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Sample records for acidithiobacillus ferrooxidans metabolism

  1. Microarray and bioinformatic analyses suggest models for carbon metabolism in the autotroph Acidithiobacillus ferrooxidans

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    C. Appia-ayme; R. Quatrini; Y. Denis; F. Denizot; S. Silver; F. Roberto; F. Veloso; J. Valdes; J. P. Cardenas; M. Esparza; O. Orellana; E. Jedlicki; V. Bonnefoy; D. Holmes

    2006-09-01

    Acidithiobacillus ferrooxidans is a chemolithoautotrophic bacterium that uses iron or sulfur as an energy and electron source. Bioinformatic analysis was used to identify putative genes and potential metabolic pathways involved in CO2 fixation, 2P-glycolate detoxification, carboxysome formation and glycogen utilization in At. ferrooxidans. Microarray transcript profiling was carried out to compare the relative expression of the predicted genes of these pathways when the microorganism was grown in the presence of iron versus sulfur. Several gene expression patterns were confirmed by real-time PCR. Genes for each of the above predicted pathways were found to be organized into discrete clusters. Clusters exhibited differential gene expression depending on the presence of iron or sulfur in the medium. Concordance of gene expression within each cluster, suggested that they are operons Most notably, clusters of genes predicted to be involved in CO2 fixation, carboxysome formation, 2P-glycolate detoxification and glycogen biosynthesis were up-regulated in sulfur medium, whereas genes involved in glycogen utilization were preferentially expressed in iron medium. These results can be explained in terms of models of gene regulation that suggest how A. ferrooxidans can adjust its central carbon management to respond to changing environmental conditions.

  2. Metabolic reconstruction of sulfur assimilation in the extremophile Acidithiobacillus ferrooxidans based on genome analysis

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    Jedlicki Eugenia

    2003-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is a gamma-proteobacterium that lives at pH2 and obtains energy by the oxidation of sulfur and iron. It is used in the biomining industry for the recovery of metals and is one of the causative agents of acid mine drainage. Effective tools for the study of its genetics and physiology are not in widespread use and, despite considerable effort, an understanding of its unusual physiology remains at a rudimentary level. Nearly complete genome sequences of A. ferrooxidans are available from two public sources and we have exploited this information to reconstruct aspects of its sulfur metabolism. Results Two candidate mechanisms for sulfate uptake from the environment were detected but both belong to large paralogous families of membrane transporters and their identification remains tentative. Prospective genes, pathways and regulatory mechanisms were identified that are likely to be involved in the assimilation of sulfate into cysteine and in the formation of Fe-S centers. Genes and regulatory networks were also uncovered that may link sulfur assimilation with nitrogen fixation, hydrogen utilization and sulfur reduction. Potential pathways were identified for sulfation of extracellular metabolites that may possibly be involved in cellular attachment to pyrite, sulfur and other solid substrates. Conclusions A bioinformatic analysis of the genome sequence of A. ferrooxidans has revealed candidate genes, metabolic process and control mechanisms potentially involved in aspects of sulfur metabolism. Metabolic modeling provides an important preliminary step in understanding the unusual physiology of this extremophile especially given the severe difficulties involved in its genetic manipulation and biochemical analysis.

  3. Metabolic reconstruction of sulfur assimilation in the extremophile Acidithiobacillus ferrooxidans based on genome analysis

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    Valdés, Jorge; Veloso, Felipe; Jedlicki, Eugenia; Holmes, David

    2003-01-01

    Background Acidithiobacillus ferrooxidans is a gamma-proteobacterium that lives at pH2 and obtains energy by the oxidation of sulfur and iron. It is used in the biomining industry for the recovery of metals and is one of the causative agents of acid mine drainage. Effective tools for the study of its genetics and physiology are not in widespread use and, despite considerable effort, an understanding of its unusual physiology remains at a rudimentary level. Nearly complete genome sequences of A. ferrooxidans are available from two public sources and we have exploited this information to reconstruct aspects of its sulfur metabolism. Results Two candidate mechanisms for sulfate uptake from the environment were detected but both belong to large paralogous families of membrane transporters and their identification remains tentative. Prospective genes, pathways and regulatory mechanisms were identified that are likely to be involved in the assimilation of sulfate into cysteine and in the formation of Fe-S centers. Genes and regulatory networks were also uncovered that may link sulfur assimilation with nitrogen fixation, hydrogen utilization and sulfur reduction. Potential pathways were identified for sulfation of extracellular metabolites that may possibly be involved in cellular attachment to pyrite, sulfur and other solid substrates. Conclusions A bioinformatic analysis of the genome sequence of A. ferrooxidans has revealed candidate genes, metabolic process and control mechanisms potentially involved in aspects of sulfur metabolism. Metabolic modeling provides an important preliminary step in understanding the unusual physiology of this extremophile especially given the severe difficulties involved in its genetic manipulation and biochemical analysis. PMID:14675496

  4. Magnetic properties of Acidithiobacillus ferrooxidans.

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    Yan, Lei; Zhang, Shuang; Chen, Peng; Wang, Weidong; Wang, Yanjie; Li, Hongyu

    2013-10-01

    Understanding the magnetic properties of magnetotactic bacteria (MTBs) is of great interest in fields of life sciences, geosciences, biomineralization, biomagnetism, and planetary sciences. Acidithiobacillus ferrooxidans (At. ferrooxidans), obtaining energy through the oxidation of ferrous iron and various reduced inorganic sulfur compounds, can synthesize intracellular magnetite magnetosomes. However, the magnetic properties of such microorganism remain unknown. Here we used transmission electronmicroscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) assay, vibrating sample magnetometer (VSM), magneto-thermogravimetric analysis (MTGA), and low temperature magnetometry to comprehensively investigate the magnetic characteristics of At. ferrooxidans. Results revealed that each cell contained only 1 to 3 magnetite magnetosomes, which were arranged irregularly. The magnetosomes were generally in a stable single-domain (SD) state, but superparamagnetic (SP) magnetite particles were also found. The calcined bacteria exhibited a ferromagnetic behavior with a Curie Temperature of 454 °C and a coercivity of 16.36 mT. Additionally, the low delta ratio (δFC/δZFC=1.27) indicated that there were no intact magnetosome chains in At. ferrooxidans. Our results provided the new insights on the biomineralization of bacterial magnetosomes and magnetic properties of At. ferrooxidans. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  5. Magnetic properties of Acidithiobacillus ferrooxidans

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    Yan, Lei; Zhang, Shuang [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 (China); Chen, Peng [Gansu Institute of Business and Technology, Lanzhou, 730010 (China); Wang, Weidong; Wang, Yanjie [College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, 163319 (China); Li, Hongyu, E-mail: hekouyanlei@gmail.com [Institute of Microbiology, School of Life Sciences, Lanzhou University, Lanzhou, 730000 (China)

    2013-10-15

    Understanding the magnetic properties of magnetotactic bacteria (MTBs) is of great interest in fields of life sciences, geosciences, biomineralization, biomagnetism, and planetary sciences. Acidithiobacillus ferrooxidans (At. ferrooxidans), obtaining energy through the oxidation of ferrous iron and various reduced inorganic sulfur compounds, can synthesize intracellular magnetite magnetosomes. However, the magnetic properties of such microorganism remain unknown. Here we used transmission electronmicroscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) assay, vibrating sample magnetometer (VSM), magneto–thermogravimetric analysis (MTGA), and low temperature magnetometry to comprehensively investigate the magnetic characteristics of At. ferrooxidans. Results revealed that each cell contained only 1 to 3 magnetite magnetosomes, which were arranged irregularly. The magnetosomes were generally in a stable single-domain (SD) state, but superparamagnetic (SP) magnetite particles were also found. The calcined bacteria exhibited a ferromagnetic behavior with a Curie Temperature of 454 °C and a coercivity of 16.36 mT. Additionally, the low delta ratio (δ{sub FC}/δ{sub ZFC} = 1.27) indicated that there were no intact magnetosome chains in At. ferrooxidans. Our results provided the new insights on the biomineralization of bacterial magnetosomes and magnetic properties of At. ferrooxidans. - Highlights: • Rock magnetic investigations carried out on At.ferrooxidans in detail. • Results indicated that each cell contained 1 to 3 scattered magnetite magnetosomes. • The magnetosomes consist of SD and SP magnetite nanoparticles. • Cells showed ferromagnetic behavior with high Curie Temperature and low δ{sub FC}/δ{sub ZFC}. • Results are useful in studying the magnetosomes biomineralization.

  6. Anaerobic sulfur metabolism coupled to dissimilatory iron reduction in the extremophile Acidithiobacillus ferrooxidans.

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    Osorio, Héctor; Mangold, Stefanie; Denis, Yann; Ñancucheo, Ivan; Esparza, Mario; Johnson, D Barrie; Bonnefoy, Violaine; Dopson, Mark; Holmes, David S

    2013-04-01

    Gene transcription (microarrays) and protein levels (proteomics) were compared in cultures of the acidophilic chemolithotroph Acidithiobacillus ferrooxidans grown on elemental sulfur as the electron donor under aerobic and anaerobic conditions, using either molecular oxygen or ferric iron as the electron acceptor, respectively. No evidence supporting the role of either tetrathionate hydrolase or arsenic reductase in mediating the transfer of electrons to ferric iron (as suggested by previous studies) was obtained. In addition, no novel ferric iron reductase was identified. However, data suggested that sulfur was disproportionated under anaerobic conditions, forming hydrogen sulfide via sulfur reductase and sulfate via heterodisulfide reductase and ATP sulfurylase. Supporting physiological evidence for H2S production came from the observation that soluble Cu(2+) included in anaerobically incubated cultures was precipitated (seemingly as CuS). Since H(2)S reduces ferric iron to ferrous in acidic medium, its production under anaerobic conditions indicates that anaerobic iron reduction is mediated, at least in part, by an indirect mechanism. Evidence was obtained for an alternative model implicating the transfer of electrons from S(0) to Fe(3+) via a respiratory chain that includes a bc(1) complex and a cytochrome c. Central carbon pathways were upregulated under aerobic conditions, correlating with higher growth rates, while many Calvin-Benson-Bassham cycle components were upregulated during anaerobic growth, probably as a result of more limited access to carbon dioxide. These results are important for understanding the role of A. ferrooxidans in environmental biogeochemical metal cycling and in industrial bioleaching operations.

  7. 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

  8. 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.

  9. Global transcriptional responses of Acidithiobacillus ferrooxidans Wenelen under different sulfide minerals.

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    Latorre, Mauricio; Ehrenfeld, Nicole; Cortés, María Paz; Travisany, Dante; Budinich, Marko; Aravena, Andrés; González, Mauricio; Bobadilla-Fazzini, Roberto A; Parada, Pilar; Maass, Alejandro

    2016-01-01

    In order to provide new information about the adaptation of Acidithiobacillus ferrooxidans during the bioleaching process, the current analysis presents the first report of the global transcriptional response of the native copper mine strain Wenelen (DSM 16786) oxidized under different sulfide minerals. Microarrays were used to measure the response of At. ferrooxidans Wenelen to shifts from iron supplemented liquid cultures (reference state) to the addition of solid substrates enriched in pyrite or chalcopyrite. Genes encoding for energy metabolism showed a similar transcriptional profile for the two sulfide minerals. Interestingly, four operons related to sulfur metabolism were over-expressed during growth on a reduced sulfur source. Genes associated with metal tolerance (RND and ATPases type P) were up-regulated in the presence of pyrite or chalcopyrite. These results suggest that At. ferrooxidans Wenelen presents an efficient transcriptional system developed to respond to environmental conditions, namely the ability to withstand high copper concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Periplasmic proteins of the extremophile Acidithiobacillus ferrooxidans: a high throughput proteomics analysis.

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    Chi, An; Valenzuela, Lissette; Beard, Simon; Mackey, Aaron J; Shabanowitz, Jeffrey; Hunt, Donald F; Jerez, Carlos A

    2007-12-01

    Acidithiobacillus ferrooxidans is a chemolithoautotrophic acidophile capable of obtaining energy by oxidizing ferrous iron or sulfur compounds such as metal sulfides. Some of the proteins involved in these oxidations have been described as forming part of the periplasm of this extremophile. The detailed study of the periplasmic components constitutes an important area to understand the physiology and environmental interactions of microorganisms. Proteomics analysis of the periplasmic fraction of A. ferrooxidans ATCC 23270 was performed by using high resolution linear ion trap-FT MS. We identified a total of 131 proteins in the periplasm of the microorganism grown in thiosulfate. When possible, functional categories were assigned to the proteins: 13.8% were transport and binding proteins, 14.6% were several kinds of cell envelope proteins, 10.8% were involved in energy metabolism, 10% were related to protein fate and folding, 10% were proteins with unknown functions, and 26.1% were proteins without homologues in databases. These last proteins are most likely characteristic of A. ferrooxidans and may have important roles yet to be assigned. The majority of the periplasmic proteins from A. ferrooxidans were very basic compared with those of neutrophilic microorganisms such as Escherichia coli, suggesting a special adaptation of the chemolithoautotrophic bacterium to its very acidic environment. The high throughput proteomics approach used here not only helps to understand the physiology of this extreme acidophile but also offers an important contribution to the functional annotation for the available genomes of biomining microorganisms such as A. ferrooxidans for which no efficient genetic systems are available to disrupt genes by procedures such as homologous recombination.

  11. 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.

  12. Extending the models for iron and sulfur oxidation in the extreme Acidophile Acidithiobacillus ferrooxidans

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    Holmes David S

    2009-08-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans gains energy from the oxidation of ferrous iron and various reduced inorganic sulfur compounds at very acidic pH. Although an initial model for the electron pathways involved in iron oxidation has been developed, much less is known about the sulfur oxidation in this microorganism. In addition, what has been reported for both iron and sulfur oxidation has been derived from different A. ferrooxidans strains, some of which have not been phylogenetically characterized and some have been shown to be mixed cultures. It is necessary to provide models of iron and sulfur oxidation pathways within one strain of A. ferrooxidans in order to comprehend the full metabolic potential of the pangenome of the genus. Results Bioinformatic-based metabolic reconstruction supported by microarray transcript profiling and quantitative RT-PCR analysis predicts the involvement of a number of novel genes involved in iron and sulfur oxidation in A. ferrooxidans ATCC23270. These include for iron oxidation: cup (copper oxidase-like, ctaABT (heme biogenesis and insertion, nuoI and nuoK (NADH complex subunits, sdrA1 (a NADH complex accessory protein and atpB and atpE (ATP synthetase F0 subunits. The following new genes are predicted to be involved in reduced inorganic sulfur compounds oxidation: a gene cluster (rhd, tusA, dsrE, hdrC, hdrB, hdrA, orf2, hdrC, hdrB encoding three sulfurtransferases and a heterodisulfide reductase complex, sat potentially encoding an ATP sulfurylase and sdrA2 (an accessory NADH complex subunit. Two different regulatory components are predicted to be involved in the regulation of alternate electron transfer pathways: 1 a gene cluster (ctaRUS that contains a predicted iron responsive regulator of the Rrf2 family that is hypothesized to regulate cytochrome aa3 oxidase biogenesis and 2 a two component sensor-regulator of the RegB-RegA family that may respond to the redox state of the quinone pool

  13. Growth of the acidophilic iron-sulfur bacterium Acidithiobacillus ferrooxidans under Mars-like geochemical conditions

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    Bauermeister, Anja; Rettberg, Petra; Flemming, Hans-Curt

    2014-08-01

    The question of life on Mars has been in focus of astrobiological research for several decades, and recent missions in orbit or on the surface of the planet are constantly expanding our knowledge on Martian geochemistry. For example, massive stratified deposits have been identified on Mars containing sulfate minerals and iron oxides, which suggest the existence of acidic aqueous conditions in the past, similar to acidic iron- and sulfur-rich environments on Earth. Acidophilic organisms thriving in such habitats could have been an integral part of a possibly widely extinct Martian ecosystem, but remains might possibly even exist today in protected subsurface niches. The chemolithoautotrophic strain Acidithiobacillus ferrooxidans was selected as a model organism to study the metabolic capacities of acidophilic iron-sulfur bacteria, especially regarding their ability to grow with in situ resources that could be expected on Mars. The experiments were not designed to accurately simulate Martian physical conditions (except when certain single parameters such as oxygen partial pressure were considered), but rather the geochemical environment that can be found on Mars. A. ferrooxidans could grow solely on the minerals contained in synthetic Mars regolith mixtures with no added nutrients, using either O2 as an external electron acceptor for iron oxidation, or H2 as an external electron donor for iron reduction, and thus might play important roles in the redox cycling of iron on Mars. Though the oxygen partial pressure of the Martian atmosphere at the surface was not sufficient for detectable iron oxidation and growth of A. ferrooxidans during short-term incubation (7 days), alternative chemical O2-generating processes in the subsurface might yield microhabitats enriched in oxygen, which principally are possible under such conditions. The bacteria might also contribute to the reductive dissolution of Fe3+-containing minerals like goethite and hematite, which are

  14. Are there multiple mechanisms of anaerobic sulfur oxidation with ferric iron in Acidithiobacillus ferrooxidans?

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    Kucera, Jiri; Pakostova, Eva; Lochman, Jan; Janiczek, Oldrich; Mandl, Martin

    2016-06-01

    To clarify the pathway of anaerobic sulfur oxidation coupled with dissimilatory ferric iron reduction in Acidithiobacillus ferrooxidans strain CCM 4253 cells, we monitored their energy metabolism gene transcript profiles. Several genes encoding electron transporters involved in aerobic iron and sulfur respiration were induced during anaerobic growth of ferrous iron-grown cells. Most sulfur metabolism genes were either expressed at the basal level or their expression declined. However, transcript levels of genes assumed to be responsible for processing of elemental sulfur and other sulfur intermediates were elevated at the beginning of the growth period. In contrast, genes with predicted functions in formation of hydrogen sulfide and sulfate were significantly repressed. The main proposed mechanism involves: outer membrane protein Cyc2 (assumed to function as a terminal ferric iron reductase); periplasmic electron shuttle rusticyanin; c4-type cytochrome CycA1; the inner membrane cytochrome bc1 complex I; and the quinone pool providing connection to the sulfur metabolism machinery, consisting of heterodisulfide reductase, thiosulfate:quinone oxidoreductase and tetrathionate hydrolase. However, an alternative mechanism seems to involve a high potential iron-sulfur protein Hip, c4-type cytochrome CycA2 and inner membrane cytochrome bc1 complex II. Our results conflict with findings regarding the type strain, indicating strain- or phenotype-dependent pathway variation. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  15. 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.

  16. Characterization of endogenous promoters for control of recombinant gene expression in Acidithiobacillus ferrooxidans.

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    Kernan, Timothy; West, Alan C; Banta, Scott

    2017-11-01

    Acidithiobacillus ferrooxidans is an important iron- and sulfur-oxidizing acidophilic chemolithoautotroph that is used extensively in metal extraction and refining, and more recently in the bioproduction of chemicals. However, a lack of genetic tools has limited the further development of this organism for industrial bioprocesses. Using prior microarray studies that identified genes, which may express differentially in response to the availability of iron and sulfur, the cycA1 and tusA promoter sequences have been characterized for their ability to drive green fluorescent protein expression. The promoters exhibited opposite control behavior, where the cycA1 sequence was repressed and the tusA promoter was induced by the presence of sulfur in the growth medium. Sulfur was found to be the dominant signal. The sulfur IC 50 for cycA1 was 0.56 mM (18 mg/L), whereas the sulfur EC 50 of tusA was 2.5 mM (80 mg/L). Together these sequences provide two new tools to selectively induce or repress gene expression in A. ferrooxidans. Acidithiobacillus ferrooxidans is an important industrial organism; however, genetic tools for control of gene expression do not exist. Here, we report the identification of promoter sequences that allow for the development of control of gene expression for engineering this organism. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  17. Preliminary X-ray crystallographic analysis of sulfide:quinone oxidoreductase from Acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Zhang, Yanfei; Cherney, Maia M.; Solomonson, Matthew; Liu, Jianshe; James, Michael N. G.; Weiner, Joel H.

    2009-01-01

    The sulfide:quinone oxidoreductase from A. ferrooxidans ATCC 23270 was overexpressed in E. coli and purified. Crystallization and preliminarily X-ray crystallographic analysis were performed for the recombinant enzyme. The gene product of open reading frame AFE-1293 from Acidithiobacillus ferrooxidans ATCC 23270 is annotated as encoding a sulfide:quinone oxidoreductase, an enzyme that catalyses electron transfer from sulfide to quinone. Following overexpression in Escherichia coli, the enzyme was purified and crystallized using the hanging-drop vapour-diffusion method. The native crystals belonged to the tetragonal space group P4 2 2 1 2, with unit-cell parameters a = b = 131.7, c = 208.8 Å, and diffracted to 2.3 Å resolution. Preliminary crystallographic analysis indicated the presence of a dimer in the asymmetric unit, with an extreme value of the Matthews coefficient (V M ) of 4.53 Å 3 Da −1 and a solvent content of 72.9%

  18. 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

  19. 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.

  20. [Effect of temperature on activity of Acidithiobacillus ferrooxidan and formation of biogenic secondary iron minerals].

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    Song, Yong-Wei; Zhao, Bo-Wen; Huo, Min-Bo; Cui, Chun-Hong; Zhou, Li-Xiang

    2013-08-01

    In this study, batch experiments were performed to investigate the effect of temperature on the Fe (II) oxidation and the formation of biogenic secondary iron minerals by Acidithiobacillus ferrooxidan. Results showed that the low temperature significantly inhibited the oxidation activity of A. ferrooxidan. In the FeSO4-H2O biological oxidation system facilitated by A. ferrooxidan, it was found that after 5 days culture, the oxidation rates of Fe (II) in treatments of 10 degrees C and 28 degrees C were 11.81% and 100%, respectively. In addition, it rapidly rose to 95.10% when the temperature was adjusted from 10 degrees C (cultured for 7 days) to 28 degrees C in 1 day, and the maximum oxidation rates were as follows: 10 degrees C (cultured for 7 days) +28 degrees C (2.25 h(-1)) > 28 degrees C (1.42 h(-1)) >10 degrees C (0.81 h(-1)). Furthermore, the XRD patterns showed that the lower Fe (III) supply rate was more conducive to the formation of amorphous schwertmannite in 9K medium at 10 degrees C. Correspondingly, the generation of amorphous schwertmannite was preceded to ihleite at 28 degrees C, and the crystallinity degree of ihleite was getting better with the extension of culture time. Combined with the SEM characteristics, it was judged that the 28 degrees C sample contained jarosite and schwertmannite.

  1. Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila, Mexico

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    Núñez-Ramírez, Diola Marina; Solís-Soto, Aquiles; López-Miranda, Javier; Pereyra-Alférez, Benito; Rutiaga-Quiñónes, Miriam; Medina-Torres, Luis; Medrano-Roldán, Hiram

    2011-10-01

    The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans ( A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.

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

    Science.gov (United States)

    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

  3. A new cytoplasmic monoheme cytochrome c from Acidithiobacillus ferrooxidans involved in sulfur oxidation.

    Science.gov (United States)

    Liu, Yuandong; Guo, Shuhui; Yu, Runlan; Zou, Kai; Qiu, Guanzhou

    2014-03-01

    Acidithiobacillus ferrooxidans can obtain energy from the oxidation of various reduced inorganic sulfur compounds (RISCs, e.g., sulfur) and ferrous iron in bioleaching so has multiple branched respiratory pathways with a diverse range of electron transporters, especially cytochrome c proteins. A cytochrome c family gene, afe1130, which has never been reported before, was found by screening the whole genome of A. ferrooxidans. Here we report the differential gene transcription, bioinformatics analysis, and molecular modeling of the protein encoded by the afe1130 gene (AFE1130). The differential transcription of the target afe1130 gene versus the reference rrs gene in the A. ferrooxidans, respectively, on the culture conditions of sulfur and ferrous energy sources was performed through quantitative reverse transcription polymerase chain reaction (qRT-PCR) with a SYBR green-based assay according to the standard curves method. The qRT-PCR results showed that the afe1130 gene in sulfur culture condition was obviously more transcribed than that in ferrous culture condition. Bioinformatics analysis indicated that the AFE1130 was affiliated to the subclass ID of class I of cytochrome c and located in cytoplasm. Molecular modeling results exhibited that the AFE1130 protein consisted of 5 alpha-helices harboring one heme c group covalently bonded by Cys13 and Cys16 and ligated by His17 and Met62 and owned a big raised hydrophobic surface responsible for attaching to inner cytomembrane. So the AFE1130 in A. ferrooxidans plays a role in the RISCs oxidation in bioleaching in cytoplasm bound to inner membrane.

  4. New copper resistance determinants in the extremophile acidithiobacillus ferrooxidans: a quantitative proteomic analysis.

    Science.gov (United States)

    Almárcegui, Rodrigo J; Navarro, Claudio A; Paradela, Alberto; Albar, Juan Pablo; von Bernath, Diego; Jerez, Carlos A

    2014-02-07

    Acidithiobacillus ferrooxidans is an extremophilic bacterium used in biomining processes to recover metals. The presence in A. ferrooxidans ATCC 23270 of canonical copper resistance determinants does not entirely explain the extremely high copper concentrations this microorganism is able to stand, suggesting the existence of other efficient copper resistance mechanisms. New possible copper resistance determinants were searched by using 2D-PAGE, real time PCR (qRT-PCR) and quantitative proteomics with isotope-coded protein labeling (ICPL). A total of 594 proteins were identified of which 120 had altered levels in cells grown in the presence of copper. Of this group of proteins, 76 were up-regulated and 44 down-regulated. The up-regulation of RND-type Cus systems and different RND-type efflux pumps was observed in response to copper, suggesting that these proteins may be involved in copper resistance. An overexpression of most of the genes involved in histidine synthesis and several of those annotated as encoding for cysteine production was observed in the presence of copper, suggesting a possible direct role for these metal-binding amino acids in detoxification. Furthermore, the up-regulation of putative periplasmic disulfide isomerases was also seen in the presence of copper, suggesting that they restore copper-damaged disulfide bonds to allow cell survival. Finally, the down-regulation of the major outer membrane porin and some ionic transporters was seen in A. ferrooxidans grown in the presence of copper, indicating a general decrease in the influx of the metal and other cations into the cell. Thus, A. ferrooxidans most likely uses additional copper resistance strategies in which cell envelope proteins are key components. This knowledge will not only help to understand the mechanism of copper resistance in this extreme acidophile but may help also to select the best fit members of the biomining community to attain more efficient industrial metal leaching

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. Effect of Extracellular Polymeric Substances on Surface Properties and Attachment Behavior of Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Qian Li

    2016-09-01

    Full Text Available Bacterial contact leaching of ores is more effective than non-contact leaching. Adhesion is the first step for leaching bacteria to form a biofilm on a mineral surface. Extracellular polymeric substances (EPS are pivotal for mediating bacterial adhesion to a substratum. In order to clarify the role of EPS, we measured the adhesion forces between chalcopyrite-, sulfur- or FeSO4·7H2O-grown cells of Acidithiobacillus ferrooxidans and chalcopyrite by an atomic force microscope (AFM before and after EPS removal. Surface properties of these cells were assessed by measurements of the contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR and acid-base titration. Bacterial attachment to chalcopyrite was monitored for 140 min. The results indicate that the EPS control the surface properties of the cells. In addition, the surface properties are decisive for adhesion. The adhesion forces and the amounts of attached cells decreased dramatically after removing EPS, which was not dependent on the preculture.

  13. Characterization of arsenic resistant and arsenopyrite oxidizing Acidithiobacillus ferrooxidans from Hutti gold leachate and effluents.

    Science.gov (United States)

    Dave, Shailesh R; Gupta, Kajal H; Tipre, Devayani R

    2008-11-01

    Four arsenic resistant ferrous oxidizers were isolated from Hutti Gold Mine Ltd. (HGML) samples. Characterization of these isolates was done using conventional microbiological, biochemical and molecular methods. The ferrous oxidation rates with these isolates were 16, 48, 34 and 34 mg L(-1)h(-1) and 15, 47, 34 and 32 mg L(-1)h(-1) in absence and presence of 20 mM of arsenite (As3+) respectively. Except isolate HGM 8, other three isolates showed 2.9-6.3% inhibition due to the presence of 20 mM arsenite. Isolate HGM 8 was able to grow in presence of 14.7 g L(-1) of arsenite, with 25.77 mg L(-1)h(-1) ferrous oxidation rate. All the four isolates were able to oxidize iron and arsenopyrite from 20 g L(-1) and 40 g L(-1) refractory gold ore and 20 g L(-1) refractory gold concentrate. Once the growth was established pH adjustment was not needed inspite of ferrous oxidation, which could be due to concurrent oxidation of pyrite. Isolate HGM 8 showed the final cell count of as high as 1.12 x 10(8) cells mL(-1) in 40 g L(-1) refractory gold ore. The isolates were grouped into one haplotypes by amplified ribosomal DNA restriction analysis (ARDRA). The phylogenetic position of HGM 8 was determined by 16S rDNA sequencing. It was identified as Acidithiobacillus ferrooxidans and strain name was given as SRHGM 1.

  14. A Tyrosine-Dependent Riboswitch Controls the Expression of a Tyrosyl-tRNA Synthetase from Acidithiobacillus ferrooxidans

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    Paula Bustamante

    2016-06-01

    Full Text Available Expression of aminoacyl-tRNA synthetases is regulated by a variety of mechanisms at the level of transcription or translation. A T-box dependent transcription termination / antitermination riboswitch system that responds to charged / uncharged tRNA regulates expression of aminoacyl tRNA synthetase genes in Gram-positive bacteria. TyrZ, the gene encoding tyrosyl-tRNA synthetase from Acidithiobacillus ferrooxidans, a Gram-negative acidophilic bacterium that participates in bioleaching of minerals, resembles the gene from Bacillus subtilis including the 5´-untranslated region encoding the riboswitch. Transcription of A. ferrooxidans tyrZ is induced by the presence of tyrosine by a mechanism involving antitermination of transcription. This mechanism is probably adapted to the low supply of amino acids of acidic environments of autotrophic bioleaching microorganisms. This work is licensed under a Creative Commons Attribution 4.0 International License.

  15. Selection and evaluation of reference genes for improved interrogation of microbial transcriptomes: case study with the extremophile Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Nieto, Pamela A; Covarrubias, Paulo C; Jedlicki, Eugenia; Holmes, David S; Quatrini, Raquel

    2009-06-25

    Normalization is a prerequisite for accurate real time PCR (qPCR) expression analysis and for the validation of microarray profiling data in microbial systems. The choice and use of reference genes that are stably expressed across samples, experimental conditions and designs is a key consideration for the accurate interpretation of gene expression data. Here, we evaluate a carefully selected set of reference genes derived from previous microarray-based transcriptional profiling experiments performed on Acidithiobacillus ferrooxidans and identify a set of genes with minimal variability under five different experimental conditions that are frequently used in Acidithiobacilli research. Suitability of these and other previously reported reference genes to monitor the expression of four selected target genes from A. ferrooxidans grown with different energy sources was investigated. Utilization of reference genes map, rpoC, alaS and era results in improved interpretation of gene expression profiles in A. ferrooxidans. This investigation provides a validated set of reference genes for studying A. ferrooxidans gene expression under typical biological conditions and an initial point of departure for exploring new experimental setups in this microorganism and eventually in other closely related Acidithiobacilli. The information could also be of value for future transcriptomic experiments in other bacterial systems.

  16. Selection and evaluation of reference genes for improved interrogation of microbial transcriptomes: case study with the extremophile Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Holmes David S

    2009-06-01

    Full Text Available Abstract Background Normalization is a prerequisite for accurate real time PCR (qPCR expression analysis and for the validation of microarray profiling data in microbial systems. The choice and use of reference genes that are stably expressed across samples, experimental conditions and designs is a key consideration for the accurate interpretation of gene expression data. Results Here, we evaluate a carefully selected set of reference genes derived from previous microarray-based transcriptional profiling experiments performed on Acidithiobacillus ferrooxidans and identify a set of genes with minimal variability under five different experimental conditions that are frequently used in Acidithiobacilli research. Suitability of these and other previously reported reference genes to monitor the expression of four selected target genes from A. ferrooxidans grown with different energy sources was investigated. Utilization of reference genes map, rpoC, alaS and era results in improved interpretation of gene expression profiles in A. ferrooxidans. Conclusion This investigation provides a validated set of reference genes for studying A. ferrooxidans gene expression under typical biological conditions and an initial point of departure for exploring new experimental setups in this microorganism and eventually in other closely related Acidithiobacilli. The information could also be of value for future transcriptomic experiments in other bacterial systems.

  17. 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.

  18. 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

  19. 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.

  20. Comparative genomics unravels metabolic differences at the species and/or strain level and extremely acidic environmental adaptation of ten bacteria belonging to the genus Acidithiobacillus.

    Science.gov (United States)

    Zhang, Xian; She, Siyuan; Dong, Weiling; Niu, Jiaojiao; Xiao, Yunhua; Liang, Yili; Liu, Xueduan; Zhang, Xiaoxia; Fan, Fenliang; Yin, Huaqun

    2016-12-01

    Members of the Acidithiobacillus genus are widely found in extreme environments characterized by low pH and high concentrations of toxic substances, thus it is necessary to identify the cellular mechanisms needed to cope with these harsh conditions. Pan-genome analysis of ten bacteria belonging to the genus Acidithiobacillus suggested the existence of core genome, most of which were assigned to the metabolism-associated genes. Additionally, the unique genes of Acidithiobacillus ferrooxidans were much less than those of other species. A large proportion of Acidithiobacillus ferrivorans-specific genes were mapped especially to metabolism-related genes, indicating that diverse metabolic pathways might confer an advantage for adaptation to local environmental conditions. Analyses of functional metabolisms revealed the differences of carbon metabolism, nitrogen metabolism, and sulfur metabolism at the species and/or strain level. The findings also showed that Acidithiobacillus spp. harbored specific adaptive mechanisms for thriving under extreme environments. The genus Acidithiobacillus had the genetic potential to resist and metabolize toxic substances such as heavy metals and organic solvents. Comparison across species and/or strains of Acidithiobacillus populations provided a deeper appreciation of metabolic differences and environmental adaptation, as well as highlighting the importance of cellular mechanisms that maintain the basal physiological functions under complex acidic environmental conditions. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Bevilaqua Denise

    2003-01-01

    Full Text Available 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 evolution of impedance diagrams obtained during the time course of experiments. The main difference in these diagrams was the presence of an inductive feature (up to 44 h, which was related to bacterial action on the mineral dissolution, better than to its adhesion on the bornite. The total real impedance measured in presence of the bacterium was about 10 times lower than in its absence, due to the acceleration of the mineral dissolution, because an oxidant environment was maintained.

  2. Effect of energy source, salt concentration and loading force on colloidal interactions between Acidithiobacillus ferrooxidans cells and mineral surfaces.

    Science.gov (United States)

    Diao, Mengxue; Nguyen, Tuan A H; Taran, Elena; Mahler, Stephen M; Nguyen, Anh V

    2015-08-01

    The surface appendages and extracellular polymeric substances of cells play an important role in the bacterial adhesion process. In this work, colloidal forces and nanomechanical properties of Acidithiobacillus ferrooxidans (A. f) interacted with silicon wafer and pyrite (FeS2) surfaces in solutions of varying salt concentrations were quantitatively examined using the bacterial probe technique with atomic force microscopy. A. f cells were cultured with either ferrous sulfate or elemental sulfur as key energy sources. Our results show that A. f cells grown with ferrous ion and elemental sulfur exhibit distinctive retraction force vs separation distance curves with stair-step and saw tooth shapes, respectively. During the approach of bacterial probes to the substrate surfaces, surface appendages and biopolymers of cells are sequentially compressed. The conformations of surface appendages and biopolymers are significantly influenced by the salt concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. The extremophile Acidithiobacillus ferrooxidans possesses a c-di-GMP signalling pathway that could play a significant role during bioleaching of minerals.

