysis and optimization of metabolic pathways; and to explore the role of Metabolic Engineering in the areas of health and sustainability. Presentations, both written and oral, panel discussions, and workshops will focus on both applications and techniques used for pathway engineering. Various applications including bioenergy, industrial chemicals and materials, drug targets, health, agriculture, and nutrition will be discussed. Workshops focused on technology development for mathematical and experimental techniques important for metabolic engineering applications will be held for more in depth discussion. This 2008 meeting will celebrate our conference tradition of high quality and relevance to both industrial and academic participants, with topics ranging from the frontiers of fundamental science to the practical aspects of metabolic engineering.

  2. Glycogen metabolism in cancer.

    Science.gov (United States)

    Zois, Christos E; Favaro, Elena; Harris, Adrian L

    2014-11-01

    Since its identification more than 150 years ago, there has been an extensive characterisation of glycogen metabolism and its regulatory pathways in the two main glycogen storage organs of the body, i.e. liver and muscle. In recent years, glycogen metabolism has also been demonstrated to be upregulated in many tumour types, suggesting it is an important aspect of cancer cell pathophysiology. Here, we provide an overview of glycogen metabolism and its regulation, with a focus on its role in metabolic reprogramming of cancer cells. The various methods to detect glycogen in tumours in vivo are also reviewed. Finally, we discuss the targeting of glycogen metabolism as a strategy for cancer treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Metabolic imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Takashi [University of Fukui, Biomedical Imaging Research Center, Eiheiji-cho, Fukui (Japan)

    2007-06-15

    There is growing evidence that myocardial metabolism plays a key role not only in ischaemic heart disease but also in a variety of diseases which involve myocardium globally, such as heart failure and diabetes mellitus. Understanding myocardial metabolism in such diseases helps to elucidate the pathophysiology and assists in making therapeutic decisions. As well as providing information on regional changes, PET can deliver quantitative information about both regional and global changes in metabolism. This capability of quantitative measurement is one of the major advantages of PET along with physiological positron tracers, especially relevant in evaluating diseases which involve the whole myocardium. This review discusses major PET tracers for metabolic imaging and their clinical applications and contributions to research regarding ischaemic heart disease and other diseases such as heart failure and diabetic heart disease. Future applications of positron metabolic tracers for the detection of vulnerable plaque are also highlighted briefly. (orig.)

  4. [Psychopharmacology and metabolic syndrome].

    Science.gov (United States)

    Telles-Correia, Diogo; Guerreiro, Diogo F; Coentre, Ricardo; Coentre, Rui; Góis, C; Figueira, Luísa

    2008-01-01

    Metabolic Syndrome consists in a group of metabolic changes, being the most important problem insulin resistence. Other important components of this syndrome are abdominal obesity, hypertension and hyperlipidemia /hypercholestrolemia. It was demonstrated that psychiatric patients have a greater risk to develop metabolic syndrome with a prevalence of 41%. Prevalence of this syndrome in psychiatric male patients is 138% higher than in general population and in female patients 251% higher. Some of the factors that can explain this increase of metabolic risk in psychiatric patients are psychiatric drugs. We preformed a systematic review of literature published until June, 2007, by means of MEDLINE. Studies reviewed include clinical cases, reviews, analytic and observational studies. We selected 72 articles. Authors pretend to understand the mechanisms, by which, different psychiatric drugs can influence metabolic syndrome, and strategies for prevention of this situation.

  5. Metabolic disorders in menopause

    Directory of Open Access Journals (Sweden)

    Grzegorz Stachowiak

    2015-04-01

    Full Text Available Metabolic disorders occurring in menopause, including dyslipidemia, disorders of carbohydrate metabolism (impaired glucose tolerance – IGT, type 2 diabetes mellitus – T2DM or components of metabolic syndrome, constitute risk factors for cardiovascular disease in women. A key role could be played here by hyperinsulinemia, insulin resistance and visceral obesity, all contributing to dyslipidemia, oxidative stress, inflammation, alter coagulation and atherosclerosis observed during the menopausal period. Undiagnosed and untreated, metabolic disorders may adversely affect the length and quality of women’s life. Prevention and treatment preceded by early diagnosis should be the main goal for the physicians involved in menopausal care. This article represents a short review of the current knowledge concerning metabolic disorders (e.g. obesity, polycystic ovary syndrome or thyroid diseases in menopause, including the role of a tailored menopausal hormone therapy (HT. According to current data, HT is not recommend as a preventive strategy for metabolic disorders in menopause. Nevertheless, as part of a comprehensive strategy to prevent chronic diseases after menopause, menopausal hormone therapy, particularly estrogen therapy may be considered (after balancing benefits/risks and excluding women with absolute contraindications to this therapy. Life-style modifications, with moderate physical activity and healthy diet at the forefront, should be still the first choice recommendation for all patients with menopausal metabolic abnormalities.

  6. Personality and metabolic syndrome.

    Science.gov (United States)

    Sutin, Angelina R; Costa, Paul T; Uda, Manuela; Ferrucci, Luigi; Schlessinger, David; Terracciano, Antonio

    2010-12-01

    The prevalence of metabolic syndrome has paralleled the sharp increase in obesity. Given its tremendous physical, emotional, and financial burden, it is of critical importance to identify who is most at risk and the potential points of intervention. Psychological traits, in addition to physiological and social risk factors, may contribute to metabolic syndrome. The objective of the present research is to test whether personality traits are associated with metabolic syndrome in a large community sample. Participants (N = 5,662) from Sardinia, Italy, completed a comprehensive personality questionnaire, the NEO-PI-R, and were assessed on all components of metabolic syndrome (waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose). Logistic regressions were used to predict metabolic syndrome from personality traits, controlling for age, sex, education, and current smoking status. Among adults over age 45 (n = 2,419), Neuroticism and low Agreeableness were associated with metabolic syndrome, whereas high Conscientiousness was protective. Individuals who scored in the top 10% on Conscientiousness were approximately 40% less likely to have metabolic syndrome (OR = 0.61, 95% CI = 0.41-0.92), whereas those who scored in the lowest 10% on Agreeableness were 50% more likely to have it (OR = 1.53, 95% CI = 1.09-2.16). At the facet level, traits related to impulsivity and hostility were the most strongly associated with metabolic syndrome. The present research indicates that those with fewer psychological resources are more vulnerable to metabolic syndrome and suggests a psychological component to other established risk factors.

  7. Human Body Exergy Metabolism

    OpenAIRE

    Mady, Carlos

    2013-01-01

    The exergy analysis of the human body is a tool that can provide indicators of health and life quality. To perform the exergy balance it is necessary to calculate the metabolism on an exergy basis, or metabolic exergy, although there is not yet consensus in its calculation procedure. Hence, the aim of this work is to provide a general method to evaluate this physical quantity for human body based on indirect calorimetry data. To calculate the metabolism on an exergy basis it is necessary to d...

  8. A Metabolic Switch

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    Our muscles are metabolically flexible, i.e., they are capable of `switching' between two types of oxidation: (1) when fasting, a predominantly lipid oxidation with high rates of fatty acid uptake, and (2) when fed, suppression of lipid oxidation in favour of increased glucose uptake, oxidation...... and storage, in response to insulin. One of the many manifestations of obesity and Type 2 diabetes is an insulin resistance of the skeletal muscles, which suppresses this metabolic switch. This talk describes recent development of a low-dimensional system of ODEs that model the metabolic switch, displaying...

  9. Migraine and metabolism.

    Science.gov (United States)

    Casucci, G; Villani, V; Cologno, D; D'Onofrio, F

    2012-05-01

    Migraine is a chronic disorder with complex pathophysiology involving both neuronal and vascular mechanisms. Migraine is associated with an increased risk of vascular disorders, such as stroke and coronary heart disease. Obesity and diabetes are metabolic disorders with a complex association with migraine. Insulin resistance, which represents the main causal factor of diseases involved in metabolic syndrome, is more common in patients with migraine. A better understanding of the relationship between metabolic syndrome and migraine may be of great clinical interest for migraine management.

  10. What is Nutrition & Metabolism?

    Directory of Open Access Journals (Sweden)

    Feinman Richard D

    2004-08-01

    Full Text Available Abstract A new Open Access journal, Nutrition & Metabolism (N&M will publish articles that integrate nutrition with biochemistry and molecular biology. The open access process is chosen to provide rapid and accessible dissemination of new results and perspectives in a field that is of great current interest. Manuscripts in all areas of nutritional biochemistry will be considered but three areas of particular interest are lipoprotein metabolism, amino acids as metabolic signals, and the effect of macronutrient composition of diet on health. The need for the journal is identified in the epidemic of obesity, diabetes, dyslipidemias and related diseases, and a sudden increase in popular diets, as well as renewed interest in intermediary metabolism.

  11. Metabolic Imaging of Infection

    NARCIS (Netherlands)

    Lawal, Ismaheel; Zeevaart, JanRijn; Ebenhan, Thomas; Ankrah, Alfred; Vorster, Mariza; Kruger, Hendrik G.; Govender, Thavendran; Sathekge, Mike

    2017-01-01

    Metabolic imaging has come to occupy a prominent place in the diagnosis and management of microbial infection. Molecular probes available for infection imaging have undergone a rapid evolution starting with nonspecific agents that accumulate similarly in infection, sterile inflammation, and

  12. Metabolism. Part III: Lipids.

    Science.gov (United States)

    Bodner, George M.

    1986-01-01

    Describes the metabolic processes of complex lipids, including saponification, activation and transport, and the beta-oxidation spiral. Discusses fatty acid degradation in regard to biochemical energy and ketone bodies. (TW)

  13. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... this process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form ...

  14. Epigenetics and Cellular Metabolism

    Directory of Open Access Journals (Sweden)

    Wenyi Xu

    2016-01-01

    Full Text Available Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc. is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well.

  15. Engineering of metabolic control

    Science.gov (United States)

    Liao, James C.

    2004-03-16

    The invention features a method of producing heterologous molecules in cells under the regulatory control of a metabolite and metabolic flux. The method can enhance the synthesis of heterologous polypeptides and metabolites.

  16. Diphosphoinositol Polyphosphates: Metabolic Messengers?

    Science.gov (United States)

    Shears, Stephen B.

    2009-01-01

    The diphosphoinositol polyphosphates (“inositol pyrophosphates”) are a specialized subgroup of the inositol phosphate signaling family. This review proposes that many of the current data concerning the metabolic turnover and biological effects of the diphosphoinositol polyphosphates are linked by a common theme: these polyphosphates act as metabolic messengers. This review will also discuss the latest proposals concerning possible molecular mechanisms of action of this intriguing class of molecules. PMID:19439500

  17. Metabolic Theory: Energetic barriers

    OpenAIRE

    Locey, Kenneth

    2013-01-01

    This is an early talk I gave on a possible refinement to the metabolic theory of ecology (MTE). In short, the basic equation of MTE uses an Arrhenius-like formula (which in turn assumes a constant activation energy) to predict how metabolic related rates and species richness should vary with temperature. Here, I proposed that the simple Arrhenius relationship could be replaced with a more dynamical relationship where activation energy could be predicted to change, as is often observed in biol...

  18. Tobacco and metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Yatan Pal Singh Balhara

    2012-01-01

    Full Text Available Tobacco is a leading contributor to morbidity and mortality globally. Metabolic syndrome is a constellation of abdominal obesity, atherogenic dyslipidemia, raised blood pressure, insulin resistance (with and without glucose intolerance, pro-inflammatory state, and pro-thrombotic state. Tobacco use is associated with various core components of metabolic syndrome. It has been found to play a causal role in various pathways leading on to development this condition, the current article discusses various facets of this association.

  19. Primary Metabolic Pathways and Metabolic Flux Analysis

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    his chapter introduces the metabolic flux analysis (MFA) or stoichiometry-based MFA, and describes the quantitative basis for MFA. It discusses the catabolic pathways in which free energy is produced to drive the cell-building anabolic pathways. An overview of these primary pathways provides...... to be examined in the following are: glycolysis, primarily by the EMP pathway, but other glycolytic pathways is also mentioned; fermentative pathways in which the redox generated in the glycolytic reactions are consumed; reactions in the tricarboxylic acid (TCA) cycle, which produce biomass precursors and redox...

  20. Apelin and energy metabolism

    Directory of Open Access Journals (Sweden)

    Chantal eBertrand

    2015-04-01

    Full Text Available A wide range of adipokines identified over the past years has allowed considering white adipose tissue as a secretory organ closely integrated into overall physiological and metabolic control. Apelin, an ubiquitous peptide was known to exert different physiological effects mainly on the cardiovascular system and the regulation of fluid homeostasis until its identification as an adipokine. This has increased its broad range of action and apelin now appears clearly as a new player in energy metabolism alongside leptin and adiponectin. Apelin has been shown to act on glucose and lipid metabolism but also to modulate insulin secretion. Moreover, different studies in both animals and humans have shown that plasma apelin concentrations are usually increased during obesity and type 2 diabetes. This mini-review will focus on the various systemic apelin effects on energy metabolism by addressing its mechanisms of action. The advances concerning the role of apelin in metabolic diseases in relation with the recent reports on apelin concentrations in obese and/or diabetic subjects will also be discussed.

  1. Metabolic surgery: quo vadis?

    Science.gov (United States)

    Ramos-Leví, Ana M; Rubio Herrera, Miguel A

    2014-01-01

    The impact of bariatric surgery beyond its effect on weight loss has entailed a change in the way of regarding it. The term metabolic surgery has become more popular to designate those interventions that aim at resolving diseases that have been traditionally considered as of exclusive medical management, such as type 2 diabetes mellitus (T2D). Recommendations for metabolic surgery have been largely addressed and discussed in worldwide meetings, but no definitive consensus has been reached yet. Rates of diabetes remission after metabolic surgery have been one of the most debated hot topics, with heterogeneity being a current concern. This review aims to identify and clarify controversies regarding metabolic surgery, by focusing on a critical analysis of T2D remission rates achieved with different bariatric procedures, and using different criteria for its definition. Indications for metabolic surgery for patients with T2D who are not morbidly obese are also discussed. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

  2. Dysregulated metabolic enzymes and metabolic reprogramming in cancer cells.

    Science.gov (United States)

    Sreedhar, Annapoorna; Zhao, Yunfeng

    2018-01-01

    Tumor cells carry various genetic and metabolic alterations, which directly contribute to their growth and malignancy. Links between metabolism and cancer are multifaceted. Metabolic reprogramming, such as enhanced aerobic glycolysis, mutations in the tricarboxylic acid (TCA) cycle metabolic enzymes, and dependence on lipid and glutamine metabolism are key characteristics of cancer cells. Understanding these metabolic alterations is crucial for development of novel anti-cancer therapeutic strategies. In the present review, the broad importance of metabolism in tumor biology is discussed, and the current knowledge on dysregulated metabolic enzymes involved in the vital regulatory steps of glycolysis, the TCA cycle, the pentose phosphate pathway, and lipid, amino acid, and mitochondrial metabolism pathways are reviewed.

  3. Monitoring Acidophilic Microbes with Real-Time Polymerase Chain Reaction (PCR) Assays

    Energy Technology Data Exchange (ETDEWEB)

    Frank F. Roberto

    2008-08-01

    Many techniques that are used to characterize and monitor microbial populations associated with sulfide mineral bioleaching require the cultivation of the organisms on solid or liquid media. Chemolithotrophic species, such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, or thermophilic chemolithotrophs, such as Acidianus brierleyi and Sulfolobus solfataricus can grow quite slowly, requiring weeks to complete efforts to identify and quantify these microbes associated with bioleach samples. Real-time PCR (polymerase chain reaction) assays in which DNA targets are amplified in the presence of fluorescent oligonucleotide primers, allowing the monitoring and quantification of the amplification reactions as they progress, provide a means of rapidly detecting the presence of microbial species of interest, and their relative abundance in a sample. This presentation will describe the design and use of such assays to monitor acidophilic microbes in the environment and in bioleaching operations. These assays provide results within 2-3 hours, and can detect less than 100 individual microbial cells.

  4. Urea metabolism in plants.

    Science.gov (United States)

    Witte, Claus-Peter

    2011-03-01

    Urea is a plant metabolite derived either from root uptake or from catabolism of arginine by arginase. In agriculture, urea is intensively used as a nitrogen fertilizer. Urea nitrogen enters the plant either directly, or in the form of ammonium or nitrate after urea degradation by soil microbes. In recent years various molecular players of plant urea metabolism have been investigated: active and passive urea transporters, the nickel metalloenzyme urease catalyzing the hydrolysis of urea, and three urease accessory proteins involved in the complex activation of urease. The degradation of ureides derived from purine breakdown has long been discussed as a possible additional metabolic source for urea, but an enzymatic route for the complete hydrolysis of ureides without a urea intermediate has recently been described for Arabidopsis thaliana. This review focuses on the proteins involved in plant urea metabolism and the metabolic sources of urea but also addresses open questions regarding plant urea metabolism in a physiological and agricultural context. The contribution of plant urea uptake and metabolism to fertilizer urea usage in crop production is still not investigated although globally more than half of all nitrogen fertilizer is applied to crops in the form of urea. Nitrogen use efficiency in crop production is generally well below 50% resulting in economical losses and creating ecological problems like groundwater pollution and emission of nitric oxides that can damage the ozone layer and function as greenhouse gasses. Biotechnological approaches to improve fertilizer urea usage bear the potential to increase crop nitrogen use efficiency. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  5. Nitrile Metabolizing Yeasts

    Science.gov (United States)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  6. Synthetic Metabolic Pathways

    DEFF Research Database (Denmark)

    This volume outlines key steps associated with the design, building, and testing of synthetic metabolic pathways for optimal cell factory performance and robustness, and illustrates how data-driven learning from these steps can be used for rational cost-effective engineering of cell factories...... topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Synthetic Metabolic Pathways: Methods and Protocols aims to ensure successful results in the further study...

  7. Metabolic Instruction of Immunity.

    Science.gov (United States)

    Buck, Michael D; Sowell, Ryan T; Kaech, Susan M; Pearce, Erika L

    2017-05-04

    Choices have consequences. Immune cells survey and migrate throughout the body and sometimes take residence in niche environments with distinct communities of cells, extracellular matrix, and nutrients that may differ from those in which they matured. Imbedded in immune cell physiology are metabolic pathways and metabolites that not only provide energy and substrates for growth and survival, but also instruct effector functions, differentiation, and gene expression. This review of immunometabolism will reference the most recent literature to cover the choices that environments impose on the metabolism and function of immune cells and highlight their consequences during homeostasis and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

    Science.gov (United States)

    Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

    2013-10-01

    Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

  9. Identificación molecular de microorganismos acidófilos en un tanque industrial de biooxidación de arsenopirita para la recuperación de oro

    OpenAIRE

    Quintana, Milagros; Ly, Martha; Montoya,Ysabel; Bauer, José; Espinoza, José; Espinoza, Marco

    2007-01-01

    En el presente trabajo, mediante amplificación por PCR del gen 16S rRNA bacteriano, se ha logrado identificar a los principales microorganismos quimiolitótrofos, acidófilos y biooxidantes de hierro y sulfuros que participan en la biooxidación de arsenopirita en un tanque industrial de la mina Tamboraque (Huarochirí, Lima) así como en el drenaje ácido de la misma mina. Los microorganismos reconocidos en el tanque industrial de biooxidación fueron: Acidithiobacillus ferrooxidans, Leptospirillum...

  10. Escalado de un proceso de biooxidación de residuos de minería ricos en sulfuros usando reactores de tanque agitado

    OpenAIRE

    Muñoz Echeverri, Laura María

    2015-01-01

    Resumen: En este trabajo se presenta el escalado y evaluación del proceso de biooxidación de un residuo de minería aurífera (proveniente de la mina La Maruja, Marmato-Caldas), desde una escala de laboratorio hasta un nivel de planta piloto en reactores de tanque agitado. Para procurar el éxito del escalado, se realizó una caracterización mineralógica inicial del residuo y una adaptación del agente biológico, Acidithiobacillus ferrooxidans, al mineral. A escala de laboratorio se determinó el n...

  11. Metabolism at Evolutionary Optimal States

    Directory of Open Access Journals (Sweden)

    Iraes Rabbers

    2015-06-01

    Full Text Available Metabolism is generally required for cellular maintenance and for the generation of offspring under conditions that support growth. The rates, yields (efficiencies, adaptation time and robustness of metabolism are therefore key determinants of cellular fitness. For biotechnological applications and our understanding of the evolution of metabolism, it is necessary to figure out how the functional system properties of metabolism can be optimized, via adjustments of the kinetics and expression of enzymes, and by rewiring metabolism. The trade-offs that can occur during such optimizations then indicate fundamental limits to evolutionary innovations and bioengineering. In this paper, we review several theoretical and experimental findings about mechanisms for metabolic optimization.

  12. Sleep and Metabolism: An Overview

    Directory of Open Access Journals (Sweden)

    Sunil Sharma

    2010-01-01

    Full Text Available Sleep and its disorders are increasingly becoming important in our sleep deprived society. Sleep is intricately connected to various hormonal and metabolic processes in the body and is important in maintaining metabolic homeostasis. Research shows that sleep deprivation and sleep disorders may have profound metabolic and cardiovascular implications. Sleep deprivation, sleep disordered breathing, and circadian misalignment are believed to cause metabolic dysregulation through myriad pathways involving sympathetic overstimulation, hormonal imbalance, and subclinical inflammation. This paper reviews sleep and metabolism, and how sleep deprivation and sleep disorders may be altering human metabolism.

  13. Macrophage Polarization in Metabolism and Metabolic Disease

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2013-08-01

    Full Text Available BACKGROUND: Obesity is now recognized as the main cause of the worldwide epidemic of type 2 diabetes. Obesity-associated chronic inflammation is a contributing key factor for type 2 diabetes and cardiovascular disease. Numbers of studies have clearly demonstrated that the immune system and metabolism are highly integrated. CONTENT: Macrophages are an essential component of innate immunity and play a central role in inflammation and host defense. Moreover, these cells have homeostatic functions beyond defense, including tissue remodeling in ontogenesis and orchestration of metabolic functions. Diversity and plasticity are hallmarks of cells of the monocyte-macrophage lineage. In response to interferons (IFNs, toll-like receptor (TLR, or interleukin (IL-4/IL-13 signals, macrophages undergo M1 (classical or M2 (alternative activation. Progress has now been made in defining the signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1, M2 or M2-like polarized activation. SUMMARY: In response to various signals, macrophages may undergo classical M1 activation (stimulated by TLR ligands and IFN-γ or alternative M2 activation (stimulated by IL-4/IL-13; these states mirror the T helper (Th1–Th2 polarization of T cells. Pathology is frequently associated with dynamic changes in macrophage activation, with classically activated M1 cells implicate in initiating and sustaining inflammation, meanwhile M2 or M2-like activated cells associated with resolution or smoldering chronic inflammation. Identification of the mechanisms and molecules that are associated with macrophage plasticity and polarized activation provides a basis for macrophage centered diagnostic and therapeutic strategies. KEYWORDS: obesity, adipose tissue, inflammation, macrophage polarization.

  14. Metabolism of antiarrhythmics.

    Science.gov (United States)

    Ha, Huy Riem; Follath, Ferenc

    2004-12-01

    Antiarrhythmics are a group of drugs that manage the irregular electrical activity of the heart. Their use in the clinic is made difficult by their narrow therapeutic index. The disposition of antiarrhythmics is dependent on many factors, such as administration route, stereoselectivity in the first-pass effect, inhibition of enzymes, polymorphisms, etc. Consequently, the pharmacological activity of drugs may be interindividually variable. Experiments using organ homogenates or hepatic microsome fractions were used for simulating the biotransformation of the drug in vivo. The classical approaches, such as correlation analysis, specifically the inhibitory effect, or induction of chemicals, and immunoinhibition, may be combined with the use of recombinant enzymes for identifying the enzymes involved in the drug metabolism. The fate of the antiarrhythmics may also be investigated in live animals. A species-dependent metabolism was often observed. The pre-treatment with chemicals, which influences the change (inhibition or induction) in the drug disposition, may provide insights into the enzymes involved in vivo. However, published data indicated that the data obtained from animals should not be extrapolated directly to humans. Nevertheless, animal models are useful for investigating the mechanism of clinical observations. The clinical use of the antiarrhythmics becomes complex, when the drug metabolism is genetically/phenotypically dependent and active metabolites are formed. Furthermore, the stereoselectivity may also modify the disposition and the pharmacodynamic profile of a therapeutic agent. Only the knowledge of the drug metabolism and the status of each individual may allow the use of antiarrhythmics safely.

  15. Diversified glucosinolate metabolism

    DEFF Research Database (Denmark)

    Frisch, Tina; Motawie, Mohammed Saddik; Olsen, Carl Erik

    2015-01-01

    were biosynthesized from methionine. The biosynthesis of alliarinoside was shown not to bifurcate from sinigrin biosynthesis at the oxime level in contrast to the general scheme for hydroxynitrile glucoside biosynthesis. Instead, the aglucon of alliarinoside was formed from metabolism of sinigrin...

  16. Thyroid and lipid metabolism.

    Science.gov (United States)

    Pucci, E; Chiovato, L; Pinchera, A

    2000-06-01

    Thyroid hormones influence all major metabolic pathways. Their most obvious and well-known action is an increase in basal energy expenditure obtained acting on protein, carbohydrate and lipid metabolism. With specific regard to lipid metabolism, thyroid hormones affect synthesis, mobilization and degradation of lipids, although degradation is influenced more than synthesis. The main and best-known effects on lipid metabolism include: (a) enhanced utilization of lipid substrates; (b) increase in the synthesis and mobilization of triglycerides stored in adipose tissue; (c) increase in the concentration of non-esterified fatty acids (NEFA); and (d) increase of lipoprotein-lipase activity. While severe hypothyroidism is usually associated with an increased serum concentration of total cholesterol and atherogenic lipoproteins, the occurrence of acute myocardial infarction (AMI) in hypothyroid patients is not frequent. However, hypothyroid patients appear to have an increased incidence of residual myocardial ischemia following AMI. Even in subclinical hypothyroidism, which is characterized by raised serum TSH levels with normal serum thyroid hormone concentrations, mild hyperlipidemia is present and may contribute to an increased risk of atherogenesis. Prudent substitution therapy with L-thyroxine is indicated in patients with both overt and subclinical hypothyroidism, with or without angina, to counteract the cardiovascular risk resulting from hyper-dyslipidemia.

  17. Metabolic Diseases of Muscle

    Science.gov (United States)

    ... ing fuel, and no energy is produced for muscle function. 4 Metabolic Diseases of Muscle • ©2011 MDA A ... This slowly progressive disorder causes cardiac disease and muscle weakness in the hips, shoulders, and upper arms and legs. The neck and ...

  18. Ghrelin and Metabolic Surgery

    Directory of Open Access Journals (Sweden)

    Dimitrios J. Pournaras

    2010-01-01

    Full Text Available Metabolic surgery is the most effective treatment for morbid obesity. Ghrelin has been implicated to play a role in the success of these procedures. Furthermore, these operations have been used to study the gut-brain axis. This article explores this interaction, reviewing the available data on changes in ghrelin levels after different surgical procedures.

  19. Neonatal nutrition and metabolism

    National Research Council Canada - National Science Library

    Thureen, Patti J; Hay, William W

    2006-01-01

    ..., the volume highlights the important longterm effects of fetal and neonatal growth on health in later life. In addition, there are very practical chapters on methods and techniques for assessing nutritional status, body composition, and evaluating metabolic function. Written by an authoritative, international team of cont...

  20. Metabolic Reprogramming in Glioma

    Science.gov (United States)

    Strickland, Marie; Stoll, Elizabeth A.

    2017-01-01

    Many cancers have long been thought to primarily metabolize glucose for energy production—a phenomenon known as the Warburg Effect, after the classic studies of Otto Warburg in the early twentieth century. Yet cancer cells also utilize other substrates, such as amino acids and fatty acids, to produce raw materials for cellular maintenance and energetic currency to accomplish cellular tasks. The contribution of these substrates is increasingly appreciated in the context of glioma, the most common form of malignant brain tumor. Multiple catabolic pathways are used for energy production within glioma cells, and are linked in many ways to anabolic pathways supporting cellular function. For example: glycolysis both supports energy production and provides carbon skeletons for the synthesis of nucleic acids; meanwhile fatty acids are used both as energetic substrates and as raw materials for lipid membranes. Furthermore, bio-energetic pathways are connected to pro-oncogenic signaling within glioma cells. For example: AMPK signaling links catabolism with cell cycle progression; mTOR signaling contributes to metabolic flexibility and cancer cell survival; the electron transport chain produces ATP and reactive oxygen species (ROS) which act as signaling molecules; Hypoxia Inducible Factors (HIFs) mediate interactions with cells and vasculature within the tumor environment. Mutations in the tumor suppressor p53, and the tricarboxylic acid cycle enzymes Isocitrate Dehydrogenase 1 and 2 have been implicated in oncogenic signaling as well as establishing metabolic phenotypes in genetically-defined subsets of malignant glioma. These pathways critically contribute to tumor biology. The aim of this review is two-fold. Firstly, we present the current state of knowledge regarding the metabolic strategies employed by malignant glioma cells, including aerobic glycolysis; the pentose phosphate pathway; one-carbon metabolism; the tricarboxylic acid cycle, which is central to amino acid

  1. Dysregulated metabolism contributes to oncogenesis

    Science.gov (United States)

    Hirschey, Matthew D.; DeBerardinis, Ralph J.; Diehl, Anna Mae E.; Drew, Janice E.; Frezza, Christian; Green, Michelle F.; Jones, Lee W.; Ko, Young H.; Le, Anne; Lea, Michael A.; Locasale, Jason W.; Longo, Valter D.; Lyssiotis, Costas A.; McDonnell, Eoin; Mehrmohamadi, Mahya; Michelotti, Gregory; Muralidhar, Vinayak; Murphy, Michael P.; Pedersen, Peter L.; Poore, Brad; Raffaghello, Lizzia; Rathmell, Jeffrey C.; Sivanand, Sharanya; Vander Heiden, Matthew G.; Wellen, Kathryn E.

    2015-01-01

    Cancer is a disease characterized by unrestrained cellular proliferation. In order to sustain growth, cancer cells undergo a complex metabolic rearrangement characterized by changes in metabolic pathways involved in energy production and biosynthetic processes. The relevance of the metabolic transformation of cancer cells has been recently included in the updated version of the review “Hallmarks of Cancer”, where the dysregulation of cellular metabolism was included as an emerging hallmark. While several lines of evidence suggest that metabolic rewiring is orchestrated by the concerted action of oncogenes and tumor suppressor genes, in some circumstances altered metabolism can play a primary role in oncogenesis. Recently, mutations of cytosolic and mitochondrial enzymes involved in key metabolic pathways have been associated with hereditary and sporadic forms of cancer. Together, these results suggest that aberrant metabolism, once seen just as an epiphenomenon of oncogenic reprogramming, plays a key role in oncogenesis with the power to control both genetic and epigenetic events in cells. In this review, we discuss the relationship between metabolism and cancer, as part of a larger effort to identify a broad-spectrum of therapeutic approaches. We focus on major alterations in nutrient metabolism and the emerging link between metabolism and epigenetics. Finally, we discuss potential strategies to manipulate metabolism in cancer and tradeoffs that should be considered. More research on the suite of metabolic alterations in cancer holds the potential to discover novel approaches to treat it. PMID:26454069

  2. A Metabolic Race

    Directory of Open Access Journals (Sweden)

    A.M.S. Costa et al.

    2017-07-01

    Full Text Available Metabolic Syndrome describes a set of metabolic risk factors that manifest in an individual and some aspects contribute to its appearance: genetic, overweight and the absence of physical activity. So, a board game was created to simulate the environment and routine experienced by UFF students that could contribute  to the development of Metabolic Syndrome. Players move along a simplified map of Niterói city, where places as Antônio Pedro Hospital (HUAP are pointed out. OBJECTIVES: This project aimed to develop an educational game to consolidate Metabolic Syndrome biochemical events. MATERIAL E METHODS: Each group receives a board, pins, dice, question, challenge and diagnostics cards. One student performs the family doctor function, responsable for delivering cards, reading activities and providing diagnosis to players when game is over.The scoring system is based on 3 criteria for Metabolic Syndrome diagnosis: glycemia, abdominal obesity and HDL cholesterol. At the end of game, it is possible to calculate the rates of each player and provide proportional diagnosis. The winner is the healthiest that first arrives at HUAP. RESULTS AND DISCUSSION: The game was applied to 50 students and only 10% classified the subject-matter as difficult. This finding highlight the need to establish new methods to enhance the teaching and learning process and decrease the students’ dificulties. Students evaluated the game as an important educational support and 85% of them agreed it complements  and consolidate the content discussed in classroom. Finally, the game was very highly rated by students according to their perception about their own performance while playing.  In addition, 95 % students pointed they would play again and 98% said they think games are able to optimize learning. CONCLUSIONS: It was possible not only to approximate biochemical phenomena to the students’ daily life, but also to solidify the theoretical concepts in a dynamic and fun

  3. SIRT1 and energy metabolism.

    Science.gov (United States)

    Li, Xiaoling

    2013-01-01

    Sirtuin 1 (SIRT1) is the most conserved mammalian NAD(+)-dependent protein deacetylase that has emerged as a key metabolic sensor in various metabolic tissues. In response to different environmental stimuli, SIRT1 directly links the cellular metabolic status to the chromatin structure and the regulation of gene expression, thereby modulating a variety of cellular processes such as energy metabolism and stress response. Recent studies have shown that SIRT1 controls both glucose and lipid metabolism in the liver, promotes fat mobilization and stimulates brown remodeling of the white fat in white adipose tissue, controls insulin secretion in the pancreas, senses nutrient availability in the hypothalamus, influences obesity-induced inflammation in macrophages, and modulates the activity of circadian clock in metabolic tissues. This review focuses on the role of SIRT1 in regulating energy metabolism at different metabolic tissues.

  4. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    ... metabolism and its impact on patient welfare. After underlining the relationship between efficacy, toxicity and drug concentration, the book then considers how metabolizing systems operate and how they impact upon drug concentration...

  5. Can you boost your metabolism?

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000893.htm Can you boost your metabolism? To use the sharing ... boosting metabolism than tactics that work. Some myths can backfire. If you think you are burning more ...

  6. Sleep and Metabolism: An Overview

    OpenAIRE

    Sunil Sharma; Mani Kavuru

    2010-01-01

    Sleep and its disorders are increasingly becoming important in our sleep deprived society. Sleep is intricately connected to various hormonal and metabolic processes in the body and is important in maintaining metabolic homeostasis. Research shows that sleep deprivation and sleep disorders may have profound metabolic and cardiovascular implications. Sleep deprivation, sleep disordered breathing, and circadian misalignment are believed to cause metabolic dysregulation through myriad pathways i...

  7. Metabolic Syndrome, Androgens, and Hypertension

    OpenAIRE

    Moulana, Mohadetheh; Lima, Roberta; Reckelhoff, Jane F.

    2011-01-01

    Obesity is one of the constellation of factors that make up the definition of the metabolic syndrome. Metabolic syndrome is also associated with insulin resistance, dyslipidemia, hypertriglyceridemia, and type 2 diabetes mellitus. The presence of obesity and metabolic syndrome in men and women is also associated with increased risk of cardiovascular disease and hypertension. In men, obesity and metabolic syndrome are associated with reductions in testosterone levels. In women, obesity and met...

  8. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    ..., both under drug pressure and during inhibition. Factors affecting drug metabolism, such as genetic polymorphisms, age and diet are discussed and how metabolism can lead to toxicity is explained. The book concludes with the role of drug metabolism in the commercial development of therapeutic agents as well as the pharmacology of some illicit drugs.

  9. Uncovering transcriptional regulation of metabolism by using metabolic network topology

    DEFF Research Database (Denmark)

    Patil, Kiran Raosaheb; Nielsen, Jens

    2005-01-01

    therefore developed an algorithm that is based on hypothesis-driven data analysis to uncover the transcriptional regulatory architecture of metabolic networks. By using information on the metabolic network topology from genome-scale metabolic reconstruction, we show that it is possible to reveal patterns...... or environmental perturbations. We find that cells respond to perturbations by changing the expression pattern of several genes involved in the specific part(s) of the metabolism in which a perturbation is introduced. These changes then are propagated through the metabolic network because of the highly connected......Cellular response to genetic and environmental perturbations is often reflected and/or mediated through changes in the metabolism, because the latter plays a key role in providing Gibbs free energy and precursors for biosynthesis. Such metabolic changes are often exerted through transcriptional...

