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Sample records for sulfate-reducing conditions metabolic

  1. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

    Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

  2. Metabolic flexibility of sulfate-reducing bacteria

    NARCIS (Netherlands)

    Plugge, C.M.; Zhang, Weinwen; Scholten, J.C.M.; Stams, A.J.M.

    2011-01-01

    Dissimilatory sulfate-reducing prokaryotes (SRB) are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic

  3. METABOLISM OF SULFATE-REDUCING PROKARYOTES

    NARCIS (Netherlands)

    HANSEN, TA

    1994-01-01

    Dissimilatory sulfate reduction is carried out by a heterogeneous group of bacteria and archaea that occur in environments with temperatures up to 105 degrees C. As a group together they have the capacity to metabolize a wide variety of compounds ranging from hydrogen via typical organic

  4. Potentially direct interspecies electron transfer of methanogenesis for syntrophic metabolism under sulfate reducing conditions with stainless steel.

    Science.gov (United States)

    Li, Yue; Zhang, Yaobin; Yang, Yafei; Quan, Xie; Zhao, Zhiqiang

    2017-06-01

    Direct interspecies electron transfer (DIET) is an alternative to syntrophic metabolism in natural carbon cycle as well as in anaerobic digesters, but its function in anaerobic treatment of sulfate-containing wastewater have not yet to be described. Here, conductive stainless steel was added into anaerobic digesters for treating sulfate-containing wastewater to investigate the potential role of DIET in the response to the sulfate impact. Results showed that adding the conductive stainless steel made the anaerobic digestion less affected by the sulfate reduction than adding insulative plastic material. With adding stainless steel, methane production of the digesters increased by 7.5%-24.6%. Microbial analysis showed that the dissimilatory Fe (III) reducers like Geobacter species were enriched on the surface of the stainless steel. These results implied that the potential DIET of methanogenesis was established associating with stainless steel to outcompete the sulfate reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Anaerobic metabolism of nitroaromatic compounds by sulfate-reducing and methanogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Boopathy, R. [Argonne National Lab., IL (United States); Kulpa, C.F. [Notre Dame Univ., IN (United States). Dept. of Biological Sciences

    1994-06-01

    Ecological observations suggest that sulfate-reducing and methanogenic bacteria might metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment, but this ability had not been demonstrated until recently. Most studies on the microbial metabolism of nitroaromatic compounds used aerobic microorganisms. In most cases no mineralization of nitroaromatics occurs, and only superficial modifications of the structures are reported. However, under anaerobic sulfate-reducing conditions, the nitroaromatic compounds reportedly undergo a series of reductions with the formation of amino compounds. For example, trinitrotoluene under sulfate-reducing conditions is reduced to triaminotoluene by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of ammonia from triaminotoluene is achieved by reductive deamination catalyzed by the enzyme reductive deaminase, with the production of ammonia and toluene. Some sulfate reducers can metabolize toluene to CO{sub 2}. Similar metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. Many methanogenic bacteria can reduce nitroaromatic compounds to amino compounds. In this paper we review the anaerobic metabolic processes of nitroaromatic compounds under sulfate-reducing And methanogenic conditions.

  6. Transformation of carbon tetrachloride under sulfate reducing conditions

    NARCIS (Netherlands)

    de Best, JH; Salminen, E; Doddema, HJ; Janssen, DB; Harder, W

    1997-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 mu M, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  7. Transformation of carbon tetrachloride under sulfate reducing conditions

    NARCIS (Netherlands)

    Best, Jappe H. de; Salminen, E.; Doddema, Hans J.; Janssen, Dick B.; Harder, Wim

    1998-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 µM, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  8. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB; Harder, J.

    1999-01-01

    of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than...

  9. Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

    Energy Technology Data Exchange (ETDEWEB)

    Miletto, M.; Williams, K.H.; N' Guessan, A.L.; Lovley, D.R.

    2011-04-01

    Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to

  10. One-carbon metabolism in acetogenic and sulfate-reducing bacteria

    NARCIS (Netherlands)

    Visser, M.

    2015-01-01

    ABSTRACT

    One-carbon metabolism in acetogenic and sulfate-reducing bacteria

    Life on earth is sustained by the constant cycling of six essential elements: oxygen, hydrogen, nitrogen, sulfur, phosphorous,

  11. Acetate Production from Oil under Sulfate-Reducing Conditions in Bioreactors Injected with Sulfate and Nitrate

    Science.gov (United States)

    Callbeck, Cameron M.; Agrawal, Akhil

    2013-01-01

    Oil production by water injection can cause souring in which sulfate in the injection water is reduced to sulfide by resident sulfate-reducing bacteria (SRB). Sulfate (2 mM) in medium injected at a rate of 1 pore volume per day into upflow bioreactors containing residual heavy oil from the Medicine Hat Glauconitic C field was nearly completely reduced to sulfide, and this was associated with the generation of 3 to 4 mM acetate. Inclusion of 4 mM nitrate inhibited souring for 60 days, after which complete sulfate reduction and associated acetate production were once again observed. Sulfate reduction was permanently inhibited when 100 mM nitrate was injected by the nitrite formed under these conditions. Pulsed injection of 4 or 100 mM nitrate inhibited sulfate reduction temporarily. Sulfate reduction resumed once nitrate injection was stopped and was associated with the production of acetate in all cases. The stoichiometry of acetate formation (3 to 4 mM formed per 2 mM sulfate reduced) is consistent with a mechanism in which oil alkanes and water are metabolized to acetate and hydrogen by fermentative and syntrophic bacteria (K. Zengler et al., Nature 401:266–269, 1999), with the hydrogen being used by SRB to reduce sulfate to sulfide. In support of this model, microbial community analyses by pyrosequencing indicated SRB of the genus Desulfovibrio, which use hydrogen but not acetate as an electron donor for sulfate reduction, to be a major community component. The model explains the high concentrations of acetate that are sometimes found in waters produced from water-injected oil fields. PMID:23770914

  12. Genetics and Molecular Biology of Hydrogen Metabolism in Sulfate-Reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

    2014-12-23

    The degradation of our environment and the depletion of fossil fuels make the exploration of alternative fuels evermore imperative. Among the alternatives is biohydrogen which has high energy content by weight and produces only water when combusted. Considerable effort is being expended to develop photosynthetic systems -- algae, cyanobacteria, and anaerobic phototrophs -- for sustainable H2 production. While promising, this approach also has hurdles such as the harvesting of light in densely pigmented cultures that requires costly constant mixing and large areas for exposure to sunlight. Little attention is given to fermentative H2 generation. Thus understanding the microbial pathways to H2 evolution and metabolic processes competing for electrons is an essential foundation that may expand the variety of fuels that can be generated or provide alternative substrates for fine chemical production. We studied a widely found soil anaerobe of the class Deltaproteobacteria, a sulfate-reducing bacterium to determine the electron pathways used during the oxidation of substrates and the potential for hydrogen production.

  13. The use of magnesium peroxide for the inhibition of sulfate-reducing bacteria under anoxic conditions.

    Science.gov (United States)

    Chang, Yu-Jie; Chang, Yi-Tang; Hung, Chun-Hsiung

    2008-11-01

    Sulfate-reducing bacteria (SRB), which cause microbiologically influenced material corrosion under anoxic conditions, form one of the major groups of microorganisms responsible for the generation of hydrogen sulfide. In this study, which is aimed at reducing the presence of SRB, a novel alternative approach involving the addition of magnesium peroxide (MgO2) compounds involving the use of reagent-grade MgO2 and a commercial product (ORC) was evaluated as a means of inhibiting SRB in laboratory batch columns. Different concentrations of MgO2 were added in the columns when black sulfide sediment had appeared in the columns. The experimental results showed that MgO2 is able to inhibit biogenic sulfide. The number of SRB, the sulfide concentration and the sulfate reducing rate (SRR) were decreased. ORCtrade mark as an additive was able to decrease more effectively the concentration of sulfide in water and the SRB-control effect was maintained over a longer time period when ORCtrade mark was used. The level of oxidation-reduction potential (ORP), which has a linear relationship to the sulfide/sulfate ratio, is a good indicator of SRB activity. As determined by fluorescence in-situ hybridization (FISH), most SRB growth was inhibited under increasing amounts of added MgO2. The concentration of sulfide reflected the abundance of the SRB. Utilization of organic matter greater than the theoretical SRB utilization rate indicated that facultative heterotrophs became dominant after MgO2 was added. The results of this study could supply the useful information for further study on evaluating the solution to biocorrosion problems in practical situations.

  14. Evaluating zinc isotope fractionation under sulfate reducing conditions using a flow-through cell and in situ XAS analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson-Hanes, Julia H.; Shrimpton, Heather K.; Veeramani, Harish; Ptacek, Carol J.; Lanzirotti, Antonio; Newville, Matthew; Blowes, David W. (Glasgow); (UC); (Waterloo)

    2017-04-01

    A flow-through cell experiment was conducted to evaluate Zn isotope fractionation during ZnS precipitation under microbially-mediated sulfate-reducing conditions. Synthetic groundwater containing 0.90 mM Zn was pumped through a cell containing creek sediment that was biostimulated to promote sulfate reducing conditions. Real-time, in situ X-ray absorption spectroscopy (XAS) was applied at the Zn K-edge to collect spectra via a Kapton® window in the front of the cell over the course of the experiment. Aqueous effluent samples were collected and analysed to determine concentrations of anions and cations, and Zn isotope ratios. The flow rate was increased step-wise during the experiment to modify the residence time and produce changes in the extent of sulfate reduction, which in turn controlled the extent of ZnS precipitation. Greater enrichment in the heavier isotope in the aqueous phase relative to the input solution was associated with more extensive Zn removal. A Rayleigh curve was fit to the isotope data, where ε = -0.27 ± 0.06‰ (2σ). Evaluation of Zn isotope fractionation under controlled flow conditions is critical to improve the efficacy of this powerful analytical technique when applied to natural systems or remediation projects in the field.

  15. Distribution, community assembly and metabolic potential of sulfate-reducing microorganisms in marine sediments

    DEFF Research Database (Denmark)

    Jochum, Lara

    2017-01-01

    and strategy for subsisting under sulfate and organic carbon limitation in marine sediments is poorly understood. In this thesis I have studied the distribution, community assembly and metabolic potential of SRM populating in the coastal marine sediments of Aarhus Bay. Firstly, I investigated how SRM...... by decreasing availability of organic matter and sulfate with sediment depth. SRM are a taxonomically and metabolically diverse group and populate both surface and subsurface marine sediments. Large subgroups of environmental SRM are uncultured, particularly in marine subsurface sediments, and their physiology...... communities in marine sediment change across the vertical depth profile of sediment cores by next generation sequencing of a functional marker gene indicative of SRM. The abundance, distribution and identity of SRM at different depths were assessed and the results compared with geochemical data. Thereby, I...