    Science.gov (United States)

    Ruiz, L M; Castro, M; Barriga, A; Jerez, C A; Guiliani, N

    2012-02-01

      The primary goal of this study was to characterize the existence of a functional c-di-GMP pathway in the bioleaching bacterium Acidithiobacillus ferrooxidans.   A bioinformatic search revealed that the genome sequence of At. ferrooxidans ATCC 23270 codes for several proteins involved in the c-di-GMP pathway, including diguanylate cyclases (DGC), phosphodiesterases and PilZ effector proteins. Overexpression in Escherichia coli demonstrated that four At. ferrooxidans genes code for proteins containing GGDEF/EAL domains with functional DGC activity. MS/MS analysis allowed the identification of c-di-GMP in nucleotide preparations obtained from At. ferrooxidans cells. In addition, c-di-GMP levels in cells grown on the surface of solid energetic substrates such as sulfur prills or pyrite were higher than those measured in ferrous iron planktonic cells.   At. ferrooxidans possesses a functional c-di-GMP pathway that could play a key role in At. ferrooxidans biofilm formation during bioleaching processes.   This is the first global study about the c-di-GMP pathway in an acidophilic bacterium of great interest for the biomining industry. It opens a new way to explore the regulation of biofilm formation by biomining micro-organisms during the bioleaching process. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  4. METABOLISMO DEL FOSFATO EN ACIDITHIOBACILLUS FERROOXIDANS: CARACTERIZACION DE UN POSIBLE REGULON PHO

    OpenAIRE

    VERA VELIZ, MARIO ANDRES; VERA VELIZ, MARIO ANDRES

    2006-01-01

    El microorganismo quimiolitoautotrófico Acidithiobaci/Ius ferrooxidans es de gran importancia en la hiominería. Durante el proceso de biolixiviación de minerales pueden producirse diversos tipos de estrés como cambios de pH y temperatura, además de la car 106p.

  5. Attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum cultured under varying conditions to pyrite, chalcopyrite, low-grade ore and quartz in a packed column reactor.

    Science.gov (United States)

    Africa, Cindy-Jade; van Hille, Robert P; Harrison, Susan T L

    2013-02-01

    The attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum spp. grown on ferrous medium or adapted to a pyrite mineral concentrate to four mineral substrata, namely, chalcopyrite and pyrite concentrates, a low-grade chalcopyrite ore (0.5 wt%) and quartzite, was investigated. The quartzite represented a typical gangue mineral and served as a control. The attachment studies were carried out in a novel particle-coated column reactor. The saturated reactor containing glass beads, which were coated with fine mineral concentrates, provided a quantifiable surface area of mineral concentrate and maintained good fluid flow. A. ferrooxidans and Leptospirillum spp. had similar attachment characteristics. Enhanced attachment efficiency occurred with bacteria grown on sulphide minerals relative to those grown on ferrous sulphate in an ore-free environment. Selective attachment to sulphide minerals relative to gangue materials occurred, with mineral adapted cultures attaching to the minerals more efficiently than ferrous grown cultures. Mineral-adapted cultures showed highest levels of attachment to pyrite (74% and 79% attachment for A. ferrooxidans and L. ferriphilum, respectively). This was followed by attachment of mineral-adapted cultures to chalcopyrite (63% and 58% for A. ferrooxidans and L. ferriphilum, respectively). A. ferrooxidans and L. ferriphilum exhibited lower levels of attachment to low-grade ore and quartz relative to the sulphide minerals.

  6. 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.

  7. 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.

  8. 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.

  9. Insights into the Quorum Sensing Regulon of the Acidophilic Acidithiobacillus ferrooxidans Revealed by Transcriptomic in the Presence of an Acyl Homoserine Lactone Superagonist Analog.

    Science.gov (United States)

    Mamani, Sigde; Moinier, Danielle; Denis, Yann; Soulère, Laurent; Queneau, Yves; Talla, Emmanuel; Bonnefoy, Violaine; Guiliani, Nicolas

    2016-01-01

    While a functional quorum sensing system has been identified in the acidophilic chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 23270(T) and shown to modulate cell adhesion to solid substrates, nothing is known about the genes it regulates. To address the question of how quorum sensing controls biofilm formation in A. ferrooxidans (T), the transcriptome of this organism in conditions in which quorum sensing response is stimulated by a synthetic superagonist AHL (N-acyl homoserine lactones) analog has been studied. First, the effect on biofilm formation of a synthetic AHL tetrazolic analog, tetrazole 9c, known for its agonistic QS activity, was assessed by fluorescence and electron microscopy. A fast adherence of A. ferrooxidans (T) cells on sulfur coupons was observed. Then, tetrazole 9c was used in DNA microarray experiments that allowed the identification of genes regulated by quorum sensing signaling, and more particularly, those involved in early biofilm formation. Interestingly, afeI gene, encoding the AHL synthase, but not the A. ferrooxidans quorum sensing transcriptional regulator AfeR encoding gene, was shown to be regulated by quorum sensing. Data indicated that quorum sensing network represents at least 4.5% (141 genes) of the ATCC 23270(T) genome of which 42.5% (60 genes) are related to biofilm formation. Finally, AfeR was shown to bind specifically to the regulatory region of the afeI gene at the level of the palindromic sequence predicted to be the AfeR binding site. Our results give new insights on the response of A. ferrooxidans to quorum sensing and on biofilm biogenesis.

  10. 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.

  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. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    OpenAIRE

    Stefanie eMangold; Jorge eValdés; Jorge eValdés; David eHolmes; David eHolmes; Mark eDopson

    2011-01-01

    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...

  13. Sulfur Metabolism in the Extreme Acidophile Acidithiobacillus Caldus

    OpenAIRE

    Mangold, Stefanie; Valdés, Jorge; Holmes, David S.; Dopson, Mark

    2011-01-01

    Given the challenges to life at low pH, an analysis of inorganic sulfur compound (ISC) oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of ISCs. 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...

  14. 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)

  15. 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.

  16. 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.

  17. Oxidation study of the synthetic sulfides molybdenite (MoS2) and covellite (CuS) by acidithiobacillus ferrooxidants using respirometric experiments

    International Nuclear Information System (INIS)

    Francisco Junior, Wilmo E.; Universidade Estadual Paulista; Bevilaqua, Denise; Garcia Junior, Oswaldo

    2009-01-01

    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 3+ did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations. (author)

  18. Effect of metal sulfide pulp density on gene expression of electron transporters in Acidithiobacillus sp. FJ2.

    Science.gov (United States)

    Fatemi, Faezeh; Miri, Saba; Jahani, Samaneh

    2017-05-01

    In Acidithiobacillus ferrooxidans, one of the most important bioleaching bacterial species, the proteins encoded by the rus operon are involved in the electron transfer from Fe 2+ to O 2 . To obtain further knowledge about the mechanism(s) involved in the adaptive responses of the bacteria to growth on the different uranium ore pulp densities, we analyzed the expression of the four genes from the rus operon by real-time PCR, when Acidithiobacillus sp. FJ2 was grown in the presence of different uranium concentrations. The uranium bioleaching results showed the inhibitory effects of the metal pulp densities on the oxidation activity of the bacteria which can affect Eh, pH, Fe oxidation and uranium extractions. Gene expression analysis indicated that Acidithiobacillus sp. FJ2 tries to survive in the stress with increasing in the expression levels of cyc2, cyc1, rus and coxB, but the metal toxicity has a negative effect on the gene expression in different pulp densities. These results indicated that Acidithiobacillus sp. FJ2 could leach the uranium even in high pulp density (50%) by modulation in rus operon gene responses.

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

    African Journals Online (AJOL)

    Optimal sulphuric acid production using Acidithiobacillus caldus (DSM 8584): Bioprocess design for application in ion-exchange. ... Secondly, after 80% (v/v) moisture loss from the recovered biological H2SO4 titres, the acid solution was used for the recovery of nuclear grade lithium 7 (7Li+) from a degraded resin, ...

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

    African Journals Online (AJOL)

    Acidithiobacillus caldus , Leptospirillum spp., Ferroplasma spp. and Sulphobacillus spp. mixed strains for use in cobalt and copper removal from water. ... Such findings suggest that if optimal conditions for biosorption of the metals by micro-organisms are achieved, this should afford a cost-effective method of removing metal ...

  1. Growth of Thiobacillus ferrooxidans on elemental sulfur

    International Nuclear Information System (INIS)

    Espejo, R.T.; Romero, P.

    1987-01-01

    Growth kinetics of Thiobacillus ferrooxidans in batch cultures, containing prills of elementary sulfur as the sole energy source, were studied by measuring the incorporation of radioactive phosphorus in free and adsorbed bacteria. The data obtained indicate an initial exponential growth of the attached bacteria until saturation of the susceptible surface was reached, followed by a linear release of free bacteria due to successive replication of a constant number of adsorbed bacteria. These adsorbed bacteria could continue replication provided the colonized prills were transferred to fresh medium each time the stationary phase was reached. The bacteria released from the prills were unable to multiply, and in the medium employed they lost viability with a half-live of 3.5 days. The spreading of the progeny on the surface was followed by staining the bacteria on the prills with crystal violet; this spreading was not uniform but seemed to proceed through distortions present in the surface. The specific growth rate of T. ferrooxidans ATCC 19859 was about 0.5 day -1 , both before and after saturation of the sulfur surface. The growth of adsorbed and free bacteria in medium containing both ferrous iron and elementary sulfur indicated that T. ferrooxidans can simultaneously utilize both energy sources

  2. Evidence of biogenic corrosion of titanium after exposure to a continuous culture of thiobacillus ferrooxidans grown in thiosulfate medium

    International Nuclear Information System (INIS)

    Horn, J M; Martin, S I; Masterson, B

    2000-01-01

    Experiments were undertaken to evaluate extreme conditions under which candidate materials intended for use in a proposed nuclear waste repository might be susceptible to corrosion by endogenous microorganisms. Thiobucillus ferrooxidans, a sulfur-oxidizing bacterium, was grown in continuous culture using thiosulfate as an energy source; thiosulfate is oxidized to sulfate as a metabolic endproduct by this organism. Culture conditions were optimized to produce a high-density, metabolically active culture throughout a period of long term incubation in the presence of Alloy 22 (a high nickel-based alloy) and Titanium grade 7 (Tigr7) material coupons. After seven months incubation under these conditions, material coupons were withdrawn and analyzed by high resolution microscopy and energy dispersive x-ray analyses. Alloy 22 coupons showed no detectable signs of corrosion. Tigr7, however, demonstrated distinct roughening of the coupon surface, and [presumably solubilized and precipitated] titanium was detected on Alloy 22 coupons incubated in the same T. ferrooxiduns culture vessel. Control coupons of these materials incubated in sterile thiosulfate medium did not demonstrate any signs of corrosion, thus showing that observed corrosive effects were due to the T. ferrooxidans metabolic activities. T. ferrooxidans intermediates of thiosulfate oxidation or sulfate may have caused the corrosive effects observed on Tigr7

  3. 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.

  4. Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach

    OpenAIRE

    Bordron, P.; Latorre, M.; Cortés, M.; González, M.; Thiele, S.; Siegel, A.; Maass, A.; Eveillard, D.

    2016-01-01

    Abstract Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidan...

  5. 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

  6. Acidithiobacillus caldus sulfur oxidation model based on transcriptome analysis between the wild type and sulfur oxygenase reductase defective mutant.

    Directory of Open Access Journals (Sweden)

    Linxu Chen

    Full Text Available Acidithiobacillus caldus (A. caldus is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox system (omitting SoxCD, non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR. The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system.An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor was created and its growth abilities were measured in media using elemental sulfur (S(0 and tetrathionate (K(2S(4O(6 as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR of the wild type and the Δsor mutant in S(0 and K(2S(4O(6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO and heterodisulfide reductase (HDR, the truncated Sox pathway, and the S(4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media.An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

  7. Acidithiobacillus caldus sulfur oxidation model based on transcriptome analysis between the wild type and sulfur oxygenase reductase defective mutant.

    Science.gov (United States)

    Chen, Linxu; Ren, Yilin; Lin, Jianqun; Liu, Xiangmei; Pang, Xin; Lin, Jianqiang

    2012-01-01

    Acidithiobacillus caldus (A. caldus) is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs) for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox) system (omitting SoxCD), non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR). The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system. An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor) was created and its growth abilities were measured in media using elemental sulfur (S(0)) and tetrathionate (K(2)S(4)O(6)) as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR) of the wild type and the Δsor mutant in S(0) and K(2)S(4)O(6) media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO) and heterodisulfide reductase (HDR), the truncated Sox pathway, and the S(4)I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media. An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

  8. Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

    International Nuclear Information System (INIS)

    Rouas, C.

    1988-12-01

    A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry [fr

  9. 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

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. Work within the coordinated programme on bacterial leaching of uranium ores. Immunological identification of Thiobacillus ferrooxidans and Thiobacillus thiooxidans

    International Nuclear Information System (INIS)

    Rhee, K.S.

    1978-04-01

    Little is known of the antigenic structure of Thiobacillus. In the composition of the antigens of gram negative bacteria the polysaccharide moiety endows some specificity permitting immunological identification. The report considers work on attempts to isolate the type specific component from T. thiooxidans and T ferrooxidans. The fractionation procedures presented suggest that the presence of one or a few such type specific major protein antigen fractions from both of the T. ferrooxidans and the T. thiooxidans seems to be originated from the cytoplasm of the bacteria, since it is believed that the glycoprotein fractions which was derived from the cell wall are the common antigenic fraction between the T. ferrooxidans and the T. thiooxidans, respectively. In this regard, it is of great interest that the T. ferrooxidans or the T. thiooxidans appears not to have the type-specific antigens on their LPS or polysaccharide moiety in contrast to the other gram-negative bacteria. Thus, it is strongly believed that the envelopes of these bacteria contain both glycoproteins bearing common antigenicity, since the T. ferrooxidans and the T. thiooxidans have a structually different type-specific antigen moiety according to the results polyacrylamide gel electrophoresis

  15. Whole-genome sequencing reveals novel insights into sulfur oxidation in the extremophile Acidithiobacillus thiooxidans

    OpenAIRE

    Yin, Huaqun; Zhang, Xian; Li, Xiaoqi; He, Zhili; Liang, Yili; Guo, Xue; Hu, Qi; Xiao, Yunhua; Cong, Jing; Ma, Liyuan; Niu, Jiaojiao; Liu, Xueduan

    2014-01-01

    Background Acidithiobacillus thiooxidans (A. thiooxidans), a chemolithoautotrophic extremophile, is widely used in the industrial recovery of copper (bioleaching or biomining). The organism grows and survives by autotrophically utilizing energy derived from the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs). However, the lack of genetic manipulation systems has restricted our exploration of its physiology. With the development of high-throughput sequencing techno...

  16. Draft Genome Sequence of the Extremophile Acidithiobacillus thiooxidans A01, Isolated from the Wastewater of a Coal Dump.

    Science.gov (United States)

    Yin, Huaqun; Zhang, Xian; Liang, Yili; Xiao, Yunhua; Niu, Jiaojiao; Liu, Xueduan

    2014-04-03

    The draft genome of Acidithiobacillus thiooxidans A01 contains 3,820,158 bp, with a G+C content of 53.08% and 3,660 predicted coding sequences (CDSs). The bacterium contains a series of specific genes involved in the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs).

  17. Gene function analysis in environmental isolates: The nif regulon of the strict iron oxidizing bacterium Leptospirillum ferrooxidans

    Science.gov (United States)

    Parro, Víctor; Moreno-Paz, Mercedes

    2003-01-01

    A random genomic library from an environmental isolate of the Gram-negative bacterium Leptospirillum ferrooxidans has been printed on a microarray. Gene expression analysis was carried out with total RNA extracted from L. ferrooxidans cultures in the presence or absence of ammonium as nitrogen source under aerobic conditions. Although practically nothing is known about the genome sequence of this bacterium, this approach allowed us the selection and sequencing of only those clones bearing genes that showed an altered expression pattern. By sequence comparison, we have identified most of the genes of nitrogen fixation regulon in L. ferrooxidans, like the nifHDKENX operon, encoding the structural components of Mo-Fe nitrogenase; nifSU-hesB-hscBA-fdx operon, for Fe-S cluster assembly; the amtB gene (ammonium transporter); modA (molybdenum ABC type transporter); some regulatory genes like ntrC, nifA (the specific activator of nif genes); or two glnB-like genes (encoding the PII regulatory protein). Our results show that shotgun DNA microarrays are very powerful tools to accomplish gene expression studies with environmental bacteria whose genome sequence is still unknown, avoiding the time and effort necessary for whole genome sequencing projects. PMID:12808145

  18. 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...

  19. 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.

  20. Whole-genome sequencing reveals novel insights into sulfur oxidation in the extremophile Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Yin, Huaqun; Zhang, Xian; Li, Xiaoqi; He, Zhili; Liang, Yili; Guo, Xue; Hu, Qi; Xiao, Yunhua; Cong, Jing; Ma, Liyuan; Niu, Jiaojiao; Liu, Xueduan

    2014-07-04

    Acidithiobacillus thiooxidans (A. thiooxidans), a chemolithoautotrophic extremophile, is widely used in the industrial recovery of copper (bioleaching or biomining). The organism grows and survives by autotrophically utilizing energy derived from the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs). However, the lack of genetic manipulation systems has restricted our exploration of its physiology. With the development of high-throughput sequencing technology, the whole genome sequence analysis of A. thiooxidans has allowed preliminary models to be built for genes/enzymes involved in key energy pathways like sulfur oxidation. The genome of A. thiooxidans A01 was sequenced and annotated. It contains key sulfur oxidation enzymes involved in the oxidation of elemental sulfur and RISCs, such as sulfur dioxygenase (SDO), sulfide quinone reductase (SQR), thiosulfate:quinone oxidoreductase (TQO), tetrathionate hydrolase (TetH), sulfur oxidizing protein (Sox) system and their associated electron transport components. Also, the sulfur oxygenase reductase (SOR) gene was detected in the draft genome sequence of A. thiooxidans A01, and multiple sequence alignment was performed to explore the function of groups of related protein sequences. In addition, another putative pathway was found in the cytoplasm of A. thiooxidans, which catalyzes sulfite to sulfate as the final product by phosphoadenosine phosphosulfate (PAPS) reductase and adenylylsulfate (APS) kinase. This differs from its closest relative Acidithiobacillus caldus, which is performed by sulfate adenylyltransferase (SAT). Furthermore, real-time quantitative PCR analysis showed that most of sulfur oxidation genes were more strongly expressed in the S0 medium than that in the Na2S2O3 medium at the mid-log phase. Sulfur oxidation model of A. thiooxidans A01 has been constructed based on previous studies from other sulfur oxidizing strains and its genome sequence analyses, providing insights

  1. EXAFS investigation of uranium(6) complexes formed at Acidithiobacillus ferro oxidans types

    International Nuclear Information System (INIS)

    Merroun, M.; Reich, T.; Hennig, Ch.; Selenska-Pobell, S.

    2002-01-01

    Mining activities have brought excessive amounts of uranium into the environment. In uranium deposits a number of acidophilic chemo-litho-autotrophic bacteria have been identified which are able to oxidize sulphide minerals, elemental sulphur, ferrous iron and also (in the presence of uranium mineral) U(IV). In particular, the interaction of one representative of the group Acidithiobacillus ferro oxidans (new designation of Thiobacillus ferro oxidans) with uranium has been investigated. Uranium(VI) complex formations at the surfaces of Acidithiobacillus ferro oxidans were studied using uranium L III -edge extended X-ray absorption fine structure (EXAFS) spectroscopy. In all samples uranium is co-ordinated by two axial oxygen atoms (O ax ) at a distance of 1.77-1.78 angstrom. The average distance between uranium and the equatorial oxygen atoms (O eq ) is 2.35 angstrom. The co-ordination number for O eq is 5-6. In comparison to the uranium crystal structure data, the U-O eq distance indicates a co-ordination number of the equatorial oxygen of 5. Within the experimental error, there are no differences in the U-O bond distances between samples from the three types of A. ferro oxidans investigated. The fit to the EXAFS data of samples measured as wet pastes gave the same results as for dried samples. No significant structural differences were observed for the uranium complexes formed by the eco-types of A. ferro oxidans. However, the EXAFS spectra do indicate a formation of uranium complexes which are different from those formed by Bacilli where the bond length of 2.28 angstrom indicates a co-ordination number of 4 for the equatorial oxygen atoms. (authors)

  2. Amplification of ribulose biphosphate carboxylase/oxygenase large subunit (RuBisCO LSU) gene fragments from Thiobacillus ferrooxidans and a moderate thermophile using polymerase chain reaction.

    Science.gov (United States)

    Holden, P J; Brown, R W

    1993-07-01

    Southern blot analysis of DNA from an iron-oxidising moderate thermophile NMW-6 and from Thiobacillus ferrooxidans strain TFI-35 demonstrated sequences homologous to the RuBisCO LSU gene of Synechococcus. DNA fragments (457 bp) encoding part of the RuBisCO LSU gene (amino acids 73-200) were amplified from the genomic DNA of Thiobacillus ferrooxidans and the moderate thermophile NMW-6 using the polymerase chain reaction (PCR) technique (Saiki et al. (1985) Science 233, 1350-1354). A comparison with the LSU sequences from T. ferrooxidans, Alcaligenes eutrophus, Chromatium vinosum, Synechococcus and Spinacea oleracea, which all have RuBisCOs with a hexadecameric structure, showed that the RuBisCO LSU gene sequence from NMW-6 appeared to be most closely related to that of the hydrogen bacterium A. eutrophus which showed 71.9% homology at the amino acid level. Despite its physiological similarity, T. ferrooxidans showed only 64.1% homology to the amino acid sequence from NMW-6 and had the lowest DNA homology (60.9%) of the hexadecameric type RuBisCOs. In the region sequenced, T. ferrooxidans and the RuBisCOs of the phototrophs C. vinosum, Synechococcus and S. oleracea, had 17 residues that were completely conserved which were substituted in both NMW-6 and A. eutrophus, 11 of these being identical substitutions. Comparison of the nucleotide and derived amino acid sequences of the RuBisCO LSU fragment from T. ferrooxidans with other RuBisCO sequences indicated a closer relationship to the hexadecameric type LSU genes of photosynthetic origin than to that of A. eutrophus. The T. ferrooxidans amino acid sequence showed 93.8%, 78.9% and 77.3% homology, respectively, to the C. vinosum, Synechococcus and S. oleracea (spinach) sequences but only 56.2% to A. eutrophus. The DNA sequence from Rhodospirillum rubrum, which has the atypical large subunit dimer RuBisCO structure with no small subunit, showed 39.2% and 42.7% homology, respectively, with the sequences of NMW-6 and T

  3. Selective Attachment of Leptospirillum ferrooxidans for Separation of Chalcopyrite and Pyrite through Bio-Flotation

    Directory of Open Access Journals (Sweden)

    Belinda Bleeze

    2018-02-01

    Full Text Available The replacement of depressants used in sulfide mineral beneficiation, with bacteria and their metabolites, promises to reduce the environmental impact left by the mining industry. In this study, the attachment of Leptospirillum ferrooxidans, L.f, to chalcopyrite and pyrite was investigated through Scanning Electron Microscopy (SEM. The impact of selective attachment, bacterial growth conditions, and extracellular polymeric substances (EPS was investigated through bio-flotation. L.f exhibits selective attachment to pyrite between 0 h and 168 h exposure via an indirect contact mechanism. Separation of chalcopyrite from pyrite was achieved through exposing the minerals for 72 h with an L.f culture grown on either HH media, chalcopyrite, or pyrite. The results produced 80.4, 43.4, and 47.4% recovery of chalcopyrite, respectively. However, EPS supernatant extracted from L.f grown on chalcopyrite, conditioned for 48 h, provided the best separation efficiency by the selective depression of pyrite resulting in 95.8% Cu recovery. Polysaccharide-rich EPS selectively attaches to pyrite within 48 h, depressing its floatability and ensuring successful separation with a PIPX collector.

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

    OpenAIRE

    OLGA CVETKOVIC; DRAGOMIR VITOROVIC; SNEZANA SPASIC; VALERIJA MATIC; VESNA DRAGUTINOVIC; MIROSLAV M. VRVIC

    2003-01-01

    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 de...

  5. Adenosine 5'-triphosphate formation in Thiobacillus ferrooxidans vesicles by H+ ion gradients comparable to those of environmental conditions.

    OpenAIRE

    Apel, W A; Dugan, P R; Tuttle, J H

    1980-01-01

    Vesicles prepared from iron-grown Thiobacillus ferrooxidans, and subsequently loaded with adenosine 5'-diphosphate and inorganic phosphate, produced adenosine 5'-triphosphate when subjected to H+ gradients comparable to those in the cells' normal environment (i.e., an internal pH in the range of 6.0 to 8.0 with an optimum of 7.0 to 7.8 and an external pH in the range of 2.1 to 4.1 with an optimum of 2.8). Nigericin, dicyclohexylcarbodiimide, and pentachlorophenol decreased adenosine 5'-tripho...

  6. 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.

  7. 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.

  8. Growth of Leptospirillum ferriphilum in sulfur medium in co-culture with Acidithiobacillus caldus.

    Science.gov (United States)

    Smith, Sarah L; Johnson, D Barrie

    2018-03-01

    Leptospirillum ferriphilum and Acidithiobacillus caldus are both thermotolerant acidophilic bacteria that frequently co-exist in natural and man-made environments, such as biomining sites. Both are aerobic chemolithotrophs; L. ferriphilum is known only to use ferrous iron as electron donor, while A. caldus can use zero-valent and reduced sulfur, and also hydrogen, as electron donors. It has recently been demonstrated that A. caldus reduces ferric iron to ferrous when grown aerobically on sulfur. Experiments were carried out which demonstrated that this allowed L. ferriphilum to be sustained for protracted periods in media containing very little soluble iron, implying that dynamic cycling of iron occurred in aerobic mixed cultures of these two bacteria. In contrast, numbers of viable L. ferriphilum rapidly declined in mixed cultures that did not contain sulfur. Data also indicated that growth of A. caldus was partially inhibited in the presence of L. ferriphilum. This was shown to be due to greater sensitivity of the sulfur-oxidizer to ferric than to ferrous iron, and to highly positive redox potentials, which are characteristic of cultures containing Leptospirillum spp. The implications of these results in the microbial ecology of extremely acidic environments and in commercial bioprocessing applications are discussed.

  9. 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.

  10. Metabolism

    Science.gov (United States)

    ... functions: Anabolism (uh-NAB-uh-liz-um), or constructive metabolism, is all about building and storing. It ... in infants and young children. Hypothyroidism slows body processes and causes fatigue (tiredness), slow heart rate, excessive ...

  11. Metabolism

    Science.gov (United States)

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... acid phenylalanine, needed for normal growth and protein production). Inborn errors of metabolism can sometimes lead to ...

  12. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans

    International Nuclear Information System (INIS)

    NareshKumar, R.; Nagendran, R.

    2008-01-01

    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application

  13. 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.

  14. 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.

  15. Phosphate Favors the Biosynthesis of CdS Quantum Dots inAcidithiobacillus thiooxidansATCC 19703 by Improving Metal Uptake and Tolerance.

    Science.gov (United States)

    Ulloa, Giovanni; Quezada, Carolina P; Araneda, Mabel; Escobar, Blanca; Fuentes, Edwar; Álvarez, Sergio A; Castro, Matías; Bruna, Nicolás; Espinoza-González, Rodrigo; Bravo, Denisse; Pérez-Donoso, José M

    2018-01-01

    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.

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

    Science.gov (United States)

    Ulloa, Giovanni; Quezada, Carolina P.; Araneda, Mabel; Escobar, Blanca; Fuentes, Edwar; Álvarez, Sergio A.; Castro, Matías; Bruna, Nicolás; Espinoza-González, Rodrigo; Bravo, Denisse; Pérez-Donoso, José M.

    2018-01-01

    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. PMID:29515535

  17. 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.

  18. 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

  19. Arsenic bioleaching in medical realgar ore and arsenic- bearing ...

    African Journals Online (AJOL)

    Conclusion: Arsenic leaching ratio of realgar and refractory gold ore can be enhanced significantly in the presence of arsenic-adapted mesophilic acidophiles. Keywords: Adaptation, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Realgar, Arsenic- bearing refractory gold ore, Arsenic leaching ratio. Tropical ...

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

    African Journals Online (AJOL)

    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 ...

  1. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Directory of Open Access Journals (Sweden)

    Matías Castro

    Full Text Available An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs and degraded by phosphodiesterases (PDEs. We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319 that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process.

  2. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Science.gov (United States)

    Castro, Matías; Deane, Shelly M; Ruiz, Lina; Rawlings, Douglas E; Guiliani, Nicolas

    2015-01-01

    An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs) and degraded by phosphodiesterases (PDEs). We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319) that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process.

  3. 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.

  4. Influence of organics and silica on Fe(II) oxidation rates and cell-mineral aggregate formation by the green-sulfur Fe(II)-oxidizing bacterium Chlorobium ferrooxidans KoFox - Implications for Fe(II) oxidation in ancient oceans

    Science.gov (United States)

    Gauger, Tina; Byrne, James M.; Konhauser, Kurt O.; Obst, Martin; Crowe, Sean; Kappler, Andreas

    2016-06-01

    Most studies on microbial phototrophic Fe(II) oxidation (photoferrotrophy) have focused on purple bacteria, but recent evidence points to the importance of green-sulfur bacteria (GSB). Their recovery from modern ferruginous environments suggests that these photoferrotrophs can offer insights into how their ancient counterparts grew in Archean oceans at the time of banded iron formation (BIF) deposition. It is unknown, however, how Fe(II) oxidation rates, cell-mineral aggregate formation, and Fe-mineralogy vary under environmental conditions reminiscent of the geological past. To address this, we studied the Fe(II)-oxidizer Chlorobium ferrooxidans KoFox, a GSB living in co-culture with the heterotrophic Geospirillum strain KoFum. We investigated the mineralogy of Fe(III) metabolic products at low/high light intensity, and in the presence of dissolved silica and/or fumarate. Silica and fumarate influenced the crystallinity and particle size of the produced Fe(III) minerals. The presence of silica also enhanced Fe(II) oxidation rates, especially at high light intensities, potentially by lowering Fe(II)-toxicity to the cells. Electron microscopic imaging showed no encrustation of either KoFox or KoFum cells with Fe(III)-minerals, though weak associations were observed suggesting co-sedimentation of Fe(III) with at least some biomass via these aggregates, which could support diagenetic Fe(III)-reduction. Given that GSB are presumably one of the most ancient photosynthetic organisms, and pre-date cyanobacteria, our findings, on the one hand, strengthen arguments for photoferrotrophic activity as a likely mechanism for BIF deposition on a predominantly anoxic early Earth, but, on the other hand, also suggest that preservation of remnants of Fe(II)-oxidizing GSB as microfossils in the rock record is unlikely.

  5. Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach.

    Science.gov (United States)

    Bordron, Philippe; Latorre, Mauricio; Cortés, Maria-Paz; González, Mauricio; Thiele, Sven; Siegel, Anne; Maass, Alejandro; Eveillard, Damien

    2016-02-01

    Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans, we first reconstructed a global metabolic network. Next, using a parsimony assumption, we deciphered sets of genes, called Sets from Genome Segments (SGS), that (1) are close on their respective genomes, (2) take an active part in metabolic pathways and (3) whose associated metabolic reactions are also closely connected within metabolic networks. Overall, this SGS paradigm depicts genomic functional units that emphasize respective roles of bacterial strains to catalyze metabolic pathways and environmental processes. Our analysis suggested that only few functional metabolic genes are horizontally transferred within the consortium and that no single bacterial strain can accomplish by itself the whole copper bioleaching. The use of SGS pinpoints a functional compartmentalization among the investigated species and exhibits putative bacterial interactions necessary for promoting these pathways. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  6. 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 done on ... and liver. There are two types: basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). The BMP ...

  7. 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)

  8. Metabolic Syndrome

    Science.gov (United States)

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

  9. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

    Chemistry of Drug Metabolism. Drug metabolism is a chemical process, where enzymes play a crucial role in the conversion of one chemical species to another. The major family of enzymes associated with these metabolic reactions is the cytochrome P450 family. The structural features and functional activity of these ...

  10. 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...

  11. 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 ...

  12. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

    Drug metabolism may be defined as the biochemical modifica- tion of one chemical form to another, occurring usually through ..... Endogenous. Enzyme. Drugs. Cofactor. Glucuronidation. UDP glucoronic. UDP-. Chloramphenicol, acid glucuronosyltransferase morphine, paracetamol, salicylic acid, fenoprofen, desipramine,.

  13. Metabolic Myopathies.

    Science.gov (United States)

    Tarnopolsky, Mark A

    2016-12-01

    Metabolic myopathies are genetic disorders that impair intermediary metabolism in skeletal muscle. Impairments in glycolysis/glycogenolysis (glycogen-storage disease), fatty acid transport and oxidation (fatty acid oxidation defects), and the mitochondrial respiratory chain (mitochondrial myopathies) represent the majority of known defects. The purpose of this review is to develop a diagnostic and treatment algorithm for the metabolic myopathies. The metabolic myopathies can present in the neonatal and infant period as part of more systemic involvement with hypotonia, hypoglycemia, and encephalopathy; however, most cases present in childhood or in adulthood with exercise intolerance (often with rhabdomyolysis) and weakness. The glycogen-storage diseases present during brief bouts of high-intensity exercise, whereas fatty acid oxidation defects and mitochondrial myopathies present during a long-duration/low-intensity endurance-type activity or during fasting or another metabolically stressful event (eg, surgery, fever). The clinical examination is often normal between acute events, and evaluation involves exercise testing, blood testing (creatine kinase, acylcarnitine profile, lactate, amino acids), urine organic acids (ketones, dicarboxylic acids, 3-methylglutaconic acid), muscle biopsy (histology, ultrastructure, enzyme testing), MRI/spectroscopy, and targeted or untargeted genetic testing. Accurate and early identification of metabolic myopathies can lead to therapeutic interventions with lifestyle and nutritional modification, cofactor treatment, and rapid treatment of rhabdomyolysis.

  14. Animal metabolism

    International Nuclear Information System (INIS)

    Walburg, H.E.

    1977-01-01

    Studies on placental transport included the following: clearance of tritiated water as a baseline measurement for transport of materials across perfused placentas; transport of organic and inorganic mercury across the perfused placenta of the guinea pig in late gestation; and transport of cadmium across the perfused placenta of the guinea pig in late gestation. Studies on cadmium absorption and metabolism included the following: intestinal absorption and retention of cadmium in neonatal rats; uptake and distribution of an oral dose of cadmium in postweanling male and female, iron-deficient and normal rats; postnatal viability and growth in rat pups after oral cadmium administration during gestation; and the effect of calcium and phosphorus on the absorption and toxicity of cadmium. Studies on gastrointestinal absorption and mineral metabolism included: uptake and distribution of orally administered plutonium complex compounds in male mice; gastrointestinal absorption of 144 Ce in the newborn mouse, rat, and pig; and gastrointestinal absorption of 95 Nb by rats of different ages. Studies on iodine metabolism included the following: influence of thyroid status and thiocyanate on iodine metabolism in the bovine; effects of simulated fallout radiation on iodine metabolism in dairy cattle; and effects of feeding iodine binding agents on iodine metabolism in the calf

  15. 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 ...

  16. [Metabolic myopathies].

    Science.gov (United States)

    Papazian, Óscar; Rivas-Chacón, Rafael

    2013-09-06

    To review the metabolic myopathies manifested only by crisis of myalgias, cramps and rigidity of the muscles with decreased voluntary contractions and normal inter crisis neurologic examination in children and adolescents. These metabolic myopathies are autosomic recessive inherited enzymatic deficiencies of the carbohydrates and lipids metabolisms. The end result is a reduction of intra muscle adenosine triphosphate, mainly through mitochondrial oxidative phosphorylation, with decrease of available energy for muscle contraction. The one secondary to carbohydrates intra muscle metabolism disorders are triggered by high intensity brief (fatty acids metabolism disorders are triggered by low intensity prolonged (> 10 min) exercises. The conditions in the first group in order of decreasing frequency are the deficiencies of myophosforilase (GSD V), muscle phosphofructokinase (GSD VII), phosphoglycerate mutase 1 (GSD X) and beta enolase (GSD XIII). The conditions in the second group in order of decreasing frequency are the deficiencies of carnitine palmitoyl transferase II and very long chain acyl CoA dehydrogenase. The differential characteristics of patients in each group and within each group will allow to make the initial presumptive clinical diagnosis in the majority and then to order only the necessary tests to achieve the final diagnosis. Treatment during the crisis includes hydration, glucose and alkalinization of urine if myoglobin in blood and urine are elevated. Prevention includes avoiding exercise which may induce the crisis and fasting. The prognosis is good with the exception of rare cases of acute renal failure due to hipermyoglobinemia because of severe rabdomyolisis.

  17. 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.