  10. Assessing Cardiac Metabolism

    Science.gov (United States)

    Taegtmeyer, Heinrich; Young, Martin E.; Lopaschuk, Gary D.; Abel, E. Dale; Brunengraber, Henri; Darley-Usmar, Victor; Des Rosiers, Christine; Gerszten, Robert; Glatz, Jan F.; Griffin, Julian L.; Gropler, Robert J.; Holzhuetter, Hermann-Georg; Kizer, Jorge R.; Lewandowski, E. Douglas; Malloy, Craig R.; Neubauer, Stefan; Peterson, Linda R.; Portman, Michael A.; Recchia, Fabio A.; Van Eyk, Jennifer E.; Wang, Thomas J.

    2016-01-01

    In a complex system of interrelated reactions, the heart converts chemical energy to mechanical energy. Energy transfer is achieved through coordinated activation of enzymes, ion channels, and contractile elements, as well as structural and membrane proteins. The heart’s needs for energy are difficult to overestimate. At a time when the cardiovascular research community is discovering a plethora of new molecular methods to assess cardiac metabolism, the methods remain scattered in the literature. The present statement on “Assessing Cardiac Metabolism” seeks to provide a collective and curated resource on methods and models used to investigate established and emerging aspects of cardiac metabolism. Some of those methods are refinements of classic biochemical tools, whereas most others are recent additions from the powerful tools of molecular biology. The aim of this statement is to be useful to many and to do justice to a dynamic field of great complexity. PMID:27012580

  11. [Microbiota and metabolic syndrome].

    Science.gov (United States)

    Altuntaş, Yüksel; Batman, Adnan

    2017-04-01

    The role of gut bacteria in the pathogenesis and treatment of various diseases has been a focus of attention in the last 10 years. Prevalence of diabetes, obesity, and cardiovascular diseases continues to increase, in spite of technological developments and treatment alternatives. Microbial dysbiosis, described as the decrease of useful bacteria and the increase of harmful bacteria, has been associated with diabetes, obesity, atherosclerosis, and metabolic syndrome. In microbial dysbiosis, increase of harmful metabolites and changes to composition of bile acids occur via carbohydrate and protein fermentation. As a result, insulin resistance pathways are activated, which initiate the processes of obesity, diabetes, and atherosclerosis. Healthy diet recommendations, including prebiotic and probiotic foods and the use of probiotic agents, look promising for future treatment of metabolic syndrome and cardiovascular diseases.

  12. [Sleep and metabolic disorders].

    Science.gov (United States)

    Micić, Dragan D; Šumarac-Dumanović, Mirjana; Šušić, Veselinka; Pejković, Danica; Polovina, Snežana

    2011-01-01

    In the 20th century, the prevalence of obesity has been increasing worldwide at an alarming rate and it is followed by an increase in the diseases for which obesity is major risk factor, like metabolic syndrome, diabetes type 2 and hypertension. These facts has been resulting in explosion of investigation devoted to explanation of pathogenetic mechanisms of this serious social and medical problems with the main idea to find adequate way of prevention as well as of treatment. Together with the observed epidemy of obesity and Type 2 diabetes, it was found parallel tendency for sleep curtailment, that was confirmed in numerous epidemiological studies, that coincide with its beginning and progress with this two epidemies. This facts lead to investigations with the idea to try to explaine possible mechanisms of the association between sleep curtailment, obesity, type 2 diabetes, metabolic syndrome and polycistic ovary syndrome. Having in mind that insulin resistance is one of the fundamental pathogenetic mechanism in these disorders, numerous studies were done with the aim to explain association between sleep curtailment and insulin resistance in obesity, Type 2 diabetes, metabolic syndrome and polycistic ovary syndrome. It was demonstrated that sleep curtailment may affect energy homeostasis of human organism with the effects on body weight increase through three different ways: appetite increase, prolongation of time for food intake and through decrease of energy expenditure. There are several postulated mechanism for the effect of sleep curtailment on development of insulin resistance as well as for predisposition for Type 2 diabetes. Among possible mechanism are included: increase of sympathetic neuronal acitvity, decreased cerebral utilisation of glucose, increase in evening cortisol values, growth hormone increase and disorder of neuroendocrine control of appetite which increases the risk for getting the body weight. Metabolic systems are of particular interest in

  13. Metabolic syndrome and anesthesia

    OpenAIRE

    Gómez-Alegría Claudio Jaime; Gómez-Camargo Doris; Palomino-Romero Roberto; Pomares-Estrada José

    2010-01-01

    Metabolic Syndrome (MS) represents a constellation of risk factors associated with an increased incidence of cardiovascular disease and progression to diabetes mellitus. Insulin resistance, a state of reduced biological response to physiological insulin concentrations, is a key component of this syndrome appears to result from a primary defect in skeletal muscle glucose transporter. The acute disease and the perioperative period are characterized by a state of insulin resistance that manifest...

  14. Scaling metabolic rate fluctuations

    OpenAIRE

    Labra, Fabio A.; Marquet, Pablo A.; Bozinovic, Francisco

    2007-01-01

    Complex ecological and economic systems show fluctuations in macroscopic quantities such as exchange rates, size of companies or populations that follow non-Gaussian tent-shaped probability distributions of growth rates with power-law decay, which suggests that fluctuations in complex systems may be governed by universal mechanisms, independent of particular details and idiosyncrasies. We propose here that metabolic rate within individual organisms may be considered as an example of an emerge...

  15. Paracetamol metabolism in man

    OpenAIRE

    Adriaenssens, P.I.

    1980-01-01

    The absorption, metabolism and elimination of paracetamol was investigated in healthy subjects after therapeutic doses and also in patients with paracetamol overdosage, some of whom developed liver damage. Paracetamol disposition was also studied in relation to treatment with N-acetylcysteine (NAG),cysteamine and methionine, which were used to prevent paracetamol hepatotoxicity. Sensitive, specific and reproducible analytical methods were developed for the estimation of para...

  16. Metabolic neuropathies and myopathies.

    Science.gov (United States)

    D'Amico, Adele; Bertini, Enrico

    2013-01-01

    Inborn errors of metabolism may impact on muscle and peripheral nerve. Abnormalities involve mitochondria and other subcellular organelles such as peroxisomes and lysosomes related to the turnover and recycling of cellular compartments. Treatable causes are β-oxidation defects producing progressive neuropathy; pyruvate dehydrogenase deficiency, porphyria, or vitamin B12 deficiency causing recurrent episodes of neuropathy or acute motor deficit mimicking Guillain-Barré syndrome. On the other hand, lysosomal (mucopolysaccharidosis, Gaucher and Fabry diseases), mitochondriopathic (mitochondrial or nuclear mutations or mDNA depletion), peroxisomal (adrenomyeloneuropathy, Refsum disease, sterol carrier protein-2 deficiency, cerebrotendinous xanthomatosis, α-methylacyl racemase deficiency) diseases are multisystemic disorders involving also the heart, liver, brain, retina, and kidney. Pathophysiology of most metabolic myopathies is related to the impairment of energy production or to abnormal production of reactive oxygen species (ROS). Main symptoms are exercise intolerance with myalgias, cramps and recurrent myoglobinuria or limb weakness associated with elevation of serum creatine kinase. Carnitine palmitoyl transferase deficiency, followed by acid maltase deficiency, and lipin deficiency, are the most common cause of isolated rhabdomyolysis. Metabolic myopathies are frequently associated to extra-neuromuscular disorders particularly involving the heart, liver, brain, retina, skin, and kidney. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Analytics for metabolic engineering

    Directory of Open Access Journals (Sweden)

    Christopher J Petzold

    2015-09-01

    Full Text Available Realizing the promise of metabolic engineering has been slowed by challenges related to moving beyond proof-of-concept examples to robust and economically viable systems. Key to advancing metabolic engineering beyond trial-and-error research is access to parts with well-defined performance metrics that can be readily applied in vastly different contexts with predictable effects. As the field now stands, research depends greatly on analytical tools that assay target molecules, transcripts, proteins, and metabolites across different hosts and pathways. Screening technologies yield specific information for many thousands of strain variants while deep omics analysis provide a systems-level view of the cell factory. Efforts focused on a combination of these analyses yield quantitative information of dynamic processes between parts and the host chassis that drive the next engineering steps. Overall, the data generated from these types of assays aid better decision-making at the design and strain construction stages to speed progress in metabolic engineering research.

  18. Blood Test: Comprehensive Metabolic Panel (CMP)

    Science.gov (United States)

    ... Voice in Health Care Decisions Blood Test: Comprehensive Metabolic Panel (CMP) KidsHealth > For Parents > Blood Test: Comprehensive Metabolic Panel ( ... or kidneys) is working. What Is a Comprehensive Metabolic Panel (CMP)? The comprehensive metabolic panel (CMP) is a ...

  19. Maternal cardiac metabolism in pregnancy

    Science.gov (United States)

    Liu, Laura X.; Arany, Zolt

    2014-01-01

    Pregnancy causes dramatic physiological changes in the expectant mother. The placenta, mostly foetal in origin, invades maternal uterine tissue early in pregnancy and unleashes a barrage of hormones and other factors. This foetal ‘invasion’ profoundly reprogrammes maternal physiology, affecting nearly every organ, including the heart and its metabolism. We briefly review here maternal systemic metabolic changes during pregnancy and cardiac metabolism in general. We then discuss changes in cardiac haemodynamic during pregnancy and review what is known about maternal cardiac metabolism during pregnancy. Lastly, we discuss cardiac diseases during pregnancy, including peripartum cardiomyopathy, and the potential contribution of aberrant cardiac metabolism to disease aetiology. PMID:24448314

  20. Disturbances of lipoprotein metabolism in metabolic syndro

    Directory of Open Access Journals (Sweden)

    Marta Czyżewska

    2010-01-01

    Full Text Available Dyslipidemia in metabolic syndrome (MS, called the atherogenic triad, includes elevated levels of plasma triglycerides (TGs, low levels of HDL-cholesterol (HDL-CH, and the presence of small dense low-density lipoproteins (sdLDLs with normal or slightly elevated LDL-CH levels. Insulin resistance drives the increase in the three main sources of TG for VLDL synthesis: fatty-acid flux from adipose tissue, de novo lipogenesis, and uptake of remnant lipoproteins. Overproduction of VLDL, predominantly triglyceride-rich large VLDL1 particles, induces the cascade of events which lead to abnormalities of other plasma lipoproteins. The accumulation of VLDL in plasma and decreased activity of lipoprotein lipase (LPL impair the catabolism of chylomicrons. Moreover, hyperinsulinemia induces increased intestinal production of chylomicrons. These factors cause augmented postprandial lipemia. Hepatic overproduction of VLDL leads to an increased level of VLDL remnants in plasma. Highly atherogenic sdLDLs are generated from VLDL1 particles by the action of LPL, cholesterol ester transfer protein (CETP, and hepatic lipase (HL. In the presence of hypertriglyceridemia, accelerated CETP-mediated lipid transfer generates TG-enriched HDL particles. This enhances HDL catabolism mediated by HL and endothelial lipase (EL. The assessment of risk of atherosclerotic cardiovascular disease in MS related to low HDL-CH and the presence of sdLDL particles may be improved by the incorporation of measurements of apolipoproteins (apo-B and apoA-I into clinical practice. In addition, the concentration of non-HDL-CH may be useful in quantifying apo-B-containing atherogenic lipoproteins.

  1. Tumor Metabolism of Malignant Gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Ru, Peng; Williams, Terence M.; Chakravarti, Arnab; Guo, Deliang, E-mail: deliang.guo@osumc.edu [Department of Radiation Oncology, Ohio State University Comprehensive Cancer Center & Arthur G James Cancer Hospital, Columbus, OH 43012 (United States)

    2013-11-08

    Constitutively activated oncogenic signaling via genetic mutations such as in the EGFR/PI3K/Akt and Ras/RAF/MEK pathways has been recognized as a major driver for tumorigenesis in most cancers. Recent insights into tumor metabolism have further revealed that oncogenic signaling pathways directly promote metabolic reprogramming to upregulate biosynthesis of lipids, carbohydrates, protein, DNA and RNA, leading to enhanced growth of human tumors. Therefore, targeting cell metabolism has become a novel direction for drug development in oncology. In malignant gliomas, metabolism pathways of glucose, glutamine and lipid are significantly reprogrammed. Moreover, molecular mechanisms causing these metabolic changes are just starting to be unraveled. In this review, we will summarize recent studies revealing critical gene alterations that lead to metabolic changes in malignant gliomas, and also discuss promising therapeutic strategies via targeting the key players in metabolic regulation.

  2. Bioleaching of dewatered metal plating sludge by Acidithiobacillus ...

    African Journals Online (AJOL)

    The objective of the present study was to evaluate the application of bioleaching technique to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge not containing sulphide or sulphate compounds. The effects of pH, pulp density of the sludge and agitation time were investigated in both shake ...

  3. Metabolic mechanisms in heart failure.

    Science.gov (United States)

    Ashrafian, Houman; Frenneaux, Michael P; Opie, Lionel H

    2007-07-24

    Although neurohumoral antagonism has successfully reduced heart failure morbidity and mortality, the residual disability and death rate remains unacceptably high. Though abnormalities of myocardial metabolism are associated with heart failure, recent data suggest that heart failure may itself promote metabolic changes such as insulin resistance, in part through neurohumoral activation. A detrimental self-perpetuating cycle (heart failure --> altered metabolism --> heart failure) that promotes the progression of heart failure may thus be postulated. Accordingly, we review the cellular mechanisms and pathophysiology of altered metabolism and insulin resistance in heart failure. It is hypothesized that the ensuing detrimental myocardial energetic perturbations result from neurohumoral activation, increased adverse free fatty acid metabolism, decreased protective glucose metabolism, and in some cases insulin resistance. The result is depletion of myocardial ATP, phosphocreatine, and creatine kinase with decreased efficiency of mechanical work. On the basis of the mechanisms outlined, appropriate therapies to mitigate aberrant metabolism include intense neurohumoral antagonism, limitation of diuretics, correction of hypokalemia, exercise, and diet. We also discuss more novel mechanistic-based therapies to ameliorate metabolism and insulin resistance in heart failure. For example, metabolic modulators may optimize myocardial substrate utilization to improve cardiac function and exercise performance beyond standard care. The ultimate success of metabolic-based therapy will be manifest by its capacity further to lessen the residual mortality in heart failure.

  4. Extranuclear Sirtuins and Metabolic Stress.

    Science.gov (United States)

    Elkhwanky, Mahmoud-Sobhy; Hakkola, Jukka

    2018-03-10

    Extranuclear sirtuins in cytosol (SIRT2) and mitochondria (SIRT3, SIRT4, and SIRT5) are key regulators of metabolic enzymes and the antioxidative defense mechanisms. They play an important role in the adjustment of metabolic pathways in alterations of the nutritional status. Recent Advances: Recent studies have shown that in addition to lysine deacetylation, sirtuins catalyze several different lysine deacylation reactions, removal of lipid modifications, and adenosine diphosphate-ribosylation. Large-scale studies have revealed hundreds of target proteins regulated by different sirtuin modifications. Sensing of the metabolic state and regulation of the sirtuin function and expression are critical components of the machinery, optimizing cellular functions in the switch from fed to fasting condition. Overfeeding, obesity, and metabolic diseases cause metabolic stress that dysregulates the sirtuins, which may play a role in the pathogenesis and complications of metabolic diseases such as type 2 diabetes, fatty liver disease, and cardiac diseases. In the current review, we will discuss the significance of the extranuclear sirtuins as metabolic regulators and in protection against the reactive oxygen species, and also how these sirtuins are regulated by metabolic status and their putative role in metabolic diseases. To efficiently utilize sirtuins as drug targets for treatment of the metabolic diseases, better understanding of the sirtuin functions, targets, regulation, and cross talk is needed. Furthermore, more studies in humans are needed to confirm the many observations mainly made in animal and cell models so far. Antioxid. Redox Signal. 28, 662-676.

  5. Polyamine metabolism revisited.

    Science.gov (United States)

    Urdiales, J L; Medina MA; Sánchez-Jiménez, F

    2001-09-01

    The natural polyamines putrescine, spermidine and spermine play an essential role in cell growth and differentiation. Cellular polyamine depletion results in inhibition of growth, whereas its accumulation appears to be toxic. Intracellular levels of polyamines are regulated by a multitude of mechanisms affecting their synthesis, degradation, uptake and excretion. The three key enzymes in the regulation of polyamine metabolism have short half-lives and are inducible. Ornithine and S-adenosylmethionine decarboxylases regulate polyamine biosynthesis whereas spermidine/spermine acetyltransferase regulates polyamine interconvertion and degradation.

  6. Inositol Metabolism in Plants

    Science.gov (United States)

    Kroh, M.; Miki-Hirosige, H.; Rosen, W.; Loewus, F.

    1970-01-01

    When detached flowers or isolated pistils of Lilium longiflorum are given myoinositol-U-14C or -2-3H as dilute solution through the severed pedicel, label is quickly distributed by the vascular system. In the case of pistils, a pattern of labeling in ovary, style, and stigma is obtained which indicates that products of myoinositol metabolism are utilized in the biosynthesis of exudate (secretion product) of the stigma and style as well as for components of pistil cell walls. Pollination had no discernible effect on labeling pattern. Images PMID:5436329

  7. [Obesity and bone metabolism].

    Science.gov (United States)

    Holecki, Michał; Zahorska-Markiewicz, Barbara; Wiecek, Andrzej; Nieszporek, Teresa; Zak-Gołab, Agnieszka

    2008-01-01

    Both bone and adipose tissue change their size, shape and distribution during the whole human being's life. Many factors, including genetic factors, hormones and activity of nervous system are responsible for these changes. It is generally accepted that obesity has a protective effect on bone tissue. On the other hand some authors present an opposite results--the lack of beneficial effect of obesity on development of osteoporosis fractures. The aim of this article was to present and discuss the relations between adipose tissue and bone metabolism.

  8. Crassulacean acid metabolism

    Directory of Open Access Journals (Sweden)

    Thomas David Geydan

    2005-07-01

    Full Text Available A review of Crassulacean acid metabolism is presented, characterized by showing the occurrence, activity and plasticity of these complex mechanism at the physiological, biochemical and molecular level, framed by the presence of the denominated four phases in CAM and its repercussion and expression due to different stresses in an ecological context. The basic enzymes, and metabolites necessary for the optional functioning of CAM are presented as well as their mode of action and cellular control. Finally, it is shown how environmental conditions and molecular signalling mediate the phenotypic plasticity.

  9. Metabolic Reprogramming in Brain Tumors.

    Science.gov (United States)

    Venneti, Sriram; Thompson, Craig B

    2017-01-24

    Next-generation sequencing has substantially enhanced our understanding of the genetics of primary brain tumors by uncovering several novel driver genetic alterations. How many of these genetic modifications contribute to the pathogenesis of brain tumors is not well understood. An exciting paradigm emerging in cancer biology is that oncogenes actively reprogram cellular metabolism to enable tumors to survive and proliferate. We discuss how some of these genetic alterations in brain tumors rewire metabolism. Furthermore, metabolic alterations directly impact epigenetics well beyond classical mechanisms of tumor pathogenesis. Metabolic reprogramming in brain tumors is also influenced by the tumor microenvironment contributing to drug resistance and tumor recurrence. Altered cancer metabolism can be leveraged to noninvasively image brain tumors, which facilitates improved diagnosis and the evaluation of treatment effectiveness. Many of these aspects of altered metabolism provide novel therapeutic opportunities to effectively treat primary brain tumors.

  10. Metabolic syndrome, diet and exercise.

    Science.gov (United States)

    De Sousa, Sunita M C; Norman, Robert J

    2016-11-01

    Polycystic ovary syndrome (PCOS) is associated with a range of metabolic complications including insulin resistance (IR), obesity, dyslipidaemia, hypertension, obstructive sleep apnoea (OSA) and non-alcoholic fatty liver disease. These compound risks result in a high prevalence of metabolic syndrome and possibly increased cardiovascular (CV) disease. As the cardiometabolic risk of PCOS is shared amongst the different diagnostic systems, all women with PCOS should undergo metabolic surveillance though the precise approach differs between guidelines. Lifestyle interventions consisting of increased physical activity and caloric restriction have been shown to improve both metabolic and reproductive outcomes. Pharmacotherapy and bariatric surgery may be considered in resistant metabolic disease. Issues requiring further research include the natural history of PCOS-associated metabolic disease, absolute CV risk and comparative efficacy of lifestyle interventions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Biochemical Hypermedia: Galactose Metabolism.

    Directory of Open Access Journals (Sweden)

    J.K. Sugai

    2013-05-01

    Full Text Available Introduction: Animations of biochemical processes and virtual laboratory environments lead to true molecular simulations. The use of interactive software’s in education can improve cognitive capacity, better learning and, mainly, it makes information acquisition easier. Material and Methods: This work presents the development of a biochemical hypermedia to understanding of the galactose metabolism. It was developed with the help of concept maps, ISIS Draw, ADOBE Photoshop and FLASH MX Program. Results and Discussion: A step by step animation process shows the enzymatic reactions of galactose conversion to glucose-1-phosphate (to glycogen synthesis, glucose-6-phosphate (glycolysis intermediary, UDP-galactose (substrate to mucopolysaccharides synthesis and collagen’s glycosylation. There are navigation guide that allow scrolling the mouse over the names of the components of enzymatic reactions of via the metabolism of galactose. Thus, explanatory text box, chemical structures and animation of the actions of enzymes appear to navigator. Upon completion of the module, the user’s response to the proposed exercise can be checked immediately through text box with interactive content of the answer. Conclusion: This hypermedia was presented for undergraduate students (UFSC who revealed that it was extremely effective in promoting the understanding of the theme.

  12. Metabolic Syndrome: Hyperlipidemia.

    Science.gov (United States)

    Bragg, Dee Ann Stults; Walling, Anne

    2015-08-01

    Metabolic syndrome is associated with an elevated risk of cardiovascular disease and premature mortality. When metabolic syndrome includes lipid abnormalities, management goals are weight loss and cardiovascular risk management through lifestyle modifications (eg, diet, exercise), and, when appropriate, lowering of lipid levels with pharmacotherapy. Healthy diets are recommended, particularly the Mediterranean diet. Patients also should set a goal of at least 30 minutes of moderate to vigorous exercise on most, preferably all, days of the week. Guidelines provide criteria for statin treatment based on overall cardiovascular risk. High-intensity statin treatment (eg, rosuvastatin 20 to 40 mg, atorvastatin 40 to 80 mg) typically is recommended unless the patient cannot tolerate therapy. Approximately 5% of patients experience statin-induced myalgia, in which case moderate-intensity treatment can be tried. Lipid levels should be reevaluated 4 to 12 weeks after initiating therapy; lipid levels can be measured without fasting. A lack of improvement often indicates nonadherence. Bile acid sequestrants, fibric acids, and niacin can be used if other drugs are not tolerated. The evidence to support use of integrative medicine is limited, but the strongest evidence of benefit is for garlic (Allium sativum). Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

  13. [Sleep duration and metabolism].

    Science.gov (United States)

    Viot-Blanc, V

    2015-12-01

    Sleep duration has gradually diminished during the last decade while obesity and type 2 diabetes have become epidemics. Experimental sleep curtailment leads to increased appetite, hormonal disturbances and, especially, insulin resistance. Numerous epidemiological studies have therefore examined whether habitual short sleep is associated with obesity and type 2 diabetes. A large majority of cross-sectional studies have confirmed an association between short, and also long sleep duration and obesity in adults more than in the elderly. Short sleep is strongly associated to obesity in children and adolescents. Prospective studies, including studies in children, are not conclusive with regard to the effect of short sleep on the incidence of obesity. Both short and long sleep durations are associated with diabetes, but only short sleep duration seems predictive of future diabetes. Insomnia seems to be a strong contributor to short sleep duration but the association of insomnia with obesity is not clear. Insomnia is associated with type 2 diabetes and also predictive of a higher incidence. Other studies have shown that short sleep duration and insomnia are associated with, and sometime predictive of, other components of the metabolic syndrome, especially hypertension and the risk of coronary disease. The treatment of short sleep duration and insomnia with regard to their effects on the metabolic syndrome merits further study. Copyright © 2015 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  14. Metabolic topography of Parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Seung [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Parkinson's disease is one of the most frequent neurodegenerative diseases, which mainly affects the elderly. Parkinson's disease is often difficult to differentiate from atypical parkinson disorder such as progressive supranuclear palsy, multiple system atrophy, dementia with Lewy body, and corticobasal ganglionic degeneration, based on the clinical findings because of the similarity of phenotypes and lack of diagnostic markers. The accurate diagnosis of Parkinson's disease and atypical Parkinson disorders is not only important for deciding on treatment regimens and providing prognosis, but also it is critical for studies designed to investigate etiology and pathogenesis of parkinsonism and to develop new therapeutic strategies. Although degeneration of the nigrostriatal dopamine system results in marked loss of striatal dopamine content in most of the diseases causing parkinsonism, pathologic studies revealed different topographies of the neuronal cell loss in Parkinsonism. Since the regional cerebral glucose metabolism is a marker of integrated local synaptic activity and as such is sensitive to both direct neuronal/synaptic damage and secondary functional disruption at synapses distant from the primary site of pathology, and assessment of the regional cerebral glucose metabolism with F-18 FDG PET is useful in the differential diagnosis of parkinsonism and evaluating the pathophysiology of Parkinsonism.

  15. Metabolic flexibility and insulin resistance

    OpenAIRE

    Galgani, Jose E.; Moro, Cedric; Ravussin, Eric

    2008-01-01

    Metabolic flexibility is the capacity for the organism to adapt fuel oxidation to fuel availability. The inability to modify fuel oxidation in response to changes in nutrient availability has been implicated in the accumulation of intramyocellular lipid and insulin resistance. The metabolic flexibility assessed by the ability to switch from fat to carbohydrate oxidation is usually impaired during a hyperinsulinemic clamp in insulin-resistant subjects; however, this “metabolic inflexibility” i...

  16. Artificial Promoters for Metabolic Optimization

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1998-01-01

    In this article, we review some of the expression systems that are available for Metabolic Control Analysis and Metabolic Engineering, and examine their advantages and disadvantages in different contexts. In a recent approach, artificial promoters for modulating gene expression in micro-organisms......In this article, we review some of the expression systems that are available for Metabolic Control Analysis and Metabolic Engineering, and examine their advantages and disadvantages in different contexts. In a recent approach, artificial promoters for modulating gene expression in micro...

  17. Clinical update on metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Juan Diego Hernández-Camacho

    2017-12-01

    Full Text Available Metabolic syndrome has been defined as a global issue since it affects a lot of people. Numerous factors are involved in metabolic syndrome development. It has been described that metabolic syndrome has negative consequences on health. Consequently, a lot of treatments have been proposed to palliate it such as drugs, surgery or life style changes where nutritional habits have shown to be an important point in its management. The current study reviews the literature existing about the actual epidemiology of metabolic syndrome, the components involucrate in its appearance and progression, the clinical consequences of metabolic syndrome and the nutritional strategies reported in its remission. A bibliographic search in PubMed and Medline was performed to identify eligible studies. Authors obtained that metabolic syndrome is present in population from developed and undeveloped areas in a huge scale. Environmental and genetic elements are involucrate in metabolic syndrome development. Metabolic syndrome exponentially increased risk of cardiovascular disease, some types of cancers, diabetes mellitus type 2, sleep disturbances, etc. Nutritional treatments play a crucial role in metabolic syndrome prevention, treatment and recovery.

  18. Drug-Induced Metabolic Acidosis

    Science.gov (United States)

    Pham, Amy Quynh Trang; Xu, Li Hao Richie; Moe, Orson W.

    2015-01-01

    Metabolic acidosis could emerge from diseases disrupting acid-base equilibrium or from drugs that induce similar derangements. Occurrences are usually accompanied by comorbid conditions of drug-induced metabolic acidosis, and clinical outcomes may range from mild to fatal. It is imperative that clinicians not only are fully aware of the list of drugs that may lead to metabolic acidosis but also understand the underlying pathogenic mechanisms. In this review, we categorized drug-induced metabolic acidosis in terms of pathophysiological mechanisms, as well as individual drugs’ characteristics. PMID:26918138

  19. Gut Microbiota and Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    Kyu Yeon Hur

    2015-06-01

    Full Text Available Gut microbiota plays critical physiological roles in the energy extraction and in the control of local or systemic immunity. Gut microbiota and its disturbance also appear to be involved in the pathogenesis of diverse diseases including metabolic disorders, gastrointestinal diseases, cancer, etc. In the metabolic point of view, gut microbiota can modulate lipid accumulation, lipopolysaccharide content and the production of short-chain fatty acids that affect food intake, inflammatory tone, or insulin signaling. Several strategies have been developed to change gut microbiota such as prebiotics, probiotics, certain antidiabetic drugs or fecal microbiota transplantation, which have diverse effects on body metabolism and on the development of metabolic disorders.

  20. Genetic-Metabolic Coupling for Targeted Metabolic Engineering

    DEFF Research Database (Denmark)

    Cardinale, Stefano; Tueros Farfan, Felipe Gonzalo; Sommer, Morten Otto Alexander

    2017-01-01

    Production of chemicals in microbes often employs potent biosynthetic enzymes, which can interact with the microbial native metabolism to affect cell fitness and product yield. However, production optimization largely relies on data collected from wild-type strains in the absence of metabolic...

  1. Metabolic flux analysis: recent advances in carbon metabolism in plants.

    Science.gov (United States)

    Dieuaide-Noubhani, Martine; Alonso, Ana-Paula; Rolin, Dominique; Eisenreich, Wolfgang; Raymond, Philippe

    2007-01-01

    Isotopic tracers are used to both trace metabolic pathways and quantify fluxes through these pathways. The use of different labeling methods recently led to profound changes in our views of plant metabolism. Examples are taken from primary metabolism, with sugar interconversions, carbon partitioning between glycolysis and the pentose phosphate pathway, or metabolite inputs into the tricarboxylic acid (TCA) cycle, as well as from secondary metabolism with the relative contribution of the plastidial and cytosolic pathways to the biosynthesis of terpenoids. While labeling methods are often distinguished according to the instruments used for label detection, emphasis is put here on labeling duration. Short time labeling is adequate to study limited areas of the metabolic network. Long-term labeling, when designed to obtain metabolic and isotopic steady-state, allows to calculate various fluxes in large areas ofcentral metabolism. After longer labeling periods, large amounts of label accumulate in structural or storage compounds: their detailed study through the retrobiosynthetic method gives access to the biosynthetic pathways of otherwise undetectable precursors. This chapter presents the power and limits of the different methods, and illustrates how they can be associated with each other and with other methods of cell biology, to provide the information needed for a rational approach of metabolic engineering.

  2. Reconciling theories for metabolic scaling.

    Science.gov (United States)

    Maino, James L; Kearney, Michael R; Nisbet, Roger M; Kooijman, Sebastiaan A L M

    2014-01-01

    Metabolic theory specifies constraints on the metabolic organisation of individual organisms. These constraints have important implications for biological processes ranging from the scale of molecules all the way to the level of populations, communities and ecosystems, with their application to the latter emerging as the field of metabolic ecology. While ecologists continue to use individual metabolism to identify constraints in ecological processes, the topic of metabolic scaling remains controversial. Much of the current interest and controversy in metabolic theory relates to recent ideas about the role of supply networks in constraining energy supply to cells. We show that an alternative explanation for physicochemical constraints on individual metabolism, as formalised by dynamic energy budget (DEB) theory, can contribute to the theoretical underpinning of metabolic ecology, while increasing coherence between intra- and interspecific scaling relationships. In particular, we emphasise how the DEB theory considers constraints on the storage and use of assimilated nutrients and derive an equation for the scaling of metabolic rate for adult heterotrophs without relying on optimisation arguments or implying cellular nutrient supply limitation. Using realistic data on growth and reproduction from the literature, we parameterise the curve for respiration and compare the a priori prediction against a mammalian data set for respiration. Because the DEB theory mechanism for metabolic scaling is based on the universal process of acquiring and using pools of stored metabolites (a basal feature of life), it applies to all organisms irrespective of the nature of metabolic transport to cells. Although the DEB mechanism does not necessarily contradict insight from transport-based models, the mechanism offers an explanation for differences between the intra- and interspecific scaling of biological rates with mass, suggesting novel tests of the respective hypotheses. © 2013 The

  3. Structural Control of Metabolic Flux

    Science.gov (United States)

    Sajitz-Hermstein, Max; Nikoloski, Zoran

    2013-01-01

    Organisms have to continuously adapt to changing environmental conditions or undergo developmental transitions. To meet the accompanying change in metabolic demands, the molecular mechanisms of adaptation involve concerted interactions which ultimately induce a modification of the metabolic state, which is characterized by reaction fluxes and metabolite concentrations. These state transitions are the effect of simultaneously manipulating fluxes through several reactions. While metabolic control analysis has provided a powerful framework for elucidating the principles governing this orchestrated action to understand metabolic control, its applications are restricted by the limited availability of kinetic information. Here, we introduce structural metabolic control as a framework to examine individual reactions' potential to control metabolic functions, such as biomass production, based on structural modeling. The capability to carry out a metabolic function is determined using flux balance analysis (FBA). We examine structural metabolic control on the example of the central carbon metabolism of Escherichia coli by the recently introduced framework of functional centrality (FC). This framework is based on the Shapley value from cooperative game theory and FBA, and we demonstrate its superior ability to assign “share of control” to individual reactions with respect to metabolic functions and environmental conditions. A comparative analysis of various scenarios illustrates the usefulness of FC and its relations to other structural approaches pertaining to metabolic control. We propose a Monte Carlo algorithm to estimate FCs for large networks, based on the enumeration of elementary flux modes. We further give detailed biological interpretation of FCs for production of lactate and ATP under various respiratory conditions. PMID:24367246

  4. The metabolic syndrome.

    Science.gov (United States)

    Harris, Mark F

    2013-08-01

    The metabolic syndrome (MetSy) is increasingly common in Australia. It is associated with the rise in obesity and lifestyle risk behaviours. It is also controversial - its value in predicting cardiovascular disease and diabetes risk and in guiding therapy has been challenged. This article aims to provide advice on the diagnosis of the MetSy and the principles for its prevention and management in the context of primary care, taking into consideration aetiological factors and the complexity of managing its constituent risk factors. Diagnosis of the MetSy is useful in focusing attention on central adiposity and insulin resistance as risk factors both for the syndrome, and cardiovascular and diabetes morbidity and mortality. Its assessment requires measurement of waist circumference - a simple but seldom performed procedure in general practice. The most essential components for the prevention and management of the MetSy are measures to change diet and physical activity in order to achieve and sustain weight loss.

  5. A Metabolic Race

    Directory of Open Access Journals (Sweden)

    Amanda Mendonça da Silva Costa

    2017-10-01

    Full Text Available It is common among medical students and other courses in biomedical area, to raise questions about the applicability of certain biochemical concepts. Since such contents will be present throughout their professional lifes, it is essential to emphasize the relevance of the basic cycle, stage of the medical training in which biochemistry teaching is inserted. With the aim of bring together theory and future clinical practice, a board game was developed based on a biochemical approach of Metabolic Syndrome (MS clinical cases. The game reproduces the environment and routine experienced by students of Federal Fluminense University, in which players are divided into “patients and doctors” and move on a simplified map of Niterói city. Questions and challenge cards are used to test students' biochemical knowledge and a scoring system based on three of the five criteria to diagnose MS, is used to provide proportional diagnoses to the each player’s performance.

  6. Regulation of Terpene Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Rodney Croteau

    2004-03-14

    OAK-B135 Research over the last four years has progressed fairly closely along the lines initially proposed, with progress-driven expansion of Objectives 1, 2 and 3. Recent advances have developed from three research thrusts: 1. Random sequencing of an enriched peppermint oil gland cDNA library has given access to a large number of potential pathway and regulatory genes for test of function; 2. The availability of new DNA probes and antibodies has permitted investigation of developmental regulation and organization of terpenoid metabolism; and 3. The development of a transformation system for peppermint by colleagues at Purdue University has allowed direct transgenic testing of gene function and added a biotechnological component to the project. The current status of each of the original research objectives is outlined below.

  7. [Regulation of terpene metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.