  16. Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions

    KAUST Repository

    Gonzalez-Gil, Graciela

    2012-12-01

    The leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4gCODl reactor -1d -1) and sulfate at different COD/SO 4 2- ratios. During the start-up of such acidogenic systems, an initial leaching of trace elements from the inoculum sludge occurred regardless of trace elements supplementation in the reactor influent. The granular sludge maintained the physical structure despite high Fe leaching. After start-up and nonetheless the acidic conditions, Co, Ni, Cu, Zn, Mo and Se were retained or accumulated by the sludge when added. Particularly, Ni and Co accumulated in the carbonates and exchangeable fractions ensuring potential bioavailability. Otherwise, the initial stock in the inoculum sludge sufficed to operate the process for nearly 1year without supplementation of trace elements and no significant sludge wash-out occurred. © 2012 Elsevier Ltd.

  17. Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Lopes, S.I.C.; Saikaly, P.E.; Lens, P.N.L.

    2012-01-01

    The leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4 g COD l(reactor)(-1) d(-1)) and sulfate at different COD/SO42- ratios. During the

  18. Effects of H2S/HS- on Stress Corrosion Cracking Behavior of X100 Pipeline Steel Under Simulated Sulfate-Reducing Bacteria Metabolite Conditions

    Science.gov (United States)

    Liu, Q.; Li, Z.; Liu, Z. Y.; Li, X. G.; Wang, S. Q.

    2017-04-01

    The effect of H2S/HS-, which simulates the main metabolites of sulfate-reducing bacteria (SRB), on the electrochemical and stress corrosion cracking (SCC) behaviors of X100 steel was investigated in a near-neutral solution. The results showed that different H2S/HS- contents mainly affected the cathodic process of X100 electrochemical corrosion. As the concentration of H2S/HS- increased, the corrosion potential was shifted negatively, the corrosion current density was considerably increased, and the corrosion rate was linearly increased. Different rust layers with shifting structures were formed under different conditions and had different effects on electrochemical behaviors. However, sulfide mainly promoted local corrosion processes. With the synergistic effects of stress and H2S/HS-, SCC susceptibility was considerably enhanced. The accelerated process of hydrogen evolution by sulfide was crucial in enhancing SCC processes. In brief, the trace H2S/HS- generated by SRB metabolites played a positive role in promoting SCC.

  19. Response of the sulfate-reducing community to the re-establishment of estuarine conditions in two contrasting soils: a mesocosm approach

    NARCIS (Netherlands)

    Miletto, M.; Loeb, R.; Antheunisse, A.M.; Bodelier, P.L.E.; Laanbroek, H.J.

    2010-01-01

    We studied the response of the sulfate-reducing prokaryote (SRP) communities to the experimental variation of salinity and tide in an outdoor mesocosm setup. Intact soil monoliths were collected at two areas of the Haringvliet lagoon (The Netherlands): one sampling location consisted of agricultural

  20. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Coyne, P.; Smith, G. [New Mexico State Univ., Las Cruces, NM (United States)

    1995-08-15

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

  1. Impact of elevated nitrate on sulfate-reducing bacteria: A comparative study of Desulfovibrio vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    He, Q.; He, Z.; Joyner, D.C.; Joachimiak, M.; Price, M.N.; Yang, Z.K.; Yen, H.-C. B.; Hemme, C. L.; Chen, W.; Fields, M.; Stahl, D. A.; Keasling, J. D.; Keller, M.; Arkin, A. P.; Hazen, T. C.; Wall, J. D.; Zhou, J.

    2010-07-15

    Sulfate-reducing bacteria have been extensively studied for their potential in heavy-metal bioremediation. However, the occurrence of elevated nitrate in contaminated environments has been shown to inhibit sulfate reduction activity. Although the inhibition has been suggested to result from the competition with nitrate-reducing bacteria, the possibility of direct inhibition of sulfate reducers by elevated nitrate needs to be explored. Using Desulfovibrio vulgaris as a model sulfate-reducing bacterium, functional genomics analysis reveals that osmotic stress contributed to growth inhibition by nitrate as shown by the upregulation of the glycine/betaine transporter genes and the relief of nitrate inhibition by osmoprotectants. The observation that significant growth inhibition was effected by 70 mM NaNO{sub 3} but not by 70 mM NaCl suggests the presence of inhibitory mechanisms in addition to osmotic stress. The differential expression of genes characteristic of nitrite stress responses, such as the hybrid cluster protein gene, under nitrate stress condition further indicates that nitrate stress response by D. vulgaris was linked to components of both osmotic and nitrite stress responses. The involvement of the oxidative stress response pathway, however, might be the result of a more general stress response. Given the low similarities between the response profiles to nitrate and other stresses, less-defined stress response pathways could also be important in nitrate stress, which might involve the shift in energy metabolism. The involvement of nitrite stress response upon exposure to nitrate may provide detoxification mechanisms for nitrite, which is inhibitory to sulfate-reducing bacteria, produced by microbial nitrate reduction as a metabolic intermediate and may enhance the survival of sulfate-reducing bacteria in environments with elevated nitrate level.

  2. Methods for Engineering Sulfate Reducing Bacteria of the Genus Desulfovibrio

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, Swapnil R; Keller, Kimberly L.; Wall, Judy D.

    2011-03-15

    Sulfate reducing bacteria are physiologically important given their nearly ubiquitous presence and have important applications in the areas of bioremediation and bioenergy. This chapter provides details on the steps used for homologous-recombination mediated chromosomal manipulation of Desulfovibrio vulgaris Hildenborough, a well-studied sulfate reducer. More specifically, we focus on the implementation of a 'parts' based approach for suicide vector assembly, important aspects of anaerobic culturing, choices for antibiotic selection, electroporation-based DNA transformation, as well as tools for screening and verifying genetically modified constructs. These methods, which in principle may be extended to other sulfate-reducing bacteria, are applicable for functional genomics investigations, as well as metabolic engineering manipulations.

  3. Effects of microbial activity and electron shuttles on the reduction of U(VI) under Fe(III)- and sulfate-reducing conditions

    Science.gov (United States)

    O'Loughlin, E. J.; Boyanov, M.; Kwon, M.; Long, P. E.; Williams, K. H.; Kemner, K. M.

    2009-12-01

    Recent studies suggest that electron shuttles such as low molecular mass quinones and humic substances may play a role in many redox reactions involved in contaminant transformations and the biogeochemical cycling of redox active elements in aquatic and terrestrial environments. In an effort to better define the role(s) of electron shuttles in biogeochemical processes in natural and engineered subsurface environments, we are investigating the effects of 9,10-anthraquinone-2,6-disulfonate (AQDS), a synthetic electron shuttle often used as a surrogate for quinone moieties in humic substances, on transformations of Fe, S, and U under conditions favorable for dissimilatory iron and sulfate reduction. Experiments were conducted in serum bottles containing a defined mineral medium amended with 30 mM Fe(III), 5 mM sulfate, and 10 mM acetate. Duplicate bottles with and without 100 μM AQDS were prepared. Fe(III) was provided as natural sienna, an iron-rich earth consisting primarily of quartz and goethite. The serum bottles were sparged with Ar and inoculated with sediment from the Rifle, CO Integrated Field Research Challenge (IFRC) site and monitored over time for Fe(II) production and sulfate and acetate consumption. After the system reached steady state with respect to Fe(III) and sulfate reduction, aliquots of suspension were collected from each system (i.e., with and without AQDS) for U(VI) reduction experiments. One set from each system was pasteurized at 70 °C for 1 hr; the other set was not pasteurized. The suspensions were spiked with 500 μM U(VI). After 48 h, 100% of the added U was removed from solution in the non-pasteurized AQDS system. However, only 58%, 25%, and 11% of added U was removed in the no AQDS non-pasteurized, AQDS pasteurized, and no AQDS pasteurized systems, respectively. U XANES analysis of the solids in each of these suspensions indicated that, with the exception of the pasteurized system without AQDS, the majority (85-95%) of the U

  4. Diversity of sulfur isotope fractionations by sulfate-reducing prokaryotes

    DEFF Research Database (Denmark)

    Detmers, Jan; Brüchert, Volker; Habicht, K S

    2001-01-01

    Batch culture experiments were performed with 32 different sulfate-reducing prokaryotes to explore the diversity in sulfur isotope fractionation during dissimilatory sulfate reduction by pure cultures. The selected strains reflect the phylogenetic and physiologic diversity of presently known...... sulfate reducers and cover a broad range of natural marine and freshwater habitats. Experimental conditions were designed to achieve optimum growth conditions with respect to electron donors, salinity, temperature, and pH. Under these optimized conditions, experimental fractionation factors ranged from 2.......0 to 42.0 per thousand. Salinity, incubation temperature, pH, and phylogeny had no systematic effect on the sulfur isotope fractionation. There was no correlation between isotope fractionation and sulfate reduction rate. The type of dissimilatory bisulfite reductase also had no effect on fractionation...

  5. Sulfate reducing potential in an estuarine beach

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Chandramohan, D.

    Sulfate reducing bacteria (SRB) and their activity (SRA) together with total anaerobic and aerobic bacterial flora were estimated during July 1982-April 1983 and July-August 1984 from 1, 3 and 5 cm depths using core samples. The average number (no...

  6. Pathway of Fermentative Hydrogen Production by Sulfate-reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

    2015-02-16

    Biofuels are a promising source of sustainable energy. Such biofuels are intermediate products of microbial metabolism of renewable substrates, in particular, plant biomass. Not only are alcohols and solvents produced in this degradative process but energy-rich hydrogen as well. Non photosynthetic microbial hydrogen generation from compounds other than sugars has not been fully explored. We propose to examine the capacity of the abundant soil anaerobes, sulfate-reducing bacteria, for hydrogen generation from organic acids. These apparently simple pathways have yet to be clearly established. Information obtained may facilitate the exploitation of other microbes not yet readily examined by molecular tools. Identification of the flexibility of the metabolic processes to channel reductant to hydrogen will be useful in consideration of practical applications. Because the tools for genetic and molecular manipulation of sulfate-reducing bacteria of the genus Desulfovibrio are developed, our efforts will focus on two strains, D. vulgaris Hildenborough and Desulfovibrio G20.Therefore total metabolism, flux through the pathways, and regulation are likely to be limiting factors which we can elucidate in the following experiments.