  18. Environmental transcriptome analysis reveals physiological differences between biofilm and planktonic modes of life of the iron oxidizing bacteria Leptospirillum spp. in their natural microbial community

    Directory of Open Access Journals (Sweden)

    Parro Víctor

    2010-06-01

    Full Text Available Abstract Background Extreme acidic environments are characterized by their high metal content and lack of nutrients (oligotrophy. Macroscopic biofilms and filaments usually grow on the water-air interface or under the stream attached to solid substrates (streamers. In the Río Tinto (Spain, brown filaments develop under the water stream where the Gram-negative iron-oxidizing bacteria Leptospirillum spp. (L. ferrooxidans and L. ferriphilum and Acidithiobacillus ferrooxidans are abundant. These microorganisms play a critical role in bioleaching processes for industrial (biominery and environmental applications (acid mine drainage, bioremediation. The aim of this study was to investigate the physiological differences between the free living (planktonic and the sessile (biofilm associated lifestyles of Leptospirillum spp. as part of its natural extremely acidophilic community. Results Total RNA extracted from environmental samples was used to determine the composition of the metabolically active members of the microbial community and then to compare the biofilm and planktonic environmental transcriptomes by hybridizing to a genomic microarray of L. ferrooxidans. Genes up-regulated in the filamentous biofilm are involved in cellular functions related to biofilm formation and maintenance, such as: motility and quorum sensing (mqsR, cheAY, fliA, motAB, synthesis of cell wall structures (lnt, murA, murB, specific proteases (clpX/clpP, stress response chaperons (clpB, clpC, grpE-dnaKJ, groESL, etc. Additionally, genes involved in mixed acid fermentation (poxB, ackA were up-regulated in the biofilm. This result, together with the presence of small organic acids like acetate and formate (1.36 mM and 0.06 mM respectively in the acidic (pH 1.8 water stream, suggests that either L. ferrooxidans or other member of the microbial community are producing acetate in the acidophilic biofilm under microaerophilic conditions. Conclusions Our results indicate that the

  19. Metabolic Engineering

    Indian Academy of Sciences (India)

    IAS Admin

    and in vitro to be able to alter properties of the encoded enzyme, and (6) assemble an array of genes for their expression inside the host cell. Although bacteria and yeast are the pioneering hosts for metabolic engineering, other organisms such as fungi, animal as well as plant cells are also used nowadays for similar experi ...

  20. Metabolic Engineering

    Indian Academy of Sciences (India)

    IAS Admin

    Metabolic engineering is a process for modulating the me- tabolism of the organisms so as to produce the required amounts of the desired metabolite through genetic manipula- tions. Considering its advantages over the other chemical synthesis routes, this area of biotechnology is likely to revolu- tionize the way in which ...

  1. Metabolic syndrome

    Science.gov (United States)

    ... gov/pubmed/26718656 . Ruderman NB, Shulman GI. Metabolic syndrome. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric . 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 43. Review ... NIH MedlinePlus Magazine Read more Health ...

  2. Metabolic Disorders

    Science.gov (United States)

    Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's ...

  3. Leaching of Copper Ore by Thiobacillus Ferrooxidans.

    Science.gov (United States)

    Lennox, John; Biaha, Thomas

    1991-01-01

    A quantitative laboratory exercise based upon the procedures copper manufacturers employ to increase copper production is described. The role of chemoautotrophic microorganisms in biogeologic process is emphasized. Safety considerations when working with bacteria are included. (KR)

  4. Metabolic alkalosis.

    Science.gov (United States)

    Khanna, A; Kurtzman, N A

    2006-01-01

    Metabolic alkalosis is a primary pathophysiologic event characterized by the gain of bicarbonate or the loss of nonvolatile acid from extracellular fluid. The kidney preserves normal acid-base balance by two mechanisms: bicarbonate reclamation mainly in the proximal tubule and bicarbonate generation predominantly in the distal nephron. Bicarbonate reclamation is mediated mainly by a Na-H antiporter and to a smaller extent by the H-ATPase. The principal factors affecting HCO 3 reabsorption include effective arterial blood volume, glomerular filtration rate, chloride, and potassium. Bicarbonate regeneration is primarily affected by distal Na delivery and reabsorption, aldosterone, arterial pH, and arterial pCO2. To generate metabolic alkalosis, either a gain of base or a loss of acid, must occur. The loss of acid may be via the GI tract or by the kidney. Excess base may be gained by oral or parenteral HCO 3 administration or by lactate, acetate, or citrate administration. Factors that help maintain metabolic alkalosis include decreased glomerular filtration rate (GFR), volume contraction, hypokalemia, hypochloremia, and aldosterone excess. Clinical states associated with metabolic alkalosis are vomiting, mineralocorticoid excess, the adrenogenital syndrome, licorice ingestion, diuretic administration, and Bartter's and Gitelma's Syndromes. The effects of metabolic alkalosis on the body are varied and include effects on the central nervous system, myocardium, skeletal muscle, and the liver. Treatment of this disorder is simple, once the pathophysiology of the cause is delineated. Therapy consists of reversing the contributory factors promoting alkalosis and in severe cases, administration of carbonic anhydrase inhibitors, acid infusion, and low bicarbonate dialysis.

  5. Insights into the Structure and Metabolic Function of Microbes That Shape Pelagic Iron-Rich Aggregates (“Iron Snow”)

    Science.gov (United States)

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B.; Neu, Thomas R.; Hettich, Robert L.

    2013-01-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates (“iron snow”) at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 108 copies g (dry weight)−1 in the acidic central lake basin (pH 3.3) to 4.0 × 1010 copies g (dry weight)−1 in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies. PMID:23645202

  6. Insights into the structure and metabolic function of microbes that shape pelagic iron-rich aggregates ("iron snow").

    Science.gov (United States)

    Lu, Shipeng; Chourey, Karuna; Reiche, Marco; Nietzsche, Sandor; Shah, Manesh B; Neu, Thomas R; Hettich, Robert L; Küsel, Kirsten

    2013-07-01

    Microbial ferrous iron [Fe(II)] oxidation leads to the formation of iron-rich macroscopic aggregates ("iron snow") at the redoxcline in a stratified lignite mine lake in east-central Germany. We aimed to identify the abundant Fe-oxidizing and Fe-reducing microorganisms likely to be involved in the formation and transformation of iron snow present in the redoxcline in two basins of the lake that differ in their pH values. Nucleic acid- and lipid-stained microbial cells of various morphologies detected by confocal laser scanning microscopy were homogeneously distributed in all iron snow samples. The dominant iron mineral appeared to be schwertmannite, with shorter needles in the northern than in the central basin samples. Total bacterial 16S rRNA gene copies ranged from 5.0 × 10(8) copies g (dry weight)(-1) in the acidic central lake basin (pH 3.3) to 4.0 × 10(10) copies g (dry weight)(-1) in the less acidic (pH 5.9) northern basin. Total RNA-based quantitative PCR assigned up to 61% of metabolically active microbial communities to Fe-oxidizing- and Fe-reducing-related bacteria, indicating that iron metabolism was an important metabolic strategy. Molecular identification of abundant groups suggested that iron snow surfaces were formed by chemoautotrophic iron oxidizers, such as Acidimicrobium, Ferrovum, Acidithiobacillus, Thiobacillus, and Chlorobium, in the redoxcline and were rapidly colonized by heterotrophic iron reducers, such as Acidiphilium, Albidiferax-like, and Geobacter-like groups. Metaproteomics yielded 283 different proteins from northern basin iron snow samples, and protein identification provided a glimpse into some of their in situ metabolic processes, such as primary production (CO2 fixation), respiration, motility, and survival strategies.

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

    Science.gov (United States)

    Ngom, Baba; Liang, Yili; Liu, Xueduan

    2014-01-01

    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. PMID:25478575

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

    African Journals Online (AJOL)

    conditions such as pH, temperature, time, volume and metal concentration on the efficiency of the biosorption process was ... metals by micro-organisms are achieved, this should afford a cost-effective method of removing metal species from water ..... TSEZOS M (1983) The role of chitin in uranium adsorption by Rhizopus.

  9. 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. ...

  10. Comparative genome analysis reveals metabolic versatility and environmental adaptations of Sulfobacillus thermosulfidooxidans strain ST.

    Directory of Open Access Journals (Sweden)

    Xue Guo

    Full Text Available The genus Sulfobacillus is a cohort of mildly thermophilic or thermotolerant acidophiles within the phylum Firmicutes and requires extremely acidic environments and hypersalinity for optimal growth. However, our understanding of them is still preliminary partly because few genome sequences are available. Here, the draft genome of Sulfobacillus thermosulfidooxidans strain ST was deciphered to obtain a comprehensive insight into the genetic content and to understand the cellular mechanisms necessary for its survival. Furthermore, the expressions of key genes related with iron and sulfur oxidation were verified by semi-quantitative RT-PCR analysis. The draft genome sequence of Sulfobacillus thermosulfidooxidans strain ST, which encodes 3225 predicted coding genes on a total length of 3,333,554 bp and a 48.35% G+C, revealed the high degree of heterogeneity with other Sulfobacillus species. The presence of numerous transposases, genomic islands and complete CRISPR/Cas defence systems testifies to its dynamic evolution consistent with the genome heterogeneity. As expected, S. thermosulfidooxidans encodes a suit of conserved enzymes required for the oxidation of inorganic sulfur compounds (ISCs. The model of sulfur oxidation in S. thermosulfidooxidans was proposed, which showed some different characteristics from the sulfur oxidation of Gram-negative A. ferrooxidans. Sulfur oxygenase reductase and heterodisulfide reductase were suggested to play important roles in the sulfur oxidation. Although the iron oxidation ability was observed, some key proteins cannot be identified in S. thermosulfidooxidans. Unexpectedly, a predicted sulfocyanin is proposed to transfer electrons in the iron oxidation. Furthermore, its carbon metabolism is rather flexible, can perform the transformation of pentose through the oxidative and non-oxidative pentose phosphate pathways and has the ability to take up small organic compounds. It encodes a multitude of heavy metal

  11. 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.

  12. Metabolism Disrupting Chemicals and Metabolic Disorders

    Science.gov (United States)

    Heindel, Jerrold J.; Blumberg, Bruce; Cave, Mathew; Machtinger, Ronit; Mantovani, Alberto; Mendez, Michelle A.; Nadal, Angel; Palanza, Paola; Panzica, Giancarlo; Sargis, Robert; Vandenberg, Laura N.; Saal, Frederick vom

    2016-01-01

    The recent epidemics of metabolic diseases, obesity, type 2 diabetes(T2D), liver lipid disorders and metabolic syndrome have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence that other environmental factors may contribute to the rapid increase in the incidence of these metabolic diseases. This review will examine changes to the incidence of obesity, T2D and non-alcoholic fatty liver disease (NAFLD), the contribution of genetics to these disorders and describe the role of the endocrine system in these metabolic disorders. It will then specifically focus on the role of endocrine disrupting chemicals (EDCs) in the etiology of obesity, T2D and NAFLD while finally integrating the information on EDCs on multiple metabolic disorders that could lead to metabolic syndrome. We will specifically examine evidence linking EDC exposures during critical periods of development with metabolic diseases that manifest later in life and across generations. PMID:27760374

  13. Inborn errors of metabolism

    Science.gov (United States)

    Metabolism - inborn errors of ... Bodamer OA. Approach to inborn errors of metabolism. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 205. Rezvani I, Rezvani GA. An ...

  14. 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 ...

  15. 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

  16. Investigation of metabolic encephalopathy

    African Journals Online (AJOL)

    , and. Table 1. Confirmed IMD cases associated with metabolic encephalopathy diagnosed at Red Cross Children's Hospital Metabolic Disease. Laboratory, 2006 - 2012. Name of disorder. Number of cases. Glutaric aciduria type 1 (GA1)*. 23.

  17. Neuroendocrine Regulation of Metabolism

    OpenAIRE

    Cornejo, Maria P.; Hentges, Shane T.; Maliqueo, Manuel; Coirini, Hector; Becu-Villalobos, Damasia; Elias, Carol F.

    2016-01-01

    Given the current environment in most developed countries, it is a challenge to maintain a good balance between calories consumed and calories burned, although maintenance of metabolic balance is key to good health. Therefore, understanding how metabolic regulation is achieved and how the dysregulation of metabolism affects health is an area of intense research. Most studies are focused on the hypothalamus, which is a brain area that acts as a key regulator of metabolism. Among the nuclei tha...

  18. 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.

  19. Altered metabolism in cancer

    Directory of Open Access Journals (Sweden)

    Locasale Jason W

    2010-06-01

    Full Text Available Abstract Cancer cells have different metabolic requirements from their normal counterparts. Understanding the consequences of this differential metabolism requires a detailed understanding of glucose metabolism and its relation to energy production in cancer cells. A recent study in BMC Systems Biology by Vasquez et al. developed a mathematical model to assess some features of this altered metabolism. Here, we take a broader look at the regulation of energy metabolism in cancer cells, considering their anabolic as well as catabolic needs. See research article: http://www.biomedcentral.com/1752-0509/4/58/

  20. Cancer stem cell metabolism.

    Science.gov (United States)

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

    2016-05-24

    Cancer is now viewed as a stem cell disease. There is still no consensus on the metabolic characteristics of cancer stem cells, with several studies indicating that they are mainly glycolytic and others pointing instead to mitochondrial metabolism as their principal source of energy. 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. Determining the role of cancer stem cell metabolism in carcinogenesis has become a major focus in cancer research, and substantial efforts are conducted towards discovering clinical targets.

  1. 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....

  2. 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.

  3. DREAMS of metabolism.

    Science.gov (United States)

    Soh, Keng Cher; Hatzimanikatis, Vassily

    2010-10-01

    Metabolic networks have been studied for several decades, and sophisticated computational frameworks are needed to augment experimental approaches to harness these complex networks. BNICE (Biochemical Network Integrated Computational Explorer), a computational approach for the discovery of novel biochemical pathways that is based on biochemical transformations, overcomes many of the current limitations. BNICE and similar frameworks can be used in several different areas: (i) 'Design' of novel pathways for metabolic engineering; (ii) 'Retrosynthesis' of metabolic compounds; (iii) 'Evolution' analysis between metabolic pathways of different organisms; (iv) 'Analysis' of metabolic pathways; (v) 'Mining' of omics data; and (vi) 'Selection' of targets for enzyme engineering. Here, we discuss the issues and challenges in building such frameworks as well as the gamut of applications in biotechnology, metabolic engineering and synthetic biology. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. [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.

  5. Metabolic syndrome and menopause

    OpenAIRE

    Jouyandeh, Zahra; Nayebzadeh, Farnaz; Qorbani, Mostafa; Asadi, Mojgan

    2013-01-01

    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 t...

  6. Nutrition and metabolic syndrome.

    OpenAIRE

    Albornoz López, Raúl; Pérez Rodrigo, Iciar

    2012-01-01

    The metabolic syndrome comprises a cluster of metabolic abnormalities that increase the risk for cardiovascular disease and type 2 diabetes mellitus. The exact etiology is unclear, although it is known thatthere is a complex interaction between genetic, metabolic and environmental factors. Among the environmental factors, dietary habits play an important role in the treatment and prevention of this condition. General classic recommendations include control of obesity, increased physical activ...

  7. PROPERTIES OF NEW STRAINS CHEMOLITHOTROPHIC BACTERIA ISOLATED FROM INDUSTRIAL SUBSTRATES

    Directory of Open Access Journals (Sweden)

    I. A.

    2015-12-01

    Full Text Available The purpose of the research was determination of strains Acidithiobacillus ferrooxidans MFLv37 and Acidithiobacillus ferrooxidans MFLad27, isolated from aboriginal consortium of coal beneficiation dumps and fly ash from coal combustion, resistance to heavy metals, forming part of these waste, as well as adaption ability of the strains to new substrates. New strains increased resistance to heavy metal ions as compared to A. ferrooxidans standard and collection strains is found; minimal inhibitory concentrations of heavy and toxic metals are determined; a number of metals that have negative impact on growth of isolated cultures are identified. It is shown that the minimal metals concentrations, at which strains growth still happens, are several times higher than their concentrations in technogenic waste. It has been established that isolated strains differed in their ability to adapt, as well as in growth rate and substrates oxidation. This is due to the specific conditions of microbiocenoses formation in making and further storage of rock dumps and fly ash, whereof the appropriate strains are isolated. The investigations indicate the necessity in directional selection of strains that are resistant to the toxic compounds and are able to oxidize various mineral substrates, as well as in their adaptation to new substrates for the extraction of heavy metals.

  8. 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...... 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...... availability of genomic information and powerful analytical techniques, mathematical models also serve as a tool for understanding the cellular metabolism and physiology....

  9. Engineering of Secondary Metabolism.

    Science.gov (United States)

    O'Connor, Sarah E

    2015-01-01

    Secondary (specialized) metabolites, produced by bacteria, fungi, plants, and other organisms, exhibit enormous structural variation, and consequently display a wide range of biological activities. Secondary metabolism improves and modulates the phenotype of the host producer. Furthermore, these biological activities have resulted in the use of secondary metabolites in a variety of industrial and pharmaceutical applications. Metabolic engineering presents a powerful strategy to improve access to these valuable molecules. A critical overview of engineering approaches in secondary metabolism is presented, both in heterologous and native hosts. The recognition of the increasing role of compartmentalization in metabolic engineering is highlighted. Engineering approaches to modify the structure of key secondary metabolite classes are also critically evaluated.

  10. 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.

  11. Fatty acid metabolism: target for metabolic syndrome

    OpenAIRE

    Wakil, Salih J.; Abu-Elheiga, Lutfi A.

    2009-01-01

    Fatty acids are a major energy source and important constituents of membrane lipids, and they serve as cellular signaling molecules that play an important role in the etiology of the metabolic syndrome. Acetyl-CoA carboxylases 1 and 2 (ACC1 and ACC2) catalyze the synthesis of malonyl-CoA, the substrate for fatty acid synthesis and the regulator of fatty acid oxidation. They are highly regulated and play important roles in the energy metabolism of fatty acids in animals, including humans. They...

  12. PPARa governs glycerol metabolism

    NARCIS (Netherlands)

    Patsouris, D.A.; Mandard, S.J.; Voshol, P.J.; Escher, P.; Tan, N.S.; Havekes, L.M.; Koenig, W.; März, W.; Müller, M.R.; Kersten, A.H.

    2004-01-01

    Glycerol, a product of adipose tissue lipolysis, is an important substrate for hepatic glucose synthesis. However, little is known about the regulation of hepatic glycerol metabolism. Here we show that several genes involved in the hepatic metabolism of glycerol, i.e., cytosolic and mitochondrial

  13. 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.

  14. Circadian Systems and Metabolism

    NARCIS (Netherlands)

    Roenneberg, Till; Merrow, Martha

    1999-01-01

    Circadian systems direct many metabolic parameters and, at the same time, they appear to be exquisitely shielded from metabolic variations. Although the recent decade of circadian research has brought insights into how circadian periodicity may be generated at the molecular level, little is known

  15. Comprehensive metabolic panel

    Science.gov (United States)

    Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20 ... Normal values for the panel tests are: Albumin : 3.4 to 5.4 g/dL (34 to 54 g/L) Alkaline phosphatase : 44 to 147 ...

  16. 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

  17. 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.

  18. Metabolic disorders in menopause.

    Science.gov (United States)

    Stachowiak, Grzegorz; Pertyński, Tomasz; Pertyńska-Marczewska, Magdalena

    2015-03-01

    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.

  19. 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.

  20. Fundamentals of cancer metabolism

    Science.gov (United States)

    DeBerardinis, Ralph J.; Chandel, Navdeep S.

    2016-01-01

    Tumors reprogram pathways of nutrient acquisition and metabolism to meet the bioenergetic, biosynthetic, and redox demands of malignant cells. These reprogrammed activities are now recognized as hallmarks of cancer, and recent work has uncovered remarkable flexibility in the specific pathways activated by tumor cells to support these key functions. In this perspective, we provide a conceptual framework to understand how and why metabolic reprogramming occurs in tumor cells, and the mechanisms linking altered metabolism to tumorigenesis and metastasis. Understanding these concepts will progressively support the development of new strategies to treat human cancer. PMID:27386546

  1. VRML metabolic network visualizer.

    Science.gov (United States)

    Rojdestvenski, Igor

    2003-03-01

    A successful date collection visualization should satisfy a set of many requirements: unification of diverse data formats, support for serendipity research, support of hierarchical structures, algorithmizability, vast information density, Internet-readiness, and other. Recently, virtual reality has made significant progress in engineering, architectural design, entertainment and communication. We experiment with the possibility of using the immersive abstract three-dimensional visualizations of the metabolic networks. We present the trial Metabolic Network Visualizer software, which produces graphical representation of a metabolic network as a VRML world from a formal description written in a simple SGML-type scripting language.

  2. 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

  3. Iron metabolism in man.

    Science.gov (United States)

    von Drygalski, Annette; Adamson, John W

    2013-09-01

    Iron metabolism in man is a highly regulated process designed to provide iron for erythropoiesis, mitochondrial energy production, electron transport, and cell proliferation. The mechanisms of iron handling also protect cells from the deleterious effects of free iron, which can produce oxidative damage of membranes, proteins, and lipids. Over the past decade, several important molecules involved in iron homeostasis have been discovered, and their function has expanded our understanding of iron trafficking under normal and pathological conditions. Physiologic iron metabolism is strongly influenced by inflammation, which clinically leads to anemia. Although hepcidin, a small circulating peptide produced by the liver, has been found to be the key regulator of iron trafficking, molecular pathways of iron sensing that control iron metabolism and hepcidin production are still incompletely understood. With this review, we provide an overview of the current understanding of iron metabolism, the recently discovered regulators of iron trafficking, and a focus on the effects of inflammation on the process.

  4. 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.

  5. Galactose metabolism and health.

    Science.gov (United States)

    Coelho, Ana I; Berry, Gerard T; Rubio-Gozalbo, M Estela

    2015-07-01

    Galactose - a key source of energy and a crucial structural element in complex molecules - is particularly important for early human development. However, galactose metabolism might be important not only for fetal and neonatal development but also for adulthood, as evidenced by the inherited disorders of galactose metabolism. The purpose of this review is to summarize the current evidence of galactose metabolism in health and disease. The biological importance of galactose goes beyond its importance as a nutrient and a metabolite. Galactose has been selected by evolutionary pressure to exert also a crucial structural role in macromolecules. Additionally, galactose has recently been reported as beneficial in a number of diseases, particularly in those affecting the brain. Galactose is crucial for human metabolism, with an established role in energy delivery and galactosylation of complex molecules, and evidence for other roles is emerging.

  6. 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)

  7. 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.

  8. Basic metabolic panel

    Science.gov (United States)

    ... Alternative Names SMAC7; Sequential multi-channel analysis with computer-7; SMA7; Metabolic panel 7; CHEM-7 References ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  9. Comprehensive Metabolic Panel

    Science.gov (United States)

    ... and Iron-binding Capacity (TIBC, UIBC) Trichomonas Testing Triglycerides Troponin Tryptase Tumor Markers Uric Acid Urinalysis Urine ... information about the current status of a person's metabolism, including the health of the kidneys and liver, ...

  10. BMP (Basic Metabolic Panel)

    Science.gov (United States)

    ... and Iron-binding Capacity (TIBC, UIBC) Trichomonas Testing Triglycerides Troponin Tryptase Tumor Markers Uric Acid Urinalysis Urine ... your healthcare provider important information about your body's metabolism , including the current status of your kidneys as ...

  11. Approach to metabolic alkalosis.

    Science.gov (United States)

    Soifer, Jennifer T; Kim, Hyung T

    2014-05-01

    Metabolic alkalosis is a common disorder, accounting for half of all acid-base disturbances in hospitalized patients. It is the result of an increase in bicarbonate production, a decrease in bicarbonate excretion, or a loss of hydrogen ions. Most causes of metabolic alkalosis can be divided into 4 categories: chloride depletion alkalosis, mineralocorticoid excess syndromes, apparent mineralocorticoid excess syndromes, and excess alkali administration. Treatment is usually supportive and based on cause of the alkalosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Evolutionary dynamics of metabolic adaptation

    NARCIS (Netherlands)

    van Hoek, M.J.A.

    2008-01-01

    In this thesis we study how organisms adapt their metabolism to a changing environment. Metabolic adaptation occurs at different timescales. Organisms adapt their metabolism via metabolic regulation, which happens in the order of minutes to hours and via evolution, which takes many generations. Here

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Glutamyl-tRNA synthetases (GluRS) provide Glu-tRNA for different processes including protein synthesis, glutamine transamidation and tetrapyrrole biosynthesis. Many organisms contain multiple GluRSs, but whether these duplications solely broaden tRNA specificity or also play additional roles...... 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...... inactivation by hemin plus hydrogen peroxide. The sensitivity to oxidation of A. ferrooxidans GluRS1 might provide a means to regulate tetrapyrrole and protein biosynthesis in response to extreme changes in both the redox and heme status of the cell via a single enzyme....

  14. 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.

  15. The Effect of Specific Conditions on Cu, Ni, Zn and Al Recovery from PCBS Waste Using Acidophilic Bacterial Strains

    Directory of Open Access Journals (Sweden)

    Mrážiková A.

    2016-03-01

    Full Text Available The objective of this work was to evaluate the influence of static, stirring and shaking conditions on copper, zinc, nickel and aluminium dissolution from printed circuit boards (PCBs using the mixed acidophilic bacterial culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results revealed that static conditions were the most effective in zinc and aluminium dissolution. Zinc was removed almost completely under static conditions, whereas maximum of nickel dissolution was reached under the stirring conditions. The highest copper recovery (36% was reached under stirring conditions. The shaking conditions appeared to be the least suitable. The relative importance of these systems for the bioleaching of copper and nickel decreased in the order: stirring, static conditions, shaking.

  16. 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.

  17. Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS{sub 2}), pyrrotite (Fe{sub 1-x}S) and molybdenite (MoS{sub 2}); Estudo da dissolucao oxidativa microbiologica de uma complexa amostra mineral contendo pirita (FeS{sub 2}), Pirrotita (Fe{sub 1-x}S) e Molibdenita (MoS{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Junior, Wilmo E.; Bevilaqua, Denise; Garcia Junior, Oswaldo [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica]. E-mail: wilmojr@bol.com.br

    2007-09-15

    This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferroxidans. 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. (author)

  18. Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS2), pyrrotite (Fe1-xS) and molybdenite (MoS2)

    International Nuclear Information System (INIS)

    Francisco Junior, Wilmo E.; Bevilaqua, Denise; Garcia Junior, Oswaldo

    2007-01-01

    This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferroxidans. 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. (author)

  19. Influence of heterotrophic microbial growth on biological oxidation of pyrite

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, E.A.; Silverstein, J. [University of Nevada, Reno, NV (United States). Dept. of Civil Engineering

    2002-12-15

    Experiments were carried out to examine the possibility that enhanced growth of heterotrophic (non-iron-oxidising) bacteria would inhibit pyrite oxidation by Acidithiobacillus ferroxidans by out-competing the more slowly growing autotrophs for oxygen, nutrients or even attachment sites on the mineral surface. Glucose was added to microcosms containing pyrite, acidic mineral solution and cultures of A-ferrooxidans and Acidiphilium acidophilus under various experimental conditions. Results suggest that encouraging the growth of heterotrophic microorganisms under acid mine drainage conditions may be a feasible strategy for decreasing both the rate and the extent of sulfide mineral oxidation. 43 refs., 8 figs., 3 tabs.

  20. Robustness of metabolic networks

    Science.gov (United States)

    Jeong, Hawoong

    2009-03-01

    We investigated the robustness of cellular metabolism by simulating the system-level computational models, and also performed the corresponding experiments to validate our predictions. We address the cellular robustness from the ``metabolite''-framework by using the novel concept of ``flux-sum,'' which is the sum of all incoming or outgoing fluxes (they are the same under the pseudo-steady state assumption). By estimating the changes of the flux-sum under various genetic and environmental perturbations, we were able to clearly decipher the metabolic robustness; the flux-sum around an essential metabolite does not change much under various perturbations. We also identified the list of the metabolites essential to cell survival, and then ``acclimator'' metabolites that can control the cell growth were discovered. Furthermore, this concept of ``metabolite essentiality'' should be useful in developing new metabolic engineering strategies for improved production of various bioproducts and designing new drugs that can fight against multi-antibiotic resistant superbacteria by knocking-down the enzyme activities around an essential metabolite. Finally, we combined a regulatory network with the metabolic network to investigate its effect on dynamic properties of cellular metabolism.

  1. Vertigo and metabolic disorders.

    Science.gov (United States)

    Santos, Maruska D' Aparecida; Bittar, Roseli Saraiva Moreira

    2012-01-01

    Metabolic disorders are accepted by many authors as being responsible for balance disorders. Because of the importance of metabolic disorders in the field of labyrinthine dysfunction, we decided to assess the prevalence of carbohydrates, lipids and thyroid hormones disorders in our patients with vestibular diseases. The study evaluates the metabolic profile of 325 patients with vertigo who sought the Otolaryngology Department of the University of São Paulo in the Hospital das Clínicas da Universidade de São Paulo. The laboratory tests ordered according to the classical research protocol were: low-density lipoprotein cholesterol fraction, TSH, T3, T4 and fasting blood sugar level. The metabolic disorders found and the ones that were observed in the general population were compared. The high level of low-density lipoprotein cholesterol, the altered levels of thyroid hormones, the higher prevalence of diabetes mellitus were the most significant changes found in the group of study. The higher amount of metabolic disorders in patients with vertigo disease reinforces the hypothesis of its influence on the etiopathogenesis of cochleovestibular symptoms.

  2. 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.

  3. New cultivation medium for "Ferrovum" and Gallionella-related strains.

    Science.gov (United States)

    Tischler, Judith S; Jwair, Rawaa Jaffer; Gelhaar, Nadja; Drechsel, Anna; Skirl, Anne-Marie; Wiacek, Claudia; Janneck, Eberhard; Schlömann, Michael

    2013-11-01

    Since the first isolation of the well-known iron oxidizer Acidithiobacillus ferrooxidans various media and techniques have been developed to isolate new species of acidophilic iron-oxidizing bacteria. A successful strategy in many cases was the use of iFeo medium in double-layer plates with a heterotrophic strain in the underlayer. However, even with samples which had been shown by molecular techniques to be dominated by "Ferrovum myxofaciens" and Gallionella-related bacteria, these bacteria were isolated considerably less frequently than Acidithiobacillus spp. on iFeo. Therefore, a new medium was designed which corresponded largely to the chemical composition of the mine water in a treatment plant dominated by the bacterial groups mentioned and was called artificial pilot-plant water (APPW). The analyses of approximately 500 colonies obtained from mine waters of two different sampling sites by PCR with primers specific for Acidithiobacillus spp., "Ferrovum" spp., Gallionella relatives, and Acidiphilium spp. revealed higher abundances of "Ferrovum" spp. and Gallionella relatives on the newly designed APPW medium than on iFeo which favored Acidithiobacillus spp. Molecular analysis of the colonies obtained indicated the occurrence of at least two species of iron-oxidizing bacteria and/or the heterotrophic Acidiphilium spp. in most of the colonies. Furthermore, the influence on the isolation of the concentrations of iron, phosphate, and ammonium of APPW, in levels of the iFeo medium previously described was studied. © 2013.

  4. Metabolism of phencyclidine

    International Nuclear Information System (INIS)

    Hoag, M.K.P.

    1987-01-01

    Phencyclidine (PCP) is a drug of abuse which may produce, in some users, a persistent schizophreniform psychosis. The possibility that long term effects of PCP are mediated by metabolic activation of the parent compound to reactive species is consistent with the demonstration of metabolism-dependent covalent binding of radiolabeled PCP in vivo and in vitro to macromolecules in rodent lung, liver, and kidney. Formation of the electrophilic iminium ion metabolite of PCP is believed to be critical for covalent binding since binding was inhibited by cyanide ion at concentrations which did not inhibit metabolism of PCP but did trap the iminium ion to form the corresponding alpha-aminonitrile. The present studies were designed to characterize further the biological fate of PCP by identifying possible macromolecular targets of the reactive metabolite(s)

  5. MYC, Metabolism, and Cancer

    Science.gov (United States)

    Stine, Zachary E.; Walton, Zandra E.; Altman, Brian J.; Hsieh, Annie L.; Dang, Chi V.

    2015-01-01

    Summary The MYC oncogene encodes a transcription factor, MYC, whose broad effects make its precise oncogenic role enigmatically elusive. The evidence to date suggests that MYC triggers selective gene expression amplification to promote cell growth and proliferation. Through its targets, MYC coordinates nutrient acquisition to produce ATP and key cellular building blocks that increase cell mass and trigger DNA replication and cell division. In cancer, genetic and epigenetic derangements silence checkpoints and unleash MYC’s cell growth- and proliferation-promoting metabolic activities. Unbridled growth in response to deregulated MYC expression creates dependence on MYC-driven metabolic pathways, such that reliance on specific metabolic enzymes provides novel targets for cancer therapy. PMID:26382145

  6. 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.

  7. Metabolic Imaging of Infection.

    Science.gov (United States)

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

    2017-11-01

    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 neoplastic tissue and then extending to more targeted probes that seek to identify specific microbial species. This focus review describes the metabolic and molecular imaging techniques currently available for clinical use in infection imaging and those that have demonstrated promising results in preclinical studies with the potential for clinical applications. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  8. Transplacental metabolic alkalosis.

    Science.gov (United States)

    Schimert, Patrik; Bernet-Buettiker, Vera; Rutishauser, Christoph; Schams, Mohammed; Frey, Bernhard

    2007-12-01

    We present a newborn with hypochloraemic metabolic alkalosis due to severe metabolic alkalosis of his mother. Hypoventilation as a leading symptom resolved quickly with treatment but may be life-threatening if not detected. In this case, the mother had a probable eating disorder. Little is known about transplacentally acquired electrolyte disorders in this setting. In the absence of symptoms, most of the cases might be undetected. The usual neonatal outcome of anorexia and/or bulimia nervosa in pregnancy is a lower birthweight and a lower risk for instrumental delivery.

  9. 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.

  10. 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...... the reader who is primarily trained in the engineering sciences with atleast a preliminary introduction to biochemistry and also shows how carbon is drained off the catabolic pathways to provide precursors for cell mass building and sometimes for important industrial products. The primary pathways...... 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...

  11. 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.

  12. DISTURBANCES OF LIPID METABOLISM

    Directory of Open Access Journals (Sweden)

    P. F. Litvitskii

    2012-01-01

    Full Text Available The article contains modern data on etiology, pathogenesis, manifestations and mechanisms of development of the most common forms of lipid metabolism disturbances in humans, such as obesity, emaciation, lipodystrophy, lipidosis, dyslipoproteinemia and atherosclerosis. The authors give the informative materials for self-testing and correction of the knowledge level.

  13. 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...

  14. Vitamin D metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Holick, M.F.; DeLuca, H.F.

    1974-01-01

    Studies on the metabolism of vitamin D in experimental animals are reviewed. It can be demonstrated that vitamin D/sub 3/ first must be hydroxylated on carbon 25 in the liver and subsequently on carbon 1 in the kidney before it can stimulate intestinal calcium absorption and bone calcium mobilization. The resultant 1,25-(OH)/sub 2/D/sub 3/ can be regarded as a hormone derived from vitamin D, whose synthesis is feedback regulated in a complex manner involving serum calcium, phosphorus, and parathyroid hormone. Evidence in experimental animals suggests that patients suffering from chronic renal disease, vitamin D-dependency disease, and hypoparathyroidism have a failure in the l-hydroxylating mechanism. The findings of vitamin D metabolism in experimental animals has led to the initiation of a search for similar systems in man. In addition, metabolites of vitamin D and their analogs are now being studied for potential use in the treatment of vitamin D-resistant bone disease. It seems likely that basic investigation into the metabolism and function of vitamin D will lead to new understanding of metabolic bone disease and to practical new methods of management in the clinics. (auth)

  15. 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.

  16. Synthetic Metabolic Pathways

    DEFF Research Database (Denmark)

    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...

  17. MYC, Metabolism, and Cancer.

    Science.gov (United States)

    Stine, Zachary E; Walton, Zandra E; Altman, Brian J; Hsieh, Annie L; Dang, Chi V

    2015-10-01

    The MYC oncogene encodes a transcription factor, MYC, whose broad effects make its precise oncogenic role enigmatically elusive. The evidence to date suggests that MYC triggers selective gene expression amplification to promote cell growth and proliferation. Through its targets, MYC coordinates nutrient acquisition to produce ATP and key cellular building blocks that increase cell mass and trigger DNA replication and cell division. In cancer, genetic and epigenetic derangements silence checkpoints and unleash MYC's cell growth- and proliferation-promoting metabolic activities. Unbridled growth in response to deregulated MYC expression creates dependence on MYC-driven metabolic pathways, such that reliance on specific metabolic enzymes provides novel targets for cancer therapy. MYC's expression and activity are tightly regulated in normal cells by multiple mechanisms, including a dependence upon growth factor stimulation and replete nutrient status. In cancer, genetic deregulation of MYC expression and loss of checkpoint components, such as TP53, permit MYC to drive malignant transformation. However, because of the reliance of MYC-driven cancers on specific metabolic pathways, synthetic lethal interactions between MYC overexpression and specific enzyme inhibitors provide novel cancer therapeutic opportunities. ©2015 American Association for Cancer Research.