    1989-11-09

    Terpenoid oils, resins, and waxes from plants are important renewable resources. The objective of this project is to understand the regulation of terpenoid metabolism using the monoterpenes (C[sub 10]) as a model. The pathways of monoterpene biosynthesis and catabolism have been established, and the relevant enzymes characterized. Developmental studies relating enzyme levels to terpene accumulation within the oil gland sites of synthesis, and work with bioregulators, indicate that monoterpene production is controlled by terpene cyclases, the enzymes catalyzing the first step of the monoterpene pathway. As the leaf oil glands mature, cyclase levels decline and monoterpene biosynthesis ceases. Yield then decreases as the monoterpenes undergo catabolism by a process involving conversion to a glycoside and transport from the leaf glands to the root. At this site, the terpenoid is oxidatively degraded to acetate that is recycled into other lipid metabolites. During the transition from terpene biosynthesis to catabolism, the oil glands undergo dramatic ultrastructural modification. Degradation of the producing cells results in mixing of previously compartmentized monoterpenes with the catabolic enzymes, ultimately leading to yield decline. This regulatory model is being applied to the formation of other terpenoid classes (C[sub 15] C[sub 20], C[sub 30], C[sub 40]) within the oil glands. Preliminary investigations on the formation of sesquiterpenes (C[sub 15]) suggest that the corresponding cyclases may play a lesser role in determining yield of these products, but that compartmentation effects are important. From these studies, a comprehensive scheme for the regulation of terpene metabolism is being constructed. Results from this project wail have important consequences for the yield and composition of terpenoid natural products that can be made available for industrial exploitation.

  8. Aldosterone in Metabolic Alkalosis*

    Science.gov (United States)

    Kassirer, Jerome P.; Appleton, Frederick M.; Chazan, Joseph A.; Schwartz, William B.

    1967-01-01

    Studies have been carried out in human volunteer subjects to evaluate the role of aldosterone in the development, maintenance, and correction of metabolic alkalosis induced by selective depletion of hydrochloric acid. During the first phase of our study the rate of aldosterone secretion was measured before the induction of alkalosis (while the subjects were on a low salt diet) and again after a steady state of metabolic alkalosis had been established. The data demonstrate a fall in aldosterone secretion from a value of approximately 500 μg/day to a value of approximately 200 μg/day. Thus, it appears that an increased rate of aldosterone secretion is not a prerequisite to the elevation of the renal bicarbonate threshold. During the second phase of our study, aldosterone was administered to the alkalotic subjects in doses of 1000 μg/day (or deoxycorticosterone acetate in doses of 40 mg/day) in order to determine the effects of a persistent steroid excess on the ability of sodium chloride to correct the acid-base disturbance. The data demonstrate that despite the administration of steroid, the ingestion of sodium chloride led to a reduction in plasma bicarbonate concentration from 39 to 29 mEq/liter, accompanied by a suppression of renal acid excretion. This reduction in plasma bicarbonate concentration occurred without a concomitant retention of potassium, a deficit of as much as 400-500 mEq of potassium persisting during repair of the acid-base disturbance. Our findings suggest that “saline-resistant” alkalosis, when it occurs in the absence of primary hyperadrenalism, cannot be attributed to aldosterone excess and/or potassium depletion of the magnitude seen in our study. We also suggest the need for a reappraisal of the way in which aldosterone excess contributes to the genesis and maintenance of alkalosis in primary aldosteronism. PMID:6061733

  9. Metabolism of endocannabinoids

    Directory of Open Access Journals (Sweden)

    Michał Biernacki

    2016-08-01

    Full Text Available Endocannabinoids belong to a group of ester, ether and amide derivatives of fatty acids, which are endogenous ligands of receptors CB1, CB2, TRPV1 and GPR55 that are included in the endocannabinoid system of the animal organism. The best known endocannabinoids are: N-arachidonylethanolamide called anandamide (AEA and 2-arachidonoylglycerol (2-AG. They occur in all organisms, and their highest level is observed in the brain. In this review the mechanisms of synthesis and degradation of both AEA and 2-AG are shown. Endocannabinoids are synthesized from phospholipids (mainly phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol located in the cell membrane. As a result of arachidonic acid transfer from phosphatidylcholine to phosphatidylethanolamine, N-arachidonoyl phosphatidylethanolamine is formed, which is hydrolyzed to AEA by phospholipase D, C and A2. However, 2-AG is formed during the hydrolysis of phosphatidylinositol catalyzed mainly by DAGL. The primary role of endocannabinoids is the activation of cannabinoid receptors. Both AEA and 2-AG are primarily agonists of the CB1 receptor and to a lower degree CB2 and TRPV1r eceptors, but 2-AG has stronger affinity for these receptors. Through activation of receptors, endocannabinoids affect cellular metabolism and participate in the metabolic processes by receptor-independent pathways. Endocannabinoids which are not bound to the receptors are degraded. The main enzymes responsible for the hydrolysis of AEA and 2-AG are FAAH and MAGL, respectively. Apart from hydrolytic degradation, endocannabinoids may also be oxidized by cyclooxygenase-2, lipoxygenases, and cytochrome P450. It has been shown that the metabolites of both endocannabinoids also have biological significance.

  10. Metabolic Flux Analysis of Mammalian Cells

    NARCIS (Netherlands)

    Martens, D.E.

    2006-01-01

    Metabolic flux analysis has become a standard tool for analyzing metabolism and optimizing bioprocesses. Metabolic flux analysis makes use of a metabolic reaction network in combination with extra-cellular measurements and mass balancing to calculate flux distributions in metabolism. It is a useful

  11. Sex steroids and lipoprotein metabolism

    NARCIS (Netherlands)

    Gevers Leuven, J.A.

    1994-01-01

    Lipoprotein metabolism is involved in atherogenesis. Female sex-hormones have substantial effects on both lipoprotein metabolism and the vessel wall. Cholesterol, one of the major lipids in lipoproteins, is both the substrate for, and the target of, the steroidal sex hormones.

  12. Metabolic syndrome-associated osteoarthritis.

    Science.gov (United States)

    Courties, Alice; Sellam, Jérémie; Berenbaum, Francis

    2017-03-01

    Interest in the metabolic syndrome-associated osteoarthritis phenotype is increasing. Here, we summarize recently published significant findings. Meta-analyses confirmed an association between type 2 diabetes and osteoarthritis and between cardiovascular diseases and osteoarthritis. Recent advances in the study of metabolic syndrome-associated osteoarthritis have focused on a better understanding of the role of metabolic diseases in inducing or aggravating joint damage. In-vivo models of obesity, diabetes, or dyslipidemia have helped to better decipher this association. They give emerging evidence that, beyond the role of common pathogenic mechanisms for metabolic diseases and osteoarthritis (i.e., low-grade inflammation and oxidative stress), metabolic diseases have a direct systemic effect on joints. In addition to the impact of weight, obesity-associated inflammation is associated with osteoarthritis severity and may modulate osteoarthritis progression in mouse models. As well, osteoarthritis synovium from type 2 diabetic patients shows insulin-resistant features, which may participate in joint catabolism. Finally, exciting data are emerging on the association of gut microbiota and circadian rhythm and metabolic syndrome-associated osteoarthritis. The systemic role of metabolic syndrome in osteoarthritis pathophysiology is now better understood, but new avenues of research are being pursued to better decipher the metabolic syndrome-associated osteoarthritis phenotype.

  13. Selected Metabolic Responses to Skateboarding

    Science.gov (United States)

    Hetzler, Ronald K.; Hunt, Ian; Stickley, Christopher D.; Kimura, Iris F.

    2011-01-01

    Despite the popularity of skateboarding worldwide, the authors believe that no previous studies have investigated the metabolic demands associated with recreational participation in the sport. Although metabolic equivalents (METs) for skateboarding were published in textbooks, the source of these values is unclear. Therefore, the rise in…

  14. Metabolic syndrome and acute pancreatitis.

    Science.gov (United States)

    Mikolasevic, I; Milic, S; Orlic, L; Poropat, G; Jakopcic, I; Franjic, N; Klanac, A; Kristo, N; Stimac, D

    2016-07-01

    The aim of our study was to investigate the influence of metabolic syndrome on the course of acute pancreatitis determined by disease severity, the presence of local and systemic complications and survival rate. 609 patients admitted to our hospital in the period from January 1, 2008 up to June 31, 2015 with the diagnosis of acute pancreatitis were analyzed. The diagnosis and the severity of acute pancreatitis were made according to the revised Atlanta classification criteria from 2012. Of 609 patients with acute pancreatitis, 110 fulfilled the criteria for metabolic syndrome. Patients with metabolic syndrome had statistically significantly higher incidence of moderately severe (38.2% vs. 28.5%; p=0.05) and severe (22.7% vs. 12.8%; p=0.01) acute pancreatitis in comparison to those without metabolic syndrome, while patients without metabolic syndrome had higher incidence of mild acute pancreatitis in comparison to those patients with metabolic syndrome (58.7% vs. 39.1%; ppancreatitis. Comparing survival rates, patients suffering from metabolic syndrome had a higher death rate compared to patients without metabolic syndrome (16% vs. 4.5%; ppancreatitis, as well as higher mortality rate. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  15. Cancer Metabolism: A Modeling Perspective

    DEFF Research Database (Denmark)

    Ghaffari, Pouyan; Mardinoglu, Adil; Nielsen, Jens

    2015-01-01

    Tumor cells alter their metabolism to maintain unregulated cellular proliferation and survival, but this transformation leaves them reliant on constant supply of nutrients and energy. In addition to the widely studied dysregulated glucose metabolism to fuel tumor cell growth, accumulating evidenc...

  16. Evolution of Microbial “Streamer” Growths in an Acidic, Metal-Contaminated Stream Draining an Abandoned Underground Copper Mine

    Directory of Open Access Journals (Sweden)

    Catherine M. Kay

    2013-02-01

    Full Text Available A nine year study was carried out on the evolution of macroscopic “acid streamer” growths in acidic, metal-rich mine water from the point of construction of a new channel to drain an abandoned underground copper mine. The new channel became rapidly colonized by acidophilic bacteria: two species of autotrophic iron-oxidizers (Acidithiobacillus ferrivorans and “Ferrovum myxofaciens” and a heterotrophic iron-oxidizer (a novel genus/species with the proposed name “Acidithrix ferrooxidans”. The same bacteria dominated the acid streamer communities for the entire nine year period, with the autotrophic species accounting for ~80% of the micro-organisms in the streamer growths (as determined by terminal restriction enzyme fragment length polymorphism (T-RFLP analysis. Biodiversity of the acid streamers became somewhat greater in time, and included species of heterotrophic acidophiles that reduce ferric iron (Acidiphilium, Acidobacterium, Acidocella and gammaproteobacterium WJ2 and other autotrophic iron-oxidizers (Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans. The diversity of archaea in the acid streamers was far more limited; relatively few clones were obtained, all of which were very distantly related to known species of euryarchaeotes. Some differences were apparent between the acid streamer community and planktonic-phase bacteria. This study has provided unique insights into the evolution of an extremophilic microbial community, and identified several novel species of acidophilic prokaryotes.

  17. Dynamic of active microorganisms inhabiting a bioleaching industrial heap of low‐grade copper sulfide ore monitored by real‐time PCR and oligonucleotide prokaryotic acidophile microarray

    Science.gov (United States)

    Remonsellez, Francisco; Galleguillos, Felipe; Moreno‐Paz, Mercedes; Parro, Víctor; Acosta, Mauricio; Demergasso, Cecilia

    2009-01-01

    Summary The bioleaching of metal sulfide has developed into a very important industrial process and understanding the microbial dynamic is key to advancing commercial bioleaching operations. Here we report the first quantitative description of the dynamic of active communities in an industrial bioleaching heap. Acidithiobacillus ferrooxidans was the most abundant during the first part of the leaching cycle, while the abundance of Leptospirillum ferriphilum and Ferroplasma acidiphilum increased with age of the heap. Acidithiobacillus thiooxidans kept constant throughout the leaching cycle, and Firmicutes group showed a low and a patchy distribution in the heap. The Acidiphilium‐like bacteria reached their highest abundance corresponding to the amount of autotrophs. The active microorganisms in the leaching system were determined using two RNA‐based sensitive techniques. In most cases, the 16S rRNA copy numbers of At. ferrooxidans, L. ferriphilum, At. thiooxidans and F. acidiphilum, was concomitant with the DNA copy numbers, whereas Acidiphilium‐like bacteria and some Firmicutes members did not show a clear correlation between 16S rRNA accumulation and DNA copy numbers. However, the prokaryotic acidophile microarray (PAM) analysis showed active members of Alphaproteobacteria in all samples and of Sulfobacillus genus in older ones. Also, new active groups such as Actinobacteria and Acidobacterium genus were detected by PAM. The results suggest that changes during the leaching cycle in chemical and physical conditions, such as pH and Fe3+/Fe2+ ion rate, are primary factors shaping the microbial dynamic in the heap. PMID:21255296

  18. Evolution of Microbial “Streamer” Growths in an Acidic, Metal-Contaminated Stream Draining an Abandoned Underground Copper Mine

    Science.gov (United States)

    Kay, Catherine M.; Rowe, Owen F.; Rocchetti, Laura; Coupland, Kris; Hallberg, Kevin B.; Johnson, D. Barrie

    2013-01-01

    A nine year study was carried out on the evolution of macroscopic “acid streamer” growths in acidic, metal-rich mine water from the point of construction of a new channel to drain an abandoned underground copper mine. The new channel became rapidly colonized by acidophilic bacteria: two species of autotrophic iron-oxidizers (Acidithiobacillus ferrivorans and “Ferrovum myxofaciens”) and a heterotrophic iron-oxidizer (a novel genus/species with the proposed name “Acidithrix ferrooxidans”). The same bacteria dominated the acid streamer communities for the entire nine year period, with the autotrophic species accounting for ~80% of the micro-organisms in the streamer growths (as determined by terminal restriction enzyme fragment length polymorphism (T-RFLP) analysis). Biodiversity of the acid streamers became somewhat greater in time, and included species of heterotrophic acidophiles that reduce ferric iron (Acidiphilium, Acidobacterium, Acidocella and gammaproteobacterium WJ2) and other autotrophic iron-oxidizers (Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans). The diversity of archaea in the acid streamers was far more limited; relatively few clones were obtained, all of which were very distantly related to known species of euryarchaeotes. Some differences were apparent between the acid streamer community and planktonic-phase bacteria. This study has provided unique insights into the evolution of an extremophilic microbial community, and identified several novel species of acidophilic prokaryotes. PMID:25371339

  19. Metabolic management of heart disease

    Directory of Open Access Journals (Sweden)

    Akshyaya K Pradhan

    2016-01-01

    Full Text Available Alterations of cardiac metabolism occur with ischemia and heart failure (HF. This results in increased utilization of noncarbohydrate substrates for energy production and depletion of myocardial adenosine triphosphate, phosphocreatine, and creatine kinase with decreased efficiency of mechanical work. A direct approach to manipulate cardiac energy metabolism consists in modifying substrate utilization by the failing heart. The results of research suggest that shifting the energy substrate preference away from fatty acid metabolism and toward glucose metabolism could be an effective adjunctive treatment in patients with HF, in terms of left ventricular function and glucose metabolism improvement. In this paper, some of these concepts will be discussed, and the role of drugs such as trimetazidine will be discussed.

  20. Metabolic effects of renal denervation.

    Science.gov (United States)

    Thomopoulos, Costas; Spanoudi, Filio; Kyriazis, Ioannis; Anastasopoulos, Ioannis; Ioannidis, Ioannis

    2013-08-01

    In the present review article we address the issue of the potential effect of renal sympathetic denervation (RSD) on metabolic states associated with resistant hypertension. So far, there is an established pathophysiological background denoting that abnormalities in glucose metabolism especially in obese patients and in those with sleep apnea are constantly accompanied by increased sympathetic firing, as assessed by markers of sympathetic activity. Since resistant hypertension is also characterized by enhanced sympathetic activity, it seems logical and biologically plausible, that RSD might favorably influence impaired glucose metabolism, sleep disorders and increased body adiposity beyond BP lowering. Despite the limited evidence from clinical trials, there are promising data suggesting that RSD indeed ameliorates glucose metabolism-related measures in resistant hypertension. Well-designed randomized trials recruiting a larger number of patients with hypertension, and focused on metabolic parameters, may refine the role of RSD as a potential intervention to treat dysmetabolic states associated with hypertension.

  1. Retinoid Metabolism and Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Eun-Jung Rhee

    2012-06-01

    Full Text Available Retinoid acid is a metabolite of vitamin A and functions as an important factor in cell survival, differentiation and death. Most previous studies on retinoid metabolism have focused on its association with cancer, hematologic and dermatologic disorders. Given the special concern over the recent increase in the prevalence of diabetes worldwide, the role of retinoid metabolism on glucose metabolism and insulin resistance in the human body is of marked importance. Therefore, in this issue, we review the literature on the association of retinoid metabolism with glucose tolerance, with regard to insulin secretion, pancreatic autoimmunity, insulin sensitivity and lipid metabolism. Further, we tried to assess the possibility of using retinoids as a novel therapeutic strategy for diabetes.

  2. Vasomotor symptoms and metabolic syndrome.

    Science.gov (United States)

    Tuomikoski, Pauliina; Savolainen-Peltonen, Hanna

    2017-03-01

    A vast majority of menopausal women suffer from vasomotor symptoms, such as hot flushes and night sweats, the mean duration of which may be up to 7-10 years. In addition to a decreased quality of life, vasomotor symptoms may have an impact on overall health. Vasomotor symptoms are associated with overactivity of the sympathetic nervous system, and sympathetic overdrive in turn is associated with metabolic syndrome, which is a known risk factor for cardiovascular disease. Menopausal hot flushes have a complex relationship to different features of the metabolic syndrome and not all data point towards an association between vasomotor symptoms and metabolic syndrome. Thus, it is still unclear whether vasomotor symptoms are an independent risk factor for metabolic syndrome. Research in this area is constantly evolving and we present here the most recent data on the possible association between menopausal vasomotor symptoms and the metabolic syndrome. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The metabolic switch of cancer

    Directory of Open Access Journals (Sweden)

    Yuting Ma

    2017-03-01

    Full Text Available Although remarkable progress has been made in oncology research, cancer is still a leading cause of death worldwide. It is well recognized that cancer is a genetic disease, yet metabolic alterations or reprogramming are the major phenotypes associated with the (epi-genetic modifications of cancer cells. Thus, understanding the metabolic changes of tumor cells will facilitate the diagnosis of cancer, alleviate drug resistance and provide novel druggable targets that can lead to cures for cancer. The first Sino-US Symposium on Cancer Metabolism was held in Chongqing on October 10th and 11th, with the theme of “cancer metabolism and precision cancer therapy”. The symposium brought about a dozen keynote speakers each from the US and mainland China, as well as one hundred delegates with an interest in cancer metabolism. This short article will briefly summarize the advances reported during this meeting.

  4. [Hypovitaminosis D and metabolic syndrome].

    Science.gov (United States)

    Miñambres, Inka; de Leiva, Alberto; Pérez, Antonio

    2014-12-23

    Metabolic syndrome and hypovitaminosis D are 2 diseases with high prevalence that share several risk factors, while epidemiological evidence shows they are associated. Although the mechanisms involved in this association are not well established, hypovitaminosis D is associated with insulin resistance, decreased insulin secretion and activation of the renin-angiotensin system, mechanisms involved in the pathophysiology of metabolic syndrome. However, the apparent ineffectiveness of vitamin D supplementation on metabolic syndrome components, as well as the limited information about the effect of improving metabolic syndrome components on vitamin D concentrations, does not clarify the direction and the mechanisms involved in the causal relationship between these 2 pathologies. Overall, because of the high prevalence and the epidemiological association between both diseases, hypovitaminosis D could be considered a component of the metabolic syndrome. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  5. Metabolic memory: Evolving concepts.

    Science.gov (United States)

    Misra, Anoop; Bloomgarden, Zachary

    2018-03-01

    The relationships of glycemic control over time with the development of complications have been investigated in several studies, but new areas of debate continue to arise. Does glycemic control have greater benefit when attained earlier than when attained later in the natural history of diabetes? Is it simply the duration of better or worse levels of glycemia that lead a given individual to have fewer or greater levels of complications? Might glycemic control have similar benefit throughout the duration of diabetes until irreversible damage occurs, perhaps varying by organ system (neurologic, renal, retinal, cardiovascular)? Specific benefits or adverse effects of treatment agents may further complicate the interpretation of what has been characterized as "metabolic memory." The notion of metabolic memory was based on findings of the Diabetes Control and Complications Trial (DCCT) of type 1 diabetes (T1D), in which the initial 2% HbA1c separation between the groups of patients randomized to intensive or conventional control was lost during the follow up Epidemiology of Diabetes Interventions and Complications (EDIC) study, when the two groups of participants returned to standard treatment and showed similar HbA1c levels but the initial intensively treated group continued to have lower rates of development of microvascular and, subsequently, macrovascular complications. Similarly, a decade after the conclusion of the UK Prospective Diabetes Study (UKPDS), patients with type 2 diabetes (T2D) in the intensive therapy group, despite showing similar levels of glycemic control to those receiving standard care, continued to have significant reductions in microvascular endpoints and reductions in myocardial infarction and all-cause mortality. A 6-year follow up of the Veteran's Administration Diabetes Trial suggested that the formerly intensively controlled subset were more likely to maintain an estimated glomerular filtration rate >60 ml/min/1.73m 2 than those randomized

  6. Metabolic Surgery Profoundly Influences Gut Microbial-Host Metabolic Crosstalk

    Science.gov (United States)

    Li, Jia V.; Ashrafian, Hutan; Bueter, Marco; Kinross, James; Sands, Caroline; le Roux, Carel W; Bloom, Stephen R.; Darzi, Ara; Athanasiou, Thanos; Marchesi, Julian R.; Nicholson, Jeremy K.; Holmes, Elaine

    2013-01-01

    Background and Aims Bariatric surgery is increasingly performed worldwide to treat morbid obesity and is also known as metabolic surgery to reflect its beneficial metabolic effects especially with respect to improvement in type 2 diabetes. Understanding surgical weight loss mechanisms and metabolic modulation is required to enhance patient benefits and operative outcomes. Methods We apply a parallel and statistically integrated metagenomic and metabonomic approach to characterize Roux-en-Y gastric bypass (RYGB) effects in a rat model. Results We show substantial shifts of the main gut phyla towards higher levels of Proteobacteria (52-fold) specifically Enterobacter hormaechei. We also find low levels of Firmicutes (4.5-fold) and Bacteroidetes (2-fold) in comparison to sham-operated rats. Faecal extraction studies reveal a decrease in faecal bile acids and a shift from protein degradation to putrefaction through decreased faecal tyrosine with concomitant increases in faecal putrescine and diamnoethane. We find decreased urinary amines and cresols and demonstrate indices of modulated energy metabolism post-RYGB including decreased urinary succinate, 2-oxoglutarate, citrate and fumarate. These changes could also indicate renal tubular acidosis, which associates with increased flux of mitochondrial tricarboxylic acid cycle intermediates. A surgically-induced effect on the gut-brain-liver metabolic axis is inferred by increased neurotropic compounds; faecal γ-aminobutyric acid (GABA) and glutamate. Conclusion This profound co-dependence of mammalian and microbial metabolism, which is systematically altered following RYGB surgery, suggests that RYGB exerts local and global metabolic activities. The effect of RYGB surgery on the host metabolic-microbial crosstalk augments our understanding of the metabolic phenotype of bariatric procedures and can facilitate enhanced treatments for obesity-related diseases. PMID:21572120

  7. [Electrolyte metabolism and emergency].

    Science.gov (United States)

    Nakao, I; Ito, T; Kasai, N

    1983-02-01

    In outlining the pathology of various electrolyte metabolism abnormalities in cancer patients we considered the main clinical points between pathologies and emergency treatment. In regard to sodium (Na+) metabolism, one pathologic state that requires our attention is hypernatremia. Hypernatremia is accompanied with dehydration and is due to water loss, vomiting, diarrhea and renal insufficiency. One of the major causes of this condition is lack of the antidiuretic hormone due to intracranial metastasis of the tumor. When hypernatremia becomes severe, it is accompanied with circulatory failure, muscular asthenia, disorientation, convulsions, coma and other cerebral symptoms. Treatment consists of replenishing the water content by infusion of electrolyte solutions which should be carefully conducted after complete diagnose of the severity of the patient's pathological condition. Hyponatremia, like sick cell syndrome, is observed relatively frequently in cancer patients. When the serum Na level falls markedly, it induces cerebral edema and causes disorders of consciousness. The major treatment consists of providing both water and sodium supplements. Hyperkalemia is observed at the time of renal insufficiency, tissue lesions, vomiting, and diarrhea. When serum potassium level rises, it causes bradycardia, ventricular fibrillation, or cardiac arrest. It is important to diagnostically apprehend the severity of this condition using EKG and determining the serum K1+ level. For emergency treatment injection of calcium gluconate is very effective. Hypokalemia is often manifested by the loss of intestinal fluids due to diarrhea or during administration of diuretic agents. Clinical symptoms include neural paralysis but emergencies occur relatively infrequently. K C1 injections are used in treating this condition. Hypercalcemia is manifested in cancer patients during hyperparathyroidism. Its clinical symptoms include lassitude, tachycardia, nausea, vomiting, and renal dys

  8. Microbial metabolism of tholin

    Science.gov (United States)

    Stoker, C. R.; Boston, P. J.; Mancinelli, R. L.; Segal, W.; Khare, B. N.; Sagan, C.

    1990-05-01

    In this paper, we show that a wide variety of common soil bacteria are able to obtain their carbon and energy needs from tholin (a class of complex organic heteropolymers thought to be widely distributed through the solar system; in this case tholin was produced by passage of electrical discharge through a mixture of methane, ammonia, and water vapor). We have isolated aerobic, anaerobic, and facultatively anaerobic bacteria which are able to use tholin as a sole carbon source. Organisms which metabolize tholin represent a variety of bacterial genera including Clostridium, Pseudomonas, Bacillus, Acinetobacter, Paracoccus, Alcaligenes, Micrococcus, Cornebacterium, Aerobacter, Arthrobacter, Flavobacterium,and Actinomyces. Aerobic tholin-using bacteria were firrst isolated from soils containing unusual or sparse carbon sources. Some of these organisms were found to be facultatively anaerobic. Strictly anaerobic tholin-using bacteria were isolated from both carbon-rich and carbon-poor anaerobic lake muds. In addition, both aerobic and anaerobic tholin-using bacteria were isolated from common soil collected outside the laboratory building. Some, but not all, of the strains that were able to obtain carbon from tholin were also able to obtain their nitrogen requirements from tholin. Bacteria isolated from common soils were tested for their ability to obtain carbon from the water-soluble fraction, the ethanol-soluble fraction, and the water/ethanol-insoluble fraction of the tholin. Of the 3.5 × 10 7 bacteria isolated per gram of common soils, 1.7 0.5, and 0.2%, respectively, were able to obtaib their carbon requirements from the water-soluble fraction, the ethanol-soluble fraction and the water/ethanol-insoluble fraction of the tholin. The palatability of tholins to modern microbes may have implications for the early evolution of microbial life on Earth. Tholins may have formed the base of the food chain for an early heterotrophic biosphere before the evolution of

  9. Treatment of Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... amino acid metabolism disorders Treatment of amino acid metabolism disorders E-mail to a friend Please fill ... It's been added to your dashboard . Amino acid metabolism disorders are rare health conditions that affect a ...

  10. Simulation of acid mine drainage generation around Küre VMS Deposits, Northern Turkey

    Science.gov (United States)

    Demirel, Cansu; Kurt, Mehmet Ali; Çelik Balci, Nurgül

    2015-04-01

    This study investigated comparative leaching characteristics of acidophilic bacterial strains under shifting environmental conditions at proposed two stages as formation stage or post acidic mine drainage (AMD) generation. At the first stage, initial reactions associated with AMD generation was simulated in shaking flasks containing massive pyritic chalcopyrite ore by using a pure strain Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus sp. mostly dominated by A. ferrooxidans and A. thiooxidans at 26oC. At the second stage, long term bioleaching experiments were carried out with the same strains at 26oC and 40oC to investigate the leaching characteristics of pyritic chalcopyrite ore under elevated heavy metal and temperature conditions. During the experiments, physicochemical characteristics (e.i. Eh, pH, EC) metal (Fe, Co, Cu, Zn) and sulfate concentration of the experimental solution were monitored during 180 days. Significant acid generation and sulfate release were determined during bioleaching of the ore by mixed acidophilic cultures containing both iron and sulfur oxidizers. In the early stage of the experiments, heavy metal release from the ore was caused by generation of acid due to accelerated bacterial oxidation of the ore. Generally high concentrations of Co and Cu were released into the solution from the experiments conducted by pure cultures of Acidithiobacillus ferrooxidans whereas high Zn and Fe was released into the solution from the mixed culture experiments. In the later stage of AMD generation and post AMD, chemical oxidation is accelerated causing excessive amounts of contamination, even exceeding the amounts resulted from bacterial oxidation by mixed cultures. Acidithibacillus ferrooxidans was found to be more effective in leaching Cu, Fe and Co at higher temperatures in contrary to mixed acidophiles that are more prone to operate at optimal moderate conditions. Moreover, decreasing Fe values are noted in bioleaching

  11. Xenobiotic Metabolism and Gut Microbiomes.

    Directory of Open Access Journals (Sweden)

    Anubhav Das

    Full Text Available Humans are exposed to numerous xenobiotics, a majority of which are in the form of pharmaceuticals. Apart from human enzymes, recent studies have indicated the role of the gut bacterial community (microbiome in metabolizing xenobiotics. However, little is known about the contribution of the plethora of gut microbiome in xenobiotic metabolism. The present study reports the results of analyses on xenobiotic metabolizing enzymes in various human gut microbiomes. A total of 397 available gut metagenomes from individuals of varying age groups from 8 nationalities were analyzed. Based on the diversities and abundances of the xenobiotic metabolizing enzymes, various bacterial taxa were classified into three groups, namely, least versatile, intermediately versatile and highly versatile xenobiotic metabolizers. Most interestingly, specific relationships were observed between the overall drug consumption profile and the abundance and diversity of the xenobiotic metabolizing repertoire in various geographies. The obtained differential abundance patterns of xenobiotic metabolizing enzymes and bacterial genera harboring them, suggest their links to pharmacokinetic variations among individuals. Additional analyses of a few well studied classes of drug modifying enzymes (DMEs also indicate geographic as well as age specific trends.

  12. Metabolic syndrome in androgenic alopecia.

    Science.gov (United States)

    Gopinath, Hima; Upadya, Gatha M

    2016-01-01

    Androgenic alopecia has been associated with an increased risk of coronary heart disease in various studies. The relationship between androgenic alopecia and metabolic syndrome, a known risk factor for atherosclerotic cardiovascular disease, is still poorly understood. To study the association between metabolic syndrome and early-onset androgenic alopecia. A hospital-based analytical cross-sectional study was done on men in the age group of 18-55 years. Eighty five clinically diagnosed cases with early-onset (alopecia of Norwood grade III or above, and 85 controls without androgenic alopecia were included. Data collected included anthropometric measurements, arterial blood pressure and history of chronic diseases. Fasting blood and lipid profile were determined. Metabolic syndrome was diagnosed as per the new International Diabetes Federation criteria. Chi-square and Student's t-test were used for statistical analysis using Statistical Package for the Social Sciences (SPSS) version 17.00. Metabolic syndrome was seen in 19 (22.4%) patients with androgenic alopecia and 8 (9.4%) controls (P = 0.021). Abdominal obesity, hypertension and lowered high-density lipoprotein were significantly higher in patients with androgenic alopecia versus their respective controls. The limitations of our study include small sample size in subgroups and the lack of evidence of a temporal relationship between metabolic syndrome and androgenic alopecia. A higher prevalence of metabolic syndrome is seen in men with early-onset androgenic alopecia. Early screening for metabolic syndrome and its components is beneficial in patients with early-onset androgenic alopecia.

  13. Cancer metabolism: a modeling perspective

    Directory of Open Access Journals (Sweden)

    Pouyan eGhaffari Nouran

    2015-12-01

    Full Text Available Tumor cells alter their metabolism to maintain unregulated cellular proliferation and survival, but this transformation leaves them reliant on constant supply of nutrients and energy. In addition to the widely studied dysregulated glucose metabolism to fuel tumor cell growth, accumulating evidences suggest that utilization of amino acids and lipids contributes significantly to cancer cell metabolism. Also recent progresses in our understanding of carcinogenesis have revealed that cancer is a complex disease and cannot be understood through simple investigation of genetic mutations of cancerous cells. Cancer cells present in complex tumor tissues communicate with the surrounding microenvironment and develop traits which promote their growth, survival and metastasis. Decoding the full scope and targeting dysregulated metabolic pathways that support neoplastic transformations and their preservation requires both the advancement of experimental technologies for more comprehensive measurement of omics as well as the advancement of robust computational methods for accurate analysis of the generated data. Here, we review cancer-associated reprogramming of metabolism and highlight the capability of genome-scale metabolic modeling approaches in perceiving a system-level perspective of cancer metabolism and in detecting novel selective drug targets

  14. Physics of metabolic organization

    Science.gov (United States)

    Jusup, Marko; Sousa, Tânia; Domingos, Tiago; Labinac, Velimir; Marn, Nina; Wang, Zhen; Klanjšček, Tin

    2017-03-01

    We review the most comprehensive metabolic theory of life existing to date. A special focus is given to the thermodynamic roots of this theory and to implications that the laws of physics-such as the conservation of mass and energy-have on all life. Both the theoretical foundations and biological applications are covered. Hitherto, the foundations were more accessible to physicists or mathematicians, and the applications to biologists, causing a dichotomy in what always should have been a single body of work. To bridge the gap between the two aspects of the same theory, we (i) adhere to the theoretical formalism, (ii) try to minimize the amount of information that a reader needs to process, but also (iii) invoke examples from biology to motivate the introduction of new concepts and to justify the assumptions made, and (iv) show how the careful formalism of the general theory enables modular, self-consistent extensions that capture important features of the species and the problem in question. Perhaps the most difficult among the introduced concepts, the utilization (or mobilization) energy flow, is given particular attention in the form of an original and considerably simplified derivation. Specific examples illustrate a range of possible applications-from energy budgets of individual organisms, to population dynamics, to ecotoxicology.

  15. Physics of metabolic organization.

    Science.gov (United States)

    Jusup, Marko; Sousa, Tânia; Domingos, Tiago; Labinac, Velimir; Marn, Nina; Wang, Zhen; Klanjšček, Tin

    2017-03-01

    We review the most comprehensive metabolic theory of life existing to date. A special focus is given to the thermodynamic roots of this theory and to implications that the laws of physics-such as the conservation of mass and energy-have on all life. Both the theoretical foundations and biological applications are covered. Hitherto, the foundations were more accessible to physicists or mathematicians, and the applications to biologists, causing a dichotomy in what always should have been a single body of work. To bridge the gap between the two aspects of the same theory, we (i) adhere to the theoretical formalism, (ii) try to minimize the amount of information that a reader needs to process, but also (iii) invoke examples from biology to motivate the introduction of new concepts and to justify the assumptions made, and (iv) show how the careful formalism of the general theory enables modular, self-consistent extensions that capture important features of the species and the problem in question. Perhaps the most difficult among the introduced concepts, the utilization (or mobilization) energy flow, is given particular attention in the form of an original and considerably simplified derivation. Specific examples illustrate a range of possible applications-from energy budgets of individual organisms, to population dynamics, to ecotoxicology. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. 'Sarcobesity': a metabolic conundrum.

    Science.gov (United States)

    Parr, Evelyn B; Coffey, Vernon G; Hawley, John A

    2013-02-01

    Two independent but inter-related conditions that have a growing impact on healthy life expectancy and health care costs in developed nations are an age-related loss of muscle mass (i.e., sarcopenia) and obesity. Sarcopenia is commonly exacerbated in overweight and obese individuals. Progression towards obesity promotes an increase in fat mass and a concomitant decrease in muscle mass, producing an unfavourable ratio of fat to muscle. The coexistence of diminished muscle mass and increased fat mass (so-called 'sarcobesity') is ultimately manifested by impaired mobility and/or development of life-style-related diseases. Accordingly, the critical health issue for a large proportion of adults in developed nations is how to lose fat mass while preserving muscle mass. Lifestyle interventions to prevent or treat sarcobesity include energy-restricted diets and exercise. The optimal energy deficit to reduce body mass is controversial. While energy restriction in isolation is an effective short-term strategy for rapid and substantial weight loss, it results in a reduction of both fat and muscle mass and therefore ultimately predisposes one to an unfavourable body composition. Aerobic exercise promotes beneficial changes in whole-body metabolism and reduces fat mass, while resistance exercise preserves lean (muscle) mass. Current evidence strongly supports the inclusion of resistance and aerobic exercise to complement mild energy-restricted high-protein diets for healthy weight loss as a primary intervention for sarcobesity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. [Regulation of terpene metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.