  7. Revisiting Modes of energy generation in sulfate reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Joachimiak, Marcin; Chakraborty, Romy; Zhou, Aifen; Fortney, Julian; Geller, Jil; Wall, Judy; Zhou, Jizhong; Arkin, Adam; Hazen, Terry; Keasling, Jay; Chhabra, Swapnil

    2010-05-17

    Sulfate reducing bacteria (SRB) play an important role in global sulfur and carbon cycling through their ability to completely mineralize organic matter while respiring sulfate to hydrogen sulfide. They are ubiquitous in anaerobic environments and have the ability to reduce toxic metals like Cr(VI) and U(VI). While SRB have been studied for over three decades, bioenergetic modes of this group of microbes are poorly understood. Desulfovibrio vulgaris strain Hildenborough (DvH) has served as a model SRB over the last decade with the accumulation of transcriptomic, proteomic and metabolic data under a wide variety of stressors. To further investigate the three hypothesized modes of energy generation in this anaerobe we conducted a systematic study involving multiple electron donor and acceptor combinations for growth. DvH was grown at 37oC in a defined medium with (a) lactate + thiosulfate, (b) lactate + sulfite (c) lactate + sulfate, (d) pyruvate + sulfate, (e) H2 + acetate + sulfate, (f) formate + acetate + sulfate, g) formate + sulfate and (h) pyruvate fermentation. Cells were harvested at mid-log phase of growth for all conditions for transcriptomics, when the optical density at 600nm was in the range 0.42-0.5. Initial results indicate that cells grown on lactate do not appear to significantly differentiate their gene expression profiles when presented with different electron acceptors. These profiles however differ significantly from those observed during growth with other electron donors such as H2 and formate, as well as during fermentative growth. Together the gene expression changes in the presence of different electron donors provide insights into the ability of DvH to differentially reduce metals such as Cr(VI). Here we present revised modes of energy generation in DvH in light of this new transcriptomic evidence.

  8. Nitrate reduction in sulfate-reducing bacteria.

    Science.gov (United States)

    Marietou, Angeliki

    2016-08-01

    Sulfate-reducing bacteria (SRBs) gain their energy by coupling the oxidation of organic substrate to the reduction of sulfate to sulfide. Several SRBs are able to use alternative terminal electron acceptors to sulfate such as nitrate. Nitrate-reducing SRBs have been isolated from a diverse range of environments. In order to be able to understand the significance of nitrate reduction in SRBs, we need to examine the ecology and physiology of the nitrate-reducing SRB isolates. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Mechanisms and Effectivity of Sulfate Reducing Bioreactors ...

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of which is the substrate composition. Chitinous materials have demonstrated high metal removal rates, particularly for the two recalcitrant MIW contaminants Zn and Mn, but their removal mechanisms need further study. We studied Cd, Fe, Zn, and Mn removal in bioactive and abiotic SRBRs to elucidate the metal removal mechanisms and the differences in metal and sulfate removal rates using a chitinous material as substrate. We found that sulfate-reducing bacteria are effective in increasing metal and sulfate removal rates and duration of operation in SRBRs, and that the main mechanism involved was metal precipitation as sulfides. The solid residues provided evidence of the presence of sulfides in the bioactive column, more specifically ZnS, according to XPS analysis. The feasibility of passive treatments with a chitinous substrate could be an important option for MIW remediation. Mining influenced water (MIW) remediation is still one of the top priorities for the agency because it addresses the most important environmental problem associated with the mining industry and that affects thousands of communities in the U.S. and worldwide. In this paper, the MIW bioremediation mechanisms are studied

  10. Anaerobic benzene degradation by Gram-positive sulfate-reducing bacteria.

    Science.gov (United States)

    Abu Laban, Nidal; Selesi, Drazenka; Jobelius, Carsten; Meckenstock, Rainer U

    2009-06-01

    Despite its high chemical stability, benzene is known to be biodegradable with various electron acceptors under anaerobic conditions. However, our understanding of the initial activation reaction and the responsible prokaryotes is limited. In the present study, we enriched a bacterial culture that oxidizes benzene to carbon dioxide under sulfate-reducing conditions. Community analysis using terminal restriction fragment length polymorphism, 16S rRNA gene sequencing and FISH revealed 95% dominance of one phylotype that is affiliated to the Gram-positive bacterial genus Pelotomaculum showing that sulfate-reducing Gram-positive bacteria are involved in anaerobic benzene degradation. In order to get indications of the initial activation mechanism, we tested the substrate utilization, performed cometabolism tests and screened for putative metabolites. Phenol, toluene, and benzoate could not be utilized as alternative carbon sources by the benzene-degrading culture. Cometabolic degradation experiments resulted in retarded rates of benzene degradation in the presence of phenol whereas toluene had no effect on benzene metabolism. Phenol, 2-hydroxybenzoate, 4-hydroxybenzoate, and benzoate were identified as putative metabolites in the enrichment culture. However, hydroxylated aromatics were shown to be formed abiotically. Thus, the finding of benzoate as an intermediate compound supports a direct carboxylation of benzene as the initial activation mechanism but additional reactions leading to its formation cannot be excluded definitely.

  11. Cometabolic transformation and cleavage of nitrodiphenylamines by three newly isolated sulfate-reducing bacterial strains.

    Science.gov (United States)

    Drzyzga, O; Schmidt, A; Blotevogel, K

    1996-05-01

    Three sulfate-reducing bacterial strains (Desulfovibrio sp. strain SHV, Desulfococcus sp. strain WHC, and Desulfomicrobium sp. strain WHB) with the capacity to cometabolize 2-nitrodiphenylamine, 4-nitrodiphenylamine, and 2,4-dinitrodiphenylamine were newly isolated. Before breaking down the diphenylamine structure, these strains cometabolically reduce the nitrodiphenylamines to the corresponding aminodiphenylamines during anaerobic oxidation of the growth substrate lactate (Desulfovibrio strain SHV and Desulfomicrobium strain WHC) or benzoate (Desulfococcus strain WHB), leading to the formation of aniline and a smaller quantity of methylaniline. These compounds were not further metabolized by the sulfate reducers. The anaerobic metabolism of aminodiphenylamines also led to the formation of heterocyclic condensation products such as phenazine and acridine derivatives, provided that they contained an amino group in the ortho position of the diphenylamine (e.g., 2-aminodiphenylamine or 2,4-diaminodiphenylamine). In addition, low levels of indole and benzothiazole derivatives were identified, but these also were not further metabolized by the three sulfate-reducing strains.

  12. The role of sulfate-reducing prokaryotes in the coupling of element biogeochemical cycling.

    Science.gov (United States)

    Bao, Peng; Li, Guo-Xiang; Sun, Guo-Xin; Xu, Yao-Yang; Meharg, Andrew A; Zhu, Yong-Guan

    2018-02-01

    Sulfate-reducing prokaryotes (SRP) represent a diverse group of heterotrophic and autotrophic microorganisms that are ubiquitous in anoxic habitats. In addition to their important role in both sulfur and carbon cycles, SRP are important biotic and abiotic regulators of a variety of sulfur-driven coupled biogeochemical cycling of elements, including: oxygen, nitrogen, chlorine, bromine, iodine and metal(loid)s. SRP gain energy form most of the coupling of element transformation. Once sulfate-reducing conditions are established, sulfide precipitation becomes the predominant abiotic mechanism of metal(loid)s transformation, followed by co-precipitation between metal(loid)s. Anthropogenic contamination, since the industrial revolution, has dramatically disturbed sulfur-driven biogeochemical cycling; making sulfur coupled elements transformation complicated and unpredictable. We hypothesise that sulfur might be detoxication agent for the organic and inorganic toxic compounds, through the metabolic activity of SRP. This review synthesizes the recent advances in the role of SRP in coupled biogeochemical cycling of diverse elements. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Monitoring sulfide and sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  14. Anaerobic degradation of benzoate by sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S.P.; Adorno, M.A.T.; Moraes, E.M.; Varesche, M.B.A. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Biological Processes Laboratory

    2004-07-01

    Anaerobic processes are an efficient way to degrade aromatic compounds in industrial wastewater, such as phenol, cresol and benzoate. This study characterized the bacteria that degrades benzoate, an anaerobic degradation intermediate of several complex aromatic compounds. In particular, the study assessed the capacity to use benzoate with sulfate reducing bacteria in mesophilic conditions. Biofilm from polyurethane foam matrices of a fixed bed reactor was used as the cellular inoculum to treat industrial wastewater containing organic peroxide. Dilution techniques were used to purify the material and obtain cultures of cocci. The benzoate consumption capacity in sulfidogenic conditions was observed when the purified inoculum was applied to batch reactors with different benzoate/sulfate relations. Results indicate that purification was positive to bacteria that can degrade aromatic compounds. Desulfococcus multivorans bacteria was identified following the physiologic and kinetic experiments. The 0.6 benzoate/sulfate relation was considered ideal for complete consumption of carbon and total use of sulfur. 10 refs., 3 figs.

  15. Sulfate-reducing bacteria inhabiting natural corrosion depostis from marine steel structures

    NARCIS (Netherlands)

    Païssé, S.; Ghiglione, J.-F.; Marty, F.; Abbas, B.; Gueuné, H.; Sanchez Amaya, J.; Muyzer, G.; Quillet, L.

    2013-01-01

    In the present study, investigations were conducted on natural corrosion deposits to better understand the role of sulfate-reducing bacteria (SRB) in the accelerated corrosion process of carbon steel sheet piles in port environments. We describe the abundance and diversity of total and metabolically

  16. Evidence for Coexistence of Two Distinct Functional Groups of Sulfate-Reducing Bacteria in Salt Marsh Sediment

    OpenAIRE

    Ibrahim M. Banat; Lindström, E. Börje; Nedwell, David B.; Balba, M. Talaat

    1981-01-01

    Oxidation of acetate in salt marsh sediment was inhibited by the addition of fluoroacetate, and also by the addition of molybdate, an inhibitor of sulfate-reducing bacteria. Molybdate had no effect upon the metabolism of acetate in a freshwater sediment in the absence of sulfate. The inhibitory effect of molybdate on acetate turnover in the marine sediment seemed to be because of its inhibiting sulfate-reducing bacteria which oxidized acetate to carbon dioxide. Sulfide was not recovered from ...