  18. Neuroendocrine Regulation of Metabolism.

    Science.gov (United States)

    Cornejo, M P; Hentges, S T; Maliqueo, M; Coirini, H; Becu-Villalobos, D; Elias, C F

    2016-07-01

    Given the current environment in most developed countries, it is a challenge to maintain a good balance between calories consumed and calories burned, although maintenance of metabolic balance is key to good health. Therefore, understanding how metabolic regulation is achieved and how the dysregulation of metabolism affects health is an area of intense research. Most studies focus on the hypothalamus, which is a brain area that acts as a key regulator of metabolism. Among the nuclei that comprise the hypothalamus, the arcuate nucleus is one of the major mediators in the regulation of food intake. The regulation of energy balance is also a key factor ensuring the maintenance of any species as a result of the dependence of reproduction on energy stores. Adequate levels of energy reserves are necessary for the proper functioning of the hypothalamic-pituitary-gonadal axis. This review discusses valuable data presented in the 2015 edition of the International Workshop of Neuroendocrinology concerning the fundamental nature of the hormonal regulation of the hypothalamus and the impact on energy balance and reproduction. © 2016 British Society for Neuroendocrinology.

  19. Methanogenesis: Syntrophic metabolism

    NARCIS (Netherlands)

    Sieber, J.R.; McInerney, M.J.; Plugge, C.M.; Schink, B.; Gunsales, R.P.

    2009-01-01

    "Water is life!" All active cellular systems require water as the medium and solvent of their metabolic activities. Hydrophobic compounds and structures, which tend to exclude water, though providing inter alia excellent sources of energy and a means of biological compartmentalization, present

  20. Metabolic Reprogramming in Glioma

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Stoll

    2017-04-01

    Full Text Available 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

  1. 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

  2. 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

  3. 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

  4. Autophagy research Lessons from metabolism

    NARCIS (Netherlands)

    Meijer, Alfred J.

    2009-01-01

    Autophagy research continues to expand exponentially. Clearly autophagy and metabolism are intimately connected; however, the rapid expansion of research into this topic inevitably brings the risk that important basic knowledge of metabolism will be overlooked when considering experimental data.

  5. 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...

  6. 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...

  7. 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.

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

    African Journals Online (AJOL)

    The leaching of heavy metals increased with decrease of pH and pulp density and increase of agitation time for both bioleaching experiments. The maximum metal leaching efficiencies of 93 and 97% Zn, 86 and 96% Cu, 85 and 93% Ni, 70 and 84% Pb, 65 and 67% Cd and 30 and 34% Cr were attained with the shake flask ...

  9. [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.

  10. GALACTOSE METABOLISM I.

    Science.gov (United States)

    Fukuyama, T. T.; O'Kane, D. J.

    1962-01-01

    Fukuyama T. T. (University of Pennsylvania, Philadelphia) and D. J. O'Kane. Galactose metabolism. I. Pathway of carbon in fermentation by Streptococcus faecalis. J. Bacteriol. 84:793–796. 1962.—The pathway by which galactose-1-C14 is fermented in Streptococcus faecalis was investigated using dried-cell preparations. Lactic acid, acetic acid, formic acid, ethanol, and carbon dioxide were the end products formed, with lactic acid representing approximately 50% of the sugar fermented. The distribution of radio-activity indicated that the fermentation follows the Embden-Meyerhof route, suggesting that the difference in the formation of the products of glucose and galactose fermentation must be attributed to alternate routes of pyruvic acid metabolism. Differences in pH did not account for the dissimilar fermentation patterns. PMID:13960210

  11. 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...

  12. Spectrum of metabolic myopathies.

    Science.gov (United States)

    Angelini, Corrado

    2015-04-01

    Metabolic myopathies are disorders of utilization of carbohydrates or fat in muscles. The acute nature of energy failure is manifested either by a metabolic crisis with weakness, sometimes associated with respiratory failure, or by myoglobinuria. A typical disorder where permanent weakness occurs is glycogenosis type II (GSDII or Pompe disease) both in infantile and late-onset forms, where respiratory insufficiency is manifested by a large number of cases. In GSDII the pathogenetic mechanism is still poorly understood, and has to be attributed more to structural muscle alterations, possibly in correlation to macro-autophagy, rather than to energetic failure. This review is focused on recent advances about GSDII and its treatment, and the most recent notions about the management and treatment of other metabolic myopathies will be briefly reviewed, including glycogenosis type V (McArdle disease), glycogenosis type III (debrancher enzyme deficiency or Cori disease), CPT-II deficiency, and ETF-dehydrogenase deficiency (also known as riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency or RR-MADD). The discovery of the genetic defect in ETF dehydrogenase confirms the etiology of this syndrome. Other metabolic myopathies with massive lipid storage and weakness are carnitine deficiency, neutral lipid storage-myopathy (NLSD-M), besides RR-MADD. Enzyme replacement therapy is presented with critical consideration and for each of the lipid storage disorders, representative cases and their response to therapy is included. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis. Copyright © 2014. Published by Elsevier B.V.

  13. Autophagy, Metabolism, and Cancer.

    Science.gov (United States)

    White, Eileen; Mehnert, Janice M; Chan, Chang S

    2015-11-15

    Macroautophagy (autophagy hereafter) captures intracellular proteins and organelles and degrades them in lysosomes. The degradation breakdown products are released from lysosomes and recycled into metabolic and biosynthetic pathways. Basal autophagy provides protein and organelle quality control by eliminating damaged cellular components. Starvation-induced autophagy recycles intracellular components into metabolic pathways to sustain mitochondrial metabolic function and energy homeostasis. Recycling by autophagy is essential for yeast and mammals to survive starvation through intracellular nutrient scavenging. Autophagy suppresses degenerative diseases and has a context-dependent role in cancer. In some models, cancer initiation is suppressed by autophagy. By preventing the toxic accumulation of damaged protein and organelles, particularly mitochondria, autophagy limits oxidative stress, chronic tissue damage, and oncogenic signaling, which suppresses cancer initiation. This suggests a role for autophagy stimulation in cancer prevention, although the role of autophagy in the suppression of human cancer is unclear. In contrast, some cancers induce autophagy and are dependent on autophagy for survival. Much in the way that autophagy promotes survival in starvation, cancers can use autophagy-mediated recycling to maintain mitochondrial function and energy homeostasis to meet the elevated metabolic demand of growth and proliferation. Thus, autophagy inhibition may be beneficial for cancer therapy. Moreover, tumors are more autophagy-dependent than normal tissues, suggesting that there is a therapeutic window. Despite these insights, many important unanswered questions remain about the exact mechanisms of autophagy-mediated cancer suppression and promotion, how relevant these observations are to humans, and whether the autophagy pathway can be modulated therapeutically in cancer. See all articles in this CCR Focus section, "Cell Death and Cancer Therapy." ©2015

  14. Hypothalamic Hormones and Metabolism

    Science.gov (United States)

    Thio, Liu Lin

    2011-01-01

    Summary The ketogenic diet is an effective treatment for medically intractable epilepsy and may have antiepileptogenic, neuroprotective, and antitumor properties. While on a ketogenic diet, the body obtains most of its calories from fat rather than carbohydrates. This dramatic change in caloric composition results in a unique metabolic state. In turn, these changes in caloric composition and metabolism alter some of the neurohormones that participate in the complex neuronal network regulating energy homeostasis. Two observed changes are an increase in serum leptin and a decrease in serum insulin. These opposing changes in leptin and insulin are unique compared to other metabolic stimuli and may modify the activity of several cell signaling cascades including phosphoinositidyl-3 kinase (PI3K), adenosine monophosphate activated protein kinase (AMPK), and mammalian target of rapamycin (mTOR). These cell signaling pathways may mediate the anticonvulsant and other beneficial effects of the diet, though the neurohormonal changes induced by the ketogenic diet and the physiological consequences of these changes remain poorly characterized. PMID:21856125

  15. 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

  16. 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.

  17. 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.

  18. 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...... changes induced by complex regulatory mechanisms coordinating the activity of different metabolic pathways. It is difficult to map such global transcriptional responses by using traditional methods, because many genes in the metabolic network have relatively small changes at their transcription level. We...... in the metabolic network that follow a common transcriptional response. Thus, the algorithm enables identification of so-called reporter metabolites (metabolites around which the most significant transcriptional changes occur) and a set of connected genes with significant and coordinated response to genetic...

  19. 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.

  20. Metal metabolism and toxicity

    International Nuclear Information System (INIS)

    Bhattacharyya, M.H.; Larsen, R.P.; Whelton, B.D.; Moretti, E.S.; Peterson, D.P.; Oldham, R.D.

    1985-01-01

    This research focuses on the role of pregnancy and lactation in susceptibility to the toxic effects of cadmium and lead. Responses under investigation include lead-induced changes in pathways for vitamin D and calcium metabolism and cadmium-induced alterations in kidney function and skeletal structure. The second area focuses on the gastrointestinal absorption of plutonium and other actinide elements. Studies currently being conducted in nonhuman primates to develop a procedure to determine GI absorption values of uranium and plutonium that does not require sacrifice of the animal. 6 refs

  1. 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.

  2. 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.

  3. Cancer metabolism at a glance.

    Science.gov (United States)

    Vazquez, Alexei; Kamphorst, Jurre J; Markert, Elke K; Schug, Zachary T; Tardito, Saverio; Gottlieb, Eyal

    2016-09-15

    A defining hallmark of cancer is uncontrolled cell proliferation. This is initiated once cells have accumulated alterations in signaling pathways that control metabolism and proliferation, wherein the metabolic alterations provide the energetic and anabolic demands of enhanced cell proliferation. How these metabolic requirements are satisfied depends, in part, on the tumor microenvironment, which determines the availability of nutrients and oxygen. In this Cell Science at a Glance paper and the accompanying poster, we summarize our current understanding of cancer metabolism, emphasizing pathways of nutrient utilization and metabolism that either appear or have been proven essential for cancer cells. We also review how this knowledge has contributed to the development of anticancer therapies that target cancer metabolism. © 2016. Published by The Company of Biologists Ltd.

  4. Metabolic impact of shift work.

    Science.gov (United States)

    Zimberg, Ioná Zalcman; Fernandes Junior, Silvio A; Crispim, Cibele Aparecida; Tufik, Sergio; de Mello, Marco Tulio

    2012-01-01

    In developing countries, shift work represents a considerable contingent workforce. Recently, studies have shown that overweight and obesity are more prevalent in shift workers than day workers. In addition, shift work has been associated with a higher propensity for the development of many metabolic disorders, such as insulin resistance, diabetes, dislipidemias and metabolic syndrome. Recent data have pointed that decrease of the sleep time, desynchronization of circadian rhythm and alteration of environmental aspects are the main factors related to such problems. Shortened or disturbed sleep is among the most common health-related effects of shift work. The plausible physiological and biological mechanisms are related to the activation of the autonomic nervous system, inflammation, changes in lipid and glucose metabolism, and related changes in the risk for atherosclerosis, metabolic syndrome, and type II diabetes. The present review will discuss the impact of shift work on obesity and metabolic disorders and how disruption of sleep and circadian misalignment may contribute to these metabolic dysfunctions.

  5. Metabolic Reprogramming in Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Raquel Guimaraes Coelho

    2018-03-01

    Full Text Available Among all the adaptations of cancer cells, their ability to change metabolism from the oxidative to the glycolytic phenotype is a hallmark called the Warburg effect. Studies on tumor metabolism show that improved glycolysis and glutaminolysis are necessary to maintain rapid cell proliferation, tumor progression, and resistance to cell death. Thyroid neoplasms are common endocrine tumors that are more prevalent in women and elderly individuals. The incidence of thyroid cancer has increased in the Past decades, and recent findings describing the metabolic profiles of thyroid tumors have emerged. Currently, several drugs are in development or clinical trials that target the altered metabolic pathways of tumors are undergoing. We present a review of the metabolic reprogramming in cancerous thyroid tissues with a focus on the factors that promote enhanced glycolysis and the possible identification of promising metabolic targets in thyroid cancer.

  6. Metabolic Reprogramming in Thyroid Carcinoma

    Science.gov (United States)

    Coelho, Raquel Guimaraes; Fortunato, Rodrigo S.; Carvalho, Denise P.

    2018-01-01

    Among all the adaptations of cancer cells, their ability to change metabolism from the oxidative to the glycolytic phenotype is a hallmark called the Warburg effect. Studies on tumor metabolism show that improved glycolysis and glutaminolysis are necessary to maintain rapid cell proliferation, tumor progression, and resistance to cell death. Thyroid neoplasms are common endocrine tumors that are more prevalent in women and elderly individuals. The incidence of thyroid cancer has increased in the Past decades, and recent findings describing the metabolic profiles of thyroid tumors have emerged. Currently, several drugs are in development or clinical trials that target the altered metabolic pathways of tumors are undergoing. We present a review of the metabolic reprogramming in cancerous thyroid tissues with a focus on the factors that promote enhanced glycolysis and the possible identification of promising metabolic targets in thyroid cancer. PMID:29629339

  7. Metabolic regulation of yeast

    Science.gov (United States)

    Fiechter, A.

    1982-12-01

    Metabolic regulation which is based on endogeneous and exogeneous process variables which may act constantly or time dependently on the living cell is discussed. The observed phenomena of the regulation are the result of physical, chemical, and biological parameters. These parameters are identified. Ethanol is accumulated as an intermediate product and the synthesis of biomass is reduced. This regulatory effect of glucose is used for the aerobic production of ethanol. Very high production rates are thereby obtained. Understanding of the regulation mechanism of the glucose effect has improved. In addition to catabolite repression, several other mechanisms of enzyme regulation have been described, that are mostly governed by exogeneous factors. Glucose also affects the control of respiration in a third class of yeasts which are unable to make use of ethanol as a substrate for growth. This is due to the lack of any anaplerotic activity. As a consequence, diauxic growth behavior is reduced to a one-stage growth with a drastically reduced cell yield. The pulse chemostat technique, a systematic approach for medium design is developed and medium supplements that are essential for metabolic control are identified.

  8. 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.

  9. 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.

  10. Metabolic topography of Parkinsonism

    International Nuclear Information System (INIS)

    Kim, Jae Seung

    2007-01-01

    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

  11. Mitochondrial Metabolism in Aging Heart

    OpenAIRE

    Lesnefsky, Edward J.; Chen, Qun; Hoppel, Charles L.

    2016-01-01

    Altered mitochondrial metabolism is the underlying basis for the increased sensitivity in the aged heart to stress. The aged heart exhibits impaired metabolic flexibility, with a decreased capacity to oxidize fatty acids and enhanced dependence on glucose metabolism. Aging impairs mitochondrial oxidative phosphorylation, with a greater role played by the mitochondria located between the myofibrils, the interfibrillar mitochondria. With aging, there is a decrease in activity of complexes III a...

  12. Severe metabolic alkalosis in pregnancy

    Science.gov (United States)

    Frise, Charlotte; Noori, Muna

    2013-01-01

    Summary Metabolic alkalosis is uncommon in pregnancy and is most often the result of severe vomiting. If this is present at the time of delivery, transient metabolic derangement in the fetus can occur, potentially requiring additional organ support. A 22-year-old woman is described, who presented at 37 weeks gestation with a severe metabolic alkalosis, vomiting and acute renal and hepatic impairment. The investigations, management options and maternal and fetal outcome are described. PMID:27708709

  13. Testosterone and the metabolic syndrome

    OpenAIRE

    Muraleedharan, Vakkat; Jones, T. Hugh

    2010-01-01

    Metabolic syndrome and testosterone deficiency in men are closely Linked. Epidemiological studies have shown that Low testosterone Levels are associated with obesity, insulin resistance and an adverse Lipid profile in men. Conversely in men with metabolic syndrome and type 2 diabetes have a high prevalence of hypogonadism. Metabolic syndrome and Low testosterone status are both independently associated with increased all-cause and cardiovascular mortality. Observational and experimental data ...

  14. Bioleaching of a low grade sphalerite concentrate produced from flotation tailings

    Directory of Open Access Journals (Sweden)

    Javad Mehrabani

    2016-12-01

    Full Text Available In this research work, the zinc extraction was investigated, using bioleaching process from a low grade zinc concentrate which was produced from the accumulated flotation tailings. Zinc content was initially upgraded to 11.97% by flotation process. Bioleaching experiments were designed and carried out by a mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirilium ferrooxidans, as well as a mixed moderate thermophile bacteria in the shake flasks. Effect of two types bacteria, indigenous bacteria accompany by concentrate sample, and added mixture of bacteria were evaluated. The term of indigenous bacteria refers to the bacteria which initially exist in the natural concentrate sample. The results showed that more than 87% and 94% of Zn was dissolved in the bioleaching condition of mesophile and moderate thermophile bacteria, respectively. Comparing bioleaching and leaching tests indicated that mesophile bacteria improved Zn extraction 36%, in which contribution of concentrate indigenous bacteria (test condition of non-inoculation and added mesophile mixed bacteria were equal to 34% and 66% of that improvement, respectively. In addition, moderate thermophile bacteria improved sphalerite leaching up to 38% in which contribution of concentrate indigenous bacteria and added moderate bacteria were about 50% separately.

  15. Bacteria-assisted preparation of nano α-Fe2O3 red pigment powders from waste ferrous sulfate

    International Nuclear Information System (INIS)

    Li, Xiang; Wang, Chuankai; Zeng, Yu; Li, Panyu; Xie, Tonghui; Zhang, Yongkui

    2016-01-01

    Highlights: • A route to prepare nano α-Fe 2 O 3 red pigment from waste ferrous sulfate is proposed. • Acidithiobacillus ferrooxidans is introduced for accelerating iron oxidation. • The particle size of synthetic α-Fe 2 O 3 is ranged from 22 nm to 86 nm. • The prepared nano α-Fe 2 O 3 red pigment fulfills ISO 1248-2006. - Abstract: Massive ferrous sulfate with excess sulfuric acid is produced in titanium dioxide industry each year, ending up stockpiled or in landfills as solid waste, which is hazardous to environment and in urgent demand to be recycled. In this study, waste ferrous sulfate was used as a second raw material to synthesize nano α-Fe 2 O 3 red pigment powders with a bacteria-assisted oxidation process by Acidithiobacillus ferrooxidans. The synthesis route, mainly consisting of bio-oxidation, precipitation and calcination, was investigated by means of titration, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF) to obtain optimum conditions. Under the optimum conditions, nano α-Fe 2 O 3 red pigment powders contained 98.24 wt.% of Fe 2 O 3 were successfully prepared, with a morphology of spheroidal and particle size ranged from 22 nm to 86 nm and averaged at 45 nm. Moreover, the resulting product fulfilled ISO 1248-2006, the standards of iron oxide pigments.

  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. 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.

  18. 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...

  19. 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.

  20. Metabolic requirements for fetal growth.

    Science.gov (United States)

    Milley, J R; Simmons, M A

    1979-09-01

    Table 1 outlines a metabolic balance sheet for the sheep fetus. It is clear that maternal substrate concentrations as well as placental function are important in assuring the provision of adequate substrate to meet fetal metabolic and growth requirements. It is intriguing that the fetus appears to use substrates not usually regarded as important in extrauterine diets (lactate) and to use substrates for catabolic purposes normally thought to be primarily anabolic substrates (amino acids). This information emphasizes the hazards of extrapolating metabolic and nutritional patterns seen in extrauterine life in reaching conclusions concerning the fetus. It likewise emphasizes the importance of ongoing studies in maternal and fetal nutrition and metabolism.

  1. Regulatory Biology: Depressed Metabolic States

    Science.gov (United States)

    Holton, E. M. (Editor)

    1973-01-01

    Exobiological aspects of depressed metabolism and thermoregulation are discussed for subsequent development of biological space flight experiments. Included is a brief description of differential hypothermia in cancer chemotherapy.

  2. Atrazine Metabolism and Herbicidal Selectivity

    Science.gov (United States)

    Shimabukuro, R. H.

    1967-01-01

    Metabolism of the herbicide 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) was investigated in resistant corn (Zea mays L.) and sorghum (Sorghum vulgare Pers.), intermediately susceptible pea (Pisum sativum L.), and highly susceptible wheat (Triticum vulgare Vill.) and soybean (Glycine max Merril.). This study revealed that 2 possible pathways for atrazine metabolism exist in higher plants. All species studied were able to metabolize atrazine initially by N-dealkylation of either of the 2 substituted alkylamine groups. Corn and wheat, which contain benzoxazinone, also metabolized atrazine initially by hydrolysis in the 2-position of the s-triazine ring to form hydroxyatrazine. Subsequent metabolism by both pathways resulted in the conversion of the parent atrazine to more polar compounds and eventually into methanol-insoluble plant residue. No evidence for s-triazine ring cleavage was obtained. Both pathways for atrazine metabolism appear to detoxify atrazine. The hydroxylation pathway results in a direct conversion of a highly phytotoxic compound to a completely non-phytotoxic derivative. The dealkylation pathway leads to detoxication through one or more partially detoxified, stable intermediates. Therefore, the rate and pathways of atrazine metabolism are important in determining the tolerance of plants to the herbicide. Both quantitative and qualitative differences in atrazine metabolism were detected between resistant, intermediately susceptible, and susceptible species. The ability of plants to metabolize atrazine by N-dealkylation and the influence of this pathway in determining tolerance of plants to atrazine are discussed. Images PMID:16656648

  3. [Nutrition and metabolic syndrome].

    Science.gov (United States)

    Matía Martín, Pilar; Lecumberri Pascual, Edurne; Calle Pascual, Alfonso L

    2007-01-01

    Sufficient evidence exists in relation to the association in clinical practice between disorders in the metabolism of glucose, lipoproteins, insulin action, arterial hypertension and centrally-distributed obesity. This association is named Metabolic Syndrome. Despite the existence thereof had been questioned by the ADA and EASD, it is a useful tool affording the possibility of identifying individuals at high risk of developing cardiovascular disease. Metabolic syndrome and/or its individual components are associated with a high incidence rate of cardiovascular disease. Obesity and a sedentary lifestyle are underlying risk factors along this syndrome's pathway to disease, changes in living habits therefore being a first-line intervention in the prevention and treatment of insulin resistance, hyperglycemia, aterogenic dyslipemia and arterial hypertension. Weight loss and exercise are the keys to the overall plan, one of the most important non-pharmacological cardiovascular risk reduction strategies however still being diet. Epidemiological studies have found a high intake of simple sugars, of foods having a glycemic index and of diets with a high glycemic load to be associated to insulin resistance, type II diabetes mellitus, hypertriglyceridemia and low HDL-cholesterol figures. Los saturated fat intake in favor of polyunsaturated and monounsaturated fatty acids has been implied in a reduction of the incidence of type II diabetes mellitus and dyslipemia, although the debate is ongoing. Unrefined grain fiber in the diet has been beneficial in reducing the risk of diabetes. Among the diet patterns, the Mediterranean diet has been related to a lower incidence of diabetes and a reduction in the risk of death. Studies for intervention in the prevention of type II diabetes have suggested low-fat diets (reducing saturated and trans-fats), with a high degree of fiber and low glycemic index. Clinical trials have shown diets with small amounts of carbohydrates, low glycemic

  4. Apolipoprotein B metabolism: tracer kinetics, models, and metabolic studies.

    Science.gov (United States)

    Burnett, John R; Barrett, P Hugh R

    2002-04-01

    The study of apolipoprotein (apo) B metabolism is central to our understanding of lipoprotein metabolism. However, the assembly and secretion of apoB-containing lipoproteins is a complex process. Specialized techniques, developed and applied to in vitro and in vivo studies of apoB metabolism, have provided insights into the mechanisms involved in the regulation of this process. Moreover, these studies have important implications for understanding both the pathophysiology as well as the therapeutic options for the dyslipidemias. The purpose of this review is to examine the role of apoB in lipoprotein metabolism and to explore the applications of kinetic analysis and multicompartmental modeling to the study of apoB metabolism. New developments and significant advances over the last decade are discussed.

  5. 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.

  6. Early anaerobic metabolisms

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity......Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were...... of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent...

  7. 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.

  8. Metabolism during hypodynamia

    Science.gov (United States)

    Federov, I. V.

    1980-01-01

    Physical immobilization, inaction due to space travel, a sedentary occupation, or bed confinement due to a chronic illness elicit similar alternations in the metabolism of man and animals (rat, rabbit, dog, mouse). After a preliminary period of weight loss, there is eventually weight gain due to increased lipid storage. Protein catabolism is enhanced and anabolism depressed, with elevated urinary excretion of amino acids, creatine, and ammonia. Glycogen stores are depleted and glyconeogenesis is accelerated. Polyuria develops with subsequent redistribution of body fluids in which the blood volume of the systemic circulation is decreased and that of pulmonary circulation increased. This results in depressed production of vasopressin by the posterior pituitary which further enhances urinary water and salt loss.

  9. Genome scale metabolic modeling of cancer

    DEFF Research Database (Denmark)

    Nilsson, Avlant; Nielsen, Jens

    2017-01-01

    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 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...

  10. [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.

  11. Metabolism of endocannabinoids.

    Science.gov (United States)

    Biernacki, Michał; Skrzydlewska, Elżbieta

    2016-08-11

    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.

  12. 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.

  13. Gait Dynamics and Locomotor Metabolism

    Science.gov (United States)

    2014-12-01

    26 47. Taylor CR, Heglund NC, Maloiy GMO . Energetics and mechanics of terrestrial locomotion. I. Metabolic energy consumption as a function of...San Diego, CA: Academic Press, 1994. 110 47. Taylor CR, Heglund NC, Maloiy GMO . Energetics and mechanics of terrestrial locomotion. I. Metabolic

  14. 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.

  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 evidences...

  16. Multidimensional optimality of microbial metabolism

    NARCIS (Netherlands)

    Schuetz, Robert; Zamboni, Nicola; Zampieri, Mattia; Heinemann, Matthias; Sauer, Uwe

    2012-01-01

    Although the network topology of metabolism is well known, understanding the principles that govern the distribution of fluxes through metabolism lags behind. Experimentally, these fluxes can be measured by (13)C-flux analysis, and there has been a long-standing interest in understanding this

  17. 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%; pacute pancreatitis. Comparing survival rates, patients suffering from metabolic syndrome had a higher death rate compared to patients without metabolic syndrome (16% vs. 4.5%; pacute pancreatitis, as well as higher mortality rate. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  18. 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.

  19. 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.

  20. [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.

  1. 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

  2. Pyrrolizidine alkaloids--genotoxicity, metabolism enzymes, metabolic activation, and mechanisms.

    Science.gov (United States)

    Fu, Peter P; Xia, Qingsu; Lin, Ge; Chou, Ming W

    2004-02-01

    Pyrrolizidine alkaloid-containing plants are widely distributed in the world and are probably the most common poisonous plants affecting livestock, wildlife, and humans. Because of their abundance and potent toxicities, the mechanisms by which pyrrolizidine alkaloids induce genotoxicities, particularly carcinogenicity, were extensively studied for several decades but not exclusively elucidated until recently. To date, the pyrrolizidine alkaloid-induced genotoxicities were revealed to be elicited by the hepatic metabolism of these naturally occurring toxins. In this review, we present updated information on the metabolism, metabolizing enzymes, and the mechanisms by which pyrrolizidine alkaloids exert genotoxicity and tumorigenicity.

  3. 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.

  4. Xenobiotic Metabolism and Gut Microbiomes

    Science.gov (United States)

    Das, Anubhav; Srinivasan, Meenakshi; Ghosh, Tarini Shankar; Mande, Sharmila S.

    2016-01-01

    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. PMID:27695034

  5. 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

  6. 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.

  7. Bioleaching of uranium in batch stirred tank reactor: Process optimization using Box–Behnken design

    International Nuclear Information System (INIS)

    Eisapour, M.; Keshtkar, A.; Moosavian, M.A.; Rashidi, A.

    2013-01-01

    Highlights: ► High amount of uranium recovery achieved using Acidithiobacillus ferrooxidans. ► ANOVA shows individual variables and their squares are statistically significant. ► The model can accurately predict the behavior of uranium recovery. ► The model shows that pulp density has the greatest effect on uranium recovery. - Abstract: To design industrial reactors, it is important to identify and optimize the effective parameters of the process. Therefore, in this study, a three-level Box–Behnken factorial design was employed combining with a response surface methodology to optimize pulp density, agitation speed and aeration rate in uranium bioleaching in a stirred tank reactor using a pure native culture of Acidithiobacillus ferrooxidans. A mathematical model was then developed by applying the least squares method using the software Minitab Version 16.1.0. The second order model represents the uranium recovery as a function of pulp density, agitation speed and aeration rate. An analysis of variance was carried out to investigate the effects of individual variables and their combined interactive effects on uranium recovery. The results showed that the linear and quadratic terms of variables were statistically significant whilst the interaction terms were statistically insignificant. The model estimated that a maximum uranium extraction (99.99%) could be obtained when the pulp density, agitation speed and aeration rate were set at optimized values of 5.8% w/v, 510 rpm and 250 l/h, respectively. A confirmatory test at the optimum conditions resulted in a uranium recovery of 95%, indicating a marginal error of 4.99%. Furthermore, control tests were performed to demonstrate the effect of A. ferrooxidans in uranium bioleaching process and showed that the addition of this microorganism greatly increases the uranium recovery

  8. Equine metabolic syndrome

    Science.gov (United States)

    Morgan, R.; Keen, J.; McGowan, C.

    2015-01-01

    Laminitis is one of the most common and frustrating clinical presentations in equine practice. While the principles of treatment for laminitis have not changed for several decades, there have been some important paradigm shifts in our understanding of laminitis. Most importantly, it is essential to consider laminitis as a clinical sign of disease and not as a disease in its own right. Once this shift in thinking has occurred, it is logical to then question what disease caused the laminitis. More than 90 per cent of horses presented with laminitis as their primary clinical sign will have developed it as a consequence of endocrine disease; most commonly equine metabolic syndrome (EMS). Given the fact that many horses will have painful protracted and/or chronic recurrent disease, a good understanding of the predisposing factors and how to diagnose and manage them is crucial. Current evidence suggests that early diagnosis and effective management of EMS should be a key aim for practising veterinary surgeons to prevent the devastating consequences of laminitis. This review will focus on EMS, its diagnosis and management. PMID:26273009

  9. Nitrogen metabolism meets phytopathology.

    Science.gov (United States)

    Fagard, Mathilde; Launay, Alban; Clément, Gilles; Courtial, Julia; Dellagi, Alia; Farjad, Mahsa; Krapp, Anne; Soulié, Marie-Christine; Masclaux-Daubresse, Céline

    2014-10-01

    Nitrogen (N) is essential for life and is a major limiting factor of plant growth. Because soils frequently lack sufficient N, large quantities of inorganic N fertilizers are added to soils for crop production. However, nitrate, urea, and ammonium are a major source of global pollution, because much of the N that is not taken up by plants enters streams, groundwater, and lakes, where it affects algal production and causes an imbalance in aquatic food webs. Many agronomical data indicate that the higher use of N fertilizers during the green revolution had an impact on the incidence of crop diseases. In contrast, examples in which a decrease in N fertilization increases disease severity are also reported, indicating that there is a complex relationship linking N uptake and metabolism and the disease infection processes. Thus, although it is clear that N availability affects disease, the underlying mechanisms remain unclear. The aim of this review is to describe current knowledge of the mechanisms that link plant N status to the plant's response to pathogen infection and to the virulence and nutritional status of phytopathogens. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Revisiting the metabolic syndrome.

    Science.gov (United States)

    Chew, Gerard T; Gan, Seng Khee; Watts, Gerald F

    2006-10-16

    Metabolic syndrome (MS) refers to the clustering of cardiometabolic risk factors - including abdominal obesity, hyperglycaemia, dyslipidaemia and elevated blood pressure - that are thought to be linked to insulin resistance. MS is associated with increased risk of cardiovascular disease and type 2 diabetes. MS is common, affecting a quarter to a third of adults, and its prevalence is rising, in parallel with increasing obesity and population ageing. Operational definitions of MS have been proposed by the World Health Organization and the National Cholesterol Education Program. Recently, the International Diabetes Federation proposed a global definition that emphasised the importance of central adiposity. In cardiovascular risk assessment, MS encapsulates the contribution of non-traditional risk factors and provides a clinically useful framework for early identification of people at increased long-term risk. It should be used in conjunction with standard algorithms based on conventional risk factors, which better predict short-term risk. Management of MS should emphasise lifestyle interventions (eg, physical activity, healthy diet and weight reduction) to reduce long-term risk of cardiovascular disease and diabetes. Those at increased short-term risk should also have individual risk factors treated according to established guidelines.

  11. Acyl-Lipid Metabolism

    Science.gov (United States)

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2013-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

  12. [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.

  13. Early anaerobic metabolisms

    Science.gov (United States)

    Canfield, Don E; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8 Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent with the carbon isotope record and other considerations of the carbon cycle, that marine rates of primary production at this time were probably an order of magnitude (or more) less than today. We conclude that the flux of reduced species to the Earth surface at this time may have been sufficient to drive anaerobic ecosystems of sufficient activity to be consistent with the carbon isotope record. Conversely, an ecosystem based on oxygenic photosynthesis was also possible with complete removal of the oxygen by reaction with reduced species from the mantle. PMID:17008221

  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. Purine and pyrimidine metabolism in man V

    International Nuclear Information System (INIS)

    Nyhan, W.L.; Thompson, L.F.; Watts, R.W.E.

    1986-01-01

    This book comprises the proceedings of the Fifth International Symposium on Human Purine and Pyrimidine Metabolism. Its papers are organized under the following categories: adenosine receptors; purine receptors and the central nervous system; nucleoside and base transport; studies with antimetabolites; deoxynucleotide and nucleoside toxicity and metabolism; enzymes; purine and pyrimidine metabolism during lymphocyte differentiation; purine metabolism in skeletal muscle; purine nucleotide metabolism in the heart; purine and pyrimidine metabolism in primary cell cultures and in parasites; nucleoside kinases and drug activation; phosphoribosylpyrophosphate; S-adenosylmethionine metabolism; and the metabolic effects of interferon

  16. Cancer as a metabolic disease

    Directory of Open Access Journals (Sweden)

    Shelton Laura M

    2010-01-01

    Full Text Available Abstract Emerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which derive most of their usable energy from oxidative phosphorylation, most cancer cells become heavily dependent on substrate level phosphorylation to meet energy demands. Evidence is reviewed supporting a general hypothesis that genomic instability and essentially all hallmarks of cancer, including aerobic glycolysis (Warburg effect, can be linked to impaired mitochondrial function and energy metabolism. A view of cancer as primarily a metabolic disease will impact approaches to cancer management and prevention.

  17. Serotonergic Control of Metabolic Homeostasis

    Directory of Open Access Journals (Sweden)

    Steven C. Wyler

    2017-09-01

    Full Text Available New treatments are urgently needed to address the current epidemic of obesity and diabetes. Recent studies have highlighted multiple pathways whereby serotonin (5-HT modulates energy homeostasis, leading to a renewed interest in the identification of 5-HT-based therapies for metabolic disease. This review aims to synthesize pharmacological and genetic studies that have found diverse functions of both central and peripheral 5-HT in the control of food intake, thermogenesis, and glucose and lipid metabolism. We also discuss the potential benefits of targeting the 5-HT system to combat metabolic disease.

  18. 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 per...... for the reliable high-throughput identification of genetic targets of both known and unknown function that are directly relevant to a specific biosynthetic process....

  19. Interaction between stress responses and circadian metabolism in metabolic disease.

    Science.gov (United States)

    Yang, Zhao; Kim, Hyunbae; Ali, Arushana; Zheng, Ze; Zhang, Kezhong

    2017-09-01

    Circadian rhythms play crucial roles in orchestrating diverse physiological processes that are critical for health and disease. Dysregulated circadian rhythms are closely associated with various human metabolic diseases, including type 2 diabetes, cardiovascular disease, and non-alcoholic fatty liver disease. Modern lifestyles are frequently associated with an irregular circadian rhythm, which poses a significant risk to public health. While the central clock has a set periodicity, circadian oscillators in peripheral organs, particularly in the liver, can be entrained by metabolic alterations or stress cues. At the molecular level, the signal transduction pathways that mediate stress responses interact with, and are often integrated with, the key determinants of circadian oscillation, to maintain metabolic homeostasis under physiological or pathological conditions. In the liver, a number of nuclear receptors or transcriptional regulators, which are regulated by metabolites, hormones, the circadian clock, or environmental stressors, serve as direct links between stress responses and circadian metabolism. In this review, we summarize recent advances in the understanding of the interactions between stress responses (the endoplasmic reticulum (ER) stress response, the oxidative stress response, and the inflammatory response) and circadian metabolism, and the role of these interactions in the development of metabolic diseases.

  20. 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

  1. 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.