    1991-01-01

    During the last grant period, we have completed studies on the key pathways of monoterpene biosynthesis and catabolism in sage and peppermint, and have, by several lines of evidence, deciphered the rate-limiting step of each pathway. We have at least partially purified and characterized the relevant enzymes of each pathway. We have made a strong case, based on analytical, in vivo, and in vitro studies, that terpene accumulation depends upon the balance between biosynthesis and catabolism, and provided supporting evidence that these processes are developmentally-regulated and very closely associated with senescence of the oil glands. Oil gland ontogeny has been characterized at the ultrastructural level. We have exploited foliar-applied bioregulators to delay gland senescence, and have developed tissue explant and cell culture systems to study several elusive aspects of catabolism. We have isolated pure gland cell clusters and localized monoterpene biosynthesis and catabolism within these structures, and have used these preparations as starting materials for the purification to homogeneity of target regulatory'' enzymes. We have thus developed the necessary background knowledge, based on a firm understanding of enzymology, as well as the necessary experimental tools for studying the regulation of monoterpene metabolism at the molecular level. Furthermore, we are now in a position to extend our systematic approach to other terpenoid classes (C[sub 15]-C[sub 30]) produced by oil glands.

  18. [Metabolic safety of antidepressant medicines].

    Science.gov (United States)

    Łężak, Wojciech; Mokros, Łukasz; Karbownik, Michał Seweryn; Witusik, Andrzej; Kosmalski, Marcin; Kowalczyk, Edward; Pietras, Tadeusz

    2017-05-23

    Metabolic syndrome is a very serious health issue, not only from internal medicine's point of view. Patients suffering from overweight, arterial hypertension, lipids and carbohydrates metabolism disorders are also in the circle of interest of other areas of medicine, including psychiatry. Currently, one of key problems of pharmacotherapy is a comorbidity of metabolic syndrome and mental disorder. Depression is more common than schizophrenia. Despite the fact that in everyday clinical practice there are more patients with depression than schizophrenia, there is a bigger interest among scientists for metabolic syndrome after antipsychotic drugs than as an effect of use of antidepressant agents. The aim of an analysis was to review literature committed to influence of depression pharmacotherapy on development of metabolic syndrome. 169 results were provided, including 18 original publications. Final analysis consists of 9 that investigate correlation between antidepressive medicines use and metabolic syndrome development (but not its each individual component). In general, antidepressant pharmacotherapy is associated not only with increased risk of metabolic syndrome occurrence but also their worsening. However, it needs to be emphasized that there is a difference between antidepressants groups - tricyclic antidepressive medicines are the most commonly associated with risk of developing metabolic disorders, but also SNRIs and SSRIs are mentioned as significant contributors. Mechanisms of aforementioned changes are still unclear. However, their influence on histamine and serotonin pathways, which take part in regulation of i.e. food intake, is suggested. The search for mechanisms that are precisely responsible for metabolic changes continues, in hope of finding a way to avoid adverse effects of antidepressant medicines use.

  19. Cardiac metabolism in myocardial ischemia.

    Science.gov (United States)

    Rosano, Giuseppe M C; Fini, Massimo; Caminiti, Giuseppe; Barbaro, Giuseppe

    2008-01-01

    Myocardial ischemia occurs for a mismatch between blood flow and metabolic requirements, when the rate of oxygen and metabolic substrates delivery to the myocardium is insufficient to meet the myocardial energy requirements for a given myocardial workload. During ischemia, substantial changes occur in cardiac energy metabolism, as a consequence of the reduced oxygen availability. Some of these metabolic changes are beneficial and may help the heart adapt to the ischemic condition. However, most of the changes are maladaptive and contribute to the severity of the ischemic injury leading stunned or hibernating myocardium, cell death and ultimately to contractile disfunction. Dramatic changes in cardiac metabolism and contractile function, also occur during myocardial reperfusion as a consequence of the generation of oxygen free radicals, loss of cation homeostasis, depletion of energy stores, and changes in subcellular activities. The reperfusion injury may cause in the death of cardiac myocytes that were still viable immediately before myocardial reperfusion. This form of myocardial injury, by itself can induce cardiomyocyte death and increase infarct size. During acute ischemia the relative substrate concentration is the prime factor defining preference and utilization rate. Allosteric enzyme regulation and protein phosphorylation cascades, partially controlled by hormones such as insulin, modulate the concentration effect; together they provide short-term adjustments of cardiac energy metabolism. The expression of metabolic genes is also dynamically regulated in response to developmental and (patho)physiological conditions, leading to long-term adjustments. Specific nuclear receptor transcription factors and co-activators regulate the expression of these genes. Understanding the functional role of these changes is critical for developing the concept of metabolic intervention for heart disease. The paper will review the alterations in energy metabolism that occur

  20. MicroRNAs in Metabolism and Metabolic Disorders

    Science.gov (United States)

    Rottiers, Veerle; Näär, Anders M.

    2014-01-01

    MicroRNAs (miRNAs) have recently emerged as key regulators of metabolism. For example, miR-33a and b play a crucial role in controlling cholesterol and lipid metabolism in concert with their host genes, the SREBP transcription factors. Metabolic miRNAs such as miR-103 and miR-107 regulate insulin and glucose homeostasis, while others, such as miR-34a, may be key regulators of hepatic lipid homeostasis. The discovery of circulating miRNAs has highlighted their potential as both endocrine signalling molecules and disease markers. Dysregulation of miRNAs may contribute to metabolic abnormalities, suggesting that miRNAs may potentially serve as therapeutic targets to ameliorate cardiometabolic disorders. PMID:22436747

  1. Metabolic interrelationships software application: Interactive learning tool for intermediary metabolism*.

    Science.gov (United States)

    Verhoeven, Adrie J M; Doets, Mathijs; Lamers, Jos M J; Koster, Johan F

    2005-11-01

    We developed and implemented the software application titled Metabolic Interrelationships as a self-learning and -teaching tool for intermediary metabolism. It is used by undergraduate medical students in an integrated organ systems-based and disease-oriented core curriculum, which started in our medical faculty in 2001. The computer program provides an interactive environment in which students learn to integrate the major metabolic pathways as well as their hormonal control mechanisms as far as they depend on nutritional status. Students can explore the time- and tissue-dependent changes in mammalian intermediary metabolism during a feeding-fasting cycle. Starting from a whole-body view of interorgan nutrient fluxes, the student can make excursions to individual organs and, from there, to increasing levels of molecular detail and to explanatory animations. The application is well received by students and staff. Copyright © 2005 International Union of Biochemistry and Molecular Biology, Inc.

  2. Metabolic Programming in the Immediate Postnatal Life

    National Research Council Canada - National Science Library

    Patel, Mulchand S; Srinivasan, Malathi

    2011-01-01

    The metabolic programming effects of nutritional modifications in the immediate postnatal life are increasingly recognized to independently contribute to the development of metabolic syndrome in later life...

  3. Ocular associations of metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Rupali Chopra

    2012-01-01

    Full Text Available Metabolic syndrome is a cluster of diseases including central obesity, dyslipidemia, hyperglycemia, and high blood pressure. People with metabolic syndrome have been shown to be at an increased risk of developing cardiovascular disease, beyond the risk associated with individual components of the syndrome. The association of diabetes and hypertension with retinopathy, cataract, and raised intraocular pressure is well known. This review highlights the association of metabolic syndrome, including all its components, with various ocular conditions such as retinopathy, central retinal artery occlusion, cataracts, and raised intraocular pressure.

  4. Interrogating Metabolism in Brain Cancer.

    Science.gov (United States)

    Salzillo, Travis C; Hu, Jingzhe; Nguyen, Linda; Whiting, Nicholas; Lee, Jaehyuk; Weygand, Joseph; Dutta, Prasanta; Pudakalakatti, Shivanand; Millward, Niki Zacharias; Gammon, Seth T; Lang, Frederick F; Heimberger, Amy B; Bhattacharya, Pratip K

    2016-11-01

    This article reviews existing and emerging techniques of interrogating metabolism in brain cancer from well-established proton magnetic resonance spectroscopy to the promising hyperpolarized metabolic imaging and chemical exchange saturation transfer and emerging techniques of imaging inflammation. Some of these techniques are at an early stage of development and clinical trials are in progress in patients to establish the clinical efficacy. It is likely that in vivo metabolomics and metabolic imaging is the next frontier in brain cancer diagnosis and assessing therapeutic efficacy; with the combined knowledge of genomics and proteomics a complete understanding of tumorigenesis in brain might be achieved. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Analysis of metabolic flux using dynamic labeling and metabolic modeling

    OpenAIRE

    Fernie, A.; Morgan, J.

    2013-01-01

    Metabolic fluxes and the capacity to modulate them are a crucial component of the ability of the plant cell to react to environmental perturbations. Our ability to quantify them and to attain information concerning the regulatory mechanisms which control them is therefore essential to understand and influence metabolic networks. For all but the simplest of flux measurements labelling methods have proven to be the most informative. Both steady-state and dynamic labelling approaches having been...

  6. Metabolic network visualization eliminating node redundance and preserving metabolic pathways

    Directory of Open Access Journals (Sweden)

    Sagot Marie-France

    2007-07-01

    Full Text Available Abstract Background The tools that are available to draw and to manipulate the representations of metabolism are usually restricted to metabolic pathways. This limitation becomes problematic when studying processes that span several pathways. The various attempts that have been made to draw genome-scale metabolic networks are confronted with two shortcomings: 1- they do not use contextual information which leads to dense, hard to interpret drawings, 2- they impose to fit to very constrained standards, which implies, in particular, duplicating nodes making topological analysis considerably more difficult. Results We propose a method, called MetaViz, which enables to draw a genome-scale metabolic network and that also takes into account its structuration into pathways. This method consists in two steps: a clustering step which addresses the pathway overlapping problem and a drawing step which consists in drawing the clustered graph and each cluster. Conclusion The method we propose is original and addresses new drawing issues arising from the no-duplication constraint. We do not propose a single drawing but rather several alternative ways of presenting metabolism depending on the pathway on which one wishes to focus. We believe that this provides a valuable tool to explore the pathway structure of metabolism.

  7. Plant Metabolic Modeling: Achieving New Insight into Metabolism and Metabolic Engineering

    Science.gov (United States)

    Baghalian, Kambiz; Hajirezaei, Mohammad-Reza; Schreiber, Falk

    2014-01-01

    Models are used to represent aspects of the real world for specific purposes, and mathematical models have opened up new approaches in studying the behavior and complexity of biological systems. However, modeling is often time-consuming and requires significant computational resources for data development, data analysis, and simulation. Computational modeling has been successfully applied as an aid for metabolic engineering in microorganisms. But such model-based approaches have only recently been extended to plant metabolic engineering, mainly due to greater pathway complexity in plants and their highly compartmentalized cellular structure. Recent progress in plant systems biology and bioinformatics has begun to disentangle this complexity and facilitate the creation of efficient plant metabolic models. This review highlights several aspects of plant metabolic modeling in the context of understanding, predicting and modifying complex plant metabolism. We discuss opportunities for engineering photosynthetic carbon metabolism, sucrose synthesis, and the tricarboxylic acid cycle in leaves and oil synthesis in seeds and the application of metabolic modeling to the study of plant acclimation to the environment. The aim of the review is to offer a current perspective for plant biologists without requiring specialized knowledge of bioinformatics or systems biology. PMID:25344492

  8. Redesigned Human Metabolic Simulator

    Science.gov (United States)

    Duffield, Bruce; Jeng, Frank; Lange, Kevin

    2008-01-01

    A design has been formulated for a proposed improved version of an apparatus that simulates atmospheric effects of human respiration by introducing controlled amounts of carbon dioxide, water vapor, and heat into the air. Denoted a human metabolic simulator (HMS), the apparatus is used for testing life-support equipment when human test subjects are not available. The prior version of the HMS, to be replaced, was designed to simulate the respiratory effects of as many as four persons. It exploits the catalytic combustion of methyl acetate, for which the respiratory quotient (the molar ratio of carbon dioxide produced to oxygen consumed) is very close to the human respiratory quotient of about 0.86. The design of the improved HMS provides for simulation of the respiratory effects of as many as eight persons at various levels of activity. The design would also increase safety by eliminating the use of combustion. The improved HMS (see figure) would include a computer that would exert overall control. The computer would calculate the required amounts of oxygen removal, carbon dioxide addition, water addition, and heat addition by use of empirical equations for metabolic profiles of respiration and heat. A blower would circulate air between the HMS and a chamber containing a life-support system to be tested. With the help of feedback from a mass flowmeter, the blower speed would be adjusted to regulate the rate of flow according to the number of persons to be simulated and to a temperature-regulation requirement (the air temperature would indirectly depend on the rate of flow, among other parameters). Oxygen would be removed from the circulating air by means of a commercially available molecular sieve configured as an oxygen concentrator. Oxygen, argon, and trace amounts of nitrogen would pass through a bed in the molecular sieve while carbon dioxide, the majority of nitrogen, and other trace gases would be trapped by the bed and subsequently returned to the chamber. If

  9. Metabolic Syndrome in Nurses

    Directory of Open Access Journals (Sweden)

    María Escasany

    2014-01-01

    Full Text Available Objectives: To estimate the prevalence of metabolic syndrome (MS in female nurses in the Hospital Juan A. Fernandez (HJAF, Buenos Aires, Argentina, and to determine whether work, rest, diet, and health, are predictive of it.Materials and methods: For the first objective, a descriptive, observational and cross-sectional study was conducted, and for the second, a multivariate cross-sectional observational multivariate analysis was made comparing independent samples. A total of 192 nurses were studied between October 2008 and March 2009. They completed a questionnaire that include indicators that could be predictors of MS. Anthropometric measurements, including blood pressure were taken, was well as a blood sample to analyze fasting glucose, HDL-C and plasma triglycerides.Results: It was found that 35% and 41% of nurses were overweight and obese, respectively. A total of 92% had centro-abdominal obesity. The prevalence of MS found was 33.3% (95%CI, 26.7 to 40.5. Those who had this disease were between 53±9 years. Statistically significant differences were found in the bivariate analysis between MS and the variables, age, length of service, time worked during night shift, and academic studies.Conclusions: The prevalence of MS was 64/192 in HJAF nurses (33.3% I 95%CI, 26.7-40.5. There were no statistically significant differences with the indicators of, age, “time worked during night shift”, and “studies”. These results suggest that age is the most important variable in predicting the onset of MS in the population of nurses.

  10. Serum uric acid levels and metabolic syndrome.

    Science.gov (United States)

    Ciarla, Sara; Struglia, Manuela; Giorgini, Paolo; Striuli, Rinaldo; Necozione, Stefano; Properzi, Giuliana; Ferri, Claudio

    2014-07-01

    To investigate the relationship among serum uric acid levels and metabolic syndrome. Anthropometric parameters, serum uric acid and metabolic parameters were evaluated in 139 subjects. Serum uric acid levels were significantly higher in subjects with than without metabolic syndrome (p metabolic syndrome components (p for trend uric acid significantly correlated with various anthropometric and serum metabolic parameters. Serum uric acid levels were higher in individuals with rather than without metabolic syndrome and raised gradually as the number of metabolic syndrome components increased. The relationship between serum uric acid levels and various metabolic parameters suggests that uric acid might be considered as a component of metabolic syndrome. Hyperuricemia is a common finding in patients with the metabolic syndrome. Recent studies indicated that hyperuricemia may be also a predictor of metabolic syndrome development.

  11. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    Human Drug Metabolism, An Introduction, Second Edition provides an accessible introduction to the subject and will be particularly invaluable to those who already have some understanding of the life sciences...

  12. Identification of Metabolic Pathway Systems

    National Research Council Canada - National Science Library

    Dolatshahi, Sepideh; Voit, Eberhard O

    2016-01-01

    .... Under ideal conditions, the first phase of DFE yields numerical representations of all fluxes within a metabolic pathway system, either as values at each time point or as plots against their substrates and modulators...

  13. Context-dependent metabolic networks

    CERN Document Server

    Beguerisse-Díaz, Mariano; Oyarzún, Diego; Picó, Jesús; Barahona, Mauricio

    2016-01-01

    Cells adapt their metabolism to survive changes in their environment. We present a framework for the construction and analysis of metabolic reaction networks that can be tailored to reflect different environmental conditions. Using context-dependent flux distributions from Flux Balance Analysis (FBA), we produce directed networks with weighted links representing the amount of metabolite flowing from a source reaction to a target reaction per unit time. Such networks are analyzed with tools from network theory to reveal salient features of metabolite flows in each biological context. We illustrate our approach with the directed network of the central carbon metabolism of Escherichia coli, and study its properties in four relevant biological scenarios. Our results show that both flow and network structure depend drastically on the environment: networks produced from the same metabolic model in different contexts have different edges, components, and flow communities, capturing the biological re-routing of metab...

  14. Metabolic-hydaulic model Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The data contained in this workbook were compiled to investigate the relationship between hydrology of the Colorado River and ecosystem metabolism parameters (i.e.,...

  15. Metabolic Acidosis: Diagnostics and Treatment

    Directory of Open Access Journals (Sweden)

    R. F. Tepaev

    2016-01-01

    Full Text Available Metabolic acidosis is the most common child acid-base balance disorder. This condition accompanies a variety of diseases, and the degree of its severity correlates with the patients’ survival: although not a separate disease in itself, metabolic acidosis, however, can worsen the disease course and even lead to death. The pathology causes are various (in connection with life-threatening changes in various organs and systems — lungs, heart and blood vessels, kidneys, and also due to a violation of lipid metabolism, in case of diabetes, poisoning, etc., which determines the fact that a wide range of specialists are interested in the issue. Approaches to the diagnosis simplify the search for the etiology of metabolic acidosis. This study presents data on the physiological basis of acid-base balance regulation, and its etiology and pathophysiology; the principles of therapy are observed.

  16. Macrophages, immunity, and metabolic disease

    National Research Council Canada - National Science Library

    McNelis, Joanne C; Olefsky, Jerrold M

    2014-01-01

    .... It is well recognized that the immune system and metabolism are highly integrated, and macrophages, in particular, have been identified as critical effector cells in the initiation of inflammation...

  17. Metabolic pancreatitis: Etiopathogenesis and management

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Kota

    2013-01-01

    Full Text Available Acute pancreatitis is a medical emergency. Alcohol and gallstones are the most common etiologies accounting for 60%-75% cases. Other important causes include postendoscopic retrograde cholangiopancreatography procedure, abdominal trauma, drug toxicity, various infections, autoimmune, ischemia, and hereditary causes. In about 15% of cases the cause remains unknown (idiopathic pancreatitis. Metabolic conditions giving rise to pancreatitis are less common, accounting for 5%-10% cases. The causes include hypertriglyceridemia, hypercalcemia, diabetes mellitus, porphyria, and Wilson′s disease. The episodes of pancreatitis tend to be more severe. In cases of metabolic pancreatitis, over and above the standard routine management of pancreatitis, careful management of the underlying metabolic abnormalities is of paramount importance. If not treated properly, it leads to recurrent life-threatening bouts of acute pancreatitis. We hereby review the pathogenesis and management of various causes of metabolic pancreatitis.

  18. Metabolic Resistance in Bed Bugs

    Directory of Open Access Journals (Sweden)

    Omprakash Mittapalli

    2011-03-01

    Full Text Available Blood-feeding insects have evolved resistance to various insecticides (organochlorines, pyrethroids, carbamates, etc. through gene mutations and increased metabolism. Bed bugs (Cimex lectularius are hematophagous ectoparasites that are poised to become one of the major pests in households throughout the United States. Currently, C. lectularius has attained a high global impact status due to its sudden and rampant resurgence. Resistance to pesticides is one factor implicated in this phenomenon. Although much emphasis has been placed on target sensitivity, little to no knowledge is available on the role of key metabolic players (e.g., cytochrome P450s and glutathione S-transferases towards pesticide resistance in C. lectularius. In this review, we discuss different modes of resistance (target sensitivity, penetration resistance, behavioral resistance, and metabolic resistance with more emphasis on metabolic resistance.

  19. Metabolic syndrome and periodontal disease

    Directory of Open Access Journals (Sweden)

    Bharti Vipin

    2009-01-01

    Full Text Available It is important for a dentist to be well informed and updated on the latest research on the association of oral and systemic health. Of late, the metabolic syndrome has gained importance in dental literature, and metabolic syndrome and periodontal disease have been linked. Metabolic syndrome (MeS is a group of three or more (up to five interrelated metabolic abnormalities, which increases the risk of cardiovascular morbidity and mortality. Also, both MeS and periodontal disease may be linked through a common pathophysiological pathway. Some studies have been conducted to show such an association and additional studies are required to establish this association. A dental surgeon can play a major role in evaluating patients with MeS and thus prevent the development of overt cardiovascular disease.

  20. Histone variants and lipid metabolism

    NARCIS (Netherlands)

    Borghesan, Michela; Mazzoccoli, Gianluigi; Sheedfar, Fareeba; Oben, Jude; Pazienza, Valerio; Vinciguerra, Manlio

    2014-01-01

    Within nucleosomes, canonical histones package the genome, but they can be opportunely replaced with histone variants. The incorporation of histone variants into the nucleosome is a chief cellular strategy to regulate transcription and cellular metabolism. In pathological terms, cellular steatosis

  1. Complex systems in metabolic engineering.

    Science.gov (United States)

    Winkler, James D; Erickson, Keesha; Choudhury, Alaksh; Halweg-Edwards, Andrea L; Gill, Ryan T

    2015-12-01

    Metabolic engineers manipulate intricate biological networks to build efficient biological machines. The inherent complexity of this task, derived from the extensive and often unknown interconnectivity between and within these networks, often prevents researchers from achieving desired performance. Other fields have developed methods to tackle the issue of complexity for their unique subset of engineering problems, but to date, there has not been extensive and comprehensive examination of how metabolic engineers use existing tools to ameliorate this effect on their own research projects. In this review, we examine how complexity affects engineering at the protein, pathway, and genome levels within an organism, and the tools for handling these issues to achieve high-performing strain designs. Quantitative complexity metrics and their applications to metabolic engineering versus traditional engineering fields are also discussed. We conclude by predicting how metabolic engineering practices may advance in light of an explicit consideration of design complexity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Microelements and inherited metabolic diseases.

    Science.gov (United States)

    Marklová, Eliska

    2002-01-01

    In addition to the main groups of inherited metabolic diseases, including mitochondrial, peroxisomal and lysosomal defects, organic acidurias, porphyrias, defects of amino acids, saccharides and fatty acids metabolism, disorders of transport and utilisation of microelements have also been recognized. Recent findings concerning hereditary hemochromatosis (iron), Wilson and Menkes diseases (copper), molybdenum cofactor deficiency (molybdenum), defects of cobalamine synthesis (cobalt) and acrodermatitis enteropathica (zinc) are reviewed.

  3. Dietary Fats and Metabolic Syndrome

    OpenAIRE

    Danijela Ristic-Medic

    2013-01-01

    The quantity and quality of fats consumed in the diet can have important effects on prevention and/or improvement clustering metabolic abnormalities of the metabolic syndrome. Fatty acids as food ingredients regulate cholesterol homeostasis and concentrations of blood lipoproteins, and affect the levels of other cardiometabolic risk factors, such as blood pressure, haemostasis, and body weight, through various mechanisms. There is convincing evidence that exchanging dietary saturated fat with...

  4. Metabolic studies in thyroid disease

    OpenAIRE

    McCulloch, Alan Jackson

    1983-01-01

    The effects of thyroid hormones on intermediary metabolism have been investigated in hyperthyroid and hypothyroid man and in experimentally induced thyroid disease in the rat. Glucose metabolism was investigated by measurement of blood glucose, fasting and in 3 14 response to meals and by using both H-3-glucose and C-l-glucose as tracers in kinetic studies. Analysis of glycerol clearance from blood following bulk infusions of glycerol permitted evaluation of gluconeoge...

  5. Metabolic syndrome and cardiovascular risk

    Directory of Open Access Journals (Sweden)

    Abdullah M Alshehri

    2010-11-01

    Full Text Available The constellation of dyslipidemia (hypertriglyceridemia and low levels of high-density lipoprotein cholesterol, elevated blood pressure, impaired glucose tolerance, and central obesity is now classified as metabolic syndrome, also called syndrome X. In the past few years, several expert groups have attempted to set forth simple diagnostic criteria for use in clinical practice to identify patients who manifest the multiple components of the metabolic syndrome. These criteria have varied somewhat in specific elements, but in general, they include a combination of multiple and metabolic risk factors. The most widely recognized of the metabolic risk factors are atherogenic dyslipidemia, elevated blood pressure, and elevated plasma glucose. Individuals with these characteristics, commonly manifest a prothrombotic state as well as and a proinflammatory state. Atherogenic dyslipidemia consists of an aggregation of lipoprotein abnormalities including elevated serum triglyceride and apolipoprotein B (apoB, increased small LDL particles, and a reduced level of HDL cholesterol (HDL-C. The metabolic syndrome is often referred to as if it were a discrete entity with a single cause. Available data suggest that it truly is a syndrome, ie, a grouping of atherosclerotic cardiovascular disease (ASCVD risk factors, that probably has more than one cause. Regardless of cause, the syndrome identifies individuals at an elevated risk for ASCVD. The magnitude of the increased risk can vary according to the components of the syndrome present as well as the other, non-metabolic syndrome risk factors in a particular person.

  6. Metabolic surgery and nutritional deficiencies.

    Science.gov (United States)

    Stroh, Christine; Manger, Thomas; Benedix, Frank

    2017-10-01

    The increasing prevalence of morbid obesity in Germany is associated with an increasing number of metabolic surgical interventions. Short-term surgical and long-term metabolic complications such as nutrient deficiencies can be considered as the main risks of metabolic surgery with its malabsorptive but also restrictive procedures. The aim of this review was to characterize the most relevant metabolic complications specific for the various bariatric procedures, which, subsequently, require a permanent surveillance and supplementation, respectively. Furthermore, we aimed to identify if there are diagnostic and therapeutic measures that can prevent those complications. Restrictive bariatric surgery such as "gastric banding" and "sleeve gastrectomy" can be associated with deficiencies related to B-vitamins whereas iron, folate, vitamin B1, B12 and D deficiencies are associated with the malabsorptive procedure such as "biliopancreatic diversion," "duodenal switch" and "Roux-en-Y gastric bypass". Due to possible metabolic and surgical complications after bariatric surgery, patients need to undergo life-long medical and dietetic surveillance. The recently published guidelines of the "American Association of Bariatric and Metabolic Surgery" are the basis for recommendations on supplementation and treatment following weight loss surgery.

  7. Sleep apnoea and metabolic dysfunction

    Directory of Open Access Journals (Sweden)

    Maria R. Bonsignore

    2013-09-01

    Full Text Available Obstructive sleep apnoea (OSA is a highly prevalent condition often associated with central obesity. In the past few years, several studies have analysed the potential independent contribution of OSA to the pathogenesis of metabolic abnormalities, including type 2 diabetes, the metabolic syndrome and non-alcoholic fatty liver disease. New perspectives in OSA patient care have been opened by the promotion of lifestyle interventions, such as diet and exercise programmes that could improve both OSA and the metabolic profile. The rich clinical literature on this subject, together with the growing amount of data on pathophysiological mechanisms provided by animal studies using the chronic intermittent hypoxia model, urged the organising Committee of the Sleep and Breathing meeting to organise a session on sleep apnoea and metabolic dysfunction, in collaboration with the European Association for the Study of Diabetes. This review summarises the state-of-the-art lectures presented in the session, more specifically the relationship between OSA and diabetes, the role of OSA in the metabolic consequences of obesity, and the effects of lifestyle interventions on nocturnal respiratory disturbances and the metabolic profile in OSA patients.

  8. Fenofibrate and metabolic syndrome.

    Science.gov (United States)

    Kraja, Aldi T; Province, Michael A; Straka, Robert J; Ordovas, Jose M; Borecki, Ingrid B; Arnett, Donna K

    2010-06-01

    The fibric acid derivative, fenofibrate (FF) has been used in the US since 1998 to manage patients with dyslipidemia. Typical changes in serum lipids as result a of FF treatment include clinically important mean reductions of serum triglycerides (TG) by a mean change of -93.7 mg/dL (-39.3%), increases of high density lipoprotein cholesterol (HDLC) by +5.5 mg/dL (+12.4%), and reductions in low density lipoprotein cholesterol (LDLC) by -17.9 mg/dL (-12.3%). The greatest reductions in serum TG are usually observed in subjects with elevated baseline TGs including those with the metabolic syndrome (MetS). Although statins remain the mainstay of therapy for most dyslipidemic patients, their combined use with FF would be expected to address residual risk resulting from less than optimal TG and HDLC levels in such patients. Clinical trials examining the cardiovascular benefits of FF alone or combined with statins have produced mixed results. These observations underscore our lack of understanding of which patients may benefit from FF therapy and which do not. Although FF's basic mechanism of action is known to involve PPAR-alpha agonist activity resulting in altered transcription of several genes, the actual genetic bases for variability in lipid response is poorly understood. Studies, such as our GOLDN study and others designed to better understand the genetic determinants of variability in the response to FF treatment and lipid levels. As a result several important genetic determinants of lipid levels have been identified. For example, in the GOLDN study SNPs from different genes were significantly associated with baseline lipid levels before treatment (APOA5- rs662799, rs3135506; APOC3- rs5128, rs2854117, rs4520); APOA4- rs5104; PPARA- rs9626730, rs135543, rs11703495; LPL- rs1801177), after treatment PPARA- rs11708495; LPL- rs1801177, and appeared to modulate overall response to FF treatment (NOS3- rs1799983). In this article, we will review the literature leading up to

  9. Investigation of the microbial diversity of an extremely acidic, metal-rich water body (Lake Robule, Bor, Serbia

    Directory of Open Access Journals (Sweden)

    Stanković Srđan

    2014-01-01

    Full Text Available An investigation of the microbial diversity of the extremely acidic, metal-rich Lake Robule was carried out using culture-dependant and culture-independent (T-RFLP methods, and the ability of indigenous bacteria from the lake water to leach copper from a mineral concentrate was tested. T-RFLP analysis revealed that the dominant bacteria in lake water samples were the obligate heterotroph Acidiphilium cryptum (~50% of total bacteria and the iron-oxidizing autotroph Leptospirillum ferrooxidans (~40% The iron/sulfur-oxidizing autotroph Acidithiobacillus ferrooxidans had been reported to be the most abundant bacteria in the lake in an earlier study by other authors, but it was not detected in the present study using T-RFLP. Although it was isolated on solid media and detected in enrichment (bioleaching cultures. The presence of the two bacterial species detected by T-RFLP (L. ferrooxidans and A. cryptum was also confirmed by cultivation on solid media. The presence and relative abundance of bacteria inhabiting Lake Robule was explained by the physiological characteristics of the bacteria and the physico-chemical characteristics of the lake water. [Projekat Ministarstva nauke Republike Srbije, br. 176016 i br.173048

  10. Dewatering of saline sewage sludge using iron-oxidizing bacteria: Effect of substrate concentration.

    Science.gov (United States)

    Wong, Jonathan W C; Murugesan, Kumarasamy; Selvam, Ammaiyappan; Ravindran, Balasubramanian; Kurade, Mayur B; Yu, Shuk-Man

    2016-08-01

    This study investigated the improvement in dewaterability of activated sludge (ACS) and anaerobically digested sludge (ADS) through bioacidification approach using iron-oxidizing bacterium, Acidithiobacillus ferrooxidans. ACS and ADS were treated with A. ferrooxidans culture with addition of different concentrations of energy substrate, in terms of Fe(2+):sludge solids ratio (0:1, 0.01:1, 0.05:1 and 0.1:1), and the dewaterability was assessed by determining the capillary suction time (CST), time to filter (TTF) and specific resistance to filtration (SRF) of the sludge. The results revealed that the levels of Fe(2+) significantly influenced the sludge acidification (pH⩽3). The CST, TTF and SRF values rapidly decreased in treated sludge, indicating that dewaterability of the sludge was significantly (p<0.05) improved than untreated sludge. This investigation clearly demonstrates that A. ferrooxidans culture, as biogenic flocculant, can be potentially used for improving the sludge flocculation, stabilization and dewaterability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Iron Kinetics and Evolution of Microbial Populations in Low-pH, Ferrous Iron-Oxidizing Bioreactors.

    Science.gov (United States)

    Jones, Rose M; Johnson, D Barrie

    2016-08-02

    Iron-rich, acidic wastewaters are commonplace pollutants associated with metal and coal mining. Continuous-flow bioreactors were commissioned and tested for their capacities to oxidize ferrous iron in synthetic and actual acid mine drainage waters using (initially) pure cultures of the recently described acidophilic, iron-oxidizing heterotrophic bacterium Acidithrix ferrooxidans grown in the presence of glucose and yeast extract. The bioreactors became rapidly colonized by this bacterium, which formed macroscopic streamer growths in the flowing waters. Over 97% of ferrous iron in pH 2.0-2.2 synthetic mine water was oxidized (at up to 225 mg L(-1) h(-1)) at dilution rates (D) of 0.6 h(-1). Rates of iron oxidation decreased with pH but were still significant, with influent liquors as low as pH 1.37. When fed with actual mine water, >90% of ferrous iron was oxidized at D values of 0.4 h(-1), and microbial communities within the bioreactors changed over time, with Atx. ferrooxidans becoming increasingly displaced by the autotrophic iron-oxidizing acidophiles Ferrovum myxofaciens, Acidithiobacillus ferrivorans, and Leptospirillum ferrooxidans (which were all indigenous to the mine water), although this did not have a negative impact on net ferrous-iron oxidation. The results confirmed the potential of using a heterotrophic acidophile to facilitate the rapid commissioning of iron-oxidizing bioreactors and illustrated how microbial communities within them can evolve without compromising the performances of the bioreactors.

  12. Symptoms and Diagnosis of Metabolic Syndrome

    Science.gov (United States)

    ... Thromboembolism Aortic Aneurysm More Symptoms and Diagnosis of Metabolic Syndrome Updated:Apr 13,2017 What are the symptoms ... Syndrome? This content was last reviewed August 2016. Metabolic Syndrome • Home • About Metabolic Syndrome • Why Metabolic Syndrome Matters • ...

  13. Inferring ancient metabolism using ancestral core metabolic models of enterobacteria.

    Science.gov (United States)

    Baumler, David J; Ma, Bing; Reed, Jennifer L; Perna, Nicole T

    2013-06-11

    Enterobacteriaceae diversified from an ancestral lineage ~300-500 million years ago (mya) into a wide variety of free-living and host-associated lifestyles. Nutrient availability varies across niches, and evolution of metabolic networks likely played a key role in adaptation. Here we use a paleo systems biology approach to reconstruct and model metabolic networks of ancestral nodes of the enterobacteria phylogeny to investigate metabolism of ancient microorganisms and evolution of the networks. Specifically, we identified orthologous genes across genomes of 72 free-living enterobacteria (16 genera), and constructed core metabolic networks capturing conserved components for ancestral lineages leading to E. coli/Shigella (~10 mya), E. coli/Shigella/Salmonella (~100 mya), and all enterobacteria (~300-500 mya). Using these models we analyzed the capacity for carbon, nitrogen, phosphorous, sulfur, and iron utilization in aerobic and anaerobic conditions, identified conserved and differentiating catabolic phenotypes, and validated predictions by comparison to experimental data from extant organisms. This is a novel approach using quantitative ancestral models to study metabolic network evolution and may be useful for identification of new targets to control infectious diseases caused by enterobacteria.

  14. Analysis of metabolic flux using dynamic labelling and metabolic modelling.

    Science.gov (United States)

    Fernie, A R; Morgan, J A

    2013-09-01

    Metabolic fluxes and the capacity to modulate them are a crucial component of the ability of the plant cell to react to environmental perturbations. Our ability to quantify them and to attain information concerning the regulatory mechanisms that control them is therefore essential to understand and influence metabolic networks. For all but the simplest of flux measurements labelling methods have proven to be the most informative. Both steady-state and dynamic labelling approaches have been adopted in the study of plant metabolism. Here the conceptual basis of these complementary approaches, as well as their historical application in microbial, mammalian and plant sciences, is reviewed, and an update on technical developments in label distribution analyses is provided. This is supported by illustrative cases studies involving the kinetic modelling of secondary metabolism. One issue that is particularly complex in the analysis of plant fluxes is the extensive compartmentation of the plant cell. This problem is discussed from both theoretical and experimental perspectives, and the current approaches used to address it are assessed. Finally, current limitations and future perspectives of kinetic modelling of plant metabolism are discussed. © 2013 John Wiley & Sons Ltd.