  17. FINAL REPORT - Biogeochemistry of Uranium Under Reducing and Re-oxidizing Conditions:An Integrated Laboratory and Field Study and Acceptable Endpoints for Metals and Radionuclides: Quantifying the Stability of Uranium and Lead Immobilized Under Sulfate Reducing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brent Peyton; James Amonette; Haluk Beyenal; Gill Geesey; Zbigniew Lewandowski; Rajesh Sani

    2005-10-07

    Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. In situ coupons with a variety of mineral phases were placed in monitoring wells at the NABIR FRC. These coupons showed that the mineral phase composition significantly affected the resulting attached phase microbial community. Our comparative use of both batch and open flow reactors (more representative of field conditions) indicates that hydrodynamics and continual influx of substrate and contaminants can also yield significantly different results than those obtained with closed serum bottles. To this end, the following overall experimental hypothesis tested was the following: On a mineral surface under anaerobic conditions, accumulations of secondary inorganic precipitates are controlled by a) the bacteria associated with the mineral surface, b) the electron acceptors available for anaerobic bacterial respiration, and c) local hydrodynamics and pH buffers govern micro- and meso-scale interaction of U in the presence of electron donors and acceptors, and nutrients.

  18. Thermophilic Sulfate-Reducing Bacteria in Cold Marine Sediment

    DEFF Research Database (Denmark)

    ISAKSEN, MF; BAK, F.; JØRGENSEN, BB

    1994-01-01

    Sulfate reduction was measured with the (SO42-)-S-35-tracer technique in slurries of sediment from Aarhus Bay, Denmark, where seasonal temperatures range from 0 degrees to 15 degrees C. The incubations were made at temperatures from 0 degrees C to 80 degrees C in temperature increments of 2 degrees...... C to search for presence of psychrophilic, mesophilic and thermophilic sulfate-reducing bacteria. Detectable activity was initially only in the mesophilic range, but after a lag phase sulfate reduction by thermophilic sulfate-reducing bacteria were observed. No distinct activity of psychrophilic...... sulfate-reducing bacteria was detected. Time course experiments showed constant sulfate reduction rates at 4 degrees C and 30 degrees C, whereas the activity at 60 degrees C increased exponentially after a lag period of one day. Thermophilic, endospore-forming sulfate-reducing bacteria, designated strain...

  19. Selenate removal in methanogenic and sulfate-reducing upflow anaerobic sludge bed reactors

    NARCIS (Netherlands)

    Lenz, M.; Hullebusch, van E.D.; Hommes, G.; Corvini, P.F.X.; Lens, P.N.L.

    2008-01-01

    This paper evaluates the use of upflow anaerobic sludge bed (UASB) bioreactors (30 degrees C, pH = 7.0) to remove selenium oxyanions from contaminated waters (790 mu g Se L-1) under methanogenic and sulfate-reducing conditions using lactate as electron donor. One UASB reactor received sulfate at

  20. Characterization of sulfate reducing bacteria isolated from urban soil

    Science.gov (United States)

    Zhang, Mingliang; Wang, Haixia

    2017-05-01

    Sulfate reducing bacteria (SRB) was isolated from urban soil and applied for the remediation of heavy metals pollution from acid mine drainage. The morphology and physiological characteristics (e.g. pH and heavy metals tolerance) of SRB was investigated. The SRB was gram-negative bacteria, long rod with slight curve, cell size 0.5× (1.5-2.0) μm. The pH of medium had significant effect on SRB growth and the efficiency of sulfate reduction, and it showed that the suitable pH range was 5-9 and SRB could not survive at pH less than 4. The maximum tolerance of Fe (II), Zn (II), Cd (II), and Cu (II) under acidic condition (pH 5.0) was about 600 mg/L, 150 mg/L, 25 mg/L and 25 mg/L, respectively. The result indicated that SRB isolated in this study could be used for the bioremediation of acid mine drainage (pH>4) within the heavy metals concentrations tolerance.

  1. Factors Governing the Germination of Sulfate-Reducing Desulfotomaculum Endospores Involved in Oil Reservoir Souring.

    Science.gov (United States)

    Sherry, A.; Bell, E.; Cueto, G.; Suarez-Suarez, A.; Pilloni, G.; Hubert, C. R.

    2015-12-01

    Reservoir souring is caused by the activity of sulfate-reducing microorganisms (SRM) in subsurface oil reservoirs, and is often induced by seawater injection during secondary oil recovery. Souring can potentially contribute to corrosion of infrastructure, health and safety hazards to the workforce, and reduction in value by increasing refining costs associated with producing the oil resource. Souring causes annual losses in the billions of dollars to the oil industry. Endospore-forming SRM, such as Desulfotomaculum spp., are often suspected culprits in reservoir souring. Endospores can survive unfavourable conditions for long periods, yet remain poised to germinate and become active if conditions become more favourable. Factors governing endospore germination are poorly understood, but are thought to include availability of nutrients, possibly metabolic by products of other anaerobic bioprocesses, and/or variations in temperature. Most research has focused on aerobic Bacillus spp., with very few studies dedicated to spore germination among anaerobes (order Clostridiales) including the sulfate-reducing Desulfotomaculum found in anoxic subsurface petroleum reservoirs. For Desulfotomaculum spores in deep hot oil reservoirs, cold seawater introduction during secondary oil recovery may create thermal viability zones for sulfate reduction near the injection wellbore. To evaluate these processes, sulfate-containing microcosms were prepared with different marine sediments as a source of spores, and amended with organic substrates in the presence or absence of oil. Incubation at 80°C for six days was followed by a down-shift in temperature to 60°C to mimic cold seawater injection into a hot reservoir. Souring did not occur at 80°C, but commenced within hours at 60°C. Microcosms were monitored for sulfate reduction and organic acids in combination with next generation sequencing of 16S rRNA genes (Ion Torrent, Illumina MiSeq). Through a combination of high

  2. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    Science.gov (United States)

    Hauri, James F.; Schaider, Laurel A.

    2009-01-01

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

  3. Stable carbon isotope fractionation by sulfate-reducing bacteria

    Science.gov (United States)

    Londry, Kathleen L.; Des Marais, David J.

    2003-01-01

    Biogeochemical transformations occurring in the anoxic zones of stratified sedimentary microbial communities can profoundly influence the isotopic and organic signatures preserved in the fossil record. Accordingly, we have determined carbon isotope discrimination that is associated with both heterotrophic and lithotrophic growth of pure cultures of sulfate-reducing bacteria (SRB). For heterotrophic-growth experiments, substrate consumption was monitored to completion. Sealed vessels containing SRB cultures were harvested at different time intervals, and delta(13)C values were determined for gaseous CO(2), organic substrates, and products such as biomass. For three of the four SRB, carbon isotope effects between the substrates, acetate or lactate and CO(2), and the cell biomass were small, ranging from 0 to 2 per thousand. However, for Desulfotomaculum acetoxidans, the carbon incorporated into biomass was isotopically heavier than the available substrates by 8 to 9 per thousand. SRB grown lithoautotrophically consumed less than 3% of the available CO(2) and exhibited substantial discrimination (calculated as isotope fractionation factors [alpha]), as follows: for Desulfobacterium autotrophicum, alpha values ranged from 1.0100 to 1.0123; for Desulfobacter hydrogenophilus, the alpha value was 0.0138, and for Desulfotomaculum acetoxidans, the alpha value was 1.0310. Mixotrophic growth of Desulfovibrio desulfuricans on acetate and CO(2) resulted in biomass with a delta(13)C composition intermediate to that of the substrates. The extent of fractionation depended on which enzymatic pathways were used, the direction in which the pathways operated, and the growth rate, but fractionation was not dependent on the growth phase. To the extent that environmental conditions affect the availability of organic substrates (e.g., acetate) and reducing power (e.g., H(2)), ecological forces can also influence carbon isotope discrimination by SRB.

  4. Sulfate-reducing prokaryotic communities in two deep hypersaline anoxic basins in the Eastern Mediterranean deep sea

    NARCIS (Netherlands)

    van der Wielen, Paul W. J. J.; Heljs, Sander K.

    In the Eastern Mediterranean Sea, deep hypersaline anoxic basins (DHABs) and deep-sea sediment contain anoxic environments where sulfate reduction is an important microbial metabolic process. The objective of this study was to characterize the sulfate-reducing community in the brine and interface of

  5. Trace-element deposition in the Cariaco Basin, Venezuela Shelf, under sulfate-reducing conditions: a history of the local hydrography and global climate, 20 ka to the present

    Science.gov (United States)

    Piper, David Z.; Dean, Walter E.

    2002-01-01

    A sediment core from the Cariaco Basin on the Venezuelan continental shelf, which recovered sediment that has been dated back to 20 ka (thousand years ago), was examined for its major-element-oxide and trace-element composition. Cadmium (Cd), chromium (Cr), copper (Cu), molybdenum (Mo), nickel (Ni), vanadium (V), and zinc (Zn) can be partitioned between a siliciclastic, terrigenous-derived fraction and two seawater-derived fractions. The two marine fractions are (1) a biogenic fraction represented by nutrient trace elements taken up mostly in the photic zone by phytoplankton, and (2) a hydrogenous fraction that has been derived from bottom water via adsorption and precipitation reactions. This suite of trace elements contrasts with a second suite of trace elements—barium (Ba), cobalt (Co), gallium (Ga), lithium (Li), the rare-earth elements, thorium (Th), yttrium (Y), and several of the major-element oxides—that has had solely a terrigenous source. The partitioning scheme, coupled with bulk sediment accumulation rates measured by others, allows us to determine the accumulation rate of trace elements in each of the three sediment fractions and of the fractions themselves. The current export of organic matter from the photic zone, redox conditions and advection of bottom water, and flux of terrigenous debris into the basin can be used to calculate independently trace-element depositional rates. The calculated rates show excellent agreement with the measured rates of the surface sediment. This agreement supports a model of trace-element accumulation rates in the subsurface sediment that gives a 20-kyr history of upwelling into the photic zone (that is, primary productivity), bottom-water advection and redox, and provenance. Correspondence of extrema in the geochemical signals with global changes in sea level and climate demonstrates the high degree to which the basin hydrography and provenance have responded to the paleoceanographic and paleoclimatic regimes of

  6. Adaptation of psychrophilic and psychrotrophic sulfate-reducing bacteria to permanently cold marine environments

    DEFF Research Database (Denmark)

    Isaksen, MF; Jørgensen, BB

    1996-01-01

    environments, In sediment slurries from Antarctica, the metabolic activity of psychrotrophic bacteria was observed with a respiration optimum at 18 to 19 degrees C during short-term incubations, However, over a 1-week incubation, the highest respiration rate was observed at 12.5 degrees C. Growth...... compared with those obtained from pure cultures of sulfate-reducing bacteria by using the psychrotrophic strain Itk10 and the mesophilic strain ak30. The psychrotrophic strain reduced sulfate optimally at 28 degrees C in short-term incubations, even though it could not grow at temperatures above 24 degrees...