  2. Glycogen metabolism in humans.

    Science.gov (United States)

    Adeva-Andany, María M; González-Lucán, Manuel; Donapetry-García, Cristóbal; Fernández-Fernández, Carlos; Ameneiros-Rodríguez, Eva

    2016-06-01

    In the human body, glycogen is a branched polymer of glucose stored mainly in the liver and the skeletal muscle that supplies glucose to the blood stream during fasting periods and to the muscle cells during muscle contraction. Glycogen has been identified in other tissues such as brain, heart, kidney, adipose tissue, and erythrocytes, but glycogen function in these tissues is mostly unknown. Glycogen synthesis requires a series of reactions that include glucose entrance into the cell through transporters, phosphorylation of glucose to glucose 6-phosphate, isomerization to glucose 1-phosphate, and formation of uridine 5'-diphosphate-glucose, which is the direct glucose donor for glycogen synthesis. Glycogenin catalyzes the formation of a short glucose polymer that is extended by the action of glycogen synthase. Glycogen branching enzyme introduces branch points in the glycogen particle at even intervals. Laforin and malin are proteins involved in glycogen assembly but their specific function remains elusive in humans. Glycogen is accumulated in the liver primarily during the postprandial period and in the skeletal muscle predominantly after exercise. In the cytosol, glycogen breakdown or glycogenolysis is carried out by two enzymes, glycogen phosphorylase which releases glucose 1-phosphate from the linear chains of glycogen, and glycogen debranching enzyme which untangles the branch points. In the lysosomes, glycogen degradation is catalyzed by α-glucosidase. The glucose 6-phosphatase system catalyzes the dephosphorylation of glucose 6-phosphate to glucose, a necessary step for free glucose to leave the cell. Mutations in the genes encoding the enzymes involved in glycogen metabolism cause glycogen storage diseases.

  3. 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.

  4. Testosterone and metabolic syndrome.

    Science.gov (United States)

    Cunningham, Glenn R

    2015-01-01

    Controversies surround the usefulness of identifying patients with the metabolic syndrome (MetS). Many of the components are accepted risk factors for cardiovascular disease (CVD). Although the MetS as defined includes many men with insulin resistance, insulin resistance is not universal. The low total testosterone (TT) and sex hormone binding globulin (SHBG) levels in these men are best explained by the hyperinsulinism and increased inflammatory cytokines that accompany obesity and increased waist circumference. It is informative that low SHBG levels predict future development of the MetS. Evidence is strong relating low TT levels to CVD in men with and without the MetS; however, the relationship may not be causal. The recommendations of the International Diabetes Federation for managing the MetS include cardiovascular risk assessment, lifestyle changes in diet, exercise, weight reduction and treatment of individual components of the MetS. Unfortunately, it is uncommon to see patients with the MetS lose and maintain a 10% weight loss. Recent reports showing testosterone treatment induced dramatic changes in weight, waist circumference, insulin sensitivity, hemoglobin A1c levels and improvements in each of the components of the MetS are intriguing. While some observational studies have reported that testosterone replacement therapy increases cardiovascular events, the Food and Drug Administration in the United States has reviewed these reports and found them to be seriously flawed. Large, randomized, placebo-controlled trials are needed to provide more definitive data regarding the efficacy and safety of this treatment in middle and older men with the MetS and low TT levels.

  5. Testosterone and metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Glenn R Cunningham

    2015-04-01

    Full Text Available Controversies surround the usefulness of identifying patients with the metabolic syndrome (MetS. Many of the components are accepted risk factors for cardiovascular disease (CVD. Although the MetS as defined includes many men with insulin resistance, insulin resistance is not universal. The low total testosterone (TT and sex hormone binding globulin (SHBG levels in these men are best explained by the hyperinsulinism and increased inflammatory cytokines that accompany obesity and increased waist circumference. It is informative that low SHBG levels predict future development of the MetS. Evidence is strong relating low TT levels to CVD in men with and without the MetS; however, the relationship may not be causal. The recommendations of the International Diabetes Federation for managing the MetS include cardiovascular risk assessment, lifestyle changes in diet, exercise, weight reduction and treatment of individual components of the MetS. Unfortunately, it is uncommon to see patients with the MetS lose and maintain a 10% weight loss. Recent reports showing testosterone treatment induced dramatic changes in weight, waist circumference, insulin sensitivity, hemoglobin A1c levels and improvements in each of the components of the MetS are intriguing. While some observational studies have reported that testosterone replacement therapy increases cardiovascular events, the Food and Drug Administration in the United States has reviewed these reports and found them to be seriously flawed. Large, randomized, placebo-controlled trials are needed to provide more definitive data regarding the efficacy and safety of this treatment in middle and older men with the MetS and low TT levels.

  6. Inborn Errors of Metabolism.

    Science.gov (United States)

    Ezgu, Fatih

    2016-01-01

    Inborn errors of metabolism are single gene disorders resulting from the defects in the biochemical pathways of the body. Although these disorders are individually rare, collectively they account for a significant portion of childhood disability and deaths. Most of the disorders are inherited as autosomal recessive whereas autosomal dominant and X-linked disorders are also present. The clinical signs and symptoms arise from the accumulation of the toxic substrate, deficiency of the product, or both. Depending on the residual activity of the deficient enzyme, the initiation of the clinical picture may vary starting from the newborn period up until adulthood. Hundreds of disorders have been described until now and there has been a considerable clinical overlap between certain inborn errors. Resulting from this fact, the definite diagnosis of inborn errors depends on enzyme assays or genetic tests. Especially during the recent years, significant achievements have been gained for the biochemical and genetic diagnosis of inborn errors. Techniques such as tandem mass spectrometry and gas chromatography for biochemical diagnosis and microarrays and next-generation sequencing for the genetic diagnosis have enabled rapid and accurate diagnosis. The achievements for the diagnosis also enabled newborn screening and prenatal diagnosis. Parallel to the development the diagnostic methods; significant progress has also been obtained for the treatment. Treatment approaches such as special diets, enzyme replacement therapy, substrate inhibition, and organ transplantation have been widely used. It is obvious that by the help of the preclinical and clinical research carried out for inborn errors, better diagnostic methods and better treatment approaches will high likely be available. © 2016 Elsevier Inc. All rights reserved.

  7. 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.

  8. Metabolic engineering: past and future.

    Science.gov (United States)

    Woolston, Benjamin M; Edgar, Steven; Stephanopoulos, Gregory

    2013-01-01

    We present here a broad overview of the field of metabolic engineering, describing in the first section the key fundamental principles that define and distinguish it, as well as the technological and intellectual developments over the past approximately 20 years that have led to the current state of the art. Discussion of concepts such as metabolic flux analysis, metabolic control analysis, and rational and combinatorial methods is facilitated by illustrative examples of their application drawn from the extensive metabolic engineering literature. In the second section, we present some of the rapidly emerging technologies that we think will play pivotal roles in the continued growth of the field, from improving production metrics to expanding the range of attainable compounds.

  9. Neuroinflammatory basis of metabolic syndrome.

    Science.gov (United States)

    Purkayastha, Sudarshana; Cai, Dongsheng

    2013-10-05

    Inflammatory reaction is a fundamental defense mechanism against threat towards normal integrity and physiology. On the other hand, chronic diseases such as obesity, type 2 diabetes, hypertension and atherosclerosis, have been causally linked to chronic, low-grade inflammation in various metabolic tissues. Recent cross-disciplinary research has led to identification of hypothalamic inflammatory changes that are triggered by overnutrition, orchestrated by hypothalamic immune system, and sustained through metabolic syndrome-associated pathophysiology. While continuing research is actively trying to underpin the identity and mechanisms of these inflammatory stimuli and actions involved in metabolic syndrome disorders and related diseases, proinflammatory IκB kinase-β (IKKβ), the downstream nuclear transcription factor NF-κB and some related molecules in the hypothalamus were discovered to be pathogenically significant. This article is to summarize recent progresses in the field of neuroendocrine research addressing the central integrative role of neuroinflammation in metabolic syndrome components ranging from obesity, glucose intolerance to cardiovascular dysfunctions.

  10. 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

  11. 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.

  12. 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.

  13. Metabolic Effects of Ketogenic Diets

    OpenAIRE

    J Gordon Millichap

    1989-01-01

    The results of 24 metabolic profiles performed on 55 epileptic children receiving the classical ketogenic diet, the MCT diet, a modified MCT diet, and normal diets are reported from the University Department of Paediatrics, John Radcliffe Hospital, Oxford, England.

  14. The metabolic syndrome in HIV

    DEFF Research Database (Denmark)

    Worm, Signe W; Lundgren, Jens D

    2011-01-01

    The metabolic syndrome (MS) is a term used to describe the clustering of risk factors for cardiovascular disease (CVD), including elevated triglyceride (TG), low high density lipoprotein cholesterol (HDL), hypertension, hyperglycemia/ insulin resistance and intra-abdominal obesity. This paper...

  15. 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...

  16. Evolution of metabolic network organization

    Directory of Open Access Journals (Sweden)

    Bonchev Danail

    2010-05-01

    Full Text Available Abstract Background Comparison of metabolic networks across species is a key to understanding how evolutionary pressures shape these networks. By selecting taxa representative of different lineages or lifestyles and using a comprehensive set of descriptors of the structure and complexity of their metabolic networks, one can highlight both qualitative and quantitative differences in the metabolic organization of species subject to distinct evolutionary paths or environmental constraints. Results We used a novel representation of metabolic networks, termed network of interacting pathways or NIP, to focus on the modular, high-level organization of the metabolic capabilities of the cell. Using machine learning techniques we identified the most relevant aspects of cellular organization that change under evolutionary pressures. We considered the transitions from prokarya to eukarya (with a focus on the transitions among the archaea, bacteria and eukarya, from unicellular to multicellular eukarya, from free living to host-associated bacteria, from anaerobic to aerobic, as well as the acquisition of cell motility or growth in an environment of various levels of salinity or temperature. Intuitively, we expect organisms with more complex lifestyles to have more complex and robust metabolic networks. Here we demonstrate for the first time that such organisms are not only characterized by larger, denser networks of metabolic pathways but also have more efficiently organized cross communications, as revealed by subtle changes in network topology. These changes are unevenly distributed among metabolic pathways, with specific categories of pathways being promoted to more central locations as an answer to environmental constraints. Conclusions Combining methods from graph theory and machine learning, we have shown here that evolutionary pressures not only affects gene and protein sequences, but also specific details of the complex wiring of functional modules

  17. 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.

  18. 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 h...... 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....

  19. 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.

  20. Metabolic management of brain cancer.

    Science.gov (United States)

    Seyfried, Thomas N; Kiebish, Michael A; Marsh, Jeremy; Shelton, Laura M; Huysentruyt, Leanne C; Mukherjee, Purna

    2011-06-01

    Malignant brain tumors are a significant health problem in children and adults. Conventional therapeutic approaches have been largely unsuccessful in providing long-term management. As primarily a metabolic disease, malignant brain cancer can be managed through changes in metabolic environment. In contrast to normal neurons and glia, which readily transition to ketone bodies (β-hydroxybutyrate) for energy under reduced glucose, malignant brain tumors are strongly dependent on glycolysis for energy. The transition from glucose to ketone bodies as a major energy source is an evolutionary conserved adaptation to food deprivation that permits the survival of normal cells during extreme shifts in nutritional environment. Only those cells with a flexible genome and normal mitochondria can effectively transition from one energy state to another. Mutations restrict genomic and metabolic flexibility thus making tumor cells more vulnerable to energy stress than normal cells. We propose an alternative approach to brain cancer management that exploits the metabolic flexibility of normal cells at the expense of the genetically defective and metabolically challenged tumor cells. This approach to brain cancer management is supported from recent studies in mice and humans treated with calorie restriction and the ketogenic diet. Issues of implementation and use protocols are presented for the metabolic management of brain cancer. Copyright © 2010. Published by Elsevier B.V.

  1. 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.

  2. Drug treatment of metabolic syndrome.

    Science.gov (United States)

    Altabas, Velimir

    2013-08-01

    The metabolic syndrome is a constellation of risk factors for cardiovascular diseases including: abdominal obesity, a decreased ability to metabolize glucose (increased blood glucose levels and/or presence of insulin resistance), dyslipidemia, and hypertension. Patients who have developed this syndrome have been shown to be at an increased risk of developing cardiovascular disease and/or type 2 diabetes. Genetic factors and the environment both are important in the development of the metabolic syndrome, influencing all single components of this syndrome. The goals of therapy are to treat the underlying cause of the syndrome, to reduce morbidity, and to prevent complications, including premature death. Lifestyle modification is the preferred first-step treatment of the metabolic syndrome. There is no single effective drug treatment affecting all components of the syndrome equally known yet. However, each component of metabolic syndrome has independent goals to be achieved, so miscellaneous types of drugs are used in the treatment of this syndrome, including weight losing drugs, antidiabetics, antihypertensives, antilipemic and anticlothing drugs etc. This article provides a brief insight into contemporary drug treatment of components the metabolic syndrome.

  3. 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 • ...

  4. [Metabolic syndrome after kidney transplantation].

    Science.gov (United States)

    Nedbálková, Marta; Svojanovský, Jan; Trnavský, Karel; Kuman, Milan; Jarkovský, Jiří; Karpíšek, Michal; Souček, Miroslav

    2014-03-01

    Metabolic syndrome is a risk factor for cardiovascular diseases. Higher risk of the metabolic syndrome and its components in patients after kidney transplantation is caused by immunosuppressive therapy. THE AIM OF OUR STUDY was to evaluate the prevalence of the metabolic syndrome and its components in kidney transplant recipients and to analyse their influence on allograft function and albuminuria. In the study we monitored 69 patients after cadaveric kidney transplantation. The prevalence of the meta-bolic syndrome was 61.3 % 3 years after kidney transplantation. The prevalence of new onset diabetes mellitus after transplantation was 27 % and that of abdominal obesity 59.7 % of patients. The age of kidney transplant recipients with the metabolic syndrome was higher than of these without it, but not statistically significant. The age of kidney transplant recipients with new onset diabetes mellitus after transplantation was significantly higher, 54.0 (35.0; 69.0) years, than in patients without it, 45.5 (27.0; 60.0) years, OR (95% IS) 1.116 (1.031; 1.207), p = 0.006.The number of components of the metabolic syndrome was negatively correlated with the graft function (rs -0,275, p = 0,031). In patients with impaired renal function with estimated glomerular filtration (using MDRD equation) metabolic syndrome and hypertriglyceridaemia was significantly higher. Chronic allograft dysfunction was predicted by donor age, delayed allograft function, rejection, low level of HDL-cholesterol, hypertriglyceridaemia and hyperuricaemia. Hyperuricaemia was the only significant predictor of allograft dysfunction independently of the presence of delayed allograft function, rejection episodes and donor age. The metabolic syndrome, elevation of apolipoprotein B and nonHDL-cholesterol and increased systolic blood pressure were associated with albuminuria. Higher levels of apolipoprotein B and total cholesterol were independent predictors of increased albumin-creatinine ratio. Obesity

  5. Favourable metabolic profile sustains mitophagy and prevents metabolic abnormalities in metabolically healthy obese individuals.

    Science.gov (United States)

    Bhansali, Shipra; Bhansali, Anil; Dhawan, Veena

    2017-01-01

    Obesity-mediated oxidative stress results in mitochondrial dysfunction, which has been implicated in the pathogenesis of metabolic syndrome and T2DM. Recently, mitophagy, a cell-reparative process has emerged as a key facet in maintaining the mitochondrial health, which may contribute to contain the metabolic abnormalities in obese individuals. However, the status of mitophagy in metabolically healthy obese (MHO) and metabolically abnormal diabetic obese (MADO) subjects remains to be elucidated. Hence, the present study aims to unravel the alterations in mitochondrial oxidative stress (MOS) and mitophagy in these subjects. 60 subjects including MHNO (metabolically healthy non-obese), MHO and MADO were enrolled as per the Asian criteria for obesity (n = 20 each). Biochemical parameters, MOS indices, transcriptional and translational expression of mitophagy markers ( PINK1 , PARKIN , MFN2 , NIX , LC3 - II , and LAMP - 2 ), and transmission electron microscopic (TEM) studies were performed in peripheral blood mononuclear cells. The MHO subjects displayed a favorable metabolic profile, despite accompanied by an increased adiposity as compared to the MHNO group; while MADO group exhibited several metabolic abnormalities, inspite of similar body composition as MHO subjects. A progressive rise in the MOS was observed in MHO and MADO subjects as compared to the MHNO group, and it showed a positive and significant correlation with the body composition in these groups. Further, mitophagy remained unaltered in the MHO group, while it was significantly downregulated in the MADO group. In addition, TEM studies revealed a significant increase in the percentage of damaged mitochondria in MADO patients as compared to other groups, while MHO and MHNO groups did not show any significant alterations for the same. A favorable metabolic profile and moderate levels of MOS in the MHO group may play a crucial role in the sustenance of mitophagy, which may further limit the aggravation

  6. 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

  7. 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.

  8. Bariatric metabolic surgery.

    Science.gov (United States)

    Scopinaro, N

    2014-08-01

    According to the WHO, the worldwide prevalence of obesity body mass index (BMI) 30 kg/m² nearly doubled between 1980 and 2008, with 10% of men and 14% of women and a total of more than half a billion adults (aged >20 years old) being classed as obese. At least 2.8 million people die each year worldwide as a result of being overweight or obese, usually from the inevitable related comorbidities. It has been reported that approximately 65% of the worlds population inhabits countries where overweight and obesity are responsible for higher mortality than underweight. The recently published Interdisciplinary European Guidelines on Metabolic and Bariatric Surgery note that despite the WHO stating that excess weight is considered the fifth leading risk for deaths worldwide, it has not yet been possible to successfully curb the obesity epidemic. Moreover, severe obesity (BMI>35 kg/m²) represents a rapidly growing segment of the epidemic in which the negative effects on health and disability are especially marked. Excess weight drastically elevates a persons risk of developing a number of non-communicable diseases, such as diabetes, hypertension, stroke, dyslipidaemia, sleep apnoea, cancer, non-alcoholic steatohepatitis, and other serious comorbidities. The WHO emphasises that 44% of type 2 diabetes mellitus, 23% of ischaemic heart disease and around 741% of certain cancers are attributable to overweight and obesity. In the majority of European countries, overweight and obesity are responsible for about 80% of cases of type 2 diabetes, 35% of cases of ischaemic heart disease and 55% of cases of hypertensive disease among adults. Additionally, a range of debilitating conditions such as osteoarthritis, respiratory difficulties, gallbladder disease, infertility, and psychosocial problems, among others, which lead to reduced life expectancy, quality of life and disability, are extremely costly in terms of both absence from work and use of health resources. Noteworthy, the

  9. Metabolic reprogramming in macrophage polarization

    Directory of Open Access Journals (Sweden)

    Silvia eGalván-Peña

    2014-09-01

    Full Text Available Studying the metabolism of immune cells in recent years has emphasized the tight link existing between the metabolic state and the phenotype of these cells. Macrophages in particular are a good example of this phenomenon. Whether the macrophage obtains its energy through glycolysis or through oxidative metabolism can give rise to different phenotypes. Classically activated or M1 macrophages are key players of the first line of defense against bacterial infections and are known to obtain energy through glycolysis. Alternatively activated or M2 macrophages on the other hand, are involved in tissue repair and wound healing and use oxidative metabolism to fuel their longer-term functions. Metabolic intermediates however, are not just a source of energy but can be directly implicated in a particular macrophage phenotype. In M1 macrophages, the Krebs cycle intermediate succinate regulates HIF1α, which is responsible for driving the sustained production of the pro-inflammatory cytokine IL1β. In M2 macrophages, the sedoheptulose kinase CARKL is critical for regulating the pentose phosphate pathway. The potential to target these events and impact on disease is an exciting prospect.

  10. 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.

  11. Metabolic Profiles of Brain Metastases

    Directory of Open Access Journals (Sweden)

    Tone F. Bathen

    2013-01-01

    Full Text Available Metastasis to the brain is a feared complication of systemic cancer, associated with significant morbidity and poor prognosis. A better understanding of the tumor metabolism might help us meet the challenges in controlling brain metastases. The study aims to characterize the metabolic profile of brain metastases of different origin using high resolution magic angle spinning (HR-MAS magnetic resonance spectroscopy (MRS to correlate the metabolic profiles to clinical and pathological information. Biopsy samples of human brain metastases (n = 49 were investigated. A significant correlation between lipid signals and necrosis in brain metastases was observed (p < 0.01, irrespective of their primary origin. The principal component analysis (PCA showed that brain metastases from malignant melanomas cluster together, while lung carcinomas were metabolically heterogeneous and overlap with other subtypes. Metastatic melanomas have higher amounts of glycerophosphocholine than other brain metastases. A significant correlation between microscopically visible lipid droplets estimated by Nile Red staining and MR visible lipid signals was observed in metastatic lung carcinomas (p = 0.01, indicating that the proton MR visible lipid signals arise from cytoplasmic lipid droplets. MRS-based metabolomic profiling is a useful tool for exploring the metabolic profiles of metastatic brain tumors.

  12. Exercise training in metabolic myopathies

    DEFF Research Database (Denmark)

    Vissing, J

    2016-01-01

    , patients with FAODs typically develop symptoms later in exercise than patients with GSDs. Due to the exercise-related symptoms in metabolic myopathies, patients generally have been advised to shun physical training. However, immobility is associated with multiple health issues, and may even cause unwanted......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...

  13. Biofuel metabolic engineering with biosensors

    Science.gov (United States)

    Morgan, Stacy-Anne; Nadler, Dana C.; Yokoo, Rayka; Savage, David F.

    2016-01-01

    Metabolic engineering offers the potential to renewably produce important classes of chemicals, particularly biofuels, at an industrial scale. DNA synthesis and editing techniques can generate large pathway libraries, yet identifying the best variants is slow and cumbersome. Traditionally, analytical methods like chromatography and mass spectrometry have been used to evaluate pathway variants, but such techniques cannot be performed with high throughput. Biosensors - genetically encoded components that actuate a cellular output in response to a change in metabolite concentration - are therefore a promising tool for rapid and high-throughput evaluation of candidate pathway variants. Applying biosensors can also dynamically tune pathways in response to metabolic changes, improving balance and productivity. Here, we describe the major classes of biosensors and briefly highlight recent progress in applying them to biofuel-related metabolic pathway engineering. PMID:27768949

  14. 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...

  15. 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.

  16. 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 reacti...

  17. 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

  18. 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.

  19. 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...

  20. 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....

  1. 'Biomoleculas': cellular metabolism didactic software

    International Nuclear Information System (INIS)

    Menghi, M L; Novella, L P; Siebenlist, M R

    2007-01-01

    'Biomoleculas' is a software that deals with topics such as the digestion, cellular metabolism and excretion of nutrients. It is a pleasant, simple and didactic guide, made by and for students. In this program, each biomolecule (carbohydrates, lipids and proteins) is accompanied until its degradation and assimilation by crossing and interrelating the different metabolic channels to finally show the destination of the different metabolites formed and the way in which these are excreted. It is used at present as a teaching-learning process tool by the chair of Physiology and Biophysics at the Facultad de Ingenieria - Universidad Nacional de Entre Rios

  2. A weak link in metabolism: the metabolic capacity for glycine ...

    Indian Academy of Sciences (India)

    ... may fall significantly short of the amount needed for all metabolic uses, including collagen synthesis by about 10 g per day for a 70 kg human. This result supports earlier suggestions in the literature that glycine is a semi-essential amino acid and that it should be taken as a nutritional supplement to guarantee a healthy ...

  3. 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 ...

  4. Cancer metabolism: current perspectives and future directions

    Science.gov (United States)

    Muñoz-Pinedo, C; El Mjiyad, N; Ricci, J-E

    2012-01-01

    Cellular metabolism influences life and death decisions. An emerging theme in cancer biology is that metabolic regulation is intricately linked to cancer progression. In part, this is due to the fact that proliferation is tightly regulated by availability of nutrients. Mitogenic signals promote nutrient uptake and synthesis of DNA, RNA, proteins and lipids. Therefore, it seems straight-forward that oncogenes, that often promote proliferation, also promote metabolic changes. In this review we summarize our current understanding of how ‘metabolic transformation' is linked to oncogenic transformation, and why inhibition of metabolism may prove a cancer′s ‘Achilles' heel'. On one hand, mutation of metabolic enzymes and metabolic stress sensors confers synthetic lethality with inhibitors of metabolism. On the other hand, hyperactivation of oncogenic pathways makes tumors more susceptible to metabolic inhibition. Conversely, an adequate nutrient supply and active metabolism regulates Bcl-2 family proteins and inhibits susceptibility to apoptosis. Here, we provide an overview of the metabolic pathways that represent anti-cancer targets and the cell death pathways engaged by metabolic inhibitors. Additionally, we will detail the similarities between metabolism of cancer cells and metabolism of proliferating cells. PMID:22237205

  5. Clinical biomarkers in metabolic syndrome.

    Science.gov (United States)

    Barazzoni, Rocco; Silva, Veronica; Singer, Pierre

    2014-04-01

    A biomarker can be defined as a measurable variable that may be used as an indicator of a given biological state or condition. Biomarkers have been used in health and disease for diagnostic purposes, as tools to assess effectiveness of nutritional or drug intervention, or as risk markers to predict the development of certain diseases. In nutrition studies, selecting appropriate biomarkers is important to assess compliance, or incidence of a particular dietary component in the biochemistry of the organism, and in the diagnosis and prognosis of nutrition-related diseases. Metabolic syndrome is a cluster of cardiovascular risk factors that occur simultaneously in the same individual, and it is associated with systemic alterations that may involve several organs and tissues. Given its close association with obesity and the increasing prevalence of obesity worldwide, identifying obese individuals at risk for metabolic syndrome is a major clinical priority. Biomarkers for metabolic syndrome are therefore potential important tools to maximize the effectiveness of treatment in subjects who would likely benefit the most. Choice of biomarkers may be challenging due to the complexity of the syndrome, and this article will mainly focus on nutrition biomarkers related to the diagnosis and prognosis of the metabolic syndrome.

  6. Metabolic engineering in methanotrophic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kalyuzhnaya, MG; Puri, AW; Lidstrom, ME

    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. (C) 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  7. Synthetic biology and metabolic engineering.

    Science.gov (United States)

    Stephanopoulos, Gregory

    2012-11-16

    Metabolic engineering emerged 20 years ago as the discipline occupied with the directed modification of metabolic pathways for the microbial synthesis of various products. As such, it deals with the engineering (design, construction, and optimization) of native as well as non-natural routes of product synthesis, aided in this task by the availability of synthetic DNA, the core enabling technology of synthetic biology. The two fields, however, only partially overlap in their interest in pathway engineering. While fabrication of biobricks, synthetic cells, genetic circuits, and nonlinear cell dynamics, along with pathway engineering, have occupied researchers in the field of synthetic biology, the sum total of these areas does not constitute a coherent definition of synthetic biology with a distinct intellectual foundation and well-defined areas of application. This paper reviews the origins of the two fields and advances two distinct paradigms for each of them: that of unit operations for metabolic engineering and electronic circuits for synthetic biology. In this context, metabolic engineering is about engineering cell factories for the biological manufacturing of chemical and pharmaceutical products, whereas the main focus of synthetic biology is fundamental biological research facilitated by the use of synthetic DNA and genetic circuits.

  8. 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.

  9. Glucocorticoids, bone and energy metabolism.

    Science.gov (United States)

    Cooper, Mark S; Seibel, Markus J; Zhou, Hong

    2016-01-01

    Prolonged exposure to excessive levels of endogenous or exogenous glucocorticoids is associated with serious clinical features including altered body composition and the development of insulin resistance, impaired glucose tolerance and diabetes. It had been assumed that these adverse effects were mediated by direct effects of glucocorticoids on tissues such as adipose or liver. Recent studies have however indicated that these effects are, at least in part, mediated through the actions of glucocorticoids on bone and specifically the osteoblast. In mice, targeted abrogation of glucocorticoid signalling in osteoblasts significantly attenuated the changes in body composition and systemic fuel metabolism seen during glucocorticoid treatment. Heterotopic expression of osteocalcin in the liver of normal mice was also able to protect against the metabolic changes induced by glucocorticoids indicating that osteocalcin was the likely factor connecting bone osteoblasts to systemic fuel metabolism. Studies are now needed in humans to determine the extent to which glucocorticoid induced changes in body composition and systemic fuel metabolism are mediated through bone. This article is part of a Special Issue entitled Bone and diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. 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...

  11. Radiometric detection of bacterial metabolism

    International Nuclear Information System (INIS)

    Camargo, E.E.; Wagner Junior, H.N.

    1979-01-01

    The measurement of 14 CO 2 produced by the bacterial oxidation of labelled compounds is discussed as a means of evaluating the bacterial metabolism. The following items are discussed:automated radiometric detection, types of graphs, clinical applications of the radiometric system and influential factors. Complementary studies on bacterial assimilation of substances are presented. (M.A.) [pt

  12. Substrate channeling in proline metabolism

    Science.gov (United States)

    Arentson, Benjamin W.; Sanyal, Nikhilesh; Becker, Donald F.

    2012-01-01

    Proline metabolism is an important pathway that has relevance in several cellular functions such as redox balance, apoptosis, and cell survival. Results from different groups have indicated that substrate channeling of proline metabolic intermediates may be a critical mechanism. One intermediate is pyrroline-5-carboxylate (P5C), which upon hydrolysis opens to glutamic semialdehyde (GSA). Recent structural and kinetic evidence indicate substrate channeling of P5C/GSA occurs in the proline catabolic pathway between the proline dehydrogenase and P5C dehydrogenase active sites of bifunctional proline utilization A (PutA). Substrate channeling in PutA is proposed to facilitate the hydrolysis of P5C to GSA which is unfavorable at physiological pH. The second intermediate, gamma-glutamyl phosphate, is part of the proline biosynthetic pathway and is extremely labile. Substrate channeling of gamma-glutamyl phosphate is thought to be necessary to protect it from bulk solvent. Because of the unfavorable equilibrium of P5C/GSA and the reactivity of gamma-glutamyl phosphate, substrate channeling likely improves the efficiency of proline metabolism. Here, we outline general strategies for testing substrate channeling and review the evidence for channeling in proline metabolism. PMID:22201749

  13. Automated metabolic reconstruction for Methanococcus jannaschii

    Science.gov (United States)

    Tsoka, Sophia; Simon, David; Ouzounis, Christos A.

    2004-01-01

    We present the computational prediction and synthesis of the metabolic pathways in Methanococcus jannaschii from its genomic sequence using the PathoLogic software. Metabolic reconstruction is based on a reference knowledge base of metabolic pathways and is performed with minimal manual intervention. We predict the existence of 609 metabolic reactions that are assembled in 113 metabolic pathways and an additional 17 super-pathways consisting of one or more component pathways. These assignments represent significantly improved enzyme and pathway predictions compared with previous metabolic reconstructions, and some key metabolic reactions, previously missing, have been identified. Our results, in the form of enzymatic assignments and metabolic pathway predictions, form a database (MJCyc) that is accessible over the World Wide Web for further dissemination among members of the scientific community. PMID:15810431

  14. Automated metabolic reconstruction for Methanococcus jannaschii

    Directory of Open Access Journals (Sweden)

    Sophia Tsoka

    2004-01-01

    Full Text Available We present the computational prediction and synthesis of the metabolic pathways in Methanococcus jannaschii from its genomic sequence using the PathoLogic software. Metabolic reconstruction is based on a reference knowledge base of metabolic pathways and is performed with minimal manual intervention. We predict the existence of 609 metabolic reactions that are assembled in 113 metabolic pathways and an additional 17 super-pathways consisting of one or more component pathways. These assignments represent significantly improved enzyme and pathway predictions compared with previous metabolic reconstructions, and some key metabolic reactions, previously missing, have been identified. Our results, in the form of enzymatic assignments and metabolic pathway predictions, form a database (MJCyc that is accessible over the World Wide Web for further dissemination among members of the scientific community.

  15. Nonessential amino acid metabolism in breast cancer.

    Science.gov (United States)

    Geck, Renee C; Toker, Alex

    2016-09-01

    Interest in studying cancer metabolism has risen in recent years, as it has become evident that the relationship between cancer and metabolic pathways could reveal novel biomarkers and therapeutic targets. Metabolic starvation therapy is particularly promising due to its low toxicity. Nonessential amino acids are promising metabolites for such therapy because they become essential in many tumor cells, including breast cancer cells. This review will focus on four nonessential amino acid metabolism pathways: glutamine-glutamate, serine-glycine, cysteine, and arginine-proline metabolism. Recent studies of these amino acids have revealed metabolic enzymes that have the potential to be effective as cancer therapy targets or biomarkers for response to metabolic starvation therapy. The review will also discuss features of nonessential amino acid metabolism that merit further investigation to determine their relevancy to breast cancer treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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 ...

  17. Albumin metabolism in health and disease

    International Nuclear Information System (INIS)

    Kirsch, R.E.; Saunders, S.J.; Brock, J.F.

    1979-01-01

    Studies performed at the University of Cape Town on the metabolism of albumin have been reviewed. The control of albumin metabolism in protein energy malnutrition, in acute exposure to alcohol and after partial hepatectomy in the rat is discussed

  18. 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.

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

    African Journals Online (AJOL)

    Glycaemic Control, Dyslipidaemia and Metabolic Syndrome among Recently Diagnosed Diabetes Mellitus Patients in Tamale Teaching Hospital, Ghana. ... West African Journal of Medicine ... BACKGROUND: Poor glycaemic control, dyslipidaemia and metabolic syndrome are all risk factors for cardiovascular disease.

  20. Targeting metabolic disorders by natural products

    OpenAIRE

    Tabatabaei-Malazy, Ozra; Larijani, Bagher; Abdollahi, Mohammad

    2015-01-01

    The most prevalent metabolic disorders are diabetes mellitus, obesity, dyslipidemia, osteoporosis and metabolic syndrome, which are developed when normal metabolic processes are disturbed. The most common pathophysiologies of the above disorders are oxidative stress, Nrf2 pathways, epigenetic, and change in miRNA expression. There is a challenge in the prevention and treatment of metabolic disorders due to severe adverse effects of some synthetic drugs, their high cost, lack of safety and pov...

  1. 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...

  2. 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

  3. Metabolic disorders of purine metabolism affecting the nervous system.

    Science.gov (United States)

    Jinnah, H A; Sabina, Richard L; Van Den Berghe, Georges

    2013-01-01

    The purines are a group of molecules used by all cells for many vital biochemical processes including energy-requiring enzymatic reactions, cofactor-requiring reactions, synthesis of DNA or RNA, signaling pathways within and between cells, and other processes. Defects in some of the enzymes of purine metabolism are known to be associated with specific clinical disorders, and neurological problems may be a presenting sign or the predominant clinical problem for several of them. This chapter describes three disorders for which the clinical features and metabolic basis are well characterized. Deficiency of adenylosuccinate-lyase (ADSL) causes psychomotor retardation, epilepsy, and autistic features. Lesch-Nyhan disease is caused by deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) and is characterized by hyperuricemia, motor and cognitive disability, and self-injurious behavior. Deficiency of myoadenylate deaminase (mAMPD) is associated with myopathic features. In addition to these disorders, several other disorders are briefly summarized. These include defects of phosphoribosylpyrophosphate synthase, adenosine deaminase (ADA), purine nucleoside phosphorylase (PND), deoxyguanosine kinase (dGK), or IMP dehydrogenase (IMPDH). Each of these disorders provides an unusual window on the unique importance of purine metabolism for function of different parts of the nervous system. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Metabolic markers in sports medicine.

    Science.gov (United States)

    Banfi, Giuseppe; Colombini, Alessandra; Lombardi, Giovanni; Lubkowska, Anna

    2012-01-01

    Physical exercise induces adaptations in metabolism considered beneficial for health. Athletic performance is linked to adaptations, training, and correct nutrition in individuals with genetic traits that can facilitate such adaptations. Intense and continuous exercise, training, and competitions, however, can induce changes in the serum concentrations of numerous laboratory parameters. When these modifications, especially elevated laboratory levels, result outside the reference range, further examinations are ordered or participation in training and competition is discontinued or sports practice loses its appeal. In order to correctly interpret commonly used laboratory data, laboratory professionals and sport physicians need to know the behavior of laboratory parameters during and after practice and competition. We reviewed the literature on liver, kidney, muscle, heart, energy, and bone parameters in athletes with a view to increase the knowledge about clinical chemistry applied to sport and to stimulate studies in this field. In liver metabolism, the interpretation of serum aminotransferases concentration in athletes should consider the release of aspartate aminotransferase (AST) from muscle and of alanine aminotransferase (ALT) mainly from the liver, when bilirubin can be elevated because of continuous hemolysis, which is typical of exercise. Muscle metabolism parameters such as creatine kinase (CK) are typically increased after exercise. This parameter can be used to interpret the physiological release of CK from muscle, its altered release due to rhabdomyolysis, or incomplete recovery due to overreaching or trauma. Cardiac markers are released during exercise, and especially endurance training. Increases in these markers should not simply be interpreted as a signal of cardiac damage or wall stress but rather as a sign of regulation of myocardial adaptation. Renal function can be followed in athletes by measuring serum creatinine concentration, but it should

  5. 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

  6. Urban metabolism: A review of research methodologies

    International Nuclear Information System (INIS)

    Zhang, Yan

    2013-01-01

    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. Highlights: •Urban metabolic processes can be analyzed by regarding cities as superorganisms. •Urban metabolism methods include accounting, assessment, modeling, and regulation. •Research methodologies have improved greatly since this field began in 1965. •Future research should focus on carbon metabolism and optimal regulation. -- The author reviews research progress in the field of urban metabolism, and based on her literature review, proposes directions for future research

  7. Metabolism of fluoroacetate by lettuce

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.F.V.