  15. Analog regulation of metabolic demand

    Directory of Open Access Journals (Sweden)

    Muskhelishvili Georgi

    2011-03-01

    Full Text Available Abstract Background The 3D structure of the chromosome of the model organism Escherichia coli is one key component of its gene regulatory machinery. This type of regulation mediated by topological transitions of the chromosomal DNA can be thought of as an analog control, complementing the digital control, i.e. the network of regulation mediated by dedicated transcription factors. It is known that alterations in the superhelical density of chromosomal DNA lead to a rich pattern of differential expressed genes. Using a network approach, we analyze these expression changes for wild type E. coli and mutants lacking nucleoid associated proteins (NAPs from a metabolic and transcriptional regulatory network perspective. Results We find a significantly higher correspondence between gene expression and metabolism for the wild type expression changes compared to mutants in NAPs, indicating that supercoiling induces meaningful metabolic adjustments. As soon as the underlying regulatory machinery is impeded (as for the NAP mutants, this coherence between expression changes and the metabolic network is substantially reduced. This effect is even more pronounced, when we compute a wild type metabolic flux distribution using flux balance analysis and restrict our analysis to active reactions. Furthermore, we are able to show that the regulatory control exhibited by DNA supercoiling is not mediated by the transcriptional regulatory network (TRN, as the consistency of the expression changes with the TRN logic of activation and suppression is strongly reduced in the wild type in comparison to the mutants. Conclusions So far, the rich patterns of gene expression changes induced by alterations of the superhelical density of chromosomal DNA have been difficult to interpret. Here we characterize the effective networks formed by supercoiling-induced gene expression changes mapped onto reconstructions of E. coli's metabolic and transcriptional regulatory network. Our

  16. Genome scale metabolic modeling of cancer

    DEFF Research Database (Denmark)

    Nilsson, Avlant; Nielsen, Jens

    2017-01-01

    Cancer cells reprogram metabolism to support rapid proliferation and survival. Energy metabolism is particularly important for growth and genes encoding enzymes involved in energy metabolism are frequently altered in cancer cells. A genome scale metabolic model (GEM) is a mathematical formalization...... of metabolism which allows simulation and hypotheses testing of metabolic strategies. It has successfully been applied to many microorganisms and is now used to study cancer metabolism. Generic models of human metabolism have been reconstructed based on the existence of metabolic genes in the human genome....... Cancer specific models of metabolism have also been generated by reducing the number of reactions in the generic model based on high throughput expression data, e.g. transcriptomics and proteomics. Targets for drugs and bio markers for diagnostics have been identified using these models. They have also...

  17. [Lead compound optimization strategy (1)--changing metabolic pathways and optimizing metabolism stability].

    Science.gov (United States)

    Wang, Jiang; Liu, Hong

    2013-10-01

    Lead compound optimization plays an important role in new drug discovery and development. The strategies for changing metabolic pathways can modulate pharmacokinetic properties, prolong the half life, improve metabolism stability and bioavailability of lead compounds. The strategies for changing metabolic pathways and improving metabolism stability are reviewed. These methods include blocking metabolic site, reduing lipophilicity, changing ring size, bioisosterism, and prodrug.

  18. Response to trauma and metabolic changes: posttraumatic metabolism.

    Science.gov (United States)

    Şimşek, Turgay; Şimşek, Hayal Uzelli; Cantürk, Nuh Zafer

    2014-01-01

    Stress response caused by events such as surgical trauma includes endocrine, metabolic and immunological changes. Stress hormones and cytokines play a role in these reactions. More reactions are induced by greater stress, ultimately leading to greater catabolic effects. Cuthbertson reported the characteristic response that occurs in trauma patients: protein and fat consumption and protection of body fluids and electrolytes because of hypermetabolism in the early period. The oxygen and energy requirement increases in proportion to the severity of trauma. The awareness of alterations in amino acid, lipid, and carbohydrate metabolism changes in surgical patients is important in determining metabolic and nutritional support. The main metabolic change in response to injury that leads to a series of reactions is the reduction of the normal anabolic effect of insulin, i.e. the development of insulin resistance. Free fatty acids are primary sources of energy after trauma. Triglycerides meet 50 to 80 % of the consumed energy after trauma and in critical illness. Surgical stress and trauma result in a reduction in protein synthesis and moderate protein degradation. Severe trauma, burns and sepsis result in increased protein degradation. The aim of glucose administration to surgical patients during fasting is to reduce proteolysis and to prevent loss of muscle mass. In major stress such as sepsis and trauma, it is important both to reduce the catabolic response that is the key to faster healing after surgery and to obtain a balanced metabolism in the shortest possible time with minimum loss. For these reasons, the details of metabolic response to trauma should be known in managing these situations and patients should be treated accordingly.

  19. Metabolic triggered inflammation in osteoarthritis.

    Science.gov (United States)

    Wang, X; Hunter, D; Xu, J; Ding, C

    2015-01-01

    Osteoarthritis (OA) is a common chronic joint disorder with a multifactorial etiology including genetic and environmental factors. Metabolic triggered inflammation, induced by nutrient overload and metabolic surplus, consists of components such as obesity, pro-inflammatory cytokines and adipokines, abnormal metabolites, acute phase proteins, vitamin D deficiency, and deregulated microRNAs that may play a role in OA pathophysiology. Obesity-related metabolic factors, especially adipokines, contribute to OA development by inducing pro-inflammatory cytokines and degradative enzymes, leading to cartilage matrix impairment and subchondral bone remodeling. Ectopic metabolite deposition and low-grade systemic inflammation can contribute to a toxic internal environment that exacerbates OA. Complement components highly expressed in osteoarthritic joints have also been proposed as causative factors. Vitamin D deficiency has been associated with obesity and is implicated to be associated with cartilage loss in OA. Metabolic microRNAs may explain the inflammatory link between obesity and OA. Therapies targeting metabolic-triggered inflammation and its components are anticipated to have potential for the treatment of OA. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  20. Metabolic Cost of Experimental Exercises

    Science.gov (United States)

    Webb, James T.; Gernhardt, Michael L.

    2009-01-01

    Although the type and duration of activity during decompression was well documented, the metabolic cost of 1665 subject-exposures with 8 activity profiles from 17 altitude decompression sickness (DCS) protocols at Brooks City-Base, TX from 1983-2005 was not determined. Female and male human volunteers (30 planned, 4 completed) performed activity profiles matching those 8 activity profiles at ground level with continuous monitoring of metabolic cost. A Cosmed K4b2 Cardio Pulmonary Exercise Testing device was used to measure oxygen uptake (VO2) during the profiles. The results show levels of metabolic cost to the females for the profiles tested varied from 4.3 to 25.5 ml/kg/min and from 3.0 to 12.0 ml/kg/min to the males. The increase in VO2 from seated rest to the most strenuous of the 8 activity profiles was 3.6-fold for the females and 2.8-fold for the males. These preliminary data on 4 subjects indicate close agreement of oxygen uptake for activity performed during many subject-exposures as published earlier. The relatively low average oxygen uptake required to perform the most strenuous activity may imply the need for adjustment of modeling efforts using metabolic cost as a risk factor. Better definition of metabolic cost during exposure to altitude, a critical factor in DCS risk, may allow refinement of DCS prediction models.

  1. Metabolic acceleration in Mediterranean Perciformes

    Science.gov (United States)

    Lika, Konstadia; Kooijman, Sebastiaan A. L. M.; Papandroulakis, Nikos

    2014-11-01

    Larval stages are considered the most critical of fish development. During a very short period of time (2 to 3 months), larvae undergo major morphoanatomical and functional changes in order to transform into juveniles while remaining functioning (developing, eating, surviving). Depending on species and environmental conditions, patterns in larval development may vary. We study the patterns of larval development for nine fish species of Perciformes reared under aquaculture conditions and compare them in terms of species-specific parameters derived from DEB theory. We extended the standard DEB model to include metabolic acceleration during the larval period, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis. Metabolic acceleration has as a consequence that larvae initially grow slower than juveniles and adults. Our results indicate that the species with higher acceleration have lower growth rates at birth and they also suggest that metabolic acceleration is related to spawning season. High metabolic acceleration of demersal species is associated with summer-autumn spawning in the Mediterranean, where temperature is high and food availability is low.

  2. Thermodynamic Constraints Improve Metabolic Networks.

    Science.gov (United States)

    Krumholz, Elias W; Libourel, Igor G L

    2017-08-08

    In pursuit of establishing a realistic metabolic phenotypic space, the reversibility of reactions is thermodynamically constrained in modern metabolic networks. The reversibility constraints follow from heuristic thermodynamic poise approximations that take anticipated cellular metabolite concentration ranges into account. Because constraints reduce the feasible space, draft metabolic network reconstructions may need more extensive reconciliation, and a larger number of genes may become essential. Notwithstanding ubiquitous application, the effect of reversibility constraints on the predictive capabilities of metabolic networks has not been investigated in detail. Instead, work has focused on the implementation and validation of the thermodynamic poise calculation itself. With the advance of fast linear programming-based network reconciliation, the effects of reversibility constraints on network reconciliation and gene essentiality predictions have become feasible and are the subject of this study. Networks with thermodynamically informed reversibility constraints outperformed gene essentiality predictions compared to networks that were constrained with randomly shuffled constraints. Unconstrained networks predicted gene essentiality as accurately as thermodynamically constrained networks, but predicted substantially fewer essential genes. Networks that were reconciled with sequence similarity data and strongly enforced reversibility constraints outperformed all other networks. We conclude that metabolic network analysis confirmed the validity of the thermodynamic constraints, and that thermodynamic poise information is actionable during network reconciliation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Transgenerational inheritance of metabolic disease.

    Science.gov (United States)

    Stegemann, Rachel; Buchner, David A

    2015-07-01

    Metabolic disease encompasses several disorders including obesity, type 2 diabetes, and dyslipidemia. Recently, the incidence of metabolic disease has drastically increased, driven primarily by a worldwide obesity epidemic. Transgenerational inheritance remains controversial, but has been proposed to contribute to human metabolic disease risk based on a growing number of proof-of-principle studies in model organisms ranging from Caenorhabditis elegans to Mus musculus to Sus scrofa. Collectively, these studies demonstrate that heritable risk is epigenetically transmitted from parent to offspring over multiple generations in the absence of a continued exposure to the triggering stimuli. A diverse assortment of initial triggers can induce transgenerational inheritance including high-fat or high-sugar diets, low-protein diets, various toxins, and ancestral genetic variants. Although the mechanistic basis underlying the transgenerational inheritance of disease risk remains largely unknown, putative molecules mediating transmission include small RNAs, histone modifications, and DNA methylation. Due to the considerable impact of metabolic disease on human health, it is critical to better understand the role of transgenerational inheritance of metabolic disease risk to open new avenues for therapeutic intervention and improve upon the current methods for clinical diagnoses and treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Calcium metabolism & hypercalcemia in adults.

    Science.gov (United States)

    Lumachi, F; Motta, R; Cecchin, D; Ave, S; Camozzi, V; Basso, S M M; Luisetto, G

    2011-01-01

    Calcium is essential for many metabolic process, including nerve function, muscle contraction, and blood clotting. The metabolic pathways that contribute to maintain serum calcium levels are bone remodeling processes, intestinal absorption and secretion, and renal handling, but hypercalcemia occurs when at least 2 of these 3 metabolic pathways are altered. Calcium metabolism mainly depends on the activity of parathyroid hormone (PTH). Its secretion is strictly controlled by the ionized serum calcium levels through a negative feed-back, which is achieved by the activation of calcium-sensing receptors (CaSRs) mainly expressed on the surface of the parathyroid cells. The PTH receptor in bone and kidney is now referred as PTHR1. The balance of PTH, calcitonin, and vitamin D has long been considered the main regulator of calcium metabolism, but the function of other actors, such as fibroblast growth factor-23 (FGF-23), Klotho, and TPRV5 should be considered. Primary hyperparathyroidism and malignancy are the most common causes of hypercalcemia, accounting for more than 90% of cases. Uncontrolled hypercalcemia may cause renal impairment, both temporary (alteration of renal tubular function) and progressive (relapsing nephrolithiasis), leading to a progressive loss of renal function, as well as severe bone diseases, and heart damages. Advances in the understanding of all actors of calcium homeostasis will be crucial, having several practical consequences in the treatment and prevention of hypercalcemia. This would allow to move from a support therapy, sometimes ineffective, to a specific and addressed therapy, especially in patients with chronic hypercalcemic conditions unsuitable for surgery.

  5. Metabolic traits of pathogenic streptococci.

    Science.gov (United States)

    Willenborg, Jörg; Goethe, Ralph

    2016-11-01

    Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction. © 2016 Federation of European Biochemical Societies.

  6. Opioid metabolism and clinical aspects.

    Science.gov (United States)

    Mercadante, Sebastiano

    2015-12-15

    Opioids are are commonly used for the management of acute and chronic pain. Opioids have different physicochemical and pharmacokinetic characteristics, which explain the profound changes in the clinical effect in several clinical conditions. Pharmacokinetics influences the opioid response affecting bioavailability, production of metabolites with residual clinical activity, and elimination. Generality of opioid metabolism and clinical implications for specific opioids in different clinical conditions were reviewed to bridge the gap between pharmacokinetics and clinical response. The knowledge of opioid metabolism is essential, particularly for older and complicated patients who receive multiple medications and may have impaired of renal and hepatic function. The recognition of possible metabolic problems and the consideration of adverse drug-drug interactions are fundamental to optimize the use of opioids in clinical practice. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Novel genes in LDL metabolism

    DEFF Research Database (Denmark)

    Christoffersen, Mette; Tybjærg-Hansen, Anne

    2015-01-01

    PURPOSE OF REVIEW: To summarize recent findings from genome-wide association studies (GWAS), whole-exome sequencing of patients with familial hypercholesterolemia and 'exome chip' studies pointing to novel genes in LDL metabolism. RECENT FINDINGS: The genetic loci for ATP-binding cassette......-exome sequencing and 'exome chip' studies have additionally suggested several novel genes in LDL metabolism including insulin-induced gene 2, signal transducing adaptor family member 1, lysosomal acid lipase A, patatin-like phospholipase domain-containing protein 5 and transmembrane 6 superfamily member 2. Most...... of these findings still require independent replications and/or functional studies to confirm the exact role in LDL metabolism and the clinical implications for human health. SUMMARY: GWAS, exome sequencing studies, and recently 'exome chip' studies have suggested several novel genes with effects on LDL cholesterol...

  8. Enzymes of inorganic polyphosphate metabolism.

    Science.gov (United States)

    Kulakovskaya, Tatyana; Kulaev, Igor

    2013-01-01

    Inorganic polyphosphate (PolyP) is a linear polymer containing a few to several hundred orthophosphate residues linked by energy-rich phosphoanhydride bonds. Investigation of PolyP-metabolizing enzymes is important for medicine, because PolyPs perform numerous functions in the cells. In human organism, PolyPs are involved in the regulation of Ca(2+) uptake in mitochondria, bone tissue development, and blood coagulation. The essentiality of polyphosphate kinases in the virulence of pathogenic bacteria is a basis for the discovery of new antibiotics. The properties of the major enzymes of PolyP metabolism, first of all polyphosphate kinases and exopolyphosphatases, are described in the review. The main differences between the enzymes of PolyP biosynthesis and utilization of prokaryotic and eukaryotic cells, as well as the multiple functions of some enzymes of PolyP metabolism, are considered.

  9. Exercise training in metabolic myopathies

    DEFF Research Database (Denmark)

    Vissing, J

    2016-01-01

    Metabolic myopathies encompass muscle glycogenoses (GSD) and disorders of muscle fat oxidation (FAOD). FAODs and GSDs can be divided into two main clinical phenotypes; those with static symptoms related to fixed muscle weakness and atrophy, and those with dynamic, exercise-related symptoms...... that are brought about by a deficient supply of ATP. Together with mitochondrial myopathies, metabolic myopathies are unique among muscle diseases, as the limitation in exercise performance is not solely caused by structural damage of muscle, but also or exclusively related to energy deficiency. ATP consumption...... can increase 50-100-fold in contracting, healthy muscle from rest to exercise, and testing patients with exercise is therefore an appropriate approach to disclose limitations in work capacity and endurance in metabolic myopathies. Muscles rely almost exclusively on muscle glycogen in the initial...

  10. Fat sensing and metabolic syndrome.

    Science.gov (United States)

    Youn, Jang H

    2014-12-01

    Overconsumption of dietary fat contributes to the development of obesity and metabolic syndrome. Recent evidence suggests that high dietary fat may promote these metabolic states not only by providing calories but also by inducing impaired control of energy balance. In normal metabolic states, fat interacts with various organs or receptors to generate signals for the regulation of energy balance. Many of these interactions are impaired by high-fat diets or in obesity, contributing to the development or maintenance of obesity. These impairments may arise largely from fundamental alterations in the hypothalamus where all peripheral signals are integrated to regulate energy balance. This review focuses on various mechanisms by which fat is sensed at different stages of ingestion, circulation, storage, and utilization to regulate food intake, and how these individual mechanisms are altered by high-fat diets or in obesity.

  11. DNA methylation in metabolic disorders

    DEFF Research Database (Denmark)

    Barres, Romain; Zierath, Juleen R

    2011-01-01

    DNA methylation is a major epigenetic modification that controls gene expression in physiologic and pathologic states. Metabolic diseases such as diabetes and obesity are associated with profound alterations in gene expression that are caused by genetic and environmental factors. Recent reports...... have provided evidence that environmental factors at all ages could modify DNA methylation in somatic tissues, which suggests that DNA methylation is a more dynamic process than previously appreciated. Because of the importance of lifestyle factors in metabolic disorders, DNA methylation provides...... a mechanism by which environmental factors, including diet and exercise, can modify genetic predisposition to disease. This article considers the current evidence that defines a role for DNA methylation in metabolic disorders....

  12. Exercise in the Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Saeid Golbidi

    2012-01-01

    Full Text Available The metabolic syndrome is a clustering of obesity, diabetes, hyperlipidemia, and hypertension that is occurring in increasing frequency across the global population. Although there is some controversy about its diagnostic criteria, oxidative stress, which is defined as imbalance between the production and inactivation of reactive oxygen species, has a major pathophysiological role in all the components of this disease. Oxidative stress and consequent inflammation induce insulin resistance, which likely links the various components of this disease. We briefly review the role of oxidative stress as a major component of the metabolic syndrome and then discuss the impact of exercise on these pathophysiological pathways. Included in this paper is the effect of exercise in reducing fat-induced inflammation, blood pressure, and improving muscular metabolism.

  13. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  14. Principal Metabolic Flux Mode Analysis.

    Science.gov (United States)

    Bhadra, Sahely; Blomberg, Peter; Castillo, Sandra; Rousu, Juho; Wren, Jonathan

    2018-02-06

    In the analysis of metabolism, two distinct and complementary approaches are frequently used: Principal component analysis (PCA) and stoichiometric flux analysis. PCA is able to capture the main modes of variability in a set of experiments and does not make many prior assumptions about the data, but does not inherently take into account the flux mode structure of metabolism. Stoichiometric flux analysis methods, such as Flux Balance Analysis (FBA) and Elementary Mode Analysis, on the other hand, are able to capture the metabolic flux modes, however, they are primarily designed for the analysis of single samples at a time, and not best suited for exploratory analysis on a large sets of samples. We propose a new methodology for the analysis of metabolism, called Principal Metabolic Flux Mode Analysis (PMFA), which marries the PCA and stoichiometric flux analysis approaches in an elegant regularized optimization framework. In short, the method incorporates a variance maximization objective form PCA coupled with a stoichiometric regularizer, which penalizes projections that are far from any flux modes of the network. For interpretability, we also introduce a sparse variant of PMFA that favours flux modes that contain a small number of reactions. Our experiments demonstrate the versatility and capabilities of our methodology. The proposed method can be applied to genome-scale metabolic network in efficient way as PMFA does not enumerate elementary modes. In addition, the method is more robust on out-of-steady steady-state experimental data than competing flux mode analysis approaches. Matlab software for PMFA and SPMFA and data set used for experiments are available in https://github.com/aalto-ics-kepaco/PMFA. sahely@iitpkd.ac.in, juho.rousu@aalto.fi, Peter.Blomberg@vtt.fi, Sandra.Castillo@vtt.fi. Detailed results are in Supplementary files. Supplementary data are available at https://github.com/aalto-ics-kepaco/PMFA/blob/master/Results.zip.

  15. Thyroid Hormone Regulation of Metabolism

    Science.gov (United States)

    Mullur, Rashmi; Liu, Yan-Yun

    2014-01-01

    Thyroid hormone (TH) is required for normal development as well as regulating metabolism in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially expressed in tissues and have distinct roles in TH signaling. Local activation of thyroxine (T4), to the active form, triiodothyronine (T3), by 5′-deiodinase type 2 (D2) is a key mechanism of TH regulation of metabolism. D2 is expressed in the hypothalamus, white fat, brown adipose tissue (BAT), and skeletal muscle and is required for adaptive thermogenesis. The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite. The nutrient status of the cell provides feedback on TH signaling pathways through epigentic modification of histones. Integration of TH signaling with the adrenergic nervous system occurs peripherally, in liver, white fat, and BAT, but also centrally, in the hypothalamus. TR regulates cholesterol and carbohydrate metabolism through direct actions on gene expression as well as cross-talk with other nuclear receptors, including peroxisome proliferator-activated receptor (PPAR), liver X receptor (LXR), and bile acid signaling pathways. TH modulates hepatic insulin sensitivity, especially important for the suppression of hepatic gluconeogenesis. The role of TH in regulating metabolic pathways has led to several new therapeutic targets for metabolic disorders. Understanding the mechanisms and interactions of the various TH signaling pathways in metabolism will improve our likelihood of identifying effective and selective targets. PMID:24692351

  16. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...... phthalates, but our knowledge about metabolic distribution in the body and other biological fluids, including breast milk, is limited. Compared to urine, human breast milk contains relatively more of the hydrophobic phthalates, such as di-n-butyl phthalate and the longer-branched, di(2-ethylhexyl) phthalate...

  17. Metabolic Syndrome and Incident Diabetes

    OpenAIRE

    Ford, Earl S.; Li, Chaoyang; Sattar, Naveed

    2008-01-01

    OBJECTIVE?Our objective was to perform a quantitative review of prospective studies examining the association between the metabolic syndrome and incident diabetes. RESEARCH DESIGN AND METHODS?Using the title terms ?diabetes? and ?metabolic syndrome? in PubMed, we searched for articles published since 1998. RESULTS?Based on the results from 16 cohorts, we performed a meta-analysis of estimates of relative risk (RR) and incident diabetes. The random-effects summary RRs were 5.17 (95% CI 3.99?6....

  18. Metabolic Acidosis and Subclinical Metabolic Acidosis in CKD.

    Science.gov (United States)

    Raphael, Kalani L

    2017-10-13

    Metabolic acidosis is not uncommon in CKD and is linked with bone demineralization, muscle catabolism, and higher risks of CKD progression and mortality. Clinical practice guidelines recommend maintaining serum total CO2 at ≥22 mEq/L to help prevent these complications. Although a definitive trial testing whether correcting metabolic acidosis improves clinical outcomes has not been conducted, results from small, single-center studies support this notion. Furthermore, biologic plausibility supports the notion that a subset of patients with CKD have acid-mediated organ injury despite having a normal serum total CO2 and might benefit from oral alkali before overt acidosis develops. Identifying these individuals with subclinical metabolic acidosis is challenging, but recent results suggest that urinary acid excretion measurements may be helpful. The dose of alkali to provide in this setting is unknown as well. The review discusses these topics and the prevalence and risk factors of metabolic acidosis, mechanisms of acid-mediated organ injury, results from interventional studies, and potential harms of alkali therapy in CKD. Copyright © 2017 by the American Society of Nephrology.

  19. Metabolic imaging of pancreatic ductal adenocarcinoma detects altered choline metabolism.

    Science.gov (United States)

    Penet, Marie-France; Shah, Tariq; Bharti, Santosh; Krishnamachary, Balaji; Artemov, Dmitri; Mironchik, Yelena; Wildes, Flonné; Maitra, Anirban; Bhujwalla, Zaver M

    2015-01-15

    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal disease that develops relatively symptom-free and is therefore advanced at the time of diagnosis. The absence of early symptoms and effective treatments has created a critical need for identifying and developing new noninvasive biomarkers and therapeutic targets. We investigated the metabolism of a panel of PDAC cell lines in culture and noninvasively in vivo with (1)H magnetic resonance spectroscopic imaging (MRSI) to identify noninvasive biomarkers and uncover potential metabolic targets. We observed elevated choline-containing compounds in the PDAC cell lines and tumors. These elevated choline-containing compounds were easily detected by increased total choline (tCho) in vivo, in spectroscopic images obtained from tumors. Principal component analysis of the spectral data identified additional differences in metabolites between immortalized human pancreatic cells and neoplastic PDAC cells. Molecular characterization revealed overexpression of choline kinase (Chk)-α, choline transporter 1 (CHT1), and choline transporter-like protein 1 (CTL1) in the PDAC cell lines and tumors. Collectively, these data identify new metabolic characteristics of PDAC and reveal potential metabolic targets. Total choline detected with (1)H MRSI may provide an intrinsic, imaging probe-independent biomarker to complement existing techniques in detecting PDAC. The expression of Chk-α, CHT1, and CTL1 may provide additional molecular markers in aspirated cytological samples. ©2014 American Association for Cancer Research.

  20. Incidence and Major Metabolic Risk Factors of Metabolic Syndrome ...

    African Journals Online (AJOL)

    The study involved 300 (92 males and 208 females) type 2 diabetic patients and was conducted at the Tamale Teaching/Regional Hospital from June 2006 to May 2007. Metabolic syndrome was diagnosed using the National Cholesterol Education Programme, Adult Treatment Panel III (2001) criteria. The incidence of the ...

  1. Human metabolism and metabolic interactions of deployment-related chemicals.

    Science.gov (United States)

    Hodgson, Ernest; Rose, Randy L

    2005-01-01

    It has been suggested that chemicals and, more specifically, chemical interactions, are involved as causative agents in deployment-related illnesses. Unfortunately, this hypothesis has proven difficult to test, because toxicological investigations of deployment-related chemicals are usually carried out on surrogate animals and are difficult to extrapolate to humans. Other parts of the problem, such as the definition of variation within human populations and the development of methods for designating groups or individuals at significantly greater risk, cannot be carried out on surrogate animals, and the data must be derived from humans. The relatively recent availability of human cell.fractions, such as microsomes, cytosol, etc., human cells such as primary hepatocytes, recombinant human enzymes, and their isoforms and polymorphic variants has enabled a significant start to be made in developing the human data needed. These initial studies have examined the human metabolism by cytochrome P450, other phase I enzymes, and their isoforms and, in some cases, their polymorphic variants of compounds such as chlorpyrifos, carbaryl, DEET, permethrin, and pyridostigmine bromide, and, to a lesser extent, other chemicals from the same chemical and use classes, including solvents, jet fuel components, and sulfur mustard metabolites. A number of interactions at the metabolic level have been described both with respect to other xenobiotics and to endogenous metabolites. Probably the most dramatic have been seen in the ability of chlorpyrifos to inhibit not only the metabolism of other xenobiotics such as carbaryl and DEET but also to inhibit the metabolism of steroid hormones.

  2. IDH1 mutations alter citric acid cycle metabolism and increase dependence on oxidative mitochondrial metabolism

    National Research Council Canada - National Science Library

    Grassian, Alexandra R; Parker, Seth J; Davidson, Shawn M; Divakaruni, Ajit S; Green, Courtney R; Zhang, Xiamei; Slocum, Kelly L; Pu, Minying; Lin, Fallon; Vickers, Chad; Joud-Caldwell, Carol; Chung, Franklin; Yin, Hong; Handly, Erika D; Straub, Christopher; Growney, Joseph D; Vander Heiden, Matthew G; Murphy, Anne N; Pagliarini, Raymond; Metallo, Christian M

    2014-01-01

    .... We observed that under hypoxic conditions, IDH1-mutant cells exhibited increased oxidative tricarboxylic acid metabolism along with decreased reductive glutamine metabolism, but not IDH2-mutant cells...

  3. Metabolic control of the cell cycle.

    Science.gov (United States)

    Kalucka, Joanna; Missiaen, Rindert; Georgiadou, Maria; Schoors, Sandra; Lange, Christian; De Bock, Katrien; Dewerchin, Mieke; Carmeliet, Peter

    2015-01-01

    Cell division is a metabolically demanding process, requiring the production of large amounts of energy and biomass. Not surprisingly therefore, a cell's decision to initiate division is co-determined by its metabolic status and the availability of nutrients. Emerging evidence reveals that metabolism is not only undergoing substantial changes during the cell cycle, but it is becoming equally clear that metabolism regulates cell cycle progression. Here, we overview the emerging role of those metabolic pathways that have been best characterized to change during or influence cell cycle progression. We then studied how Notch signaling, a key angiogenic pathway that inhibits endothelial cell (EC) proliferation, controls EC metabolism (glycolysis) during the cell cycle.

  4. Exercise heat stress and metabolism.

    Science.gov (United States)

    Mündel, Toby

    2008-01-01

    Apart from few studies, the majority of the research conducted on the effects of heat stress on energy metabolism during exercise has only been done so in the past two decades. Whilst increasing exercise duration under conditions of heat stress favours the oxidation of carbohydrate (CHO) and appears to increase the rate of muscle glycogenolysis, total CHO oxidation is often less and levels of muscle glycogen remain much higher at the point of fatigue when compared with the same exercise without heat stress. Furthermore, supplementing CHO during exercise in the heat appears to exert an ergogenic effect that is not related to 'peripheral' but rather 'central' factors. However, there may be a role for the excess ammonia (NH3) produced in the exercising muscle during heat stress, as cerebral uptake and subsequent metabolism of NH3 may have detrimental effects on cerebral function. Recent exciting results point toward an increased cerebral CHO uptake relative to that of O2, termed the cerebral metabolic ratio (CMR) during exercise with heat stress, although a causative link between this and reduced exercise performance has yet to be identified. Therefore, it appears that despite a shift towards greater CHO utilisation in both skeletal muscular and cerebral metabolism, these responses have ultimately not proved limiting to exercise with heat stress.

  5. Absorption and Metabolism of Xanthophylls

    Directory of Open Access Journals (Sweden)

    Eiichi Kotake-Nara

    2011-06-01

    Full Text Available Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  6. Metabolic diversity in apple germplasm

    NARCIS (Netherlands)

    Khan, S.A.; Tikunov, Y.M.; Chibon, P.Y.F.R.P.; Maliepaard, C.A.; Beekwilder, M.J.; Jacobsen, E.; Schouten, H.J.

    2014-01-01

    We analysed metabolic diversity in apples from wild species, elite material and a F1 population, using liquid chromatography–mass spectrometry (LC-QTOF-MS). The evaluated elite material appeared to have strongly reduced levels of phenolic compounds, down to 1% of the concentrations in the

  7. Diurnal variations in myocardial metabolism

    Science.gov (United States)

    The heart is challenged by a plethora of extracellular stimuli over the course of a normal day, each of which distinctly influences myocardial contractile function. It is therefore not surprising that myocardial metabolism also oscillates in a time-of-day dependent manner. What is becoming increasin...

  8. Metabolic Imaging in Parkinson Disease

    NARCIS (Netherlands)

    Meles, Sanne K.; Teune, Laura K.; de Jong, Bauke M.; Dierckx, Rudi A.; Leenders, Klaus L.

    This review focuses on recent human 18F-FDG PET studies in Parkinson disease. First, an overview is given of the current analytic approaches to metabolic brain imaging data. Next, we discuss how 18F-FDG PET studies have advanced understanding of the relation between distinct brain regions and

  9. Metabolic fate of hallucinogenic NBOMes

    DEFF Research Database (Denmark)

    Leth-Petersen, Sebastian; Gabel-Jensen, Charlotte; Gillings, Nic

    2016-01-01

    as a PET-ligand for clinical investigations of the 5HT2AR ([11C]Cimbi-36). Herein, we have identified the phase I and phase II metabolites of 25B-NBOMe in pigs as well as in humans. We find that the primary route of metabolism is 5'-demethylation, followed by conjugation to glucuronic acid. [11C...

  10. Estrogen Metabolism and Breast Cancer

    African Journals Online (AJOL)

    pathway mediated by the generation and redox Cycling of reactive oxygen species through the metabolic effects of estrogen .... therapy. Several studies including the European. Organization for Research and Treatment of. Cancer ÇEORTC) trial,19 the ATAC (Arimidex, tamoxifen, alone or in combination) adjuvant breast.

  11. Alcohol abuse and glycoconjugate metabolism

    Directory of Open Access Journals (Sweden)

    Sylwia Chojnowska

    2012-04-01

    Full Text Available The relationship between alcohol consumption and glycoconjugate metabolism is complex and multidimensional. This review summarizes the advances in basic and clinical research on the molecular and cellular events involved in the metabolic effects of alcohol on glycoconjugates (glycoproteins, glycolipids, and proteoglycans. We summarize the action of ethanol, acetaldehyde, reactive oxygen species (ROS, nonoxidative metabolite of alcohol — fatty acid ethyl esters (FAEEs, and the ethanol-water competition mechanism, on glycoconjugate biosynthesis, modification, transport and secretion, as well as on elimination and catabolism processes. As the majority of changes in the cellular metabolism of glycoconjugates are generally ascribed to alterations in synthesis, transport, glycosylation and secretion, the degradation and elimination processes, of which the former occurs also in extracellular matrix, seem to be underappreciated. The pathomechanisms are additionally complicated by the fact that the effect of alcohol intoxication on the glycoconjugate metabolism depends not only on the duration of ethanol exposure, but also demonstrates dose- and regional-sensitivity. Further research is needed to bridge the gap in transdisciplinary research and enhance our understanding of alcohol- and glycoconjugate-related diseases.

  12. SIRT1 and metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Katarzyna Mac-Marcjanek

    2011-04-01

    Full Text Available Both obesity and type 2 diabetes mellitus, two major components of metabolic syndrome, become healthepidemics in the world. Over the past decade, advances in understanding the role of some regulators participatingin lipid and carbohydrate homeostasis have been made.Of them, SIRT1, the mammalian orthologue of the yeast Sir2 protein has been identified. SIRT1 is a nuclearNAD+-dependent deacetylase that targets many transcriptional modulators, including PPAR-α and -γ (peroxisomeproliferator-activated receptors α and γ, PGC-1α (PPAR-γ coactivator-1α, FOXO (forkhead box O proteins,and nuclear factor κB (NF-κB, thereby this enzyme mediates a wide range of physiological processes like apoptosis,fat metabolism, glucose homeostasis, and neurodegeneration.In this article, we discuss how SIRT1 regulates lipid and carbohydrate metabolism, and insulin secretion indifferent metabolic organs/tissue, including liver, muscle, pancreas, and fat. Additionally, the role of this enzymein reduction of inflammatory signalling is highlighted.

  13. MicroRNAs in Metabolism

    DEFF Research Database (Denmark)

    Vienberg, Sara; Geiger, Julian; Madsen, Søren

    2017-01-01

    roles in cholesterol and lipid metabolism, whereas miR-103 and -107 regulates hepatic insulin sensitivity. In muscle tissue a defined number of miRNAs (miR-1, miR-133, mir-206) control myofiber type switch and induce myogenic differentiation programs. Similarly, in adipose tissue a defined number of mi......MicroRNAs (miRNAs) have within the past decade emerged as key regulators of metabolic homeostasis. Major tissues in intermediary metabolism important during development of the metabolic syndrome, such as β-cells, liver, skeletal and heart muscle as well as adipose tissue have all been shown...... to be affected by miRNAs. In the pancreatic β-cell a number of miRNAs are important in maintaining the balance between differentiation and proliferation (miR-200 and miR-29 families) and insulin exocytosis in the differentiated state is controlled by miR-7, miR-375 and miR-335. MiR-33a and -33b play crucial...