  7. Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria.

    Science.gov (United States)

    Li, Yongchao; Hu, Xiaoxian; Ren, Bozhi

    2016-01-01

    The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb(2)S(3) precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration.

  8. Corrosion of Iron by Sulfate-Reducing Bacteria: New Views of an Old Problem

    Science.gov (United States)

    Garrelfs, Julia

    2014-01-01

    About a century ago, researchers first recognized a connection between the activity of environmental microorganisms and cases of anaerobic iron corrosion. Since then, such microbially influenced corrosion (MIC) has gained prominence and its technical and economic implications are now widely recognized. Under anoxic conditions (e.g., in oil and gas pipelines), sulfate-reducing bacteria (SRB) are commonly considered the main culprits of MIC. This perception largely stems from three recurrent observations. First, anoxic sulfate-rich environments (e.g., anoxic seawater) are particularly corrosive. Second, SRB and their characteristic corrosion product iron sulfide are ubiquitously associated with anaerobic corrosion damage, and third, no other physiological group produces comparably severe corrosion damage in laboratory-grown pure cultures. However, there remain many open questions as to the underlying mechanisms and their relative contributions to corrosion. On the one hand, SRB damage iron constructions indirectly through a corrosive chemical agent, hydrogen sulfide, formed by the organisms as a dissimilatory product from sulfate reduction with organic compounds or hydrogen (“chemical microbially influenced corrosion”; CMIC). On the other hand, certain SRB can also attack iron via withdrawal of electrons (“electrical microbially influenced corrosion”; EMIC), viz., directly by metabolic coupling. Corrosion of iron by SRB is typically associated with the formation of iron sulfides (FeS) which, paradoxically, may reduce corrosion in some cases while they increase it in others. This brief review traces the historical twists in the perception of SRB-induced corrosion, considering the presently most plausible explanations as well as possible early misconceptions in the understanding of severe corrosion in anoxic, sulfate-rich environments. PMID:24317078

  9. Sulfamethoxazole degradation in anaerobic sulfate-reducing bacteria sludge system.

    Science.gov (United States)

    Jia, Yanyan; Khanal, Samir Kumar; Zhang, Huiqun; Chen, Guang-Hao; Lu, Hui

    2017-08-01

    Sulfamethoxazole (SMX) is one of the most commonly used antibiotics. SMX degradation in sulfate-reducing bacteria (SRB) sludge systems has not been reported so far. This research investigated the SMX degradation using SRB sludge in a sulfate-reducing up-flow sludge bed reactor. Moreover, the mechanisms and kinetics of SMX removal were also investigated using SRB sludge via a series of batch experiments. The results showed that SMX removal was characterized by a rapid sorption onto SRB sludge, and desorption from SRB sludge to aqueous phase until achieving equilibrium, and then followed by slow biodegradation. Biodegradation was the dominant route for SMX removal. The sorption process conformed well to a pseudo-second-order kinetic model, meaning that the sorption occurred primarily via a chemical sorption process. The removal of SMX followed the pseudo-zero-order kinetic model with a specific removal rate of 13.2 ± 0.1 μg/L/d at initial SMX concentration 100 μg/L in batch tests. Based on the analysis of metabolites, most of the SMX biotransformation products' structures altered in the isoxazole ring, which were significantly different from that produced by aerobic and anaerobic sludge systems. Thus, SRB sludge system could play an important role in SMX biodegradation, especially in Sulfate-reduction Autotrophic denitrification and Nitrification Integrated (SANI) process for sewage treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Isolation and identification of sulfate reducing bacteria (SRB) from the sediment pond after a coal mine in Samarinda, East Kalimantan

    Science.gov (United States)

    Kusumawati, Eko; Sudrajat, Putri, Junita Susilaning

    2017-02-01

    Title isolation and identification of sulfate reducing bacteria (SRB) of sediment pond former coal mine in Samarinda, East Kalimantan. Sulfate reducing bacteria (SRB) is a group of microbes that can be used to improve the quality of sediment former coal mine. In the metabolic activities, the SRB can reduce sulfate to H2S which immediately binds to metals that are widely available on mined lands and precipitated in the form of metal sulfides reductive. Isolation and identification of sulfate reducing bacteria carried out in the Laboratory of Microbiology and Molecular Genetics, Faculty of Mathematics and Natural Sciences, University of Mulawarman, Samarinda. Postgate B is a liquid medium used for isolation through serial dilution. Physiological and biochemical characterization was done by Bergey's Manual of Determinative Bacteriology. Six isolates of sulfate reducing bacteria were isolated from the sediment pond former coal mine in Samarinda. Several groups of bacteria can grow at 14 days of incubation, however, another group of bacteria which takes 21 days to grow. The identification results showed that two isolates belong to the genus Desulfotomaculum sp., and each of the other isolates belong to the genus Desulfococcus sp., Desulfobacter sp., Desulfobulbus sp. and Desulfobacterium sp.

  11. Assessing the Role of Iron Sulfides in the Long Term Sequestration of U by Sulfate Reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Bruce; Zhou, Chen; Vannela, Raveender

    2013-12-31

    This four-year project’s overarching aim was to identify the role of biogenic and synthetic iron-sulfide minerals in the long-term sequestration of reduced U(IV) formed under sulfate-reducing conditions when subjected to re-oxidizing conditions. As stated in this final report, significant progress was achieved through the collaborative research effort conducted at Arizona State University (ASU) and the University of Michigan (UM).

  12. A Marine Sulfate-Reducing Bacterium Producing Multiple Antibiotics: Biological and Chemical Investigation

    Directory of Open Access Journals (Sweden)

    Xiaoliang Wang

    2009-07-01

    Full Text Available A marine sulfate-reducing bacterium SRB-22 was isolated by means of the agar shake dilution method and identified as Desulfovibrio desulfuricans by morphological, physiological and biochemical characteristics and 16S rDNA analysis. In the bioassay, its extract showed broad-spectrum antimicrobial activity using the paper disc agar diffusion method. This isolate showed a different antimicrobial profile than either ampicillin or nystatin and was found to produce at least eight antimicrobial components by bioautography. Suitable fermentation conditions for production of the active constituents were determined to be 28 day cultivation at 25 °C to 30 °C with a 10% inoculation ratio. Under these conditions, the SRB-22 was fermented, extracted and chemically investigated. So far an antimicrobial compound, mono-n-butyl phthalate, and an inactive compound, thymine, have been isolated and characterized.

  13. [Biodiversity of sulfate-reducing bacteria growing on objects of heating systems].

    Science.gov (United States)

    Purish, L M; Asaulenko, L G; Abdulina, D R; Iutinskaia, G A

    2014-01-01

    It was shown that sulfate-reducing bacteria developed on the sections of Kyiv municipal heating systems, which are exploited in conditions of different temperatures. The bacteria were different as to their morphological and physiological properties. The bacteria of Desulfovibrio genus were revealed on the sections, which were exploited at a temperature of 35-40 degrees C and bacteria of Desulfomicrobium and Desulfotomaculum genera were revealed on the sections with a higher temperature such as 60 degrees C. Based on of the 16S rRNA gene analysis data, it was demonstrated that sequences of TC2, TC3 and TC4 clones related to Desulfovibrio sp. DSM 12803 (100% sequence similarity), Desulfotomaculum sp. ECP-C-5 (92% sequence similarity) and Desulfomicrobium baculatum strain DSM 2555 (99% sequence similarity), respectively. The identified bacteria are potentially dangerous for heating systems and can be the agents of microbial corrosion.

  14. Sulfate-reducing bacteria influence the nucleation and growth of mackinawite and greigite

    Science.gov (United States)

    Picard, Aude; Gartman, Amy; Clarke, David R.; Girguis, Peter R.

    2018-01-01

    Sedimentary iron sulfide minerals play a key role in maintaining the oxygenation of Earth's atmosphere over geological timescales; they also record critical geochemical information that can be used to reconstruct paleo-environments. On modern Earth, sedimentary iron sulfide mineral formation takes places in low-temperature environments and requires the production of free sulfide by sulfate-reducing microorganisms (SRM) under anoxic conditions. Yet, most of our knowledge on the properties and formation pathways of iron sulfide minerals, including pyrite, derives from experimental studies performed in abiotic conditions, and as such the role of biotic processes in the formation of sedimentary iron sulfide minerals is poorly understood. Here we investigate the role of SRM in the nucleation and growth of iron sulfide minerals in laboratory experiments. We set out to test the hypothesis that SRM can influence Fe-S mineralization in ways other than providing sulfide through the comparison of the physical properties of iron sulfide minerals precipitated in the presence and in the absence of the sulfate-reducing bacterium Desulfovibrio hydrothermalis AM13 under well-controlled conditions. X-ray diffraction and microscopy analyses reveal that iron sulfide minerals produced in the presence of SRM exhibit unique morphology and aggregate differently than abiotic minerals formed in media without cells. Specifically, mackinawite growth is favored in the presence of both live and dead SRM, when compared to the abiotic treatments tested. The cell surface of live and dead SRM, and the extracellular polymers produced by live cells, provide templates for the nucleation of mackinawite and favor mineral growth. The morphology of minerals is however different when live and dead cells are provided. The transformation of greigite from mackinawite occurred after several months of incubation only in the presence of live SRM, suggesting that SRM might accelerate the kinetics of greigite

  15. MOLECULAR PHYLOGENETIC AND BIOGEOCHEMICAL STUDIES OF SULFATE-REDUCING BACTERIA IN THE RHIZOSPHERE OF SPARTINA ALTERNIFLORA

    Science.gov (United States)

    The population composition and biogeochemistry of sulfate-reducing bacteria (SRB) in the rhizosphere of the marsh grass Spartina alterniflora was investigated over two growing seasons using molecular probing, enumerations of culturable SRB, and measurements of SO42- reduction rat...

  16. Ambient iron concentration regulates the sulfate reducing activity in the mangrove swamps of Diwar, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Attria, K.; Kerkar,S.; LokaBharathi, P.A.

    In order to test the hypothesis that the ambient iron concentrations could regulate sulfate reducing activity (SRA) in mangrove areas, 10 cm cores were examined from test and reference sites. The test site at Diwar mangrove ecosystem is highly...