    1973-10-01

    The metabolism of fluoroacetate was studied at sub-toxic levels. In order to isolate sufficient metabolites for structural studies, a plant system was chosen, since plants are able to withstand much higher levels of fluoroacetate than most animals. Lettuce was used because of its convenient size and ready availability throughout the year. The reaction between fluroacetate and glutathione is discussed; it strongly resembles the metabolism of many aliphatic and aromatic halogen compounds by mammalian liver. It is possible that this detoxifying reaction occurs in the liver of fluoroacetate-poisoned animals since the level of citrate found in this organ is always less than in the other organs tested. 20 references, 9 figures, 2 tables.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. [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.

  14. 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.

  15. The cradle of metabolic disease

    OpenAIRE

    Galjaard, Sander

    2015-01-01

    Summary -Vascular development and FETAL body composition during pregnancy- The effects of maternal adiposity (high body mass index - high BMI -), nutrient intake and storage (gestational weight gain - GWG -) and (abnormal) glucose tolerance (gestational diabetes - GDM - ) are regarded important cornerstones in metabolic research in pregnancy. In Chapter 1, I explained, that they play an important role in the development of complications in the mother and the fetus, both short- and long-ter...

  16. The energy metabolism of megacities

    International Nuclear Information System (INIS)

    Facchini, Angelo; Kennedy, Chris; Stewart, Iain; Mele, Renata

    2017-01-01

    Highlights: • Energy metabolism leads to a better management of energy use in megacities. • Insights on strategies to improve energy efficiency and reduce resource consumption. • We find a regionalization of energy flows and sectoral energy use. • Scaling law for energy Vs density suggests strategies for compact cities planning. • Supports development of models to reduce GHG emissions and increase resilience. - Abstract: Due to their sheer size and complexity, megacities are extreme examples in which both negative and positive aspects of urbanization co-exist and are amplified. Especially in emerging countries they are becoming the dominant paradigm of the future urbanization, representing a sustainability challenge both from the point of view of energy and resource consumption, and from the point of view of climate change adaptation and mitigation. In this paper we compare the energy metabolism in 27 of the world’s megacities including details of mobile and stationary energy consumption patterns, fuels used, as well as end-use patterns and electricity generation mix. Our results show that per capita total energy consumption scales with urban population density according to a power law characterized by the universal −3/4 scaling, pointing out that compact cities are more energy efficient with respect to dispersed cities. By comparing energy sources and sectoral end use, also focusing on electricity use and generation source, we found a significant regionalization of energy metabolism, and we discuss the implication for resilience, infrastructure planning, GHG emissions, and policies for infrastructure decarbonization. The comparison of the energy metabolism can lead to a more appropriate management of energy use patterns and electricity generation mix in megacities, giving insights on strategies to improve urban energy efficiency and reducing environmental pressure of megacities.

  17. Renal Ammonia Metabolism and Transport

    Science.gov (United States)

    Weiner, I. David; Verlander, Jill W.

    2015-01-01

    Renal ammonia metabolism and transport mediates a central role in acid-base homeostasis. In contrast to most renal solutes, the majority of renal ammonia excretion derives from intrarenal production, not from glomerular filtration. Renal ammoniagenesis predominantly results from glutamine metabolism, which produces 2 NH4+ and 2 HCO3− for each glutamine metabolized. The proximal tubule is the primary site for ammoniagenesis, but there is evidence for ammoniagenesis by most renal epithelial cells. Ammonia produced in the kidney is either excreted into the urine or returned to the systemic circulation through the renal veins. Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3−-consuming process, resulting in no net benefit to acid-base homeostasis. Highly regulated ammonia transport by renal epithelial cells determines the proportion of ammonia excreted in the urine versus returned to the systemic circulation. The traditional paradigm of ammonia transport involving passive NH3 diffusion, protonation in the lumen and NH4+ trapping due to an inability to cross plasma membranes is being replaced by the recognition of limited plasma membrane NH3 permeability in combination with the presence of specific NH3-transporting and NH4+-transporting proteins in specific renal epithelial cells. Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K+, and by several hormones, such as mineralocorticoids, glucocorticoids and angiotensin II. This coordinated process of regulated ammonia production and transport is critical for the effective maintenance of acid-base homeostasis. PMID:23720285

  18. Metabolic Causes of Epileptic Encephalopathy

    OpenAIRE

    Yu, Joe Yuezhou; Pearl, Phillip L.

    2013-01-01

    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 u...

  19. Mitochondrial Metabolism in Aging Heart.

    Science.gov (United States)

    Lesnefsky, Edward J; Chen, Qun; Hoppel, Charles L

    2016-05-13

    Altered mitochondrial metabolism is the underlying basis for the increased sensitivity in the aged heart to stress. The aged heart exhibits impaired metabolic flexibility, with a decreased capacity to oxidize fatty acids and enhanced dependence on glucose metabolism. Aging impairs mitochondrial oxidative phosphorylation, with a greater role played by the mitochondria located between the myofibrils, the interfibrillar mitochondria. With aging, there is a decrease in activity of complexes III and IV, which account for the decrease in respiration. Furthermore, aging decreases mitochondrial content among the myofibrils. The end result is that in the interfibrillar area, there is ≈50% decrease in mitochondrial function, affecting all substrates. The defective mitochondria persist in the aged heart, leading to enhanced oxidant production and oxidative injury and the activation of oxidant signaling for cell death. Aging defects in mitochondria represent new therapeutic targets, whether by manipulation of the mitochondrial proteome, modulation of electron transport, activation of biogenesis or mitophagy, or the regulation of mitochondrial fission and fusion. These mechanisms provide new ways to attenuate cardiac disease in elders by preemptive treatment of age-related defects, in contrast to the treatment of disease-induced dysfunction. © 2016 American Heart Association, Inc.

  20. 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

  1. Mitochondrial Metabolism in Aging Heart

    Science.gov (United States)

    Lesnefsky, Edward J.; Chen, Qun; Hoppel, Charles L.

    2016-01-01

    Altered mitochondrial metabolism is the underlying basis for the increased sensitivity in the aged heart to stress. The aged heart exhibits impaired metabolic flexibility, with a decreased capacity to oxidize fatty acids and enhanced dependence on glucose metabolism. Aging impairs mitochondrial oxidative phosphorylation, with a greater role played by the mitochondria located between the myofibrils, the interfibrillar mitochondria. With aging, there is a decrease in activity of complexes III and IV, which account for the decrease in respiration. Furthermore, aging decreases mitochondrial content among the myofibrils. The end result is that in the interfibrillar area there is an approximate 50% decrease in mitochondrial function, affecting all substrates. The defective mitochondria persist in the aged heart, leading to enhanced oxidant production and oxidative injury and the activation of oxidant signaling for cell death. Aging defects in mitochondria represent new therapeutic targets, whether by manipulation of the mitochondrial proteome, modulation of electron transport, activation of biogenesis or mitophagy, or the regulation of mitochondrial fission and fusion. These mechanisms provide new ways to attenuate cardiac disease in elders by preemptive treatment of age-related defects, in contrast to the treatment of disease-induced dysfunction. PMID:27174952

  2. Genetic determinants of HDL metabolism.

    Science.gov (United States)

    Ossoli, A; Gomaraschi, M; Franceschini, G; Calabresi, L

    2014-01-01

    Plasma high density lipoproteins (HDL) comprise a highly heterogeneous family of lipoprotein particles, with subclasses that can be separated and identified according to density, size, surface charge as well as shape and protein composition. There is evidence that these subclasses may differ in their functional properties. The individual plasma HDL cholesterol (HDL-C) level is generally taken as a snapshot of the steady-state concentration of all circulating HDL subclasses together, but this is insufficient to capture the structural and functional variation in HDL particles. HDL are continuously remodeled and metabolized in plasma and interstitial fluids, through the interaction with a large number of factors, including structural proteins, membrane transporters, enzymes, transfer proteins and receptors. Genetic variation in these factors can lead to essential changes in plasma HDL levels, and to remarkable changes in HDL particle density, size, surface charge, shape, and composition in lipids and apolipoproteins. This review discusses the impact of rare mutations and common variants in genes encoding factors involved in HDL remodeling and metabolism on plasma HDL-C levels and particle distribution. The study of the effects of human genetic variation in major players in HDL metabolism provides important clues on how individual factors modulate the formation, maturation, remodeling and catabolism of HDL.

  3. DNA Damage, Repair, and Cancer Metabolism

    Science.gov (United States)

    Turgeon, Marc-Olivier; Perry, Nicholas J. S.; Poulogiannis, George

    2018-01-01

    Although there has been a renewed interest in the field of cancer metabolism in the last decade, the link between metabolism and DNA damage/DNA repair in cancer has yet to be appreciably explored. In this review, we examine the evidence connecting DNA damage and repair mechanisms with cell metabolism through three principal links. (1) Regulation of methyl- and acetyl-group donors through different metabolic pathways can impact DNA folding and remodeling, an essential part of accurate double strand break repair. (2) Glutamine, aspartate, and other nutrients are essential for de novo nucleotide synthesis, which dictates the availability of the nucleotide pool, and thereby influences DNA repair and replication. (3) Reactive oxygen species, which can increase oxidative DNA damage and hence the load of the DNA-repair machinery, are regulated through different metabolic pathways. Interestingly, while metabolism affects DNA repair, DNA damage can also induce metabolic rewiring. Activation of the DNA damage response (DDR) triggers an increase in nucleotide synthesis and anabolic glucose metabolism, while also reducing glutamine anaplerosis. Furthermore, mutations in genes involved in the DDR and DNA repair also lead to metabolic rewiring. Links between cancer metabolism and DNA damage/DNA repair are increasingly apparent, yielding opportunities to investigate the mechanistic basis behind potential metabolic vulnerabilities of a substantial fraction of tumors. PMID:29459886

  4. Metabolism and the Circadian Clock Converge

    Science.gov (United States)

    Eckel-Mahan, Kristin

    2013-01-01

    Circadian rhythms occur in almost all species and control vital aspects of our physiology, from sleeping and waking to neurotransmitter secretion and cellular metabolism. Epidemiological studies from recent decades have supported a unique role for circadian rhythm in metabolism. As evidenced by individuals working night or rotating shifts, but also by rodent models of circadian arrhythmia, disruption of the circadian cycle is strongly associated with metabolic imbalance. Some genetically engineered mouse models of circadian rhythmicity are obese and show hallmark signs of the metabolic syndrome. Whether these phenotypes are due to the loss of distinct circadian clock genes within a specific tissue versus the disruption of rhythmic physiological activities (such as eating and sleeping) remains a cynosure within the fields of chronobiology and metabolism. Becoming more apparent is that from metabolites to transcription factors, the circadian clock interfaces with metabolism in numerous ways that are essential for maintaining metabolic homeostasis. PMID:23303907

  5. 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

  6. Metabolic syndrome--neurotrophic hypothesis.

    Science.gov (United States)

    Hristova, M; Aloe, L

    2006-01-01

    An increasing number of researchers of the metabolic syndrome assume that many mechanisms are involved in its complex pathophysiology such as an increased sympathetic activity, disorders of the hypothalamo-pituitary-adrenal axis, the action of chronic subclinical infections, proinflammatory cytokines, and the effect of adipocytokines or psychoemotional stress. An increasing body of scientific research in this field confirms the role of the neurotrophins and mastocytes in the pathogenesis of inflammatory and immune diseases. Recently it has been proved that neurotrophins and mastocytes have metabotrophic effects and take part in the carbohydrate and lipid metabolism. In the early stage of the metabolic syndrome we established a statistically significant increase in the plasma levels of the nerve growth factor. In the generalized stage the plasma levels of the neutrophines were statistically decreased in comparison to those in the healthy controls. We consider that the neurotrophin deficit is likely to play a significant pathogenic role in the development of the metabolic anthropometric and vascular manifestations of the generalized stage of MetSyn. We suggest a hypothesis for the etiopathogenesis of the metabolic syndrome based on the neuro-immuno-endocrine interactions. The specific pathogenic pathways of MetSyn development include: (1) increased tissue and plasma levels of proinflammatory cytokines Interleukin-1(IL-1), Interleukin-6 (IL-6 ) and tumor necrosis factor - alpha (TNF-alpha) caused by inflammatory and/or emotional distress; (2) increased plasma levels of neurotrophin - nerve growth factor (NGF) caused by the high IL-1, IL-6 and TNFalpha levels; (3) high plasma levels of NGF which enhance activation of: the autonomous nerve system--vegetodystonia (disbalance of neurotransmitters); Neuropeptide Y (NPY)--enhanced feeding, obesity and increased leptin plasma levels; hypothalamo-pituitary-adrenal axis--increased corticotropin-releasing hormone (CRH) and

  7. 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

  8. Metabolic signatures of bacterial vaginosis.

    Science.gov (United States)

    Srinivasan, Sujatha; Morgan, Martin T; Fiedler, Tina L; Djukovic, Danijel; Hoffman, Noah G; Raftery, Daniel; Marrazzo, Jeanne M; Fredricks, David N

    2015-04-14

    Bacterial vaginosis (BV) is characterized by shifts in the vaginal microbiota from Lactobacillus dominant to a microbiota with diverse anaerobic bacteria. Few studies have linked specific metabolites with bacteria found in the human vagina. Here, we report dramatic differences in metabolite compositions and concentrations associated with BV using a global metabolomics approach. We further validated important metabolites using samples from a second cohort of women and a different platform to measure metabolites. In the primary study, we compared metabolite profiles in cervicovaginal lavage fluid from 40 women with BV and 20 women without BV. Vaginal bacterial representation was determined using broad-range PCR with pyrosequencing and concentrations of bacteria by quantitative PCR. We detected 279 named biochemicals; levels of 62% of metabolites were significantly different in women with BV. Unsupervised clustering of metabolites separated women with and without BV. Women with BV have metabolite profiles marked by lower concentrations of amino acids and dipeptides, concomitant with higher levels of amino acid catabolites and polyamines. Higher levels of the signaling eicosanoid 12-hydroxyeicosatetraenoic acid (12-HETE), a biomarker for inflammation, were noted in BV. Lactobacillus crispatus and Lactobacillus jensenii exhibited similar metabolite correlation patterns, which were distinct from correlation patterns exhibited by BV-associated bacteria. Several metabolites were significantly associated with clinical signs and symptoms (Amsel criteria) used to diagnose BV, and no metabolite was associated with all four clinical criteria. BV has strong metabolic signatures across multiple metabolic pathways, and these signatures are associated with the presence and concentrations of particular bacteria. Bacterial vaginosis (BV) is a common but highly enigmatic condition that is associated with adverse outcomes for women and their neonates. Small molecule metabolites in the

  9. Novel metabolic pathways for linoleic and arachidonic acid metabolism.

    Science.gov (United States)

    Moghaddam, M; Motoba, K; Borhan, B; Pinot, F; Hammock, B D

    1996-08-13

    Mouse liver microsomes oxidized linoleic acid to form 9,10- or 12,13-epoxyoctadecenoate. These monoepoxides were subsequently hydrolyzed to their corresponding diols in the absence of the microsomal epoxide hydrolase inhibitor, 1,2-epoxy-3,3,3-trichloropropane. Furthermore, both 9,10- and 12,13-epoxyoctadecenoates were oxidized to diepoxyoctadecanoate at apparently identical rates by mouse liver microsomal P-450 epoxidation. Both epoxyoctadecanoates and diepoxyoctadecanoates were converted to tetrahydrofuran-diols by microsomes. Tetrahydroxides of linoleate were produced as minor metabolites. Arachidonic acid was metabolized to epoxyeicosatrienoates, dihydroxyeicosatrienoates, and monohydroxyeicosatetraenoates by the microsomes. Microsomes prepared from clofibrate (but not phenobarbital) -treated mice exhibited much higher production rates for epoxyeicosatrienoates and vic-dihydroxyeicosatrienoates. This indicated an induction of P-450 epoxygenase(s) and microsomal epoxide hydrolase in mice by clofibrate and not by phenobarbital. Incubation of synthetic epoxyeicosatrienoates with microsomes led to the production of diepoxyeicosadienoates. Among chemically generated diepoxyeicosadienoate isomers, three of them possessing adjacent diepoxides were hydrolyzed to their diol epoxides which cyclized to the corresponding tetrahydrofuran-diols by microsomes as well as soluble epoxide hydrolase at a much higher rate. Larger cyclic products from non-adjacent diepoxides were not observed. The results of our in vitro experiments suggest that linoleic and arachidonic acid can be metabolized to their tetrahydrofuran-diols by two consecutive microsomal cytochrome P-450 epoxidations followed by microsomal or soluble epoxide hydrolase catalyzed hydrolysis of the epoxides. Incubation experiments with the S-9 fractions indicate that the soluble epoxide hydrolase is more important in this conversion. This manuscript is the first report of techniques for the separation and

  10. [Acid-base homeostasis: metabolic acidosis and metabolic alkalosis].

    Science.gov (United States)

    Dussol, Bertrand

    2014-07-01

    Acid-base homeostasis ensured by the kidneys, which maintain the equilibrium between proton generation by cellular metabolism and proton excretion in urine. This requirement is lifesaving because of the protons' ability to bind to anionic proteins in the extracellular space, modifying their structure and functions. The kidneys also regenerate bicarbonates. The kidney is not the sole organ in charge of maintaining blood pH in a very narrow range; lungs are also involved since they allow a large amount of volatile acid generated by cellular respiration to be eliminated. Copyright © 2014 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  11. 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.

  12. 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.

  13. 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.

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

    Science.gov (United States)

    Jia, Gengjie; Stephanopoulos, Gregory; Gunawan, Rudiyanto

    2012-01-01

    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. PMID:24957767

  15. Phototransduction Influences Metabolic Flux and Nucleotide Metabolism in Mouse Retina.

    Science.gov (United States)

    Du, Jianhai; Rountree, Austin; Cleghorn, Whitney M; Contreras, Laura; Lindsay, Ken J; Sadilek, Martin; Gu, Haiwei; Djukovic, Danijel; Raftery, Dan; Satrústegui, Jorgina; Kanow, Mark; Chan, Lawrence; Tsang, Stephen H; Sweet, Ian R; Hurley, James B

    2016-02-26

    Production of energy in a cell must keep pace with demand. Photoreceptors use ATP to maintain ion gradients in darkness, whereas in light they use it to support phototransduction. Matching production with consumption can be accomplished by coupling production directly to consumption. Alternatively, production can be set by a signal that anticipates demand. In this report we investigate the hypothesis that signaling through phototransduction controls production of energy in mouse retinas. We found that respiration in mouse retinas is not coupled tightly to ATP consumption. By analyzing metabolic flux in mouse retinas, we also found that phototransduction slows metabolic flux through glycolysis and through intermediates of the citric acid cycle. We also evaluated the relative contributions of regulation of the activities of α-ketoglutarate dehydrogenase and the aspartate-glutamate carrier 1. In addition, a comprehensive analysis of the retinal metabolome showed that phototransduction also influences steady-state concentrations of 5'-GMP, ribose-5-phosphate, ketone bodies, and purines. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. 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.

  17. Interaction between vitamin B6 metabolism, nitrogen metabolism and autoimmunity.

    Science.gov (United States)

    Colinas, Maite; Fitzpatrick, Teresa B

    2016-01-01

    The essential micronutrient vitamin B6 is best known in its enzymatic cofactor form, pyridoxal 5'-phosphate (PLP). However, vitamin B6 comprises the amine pyridoxamine 5'-phosphate (PMP) and the alcohol pyridoxine 5'-phosphate (PNP) in addition to PLP, as well as their corresponding non-phosphorylated forms. The different B6 forms (called vitamers) are enzymatically interconverted in a ubiquitous salvage pathway. Recently, we have shown that balancing the ratio of the different B6 vitamers in particular PMP by the PMP/PNP oxidase PDX3 is essential for growth and development in Arabidopsis thaliana. Intriguingly, nitrate to ammonium conversion is impaired in pdx3 mutants, such that the mutants become ammonium-dependent, suggesting an interaction between vitamin B6 and nitrogen metabolism. In addition, we found a strong up-regulation of genes related to plant defense. Here, we further show that pdx3 mutants display a temperature-sensitive phenotype that is typical of autoimmune mutants and is possibly connected to the impaired nitrogen metabolism.

  18. Structural correlations in bacterial metabolic networks

    Directory of Open Access Journals (Sweden)

    Lizana Ludvig

    2011-01-01

    Full Text Available Abstract Background Evolution of metabolism occurs through the acquisition and loss of genes whose products acts as enzymes in metabolic reactions, and from a presumably simple primordial metabolism the organisms living today have evolved complex and highly variable metabolisms. We have studied this phenomenon by comparing the metabolic networks of 134 bacterial species with known phylogenetic relationships, and by studying a neutral model of metabolic network evolution. Results We consider the 'union-network' of 134 bacterial metabolisms, and also the union of two smaller subsets of closely related species. Each reaction-node is tagged with the number of organisms it belongs to, which we denote organism degree (OD, a key concept in our study. Network analysis shows that common reactions are found at the centre of the network and that the average OD decreases as we move to the periphery. Nodes of the same OD are also more likely to be connected to each other compared to a random OD relabelling based on their occurrence in the real data. This trend persists up to a distance of around five reactions. A simple growth model of metabolic networks is used to investigate the biochemical constraints put on metabolic-network evolution. Despite this seemingly drastic simplification, a 'union-network' of a collection of unrelated model networks, free of any selective pressure, still exhibit similar structural features as their bacterial counterpart. Conclusions The OD distribution quantifies topological properties of the evolutionary history of bacterial metabolic networks, and lends additional support to the importance of horizontal gene transfer during bacterial metabolic evolution where new reactions are attached at the periphery of the network. The neutral model of metabolic network growth can reproduce the main features of real networks, but we observe that the real networks contain a smaller common core, while they are more similar at the periphery

  19. Structural correlations in bacterial metabolic networks.

    Science.gov (United States)

    Bernhardsson, Sebastian; Gerlee, Philip; Lizana, Ludvig

    2011-01-20

    Evolution of metabolism occurs through the acquisition and loss of genes whose products acts as enzymes in metabolic reactions, and from a presumably simple primordial metabolism the organisms living today have evolved complex and highly variable metabolisms. We have studied this phenomenon by comparing the metabolic networks of 134 bacterial species with known phylogenetic relationships, and by studying a neutral model of metabolic network evolution. We consider the 'union-network' of 134 bacterial metabolisms, and also the union of two smaller subsets of closely related species. Each reaction-node is tagged with the number of organisms it belongs to, which we denote organism degree (OD), a key concept in our study. Network analysis shows that common reactions are found at the centre of the network and that the average OD decreases as we move to the periphery. Nodes of the same OD are also more likely to be connected to each other compared to a random OD relabelling based on their occurrence in the real data. This trend persists up to a distance of around five reactions. A simple growth model of metabolic networks is used to investigate the biochemical constraints put on metabolic-network evolution. Despite this seemingly drastic simplification, a 'union-network' of a collection of unrelated model networks, free of any selective pressure, still exhibit similar structural features as their bacterial counterpart. The OD distribution quantifies topological properties of the evolutionary history of bacterial metabolic networks, and lends additional support to the importance of horizontal gene transfer during bacterial metabolic evolution where new reactions are attached at the periphery of the network. The neutral model of metabolic network growth can reproduce the main features of real networks, but we observe that the real networks contain a smaller common core, while they are more similar at the periphery of the network. This suggests that natural selection and

  20. Age dependence of tritium metabolism

    International Nuclear Information System (INIS)

    Inaba, Jiro

    1983-01-01

    3 H metabolism in vivo was studied by HTO administration to rats of varying ages for examination of the age dependence of 3 H metabolism in humans. When 1 μCi/g body weight of HTO was administered, the time-course changes of urine 3 H showed definite age dependence; the younger the rat, more rapidly did the 3 H concentration decrease. The biological half-life of whole body residues was about 2 days in nursing offsprings and about 4 days in mature rats. Tissue-bound 3 H showed high and rapid distribution to the liver, whereas it was slow in the brain and muscle, and this tendency was more prominent in younger rats. Compared with 3 H in tissue water, the concentration of bound 3 H was relatively high, being prominent in younger rats. The time-course changes of 3 H concentration from both origins also showed age dependence. The in vivo exposure dose after administration of 1 μCi/g body weight of HTO- 3 H was generally smaller in younger rats, the exposure at ages 10 and 25 days being about a half of that of mature rats. Supposing that human metabolism is similar, the estimated dose in one-year-olds after ingestion of 1 μCi/kg body weight of 3 H in the form of HTO is about 3 times that in adults, and that after 1 μCi/kg body weight of 3 H in infants, about a half of that in adults. (Chiba, N.)

  1. Does methamphetamine affect bone metabolism?

    International Nuclear Information System (INIS)

    Tomita, Masafumi; Katsuyama, Hironobu; Watanabe, Yoko; Okuyama, Toshiko; Fushimi, Shigeko; Ishikawa, Takaki; Nata, Masayuki; Miyamoto, Osamu

    2014-01-01

    There is a close relationship between the central nervous system activity and bone metabolism. Therefore, methamphetamine (METH), which stimulates the central nervous system, is expected to affect bone turnover. The aim of this study was to investigate the role of METH in bone metabolism. Mice were divided into 3 groups, the control group receiving saline injections, and the 5 and 10 mg/kg METH groups (n = 6 in each group). All groups received an injection of saline or METH every other day for 8 weeks. Bone mineral density (BMD) was assessed by X-ray computed tomography. We examined biochemical markers and histomorphometric changes in the second cancellous bone of the left femoral distal end. The animals that were administered 5 mg/kg METH showed an increased locomotor activity, whereas those receiving 10 mg/kg displayed an abnormal and stereotyped behavior. Serum calcium and phosphorus concentrations were normal compared to the controls, whereas the serum protein concentration was lower in the METH groups. BMD was unchanged in all groups. Bone formation markers such as alkaline phosphatase and osteocalcin significantly increased in the 5 mg/kg METH group, but not in the 10 mg/kg METH group. In contrast, bone resorption markers such as C-terminal telopeptides of type I collagen and tartrate-resistant acid phosphatase 5b did not change in any of the METH groups. Histomorphometric analyses were consistent with the biochemical markers data. A significant increase in osteoblasts, especially in type III osteoblasts, was observed in the 5 mg/kg METH group, whereas other parameters of bone resorption and mineralization remained unchanged. These results indicate that bone remodeling in this group was unbalanced. In contrast, in the 10 mg/kg METH group, some parameters of bone formation were significantly or slightly decreased, suggesting a low turnover metabolism. Taken together, our results suggest that METH had distinct dose-dependent effects on bone turnover and that

  2. Metabolism of fluoroacetate in lettuce

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.F.V.; Huskisson, N.S.

    1972-01-01

    Whole lettuce plants were incubated with (1) (l-/sup 14/C)acetate, (2) fluoroacetate followed by (l-/sup 14/C)acetate, (3) fluoro(l-/sup 14/C)acetate, (4) fluoro(2-/sup 14/C)acetate or (5) S-carboxy-(/sup 14/C)methylglutathione. 2. Fluoroacetate did not affect the expiration of /sup 14/CO/sub 2/ from (l-/sup 14/C)acetate and only a small amount of /sup 14/CO/sub 2/ was produced from either fluoro(l-/sup 14/C)-acetate or fluoro(2-/sup 14/C)acetate in 43 h. 3. Fluoroacetate at 50 mg/kg wet wt. doubled the plant citrate concentration after 43 h incubation, and depending on the age and size of the plant 50-100% of the compound was metabolized. 4. With both fluoro(l-/sup 14/C)acetate and fluoro(2-/sup 14/C)acetate all the radioactivity except that in the CO/sub 2/ was found in the water-soluble fraction. About 2% was in fluorocitrate and the remainder, apart from unchanged fluoroacetate, was in a number of compounds devoid of fluorine but containing nitrogen and sulphur. These were peptide-like and could be separated by chromatography on an amino acid analyser. 5. Identical compounds were obtained from the spontaneous reaction between iodo(2-/sup 14/C)acetate and glutathione, the major product being S-carboxy-methylglutathione. 6. S-Carboxymethylcysteine was also isolated and its mass spectrum compared with a commercial sample. 7. Reaction rates of all the monohaloacetates with glutathione were studied at pH 7 at 25/sup 0/C. No reaction was observed with fluoroacetate. 8. The metabolism of fluoroacetate by lettuce is discussed in relation to that of aliphatic and aromatic halogen compounds, including fluoroacetate, by mammalian liver and to the metabolism of fluoroacetate by different plants reported by other workers.

  3. Metabolic Imaging in Parkinson Disease.

    Science.gov (United States)

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

    2017-01-01

    This review focuses on recent human 18 F-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 18 F-FDG PET studies have advanced understanding of the relation between distinct brain regions and associated symptoms in Parkinson disease, including cognitive decline. In addition, the value of 18 F-FDG PET studies in differential diagnosis, identifying prodromal patients, and the evaluation of treatment effects are reviewed. Finally, anticipated developments in the field are addressed. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  4. 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.

  5. 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.

  6. Glucose metabolism in ischemic myocardium

    International Nuclear Information System (INIS)

    Takahashi, Akira; Ono, Yukihiko; Sudo, Makiko; Araki, Kazuhiro; Shishido, Fumio; Uemura, Kazuo; Kadowaki, Ken; Kumagai, Tadayuki.

    1986-01-01

    We determined the myocardial metabolic rate for glucose (MMRGlc) in the ischemic or infarcted myocardium using 18-F-fluorodeoxyglucose (18-FDG) with positron emission tomography (PET), and studied energy metabolism in the ischemic myocardium. In some cases, we compared glucose metabolism images by 18-FDG with myocardial blood flow images using 15-oxygen water. Two normal subjects, seven patients with myocardial infarction and four patients with angina pectoris were studied. Coronary angiography was performed within two weeks before or after the PET study to detect ischemic areas. PET studies were performed for patients who did not eat for 5 to 6 hours after breakfast. Cannulation was performed in the pedal artery to measure free fatty acid, blood sugar, and insulin. After recording the transmission scan for subsequent correction of photon attenuation, blood pool images were recorded for two min. after the inhalation of carbon monoxide (oxygen-15) which labeled the red blood cells in vivo. After 20 min., oxygen-15 water (15 to 20 mCi) was injected for dynamic scans, and flow images were obtained. Thirty min. after this procedure, 18-FDG (5 to 6 mCi) was injected, and 60 min later, a static scan was performed and glucose metabolism images were obtained. Arterial blood sampling for the time activity curve of the tracer was performed at the same time. According to the method of Phelps et al, MMRGlc was calculated in each of the region of interest (ROI) which was located in the left ventricular wall. MMRGlc obtained from each ROI was 0 to 17 mg/100 ml/min. In normal subjects MMRGlc was 0.4 to 7.3 mg/100 ml/min. In patients with myocardial infarction, it ranged from 3 to 5 mg/100 ml/min in the infarcted lesion. In patients with angina pectoris and subendocardial infarction, MMRGlc was 7 to 17 mg/100 ml/min in the ischemic lesion. In this lesion, myocardial blood flow was relatively low by oxygen-15 imagings (so-called mismatch). (J.P.N.)

  7. Lipid metabolism in cancer cachexia.

    OpenAIRE

    Mulligan, H. D.; Beck, S. A.; Tisdale, M. J.

    1992-01-01

    The effect of cancer cachexia on the oxidative metabolism of lipids has been studied in mice transplanted either with the MAC16 adenocarcinoma, which induces profound loss of body weight and depletion of lipid stores, or the MAC13 adenocarcinoma, which is the same histological type, but which grows without an effect on host body weight or lipid stores. While oxidation of D-[U-14C]glucose did not differ between animals bearing tumours of either type and non-tumour bearing controls, oxidation o...

  8. Metabolic effects of contraceptive steroids.

    Science.gov (United States)

    Sitruk-Ware, Regine; Nath, Anita

    2011-06-01

    Estrogen and progestins have been used by millions of women as effective combined contraceptives. The safety of hormonal contraceptives has been documented by years of follow-up and serious adverse events that may be related to their use are rare in the young population exposed to these agents. The balance between the benefits and the risks of contraceptive steroids is generally positive in particular when comparing to the risks of pregnancy and especially in women with risk factors. The metabolic changes induced by the synthetic steroids used in contraception, such as lipoprotein changes, insulin response to glucose, and coagulation factors have been considered as potential markers of cardiovascular and venous risk. Observations of these effects have led to modifications of the composition of hormonal contraceptive in order to minimize these changes and hence potentially decrease the risks. The synthetic estrogen Ethinyl-Estradiol (EE) exerts a stronger effect that natural estradiol (E2) on hepatic metabolism including estrogen-dependent markers such as liver proteins. This stronger hepatic impact of EE has been related to its 17α-ethinyl group which prevents the inactivation of the molecule and results in a more pronounced hepatic effect of EE as compared to estradiol. Due to its strong activity, administering EE via a non-oral route does not prevent its impact on liver proteins. In order to circumvent the metabolic changes induced by EE, newer products using more natural compounds such as estradiol (E2) and estradiol valerate (E2V) have been introduced. The synthetic progestins used for contraception are structurally related either to testosterone (T) (estranes and gonanes) or to progesterone (pregnanes and 19-norpregnanes). Several new progestins have been designed to bind more specifically to the progesterone receptor and to minimize side-effects related to androgenic, estrogenic or glucocorticoid receptor interactions. Dienogest (DNG), and drospirenone (DRSP

  9. 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.

  10. Metabolic Syndrome, Obesity, and Gastrointestinal Cancer

    Directory of Open Access Journals (Sweden)

    Shintaro Fujihara

    2012-01-01

    Full Text Available Metabolic syndrome is a cluster of metabolic abnormalities and is defined as the presence of three or more of the following factors: increased waist circumference, elevated triglycerides, low high-density lipoprotein cholesterol, high blood pressure, and high fasting glucose. Obesity, which is accompanied by metabolic dysregulation often manifested in the metabolic syndrome, is an established risk factor for many cancers. Adipose tissue, particularly visceral fat, is an important metabolic tissue as it secretes systemic factors that alter the immunologic, metabolic, and endocrine milieu and also promotes insulin resistance. Within the growth-promoting, proinflammatory environment of the obese state, cross-talk between macrophages, adipocytes, and epithelial cells occurs via obesity-associated hormones, adipocytokines, and other mediators that may enhance cancer risk and progression. This paper synthesizes the evidence on key molecular mechanisms underlying the obesity-cancer link.

  11. Metabolism of xenobiotics of human environments.

    Science.gov (United States)

    Croom, Edward

    2012-01-01

    Xenobiotics have been defined as chemicals to which an organism is exposed that are extrinsic to the normal metabolism of that organism. Without metabolism, many xenobiotics would reach toxic concentrations. Most metabolic activity inside the cell requires energy, cofactors, and enzymes in order to occur. Xenobiotic-metabolizing enzymes can be divided into phase I, phase II, and transporter enzymes. Lipophilic xenobiotics are often first metabolized by phase I enzymes, which function to make xenobiotics more polar and provide sites for conjugation reactions. Phase II enzymes are conjugating enzymes and can directly interact with xenobiotics but more commonly interact with metabolites produced by phase I enzymes. Through both passive and active transport, these more polar metabolites are eliminated. Most xenobiotics are cleared through multiple enzymes and pathways. The relationship between chemical concentrations, enzyme affinity and quantity, and cofactor availability often determine which metabolic reactions dominate in a given individual. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. 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.