  14. Nitrogen metabolism in preterm infants

    NARCIS (Netherlands)

    J.B. van Goudoever (Hans)

    1993-01-01

    textabstractThe underlying theme of this work has been to try to understand the protein metabolism in the premature human infant, and its response to perturbations including disease and diet. Since the early work of Schoenheimer et al. it has been recognized that growth takes place as a result of

  15. Metabolic engineering in methanotrophic bacteria.

    Science.gov (United States)

    Kalyuzhnaya, Marina G; Puri, Aaron W; Lidstrom, Mary E

    2015-05-01

    Methane, as natural gas or biogas, is the least expensive source of carbon for (bio)chemical synthesis. Scalable biological upgrading of this simple alkane to chemicals and fuels can bring new sustainable solutions to a number of industries with large environmental footprints, such as natural gas/petroleum production, landfills, wastewater treatment, and livestock. Microbial biocatalysis with methane as a feedstock has been pursued off and on for almost a half century, with little enduring success. Today, biological engineering and systems biology provide new opportunities for metabolic system modulation and give new optimism to the concept of a methane-based bio-industry. Here we present an overview of the most recent advances pertaining to metabolic engineering of microbial methane utilization. Some ideas concerning metabolic improvements for production of acetyl-CoA and pyruvate, two main precursors for bioconversion, are presented. We also discuss main gaps in the current knowledge of aerobic methane utilization, which must be solved in order to release the full potential of methane-based biosystems. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  16. Metabolic enzymes in gene control

    NARCIS (Netherlands)

    E. Kozhevnikova (Elena)

    2012-01-01

    textabstractCellular compartments are believed to serve functional separation within the cell and allow it to perform multiple metabolic processes at the same time. Processes are divided between compartments with respect to the physiological requirements for a certain process. Thus, regulatory

  17. How Is Metabolic Syndrome Treated?

    Science.gov (United States)

    ... Screening and Prevention The best way to prevent metabolic syndrom is to adopt heart-healthy lifestyle changes . Make sure to schedule routine doctor visits to keep track of your cholesterol, blood pressure, and blood sugar levels. Speak with your doctor about a ... syndrome is a group of risk factors that ...

  18. Folate metabolic pathways in Leishmania

    Science.gov (United States)

    Vickers, Tim J.; Beverley, Stephen M.

    2012-01-01

    Trypanosomatid parasitic protozoans of the genus Leishmania are autotrophic for both folate and unconjugated pteridines. Leishmania salvage these metabolites from their mammalian hosts and insect vectors through multiple transporters. Within the parasite, folates are reduced by a bifunctional DHFR (dihydrofolate reductase)-TS (thymidylate synthase) and by a novel PTR1 (pteridine reductase 1), which reduces both folates and unconjugated pteridines. PTR1 can act as a metabolic bypass of DHFR inhibition, reducing the effectiveness of existing antifolate drugs. Leishmania possess a reduced set of folate-dependent metabolic reactions and can salvage many of the key products of folate metabolism from their hosts. For example, they lack purine synthesis, which normally requires 10-formyltetrahydrofolate, and instead rely on a network of purine salvage enzymes. Leishmania elaborate at least three pathways for the synthesis of the key metabolite 5,10-methylene-tetrahydrofolate, required for the synthesis of thymidylate, and for 10-formyltetrahydrofolate, whose presumptive function is for methionyl-tRNAMet formylation required for mitochondrial protein synthesis. Genetic studies have shown that the synthesis of methionine using 5-methyltetrahydrofolate is dispensable, as is the activity of the glycine cleavage complex, probably due to redundancy with serine hydroxymethyltransferase. Although not always essential, the loss of several folate metabolic enzymes results in attenuation or loss of virulence in animal models, and a null DHFR-TS mutant has been used to induce protective immunity. The folate metabolic pathway provides numerous opportunities for targeted chemotherapy, with strong potential for ‘repurposing’ of compounds developed originally for treatment of human cancers or other infectious agents. PMID:22023442

  19. Extracellular Vesicles in Metabolic Syndrome.

    Science.gov (United States)

    Martínez, M Carmen; Andriantsitohaina, Ramaroson

    2017-05-12

    Metabolic syndrome defines a cluster of interrelated risk factors for cardiovascular disease and diabetes mellitus. These factors include metabolic abnormalities, such as hyperglycemia, elevated triglyceride levels, low high-density lipoprotein cholesterol levels, high blood pressure, and obesity, mainly central adiposity. In this context, extracellular vesicles (EVs) may represent novel effectors that might help to elucidate disease-specific pathways in metabolic disease. Indeed, EVs (a terminology that encompasses microparticles, exosomes, and apoptotic bodies) are emerging as a novel mean of cell-to-cell communication in physiology and pathology because they represent a new way to convey fundamental information between cells. These microstructures contain proteins, lipids, and genetic information able to modify the phenotype and function of the target cells. EVs carry specific markers of the cell of origin that make possible monitoring their fluctuations in the circulation as potential biomarkers inasmuch their circulating levels are increased in metabolic syndrome patients. Because of the mixed components of EVs, the content or the number of EVs derived from distinct cells of origin, the mode of cell stimulation, and the ensuing mechanisms for their production, it is difficult to attribute specific functions as drivers or biomarkers of diseases. This review reports recent data of EVs from different origins, including endothelial, smooth muscle cells, macrophages, hepatocytes, adipocytes, skeletal muscle, and finally, those from microbiota as bioeffectors of message, leading to metabolic syndrome. Depicting the complexity of the mechanisms involved in their functions reinforce the hypothesis that EVs are valid biomarkers, and they represent targets that can be harnessed for innovative therapeutic approaches. © 2017 American Heart Association, Inc.

  20. Molecular control of circadian metabolic rhythms

    National Research Council Canada - National Science Library

    Siming Li; Jiandie D. Lin

    2009-01-01

    Circadian metabolic rhythms are fundamental to the control of nutrient and energy homeostasis, as well as the pathogenesis of metabolic disease, such as obesity, lipid disorders, and type 2 diabetes...

  1. Mediterranean diet and the metabolic syndrome

    NARCIS (Netherlands)

    Bos, M.B.

    2009-01-01

    Mediterranean diet and the metabolic syndrome Background: The metabolic syndrome refers to a clustering of risk factors including abdominal obesity, hyperglycaemia, low HDL-cholesterol, hypertriglyceridaemia, and hypertension and it is a risk factor for diabetes mellitus type 2 and

  2. Urban metabolism: a review of research methodologies.

    Science.gov (United States)

    Zhang, Yan

    2013-07-01

    Urban metabolism analysis has become an important tool for the study of urban ecosystems. The problems of large metabolic throughput, low metabolic efficiency, and disordered metabolic processes are a major cause of unhealthy urban systems. In this paper, I summarize the international research on urban metabolism, and describe the progress that has been made in terms of research methodologies. I also review the methods used in accounting for and evaluating material and energy flows in urban metabolic processes, simulation of these flows using a network model, and practical applications of these methods. Based on this review of the literature, I propose directions for future research, and particularly the need to study the urban carbon metabolism because of the modern context of global climate change. Moreover, I recommend more research on the optimal regulation of urban metabolic systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Metabolic advantages and vulnerabilities in brain metastases.

    Science.gov (United States)

    Ciminera, Alexandra K; Jandial, Rahul; Termini, John

    2017-10-23

    Metabolic adaptations permit tumor cells to metastasize to and thrive in the brain. Brain metastases continue to present clinical challenges due to rising incidence and resistance to current treatments. Therefore, elucidating altered metabolic pathways in brain metastases may provide new therapeutic targets for the treatment of aggressive disease. Due to the high demand for glucose in the brain, increased glycolytic activity is favored for energy production. Primary tumors that undergo Warburg-like metabolic reprogramming become suited to growth in the brain microenvironment. Indeed, elevated metabolism is a predictor of metastasis in many cancer subtypes. Specifically, metabolic alterations are seen in primary tumors that are associated with the formation of brain metastases, namely breast cancer, lung cancer, and melanoma. Because of this selective pressure, inhibitors of key metabolic factors may reduce tumor cell viability, thus exploiting metabolic pathways for cancer therapeutics. This review summarizes the metabolic advantages and vulnerabilities of brain metastases.

  4. African Journal of Endocrinology and Metabolism: Journal ...

    African Journals Online (AJOL)

    African Journal of Endocrinology and Metabolism: Journal Sponsorship. Journal Home > About the Journal > African Journal of Endocrinology and Metabolism: Journal Sponsorship. Log in or Register to get access to full text downloads.

  5. Glycaemic Control, Dyslipidaemia and Metabolic Syndrome among ...

    African Journals Online (AJOL)

    BACKGROUND: Poor glycaemic control, dyslipidaemia and metabolic syndrome are all risk factors for cardiovascular disease. OBJECTIVE: To determine the association between glycaemic control, dyslipidaemia and metabolic syndrome and their relative incidence among recently diagnosed diabetic patients in Tamale ...

  6. Genetic/metabolic effect of iron metabolism and rare anemias

    OpenAIRE

    Clara Camaschella

    2013-01-01

    Advances in iron metabolism have allowed a novel classification of iron disorders and to identify previously unknown diseases. These disorders include genetic iron overload (hemochromatosis) and inherited iron-related anemias, in some cases accompanied by iron overload. Rare inherited anemias may affect the hepcidin pathway, iron absorption, transport, utilization and recycling. Among the genetic iron-related anemias the most common form is likely the iron-refractory iron-deficiency anemia (I...

  7. Metabolic regulation of immune responses: therapeutic opportunities

    OpenAIRE

    Assmann, Nadine; Finlay, David K.

    2016-01-01

    Immune cell metabolism is dynamically regulated in parallel with the substantial changes in cellular function that accompany immune cell activation. While these changes in metabolism are important for facilitating the increased energetic and biosynthetic demands of activated cells, immune cell metabolism also has direct roles in controlling the functions of immune cells and shaping the immune response. A theme is emerging wherein nutrients, metabolic enzymes, and metabolites can act as an ext...

  8. It must be my metabolism: Metabolic control of mind

    Directory of Open Access Journals (Sweden)

    Dana M Small

    2014-07-01

    relationship between the reinforcing potency of sugared solutions and the metabolic effects that follow their consumption (16, also see the abstract of I. de Araujo. We therefore hypothesized that metabolic response provides the critical signal necessary to condition preference. To test this prediction in humans we designed a flavor nutrient conditioning study in which participants first rated their liking for novel flavored beverages and then, over a three week-long conditioning protocol, alternately ingested one of the flavored beverages with 112.5 kcal from maltodextrin, a tasteless and odorless polysaccharide that breaks down into glucose, and another flavored beverage with no calories added. Plasma glucose was measured before and after each of the drinks’ consumption as a proxy measure of metabolic response, assuming that glucose oxidation depends upon the level of circulating glucose. For each participant flavor-calorie pairings were held constant but the identity of the conditioned flavors were counterbalanced across participants. Following the exposure phase, participants’ liking of, and brain responses to, non-caloric versions of the flavors were assessed. We predicted that change in plasma glucose produced by beverage consumption during the exposure sessions would be associated with neural responses in dopamine source and target regions to the calorie predictive flavor. As predicted, response in the ventral striatum and hypothalamus to the calorie-predictive flavor (CS+ vs. non the noncaloric-predictive flavor (CS- was strongly associated with the changes in plasma glucose levels produced by ingestion of these same beverages when consumed previously either with (CS+ or without (CS- calories (17. Specifically, the greater the increase in circulating glucose occurring post ingestion of the beverage containing 112.5 kcal from maltodextrin versus the noncaloric drink, the stronger was the brain response to the CS+ compared to the CS- flavor. Importantly, because each

  9. Peculiarities of Lipid Metabolism in Children with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    N.M. Gromnatska

    2014-09-01

    Full Text Available Peculiarities of blood lipids in children with metabolic syndrome were studied. We observed 139 children aged 9 to 18 years, who formed two groups: 1st group — 85 children with metabolic syndrome on the background of abdominal obesity, 2nd group — 54 children with normal body weight. We have carried out anthropometry, defined levels of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, triglycerides, blood pressure measured. It is found that signs of dyslipidemia were significantly elevated levels of total cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, triglycerides and ratio of non-high-density lipoprotein cholesterol, total cholesterol/high-density lipoprotein cholesterol, atherogenic index, which should be used as markers in the diagnosis of metabolic syndrome in children. Relative increase of high-density lipoprotein cholesterol fractions, possibly, must be considered as compensatory reaction in response to an increase of proatherogenic cholesterol fractions with a view to their normalization.

  10. Metabolic pathways of ochratoxin A.

    Science.gov (United States)

    Wu, Qinghua; Dohnal, Vlastimil; Huang, Lingli; Kuča, Kamil; Wang, Xu; Chen, Guyue; Yuan, Zonghui

    2011-01-01

    Ochratoxin A (OTA) as a carcinogenic of group 2B to humans is produced by various fungi strains as Aspergillus and Penicillium. It is one of the most common contaminant in foodstuff. OTA is nephrotoxic, hepatotoxic, teratogenic, and immunotoxic and is assumed to cause Balkan Endemic Nephropathy (BEN), a chronic kidney disease in humans when it is digested in combination with mycotoxin citrinin. The metabolism affects greatly the fates and the toxicity of a mycotoxins in humans, animals, and plants. The understanding of the metabolism of mycotoxins by the organism as fungi, yeast, bacteria and enzymes would be very helpful for the control of the contamination by the mycotoxins in foods and feeds, and understanding of the biotransformation of the mycotoxin in the body of humans, animals, plants, microorganisms would be beneficial to the risk assessment of food safety. In animals and humans, OTA can be metabolized in the kidney, liver and intestines. Hydrolysis, hydroxylation, lactone-opening and conjugation are the major metabolic pathways. OTalpha (OTα) formed by the cleavage of the peptidic bond in OTA is a major metabolite not only in animals and humans, but also in microorganisms and enzyme systems. It is considered as a nontoxic product. However, the lactone-opened product (OP-OTA), found in rodents, is higher toxic than its parent, OTA.. (4R)-4-OH-OTA is the major hydroxy product in rodents, whereas the 4S isomer is the major in pigs. 10-OH-OTA is currently found only in rabbits. Furthermore, OTA can lose the chlorine on C-5 to produce ochratoxin B (OTB), and OTB is further to 4-OH-OTB and ochratoxin β (OTβ). Ochratoxin quinine/hydroquinone (OTQ/OTHQ) is the metabolite of OTA in animals. In addition, the conjugates of OTA such as hexose and pentose conjugates can be found in animals. Such more polar metabolites make OTA to eliminate faster. Currently, a debate exits on the formation of OTA-DNA adducts. Plants can metabolize OTA as well. OH-OTA methyl ester

  11. Intestinal Microbiota and Metabolic Diseases: Pharmacological Implications.

    Science.gov (United States)

    Shen, Liang; Ji, Hong-Fang

    2016-03-01

    An increasing number of studies show that alterations in intestinal microbiota are linked with metabolic diseases. Here, we propose that intestinal microbiota regulation by polyphenols may be an important mechanism underlying their therapeutic benefits for metabolic diseases. This helps elucidate the intriguing pharmacology of polyphenols and optimize the treatment of metabolic diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Imaging myocardial metabolism and ischemic memory.

    Science.gov (United States)

    Taegtmeyer, Heinrich; Dilsizian, Vasken

    2008-08-01

    The advent of myocardial metabolic imaging more than 30 years ago ushered in a paradigm shift in the clinical management of patients with ischemic and nonischemic heart disease. A classic example is the so-called metabolic memory of altered glucose and fatty acid metabolism in regions of myocardial ischemia and reperfusion. At the cellular level, metabolic memory is driven by changes in the activities and expression of a host of metabolic enzymes, including reactivation of the fetal gene program. The future of metabolic imaging will require a more-refined understanding of the pathways of metabolic adaptation and maladaptation of the heart. Recent evidence suggests that metabolic signals alter metabolic fluxes and give rise to specific metabolic patterns that, in turn, lead to changes in translational and/or transcriptional activities in the cardiac myocyte. In other words, metabolism provides a link between environmental stimuli and a host of intracellular signaling pathways. This concept has not yet been fully explored in vivo, although metabolic adaptation represents the earliest response to myocardial ischemia and left ventricular remodeling.

  13. Can resveratrol help to maintain metabolic health?

    NARCIS (Netherlands)

    Schrauwen, P.; Timmers, S.

    2014-01-01

    The number of people suffering from metabolic diseases is dramatically increasing worldwide. This stresses the need for new therapeutic strategies to combat this growing epidemic of metabolic diseases. A reduced mitochondrial function is one of the characteristics of metabolic diseases and therefore

  14. [Application of metabolic flux ratio analysis in metabolic engineering--a review].

    Science.gov (United States)

    Hua, Qiang; Yang, Chen

    2009-09-01

    Intracellular metabolic fluxes are important to understand metabolic characteristics of cells and to direct metabolic engineering strategies. Because intracellular fluxes cannot be directly assessed, isotope experiments are usually conducted to trace metabolic fluxes. The flux-ratio analysis can reflect high biochemical veracity, be employed to identify the topology of the networks, and offer greatly reduced computational expense for flux determination. In order to apply this metabolic analysis method to better elucidate more cell systems, we discussed in this study the principles, experiments and assays, data interpretation, and other issues that should be considered in flux ratio determination, metabolic flux quantification and its metabolic engineering applications.

  15. Progress in plant metabolic engineering.

    Science.gov (United States)

    Capell, Teresa; Christou, Paul

    2004-04-01

    Over the past few years, there has been a growing realization that metabolic pathways must be studied in the context of the whole cell rather than at the single pathway level, and that even the simplest modifications can send ripples throughout the entire system. Attention has therefore shifted away from reductionist, single-gene engineering strategies and towards more complex approaches involving the simultaneous overexpression and/or suppression of multiple genes. The use of regulatory factors to control the abundance or activity of several enzymes is also becoming more widespread. In combination with emerging methods to model metabolic pathways, this should facilitate the enhanced production of natural products and the synthesis of novel materials in a predictable and useful manner.

  16. Medicolegal aspects of tetrazepam metabolism.

    Science.gov (United States)

    Pavlic, Marion; Libiseller, Kathrin; Grubwieser, Petra; Schubert, Heinrich; Rabl, Walter

    2007-05-01

    The benzodiazepine tetrazepam is primarily muscle relaxant with comparably lower central sedating effects and is therefore commonly prescribed for muscle spasms of different origins. To evaluate tetrazepam metabolism, a study was conducted with ten healthy volunteers. Blood and urine samples were regularly collected after the intake of 50 mg tetrazepam. Toxicological analyses revealed that tetrazepam is also metabolized to diazepam and further to nordazepam, which has not yet been reported. Tetrazepam and diazepam could be detected in urine samples at least 72 h after intake, the diazepam concentration being 33% (+/-14% SD), on average, of the tetrazepam concentration. On the basis of three case histories, the importance of the detection of these newly described metabolites is shown as necessary to prevent false accusations and potential negative legal consequences for examined persons.

  17. Spontaneous emergence of a metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Bagley, R.J.; Farmer, J.D. (Los Alamos National Lab., NM (USA) Santa Fe Inst., NM (USA))

    1990-01-01

    Networks of catalyzed reactions with nonlinear feedback have been proposed to play an important role in the origin of life. We investigate this possibility in a polymer chemistry with catalyzed cleavage and condensation reactions. We study the properties of a well-stirred reactor driven away from equilibrium by the flow of mass. Under appropriate non-equilibrium conditions. The nonlinear feedback of the reaction network focuses the material of the system into a few specific polymer species. The network of catalytic reactions digests'' the material of its environment, incorporating it into its own form. We call the result an autocatalytic metabolism. Under some variations it persists almost unchanged, while in other cases it dies. We argue that the dynamical stability of autocatalytic metabolisms gives them regenerative properties that allow them to repair themselves and to propagate through time. 43 refs., 16 figs., 3 tabs.

  18. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    Phthalates are synthetic compounds widely used as plasticisers, solvents and additives in many consumer products. Several animal studies have shown that some phthalates possess endocrine disrupting effects. Some of the effects of phthalates seen in rats are due to testosterone lowering effects...... on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...... phthalates, but our knowledge about metabolic distribution in the body and other biological fluids, including breast milk, is limited. Compared to urine, human breast milk contains relatively more of the hydrophobic phthalates, such as di-n-butyl phthalate and the longer-branched, di(2-ethylhexyl) phthalate...

  19. C2 metabolism in Euglena.

    Science.gov (United States)

    Nakazawa, Masami

    2017-01-01

    Euglenoids are able to assimilate fatty acids and alcohols with various carbon-chain lengths, and ethanol is known to be one of the best carbon sources to support the growth of Euglena gracilis. Ethanol is first oxidized to acetate by the sequential reactions of alcohol dehydrogenase and acetaldehyde dehydrogenase in the mitochondria, and then converted to acetyl coenzyme A (acetyl-CoA). Acetyl-CoA is metabolized through the glyoxylate cycle which is a modified tricarboxylic acid (TCA) cycle in which isocitrate lyase (ICL) and malate synthase (MS) function to bypass the two decarboxylation steps of the TCA cycle, enabling the net synthesis of carbohydrates from C2 compounds. ICL and MS form a unique bifunctional enzyme localized in Euglena mitochondria, not in glyoxysome as in other eukaryotes. The unique glyoxylate and glycolate metabolism during photorespiration is also discussed in this chapter.

  20. PET Metabolic Biomarkers for Cancer

    Directory of Open Access Journals (Sweden)

    Etienne Croteau

    2016-01-01

    Full Text Available The body's main fuel sources are fats, carbohydrates (glucose, proteins, and ketone bodies. It is well known that an important hallmark of cancer cells is the overconsumption of glucose. Positron emission tomography (PET imaging using the glucose analog 18 F-fluorodeoxyglucose ( 18 F-FDG has been a powerful cancer diagnostic tool for many decades. Apart from surgery, chemotherapy and radiotherapy represent the two main domains for cancer therapy, targeting tumor proliferation, cell division, and DNA replication–-all processes that require a large amount of energy. Currently, in vivo clinical imaging of metabolism is performed almost exclusively using PET radiotracers that assess oxygen consumption and mechanisms of energy substrate consumption. This paper reviews the utility of PET imaging biomarkers for the detection of cancer proliferation, vascularization, metabolism, treatment response, and follow-up after radiation therapy, chemotherapy, and chemotherapy-related side effects.

  1. Metabolic Effects of Intermittent Fasting.

    Science.gov (United States)

    Patterson, Ruth E; Sears, Dorothy D

    2017-08-21

    The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

  2. Circadian rhythms, sleep, and metabolism.

    Science.gov (United States)

    Huang, Wenyu; Ramsey, Kathryn Moynihan; Marcheva, Biliana; Bass, Joseph

    2011-06-01

    The discovery of the genetic basis for circadian rhythms has expanded our knowledge of the temporal organization of behavior and physiology. The observations that the circadian gene network is present in most living organisms from eubacteria to humans, that most cells and tissues express autonomous clocks, and that disruption of clock genes results in metabolic dysregulation have revealed interactions between metabolism and circadian rhythms at neural, molecular, and cellular levels. A major challenge remains in understanding the interplay between brain and peripheral clocks and in determining how these interactions promote energy homeostasis across the sleep-wake cycle. In this Review, we evaluate how investigation of molecular timing may create new opportunities to understand and develop therapies for obesity and diabetes.

  3. Metabolism of biologics: biotherapeutic proteins.

    Science.gov (United States)

    Hamuro, Lora L; Kishnani, Narendra S

    2012-01-01

    Recombinant therapeutic protein drugs have now been in clinical use for nearly three decades and have advanced considerably in complexity over this time period. Regulatory approvals of some early pioneering protein drugs did not require characterization of metabolism, but more recently regulatory expectations and guidance have appropriately evolved. Sponsors may now be expected to investigate metabolism of newer biologics as the structural complexity of proteins has increased markedly, particularly with the introduction of conjugated and modified proteins. This review discusses the value and need for metabolite characterization of some therapeutic proteins by presenting select examples. Regulatory expectations will undoubtedly evolve further with the development of other novel macromolecular biologic therapeutics based on modified nucleic acids, novel conjugated lipids and polysaccharides.

  4. [FETAL PROGRAMMING OF METABOLIC DISORDERS].

    Science.gov (United States)

    Varadinova, M R; Metodieva, R; Boyadzhieva, N

    2015-01-01

    Our knowledge of fetal programming has developed notably over the years and recent data suggest that an unbalanced diet prior and during pregnancy can have early-onset and long-lasting consequences on the health of the offspring. Specific negative influences of high dietary glucose and lipid consumption, as well as undernutrition, are associated with development of metabolic syndrome, insulin resistance and diabetes in the offspring. The mechanisms underlying the effects of maternal hyperglycemia on the fetus may involve structural, metabolic and epigenetic changes. The aim of this review is to illustrate how adverse intrauterine environment may influence molecular modifications in the fetus and cause epigenetic alterations in particular. It has been demonstrated that prenatal epigenetic modifications may be linked to the pathogenesis and progression of the adult chronic disorders. Studies on epigenetic alterations will contribute to a better understanding of the long-term effects of in utero exposure and may open new perspectives for disease prevention and treatment.

  5. Metabolic scaling in solid tumours

    Science.gov (United States)

    Milotti, E.; Vyshemirsky, V.; Sega, M.; Stella, S.; Chignola, R.

    2013-06-01

    Tumour metabolism is an outstanding topic of cancer research, as it determines the growth rate and the global activity of tumours. Recently, by combining the diffusion of oxygen, nutrients, and metabolites in the extracellular environment, and the internal motions that mix live and dead cells, we derived a growth law of solid tumours which is linked to parameters at the cellular level. Here we use this growth law to obtain a metabolic scaling law for solid tumours, which is obeyed by tumours of different histotypes both in vitro and in vivo, and we display its relation with the fractal dimension of the distribution of live cells in the tumour mass. The scaling behaviour is related to measurable parameters, with potential applications in the clinical practice.

  6. Toward engineering synthetic microbial metabolism.

    Science.gov (United States)

    McArthur, George H; Fong, Stephen S

    2010-01-01

    The generation of well-characterized parts and the formulation of biological design principles in synthetic biology are laying the foundation for more complex and advanced microbial metabolic engineering. Improvements in de novo DNA synthesis and codon-optimization alone are already contributing to the manufacturing of pathway enzymes with improved or novel function. Further development of analytical and computer-aided design tools should accelerate the forward engineering of precisely regulated synthetic pathways by providing a standard framework for the predictable design of biological systems from well-characterized parts. In this review we discuss the current state of synthetic biology within a four-stage framework (design, modeling, synthesis, analysis) and highlight areas requiring further advancement to facilitate true engineering of synthetic microbial metabolism.

  7. Toward Engineering Synthetic Microbial Metabolism

    Directory of Open Access Journals (Sweden)

    George H. McArthur

    2010-01-01

    Full Text Available The generation of well-characterized parts and the formulation of biological design principles in synthetic biology are laying the foundation for more complex and advanced microbial metabolic engineering. Improvements in de novo DNA synthesis and codon-optimization alone are already contributing to the manufacturing of pathway enzymes with improved or novel function. Further development of analytical and computer-aided design tools should accelerate the forward engineering of precisely regulated synthetic pathways by providing a standard framework for the predictable design of biological systems from well-characterized parts. In this review we discuss the current state of synthetic biology within a four-stage framework (design, modeling, synthesis, analysis and highlight areas requiring further advancement to facilitate true engineering of synthetic microbial metabolism.

  8. Inherited disorders of GABA metabolism

    OpenAIRE

    Pearl, Phillip L; Hartka, Thomas R; Cabalza, Jessica L; Taylor, Jacob; Gibson, Michael K

    2006-01-01

    The inherited disorders of γ-amino butyric acid (GABA) metabolism require an increased index of clinical suspicion. The known genetic disorders are GABA-transaminase deficiency, succinic semialdehyde dehydrogenase (SSADH) deficiency and homocarnosinosis. A recent link has also been made between impaired GABA synthesis and nonsyndromic cleft lip, with or without cleft palate. SSADH deficiency is the most commonly occurring of the inherited disorders of neurotransmitters. The disorder has a non...

  9. Industry as a metabolic activity.

    OpenAIRE

    Smart, B.

    1992-01-01

    The concept of "industrial economic metabolism" can provide a bridge to better understanding between environmentalists and industry. In nature each individual or species reacts to natural stimuli, competing with others for resources, extending its domain until it loses comparative advantage and comes to equilibrium with an adjacent competitor. Those species that succeed over time flourish; those that do not, diminish or disappear. Nature's rule book has no moral or ethical ingredient beyond s...

  10. Phytoestrogens and the metabolic syndrome.

    Science.gov (United States)

    Jungbauer, Alois; Medjakovic, Svjetlana

    2014-01-01

    Phytoestrogens are a diverse class of non-steroidal compounds that have an affinity for estrogen receptors α and β, for the peroxisome proliferator-activated receptor (PPAR) family and for the aryl hydrocarbon receptor. Examples of phytoestrogens include prenylated flavonoids, isoflavones, coumestans and lignans. Many phytoestrogens counteract the cellular derailments that are responsible for the development of metabolic syndrome. Here we propose a mechanism of action which is based on five pillars/principles. First, phytoestrogens are involved in the downregulation of pro-inflammatory cytokines, such as COX-2 and iNOS, by activating PPAR and by inhibiting IκB activation. Second, they increase reverse cholesterol transport, which is mediated by PPARγ. Third, phytoestrogens increase insulin sensitivity, which is mediated via PPARα. Fourth, they exert antioxidant effects by activating antioxidant genes through KEAP. Fifth, phytoestrogens increase energy expenditure by affecting AMP-activated kinase signaling cascades, which are responsible for the inhibition of adipogenesis. In addition to these effects, which have been demonstrated in vivo and in clinical trials, other effects, such as eNOS activation, may also be important. Some plant extracts from soy, red clover or licorice can be described as panPPAR activators. Fetal programming for metabolic syndrome has been hypothesized; thus, the consumption of dietary phytoestrogens during pregnancy may be relevant. Extracts from soy, red clover or licorice oil have potential as plant-derived medicines that could be used to treat polycystic ovary syndrome, a disease linked to hyperandrogenism and obesity, although clinical trials have not yet been conducted. Phytoestrogens may help prevent metabolic syndrome, although intervention studies will be always be ambiguous, because physical activity and reduced calorie consumption also have a significant impact. Nevertheless, extracts rich in phytoestrogens may be an

  11. Identification of Metabolic Pathway Systems

    Directory of Open Access Journals (Sweden)

    Sepideh eDolatshahi

    2016-02-01

    Full Text Available The estimation of parameters in even moderately large biological systems is a significant challenge. This challenge is greatly exacerbated if the mathematical formats of appropriate process descriptions are unknown. To address this challenge, the method of dynamic flux estimation (DFE was proposed for the analysis of metabolic time series data. Under ideal conditions, the first phase of DFE yields numerical representations of all fluxes within a metabolic pathway system, either as values at each time point or as plots against their substrates and modulators. However, this numerical result does not reveal the mathematical format of each flux. Thus, the second phase of DFE selects functional formats that are consistent with the numerical trends obtained from the first phase. While greatly facilitating metabolic data analysis, DFE is only directly applicable if the pathway system contains as many dependent variables as fluxes. Because most actual systems contain more fluxes than metabolite pools, this requirement is seldom satisfied. Auxiliary methods have been proposed to alleviate this issue, but they are not general. Here we propose strategies that extend DFE toward general, slightly underdetermined pathway systems.

  12. Metabolic disorders mimicking Reye's syndrome.

    Science.gov (United States)

    Chang, P F; Huang, S F; Hwu, W L; Hou, J W; Ni, Y H; Chang, M H

    2000-04-01

    Several metabolic disorders such as encephalopathy and hepatic dysfunction have been described as Reye's-like syndrome because they present with similar clinical manifestations that mimic Reye's syndrome. We performed a retrospective study to explore the underlying metabolic etiologies of Reye's-like syndrome in patients treated at National Taiwan University Hospital. From January 1991 to June 1998, 19 children with a syndrome fitting the Reye's-like syndrome description were identified for study. Urine organic acid analysis, plasma amino acid analysis, liver pathology, and skin fibroblast enzyme assays were studied during the acute stage of illness. The etiologies of patients' syndromes included urea cycle disorders (n = 7), glycogen storage disease type Ia (4), primary carnitine deficiency (2), hereditary fructose intolerance (1), methylmalonic acidemia (2), and 3-hydroxy-3-methylglutaric acidemia (1). Fatty acid oxidation defects were suspected in the remaining two cases. A significant number of patients who present with Reye's-like syndrome have an underlying inherited metabolic disorder. In patients with Reye's-like syndrome, an accurate diagnosis is essential to ensure normal growth and development and to prevent recurrence of the condition.

  13. Bone Metabolism after Bariatric Surgery

    Science.gov (United States)

    Yu, Elaine W.

    2014-01-01

    Bariatric surgery is a popular and effective treatment for severe obesity, but may have negative effects on the skeleton. This review summarizes changes in bone density and bone metabolism from animal and clinical studies of bariatric surgery, with specific attention to Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB), and sleeve gastrectomy (SG). Skeletal imaging artifacts from obesity and weight loss are also considered. Despite challenges in bone density imaging, the preponderance of evidence suggests that bariatric surgery procedures have negative skeletal effects that persist beyond the first year of surgery, and that these effects vary by surgical type. The long-term clinical implications and current clinical recommendations are presented. Further study is required to determine mechanisms of bone loss after bariatric surgery. Although early studies focused on calcium/vitamin D metabolism and mechanical unloading of the skeleton, it seems likely that surgically-induced changes in the hormonal and metabolic profile may be responsible for the skeletal phenotypes observed after bariatric surgery. PMID:24677277

  14. Targeting ceramide metabolism in obesity.

    Science.gov (United States)

    Aburasayn, Hanin; Al Batran, Rami; Ussher, John R

    2016-08-01

    Obesity is a major health concern that increases the risk for insulin resistance, type 2 diabetes (T2D), and cardiovascular disease. Thus, an enormous research effort has been invested into understanding how obesity-associated dyslipidemia and obesity-induced alterations in lipid metabolism increase the risk for these diseases. Accordingly, it has been proposed that the accumulation of lipid metabolites in organs such as the liver, skeletal muscle, and heart is critical to these obesity-induced pathologies. Ceramide is one such lipid metabolite that accumulates in tissues in response to obesity, and both pharmacological and genetic strategies that reduce tissue ceramide levels yield salutary actions on overall metabolic health. We will review herein why ceramide accumulates in tissues during obesity and how an increase in intracellular ceramide impacts cellular signaling and function as well as potential mechanisms by which reducing intracellular ceramide levels improves insulin resistance, T2D, atherosclerosis, and heart failure. Because a reduction in skeletal muscle ceramide levels is frequently associated with improvements in insulin sensitivity in humans, the beneficial findings reported for reducing ceramides in preclinical studies may have clinical application in humans. Therefore, modulating ceramide metabolism may be a novel, exciting target for preventing and/or treating obesity-related diseases. Copyright © 2016 the American Physiological Society.

  15. Sirtuins Link Inflammation and Metabolism

    Directory of Open Access Journals (Sweden)

    Vidula T. Vachharajani

    2016-01-01

    Full Text Available Sirtuins (SIRT, first discovered in yeast as NAD+ dependent epigenetic and metabolic regulators, have comparable activities in human physiology and disease. Mounting evidence supports that the seven-member mammalian sirtuin family (SIRT1–7 guard homeostasis by sensing bioenergy needs and responding by making alterations in the cell nutrients. Sirtuins play a critical role in restoring homeostasis during stress responses. Inflammation is designed to “defend and mend” against the invading organisms. Emerging evidence supports that metabolism and bioenergy reprogramming direct the sequential course of inflammation; failure of homeostasis retrieval results in many chronic and acute inflammatory diseases. Anabolic glycolysis quickly induced (compared to oxidative phosphorylation for ROS and ATP generation is needed for immune activation to “defend” against invading microorganisms. Lipolysis/fatty acid oxidation, essential for cellular protection/hibernation and cell survival in order to “mend,” leads to immune repression. Acute/chronic inflammations are linked to altered glycolysis and fatty acid oxidation, at least in part, by NAD+ dependent function of sirtuins. Therapeutically targeting sirtuins may provide a new class of inflammation and immune regulators. This review discusses how sirtuins integrate metabolism, bioenergetics, and immunity during inflammation and how sirtuin-directed treatment improves outcome in chronic inflammatory diseases and in the extreme stress response of sepsis.