  17. Biosynthesis of CdS nanoparticles: A fluorescent sensor for sulfate-reducing bacteria detection.

    Science.gov (United States)

    Qi, Peng; Zhang, Dun; Zeng, Yan; Wan, Yi

    2016-01-15

    CdS nanoparticles were synthesized with an environmentally friendly method by taking advantage of the characteristic metabolic process of sulfate-reducing bacteria (SRB), and used as fluorescence labels for SRB detection. The presence of CdS nanoparticles was observed within and immediately surrounded bacterial cells, indicating CdS nanoparticles were synthesized both intracellularly and extracellularly. Moreover, fluorescent properties of microbial synthesized CdS nanoparticles were evaluated for SRB detection, and a linear relationship between fluorescence intensity and the logarithm of bacterial concentration was obtained in the range of from 1.0×10(2) to 1.0×10(7)cfu mL(-1). The proposed SRB detection method avoided the use of biological bio-recognition elements which are easy to lose their specific recognizing abilities, and the bacterial detection time was greatly shortened compared with the widely used MPN method which would take up to 15 days to accomplish the detection process. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Sulfate reducing bacteria detection in gas pipelines; Deteccao de bacterias redutoras de sulfato em gasodutos

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbach, Marcia Teresa S.; Oliveira, Ana Lucia C. de; Cavalcanti, Eduardo H. de S. [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil). Div. de Corrosao e Degradacao]. E-mails: marciasl@int.gov.br; analucia@int.gov.br; eduardoh@int.gov.br

    2004-07-01

    Microbiology induced corrosion (MIC) process associated with sulfate reducing bacteria (BRS) are one of the most important matter of concern for the oil and gas industry as 77% of failures have been attributed this sort of degradation. Corrosion products found present in gas transportation pipelines, the so-called 'black-powder' problem, are also a nuisance and source of economic losses for the gas industry. According to the literature, the incidence of black-powder can be ascribed to the metabolism of BRS that can be found in the gas environment. Integrity monitoring programs of gas pipelines adopt pigging as an important tool for internal corrosion monitoring. Solid residue such as the black-powder, collected by pigging, as well as the condensed, can be seen as a very valuable samples for microbiological analyses that can be used to detect and quantify bacteria related to the incidence of MIC processes. In the present work results concerning samples collected by pigging and condensed are presented. Small populations of viable BRS have been found in the pipeline. It can be seen that the inclusion of microbiological analyses of solid and liquid residues as a complementary action in the integrity monitoring programs adopted by gas transportation industry can be very helpful on the decision making concerning preventive and corrective actions to be taken in order to maintain the CIM processes under control. (author)

  19. Preparation of a Novel Nano or Submicron Tourmaline Ceramic and Its Ability to Inhibit the Activity of the Sulfate-Reducing Bacterium

    Science.gov (United States)

    Li, Chun-ying

    2017-07-01

    In this study, novel nano- or submicron-scale tourmaline bacteriostatic ceramics in which nano or submicron tourmaline is one of the central materials, together with nano-zinc oxide, are prepared using ion exchange and solid-phase synthesis techniques. The material is then examined with IR, XRD and XPS and is tested for the ability to inhibit the activity of the sulfate-reducing bacterium (SRB). The calcination temperature of the ceramic is 600 °C, and the main components are present at 11.17% for Si2p, 3.12% for Mo3d, 3.47% for Zn2p3, 2.86% for Mn2p and 2.35% for Cu2p. Additionally, the density of this material is 1.4-3.5 g/cm3, and its compressive strength exceeds 5.2 MPa, meeting the requirements of ceramic standards. Consequently, the bacteriostatic ceramic inhibits the activity of the sulfate-reducing bacterium effectively without inhibiting the removal of COD and NO3 -. These results indicate that the sulfate-reducing bacterium maintains its functional metabolism, apart from its sulfate reduction potential, when using this bacteriostatic ceramic, thus achieving the goal of inhibiting the action of the sulfate-reducing bacterium.

  20. Paediatric Metabolic Conditions of the Liver

    Directory of Open Access Journals (Sweden)

    Elroy P. Weledji

    2015-01-01

    Full Text Available Paediatric metabolic disorders with the most clinical manifestations of deranged hepatic metabolism are discussed. The conditions which will be stressed are those for which effective treatment is available and early diagnosis is essential. Accurate diagnosis of other disorders for which no treatment is, as yet, available is also important as a guide to prognosis and for accurate genetic counselling. With the advancement in amniocentesis techniques there is a growing role for gene therapy. For selected metabolic disorders, paediatric liver transplantations have been successful.

  1. Assessing the Role of Iron Sulfides in the Long Term Sequestration of Uranium by Sulfate-Reducing Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, Kim F. [Univ. of Michigan, Ann Arbor, MI (United States); Bi, Yuqiang [Univ. of Michigan, Ann Arbor, MI (United States); Carpenter, Julian [Univ. of Michigan, Ann Arbor, MI (United States); Hyng, Sung Pil [Univ. of Michigan, Ann Arbor, MI (United States); Rittmann, Bruce E. [Arizona State Univ., Tempe, AZ (United States); Zhou, Chen [Arizona State Univ., Tempe, AZ (United States); Vannela, Raveender [Arizona State Univ., Tempe, AZ (United States); Davis, James A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-12-31

    This overarching aim of this project was to identify the role of biogenic and synthetic iron-sulfide minerals in the long-term sequestration of reduced U(IV) formed under sulfate-reducing conditions when subjected to re-oxidizing conditions. The work reported herein was achieved through the collaborative research effort conducted at Arizona State University (ASU) and the University of Michigan (UM). Research at ASU, focused on the biogenesis aspects, examined the biogeochemical bases for iron-sulfide production by Desulfovibrio vulgaris, a Gram-negative bacterium that is one of the most-studied strains of sulfate-reducing bacteria. A series of experimental studies were performed to investigate comprehensively important metabolic and environmental factors that affect the rates of sulfate reduction and iron-sulfide precipitation, the mineralogical characteristics of the iron sulfides, and how uranium is reduced or co-reduced by D. vulagaris. FeS production studies revealed that controlling the pH affected the growth of D. vulgaris and strongly influenced the formation and growth of FeS solids. In particular, lower pH produced larger-sized mackinawite (Fe1+xS). Greater accumulation of free sulfide, from more sulfate reduction by D. vulgaris, also led to larger-sized mackinawite and stimulated mackinawite transformation to greigite (Fe3S4) when the free sulfide concentration was 29.3 mM. On the other hand, using solid Fe(III) (hydr)oxides as the iron source led to less productivity of FeS due to their slow and incomplete dissolution and scavenging of sulfide. Furthermore, sufficient free Fe2+, particularly during Fe(III) (hydr)oxide reductions, led to the additional formation of vivianite [Fe3(PO4)2•8(H2O)]. The U(VI) reduction studies revealed that D. vulgaris reduced U(VI) fastest when accumulating sulfide from concomitant sulfate reduction, since direct enzymatic and sulfide

  2. Influence of calcareous deposit on corrosion behavior of Q235 carbon steel with sulfate-reducing bacteria

    Science.gov (United States)

    Zhang, Jie; Li, Xiaolong; Wang, Jiangwei; Xu, Weichen; Duan, Jizhou; Chen, Shougang; Hou, Baorong

    2017-12-01

    Cathodic protection is a very effective method to protect metals, which can form calcareous deposits on metal surface. Research on the interrelationship between fouling organism and calcareous deposits is very important but very limited, especially sulfate-reducing bacteria (SRB). SRB is a kind of very important fouling organism that causes microbial corrosion of metals. A study of the influence of calcareous deposit on corrosion behavior of Q235 carbon steel in SRB-containing culture medium was carried out using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and surface spectroscopy (EDS). The calcareous deposit was formed with good crystallinity and smooth surface under the gradient current density of -30 μA cm-2 in natural seawater for 72 h. Our results can help elucidate the formation of calcareous deposits and reveal the interrelationship between SRB and calcareous deposits under cathodic protection. The results indicate that the corrosion tendency of carbon steel was obviously affected by Sulfate-reducing Bacteria (SRB) metabolic activity and the calcareous deposit formed on the surface of carbon steel under cathodic protection was favourable to reduce the corrosion rate. Calcareous deposits can promote bacterial adhesion before biofilm formation. The results revealed the interaction between biofouling and calcareous deposits, and the anti-corrosion ability was enhanced by a kind of inorganic and organic composite membranes formed by biofilm and calcareous deposits.

  3. Toward a rigorous network of protein-protein interactions of the model sulfate reducer Desulfovibrio vulgaris Hildenborough

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, S.R.; Joachimiak, M.P.; Petzold, C.J.; Zane, G.M.; Price, M.N.; Gaucher, S.; Reveco, S.A.; Fok, V.; Johanson, A.R.; Batth, T.S.; Singer, M.; Chandonia, J.M.; Joyner, D.; Hazen, T.C.; Arkin, A.P.; Wall, J.D.; Singh, A.K.; Keasling, J.D.

    2011-05-01

    Protein–protein interactions offer an insight into cellular processes beyond what may be obtained by the quantitative functional genomics tools of proteomics and transcriptomics. The aforementioned tools have been extensively applied to study E. coli and other aerobes and more recently to study the stress response behavior of Desulfovibrio 5 vulgaris Hildenborough, a model anaerobe and sulfate reducer. In this paper we present the first attempt to identify protein-protein interactions in an obligate anaerobic bacterium. We used suicide vector-assisted chromosomal modification of 12 open reading frames encoded by this sulfate reducer to append an eight amino acid affinity tag to the carboxy-terminus of the chosen proteins. Three biological replicates of the 10 ‘pulled-down’ proteins were separated and analyzed using liquid chromatography-mass spectrometry. Replicate agreement ranged between 35% and 69%. An interaction network among 12 bait and 90 prey proteins was reconstructed based on 134 bait-prey interactions computationally identified to be of high confidence. We discuss the biological significance of several unique metabolic features of D. vulgaris revealed by this protein-protein interaction data 15 and protein modifications that were observed. These include the distinct role of the putative carbon monoxide-induced hydrogenase, unique electron transfer routes associated with different oxidoreductases, and the possible role of methylation in regulating sulfate reduction.