  13. Metabolic biomarkers related to energy metabolism in Saudi autistic children.

    Science.gov (United States)

    Al-Mosalem, O A; El-Ansary, A; Attas, O; Al-Ayadhi, L

    2009-07-01

    Energy metabolism is usually manipulated in many neurodegenerative diseases. Autism is considered a definable systemic disorder resulting in a number of diverse factors that may affect the brain development and functions both pre and post natal. The increased prevalence of autism will have enormous future public implications and has stimulated intense research into potential etiologic factors. This study aims to establish a connection between autism and the deterioration accompanied it, especially in the brain cognitive areas through a postulation of energy manipulation. The biochemical changes in activities of enzymes and pathways that participate in the production of ATP as the most important high-energy compound needed by the human brain were measured in Saudi autistic children. Na(+)/K(+)ATPase, ectonucleotidases (NTPDases) (ADPase and ATPase) and creatine kinase (CK), were assessed in plasma of 30 Saudi autistic patients and compared to 30 age-matching control samples. In addition, adenosine mono, di and trinucleotides (ATP, ADP, and AMP) were measured calorimetrically in the red blood cells of both groups and the adenylate energy charge (AEC) was calculated. Moreover, lactate concentration in plasma of both groups was monitored. The obtained data recorded 148.77% and 72.35% higher activities of Na(+)/K(+)ATPase and CK respectively in autistic patients which prove the impairment of energy metabolism in these children compared to age and sex matching healthy controls. While ADPase was significantly higher in autistic patients, ATPase were non-significantly elevated compared to control. In spite of the significant increase of Na(+)/K(+)ATPase activity in autistic patients, there was no significant difference in the levels of ATP, ADP, and AMP in both groups and the calculated AEC values were 0.814+/-0.094 and 0.806+/-0.081 for autistic and control groups respectively. The unchanged AEC value in autistic patients was easily correlated with the induced activity of

  14. Novel metabolic pathways in Archaea.

    Science.gov (United States)

    Sato, Takaaki; Atomi, Haruyuki

    2011-06-01

    The Archaea harbor many metabolic pathways that differ to previously recognized classical pathways. Glycolysis is carried out by modified versions of the Embden-Meyerhof and Entner-Doudoroff pathways. Thermophilic archaea have recently been found to harbor a bi-functional fructose-1,6-bisphosphate aldolase/phosphatase for gluconeogenesis. A number of novel pentose-degrading pathways have also been recently identified. In terms of anabolic metabolism, a pathway for acetate assimilation, the methylaspartate cycle, and two CO2-fixing pathways, the 3-hydroxypropionate/4-hydroxybutyrate cycle and the dicarboxylate/4-hydroxybutyrate cycle, have been elucidated. As for biosynthetic pathways, recent studies have clarified the enzymes responsible for several steps involved in the biosynthesis of inositol phospholipids, polyamine, coenzyme A, flavin adeninedinucleotide and heme. By examining the presence/absence of homologs of these enzymes on genome sequences, we have found that the majority of these enzymes and pathways are specific to the Archaea. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Ageing, metabolism and cardiovascular disease.

    Science.gov (United States)

    Costantino, Sarah; Paneni, Francesco; Cosentino, Francesco

    2016-04-15

    Age is one of the major risk factors associated with cardiovascular disease (CVD). About one-fifth of the world population will be aged 65 or older by 2030, with an exponential increase in CVD prevalence. It is well established that environmental factors (overnutrition, smoking, pollution, sedentary lifestyles) may lead to premature defects in mitochondrial functionality, insulin signalling, endothelial homeostasis and redox balance, fostering early senescent features. Over the last few years, molecular investigations have unveiled common signalling networks which may link the ageing process with deterioration of cardiovascular homeostasis and metabolic disturbances, namely insulin resistance. These different processes seem to be highly interconnected and their interplay may favour adverse vascular and cardiac phenotypes responsible for myocardial infarction, stroke and heart failure. In the present review, we carefully describe novel molecular cues underpinning ageing, metabolism and CVD. In particular, we describe a dynamic interplay between emerging pathways such as FOXOs, AMPK, SIRT1, p66(Shc) , JunD and NF-kB. This overview will provide the background for attractive molecular targets to prevent age-driven pathology in the vasculature and the heart. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  17. Neuron-glia metabolic coupling and plasticity

    OpenAIRE

    Magistretti PJ

    2011-01-01

    Abstract The focus of the current research projects in my laboratory revolves around the question of metabolic plasticity of neuron glia coupling. Our hypothesis is that behavioural conditions such as for example learning or the sleep wake cycle in which synaptic plasticity is well documented or during specific pathological conditions are accompanied by changes in the regulation of energy metabolism of astrocytes. We have indeed observed that the 'metabolic profile' of astrocytes is modified...

  18. A Quick Reference on Metabolic Alkalosis.

    Science.gov (United States)

    Foy, Daniel S; de Morais, Helio Autran

    2017-03-01

    Metabolic alkalemia is characterized by an increase in bicarbonate concentration and base excess, an increase in pH, and a compensatory increase in carbon dioxide pressure. This article outlines indications for analysis, reference ranges, causes, and clinical signs of metabolic alkalosis. Algorithms for evaluation of patients with acid-base disorders and metabolic alkalosis are included. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. 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...

  20. New research developments and insights from Metabolism

    OpenAIRE

    Farr, Olivia M.; Camp, Michelle; Mantzoros, Christos S.

    2014-01-01

    In a field of great importance to daily life and clinical care, metabolic-related research covers a wealth of information and knowledge. This broad field encompasses a number of physical states that are increasingly critical to study, including obesity, type 2 diabetes, metabolic syndrome, and cardiovascular disease. Additionally, the impacts of diet, nutrition, and exercise on these physical states are an area of ever-important and expanding research. With the latest advances in metabolic re...

  1. Metabolic syndrome in fixed-shift workers

    OpenAIRE

    Raquel Canuto; Marcos Pascoal Pattussi; Jamile Block Araldi Macagnan; Ruth Liane Henn; Maria Teresa Anselmo Olinto

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic ...

  2. Metabolic syndrome in fixed-shift workers

    OpenAIRE

    Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers.METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (...

  3. Principles for circadian orchestration of metabolic pathways

    OpenAIRE

    Thurley, Kevin; Herbst, Christopher; Wesener, Felix; Koller, Barbara; Wallach, Thomas; Maier, Bert; Kramer, Achim; Westermark, Pål O

    2017-01-01

    Circadian (24-h) rhythms influence the behavior and physiology of many organisms. These rhythms are generated at the gene expression level, causing the waxing and waning of protein abundances. Metabolic enzymes are affected, but the principles for the propagation of enzyme rhythmicity to cellular metabolism as quantified by fluxes through metabolic pathways and metabolite concentrations are not understood. We used the mathematics of chemical kinetics to systematically investigate how rhythms ...

  4. Increasing Prevalence of Metabolic Syndrome in Korea

    OpenAIRE

    Lim, Soo; Shin, Hayley; Song, Jung Han; Kwak, Soo Heon; Kang, Seon Mee; Won Yoon, Ji; Choi, Sung Hee; Cho, Sung Il; Park, Kyong Soo; Lee, Hong Kyu; Jang, Hak Chul; Koh, Kwang Kon

    2011-01-01

    OBJECTIVE The number of people with metabolic syndrome is increasing worldwide, and changes in socioenvironmental factors contribute to this increase. Therefore, investigation of changes in metabolic syndrome and its components in South Korea, where rapid socioenvironmental changes have occurred in recent years, would be foundational in setting up an effective strategy for reducing this increasing trend. RESEARCH DESIGN AND METHODS We compared the prevalence and pattern of metabolic syndrome ...

  5. Controlling fluxes for microbial metabolic engineering

    OpenAIRE

    Sachdeva, Gairik

    2014-01-01

    This thesis presents novel synthetic biology tools and design principles usable for microbial metabolic engineering. Controlling metabolic fluxes is essential for biological manufacturing of fuels, materials, and high value chemicals. Insulating the flow of metabolites is a successful natural strategy for metabolic flux regulation. Recently, approaches using scaffolds, both in vitro and in vivo, to spatially co-localize enzymes have reported significant gains in product yields. RNA is suitabl...

  6. Oncometabolites: linking altered metabolism with cancer

    Science.gov (United States)

    Yang, Ming; Soga, Tomoyoshi; Pollard, Patrick J.

    2013-01-01

    The discovery of cancer-associated mutations in genes encoding key metabolic enzymes has provided a direct link between altered metabolism and cancer. Advances in mass spectrometry and nuclear magnetic resonance technologies have facilitated high-resolution metabolite profiling of cells and tumors and identified the accumulation of metabolites associated with specific gene defects. Here we review the potential roles of such “oncometabolites” in tumor evolution and as clinical biomarkers for the detection of cancers characterized by metabolic dysregulation. PMID:23999438

  7. 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.

  8. Hearing Loss, Dizziness, and Carbohydrate Metabolism

    OpenAIRE

    Albernaz, Pedro L. Mangabeira

    2015-01-01

    Abstract Introduction Metabolic activity of the inner ear is very intense, and makes it sensitive to changes in the body homeostasis. This study involves a group of patients with inner ear disorders related to carbohydrate metabolism disturbances, including hearing loss, tinnitus, dizziness, and episodes of vertigo. Objectives To describe the symptoms of metabolic inner ear disorders and the examinations required to establish diagnoses. These symptoms are often the first to allow for an e...

  9. 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....

  10. Applications of NMR in biological metabolic research

    International Nuclear Information System (INIS)

    Nie Jiarui; Li Xiuqin; He Chunjian

    1989-01-01

    The nuclear magnetic resonance has become a powerful means of studying biological metabolism in non-invasive and non-destructive way. Being used to study the metabolic processes of living system in normal physiological conditions as well as in molecular level, the method is better than other conventional approaches. Using important parameters such as NMR-chemical shifts, longitudinal relaxation time and transverse relaxation time, it is possible to probe the metabolic processes as well as conformation, concentration, transportation and distribution of reacting and resulting substances. The NMR spectroscopy of 1 H, 31 P and 13 C nuclei has already been widely used in metabolic researches

  11. Clinical neurogenetics: neurologic presentations of metabolic disorders.

    Science.gov (United States)

    Kwon, Jennifer M; D'Aco, Kristin E

    2013-11-01

    This article reviews aspects of the neurologic presentations of selected treatable inborn errors of metabolism within the category of small molecule disorders caused by defects in pathways of intermediary metabolism. Disorders that are particularly likely to be seen by neurologists include those associated with defects in amino acid metabolism (organic acidemias, aminoacidopathies, urea cycle defects). Other disorders of small molecule metabolism are discussed as additional examples in which early treatments have the potential for better outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Finding metabolic pathways using atom tracking

    Science.gov (United States)

    Heath, Allison P.; Bennett, George N.; Kavraki, Lydia E.

    2010-01-01

    Motivation: Finding novel or non-standard metabolic pathways, possibly spanning multiple species, has important applications in fields such as metabolic engineering, metabolic network analysis and metabolic network reconstruction. Traditionally, this has been a manual process, but the large volume of metabolic data now available has created a need for computational tools to automatically identify biologically relevant pathways. Results: We present new algorithms for finding metabolic pathways, given a desired start and target compound, that conserve a given number of atoms by tracking the movement of atoms through metabolic networks containing thousands of compounds and reactions. First, we describe an algorithm that identifies linear pathways. We then present a new algorithm for finding branched metabolic pathways. Comparisons to known metabolic pathways demonstrate that atom tracking enables our algorithms to avoid many unrealistic connections, often found in previous approaches, and return biologically meaningful pathways. Our results also demonstrate the potential of the algorithms to find novel or non-standard pathways that may span multiple organisms. Availability: The software is freely available for academic use at: http://www.kavrakilab.org/atommetanet Contact: kavraki@rice.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20421197

  13. Fibroblast Growth Factor Signaling in Metabolic Regulation.

    Science.gov (United States)

    Nies, Vera J M; Sancar, Gencer; Liu, Weilin; van Zutphen, Tim; Struik, Dicky; Yu, Ruth T; Atkins, Annette R; Evans, Ronald M; Jonker, Johan W; Downes, Michael Robert

    2015-01-01

    The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance, and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed. In this review, we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also, the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease and to provide starting points for the development of FGF-based therapies against metabolic conditions.

  14. Diacylglycerol oil for the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Yoshida Hiroshi

    2007-12-01

    Full Text Available Abstract Excess adiposity has been shown to play a crucial role in the development of the metabolic syndrome. The elevated fasting and postprandial triglyceride-rich lipoprotein levels is the central lipid abnormality observed in the metabolic syndrome. Recent studies have indicated that diacylglycerol (DAG is effective for fasting and postprandial hyperlipidemia and preventing excess adiposity by increasing postprandial energy expenditure. We will here discuss the mechanisms of DAG-mediated improvements in hyperlipidemia and in postprandial energy expenditure, and effects of DAG oil on lipid/glucose metabolism and on body fat. Further, the therapeutic application of DAG for the metabolic syndrome will be considered.

  15. Stimulation-induced cerebral glycolytic glucose metabolism

    International Nuclear Information System (INIS)

    Ackermann, R.F.; Lear, J.L.

    1989-01-01

    The authors have developed a method to estimate the relative amounts of cerebral oxidative and glycolytic glucose metabolism with sequentially administered radiolabeled fluorode-oxyglucose (FDG) and 6-glucose (GLU). Cerebral FDG metabolite concentration was found to reflect total glucose metabolism. Cerebral GLU metabolite concentration, however, was found to reflect mainly oxidative metabolism, because of significant fraction of the radiolabel was lost through lactate production and diffusion from the brain with glycolysis. The authors applied the method to normal rats, to seizing rats, and to optically stimulated rats. Normal cerebral glucose metabolism was primarily oxidative, but stimulation caused profound increases in glycolysis in activated brain regions

  16. 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.

  17. Targeting glucose metabolism in patients with cancer.

    Science.gov (United States)

    Elf, Shannon E; Chen, Jing

    2014-03-15

    Nearly a century ago, Otto Warburg made the astute observation that the metabolic properties of cancer cells differ markedly from those of normal cells. Several decades passed before the concept of exploiting cancer cell metabolism came into clinical practice with the advent of chemotherapy, the underlying principle of which is to target rapidly dividing cells by interfering with critical processes that are all, on some level, driven by cell metabolism. Although chemotherapy can be quite effective, success rates are highly variable and the adverse effects associated with treatment often outweigh the benefits due to the fact that chemotherapy is indiscriminately cytotoxic against all rapidly dividing cells, cancerous or healthy. During the past several years, a more intricate understanding of cancer cell metabolism has permitted the development of targeted therapies that aim to specifically target cancer cells and spare healthy tissue by exploiting the altered metabolism of cancer cells. The identification of new metabolic targets and the subsequent development of small-molecule inhibitors of metabolic enzymes have demonstrated the utility and promise of targeting cancer cell metabolism as an anticancer strategy. This review summarizes recent advances in the identification and characterization of several metabolic enzymes as emerging anticancer targets. © 2013 American Cancer Society.

  18. Metabolic, endocrine, and related bone diseases

    International Nuclear Information System (INIS)

    Rogers, L.F.

    1987-01-01

    Bone is living tissue, and old bone is constantly removed and replaced with new bone. Normally this exchange is in balance, and the mineral content remains relatively constant. This balance may be disturbed as a result of certain metabolic and endocrinologic disorders. The term dystrophy, referring to a disturbance of nutrition, is applied to metabolic and endocrine bone diseases and should be distinguished from the term dysplasia, referring to a disturbance of bone growth. The two terms are easily confused but are not interchangeable. Metabolic bone disease is caused by endocrine imbalance, vitamin deficiency or excess, and other disturbances in bone metabolism leading to osteoporosis and osteomalacia

  19. [Determination of minimal concentrations of biocorrosion inhibitors by a bioluminescence method in relation to bacteria, participating in biocorrosion].

    Science.gov (United States)

    Efremenko, E N; Azizov, R E; Makhlis, T A; Abbasov, V M; Varfolomeev, S D

    2005-01-01

    By using a bioluminescence ATP assay, we have determined the minimal concentrations of some biocorrosion inhibitors (Katon, Khazar, VFIKS-82, Nitro-1, Kaspii-2, and Kaspii-4) suppressing most common microbial corrosion agents: Desulfovibrio desulfuricans, Desulfovibrio vulgaris, Pseudomonas putida, Pseudomonas fluorescens, and Acidithiobacillus ferrooxidans. The cell titers determined by the bioluminescence method, including not only dividing cells but also their dormant living counterparts, are two- to sixfold greater than the values determined microbiologically. It is shown that the bioluminescence method can be applied to determination of cell titers in samples of oil-field waters in the presence of iron ions (up to 260 mM) and iron sulfide (to 186 mg/l) and in the absence or presence of biocidal corrosion inhibitors.

  20. Identificação e isolamento de bactérias envolvidas na formação de drenagem ácida mineira na região de Jacobina (Bahia) e o seu uso na biolixiviação de cobre

    OpenAIRE

    Oliveira, Luiz Eduardo Lacerda de

    2013-01-01

    Acidithiobacillus ferrooxidans é uma das bactérias catalizadoras da reação de oxidação que leva à formação drenagem ácida mineira (DAM). Devido à capacidade oxidativa e lixiviante deste micro-organismo, a indústria passou a usá-lo na extração de minerais, por biolixiviação, com vantagens em relação aos métodos convencionais em alguns casos. A Bahia tem uma expressiva produção mineral, no entanto poucos são os relatos sobre a investigação sistemática de aspectos microbiológicos envolvidos na D...

  1. Microbial pathways for the mobilization of mercury as Hg(O) in anoxic subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Barkay, Tamar

    2005-06-01

    The goal of our project which was initiated in June 2005 is focused on the presence of merA in microbial communities of anoxic environments and the effect of anaerobic respiratory pathways on MR expression and activities. The following progress has been made to date: PCR primers were designed to span the known phylogenetic range of merA genes of Gram-negative bacteria. In control experiments, these primers successfully amplified a 288 bp region at the 3? end of previously characterized merA genes from Shewanella putrefaciens pMERPH, Acidithiobacillus ferrooxidans, Pseudomonas stutzeri pPB, Tn5041, Pseudomonas sp. K-62, and Serratia marcescens pDU1358.

  2. Integration of Genome Scale Metabolic Networks and Gene Regulation of Metabolic Enzymes With Physiologically Based Pharmacokinetics

    Science.gov (United States)

    Maldonado, Elaina M.; Leoncikas, Vytautas; Fisher, Ciarán P.; Moore, J. Bernadette; Plant, Nick J.

    2017-01-01

    The scope of physiologically based pharmacokinetic (PBPK) modeling can be expanded by assimilation of the mechanistic models of intracellular processes from systems biology field. The genome scale metabolic networks (GSMNs) represent a whole set of metabolic enzymes expressed in human tissues. Dynamic models of the gene regulation of key drug metabolism enzymes are available. Here, we introduce GSMNs and review ongoing work on integration of PBPK, GSMNs, and metabolic gene regulation. We demonstrate example models. PMID:28782239

  3. 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.

  4. 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.

  5. Microbial Metabolism in Serpentinite Fluids

    Science.gov (United States)

    Crespo-Medina, M.; Brazelton, W. J.; Twing, K. I.; Kubo, M.; Hoehler, T. M.; Schrenk, M. O.

    2013-12-01

    Serpentinization is the process in which ultramafic rocks, characteristic of the upper mantle, react with water liberating mantle carbon and reducing power to potenially support chemosynthetic microbial communities. These communities may be important mediators of carbon and energy exchange between the deep Earth and the surface biosphere. Our work focuses on the Coast Range Ophiolite Microbial Observatory (CROMO) in Northern California where subsurface fluids are accessible through a series of wells. Preliminary analyses indicate that the highly basic fluids (pH 9-12) have low microbial diversity, but there is limited knowledge about the metabolic capabilities of these communties. Metagenomic data from similar serpentine environments [1] have identified Betaproteobacteria belonging to the order Burkholderiales and Gram-positive bacteria from the order Clostridiales as key components of the serpentine microbiome. In an effort to better characterize the microbial community, metabolism, and geochemistry at CROMO, fluids from two representative wells (N08B and CSWold) were sampled during recent field campaigns. Geochemical characterization of the fluids includes measurements of dissolved gases (H2, CO, CH4), dissolved inorganic and organic carbon, volatile fatty acids, and nutrients. The wells selected can be differentiated in that N08B had higher pH (10-11), lower dissolved oxygen, and cell counts ranging from 105-106 cells mL-1 of fluid, with an abundance of the betaproteobacterium Hydrogenophaga. In contrast, fluids from CSWold have slightly lower pH (9-9.5), DO, and conductivity, as well as higher TDN and TDP. CSWold fluid is also characterized for having lower cell counts (~103 cells mL-1) and an abundance of Dethiobacter, a taxon within the phylum Clostridiales. Microcosm experiments were conducted with the purpose of monitoring carbon fixation, methanotrophy and metabolism of small organic compounds, such as acetate and formate, while tracing changes in fluid

  6. 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

  7. 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.

  8. Pyruvate Kinase Triggers a Metabolic Feedback Loop that Controls Redox Metabolism in Respiring Cells

    NARCIS (Netherlands)

    Grüning, N.M.; Rinnerthaler, M.; Bluemlein, K.; Mulleder, M.; Wamelink, M.M.C.; Lehrach, H.; Jakobs, C.A.J.M.; Breitenbach, M.; Ralser, M.

    2011-01-01

    In proliferating cells, a transition from aerobic to anaerobic metabolism is known as the Warburg effect, whose reversal inhibits cancer cell proliferation. Studying its regulator pyruvate kinase (PYK) in yeast, we discovered that central metabolism is self-adapting to synchronize redox metabolism

  9. 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.

  10. [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.

  11. Metabolic effects of smoking cessation

    Science.gov (United States)

    Harris, Kindred K.; Zopey, Mohan; Friedman, Theodore C.

    2016-01-01

    Smoking continues to be the leading cause of preventable death in the USA, despite the vast and widely publicized knowledge about the negative health effects of tobacco smoking. Data show that smoking cessation is often accompanied by weight gain and an improvement in insulin sensitivity over time. However, paradoxically, post-cessation-related obesity might contribute to insulin resistance. Furthermore, post-cessation weight gain is reportedly the number one reason why smokers, especially women, fail to initiate smoking cessation or relapse after initiating smoking cessation. In this Review, we discuss the metabolic effects of stopping smoking and highlight future considerations for smoking cessation programs and therapies to be designed with an emphasis on reducing post-cessation weight gain. PMID:26939981

  12. Tritium metabolism in rat tissues

    International Nuclear Information System (INIS)

    Takeda, H.

    1982-01-01

    As part of a series of studies designed to evaluate the relative radiotoxicity of various tritiated compounds, metabolism of tritium in rat tissues was studied after administration of tritiated water, leucine, thymidine, and glucose. The distribution and retention of tritium varied widely, depending on the chemical compound administered. Tritium introduced as tritiated water behaved essentially as body water and became uniformly distributed among the tissues. However, tritium administered as organic compounds resulted in relatively high incorporation into tissue constituents other than water, and its distribution differed among the various tissues. Moreover, the excretion rate of tritium from tissues was slower for tritiated organic compounds than for tritiated water. Administrationof tritiated organic compounds results in higher radiation doses to the tissues than does administration of tritiated water. Among the tritiated compounds examined, for equal radioactivity administered, leucine gave the highest radiation dose, followed in turn by thymidine, glucose, and water. (author)

  13. Metabolism of organically bound tritium

    International Nuclear Information System (INIS)

    Travis, C.C.

    1984-01-01

    The classic methodology for estimating dose to man from environmental tritium ignores the fact that organically bound tritium in foodstuffs may be directly assimilated in the bound compartment of tissues without previous oxidation. We propose a four-compartment model consisting of a free body water compartment, two organic compartments, and a small, rapidly metabolizing compartment. The utility of this model lies in the ability to input organically bound tritium in foodstuffs directly into the organic compartments of the model. We found that organically bound tritium in foodstuffs can increase cumulative total body dose by a factor of 1.7 to 4.5 times the free body water dose alone, depending on the bound-to-loose ratio of tritium in the diet. Model predictions are compared with empirical measurements of tritium in human urine and tissue samples, and appear to be in close agreement. 10 references, 4 figures, 3 tables

  14. 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.

  15. Triglyceride metabolism in exercising muscle.

    Science.gov (United States)

    Watt, Matthew J; Cheng, Yunsheng

    2017-10-01

    Triglycerides are stored within lipid droplets in skeletal muscle and can be hydrolyzed to produce fatty acids for energy production through β-oxidation and oxidative phosphorylation. While there was some controversy regarding the quantitative importance of intramyocellular triglyceride (IMTG) as a metabolic substrate, recent advances in proton magnetic resonance spectroscopy and confocal microscopy support earlier tracer and biopsy studies demonstrating a substantial contribution of IMTG to energy production, particularly during moderate-intensity endurance exercise. This review provides an update on the understanding of IMTG utilization during exercise, with a focus on describing the key regulatory proteins that control IMTG breakdown and how these proteins respond to acute exercise and in the adaptation to exercise training. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Phytosterols, Phytostanols, and Lipoprotein Metabolism

    Directory of Open Access Journals (Sweden)

    Helena Gylling

    2015-09-01

    Full Text Available The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%–10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein

  17. Phytosterols, Phytostanols, and Lipoprotein Metabolism.

    Science.gov (United States)

    Gylling, Helena; Simonen, Piia

    2015-09-17

    The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL) cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%-10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a) or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL) cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein particles will be

  18. 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

  19. [Carotenoids: 1. Metabolism and physiology].

    Science.gov (United States)

    Faure, H; Fayol, V; Galabert, C; Grolier, P; Le Moël, G; Steghens, J P; Van Kappel, A; Nabet, F

    1999-01-01

    Carotenoids are a family of pigments with at least 600 members. They derive from lycopene after steps of cyclisation, dehydrogenation and oxidation. It is their chemical structure that determines their physiochemical properties and, in part, their biological activities. About 50 carotenoids can be found in human diet and about 20 of them have been found in plasma and tissues. There is no RDA (Recommended Daily Allowance) for carotenoids. Quantities of carotenoids in diet are difficult to estimate, partly because methods used for the establishment of food composition tables were not specific and sensitive enough. Also, given values do not always take into account variations due to season and region of culture. Absorption of beta-carotene in humans has been the subject of numerous studies but only very little is known about other carotenoids. In general, absorption depends on bioavailability from the food matrix and solubility in micelles. After absorption through passive diffusion, carotenoids follow the chylomicrons metabolism. They are taken up by the liver and released in the blood stream in lipoproteins (VLDL). Carotenoids with no-substituted beta-ionone cycles (alpha and beta-carotene and beta-cryptoxanthin) have provitamin A activity. Highest activity has been found for all-trans beta-carotene. Not all steps of vitamin A biosynthesis and metabolism of other carotenoids have been clarified yet. Besides their provitamin A activity, carotenoids have numerous biological functions. They are efficient scavengers of free radicals, particularly of 1O2. In vitro they have been shown to protect LDL. However, results in vivo are inconsistent. Other functions include enhancement of gap junctions, immunomodulation and regulation of enzyme activity involved in carcinogenesis.

  20. Metabolism of elements in Japanese

    International Nuclear Information System (INIS)

    Uchiyama, Masafumi

    1990-01-01

    The metabolism of cesium and iodine in Japanese is reviewed regarding with assessing the internal dose from their radioisotopes. Cesium: A two-component model can depict the time-relating retention in the whole-body. The half-time in adult male is shorter for Japanese than for the ICRP Reference Man. The half-time is shorter in woman and shortest in infants. The difference in half-time between Japanese and Caucasian becomes larger with aging. The half-time is successfully related with other biological parameters. A use of the estimation model for biological half-time by Cryer and Baverstock is recommendable for Japanese. The cesium half-time has a wide difference as mush as 3 times among individuals even within the limited sexual and age-group. Iodine: ICRP recommended a model of iodine for Reference Man. However, uptake of iodine in thyroid depends on the concentration of iodine in blood in the same way as with the half-time. It is indicated that concentration of thyroxine in blood is kept constant when thyroid has an extraordinary amount of iodine supply. The amount of stable iodine in thyroid indicated no difference between Japanese and Caucasian. Considering these characteristic conditions for Japanese, a model was established in which another route for the release of inorganic iodine from thyroid is included beside those assumed in the ICRP model. The estimated half-time agreed with the observed values in Japanese who were administered iodine-131. The observed smaller uptake of iodine in thyroid for Japanese was also well explained. The uptake begins around 13 weeks after conception and increases with age upto the time of delivery. The rate of metabolism in newborn is 3 times higher than in adult. The biological half-time in thyroid increases with age. (author)

  1. RESISTANT HYPERTENSION IN A PATIENT WITH METABOLIC SYNDROME

    OpenAIRE

    O. M. Drapkina; J. S. Sibgatullina

    2016-01-01

    Clinical case of resistant hypertension in a patient with metabolic syndrome is presented. Features of hypertension in metabolic syndrome and features of metabolic syndrome in women of pre- and postmenopausal age are also considered. Understanding the features of metabolic syndrome in women, as well as features of hypertension and metabolic syndrome will improve the results of treatment in patients with resistant hypertension.

  2. Microbial Diversity and Its Relationship to Physicochemical Characteristics of the Water in Two Extreme Acidic Pit Lakes from the Iberian Pyrite Belt (SW Spain.

    Directory of Open Access Journals (Sweden)

    Esther Santofimia

    Full Text Available The Iberian Pyrite Belt (IPB hosts one of the world's largest accumulations of acidic mine wastes and pit lakes. The mineralogical and textural characteristics of the IPB ores have favored the oxidation and dissolution of metallic sulfides, mainly pyrite, and the subsequent formation of acidic mining drainages. This work reports the physical properties, hydrogeochemical characteristics, and microbial diversity of two pit lakes located in the IPB. Both pit lakes are acidic and showed high concentrations of sulfate and dissolved metals. Concentrations of sulfate and heavy metals were higher in the Nuestra Señora del Carmen lake (NSC by one order of magnitude than in the Concepción (CN lake. The hydrochemical characteristics of NSC were typical of acid mine waters and can be compared with other acidic environments. When compared to other IPB acidic pit lakes, the superficial water of CN is more diluted than that of any of the others due, probably, to the strong influence of runoff water. Both pit lakes showed chemical and thermal stratification with well defined chemoclines. One particular characteristic of NSC is that it has developed a chemocline very close to the surface (2 m depth. Microbial community composition of the water column was analyzed by 16S and 18S rRNA gene cloning and sequencing. The microorganisms detected in NSC were characteristic of acid mine drainage (AMD, including iron oxidizing bacteria (Leptospirillum, Acidithiobacillus ferrooxidans and facultative iron reducing bacteria and archaea (Acidithiobacillus ferrooxidans, Acidiphilium, Actinobacteria, Acidimicrobiales, Ferroplasma detected in the bottom layer. Diversity in CN was higher than in NSC. Microorganisms known from AMD systems (Acidiphilium, Acidobacteria and Ferrovum and microorganisms never reported from AMD systems were identified. Taking into consideration the hydrochemical characteristics of these pit lakes and the spatial distribution of the identified

  3. Bacteria-assisted preparation of nano α-Fe{sub 2}O{sub 3} red pigment powders from waste ferrous sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang; Wang, Chuankai; Zeng, Yu; Li, Panyu; Xie, Tonghui; Zhang, Yongkui, E-mail: zhangyongkui@scu.edu.cn

    2016-11-05

    Highlights: • A route to prepare nano α-Fe{sub 2}O{sub 3} red pigment from waste ferrous sulfate is proposed. • Acidithiobacillus ferrooxidans is introduced for accelerating iron oxidation. • The particle size of synthetic α-Fe{sub 2}O{sub 3} is ranged from 22 nm to 86 nm. • The prepared nano α-Fe{sub 2}O{sub 3} red pigment fulfills ISO 1248-2006. - Abstract: Massive ferrous sulfate with excess sulfuric acid is produced in titanium dioxide industry each year, ending up stockpiled or in landfills as solid waste, which is hazardous to environment and in urgent demand to be recycled. In this study, waste ferrous sulfate was used as a second raw material to synthesize nano α-Fe{sub 2}O{sub 3} red pigment powders with a bacteria-assisted oxidation process by Acidithiobacillus ferrooxidans. The synthesis route, mainly consisting of bio-oxidation, precipitation and calcination, was investigated by means of titration, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF) to obtain optimum conditions. Under the optimum conditions, nano α-Fe{sub 2}O{sub 3} red pigment powders contained 98.24 wt.% of Fe{sub 2}O{sub 3} were successfully prepared, with a morphology of spheroidal and particle size ranged from 22 nm to 86 nm and averaged at 45 nm. Moreover, the resulting product fulfilled ISO 1248-2006, the standards of iron oxide pigments.

  4. Neuron-glia metabolic coupling and plasticity.

    Science.gov (United States)

    Magistretti, Pierre J

    2011-04-01

    The focus of the current research projects in my laboratory revolves around the question of metabolic plasticity of neuron-glia coupling. Our hypothesis is that behavioural conditions, such as for example learning or the sleep-wake cycle, in which synaptic plasticity is well documented, or during specific pathological conditions, are accompanied by changes in the regulation of energy metabolism of astrocytes. We have indeed observed that the 'metabolic profile' of astrocytes is modified during the sleep-wake cycle and during conditions mimicking neuroinflammation in the presence or absence of amyloid-β. The effect of amyloid-β on energy metabolism is dependent on its state of aggregation and on internalization of the peptide by astrocytes. Distinct patterns of metabolic activity could be observed during the learning and recall phases in a spatial learning task. Gene expression analysis in activated areas, notably hippocampous and retrosplenial cortex, demonstrated that the expression levels of several genes implicated in astrocyte-neuron metabolic coupling are enhanced by learning. Regarding metabolic plasticity during the sleep-wake cycle, we have observed that the level of expression of a panel of selected genes, which we know are key for neuron-glia metabolic coupling, is modulated by sleep deprivation.

  5. Peroxisomes, lipid metabolism, and peroxisomal disorders

    NARCIS (Netherlands)

    Wanders, R. J. A.

    2004-01-01

    Peroxisomes catalyse a large variety of different cellular functions of which most have to do with lipid metabolism. This paper deals with the role of peroxisomes in three key pathways of lipid metabolism, including: (1) etherphospholipid biosynthesis, (2) fatty acid beta-oxidation, and (3) fatty

  6. 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...

  7. 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,

  8. The prevalence of metabolic syndrome components, individually ...

    African Journals Online (AJOL)

    2013-03-19

    Mar 19, 2013 ... 2005; 112: e297 and Circulation. 2005; 112: e298). Circulation. 2005; 112: 2735Б52. 19. Al-Lawati JA, Mohammed AJ, Al-Hinai HQ, Jousilahti P. Prevalence of the metabolic syndrome among Omani adults. Diabetes Care. 2003; 26: 1781Б5. 20. Al-Qahtani DA, Imtiaz ML. Prevalence of metabolic syndrome.

  9. Investigation of metabolic encephalopathy | van der Watt ...

    African Journals Online (AJOL)

    Encephalopathy may be a presenting sign in a wide range of medical conditions. This review focuses only on the diagnosis and initial management of those inherited metabolic diseases (IMDs) prevalent in South Africa that may present with encephalopathy in childhood. Metabolic encephalopathy is a medical emergency, ...

  10. Peroxisomes, lipid metabolism, and human disease

    NARCIS (Netherlands)

    Wanders, R. J.

    2000-01-01

    In the past few years, much has been learned about the metabolic functions of peroxisomes. These studies have shown that peroxisomes play a major role in lipid metabolism, including fatty acid beta-oxidation, etherphospholipid biosynthesis, and phytanic acid alpha-oxidation. This article describes

  11. 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 ...

  12. 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

  13. An Advance Organizer for Teaching Bacterial Metabolism

    Science.gov (United States)

    Barbosa, Heloiza R.; Marques, Marilis V.; Torres, Bayardo B.

    2005-01-01

    The metabolic versatility of bacteria is a source of learning difficulty for students in classical microbiology courses. To facilitate the learning process, the authors developed an advance organizer. It consists of a set of six diagrams of metabolic pathways describing the basic living requirements of several types of bacteria: energy, carbon…

  14. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob

    2016-01-01

    The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance im...