  16. Phosphocalcic metabolism after biliopancreatic diversion.

    Science.gov (United States)

    Lozano, O; García-Díaz, J D; Cancer, E; Arribas, I; Rubio, J L; González-García, I; Galván, M; Alvarez, J; Martín-Duce, A

    2007-05-01

    Malabsorptive techniques to treat morbid obesity have been followed by alterations in phosphocalcic metabolism. Knowledge of the preoperative situation is important to assess the influence of these techniques on phosphocalcic metabolism and to consider treatments for these alterations. 61 consecutive morbidly obese patients (50 women, 11 men, age 19 to 63 years) having had biliopancreatic diversion (BPD) were studied in a prospective manner. Preoperative and postoperative levels of calcium, phosphorus, 25-hydroxyvitamin D, tartrate resistant acid phosphate, plasma parathormone (PTH), tubular absorption of phosphate, and urinary calcium and pyridinolines were analyzed, as well as the potential risk factors for their alterations. Follow-up of all patients was a minimum of 4 years. Before BPD, 42.3% of patients presented an increase in PTH and 54% a decrease in the 25-OH vitamin D, but the values of calcium and plasma phosphorus maintained at normal level. 81.8% of the patients with an increase in the PTH maintained high levels after BPD, while 60% of those with a normal preoperative PTH also presented hyperparathyroidism 4 years after the intervention. A correlation between the levels of plasma PTH and body mass index was not found. Morbid obesity is accompanied by a high percentage of hyperparathyroidism. BPD produces malabsorption of vitamin D during the first years, favoring the persistence or appearance of hyperparathyroidism. It is important to recognize and treat the secondary hyperparathyroidism. The postoperative period could necessitate more energetic interventions to get more efficient control of the phosphocalcic metabolism.

  17. Metabolic alkalosis: pathogenesis and physiopathology

    Directory of Open Access Journals (Sweden)

    Mario Tarantino

    2008-12-01

    Full Text Available Metabolic alkalosis is an acid-base disorder frequently encountered in hospitalised patients, particularly those in critical conditions and is not infrequently complicated by mixed acid-base disorders. This disorder can have serious clinical consequences, especially on the cardiovascular and central nervous systems. The disorder’s gravity is partly due to the precarious nature of the defence and compensation processes the body is able to provide to combat the alteration in the blood’s pH. Metabolic alkalosis is just one, secondary component of a complex water and electrolyte balance disorder, on which the maintenance of the acid-base disorder depends. Metabolic alkalosis can be a complication of various somewhat diverse conditions and is often common in hospital settings. A multitude of pathophysiological factors contribute to maintaining the acid-base disorder: these factors influence and feed one another. As the resolution of the acid-base disorder depends on the correction of these factors, it is essential to know their exact mechanisms in order to undertake the most appropriate therapeutic action.

  18. A Quick Reference on Hyperchloremic Metabolic Acidosis.

    Science.gov (United States)

    Funes, Silvia; de Morais, Helio Autran

    2017-03-01

    Metabolic acidosis results from an increase in the concentration of a strong anion. Metabolic acidosis is divided into hyperchloremic metabolic acidosis and high anion gap acidosis based on the changes in the anion gap. Hyperchloremic metabolic acidosis is the result of chloride retention, excessive loss of sodium relative to chloride, or excessive gain of chloride relative to sodium. Clinical signs are related to the underlying disease that accompanies the metabolic acidosis. Treatment of hyperchloremic acidosis is based on addressing the underlying disease process. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Lipid metabolism in experimental animals

    Directory of Open Access Journals (Sweden)

    Sánchez-Muñiz, Francisco J.

    1998-08-01

    Full Text Available Publications are scarce in the way in chich metabolic processes are affected by the ingestion of heated fats used to prepare food. Similarly studies measuring metabolic effects of the consumption on fried food are poorly known. The purpose of this presentation is to summarize information on frying fats and frying foods upon lipid metabolism in experimental animals. Food consumption is equivalent or even higher when oils or the fat content of frying foods are poorly alterated decreasing their acceptability when their alteration degree increase. After 4hr. experiment the digestibility and absorption coefficients of a single dosis of thermooxidized oils were significantly decreased in rats, however the digestive utilization of frying thermooxidized oils included in diets showed very little change in comparison with unused oils by feeding trials on rats. Feeding rats different frying fats induced a slight hypercholesterolemic effect being the magnitude of this effect related to the linoleic decrease in diet produced by frying. However HDL, the main rat-cholesterol carrier, also increased, thus the serum cholesterol/HDL-cholesterol ratio did not change. Results suggest that rats fed frying fats adapt their lipoprotein metabolism increasing the number of HDL particles. Deep fat frying deeply changed the fatty acid composition of foods, being possible to increase their n-9 or n-6 fatty acid and to decrease the saturated fatty acid contents by frying. When olive oil-and sunflower oil-fried sardines were used as the only protein and fat sources of rats-diets in order to prevent the dietary hypercholesterolemia it was provided that both fried-sardine diets showed a powerful check effect on the cholesterol raising effect induced by dietary cholesterol. The negative effect of feeding rats cholesterol plus bovine bile to induce hypercholesterolemia on some cell-damage markers such as lactate dehydrogenase, transaminases, alkaline phosphatase, was

  20. Industry as a metabolic activity.

    Science.gov (United States)

    Smart, B

    1992-02-01

    The concept of "industrial economic metabolism" can provide a bridge to better understanding between environmentalists and industry. In nature each individual or species reacts to natural stimuli, competing with others for resources, extending its domain until it loses comparative advantage and comes to equilibrium with an adjacent competitor. Those species that succeed over time flourish; those that do not, diminish or disappear. Nature's rule book has no moral or ethical ingredient beyond self-interest. Corporate metabolisms are remarkably similar to those of nature. They too react to stimuli, collect and use resources, and grow or perish based on how effectively they compete. Corporate management recognizes and responds naturally and efficiently to cost and price signals. Through them it selects resources and converts them into useful products. The efficiency with which this is done is measured by profit, the lifeblood of the corporation and its means of growth. Profit thus provides a discipline on corporate behavior, encouraging efficient performers, and, by its absence, weeding out others. Unfettered by influences other than economics, the path to corporate success is unlikely to be a compassionate one. The dilemma of the manager is that to do what is socially "right" often conflicts with what must be done to survive and prosper. Fortunately, corporations' behavior can be altered by society when their purely economic role comes into conflict with other human values. The environment and the economy are not separate systems but intertwined to form a complex natural and social setting. The human-designed economic system depends on natural resource inputs, and in turn its metabolic wastes can overload the ecological system, threatening the long-term survivability of both. Increasing concern for the environment now gives the farsighted manager new latitude. There are competitive benefits in some pollution prevention. But there are not sufficiently strong forces to

  1. ER stress and hepatic lipid metabolism

    Directory of Open Access Journals (Sweden)

    Huiping eZhou

    2014-05-01

    Full Text Available The endoplasmic reticulum (ER is an important player in regulating protein synthesis and lipid metabolism. Perturbation of ER homeostasis, referred as ER stress, has been linked to numerous pathological conditions, such as inflammation, cardiovascular diseases and metabolic disorders. The liver plays a central role in regulating nutrient and lipid metabolism. Accumulating evidence implicates that ER stress disrupts lipid metabolism and induces hepatic lipotoxicity. Here, we review the major ER stress signaling pathways, how ER stress contributes to the dysregulation of hepatic lipid metabolism, and the potential causative mechanisms of ER stress in hepatic lipotoxicity. Understanding the role of ER stress in hepatic metabolism may lead to the identification of new therapeutic targets for metabolic diseases.

  2. Interplay between oxidant species and energy metabolism

    Science.gov (United States)

    Quijano, Celia; Trujillo, Madia; Castro, Laura; Trostchansky, Andrés

    2015-01-01

    It has long been recognized that energy metabolism is linked to the production of reactive oxygen species (ROS) and critical enzymes allied to metabolic pathways can be affected by redox reactions. This interplay between energy metabolism and ROS becomes most apparent during the aging process and in the onset and progression of many age-related diseases (i.e. diabetes, metabolic syndrome, atherosclerosis, neurodegenerative diseases). As such, the capacity to identify metabolic pathways involved in ROS formation, as well as specific targets and oxidative modifications is crucial to our understanding of the molecular basis of age-related diseases and for the design of novel therapeutic strategies. Herein we review oxidant formation associated with the cell's energetic metabolism, key antioxidants involved in ROS detoxification, and the principal targets of oxidant species in metabolic routes and discuss their relevance in cell signaling and age-related diseases. PMID:26741399

  3. Genome-scale modeling for metabolic engineering.

    Science.gov (United States)

    Simeonidis, Evangelos; Price, Nathan D

    2015-03-01

    We focus on the application of constraint-based methodologies and, more specifically, flux balance analysis in the field of metabolic engineering, and enumerate recent developments and successes of the field. We also review computational frameworks that have been developed with the express purpose of automatically selecting optimal gene deletions for achieving improved production of a chemical of interest. The application of flux balance analysis methods in rational metabolic engineering requires a metabolic network reconstruction and a corresponding in silico metabolic model for the microorganism in question. For this reason, we additionally present a brief overview of automated reconstruction techniques. Finally, we emphasize the importance of integrating metabolic networks with regulatory information-an area which we expect will become increasingly important for metabolic engineering-and present recent developments in the field of metabolic and regulatory integration.

  4. Metabolic consequences of sleep and circadian disorders

    Science.gov (United States)

    Depner, Christopher M.; Stothard, Ellen R.; Wright, Kenneth P.

    2014-01-01

    Sleep and circadian rhythms modulate or control daily physiological patterns with importance for normal metabolic health. Sleep deficiencies associated with insufficient sleep schedules, insomnia with short-sleep duration, sleep apnea, narcolepsy, circadian misalignment, shift work, night eating syndrome and sleep-related eating disorder may all contribute to metabolic dysregulation. Sleep deficiencies and circadian disruption associated with metabolic dysregulation may contribute to weight gain, obesity, and type 2 diabetes potentially by altering timing and amount of food intake, disrupting energy balance, inflammation, impairing glucose tolerance and insulin sensitivity. Given the rapidly increasing prevalence of metabolic diseases, it is important to recognize the role of sleep and circadian disruption in the development, progression, and morbidity of metabolic disease. Some findings indicate sleep treatments and countermeasures improve metabolic health, but future clinical research investigating prevention and treatment of chronic metabolic disorders through treatment of sleep and circadian disruption is needed. PMID:24816752

  5. Metabolism

    Science.gov (United States)

    ... the skin, kidneys, lungs, and intestines. continue The Endocrine System Several of the hormones of the endocrine system ... Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine System What Are Glands? Diabetes Center Other Diseases ...

  6. Metabolism

    Science.gov (United States)

    ... carbohydrates and fats) to release energy. This energy release provides fuel for anabolism, heats the body, and enables the muscles to contract and the body to move. As complex chemical units are broken down into more simple substances, the waste products released in the process of ...

  7. The human metabolic reconstruction Recon 1 directs hypotheses of novel human metabolic functions

    Science.gov (United States)

    2011-01-01

    Background Metabolic network reconstructions formalize our knowledge of metabolism. Gaps in these networks pinpoint regions of metabolism where biological components and functions are "missing." At the same time, a major challenge in the post genomic era involves characterisation of missing biological components to complete genome annotation. Results We used the human metabolic network reconstruction RECON 1 and established constraint-based modelling tools to uncover novel functions associated with human metabolism. Flux variability analysis identified 175 gaps in RECON 1 in the form of blocked reactions. These gaps were unevenly distributed within metabolic pathways but primarily found in the cytosol and often caused by compounds whose metabolic fate, rather than production, is unknown. Using a published algorithm, we computed gap-filling solutions comprised of non-organism specific metabolic reactions capable of bridging the identified gaps. These candidate solutions were found to be dependent upon the reaction environment of the blocked reaction. Importantly, we showed that automatically generated solutions could produce biologically realistic hypotheses of novel human metabolic reactions such as of the fate of iduronic acid following glycan degradation and of N-acetylglutamate in amino acid metabolism. Conclusions The results demonstrate how metabolic models can be utilised to direct hypotheses of novel metabolic functions in human metabolism; a process that we find is heavily reliant upon manual curation and biochemical insight. The effectiveness of a systems approach for novel biochemical pathway discovery in mammals is demonstrated and steps required to tailor future gap filling algorithms to mammalian metabolic networks are proposed. PMID:21962087

  8. Metabolic cartography: experimental quantification of metabolic fluxes from isotopic labelling studies.

    Science.gov (United States)

    O'Grady, John; Schwender, Jörg; Shachar-Hill, Yair; Morgan, John A

    2012-03-01

    For the past decade, flux maps have provided researchers with an in-depth perspective on plant metabolism. As a rapidly developing field, significant headway has been made recently in computation, experimentation, and overall understanding of metabolic flux analysis. These advances are particularly applicable to the study of plant metabolism. New dynamic computational methods such as non-stationary metabolic flux analysis are finding their place in the toolbox of metabolic engineering, allowing more organisms to be studied and decreasing the time necessary for experimentation, thereby opening new avenues by which to explore the vast diversity of plant metabolism. Also, improved methods of metabolite detection and measurement have been developed, enabling increasingly greater resolution of flux measurements and the analysis of a greater number of the multitude of plant metabolic pathways. Methods to deconvolute organelle-specific metabolism are employed with increasing effectiveness, elucidating the compartmental specificity inherent in plant metabolism. Advances in metabolite measurements have also enabled new types of experiments, such as the calculation of metabolic fluxes based on (13)CO(2) dynamic labelling data, and will continue to direct plant metabolic engineering. Newly calculated metabolic flux maps reveal surprising and useful information about plant metabolism, guiding future genetic engineering of crops to higher yields. Due to the significant level of complexity in plants, these methods in combination with other systems biology measurements are necessary to guide plant metabolic engineering in the future.

  9. Metabolic cartography: experimental quantification of metabolic fluxes from isotopic labelling studies

    Energy Technology Data Exchange (ETDEWEB)

    O' Grady J.; Schwender J.; Shachar-Hill, Y.; Morgan, J. A.

    2012-03-01

    For the past decade, flux maps have provided researchers with an in-depth perspective on plant metabolism. As a rapidly developing field, significant headway has been made recently in computation, experimentation, and overall understanding of metabolic flux analysis. These advances are particularly applicable to the study of plant metabolism. New dynamic computational methods such as non-stationary metabolic flux analysis are finding their place in the toolbox of metabolic engineering, allowing more organisms to be studied and decreasing the time necessary for experimentation, thereby opening new avenues by which to explore the vast diversity of plant metabolism. Also, improved methods of metabolite detection and measurement have been developed, enabling increasingly greater resolution of flux measurements and the analysis of a greater number of the multitude of plant metabolic pathways. Methods to deconvolute organelle-specific metabolism are employed with increasing effectiveness, elucidating the compartmental specificity inherent in plant metabolism. Advances in metabolite measurements have also enabled new types of experiments, such as the calculation of metabolic fluxes based on {sup 13}CO{sub 2} dynamic labelling data, and will continue to direct plant metabolic engineering. Newly calculated metabolic flux maps reveal surprising and useful information about plant metabolism, guiding future genetic engineering of crops to higher yields. Due to the significant level of complexity in plants, these methods in combination with other systems biology measurements are necessary to guide plant metabolic engineering in the future.

  10. Metabolic cartography: experimental quantification of metabolic fluxes from isotopic labelling studies

    Energy Technology Data Exchange (ETDEWEB)

    O' Grady, J; Schwender, J; Shachar-Hill, Y; Morgan, JA

    2012-03-26

    For the past decade, flux maps have provided researchers with an in-depth perspective on plant metabolism. As a rapidly developing field, significant headway has been made recently in computation, experimentation, and overall understanding of metabolic flux analysis. These advances are particularly applicable to the study of plant metabolism. New dynamic computational methods such as non-stationary metabolic flux analysis are finding their place in the toolbox of metabolic engineering, allowing more organisms to be studied and decreasing the time necessary for experimentation, thereby opening new avenues by which to explore the vast diversity of plant metabolism. Also, improved methods of metabolite detection and measurement have been developed, enabling increasingly greater resolution of flux measurements and the analysis of a greater number of the multitude of plant metabolic pathways. Methods to deconvolute organelle-specific metabolism are employed with increasing effectiveness, elucidating the compartmental specificity inherent in plant metabolism. Advances in metabolite measurements have also enabled new types of experiments, such as the calculation of metabolic fluxes based on (CO2)-C-13 dynamic labelling data, and will continue to direct plant metabolic engineering. Newly calculated metabolic flux maps reveal surprising and useful information about plant metabolism, guiding future genetic engineering of crops to higher yields. Due to the significant level of complexity in plants, these methods in combination with other systems biology measurements are necessary to guide plant metabolic engineering in the future.

  11. Ensemble Kinetic Modeling of Metabolic Networks from Dynamic Metabolic Profiles

    Directory of Open Access Journals (Sweden)

    Gengjie Jia

    2012-11-01

    Full Text Available Kinetic modeling of metabolic pathways has important applications in metabolic engineering, but significant challenges still remain. The difficulties faced vary from finding best-fit parameters in a highly multidimensional search space to incomplete parameter identifiability. To meet some of these challenges, an ensemble modeling method is developed for characterizing a subset of kinetic parameters that give statistically equivalent goodness-of-fit to time series concentration data. The method is based on the incremental identification approach, where the parameter estimation is done in a step-wise manner. Numerical efficacy is achieved by reducing the dimensionality of parameter space and using efficient random parameter exploration algorithms. The shift toward using model ensembles, instead of the traditional “best-fit” models, is necessary to directly account for model uncertainty during the application of such models. The performance of the ensemble modeling approach has been demonstrated in the modeling of a generic branched pathway and the trehalose pathway in Saccharomyces cerevisiae using generalized mass action (GMA kinetics.

  12. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Jagannathan, Naranamangalam R; Sharma, Uma

    2017-06-07

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using ¹H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  13. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Naranamangalam R. Jagannathan

    2017-06-01

    Full Text Available Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  14. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Jagannathan, Naranamangalam R.; Sharma, Uma

    2017-01-01

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods. PMID:28590405

  15. Anaerobic metabolism in Brassica seedlings

    Science.gov (United States)

    Park, Myoung-Ryoul; Hasenstein, Karl H.

    Germination typically depends on oxidative respiration. The lack of convection under space conditions may create hypoxic or conditions during seed germination. We investigated the effect of reduced oxygen on seed germination and metabolism to understand how metabolic constraints affect seed growth and responsiveness to reorientation. Germination was completely inhibited when seeds were imbibed in the absence of oxygen; germination occurred at 5% oxygen and higher levels. Adding oxygen after 72 h resulted in immediate germination (protrusion of the radicle). Hypoxia typically activates alcohol dehydrogenase (ADH, EC 1.1.1.1) and lactate dehydrogenase (LDH, EC 1.1.1.27) which produce ethanol and/or L-lactate, respectively. We report on the expression of ADH1 and LDH1, and changes in total soluble sugars, starch, pH, and L-lactate in seedlings grown at 28°C in 0, 2.5, 5, 10% and ambient (21%) oxygen conditions as controls. The highest consumption (lowest level) of sugars was seen at 0% oxygen but the lowest level of starch occurred 24 h after imbibition under ambient condition. Expression levels of ADH1 in ambient oxygen condition increased within 24 h but increased threefold under hypoxic conditions; LDH1 increased up to 8-fold under hypoxia compared to controls but ADH1 and LDH1 were less expressed as the oxygen levels increased. The intracellular pH of seeds decreased as the content of L-lactate increased for all oxygen concentrations. These results indicate that germination of Brassica is sensitive to oxygen levels and that oxygen availability during germination is an important factor for metabolic activities. (Supported by NASA grant NNX10AP91G)

  16. Corticosterone metabolism and membrane transport.

    Science.gov (United States)

    Sabatini, S; Hartsell, A; Meyer, M; Kurtzman, N A; Hierholzer, K

    1993-01-01

    The mammalian kidney metabolizes virtually all of the steroid hormones. Corticosterone receptors have been found in the cortical collecting tubule, and at least four metabolites of the hormone have been identified in rat renal tissue and urine. The biologic activity of these metabolites is not completely known. In this study, we examined the functional effects of three of the metabolites of corticosterone on membrane transport in toad and turtle bladders; we also analyzed the oxidoreductase pathways for corticosterone metabolism. In the toad bladder, maximal water flow (vasopressin- and cyclic AMP-stimulated) was unaffected by corticosterone, 11-dehydro-20-dihydrocorticosterone (metabolite I) and 11-dehydrocorticosterone (metabolite IV); maximal water flow was significantly inhibited by 20-dihydrocorticosterone (metabolite II). Sodium transport in the toad bladder was stimulated by corticosterone, 11-dehydrocorticosterone and 20-dihydrocorticosterone. Analysis of the oxidoreductase pathways in this tissue revealed that most of the corticosterone was oxidized to 11-dehydrocorticosterone, a biologically active compound; 11-dehydrocorticosterone was further metabolized to 11-dehydro-20-dihydrocorticosterone, a biologically inactive compound. Only 6% of the parent compound was converted to 20-dihydrocorticosterone. In the turtle bladder, none of the metabolites tested altered hydrogen ion secretion over the time period studied; no significant biotransformation of corticosterone occurred in this tissue. As the metabolites of corticosterone found in toad bladder are the same as those identified in mammalian tissues, our studies suggest that some of them may be important modulators of sodium and water transport in the distal nephron. Our data further suggest that these compounds are likely not involved in the regulation of urinary acidification.

  17. CACODYLIC ACID (DMAV): METABOLISM AND ...

    Science.gov (United States)

    The cacodylic acid (DMAV) issue paper discusses the metabolism and pharmacokinetics of the various arsenical chemicals; evaluates the appropriate dataset to quantify the potential cancer risk to the organic arsenical herbicides; provides an evaluation of the mode of carcinogenic action (MOA) for DMAV including a consideration of the key events for bladder tumor formation in rats, other potential modes of action; and also considers the human relevance of the proposed animal MOA. As part of tolerance reassessment under the Food Quality Protection Act for the August 3, 2006 deadline, the hazard of cacodylic acid is being reassessed.

  18. Metabolic bone disease of prematurity

    Directory of Open Access Journals (Sweden)

    Stacy E. Rustico, MD

    2014-09-01

    Full Text Available Metabolic bone disease (MBD of prematurity remains a significant problem for preterm, chronically ill neonates. The definition and recommendations for screening and treatment of MBD vary in the literature. A recent American Academy of Pediatrics Consensus Statement may help close the gap in institutional variation, but evidence based practice guidelines remain obscure due to lack of normative data and clinical trials for preterm infants. This review highlights mineral homeostasis physiology, current recommendations in screening and monitoring, prevention and treatment strategies, and an added perspective of a bone health team serving a high volume referral neonatal intensive care center.

  19. Migraine: A disorder of metabolism?

    Science.gov (United States)

    Kokavec, Anna

    2016-12-01

    The treatment and prevention of migraine within the last decade has become largely pharmacological. While there is little doubt that the advent of drugs (e.g. triptans) has helped many migraine sufferers to lead a normal life, there is still little knowledge with respect to the factors responsible for precipitating a migraine attack. Evidence from biochemical and behavioural studies from a number of disciplines is integrated to put forward the proposal that migraine is part of a cascade of events, which together act to protect the organism when confronted by a metabolic challenge. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  20. Microbiological and geochemical dynamics in simulated-heap leaching of a polymetallic sulfide ore.

    Science.gov (United States)

    Wakeman, Kathryn; Auvinen, Hannele; Johnson, D Barrie

    2008-11-01

    The evolution of microbial populations involved in simulated-heap leaching of a polymetallic black schist sulfide ore (from the recently-commissioned Talvivaara mine, Finland) was monitored in aerated packed bed column reactors over a period of 40 weeks. The influence of ore particle size (2-6.5 mm and 6.5-12 mm) on changes in composition of the bioleaching microflora and mineral leaching dynamics in columns was investigated and compared to fine-grain (leached within 6 weeks, though relatively little of the copper present in the ore was solubilised. The microbial consortium that emerged from the original inoculum was relatively simple in shake flasks, and was dominated by the iron-oxidizing autotroph Leptospirillum ferriphilum, with smaller numbers of Acidimicrobium ferrooxidans, Acidithiobacillus caldus and Leptospirillum ferrooxidans. Both metal recovery and (for the most part) total numbers of prokaryotes were greater in the column reactor containing the medium-grain than that containing the coarse-grain ore. The bioleaching communities in the columns displayed temporal changes in composition and differed radically from those in shake flask cultures. While iron-oxidizing chemoautotrophic bacteria were always the most numerically dominant bacteria in the medium-grain column bioreactor, there were major shifts in the most abundant species present, with the type strain of Acidithiobacillus ferrooxidans dominating in the early phase of the experiment and other bacteria (At. ferrooxidans NO37 and L. ferriphilum) dominating from week 4 to week 40. With the coarse-grain column bioreactor, similar transitions in populations of iron-oxidizing chemoautotrophs were observed, though heterotrophic acidophiles were often the most abundant bacteria found in mineral leach liquors. Four bacteria not included in the mixed culture used to inoculate the columns were detected by biomolecular techniques and three of these (all Alicyclobacillus-like Firmicutes) were isolated as pure

  1. Chinese Herbs Interfering with Cancer Reprogramming Metabolism

    Directory of Open Access Journals (Sweden)

    Zhangfeng Zhong

    2016-01-01

    Full Text Available Emerging evidence promotes a reassessment of metabolic reprogramming regulation in cancer research. Although there exists a long history of Chinese herbs applied in cancer treatment, few reports have addressed the effects of Chinese herbal components on metabolic reprogramming, which is a central cancer hallmark involved in the slowing or prevention of chemoresistance in cancer cells. In this review, we have focused on four core elements altered by metabolic reprogramming in cancer cells. These include glucose transport, glycolysis, mitochondrial oxidative phosphorylation, and fatty acid synthesis. With this focus, we have summarized recent advances in metabolic reprogramming of cancer cells in response to specific Chinese herbal components. We propose that exploring Chinese herbal interference in cancer metabolic reprogramming might identify new therapeutic targets for cancer and more ways in which to approach metabolism-related diseases.

  2. ER Stress and Lipid Metabolism in Adipocytes

    Directory of Open Access Journals (Sweden)

    Beth S. Zha

    2012-01-01

    Full Text Available The role of endoplasmic reticulum (ER stress is a rapidly emerging field of interest in the pathogenesis of metabolic diseases. Recent studies have shown that chronic activation of ER stress is closely linked to dysregulation of lipid metabolism in several metabolically important cells including hepatocytes, macrophages, β-cells, and adipocytes. Adipocytes are one of the major cell types involved in the pathogenesis of the metabolic syndrome. Recent advances in dissecting the cellular and molecular mechanisms involved in the regulation of adipogenesis and lipid metabolism indicate that activation of ER stress plays a central role in regulating adipocyte function. In this paper, we discuss the current understanding of the potential role of ER stress in lipid metabolism in adipocytes. In addition, we touch upon the interaction of ER stress and autophagy as well as inflammation. Inhibition of ER stress has the potential of decreasing the pathology in adipose tissue that is seen with energy overbalance.

  3. Metabolic pathways regulated by p63.

    Science.gov (United States)

    Candi, Eleonora; Smirnov, Artem; Panatta, Emanuele; Lena, Anna Maria; Novelli, Flavia; Mancini, Mara; Viticchiè, Giuditta; Piro, Maria Cristina; Di Daniele, Nicola; Annicchiarico-Petruzzelli, Margherita; Melino, Gerry

    2017-01-15

    The transcription factor p63 belongs to the p53-family and is a master regulator of proliferative potential, lineage specification, and differentiation in epithelia during development and tissue homeostasis. In cancer, p63 contribution is isoform-specific, with both oncogenic and tumour suppressive roles attributed, for ΔNp63 and TAp63, respectively. Recently, p53 and TAp73, in line with other tumour suppressor genes, have emerged as important regulators of energy metabolism and metabolic reprogramming in cancer. To date, p63 contributions in controlling energy metabolism have been partially investigated; given the extensive interaction of the p53 family members, these studies have potential implications in tumour cells for metabolic reprogramming. Here, we review the role of p63 isoforms, TAp63 and ΔNp63, in controlling cell metabolism, focusing on their specific metabolic target genes and their physiological/functional context of action. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Metabolic regulation of immune responses: therapeutic opportunities.

    Science.gov (United States)

    Assmann, Nadine; Finlay, David K

    2016-06-01

    Immune cell metabolism is dynamically regulated in parallel with the substantial changes in cellular function that accompany immune cell activation. While these changes in metabolism are important for facilitating the increased energetic and biosynthetic demands of activated cells, immune cell metabolism also has direct roles in controlling the functions of immune cells and shaping the immune response. A theme is emerging wherein nutrients, metabolic enzymes, and metabolites can act as an extension of the established immune signal transduction pathways, thereby adding an extra layer of complexity to the regulation of immunity. This Review will outline the metabolic configurations adopted by different immune cell subsets, describe the emerging roles for metabolic enzymes and metabolites in the control of immune cell function, and discuss the therapeutic implications of this emerging immune regulatory axis.

  5. Metabolic Alterations in Renal and Prostate Cancer.

    Science.gov (United States)

    Ciccarese, Chiara; Santoni, Matteo; Massari, Francesco; Modena, Alessandra; Piva, Francesco; Conti, Alessandro; Mazzucchelli, Roberta; Cheng, Liang; Lopez-Beltran, Antonio; Scarpelli, Marina; Tortora, Giampaolo; Montironi, Rodolfo

    2016-01-01

    Cancer metabolism is emerging as a promising research area in genitourinary tumors. Both renal cell carcinoma (RCC) and prostate cancer (PCa) cells exhibit marked alterations of their metabolism. These changes include increased aerobic glycolysis (the Warburg effect), increased protein and DNA synthesis and de novo fatty acid (FA) synthesis. Understanding the molecular mechanisms underlying such alterations will represent a major step forward in cancer research. Indeed, reprogramming cancer cell energy metabolism represents a promising hallmark of cancer and may pave the way for novel personalized approaches. PubMed databases were searched for articles published about cancer metabolism in genitourinary tumors. This review is focused on the metabolic alterations that occur in RCC and PCa and describes the mechanisms underlying such metabolic changes.

  6. The plasticity of cyanobacterial carbon metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Wei; Cano, Melissa; Wang, Bo; Douchi, Damien; Yu, Jianping

    2017-12-01

    This opinion article aims to raise awareness of a fundamental issue which governs sustainable production of biofuels and bio-chemicals from photosynthetic cyanobacteria. Discussed is the plasticity of carbon metabolism, by which the cyanobacterial cells flexibly distribute intracellular carbon fluxes towards target products and adapt to environmental/genetic alterations. This intrinsic feature in cyanobacterial metabolism is being understood through recent identification of new biochemical reactions and engineering on low-throughput pathways. We focus our discussion on new insights into the nature of metabolic plasticity in cyanobacteria and its impact on hydrocarbons (e.g. ethylene and isoprene) production. We discuss approaches that need to be developed to rationally rewire photosynthetic carbon fluxes throughout primary metabolism. We outline open questions about the regulatory mechanisms of the metabolic network that remain to be answered, which might shed light on photosynthetic carbon metabolism and help optimize design principles in order to improve the production of fuels and chemicals in cyanobacteria.

  7. Is osteoarthritis a metabolic disorder?

    Science.gov (United States)

    Kluzek, S; Newton, J L; Arden, N K

    2015-09-01

    Obesity is associated with an increased risk of developing osteoarthritis (OA), even in non-weight bearing joints. High levels of adipose tissue-associated inflammation may explain this association. Published evidence looking at the associations between components of Metabolic Syndrome (MetS) and knee, hip or hand OA and the higher mortality described with knee OA. Development of MetS and OA shares a relationship with adipose tissue-associated inflammation. This review supports this inflammatory pathway being part of the shared mechanism behind obesity as a risk factor for OA and the recently described OA-associated increased mortality. In an era of an obesity epidemic, this review identifies a need for well-designed cohort studies assessing early metabolic changes in populations at high risk of OA and MetS, and to identify risk factors for increased mortality in patients with OA. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Metabolic Causes of Epileptic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Joe Yuezhou Yu

    2013-01-01

    Full Text Available Epileptic encephalopathy can be induced by inborn metabolic defects that may be rare individually but in aggregate represent a substantial clinical portion of child neurology. These may present with various epilepsy phenotypes including refractory neonatal seizures, early myoclonic encephalopathy, early infantile epileptic encephalopathy, infantile spasms, and generalized epilepsies which in particular include myoclonic seizures. There are varying degrees of treatability, but the outcome if untreated can often be catastrophic. The importance of early recognition cannot be overemphasized. This paper provides an overview of inborn metabolic errors associated with persistent brain disturbances due to highly active clinical or electrographic ictal activity. Selected diseases are organized by the defective molecule or mechanism and categorized as small molecule disorders (involving amino and organic acids, fatty acids, neurotransmitters, urea cycle, vitamers and cofactors, and mitochondria and large molecule disorders (including lysosomal storage disorders, peroxisomal disorders, glycosylation disorders, and leukodystrophies. Details including key clinical features, salient electrophysiological and neuroradiological findings, biochemical findings, and treatment options are summarized for prominent disorders in each category.

  9. Obesity: the new metabolic frontier

    Directory of Open Access Journals (Sweden)

    D.K. Yokaichiya

    2004-05-01

    Full Text Available Working on active learning strategies for web based courses, the Biochemical Education Research groupfrom USP and Unicamp;s departments of Biochemistry has developed the educational software Obesity:the new metabolic frontier. The software was designed to be used as a major reference to study thissubject on 2003 Biochemistry of Nutrition course, and was based on the most recent publications aboutobesity, specially concerning the leptin role in this metabolic disturb. The most relevant characteristicof this software is the use of animated models to represent the cellular response and the presentationof many other mechanisms involved in obesity. We also intended to focus the relationship betweenleptin and other mechanisms that lead to obesity. The teaching strategy consisted in providing thestudents with the software and a text about Obesity. After few days, they should discuss the topic ina two-hour synchronous discussions chat-rooms (specially designed for this purpose, with a TeachingAssistant;s (TA help. After the discussion, the students were asked to answer an evaluation surveyabout the activity and the software ecience to the learning process. The TAs were asked to evaluatethe software as a tool to help in teaching process. In the following week the students had to go backto the chat-rooms for an online synchronous test. The results of this experience (students and TAssatisfaction were very clear and stimulated us to go on with software development and to improvethe use of this kind of educational tool in Biochemistry classes.

  10. Simulating Metabolism with Statistical Thermodynamics

    Science.gov (United States)

    Cannon, William R.

    2014-01-01

    New methods are needed for large scale modeling of metabolism that predict metabolite levels and characterize the thermodynamics of individual reactions and pathways. Current approaches use either kinetic simulations, which are difficult to extend to large networks of reactions because of the need for rate constants, or flux-based methods, which have a large number of feasible solutions because they are unconstrained by the law of mass action. This report presents an alternative modeling approach based on statistical thermodynamics. The principles of this approach are demonstrated using a simple set of coupled reactions, and then the system is characterized with respect to the changes in energy, entropy, free energy, and entropy production. Finally, the physical and biochemical insights that this approach can provide for metabolism are demonstrated by application to the tricarboxylic acid (TCA) cycle of Escherichia coli. The reaction and pathway thermodynamics are evaluated and predictions are made regarding changes in concentration of TCA cycle intermediates due to 10- and 100-fold changes in the ratio of NAD+:NADH concentrations. Finally, the assumptions and caveats regarding the use of statistical thermodynamics to model non-equilibrium reactions are discussed. PMID:25089525

  11. Metabolic syndrome and major depression.

    Science.gov (United States)

    Marazziti, Donatella; Rutigliano, Grazia; Baroni, Stefano; Landi, Paola; Dell'Osso, Liliana

    2014-08-01

    Major depression is associated with a 4-fold increased risk for premature death, largely accounted by cardiovascular disease (CVD). The relationship between depression and CVD is thought to be mediated by the so-called metabolic syndrome (MeS). Epidemiological studies have consistently demonstrated a co-occurrence of depression with MeS components, ie, visceral obesity, dyslipidemia, insulin resistance, and hypertension. Although the exact mechanisms linking MeS to depression are unclear, different hypotheses have been put forward. On the one hand, MeS could be the hallmark of the unhealthy lifestyle habits of depressed patients. On the other, MeS and depression might share common alterations of the stress system, including the hypothalamus-pituitary-adrenal (HPA) axis, the autonomic nervous system, the immune system, and platelet and endothelial function. Both the conditions induce a low grade chronic inflammatory state that, in turn, leads to increased oxidative and nitrosative (O&NS) damage of neurons, pancreatic cells, and endothelium. Recently, neurobiological research revealed that peripheral hormones, such as leptin and ghrelin, which are classically involved in homeostatic energy balance, may play a role in mood regulation. Metabolic risk should be routinely assessed in depressed patients and taken into account in therapeutic decisions. Alternative targets should be considered for innovative antidepressant agents, including cytokines and their receptors, intracellular inflammatory mediators, glucocorticoids receptors, O&NS pathways, and peripheral mediators.