  4. Polysulfide reduction by Clostridium relatives isolated from sulfate-reducing enrichment cultures.

    Science.gov (United States)

    Takahashi, Yui; Suto, Koichi; Inoue, Chihiro

    2010-04-01

    Sulfur is almost insoluble in water at ambient temperatures, and therefore polysulfide (S(n)(2-)) has been considered as a possible intermediate that is used directly by bacteria in sulfur respiration. Sulfur-reducing reductases have been purified and characterized from a few sulfur reducers. However, polysulfide reduction has only been confirmed in Wolinella succinogenes. In our previous study, the direct production of hydrogen sulfide from polysulfide was confirmed by an enrichment culture obtained from natural samples under sulfate-reducing conditions. The present study attempted to isolate and identify polysulfide-reducing bacteria from the enrichment cultures. Almost all the isolated strains were classified into the genus Clostridium, based on 16S rRNA gene sequence analysis. The isolates, and some closely related strains, were able to reduce polysulfide to hydrogen sulfide. During production of 1 mol of hydrogen sulfide, approximately 2 mol of lactate was converted to acetate. Thus, dissimilatory polysulfide reduction occurred using lactate as an electron donor. The ability to reduce elemental sulfur was also examined with the isolates and the related strains. Although elemental sulfur reducing strains can reduce polysulfides, not all polysulfide-reducing strains can reduce elemental sulfur. These results demonstrate that the conversion of elemental sulfur to polysulfide seems to be important in the reduction process of sulfur. Copyright 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Anaerobic degradation of cyclohexane by sulfate-reducing bacteria from hydrocarbon-contaminated marine sediments

    Directory of Open Access Journals (Sweden)

    Ulrike eJaekel

    2015-02-01

    Full Text Available The fate of cyclohexane, often used as a model compound for the biodegradation of cyclic alkanes due to its abundance in crude oils, in anoxic marine sediments has been poorly investigated. In the present study, we obtained an enrichment culture of cyclohexane-degrading sulfate-reducing bacteria from hydrocarbon-contaminated intertidal marine sediments. Microscopic analyses showed an apparent dominance by oval cells of 1.5×0.8 m. Analysis of a 16S rRNA gene library, followed by whole-cell hybridization with group- and sequence-specific oligonucleotide probes showed that these cells belonged to a single phylotype, and were accounting for more than 80% of the total cell number. The dominant phylotype, affiliated with the Desulfosarcina-Desulfococcus cluster of the Deltaproteobacteria, is proposed to be responsible for the degradation of cyclohexane. Quantitative growth experiments showed that cyclohexane degradation was coupled with the stoichiometric reduction of sulfate to sulfide. Substrate response tests corroborated with hybridization with a sequence-specific oligonucleotide probe suggested that the dominant phylotype apparently was able to degrade other cyclic and n-alkanes, including the gaseous alkanes propane and n-butane. Based on GC-MS analyses of culture extracts cyclohexylsuccinate was identified as a metabolite, indicating an activation of cyclohexane by addition to fumarate. Other metabolites detected were 3-cyclohexylpropionate and cyclohexanecarboxylate providing evidence that the overall degradation pathway of cyclohexane under anoxic conditions is analogous to that of n-alkanes.

  6. Streptomyces lunalinharesii 235 prevents the formation of a sulfate-reducing bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Juliana Pacheco da Rosa

    Full Text Available ABSTRACT Streptomyces lunalinharesii strain 235 produces an antimicrobial substance that is active against sulfate reducing bacteria, the major bacterial group responsible for biofilm formation and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance for sulfate reducing bacteria control is therefore a promising alternative to chemical biocides. In this study the antimicrobial substance did not interfere with the biofilm stability, but the sulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel coupons treated with the antimicrobial substance when compared to the untreated control. A reduction in the most probable number counts of planktonic cells of sulfate reducing bacteria was observed after treatments with the sub-minimal inhibitory concentration, minimal inhibitory concentration, and supra-minimal inhibitory concentration of the antimicrobial substance. Additionally, when the treated coupons were analyzed by scanning electron microscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The coupons used for the biofilm formation had a small weight loss after antimicrobial substance treatment, but corrosion damage was not observed by scanning electron microscopy. The absence of the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrio alaskensis was not able to adhere to the coupons. This is the first report on an antimicrobial substance produced by Streptomyces active against sulfate reducing bacteria biofilm formation. The application of antimicrobial substance as a potential biocide for sulfate reducing bacteria growth control could be of great interest to the petroleum industry.

  7. Microbial methanogenesis in the sulfate-reducing zone of sediments in the Eckernförde Bay, SW Baltic Sea

    Science.gov (United States)

    Maltby, Johanna; Steinle, Lea; Löscher, Carolin R.; Bange, Hermann W.; Fischer, Martin A.; Schmidt, Mark; Treude, Tina

    2018-01-01

    Benthic microbial methanogenesis is a known source of methane in marine systems. In most sediments, the majority of methanogenesis is located below the sulfate-reducing zone, as sulfate reducers outcompete methanogens for the major substrates hydrogen and acetate. The coexistence of methanogenesis and sulfate reduction has been shown before and is possible through the usage of noncompetitive substrates by methanogens such as methanol or methylated amines. However, knowledge about the magnitude, seasonality, and environmental controls of this noncompetitive methane production is sparse. In the present study, the presence of methanogenesis within the sulfate reduction zone (SRZ methanogenesis) was investigated in sediments (0-30 cm below seafloor, cm b.s.f.) of the seasonally hypoxic Eckernförde Bay in the southwestern Baltic Sea. Water column parameters such as oxygen, temperature, and salinity together with porewater geochemistry and benthic methanogenesis rates were determined in the sampling area Boknis Eck quarterly from March 2013 to September 2014 to investigate the effect of seasonal environmental changes on the rate and distribution of SRZ methanogenesis, to estimate its potential contribution to benthic methane emissions, and to identify the potential methanogenic groups responsible for SRZ methanogenesis. The metabolic pathway of methanogenesis in the presence or absence of sulfate reducers, which after the addition of a noncompetitive substrate was studied in four experimental setups: (1) unaltered sediment batch incubations (net methanogenesis), (2) 14C-bicarbonate labeling experiments (hydrogenotrophic methanogenesis), (3) manipulated experiments with the addition of either molybdate (sulfate reducer inhibitor), 2-bromoethanesulfonate (methanogen inhibitor), or methanol (noncompetitive substrate, potential methanogenesis), and (4) the addition of 13C-labeled methanol (potential methylotrophic methanogenesis). After incubation with methanol, molecular

  8. Long-term effects of increasing acidity on low-pH sulfate-reducing bioprocess and bacterial community.

    Science.gov (United States)

    Zhao, Jing; Fang, Di; Zhang, Pengfei; Zhou, Lixiang

    2017-02-01

    An ethanol-fed, sulfate-reducing anaerobic baffled reactor was operated over a period of 260 days to assess the effects of sequentially more acidic conditions (pH 4.5-2.5) on sulfate reduction and bacterial community. Results showed that the reactor could reduce sulfate and generate alkalinity at progressively lower pH values of 4.5, 3.5, and 2.5 in a synthetic wastewater containing 2500 mg/L sulfate. About 93.9% of the influent sulfate was removed at a rate of 4691 mg/L/day, and the effluent pH was increased to 6.8 even when challenged with influent pH as low as 2.5. Illumina MiSeq sequencing revealed that a step decrease in influent pH from 4.5 to 2.5 resulted in noticeable decrease in the biodiversity inside the sulfidogenic reactor. Additionally, complete and incomplete organic oxidizers Desulfobacter and Desulfovibrio were observed to be the most dominant sulfate reducers at pH 2.5, sustaining the low-pH, high-rate sulfate removal and alkalinity generation.

  9. Desulfosporosinus acididurans sp. nov.: an acidophilic sulfate-reducing bacterium isolated from acidic sediments

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Stams, A.J.M.; Hedrich, S.; Nancucheo, I.; Johnson, D.B.

    2015-01-01

    Three strains of sulfate-reducing bacteria (M1T, D, and E) were isolated from acidic sediments (White river and Tinto river) and characterized phylogenetically and physiologically. All three strains were obligately anaerobic, mesophilic, spore-forming straight rods, stained Gram-negative and

  10. Effect of hydraulic retention time on metal precipitation in sulfate reducing inverse fluidized bed reactors

    KAUST Repository

    Villa-Gómez, Denys Kristalia

    2014-02-13

    BACKGROUND: Metal sulfide recovery in sulfate reducing bioreactors is a challenge due to the formation of small precipitates with poor settling properties. The size of the metal sulfide precipitates with the change in operational parameters such as pH, sulfide concentration and reactor configuration has been previously studied. The effect of the hydraulic retention time (HRT) on the metal precipitate characteristics such as particle size for settling has not yet been addressed. RESULTS: The change in size of the metal (Cu, Zn, Pb and Cd) sulfide precipitates as a function of the HRT was studied in two sulfate reducing inversed fluidized bed (IFB) reactors operating at different chemical oxygen demand concentrations to produce high and low sulfide concentrations. The decrease of the HRT from 24 to 9h in both IFB reactors affected the contact time of the precipitates formed, thus making differences in aggregation and particle growth regardless of the differences in sulfide concentration. Further HRT decrease to 4.5h affected the sulfate reducing activity for sulfide production and hence, the supersaturation level and solid phase speciation. Metal sulfide precipitates affected the sulfate reducing activity and community in the biofilm, probably because of the stronger local supersaturation causing metal sulfides accumulation in the biofilm. CONCLUSIONS: This study shows that the HRT is an important factor determining the size and thus the settling rate of the metal sulfides formed in bioreactors.

  11. Diversity, activity, and abundance of sulfate-reducing bacteria in saline nad hypersaline soda lakes

    NARCIS (Netherlands)

    Foti, M.; Sorokin, D.Y.; Lomans, B.P.; Mussman, M.; Zacharova, E.E.; Pimenov, N.V.; Kuenen, J.G.; Muyzer, G.

    2007-01-01

    Soda lakes are naturally occurring highly alkaline and saline environments. Although the sulfur cycle is one of the most active element cycles in these lakes, little is known about the sulfate-reducing bacteria (SRB). In this study we investigated the diversity, activity, and abundance of SRB in

  12. Enrichment and isolation of acidophilic sulfate-reducing bacteria from Tinto River sediments

    NARCIS (Netherlands)

    Sanchez-Andrea, I.; Stams, A.J.M.; Amils, R.; Sanz, J.L.