  15. Targeting Cancer Metabolism: Dietary and Pharmacologic Interventions.

    Science.gov (United States)

    Vernieri, Claudio; Casola, Stefano; Foiani, Marco; Pietrantonio, Filippo; de Braud, Filippo; Longo, Valter

    2016-12-01

    Most tumors display oncogene-driven reprogramming of several metabolic pathways, which are crucial to sustain their growth and proliferation. In recent years, both dietary and pharmacologic approaches that target deregulated tumor metabolism are beginning to be considered for clinical applications. Dietary interventions exploit the ability of nutrient-restricted conditions to exert broad biological effects, protecting normal cells, organs, and systems, while sensitizing a wide variety of cancer cells to cytotoxic therapies. On the other hand, drugs targeting enzymes or metabolites of crucial metabolic pathways can be highly specific and effective, but must be matched with a responsive tumor, which might rapidly adapt. In this review, we illustrate how dietary and pharmacologic therapies differ in their effect on tumor growth, proliferation, and metabolism and discuss the available preclinical and clinical evidence in favor of or against each of them. We also indicate, when appropriate, how to optimize future investigations on metabolic therapies on the basis of tumor- and patient-related characteristics. To our knowledge, this is the first review article that comprehensively analyzes the preclinical and preliminary clinical experimental foundations of both dietary and pharmacologic metabolic interventions in cancer therapy. Among several promising therapies, we propose treatment personalization on the basis of tumor genetics, tumor metabolism, and patient systemic metabolism.Cancer Discov; 6(12); 1315-33. ©2016 AACR. ©2016 American Association for Cancer Research.

  16. 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

  17. Preoperative metabolic acidosis in infants with gastroschisis.

    Science.gov (United States)

    El-Naggar, W; Almudeer, A; Vincer, M; Yanchar, N L

    2017-01-01

    There is little in literature regarding preoperative management of infants with gastroschisis. It is unclear if these infants develop metabolic acidosis as a consequence of prolonged intrauterine gut compromise or dehydration secondary to increased fluid loss. To assess the frequency of preoperative metabolic acidosis in infants with gastroschisis and investigate whether this acidosis reflects degree of gut compromise. All infants with gastroschisis born between May 2005 and April 2013 in a single tertiary care center were reviewed. Metabolic acidosis was defined by the presence of pH preoperative metabolic acidosis and its association with gastroschisis prognostic score (GPS), time to first and time to reach full feeds were investigated. Sixty infants were identified, 11 were excluded (birth depression/lack of preoperative blood gases). Median preoperative total fluid intake was 130 ml/kg/d. Nine infants (18%) had metabolic acidosis at a median age of 1.2 hours. No association was found between metabolic acidosis or serum lactate and GPS, age at first feed or age at full feeds. Preoperative metabolic acidosis was identified in a significant number of patients with gastroschisis despite high fluid intake. It does not appear to be associated with the degree of gut compromise. Using metabolic acidosis as an indication of dehydration in these patients needs more investigation.

  18. Forearm metabolism during infusion of adrenaline

    DEFF Research Database (Denmark)

    Simonsen, L; Stefl, B; Bülow, J

    2000-01-01

    Human skeletal muscle metabolism is often investigated by measurements of substrate fluxes across the forearm. To evaluate whether the two forearms give the same metabolic information, nine healthy subjects were studied in the fasted state and during infusion of adrenaline. Both arms were cathete...

  19. Progress in Metabolic Engineering of Saccharomyces cerevisiae

    OpenAIRE

    Nevoigt, Elke

    2008-01-01

    Summary: The traditional use of the yeast Saccharomyces cerevisiae in alcoholic fermentation has, over time, resulted in substantial accumulated knowledge concerning genetics, physiology, and biochemistry as well as genetic engineering and fermentation technologies. S. cerevisiae has become a platform organism for developing metabolic engineering strategies, methods, and tools. The current review discusses the relevance of several engineering strategies, such as rational and inverse metabolic...

  20. The metabolic syndrome - background and treatment

    OpenAIRE

    van Zwieten, P.A.

    2006-01-01

    The metabolic syndrome (MBS) is characterised by a clustering of cardiovascular and metabolic risk factors. This syndrome is now widely recognised as a distinct pathological entity, and it is receiving a great deal of attention in the medical literature but also in the lay press.

  1. The metabolic syndrome in cancer survivors

    NARCIS (Netherlands)

    de Haas, Esther C.; Oosting, Sjoukje F.; Lefrandt, Joop D.; Wolffenbuttel, Bruce H. R.; Sleijfer, Dirk Th; Gietema, Jourik A.

    The metabolic syndrome, as a cluster of cardiovascular risk factors, may represent an important connection between cancer treatment and its common late effect of cardiovascular disease. Insight into the aetiology of the metabolic syndrome after cancer treatment might help to identify and treat

  2. Fifteen years experience: Egyptian metabolic lab

    African Journals Online (AJOL)

    Ekram M. Fateen

    2014-08-20

    Aug 20, 2014 ... Abstract Background: Inborn errors of metabolism (IEM) are single gene disorders responsible for abnormalities in ... of inherited metabolic disorders in Egypt was very limited and diagnosed mainly on clinical suspi- cion. In 1995 ..... tomatic in newborns, but if left untreated it affects liver, kid- ney, bone, and ...

  3. 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

  4. Central nervous system control of triglyceride metabolism

    NARCIS (Netherlands)

    Geerling, Johanna Janetta (Janine)

    2013-01-01

    This thesis describes the role of the brain in the regulation of peripheral triglyceride metabolism, in the context of the metabolic syndrome. Based on various pharmacological studies we described the role of two hormones, insulin and glucagon-like peptide-1, in the production and clearance of

  5. Aspects of plasma triglyceride metabolism in children

    NARCIS (Netherlands)

    P.P. Forget

    1975-01-01

    textabstractThis thesis aimed at investigating some aspects of plasma triglyceride metabolism in children. In the introduction general aspects of plasma triglyceride metabolism are presented. Chapter 1 reviews recent litterature data on the intravenous fat tolerance test and on plasma postheparin

  6. Investigating the Copper Isotope Composition of Red Mountain Creek: a Stream Affected by Acid Mine Drainage

    Science.gov (United States)

    Kimball, B. E.; Mathur, R.; Brantley, S. L.; Vervoort, J. D.

    2005-12-01

    Understanding the sources of metals and the processes that affect their transport in watersheds affected by acid mine drainage (AMD) is central to improving stream water quality. Using a new technique to address an old problem, we measured the 65Cu/63Cu ratios in filtered (pore size = 0.45μm or 0.22μm) and unfiltered samples of AMD-impacted streamwater collected during low-flow conditions from Red Mountain Creek near Silverton, Colorado. Red Mountain Creek is a small mountain stream receiving metal-rich, acidic drainage from acid-sulfate and quartz-sericite-pyrite alteration zones within dacitic-andesitic lavas and volcaniclastic sediments. We measured δ65Cu values [where δ65Cu = ((65Cu/63Cusample/65Cu/63Custandard) - 1) × 103] on a multi-collector inductively coupled plasma mass spectrometer; instrumental mass bias was corrected by doping with the Johnson-Mattey Zn solution and bracketing with the NIST976 standard. All samples are enriched in 65Cu, with δ65Cu values ranging from 1.03 ± 0.10‰ to 3.76 ± 0.10‰ (2σ). Higher values correspond to an inflow emanating from a mineshaft that shows the highest Cu concentration (10.4 mg/L). As Cu becomes less concentrated downstream, the δ65Cu values generally decrease. At two of the three sample locations, the filtered samples are more enriched in 65Cu than the unfiltered samples, which contain suspended precipitates. These results are consistent with previous batch-leach experiments showing that during dissolution of chalcopyrite (CuFeS2) and chalcocite (Cu2S) (with and without Acidithiobacillus ferrooxidans), Cu released into solution by leaching was enriched in 65Cu and Cu precipitates were depleted relative to the starting sulfide minerals. This fractionation may indicate that biotic (e.g., microbial metabolism) and/or abiotic processes (e.g., metal sorption and mineral precipitation) induce isotope effects during Cu partitioning. Future measurements of 65Cu/63Cu ratios in primary Cu-sulfide minerals and

  7. Metabolically healthy obesity and ischemic heart disease

    DEFF Research Database (Denmark)

    Hansen, Louise; Netterstrøm, Marie K.; Johansen, Nanna B

    2017-01-01

    Context: Recent studies have suggested that a subgroup of obese individuals is not at increased risk of obesity-related complications. This subgroup has been referred to as metabolically healthy obese. Objective: To investigate whether obesity is a risk factor for development of ischemic heart...... Measures: IHD. Results: During follow-up, 323 participants developed IHD. Metabolically healthy obese men had increased risk of IHD compared with metabolically healthy normal-weight men [hazard ratio (HR), 3.1; 95% confidence interval (CI), 1.1 to 8.2)]. The corresponding results for women were less...... healthy individuals became metabolically unhealthy after 5 years of follow-up. When these changes in exposure status were taken into account, slightly higher risk estimates were found. Conclusions: Being obese is associated with higher incidence of IHD irrespective of metabolic status, and we question...

  8. Nuclear magnetic resonance and plant metabolic engineering.

    Science.gov (United States)

    Shachar-Hill, Yair

    2002-01-01

    Nuclear magnetic resonance (NMR) can be used to measure metabolite levels and metabolic fluxes, to probe the intracellular environment, and to follow transport and energetics nondestructively. NMR methods are therefore powerful aids to understanding plant metabolism and physiology. Both spectroscopy and imaging can help overcome the unique challenges that plants present to the metabolic engineer by detecting, identifying, quantifying, and localizing novel metabolites in vivo and in extracts; revealing the composition and physical state of cell wall and other polymers; allowing the identification of active pathways; providing quantitative measures of metabolic flux; and testing hypotheses about the effects of engineered traits on plant physiological function. The aim of this review is to highlight recent studies in which NMR has contributed to metabolic engineering of plants and to illustrate the unique characteristics of NMR measurements that give it the potential to make greater contributions in the future.

  9. VISCOSITY DICTATES METABOLIC ACTIVITY of Vibrio ruber

    Directory of Open Access Journals (Sweden)

    Maja eBoric

    2012-07-01

    Full Text Available Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment.

  10. Temporal Control of Metabolic Amplitude by Nocturnin

    Directory of Open Access Journals (Sweden)

    Jeremy J. Stubblefield

    2018-01-01

    Full Text Available The timing of food intake and nutrient utilization is critical to health and regulated partly by the circadian clock. Increased amplitude of circadian oscillations and metabolic output has been found to improve health in diabetic and obesity mouse models. Here, we report a function for the circadian deadenylase Nocturnin as a regulator of metabolic amplitude across the day/night cycle and in response to nutrient challenge. We show that mice lacking Nocturnin (Noct−/− display significantly increased amplitudes of mRNA expression of hepatic genes encoding key metabolic enzymes regulating lipid and cholesterol synthesis, both over the daily circadian cycle and in response to fasting and refeeding. Noct−/− mice have increased plasma triglyceride throughout the night and increased amplitude of hepatic cholesterol levels. Therefore, posttranscriptional control by Nocturnin regulates the amplitude of these critical metabolic pathways, and loss of this activity results in increased metabolic flux and reduced obesity.

  11. Viscosity dictates metabolic activity of Vibrio ruber

    Science.gov (United States)

    Borić, Maja; Danevčič, Tjaša; Stopar, David

    2012-01-01

    Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase (GPD) increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment. PMID:22826705

  12. One-carbon metabolism in cancer.

    Science.gov (United States)

    Newman, Alice C; Maddocks, Oliver D K

    2017-06-06

    Cells require one-carbon units for nucleotide synthesis, methylation and reductive metabolism, and these pathways support the high proliferative rate of cancer cells. As such, anti-folates, drugs that target one-carbon metabolism, have long been used in the treatment of cancer. Amino acids, such as serine are a major one-carbon source, and cancer cells are particularly susceptible to deprivation of one-carbon units by serine restriction or inhibition of de novo serine synthesis. Recent work has also begun to decipher the specific pathways and sub-cellular compartments that are important for one-carbon metabolism in cancer cells. In this review we summarise the historical understanding of one-carbon metabolism in cancer, describe the recent findings regarding the generation and usage of one-carbon units and explore possible future therapeutics that could exploit the dependency of cancer cells on one-carbon metabolism.

  13. Scaling up the curvature of mammalian metabolism

    Directory of Open Access Journals (Sweden)

    Juan eBueno

    2014-10-01

    Full Text Available A curvilinear relationship between mammalian metabolic rate and body size on a log-log scale has been adopted in lieu of thelongstanding concept of a 3/4 allometric relationship (Kolokotrones et al. 2010. The central tenet of Metabolic Ecology (ME states that metabolism at the individual level scales-up to drive the ecology of populations, communities and ecosystems. If this tenet is correct, the curvature of metabolism should be perceived in other ecological traits. By analyzing the size scaling allometry of eight different mammalian traits including basal and field metabolic rate, offspring biomass production, ingestion rate, costs of locomotion, life span, population growth rate and population density we show that the curvature affects most ecological rates and

  14. Energy metabolism and thermoregulation in old age

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, G. A.

    1979-01-01

    Over their life spans, mice and men alike show a 15 to 30% decrease in their minimum, or resting, levels of energy metabolism, and a 50 to 70% decrease in the metabolism of activity. This, together with age-decrements in the capacity to regulate heat loss, makes the old person more susceptible to hypothermia that the young. Two independent relations of length of life to metabolic rate have been found in mice. First, as average metabolic rate increases, survival time decreases, and second, as the fraction of metabolic energy available for activity increases, survival time increases. The second term is the important one, for it is the first experimental support for the efforts to maintain human health and vigor, and to extend life, by means of regimes of exercise and activity. If mice are good models for men in these respects, rapid progress in understanding is possible.

  15. Metabolic Modulation in Macrophage Effector Function

    Directory of Open Access Journals (Sweden)

    Ciana Diskin

    2018-02-01

    Full Text Available Traditionally cellular respiration or metabolism has been viewed as catabolic and anabolic pathways generating energy and biosynthetic precursors required for growth and general cellular maintenance. However, growing literature provides evidence of a much broader role for metabolic reactions and processes in controlling immunological effector functions. Much of this research into immunometabolism has focused on macrophages, cells that are central in pro- as well as anti-inflammatory responses—responses that in turn are a direct result of metabolic reprogramming. As we learn more about the precise role of metabolic pathways and pathway intermediates in immune function, a novel opportunity to target immunometabolism therapeutically has emerged. Here, we review the current understanding of the regulation of macrophage function through metabolic remodeling.

  16. Systems metabolic engineering for chemicals and materials.

    Science.gov (United States)

    Lee, Jeong Wook; Kim, Tae Yong; Jang, Yu-Sin; Choi, Sol; Lee, Sang Yup

    2011-08-01

    Metabolic engineering has contributed significantly to the enhanced production of various value-added and commodity chemicals and materials from renewable resources in the past two decades. Recently, metabolic engineering has been upgraded to the systems level (thus, systems metabolic engineering) by the integrated use of global technologies of systems biology, fine design capabilities of synthetic biology, and rational-random mutagenesis through evolutionary engineering. By systems metabolic engineering, production of natural and unnatural chemicals and materials can be better optimized in a multiplexed way on a genome scale, with reduced time and effort. Here, we review the recent trends in systems metabolic engineering for the production of chemicals and materials by presenting general strategies and showcasing representative examples. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Querying metabolism under different physiological constraints.

    Science.gov (United States)

    Cakmak, Ali; Ozsoyoglu, Gultekin; Hanson, Richard W

    2010-04-01

    Metabolism is a representation of the biochemical principles that govern the production, consumption, degradation, and biosynthesis of metabolites in living cells. Organisms respond to changes in their physiological conditions or environmental perturbations (i.e. constraints) via cooperative implementation of such principles. Querying inner working principles of metabolism under different constraints provides invaluable insights for both researchers and educators. In this paper, we propose a metabolism query language (MQL) and discuss its query processing. MQL enables researchers to explore the behavior of the metabolism with a wide-range of predicates including dietary and physiological condition specifications. The query results of MQL are enriched with both textual and visual representations, and its query processing is completely tailored based on the underlying metabolic principles.

  18. Psychosocial risk factors for the metabolic syndrome

    DEFF Research Database (Denmark)

    Pedersen, Jolene Masters; Lund, Rikke; Andersen, Ingelise

    2016-01-01

    Background/Objectives: Metabolic deregulations and development of metabolic syndrome may be an important pathway underlying the relationship between stress and cardiovascular disease. We aim to estimate the effect of a comprehensive range of psychosocial factors on the risk of developing metabolic...... syndrome in men and women. Methods: The study population consisted of 3621 men and women from the Copenhagen City Heart Study who were free of metabolic syndrome at baseline and reexamined after 10 years. The data was analyzed by multivariable logistic regression models adjusted for age, education, income.......11) to be risk factors for developing the metabolic syndrome in women, while vital exhaustion (OR 2.09, 95% CI 0.95 to 4.59) and intake of sleep medications (OR 2.54, 95% CI 0.92 to 5.96) may play a more important role in men. Conclusions: Experiencing major life events in work and adult life and...

  19. Metabolic syndrome in fixed-shift workers.

    Science.gov (United States)

    Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

    2015-01-01

    OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status), socioeconomic (educational level, income and work shift), and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration) of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2). The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2), followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64), workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93) and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24). On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73). CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  20. Metabolic syndrome in fixed-shift workers

    Directory of Open Access Journals (Sweden)

    Raquel Canuto

    2015-01-01

    Full Text Available OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status, socioeconomic (educational level, income and work shift, and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2. The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2, followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64, workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93 and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24. On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73. CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

  1. Virocell Metabolism: Metabolic Innovations During Host-Virus Interactions in the Ocean.

    Science.gov (United States)

    Rosenwasser, Shilo; Ziv, Carmit; Creveld, Shiri Graff van; Vardi, Assaf

    2016-10-01

    Marine viruses are considered to be major ecological, evolutionary, and biogeochemical drivers of the marine environment, responsible for nutrient recycling and determining species composition. Viruses can re-shape their host's metabolic network during infection, generating the virocell-a unique metabolic state that supports their specific requirement. Here we discuss the concept of 'virocell metabolism' and its formation by rewiring of host-encoded metabolic networks, or by introducing virus-encoded auxiliary metabolic genes which provide the virocell with novel metabolic capabilities. The ecological role of marine viruses is commonly assessed by their relative abundance and phylogenetic diversity, lacking the ability to assess the dynamics of active viral infection. The new ability to define a unique metabolic state of the virocell will expand the current virion-centric approaches in order to quantify the impact of marine viruses on microbial food webs. Copyright © 2016. Published by Elsevier Ltd.

  2. Thermodynamic principles governing metabolic operation : inference, analysis, and prediction

    NARCIS (Netherlands)

    Niebel, Bastian

    2015-01-01

    The principles governing metabolic flux are poorly understood. Because diverse organisms show similar metabolic flux patterns, we hypothesized that fundamental thermodynamic constraints might shape cellular metabolism. We developed a constraint-based model for Saccharomyces cerevisiae that included

  3. Role of the microbiome in energy regulation and metabolism

    NARCIS (Netherlands)

    Nieuwdorp, Max; Gilijamse, Pim W.; Pai, Nikhil; Kaplan, Lee M.

    2014-01-01

    Intestinal microbes regulate metabolic function and energy balance; an altered microbial ecology is believed to contribute to the development of several metabolic diseases. Relative species abundance and metabolic characteristics of the intestinal microbiota change substantially in those who are

  4. The effect of mitochondrial dysfunction on cytosolic nucleotide metabolism

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Lykke, Anne; Rasmussen, Lene Juel

    2010-01-01

    Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels...

  5. A metabolic prosurvival role for PML in breast cancer

    NARCIS (Netherlands)

    Carracedo, Arkaitz; Weiss, Dror; Leliaert, Amy K.; Bhasin, Manoj; de Boer, Vincent C. J.; Laurent, Gaelle; Adams, Andrew C.; Sundvall, Maria; Song, Su Jung; Ito, Keisuke; Finley, Lydia S.; Egia, Ainara; Libermann, Towia; Gerhart-Hines, Zachary; Puigserver, Pere; Haigis, Marcia C.; Maratos-Flier, Elefteria; Richardson, Andrea L.; Schafer, Zachary T.; Pandolfi, Pier P.

    2012-01-01

    Cancer cells exhibit an aberrant metabolism that facilitates more efficient production of biomass and hence tumor growth and progression. However, the genetic cues modulating this metabolic switch remain largely undetermined. We identified a metabolic function for the promyelocytic leukemia (PML)

  6. Body composition and basal metabolic rate in Hidradenitis Suppurativa

    DEFF Research Database (Denmark)

    Miller, I M; Rytgaard, Helene Charlotte; Mogensen, U B

    2016-01-01

    composition (e.g. abdominal fat) may be more so. Basal metabolic rate (BMR) is an expression of resting metabolism and may serve as a complementary tool when assessing the possibly underlying metabolism behind a persons' body composition. OBJECTIVE: To investigate the body composition and basal metabolic rate.......70-105.56) (P basal metabolic rate (BMR) in HS patients may reflect...... a dysfunctional metabolism contributing to the high-fat-body composition....

  7. The MRSD web server for metabolic route search and design

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: yong cao, Deguo Xia & Haoran Zheng ### Abstract The Metabolic Route Search and Design (MRSD) server is an integrated platform for metabolic route search (MRS) and metabolic route design (MRD) based on the data from KEGG. MRS computes metabolic routes between the source metabolite and the product metabolite on the weighted compound transforming graph. Each graph represents a metabolic network. The output from a typical server run contains graphic illustrating metabolic routes ...

  8. Modeling cancer metabolism on a genome scale

    Science.gov (United States)

    Yizhak, Keren; Chaneton, Barbara; Gottlieb, Eyal; Ruppin, Eytan

    2015-01-01

    Cancer cells have fundamentally altered cellular metabolism that is associated with their tumorigenicity and malignancy. In addition to the widely studied Warburg effect, several new key metabolic alterations in cancer have been established over the last decade, leading to the recognition that altered tumor metabolism is one of the hallmarks of cancer. Deciphering the full scope and functional implications of the dysregulated metabolism in cancer requires both the advancement of a variety of omics measurements and the advancement of computational approaches for the analysis and contextualization of the accumulated data. Encouragingly, while the metabolic network is highly interconnected and complex, it is at the same time probably the best characterized cellular network. Following, this review discusses the challenges that genome-scale modeling of cancer metabolism has been facing. We survey several recent studies demonstrating the first strides that have been done, testifying to the value of this approach in portraying a network-level view of the cancer metabolism and in identifying novel drug targets and biomarkers. Finally, we outline a few new steps that may further advance this field. PMID:26130389

  9. Molecular interactions between NAFLD and xenobiotic metabolism

    Directory of Open Access Journals (Sweden)

    Adviti eNaik

    2013-01-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD, the hepatic manifestation of the metabolic syndrome, is a complex multifactorial disease characterised by metabolic deregulations that include accumulation of lipids in the liver, lipotoxicity and insulin resistance. The progression of NAFLD to NASH and cirrhosis, and ultimately to carcinomas, is governed by interplay of pro-inflammatory pathways, oxidative stress, as well as fibrogenic and apoptotic cues. As the liver is the major organ of biotransformation, deregulations in hepatic signalling pathways have effects on both, xenobiotic and endobiotic metabolism. Several major nuclear receptors involved in the transcription and regulation of phase I and II drug metabolizing enzymes and transporters also have endobiotic ligands including several lipids. Hence, hepatic lipid accumulation in steatosis and NAFLD, which leads to deregulated activation patterns of nuclear receptors, may result in altered drug metabolism capacity in NAFLD patients. On the other hand, genetic and association studies have indicated that a malfunction in drug metabolism can affect the prevalence and severity of NAFLD. This review focuses on the complex interplay between NAFLD pathogenesis and drug metabolism. A better understanding of these relationships is a prerequisite for developing improved drug dosing algorithms for the pharmacotherapy of patients with different stages of NAFLD.

  10. The Metabolic Phenotype of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Eric Eidelman

    2017-06-01

    Full Text Available Prostate cancer is the most common non-cutaneous cancer in men in the United States. Cancer metabolism has emerged as a contemporary topic of great interest for improved mechanistic understanding of tumorigenesis. Prostate cancer is a disease model of great interest from a metabolic perspective. Prostatic tissue exhibits unique metabolic activity under baseline conditions. Benign prostate cells accumulate zinc, and this excess zinc inhibits citrate oxidation and metabolism within the citric acid cycle, effectively resulting in citrate production. Malignant cells, however, actively oxidize citrate and resume more typical citric acid cycle function. Of further interest, prostate cancer does not exhibit the Warburg effect, an increase in glucose uptake, seen in many other cancers. These cellular metabolic differences and others are of clinical interest as they present a variety of potential therapeutic targets. Furthermore, understanding of the metabolic profile differences between benign prostate versus low- and high-grade prostate cancers also represents an avenue to better understand cancer progression and potentially develop new diagnostic testing. In this paper, we review the current state of knowledge on the metabolic phenotypes of prostate cancer.

  11. Metabolic shifts during aging and pathology.

    Science.gov (United States)

    Ma, Yina; Li, Ji

    2015-04-01

    The heart is a very special organ in the body and has a high requirement for metabolism due to its constant workload. As a consequence, to provide a consistent and sufficient energy a high steady-state demand of metabolism is required by the heart. When delicately balanced mechanisms are changed by physiological or pathophysiological conditions, the whole system's homeostasis will be altered to a new balance, which contributes to the pathologic process. So it is no wonder that almost every heart disease is related to metabolic shift. Furthermore, aging is also found to be related to the reduction in mitochondrial function, insulin resistance, and dysregulated intracellular lipid metabolism. Adenosine monophosphate-activated protein kinase (AMPK) functions as an energy sensor to detect intracellular ATP/AMP ratio and plays a pivotal role in intracellular adaptation to energy stress. During different pathology (like myocardial ischemia and hypertension), the activation of cardiac AMPK appears to be essential for repairing cardiomyocyte's function by accelerating ATP generation, attenuating ATP depletion, and protecting the myocardium against cardiac dysfunction and apoptosis. In this overview, we will talk about the normal heart's metabolism, how metabolic shifts during aging and different pathologies, and how AMPK regulates metabolic changes during these conditions. © 2015 American Physiological Society.

  12. Principles for circadian orchestration of metabolic pathways

    Science.gov (United States)

    Thurley, Kevin; Herbst, Christopher; Wesener, Felix; Koller, Barbara; Wallach, Thomas; Maier, Bert; Kramer, Achim

    2017-01-01

    Circadian rhythms govern multiple aspects of animal metabolism. Transcriptome-, proteome- and metabolome-wide measurements have revealed widespread circadian rhythms in metabolism governed by a cellular genetic oscillator, the circadian core clock. However, it remains unclear if and under which conditions transcriptional rhythms cause rhythms in particular metabolites and metabolic fluxes. Here, we analyzed the circadian orchestration of metabolic pathways by direct measurement of enzyme activities, analysis of transcriptome data, and developing a theoretical method called circadian response analysis. Contrary to a common assumption, we found that pronounced rhythms in metabolic pathways are often favored by separation rather than alignment in the times of peak activity of key enzymes. This property holds true for a set of metabolic pathway motifs (e.g., linear chains and branching points) and also under the conditions of fast kinetics typical for metabolic reactions. By circadian response analysis of pathway motifs, we determined exact timing separation constraints on rhythmic enzyme activities that allow for substantial rhythms in pathway flux and metabolite concentrations. Direct measurements of circadian enzyme activities in mouse skeletal muscle confirmed that such timing separation occurs in vivo. PMID:28159888

  13. Computational Functional Analysis of Lipid Metabolic Enzymes.

    Science.gov (United States)

    Bagnato, Carolina; Have, Arjen Ten; Prados, María B; Beligni, María V

    2017-01-01

    The computational analysis of enzymes that participate in lipid metabolism has both common and unique challenges when compared to the whole protein universe. Some of the hurdles that interfere with the functional annotation of lipid metabolic enzymes that are common to other pathways include the definition of proper starting datasets, the construction of reliable multiple sequence alignments, the definition of appropriate evolutionary models, and the reconstruction of phylogenetic trees with high statistical support, particularly for large datasets. Most enzymes that take part in lipid metabolism belong to complex superfamilies with many members that are not involved in lipid metabolism. In addition, some enzymes that do not have sequence similarity catalyze similar or even identical reactions. Some of the challenges that, albeit not unique, are more specific to lipid metabolism refer to the high compartmentalization of the routes, the catalysis in hydrophobic environments and, related to this, the function near or in biological membranes.In this work, we provide guidelines intended to assist in the proper functional annotation of lipid metabolic enzymes, based on previous experiences related to the phospholipase D superfamily and the annotation of the triglyceride synthesis pathway in algae. We describe a pipeline that starts with the definition of an initial set of sequences to be used in similarity-based searches and ends in the reconstruction of phylogenies. We also mention the main issues that have to be taken into consideration when using tools to analyze subcellular localization, hydrophobicity patterns, or presence of transmembrane domains in lipid metabolic enzymes.

  14. A diagnostic algorithm for metabolic myopathies.

    Science.gov (United States)

    Berardo, Andres; DiMauro, Salvatore; Hirano, Michio

    2010-03-01

    Metabolic myopathies comprise a clinically and etiologically diverse group of disorders caused by defects in cellular energy metabolism, including the breakdown of carbohydrates and fatty acids to generate adenosine triphosphate, predominantly through mitochondrial oxidative phosphorylation. Accordingly, the three main categories of metabolic myopathies are glycogen storage diseases, fatty acid oxidation defects, and mitochondrial disorders due to respiratory chain impairment. The wide clinical spectrum of metabolic myopathies ranges from severe infantile-onset multisystemic diseases to adult-onset isolated myopathies with exertional cramps. Diagnosing these diverse disorders often is challenging because clinical features such as recurrent myoglobinuria and exercise intolerance are common to all three types of metabolic myopathy. Nevertheless, distinct clinical manifestations are important to recognize as they can guide diagnostic testing and lead to the correct diagnosis. This article briefly reviews general clinical aspects of metabolic myopathies and highlights approaches to diagnosing the relatively more frequent subtypes (Fig. 1). Fig. 1 Clinical algorithm for patients with exercise intolerance in whom a metabolic myopathy is suspected. CK-creatine kinase; COX-cytochrome c oxidase; CPT-carnitine palmitoyl transferase; cyt b-cytochrome b; mtDNA-mitochondrial DNA; nDNA-nuclear DNA; PFK-phosphofructokinase; PGAM-phosphoglycerate mutase; PGK-phosphoglycerate kinase; PPL-myophosphorylase; RRF-ragged red fibers; TFP-trifunctional protein deficiency; VLCAD-very long-chain acyl-coenzyme A dehydrogenase.

  15. Optimal flux patterns in cellular metabolic networks

    Energy Technology Data Exchange (ETDEWEB)

    Almaas, E

    2007-01-20

    The availability of whole-cell level metabolic networks of high quality has made it possible to develop a predictive understanding of bacterial metabolism. Using the optimization framework of flux balance analysis, I investigate metabolic response and activity patterns to variations in the availability of nutrient and chemical factors such as oxygen and ammonia by simulating 30,000 random cellular environments. The distribution of reaction fluxes is heavy-tailed for the bacteria H. pylori and E. coli, and the eukaryote S. cerevisiae. While the majority of flux balance investigations have relied on implementations of the simplex method, it is necessary to use interior-point optimization algorithms to adequately characterize the full range of activity patterns on metabolic networks. The interior-point activity pattern is bimodal for E. coli and S. cerevisiae, suggesting that most metabolic reaction are either in frequent use or are rarely active. The trimodal activity pattern of H. pylori indicates that a group of its metabolic reactions (20%) are active in approximately half of the simulated environments. Constructing the high-flux backbone of the network for every environment, there is a clear trend that the more frequently a reaction is active, the more likely it is a part of the backbone. Finally, I briefly discuss the predicted activity patterns of the central-carbon metabolic pathways for the sample of random environments.

  16. Modeling cancer metabolism on a genome scale.

    Science.gov (United States)

    Yizhak, Keren; Chaneton, Barbara; Gottlieb, Eyal; Ruppin, Eytan

    2015-06-30

    Cancer cells have fundamentally altered cellular metabolism that is associated with their tumorigenicity and malignancy. In addition to the widely studied Warburg effect, several new key metabolic alterations in cancer have been established over the last decade, leading to the recognition that altered tumor metabolism is one of the hallmarks of cancer. Deciphering the full scope and functional implications of the dysregulated metabolism in cancer requires both the advancement of a variety of omics measurements and the advancement of computational approaches for the analysis and contextualization of the accumulated data. Encouragingly, while the metabolic network is highly interconnected and complex, it is at the same time probably the best characterized cellular network. Following, this review discusses the challenges that genome-scale modeling of cancer metabolism has been facing. We survey several recent studies demonstrating the first strides that have been done, testifying to the value of this approach in portraying a network-level view of the cancer metabolism and in identifying novel drug targets and biomarkers. Finally, we outline a few new steps that may further advance this field. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  17. Metabolism and virulence in Neisseria meningitidis

    Directory of Open Access Journals (Sweden)

    Christoph eSchoen

    2014-08-01

    Full Text Available A longstanding question in infection biology addresses the genetic basis for invasive behaviour in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions.

  18. Association between Metabolic Syndrome and Job Rank.

    Science.gov (United States)

    Mehrdad, Ramin; Pouryaghoub, Gholamreza; Moradi, Mahboubeh

    2018-01-01

    The occupation of the people can influence the development of metabolic syndrome. To determine the association between metabolic syndrome and its determinants with the job rank in workers of a large car factory in Iran. 3989 male workers at a large car manufacturing company were invited to participate in this cross-sectional study. Demographic and anthropometric data of the participants, including age, height, weight, and abdominal circumference were measured. Blood samples were taken to measure lipid profile and blood glucose level. Metabolic syndrome was diagnosed in each participant based on ATPIII 2001 criteria. The workers were categorized based on their job rank into 3 groups of (1) office workers, (2) workers with physical exertion, and (3) workers with chemical exposure. The study characteristics, particularly the frequency of metabolic syndrome and its determinants were compared among the study groups. The prevalence of metabolic syndrome in our study was 7.7% (95% CI 6.9 to 8.5). HDL levels were significantly lower in those who had chemical exposure (p=0.045). Diastolic blood pressure was significantly higher in those who had mechanical exertion (p=0.026). The frequency of metabolic syndrome in the office workers, workers with physical exertion, and workers with chemical exposure was 7.3%, 7.9%, and 7.8%, respectively (p=0.836). Seemingly, there is no association between metabolic syndrome and job rank.

  19. Bariatric surgery, lipoprotein metabolism and cardiovascular risk.

    Science.gov (United States)

    Tailleux, Anne; Rouskas, Konstantinos; Pattou, François; Staels, Bart

    2015-08-01

    To summarize recent epidemiological, preclinical and clinical studies on the effects of Roux-en-Y-gastric bypass (RYGBP) surgery on cardiovascular risk factors and the underlying mechanisms. Although RYGBP has mechanical effects on the gastrointestinal tract, the reduced gastric pouch and intestinal calorie absorption cannot fully explain the metabolic improvements. Obesity predisposes to cardiovascular risk factors such as dyslipidemia, type 2 diabetes, nonalcoholic fatty liver disease and hypertension. In contrast to the limited success of pharmacological and lifestyle interventions, RYGBP induces sustained weight loss, metabolic improvements and decreases morbidity/mortality. In line, RYGBP reduces cardiovascular risk factors. Although the mechanisms are not entirely understood, RYGBP induces complex changes in the gut affecting other organs through endocrine and metabolic signals from the intestine to all key metabolic organs, which can link RYGBP and decreased cardiovascular risk. Here, we discuss the roles of changes in lipid absorption and metabolism, bile acid metabolism, gut hormones and the microbiote as potential mechanisms in the decreased cardiovascular risk and metabolic improvement after RYGBP.

  20. Hypothalamic leucine metabolism regulates liver glucose production.

    Science.gov (United States)

    Su, Ya; Lam, Tony K T; He, Wu; Pocai, Alessandro; Bryan, Joseph; Aguilar-Bryan, Lydia; Gutiérrez-Juárez, Roger

    2012-01-01

    Amino acids profoundly affect insulin action and glucose metabolism in mammals. Here, we investigated the role of the mediobasal hypothalamus (MBH), a key center involved in nutrient-dependent metabolic regulation. Specifically, we tested the novel hypothesis that the metabolism of leucine within the MBH couples the central sensing of leucine with the control of glucose production by the liver. We performed either central (MBH) or systemic infusions of leucine in Sprague-Dawley male rats during basal pancreatic insulin clamps in combination with various pharmacological and molecular interventions designed to modulate leucine metabolism in the MBH. We also examined the role of hypothalamic ATP-sensitive K(+) channels (K(ATP) channels) in the effects of leucine. Enhancing the metabolism of leucine acutely in the MBH lowered blood glucose through a biochemical network that was insensitive to rapamycin but strictly dependent on the hypothalamic metabolism of leucine to α-ketoisocaproic acid and, further, insensitive to acetyl- and malonyl-CoA. Functional K(ATP) channels were also required. Importantly, molecular attenuation of this central sensing mechanism in rats conferred susceptibility to developing hyperglycemia. We postulate that the metabolic sensing of leucine in the MBH is a previously unrecognized mechanism for the regulation of hepatic glucose production required to maintain glucose homeostasis.