  12. Simulating metabolism with statistical thermodynamics.

    Science.gov (United States)

    Cannon, William R

    2014-01-01

    New methods are needed for large scale modeling of metabolism that predict metabolite levels and characterize the thermodynamics of individual reactions and pathways. Current approaches use either kinetic simulations, which are difficult to extend to large networks of reactions because of the need for rate constants, or flux-based methods, which have a large number of feasible solutions because they are unconstrained by the law of mass action. This report presents an alternative modeling approach based on statistical thermodynamics. The principles of this approach are demonstrated using a simple set of coupled reactions, and then the system is characterized with respect to the changes in energy, entropy, free energy, and entropy production. Finally, the physical and biochemical insights that this approach can provide for metabolism are demonstrated by application to the tricarboxylic acid (TCA) cycle of Escherichia coli. The reaction and pathway thermodynamics are evaluated and predictions are made regarding changes in concentration of TCA cycle intermediates due to 10- and 100-fold changes in the ratio of NAD+:NADH concentrations. Finally, the assumptions and caveats regarding the use of statistical thermodynamics to model non-equilibrium reactions are discussed.

  13. Deciphering transcriptional and metabolic networks associated with lysine metabolism during Arabidopsis seed development.

    Science.gov (United States)

    Angelovici, Ruthie; Fait, Aaron; Zhu, Xiaohong; Szymanski, Jedrzej; Feldmesser, Ester; Fernie, Alisdair R; Galili, Gad

    2009-12-01

    In order to elucidate transcriptional and metabolic networks associated with lysine (Lys) metabolism, we utilized developing Arabidopsis (Arabidopsis thaliana) seeds as a system in which Lys synthesis could be stimulated developmentally without application of chemicals and coupled this to a T-DNA insertion knockout mutation impaired in Lys catabolism. This seed-specific metabolic perturbation stimulated Lys accumulation starting from the initiation of storage reserve accumulation. Our results revealed that the response of seed metabolism to the inducible alteration of Lys metabolism was relatively minor; however, that which was observable operated in a modular manner. They also demonstrated that Lys metabolism is strongly associated with the operation of the tricarboxylic acid cycle while largely disconnected from other metabolic networks. In contrast, the inducible alteration of Lys metabolism was strongly associated with gene networks, stimulating the expression of hundreds of genes controlling anabolic processes that are associated with plant performance and vigor while suppressing a small number of genes associated with plant stress interactions. The most pronounced effect of the developmentally inducible alteration of Lys metabolism was an induction of expression of a large set of genes encoding ribosomal proteins as well as genes encoding translation initiation and elongation factors, all of which are associated with protein synthesis. With respect to metabolic regulation, the inducible alteration of Lys metabolism was primarily associated with altered expression of genes belonging to networks of amino acids and sugar metabolism. The combined data are discussed within the context of network interactions both between and within metabolic and transcriptional control systems.

  14. Fifteen years experience: Egyptian metabolic lab

    Directory of Open Access Journals (Sweden)

    Ekram M. Fateen

    2014-10-01

    Conclusion: This study illustrates the experience of the reference metabolic lab in Egypt over 15 years. The lab began metabolic disorder screening by using simple diagnostic techniques like thin layer chromatography and colored tests in urine which by time updated and upgraded the methods to diagnose a wide range of disorders. This study shows the most common diagnosed inherited inborn errors of metabolism among the Egyptian population.

  15. Predicting drug metabolism: Concepts and challenges

    OpenAIRE

    Testa, B; Balmat, A.-L; Long, Anthony

    2017-01-01

    The paper begins with a discussion of the needs and goals of metabolic predictions in early drug research. Major difficulties toward this objective are examined, mainly the various substrate and product selectivities characteristic of drug metabolism. In a second part, we classify and summarize the major in silico methods used to predict drug metabolism. A discrimination is thus made between "local ”and "global ”systems. In the last part of the paper, the program METEOR is presented and evalu...

  16. Neuroinflammation in Lyme neuroborreliosis affects amyloid metabolism

    OpenAIRE

    Anckarsäter Henrik; Blennow Kaj; Bremell Daniel; Anckarsäter Rolf; Mattsson Niklas; Zetterberg Henrik; Hagberg Lars

    2010-01-01

    Abstract Background The metabolism of amyloid precursor protein (APP) and β-amyloid (Aβ) is widely studied in Alzheimer's disease, where Aβ deposition and plaque development are essential components of the pathogenesis. However, the physiological role of amyloid in the adult nervous system remains largely unknown. We have previously found altered cerebral amyloid metabolism in other neuroinflammatory conditions. To further elucidate this, we investigated amyloid metabolism in patients with Ly...

  17. Toxic metabolic syndrome associated with HAART

    DEFF Research Database (Denmark)

    Haugaard, Steen B

    2006-01-01

    (HAART) may encounter the HIV-associated lipodystrophy syndrome (HALS), which attenuates patient compliance to this treatment. HALS is characterised by impaired glucose and lipid metabolism and other risk factors for cardiovascular disease. This review depicts the metabolic abnormalities associated...... with HAART by describing the key cell and organ systems that are involved, emphasising the role of insulin resistance. An opinion on the remedies available to treat the metabolic abnormalities and phenotype of HALS is provided....

  18. Metabolic syndrome and insulin resistance in migraine

    OpenAIRE

    Bhoi, Sanjeev K.; Kalita, Jayantee; Misra, Usha K.

    2012-01-01

    Metabolic syndrome is associated with migraine but there is no study comparing the characteristics of migraine with and without metabolic syndrome from Southeast Asia. This study was therefore undertaken to compare the clinical characteristics of migraine in patients with and without metabolic syndrome and insulin resistance. 135 consecutive patients with migraine diagnosed on the basis of International Headache Society criteria were subjected to clinical evaluation as per fixed protocol. Hea...

  19. Scaling of Metabolic Scaling within Physical Limits

    Directory of Open Access Journals (Sweden)

    Douglas S. Glazier

    2014-10-01

    Full Text Available Both the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypothesis (MLBH provides a useful conceptual framework for explaining and predicting much, but not all of this variation. This hypothesis is based on three major assumptions: (1 various processes related to body volume and surface area exert state-dependent effects on the scaling slope for metabolic rate in relation to body mass; (2 the elevation and slope of metabolic scaling relationships are linked; and (3 both intrinsic (anatomical, biochemical and physiological and extrinsic (ecological factors can affect metabolic scaling. According to the MLBH, the diversity of metabolic scaling relationships occurs within physical boundary limits related to body volume and surface area. Within these limits, specific metabolic scaling slopes can be predicted from the metabolic level (or scaling elevation of a species or group of species. In essence, metabolic scaling itself scales with metabolic level, which is in turn contingent on various intrinsic and extrinsic conditions operating in physiological or evolutionary time. The MLBH represents a “meta-mechanism” or collection of multiple, specific mechanisms that have contingent, state-dependent effects. As such, the MLBH is Darwinian in approach (the theory of natural selection is also meta-mechanistic, in contrast to currently influential metabolic scaling theory that is Newtonian in approach (i.e., based on unitary deterministic laws. Furthermore, the MLBH can be viewed as part of a more general theory that includes other mechanisms that may also affect metabolic scaling.

  20. Association of lipid metabolism with ovarian cancer

    OpenAIRE

    Tania, M.; Khan, M A; Y. Song

    2010-01-01

    Defects in lipid metabolism have been found to be linked to several diseases, among which atherosclerosis, hypertension, obesity, and diabetes are the most important. Although cancer is chiefly a genetic disease, dietary lipid intake and metabolism are related to some cancer risks, including the risk for ovarian cancer. Higher intake of dietary lipids, systemic lipid metabolism malfunction, and abnormal serum lipid levels are somehow related to ovarian cancer. Overexpression of some lipid met...

  1. T cell metabolism and the immune response.

    Science.gov (United States)

    Verbist, Katherine C; Wang, Ruoning; Green, Douglas R

    2012-12-01

    As T cells respond to pathogens, they must transition from a quiescent, naïve state, to a rapidly proliferating, active effector state, and back again to a quiescent state as they develop into memory cells. Such transitions place unique metabolic demands on the differentiating cells. T cells meet these demands by altering their metabolic profiles, which are, in turn, regulated by distinct signaling cascades and transcriptional programs. Here, we examine the metabolic profiles of T cells during an acute immune response and discuss the signal and transcriptional regulators of these metabolic changes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. The Reset Hypothesis: Lactation and Maternal Metabolism

    Science.gov (United States)

    Stuebe, Alison M.; Rich-Edwards, Janet W.

    2010-01-01

    For maternal metabolism, pregnancy ends not with delivery, but with weaning. In several recent epidemiological studies, authors have reported an association between duration of breast-feeding and reduced maternal risk of metabolic disease. These findings parallel data from animal models showing favorable changes in metabolism associated with lactation. During gestation, visceral fat accumulates, and insulin resistance and lipid and triglyceride levels increase. These changes appear to reverse more quickly, and more completely, with lactation. In this article, we review animal and human studies regarding the effects of lactation on adiposity, lipid, and glucose homeostasis. We hypothesize that lactation plays an important role in “resetting” maternal metabolism after pregnancy. PMID:19031350

  3. [Metabolic emergencies in critically ill cancer patients].

    Science.gov (United States)

    Namendys-Silva, Silvio A; Hernández-Garay, Marisol; García-Guillén, Francisco J; Correa-García, Paulina; Herrera Gómez, Angel; Meneses-García, Abelardo

    2013-11-01

    Severe metabolic alterations frequently occur in critically ill cancer patients; hypercalcemia, hypocalcemia, hyponatremia, tumor lysis syndrome, metabolic complications of renal failure and lactic acidosis. Cancer patients with metabolic emergencies should be treated in a medical oncology department or an intensive care unit. Most metabolic emergencies can be treated properly when they are identified early. The clinician should consider that the prognosis of critically ill cancer patients depends on their primary disease, comorbidities and organ failure. Copyright AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  4. Systems Metabolic Engineering of Escherichia coli.

    Science.gov (United States)

    Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

    2016-05-01

    Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass.

  5. Effects of introducing heterologous pathways on microbial metabolism with respect to metabolic optimality

    DEFF Research Database (Denmark)

    Kim, Hyun Uk; Kim, Byoungjin; Seung, Do Young

    2014-01-01

    Although optimality of microbial metabolism under genetic and environmental perturbations is well studied, the effects of introducing heterologous reactions on the overall metabolism are not well understood. This point is important in the field of metabolic engineering because heterologous...... reactions are more frequently introduced into various microbial hosts. The genome-scale metabolic simulations of Escherichia coli strains engineered to produce 1,4-butanediol, 1,3-propanediol, and amorphadiene suggest that microbial metabolism shows much different responses to the introduced heterologous...... as engineering targets in systems metabolic engineering strategies. To our knowledge, this study is the first attempt to quantitatively characterize microbial metabolisms with different heterologous reactions. The suggested potential reasons behind each strain’s different metabolic responses to the introduced...

  6. Metabolic modeling and analysis of the metabolic switch in Streptomyces coelicolor

    NARCIS (Netherlands)

    Alam, Mohammad T.; Merlo, Maria E.; Hodgson, David A.; Wellington, Elizabeth M. H.; Takano, Eriko; Breitling, Rainer

    2010-01-01

    Background: The transition from exponential to stationary phase in Streptomyces coelicolor is accompanied by a major metabolic switch and results in a strong activation of secondary metabolism. Here we have explored the underlying reorganization of the metabolome by combining computational

  7. Aerobic exercise training induces metabolic benefits in rats with metabolic syndrome independent of dietary changes

    National Research Council Canada - National Science Library

    Caponi, Paula Wesendonck; Lehnen, Alexandre Machado; Pinto, Graziela Hünning; Borges, Júlia; Markoski, Melissa; Machado, Ubiratan F; Schaan, Beatriz D'Agord

    2013-01-01

    We evaluated the effects of aerobic exercise training without dietary changes on cardiovascular and metabolic variables and on the expression of glucose transporter Type 4 in rats with metabolic syndrome...

  8. A guide to integrating transcriptional regulatory and metabolic networks using PROM (probabilistic regulation of metabolism).

    Science.gov (United States)

    Simeonidis, Evangelos; Chandrasekaran, Sriram; Price, Nathan D

    2013-01-01

    The integration of transcriptional regulatory and metabolic networks is a crucial step in the process of predicting metabolic behaviors that emerge from either genetic or environmental changes. Here, we present a guide to PROM (probabilistic regulation of metabolism), an automated method for the construction and simulation of integrated metabolic and transcriptional regulatory networks that enables large-scale phenotypic predictions for a wide range of model organisms.

  9. Compare the resting metabolic rate status in the healthy metabolically obese with the unhealthy metabolically obese participants

    Directory of Open Access Journals (Sweden)

    Banafshe Hosseini

    2016-12-01

    Conclusion: In this study we did not observe any major effects of RMR on metabolic health criteria except for the HOMA. Further studies are needed to investigate the effects of RMR on glucose abnormalities that may lead to modify cardio-metabolic criteria.

  10. Drug discovery strategies in the field of tumor energy metabolism: Limitations by metabolic flexibility and metabolic resistance to chemotherapy.

    Science.gov (United States)

    Amoedo, N D; Obre, E; Rossignol, R

    2017-08-01

    The search for new drugs capable of blocking the metabolic vulnerabilities of human tumors has now entered the clinical evaluation stage, but several projects already failed in phase I or phase II. In particular, very promising in vitro studies could not be translated in vivo at preclinical stage and beyond. This was the case for most glycolysis inhibitors that demonstrated systemic toxicity. A more recent example is the inhibition of glutamine catabolism in lung adenocarcinoma that failed in vivo despite a strong addiction of several cancer cell lines to glutamine in vitro. Such contradictory findings raised several questions concerning the optimization of drug discovery strategies in the field of cancer metabolism. For instance, the cell culture models in 2D or 3D might already show strong limitations to mimic the tumor micro- and macro-environment. The microenvironment of tumors is composed of cancer cells of variegated metabolic profiles, supporting local metabolic exchanges and symbiosis, but also of immune cells and stroma that further interact with and reshape cancer cell metabolism. The macroenvironment includes the different tissues of the organism, capable of exchanging signals and fueling the tumor 'a distance'. Moreover, most metabolic targets were identified from their increased expression in tumor transcriptomic studies, or from targeted analyses looking at the metabolic impact of particular oncogenes or tumor suppressors on selected metabolic pathways. Still, very few targets were identified from in vivo analyses of tumor metabolism in patients because such studies are difficult and adequate imaging methods are only currently being developed for that purpose. For instance, perfusion of patients with [(13)C]-glucose allows deciphering the metabolomics of tumors and opens a new area in the search for effective targets. Metabolic imaging with positron emission tomography and other techniques that do not involve [(13)C] can also be used to evaluate tumor

  11. Relationship Between Metabolic Syndrome and Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Serkan Bas

    2016-07-01

    Full Text Available Aim: Metabolic syndrome has gained increased attention in the last century after researchers identified its important role in cardiovascular mortality and morbidity in developed countries. Despite limited research into the relationship between metabolic syndrome and prostate cancer (PCa, the precise relationship has not been elucidated due to lack of research into the specific factors associated with PCa. To fill this research gap, we evaluated the incidence of PCa in patients with metabolic syndrome and the relationship between metabolic syndrome and the parameters of PCa. Material and Method: We retrospectively evaluated the biochemical analyses of the serum parameters and pathological reports of 102 PCa patients diagnosed by transrectal ultrasound. After determining the incidence of metabolic syndrome in patients with PCa, we divided the patients into two groups, those with and without a diagnosis of metabolic syndrome. We then compared the serum PSA level, age, total prostate volume, Gleason score, triglyceride (TG level, high-density lipoprotein cholesterol level (HDL-C, blood pressure, and fasting glucose level of the two groups. Results: We included 102 patients with a diagnosis of prostate cancer in the present study. Among the 102 patients, 18 (17.6% were diagnosed with metabolic syndrome. While the PSA levels of the PCa patients were found to be significantly lower in those with metabolic syndrome compared to those without metabolic syndrome (P=0.04, no difference was found between the groups regarding the other components of PCa (P>0.05. Discussion: Serum PSA level was found to be significantly lower in those with metabolic syndrome. This result leads us to consider whether prostate biopsy should be performed in patients with metabolic syndrome who have lower PSA levels than the levels currently specified for biopsy. Further research into the parameters of PCa needs to be conducted to confirm our findings.

  12. A compendium of inborn errors of metabolism mapped onto the human metabolic network.

    Science.gov (United States)

    Sahoo, Swagatika; Franzson, Leifur; Jonsson, Jon J; Thiele, Ines

    2012-10-01

    Inborn errors of metabolism (IEMs) are hereditary metabolic defects, which are encountered in almost all major metabolic pathways occurring in man. Many IEMs are screened for in neonates through metabolomic analysis of dried blood spot samples. To enable the mapping of these metabolomic data onto the published human metabolic reconstruction, we added missing reactions and pathways involved in acylcarnitine (AC) and fatty acid oxidation (FAO) metabolism. Using literary data, we reconstructed an AC/FAO module consisting of 352 reactions and 139 metabolites. When this module was combined with the human metabolic reconstruction, the synthesis of 39 acylcarnitines and 22 amino acids, which are routinely measured, was captured and 235 distinct IEMs could be mapped. We collected phenotypic and clinical features for each IEM enabling comprehensive classification. We found that carbohydrate, amino acid, and lipid metabolism were most affected by the IEMs, while the brain was the most commonly affected organ. Furthermore, we analyzed the IEMs in the context of metabolic network topology to gain insight into common features between metabolically connected IEMs. While many known examples were identified, we discovered some surprising IEM pairs that shared reactions as well as clinical features but not necessarily causal genes. Moreover, we could also re-confirm that acetyl-CoA acts as a central metabolite. This network based analysis leads to further insight of hot spots in human metabolism with respect to IEMs. The presented comprehensive knowledge base of IEMs will provide a valuable tool in studying metabolic changes involved in inherited metabolic diseases.

  13. Precision metabolic engineering: The design of responsive, selective, and controllable metabolic systems.

    Science.gov (United States)

    McNerney, Monica P; Watstein, Daniel M; Styczynski, Mark P

    2015-09-01

    Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed "precision metabolic engineering," involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  14. Retinoids: Potent regulators of metabolism.

    Science.gov (United States)

    Brun, Pierre-Jacques; Yang, Kryscilla Jian Zhang; Lee, Seung-Ah; Yuen, Jason J; Blaner, William S

    2013-01-01

    Retinoids (vitamin A and its analogs) are highly potent regulators of cell differentiation, cell proliferation, and apoptosis. Because of these activities, retinoids have been most extensively studied in the contexts of embryonic development and of proliferative diseases, especially cancer and skin disease. Recently, there has been considerable new research interest focused on gaining understanding of the roles that retinoids and/or retinoid-related proteins may have in the development of metabolic diseases, primarily obesity, diabetes, and dyslipidemia. This review will summarize recent advances that have been made in these areas, focusing on the role of retinoids in modulating adipogenesis, the roles of retinoids and retinoid-related proteins as signaling molecules linking obesity with the development of type II diabetes, the roles of retinoids in pancreatic β-cell biology/insulin secretion, and the actions of retinoids in hepatic steatosis. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

  15. Metabolic syndrome in South Asians

    Directory of Open Access Journals (Sweden)

    Kaushik Pandit

    2012-01-01

    Full Text Available South Asia is home to one of the largest population of people with metabolic syndrome (MetS. The prevalence of MetS in South Asians varies according to region, extent of urbanization, lifestyle patterns, and socioeconomic/cultural factors. Recent data show that about one-third of the urban population in large cities in India has the MetS. All classical risk factors comprising the MetS are prevalent in Asian Indians residing in India. The higher risk in this ethnic population necessitated a lowering of the cut-off values of the risk factors to identify and intervene for the MetS to prevent diabetes and cardiovascular disease. Some pharmacological and nonpharmacological interventions are underway in MetS to assess the efficacy in preventing the diabetes and cardiovascular disease in this ethnic population.

  16. Metabolic hypothesis for human altriciality.

    Science.gov (United States)

    Dunsworth, Holly M; Warrener, Anna G; Deacon, Terrence; Ellison, Peter T; Pontzer, Herman

    2012-09-18

    The classic anthropological hypothesis known as the "obstetrical dilemma" is a well-known explanation for human altriciality, a condition that has significant implications for human social and behavioral evolution. The hypothesis holds that antagonistic selection for a large neonatal brain and a narrow, bipedal-adapted birth canal poses a problem for childbirth; the hominin "solution" is to truncate gestation, resulting in an altricial neonate. This explanation for human altriciality based on pelvic constraints persists despite data linking human life history to that of other species. Here, we present evidence that challenges the importance of pelvic morphology and mechanics in the evolution of human gestation and altriciality. Instead, our analyses suggest that limits to maternal metabolism are the primary constraints on human gestation length and fetal growth. Although pelvic remodeling and encephalization during hominin evolution contributed to the present parturitional difficulty, there is little evidence that pelvic constraints have altered the timing of birth.

  17. [Calcium metabolism after the menopause].

    Science.gov (United States)

    Kanovitch, D; Klotz, H P

    1976-02-16

    The authors recall the antagonism between estradiol and parathormone. Estradiol tends to lower serum calcium and fix calcium in the bones as shown by one of us 25 years ago. The mechanism of this action of estrogen on calcium metabolism has been determined by numerous authors but some points are still not clear, e.g. the interferences between estrogen and calcitonin. Classically, parathormone is known to increase bony reabsorption and raise serum calcium. After the menopause the gradual reduction in estradiol secretion leads to post-menopausal osteoporosis. It is better to administer estrogens prophylactically to women after the menopause provided a cervical smear and mammography have been carried out to eliminate latent carcinoma of the breast or uterine cervix.

  18. Paraneoplastic endocrine-metabolic syndromes

    Directory of Open Access Journals (Sweden)

    Marco Grandi

    2013-04-01

    Full Text Available BACKGROUND The paraneoplastic syndromes (PS are characterized by the presence of biochemical alterations, signs and symptoms expressive of cancer distance action into the patient’s organism. Sometimes these syndromes can precede the evidence of malignancy even of some years or can correspond to cancer relapse. PS, even being characterized by general symptoms (fever, anorexia, cachexia, may occur with neurological, rheumathological, osteoarticular, vascular, haematological, nephrological and endocrinological/metabolic symptoms; the latter ones are discussed in this article. AIM OF THE STUDY Here we will focus on the most common PS: paraneoplastic hypercalcemia, inappropriate secretion of antidiuretic hormone (SIADH and paraneoplastic Cushing syndrome. CONCLUSIONS Our work can be useful in the diagnosis and therapeutic management of paraneoplastic syndromes.

  19. Thyroid hormone metabolism in poultry

    Directory of Open Access Journals (Sweden)

    Darras V.M.

    2000-01-01

    Full Text Available Thyroid hormone (TH receptors preferentially bind 3.5,3'-triiodothyronine (T3. Therefore the metabolism of thyroxine (T4 secreted by the thyroid gland in peripheral tissues, resulting in the production and degradation of receptor-active T3, plays a major role in thyroid function. The most important metabolic pathway for THs is deiodination. Another important pathway is sulfation, which is a reversible pathway that has been shown to interact with TH deiodination efficiency. The enzymes catalysing TH deiodination consist of three types. Type 1 deiodinase (D1 catalyses both outer ring (ORD and inner ring deiodinalion (IRD. Type II deiodinase (D2 only catalyses ORD while type III (D3 only catalyses IRD. The three chicken deiodinase cDNAs have been cloned recently. These enzymes all belong to the family of selenoproteins. Ontogenetic studies show that the availability of deiodinases is regulated in a tissue specific and developmental stage dependent way. Characteristic for the chicken is the presence of very high levels off, inactivating D3 enzyme in the embryonic liver. Hepatic D3 is subject to acute regulation in a number of situations. Both growth hormone and glucocorticoid injection rapidly decrease hepatic D3 levels, hereby increasing plasma T3 without affecting hepatic D1 levels. The inhibition of D3 seems to be regulated mainly at the level of D3 gene transcription. The effect of growth hormone on D3 expression persists throughout life, while glucocorticoids start to inhibit hepatic D1 expression in posthatch chickens. Food restriction in growing chickens increases hepatic D3 levels. This contributes to the decrease in plasma T3 necessary to reduce energy loss. Refeeding restores hepatic D3 and plasma T3 to control levels within a few hours. It can be concluded that the tissue and time dependent regulation of the balance between TH activating and inactivating enzymes plays an essential role in the control of local T3 availability and hence in

  20. Epilepsy in inherited metabolic disorders.

    Science.gov (United States)

    Pascual, Juan M; Campistol, Jaume; Gil-Nagel, Antonio

    2008-11-01

    The study of neurometabolic diseases is still in a prolonged preliminary stage. The catalogue of these diseases continues to grow; some known clinical syndromes have been subdivided into a number of variants once the genes that cause them have been identified, and at the same time new metabolic disorders have been discovered that aggravate or contribute to forms of epilepsy not previously classified as cerebral metabolic disorders. This review presents the basic principles underlying the recognition and treatment of epilepsy caused by neurometabolic diseases. These disorders are divided (purely for the sake of convenience) into epilepsy presenting in newborn infants, children, and adolescents and adults, recognizing that there is a significant degree of overlap between these chronological stages. Current analytical methods and therapeutic approaches are summarized both from a general point of view and within the context of each clinical syndrome, acknowledging that each patient presents specific peculiarities and that, in general, antiepileptic drugs provide few benefits compared with more specific types of therapy (eg, special diets or vitamins) when indicated. We also include therapeutic recommendations and a general approach to fulminant epilepsies of neurometabolic origin, emphasizing the importance of identifying all of the proband's relatives who may be potential carriers of a genetic disorder during the diagnostic and genetic counselling process. Particular emphasis is placed on disorders for which there is curative treatment and on the importance of follow-up by expert professionals. It is expected that in a few years' time it will be possible to know the metabolomic profile of these diseases (possibly by non-invasive methods), thus facilitating accurate diagnosis and making it possible to establish the response to treatment and to identify all individuals who are carriers or remain minimally symptomatic in terms of their risk of manifesting or transmitting

  1. Genotype networks in metabolic reaction spaces

    Science.gov (United States)

    2010-01-01

    Background A metabolic genotype comprises all chemical reactions an organism can catalyze via enzymes encoded in its genome. A genotype is viable in a given environment if it is capable of producing all biomass components the organism needs to survive and reproduce. Previous work has focused on the properties of individual genotypes while little is known about how genome-scale metabolic networks with a given function can vary in their reaction content. Results We here characterize spaces of such genotypes. Specifically, we study metabolic genotypes whose phenotype is viability in minimal chemical environments that differ in their sole carbon sources. We show that regardless of the number of reactions in a metabolic genotype, the genotypes of a given phenotype typically form vast, connected, and unstructured sets -- genotype networks -- that nearly span the whole of genotype space. The robustness of metabolic phenotypes to random reaction removal in such spaces has a narrow distribution with a high mean. Different carbon sources differ in the number of metabolic genotypes in their genotype network; this number decreases as a genotype is required to be viable on increasing numbers of carbon sources, but much less than if metabolic reactions were used independently across different chemical environments. Conclusions Our work shows that phenotype-preserving genotype networks have generic organizational properties and that these properties are insensitive to the number of reactions in metabolic genotypes. PMID:20302636

  2. Household metabolism in European countries and cities

    NARCIS (Netherlands)

    Kok, R.; Falkena, H.J.; Benders, R.M.J.; Moll, H.C.; Noorman, K.J.

    2003-01-01

    The concept of household metabolism was applied to enhance the understanding of the environmental impacts of household consumption in cities during the second phase of the ToolSust project. The household metabolism in four European cities was determined in terms of total energy requirements,

  3. EAMJ Bone Metabolism April 10.indd

    African Journals Online (AJOL)

    2010-04-04

    Apr 4, 2010 ... bone metabolism and decreased bone density are inducers of the ... BONE METABOLISM IN HEALTHY AMBULATORY CONTROL PRE-MENOPAUSAL WOMEN AND IN EPILEPTICS. ON ANTI-CONVULSANT DRUGS ..... difficult to assess objectively, like diet, exercise status and co-morbidity. Also drug ...

  4. Changing industrial metabolism: methods for analysis

    NARCIS (Netherlands)

    Janssen, M.A.; van den Bergh, J.C.J.M.; van Beukering, P.J.H.; Hoekstra, R.

    2001-01-01

    Research in the field of "industrial metabolism" traditionally has been focused on measuring and describing physical flows of economic systems. The "metabolism" of economic systems, however, changes over time, and measuring material flows is insufficient to understand this process. Understanding the

  5. Engineering of sugar metabolism in Lactococcus lactis

    NARCIS (Netherlands)

    Pool, Weia Arianne

    2008-01-01

    Short English Summary Lactococcus lactis is a lactic acid bacterium used in the dairy industry. This thesis decribes the genetic engineering performed on the sugar metabolism of L. lactis. Besides our fundamental interest for sugar metabolism and its regulation in L. lactis, this project had the

  6. Correlated FLIM and PLIM for cell metabolism

    Science.gov (United States)

    Rück, A.; Breymayer, J.; Kalinina, S.

    2016-03-01

    Correlated imaging of phosphorescence and fluorescence lifetime parameters of metabolic markers is a challenge for direct investigating mechanisms related to cell metabolism and oxygen tension. A large variety of clinical phenotypes is associated with mitochondrial defects accomplished with changes in cell metabolism. In many cases the hypoxic microenvironment of cancer cells shifts metabolism from oxidative phosphorylation (OXPHOS) to anaerobic or aerobic glycolysis, a process known as "Warburg" effect. Also during stem cell differentiation a switch in cell metabolism is observed. A defective mitochondrial function associated with hypoxia has been invoked in many complex disorders such as type 2 diabetes, Alzheimers disease, cardiac ischemia/reperfusion injury, tissue inflammation and cancer. Cellular responses to oxygen tension have been studied extensively, optical imaging techniques based on time correlated single photon counting (TCSPC) to detect the underlying metabolic mechanisms are therefore of prominent interest. They offer the possibility by inspecting fluorescence decay characteristics of intrinsic coenzymes to directly image metabolic pathways. Moreover oxygen tension can be determined by considering the phosphorescence lifetime of a phosphorescent probe. The combination of both fluorescence lifetime imaging (FLIM) of coenzymes like NADH and FAD and phosphorescence lifetime (PLIM) of phosphorescent dyes could provide valuable information about correlation of metabolic pathways and oxygen tension.

  7. Textbook Errors & Misconceptions in Biology: Cell Metabolism.

    Science.gov (United States)

    Storey, Richard D.

    1991-01-01

    The idea that errors and misconceptions in biology textbooks are often slow to be discovered and corrected is discussed. Selected errors, misconceptions, and topics of confusion about cell metabolism are described. Fermentation, respiration, Krebs cycle, pentose phosphate pathway, uniformity of catabolism, and metabolic pathways as models are…

  8. African Journal of Endocrinology and Metabolism

    African Journals Online (AJOL)

    The African Journal of Endocrinology and Metabolism (AJEM) is a biomedical peer-reviewed journal with international circulation. It publishes Reports of Original Work, preferably briefly described, in the fields of endocrinology, metabolism and related subjects. Reviews are authoritative, evidence-based articles on topical ...

  9. Bone as a regulator of glucose metabolism

    NARCIS (Netherlands)

    Veldhuis-Vlug, A. G.; Fliers, E.; Bisschop, P. H.

    2013-01-01

    For a long time the only functions attributed to the skeleton were locomotion and calcium storage. Over the last decade, this view has changed. Genetic studies in mice have shown that bone metabolism is regulated by the autonomic nervous system and interacts with energy metabolism and reproduction.

  10. Knowledge representation in metabolic pathway databases

    NARCIS (Netherlands)

    Stobbe, M.D.; Jansen, G.A.; Moerland, P.D.; van Kampen, A.H.C.

    2014-01-01

    The accurate representation of all aspects of a metabolic network in a structured format, such that it can be used for a wide variety of computational analyses, is a challenge faced by a growing number of researchers. Analysis of five major metabolic pathway databases reveals that each database has

  11. Marxism, social metabolism, and ecologically unequal exchange

    OpenAIRE

    Joan Martínez Alier

    2004-01-01

    Authors working on "industrial metabolism" or "social metabolism" look at the economy in terms of flows of energy and materials. Together with the ecological economists, they see the economy as a subsystem of a larger physical system. Marx and Engels followed with a few years' delay many of the remarkable scientific and technical novelties of their time.

  12. Neuroendocrine regulation of human bone metabolism

    NARCIS (Netherlands)

    Vlug, A.G.

    2015-01-01

    The skeleton is perhaps the most multifunctional part of our body. It not only provides outer strength, a protective shell and enables locomotion, but it also hosts the bone marrow and serves many metabolic and endocrine functions. This thesis investigates two aspects of human bone metabolism,

  13. Adaptations in the energy metabolism of parasites

    NARCIS (Netherlands)

    van Grinsven, K.W.A.|info:eu-repo/dai/nl/304833436

    2009-01-01

    For this thesis fundamental research was performed on the metabolic adaptations found in parasites. Studying the adaptations in parasite metabolisms leads to a better understanding of parasite bioenergetics and can also result in the identification of new anti-parasitic drug targets. We focussed on

  14. L-Fucose metabolism in camplobacter jejuni

    Science.gov (United States)

    Campylobacter jejuni is a gastrointestinal pathogen once considered asaccharolytic, but now known to metabolize fucose. Strains with the fuc locus encode enzymes for fucose uptake and metabolism and show a competitive colonization advantage in the piglet disease model. C. jejuni NCTC11168 shows redu...

  15. Circadian rhythms in liver metabolism and disease

    Directory of Open Access Journals (Sweden)

    Jessica M. Ferrell

    2015-03-01

    Full Text Available Mounting research evidence demonstrates a significant negative impact of circadian disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidence of metabolic syndrome, and consequently result in obesity, type 2 diabetes and dyslipidemia. Here, these associations are reviewed with respect to liver metabolism and disease.

  16. Swimming Performance and Metabolism of Golden Shiners

    Science.gov (United States)

    The swimming ability and metabolism of golden shiners, Notemigonus crysoleucas, was examined using swim tunnel respirometery. The oxygen consumption and tail beat frequencies at various swimming speeds, an estimation of the standard metabolic rate, and the critical swimming speed (Ucrit) was determ...

  17. Metabolic imaging in multiple time scales.

    Science.gov (United States)

    Ramanujan, V Krishnan

    2014-03-15

    We report here a novel combination of time-resolved imaging methods for probing mitochondrial metabolism in multiple time scales at the level of single cells. By exploiting a mitochondrial membrane potential reporter fluorescence we demonstrate the single cell metabolic dynamics in time scales ranging from microseconds to seconds to minutes in response to glucose metabolism and mitochondrial perturbations in real time. Our results show that in comparison with normal human mammary epithelial cells, the breast cancer cells display significant alterations in metabolic responses at all measured time scales by single cell kinetics, fluorescence recovery after photobleaching and by scaling analysis of time-series data obtained from mitochondrial fluorescence fluctuations. Furthermore scaling analysis of time-series data in living cells with distinct mitochondrial dysfunction also revealed significant metabolic differences thereby suggesting the broader applicability (e.g. in mitochondrial myopathies and other metabolic disorders) of the proposed strategies beyond the scope of cancer metabolism. We discuss the scope of these findings in the context of developing portable, real-time metabolic measurement systems that can find applications in preclinical and clinical diagnostics. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. B-Cell Metabolic Remodeling and Cancer

    DEFF Research Database (Denmark)

    Franchina, Davide G.; Grusdat, Melanie; Brenner, Dirk

    2018-01-01

    of the current state of the art and describe the main metabolic features of B cells during normal development and oncogenesis, with emphasis on the major B-cell transcriptional and metabolic regulators, including myelocytomatosis virus oncogene cellular homolog (Myc) and hypoxia-inducible factor 1-α (HIF-1α)....

  19. Miniaturized, Portable Sensors Monitor Metabolic Health

    Science.gov (United States)

    2014-01-01

    In order to measure astronauts' metabolic rates in space, Glenn Research Center partnered with Case Western University and the Cleveland Clinic to develop the Portable Unit for Metabolic Analysis (PUMA). Cleveland-based Orbital Research licensed and then modified PUMA to help the US Navy assess pilot oxygen problems and is now designing a device that can be used in hospitals.

  20. Prenatal diagnosis of inherited metabolic diseases.

    OpenAIRE

    Diukman, R; Goldberg, J D

    1993-01-01

    Advances in the prenatal diagnosis of inherited metabolic disease have provided new reproductive options to at-risk couples. These advances have occurred in both sampling techniques and methods of analysis. In this review we present an overview of the currently available prenatal diagnostic approaches for the diagnosis of metabolic disease in a fetus.