    2013-01-01

    Although some acidophilic and alkaliphilic species have been described recently, most of the known sulfate-reducing bacteria (SRB) grow optimally at neutral pH. In this study, sulfate reduction was studied with sediment samples from the extremely acidic Tinto River basin. Stable enrichments of SRB

  13. Depth distribution and assembly of sulfate-reducing microbial communities in marine sediments of Aarhus Bay

    DEFF Research Database (Denmark)

    Jochum, Lara M; Chen, Xihan; Lever, Mark A

    2017-01-01

    Most sulfate-reducing microorganisms (SRM) present in subsurface marine sediments belong to uncultured groups only distantly related to known SRM and it remains unclear how changing geochemical zones and sediment depth influence their community structure. We mapped the community composition and a...

  14. Effect of bioaugmentation and biostimulation on sulfate-reducing column startup captured by functional gene profiling.

    Science.gov (United States)

    Pereyra, Luciana P; Hiibel, Sage R; Perrault, Elizabeth M; Reardon, Kenneth F; Pruden, Amy

    2012-10-01

    Sulfate-reducing permeable reactive zones (SR-PRZs) depend upon a complex microbial community to utilize a lignocellulosic substrate and produce sulfides, which remediate mine drainage by binding heavy metals. To gain insight into the impact of the microbial community composition on the startup time and pseudo-steady-state performance, functional genes corresponding to cellulose-degrading (CD), fermentative, sulfate-reducing, and methanogenic microorganisms were characterized in columns simulating SR-PRZs using quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE). Duplicate columns were bioaugmented with sulfate-reducing or CD bacteria or biostimulated with ethanol or carboxymethyl cellulose and compared with baseline dairy manure inoculum and uninoculated controls. Sulfate removal began after ~ 15 days for all columns and pseudo-steady state was achieved by Day 30. Despite similar performance, DGGE profiles of 16S rRNA gene and functional genes at pseudo-steady state were distinct among the column treatments, suggesting the potential to control ultimate microbial community composition via bioaugmentation and biostimulation. qPCR revealed enrichment of functional genes in all columns between the initial and pseudo-steady-state time points. This is the first functional gene-based study of CD, fermentative and sulfate-reducing bacteria and methanogenic archaea in a lignocellulose-based environment and provides new qualitative and quantitative insight into startup of a complex microbial system. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  15. Mechanisms and Effectivity of Sulfate Reducing Bioreactors Using a Chitinous Substrate in Treating Mining Influenced Water

    Science.gov (United States)

    Mining-influenced water (MIW) is the main environmental challenges associated with the mining industry. Passive MIW remediation can be achieved through microbial activity in sulfate-reducing bioreactors (SRBRs), but their actual removal rates depend on different factors, one of w...

  16. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

    NARCIS (Netherlands)

    Villa Gomez, D.K.; Cassidy, J.; Keesman, K.J.; Sampaio, R.M.; Lens, P.N.L.

    2014-01-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4 2- ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing

  17. Sulfate-reducing bacteria and their activities in cyanobacterial mats of Solar Lake (Sinai, Egypt)

    DEFF Research Database (Denmark)

    Teske, A.; Ramsing, NB; Habicht, K.

    1998-01-01

    The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 10(6) and 10(7) cultivable sulfate...

  18. Microbial Activity In The Peerless Jenny King Sulfate Reducing Bioreactors System

    Science.gov (United States)

    The Peerless Jenny King treatment system is a series of four sulfate reducing bioreactor cells installed to treat acid mine drainage in the Upper Tenmile Creek Superfund Site located in the Rimini Mining District, near Helena, MT. The system consists of a wetland pretreatment fo...

  19. DESIGNING SULFATE-REDUCING BACTERIA FIELD-BIOREACTORS USING THE BEST MODEL

    Science.gov (United States)

    DESIGNING SULFATE-REDUCING BACTERIA FIELD-BIOREACTORS USING THE BEST MODELMarek H. Zaluski1,3, Brian T. Park1, Diana R. Bless21 MSE Technology Applications; 200 Technology Way, Butte, Montana 59701, USA2 U.S. EPA, Office of Research and Development, Cincinna...

  20. Electron-bifurcating transhydrogenase is central to hydrogen isotope fractionation during lipid biosynthesis in sulfate reducing bacteria

    Science.gov (United States)

    Leavitt, W.; Flynn, T. M.; Suess, M.; Bradley, A. S.

    2015-12-01

    A significant range in microbial lipid 2H/1H ratios is observed in modern marine sediments [Li et al. 2009. GCA]. The magnitude of hydrogen isotope fractionation between microbial lipids and growth water (2ɛlipid-H2O) is hypothesized to relate to the central carbon and energy metabolism [Zhang et al. 2009. PNAS]. These observations have raised the intriguing possibility for culture independent identification of the dominant metabolic pathways operating in environments critical to the geological record. One such metabolism we would like to track for its global significance in sedimentary carbon cycling is bacterial sulfate reduction [Jørgensen. 1982. Nature]. To-date, heterotrophic sulfate reducing bacteria (SRB) have been observed to produce lipids that are depleted in fatty acid H-isotope composition, relative to growth water (2ɛlipid-H2O ~ -125 to -175 ‰), with experiments on different substrates yielding little variability [Campbell et al. 2009. GCA; Osburn. 2013; Dawson et al. 2015. Geobiology]. In stark contrast, aerobic heterotrophs show a wide range in fractionations (2ɛlipid-H2O ~ +300 to -125‰) which seems to scale with the route cellular carbon metabolism [Zhang et al. 2009. PNAS; Heinzelmann et al. 2015. Front Microbio]. Recent work in aerobic methylotrophs [Bradley et al. 2014. AGU] implicates transhydrogenase (TH) activity as a critical control on 2ɛlipid-H2O. This work suggests a specific driving mechanism for this range in fractionation is the ratio of intracellular NADPH/NADH, and more fundamentally, the intracellular redox state. In SRB a key component of energy metabolism is the activity of electron-bifurcating TH [Price et al. 2014. Front Microbio], for which a recent transposon mutant library has generated a number of knockouts in the target gene [Kuehl et al. 2014. mBio] in the model organism Desulfovibrio alaskensis strain G20. In this study we compare growth rates, fatty acid concentrations and 2ɛlipid-H2O from wild type and TH

  1. Sulfate-reducing bacteria colonize pouches formed for ulcerative colitis but not for familial adenomatous polyposis.

    LENUS (Irish Health Repository)

    Duffy, M

    2012-02-03

    PURPOSE: Ileal pouch-anal anastomosis remains the "gold standard" in surgical treatment of ulcerative colitis and familial adenomatous polyposis. Pouchitis occurs mainly in patients with a background of ulcerative colitis, although the reasons for this are unknown. The aim of this study was to characterize differences in pouch bacterial populations between ulcerative colitis and familial adenomatous pouches. METHODS: After ethical approval was obtained, fresh stool samples were collected from patients with ulcerative colitis pouches (n = 10), familial adenomatous polyposis (n = 7) pouches, and ulcerative colitis ileostomies (n = 8). Quantitative measurements of aerobic and anaerobic bacteria were performed. RESULTS: Sulfate-reducing bacteria were isolated from 80 percent (n = 8) of ulcerative colitis pouches. Sulfate-reducing bacteria were absent from familial adenomatous polyposis pouches and also from ulcerative colitis ileostomy effluent. Pouch Lactobacilli, Bifidobacterium, Bacteroides sp, and Clostridium perfringens counts were increased relative to ileostomy counts in patients with ulcerative colitis. Total pouch enterococci and coliform counts were also increased relative to ileostomy levels. There were no significant quantitative or qualitative differences between pouch types when these bacteria were evaluated. CONCLUSIONS: Sulfate-reducing bacteria are exclusive to patients with a background of ulcerative colitis. Not all ulcerative colitis pouches harbor sulfate-reducing bacteria because two ulcerative colitis pouches in this study were free of the latter. They are not present in familial adenomatous polyposis pouches or in ileostomy effluent collected from patients with ulcerative colitis. Total bacterial counts increase in ulcerative colitis pouches after stoma closure. Levels of Lactobacilli, Bifidobacterium, Bacteroides sp, Clostridium perfringens, enterococci, and coliforms were similar in both pouch groups. Because sulfate-reducing bacteria are

  2. Mobilization of arsenic on nano-TiO2 in soil columns with sulfate reducing bacteria.

    Science.gov (United States)

    Luo, Ting; Ye, Li; Chan, Tingshan; Jing, Chuanyong

    2017-12-12

    Arsenic (As) remediation in contaminated water using nanoparticles is promising. However, the fate and transport of As associated with nano-adsorbents in natural environment is poorly understood. To investigate the fate of adsorbed As on nano-TiO2 in changed redox condition from oxic to anoxic, we added the As(V)-TiO2 suspension in groundwater to an autoclaved soil column which inoculated a sulfate-reducing bacterium, Desulfovibrio vulgaris DP4. The dissolved As(V) in effluent increased to 798 μg/L for the biotic column and to 1510 μg/L for the abiotic control, and dissolved As(III) was observed only in biotic column. The total As (dissolved plus particulate) in the biotic column effluent (high to 2.5 mg/L) was substantially higher than the abiotic control (1.5 mg/L). Therefore SRB restrained the release of dissolved As, and facilitated the transport of particulate As. Micro-XRF analysis suggested that the nano-TiO2 with As was mainly retained in the influent front and that its transport was negligible. Our pe-pH calculation and XANES analysis demonstrated that generated secondary iron minerals containing magnetite and mackinawite mainly were responsible for dissolved As retention, and then transported with As as particulate As. The results shed light on the mobilization of adsorbed As on a nano-adsorbent in an anoxic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

    Directory of Open Access Journals (Sweden)

    Jackson Z Lee

    2014-02-01

    Full Text Available Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB. However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S, and intertidal Lyngbya microbial mats (GN-I -- were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of dsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and nanoSIMS (secondary ion mass-spectrometry indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi.

  4. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A., E-mail: jimfield@email.arizona.edu

    2016-05-05

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  5. Purification and characterization of a surfactin-like molecule produced by Bacillus sp. H2O-1 and its antagonistic effect against sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    Korenblum Elisa

    2012-11-01

    Full Text Available Abstract Background Bacillus sp. H2O-1, isolated from the connate water of a Brazilian reservoir, produces an antimicrobial substance (denoted as AMS H2O-1 that is active against sulfate reducing bacteria, which are the major bacterial group responsible for biogenic souring and biocorrosion in petroleum reservoirs. Thus, the use of AMS H2O-1 for sulfate reducing bacteria control in the petroleum industry is a promising alternative to chemical biocides. However, prior to the large-scale production of AMS H2O-1 for industrial applications, its chemical structure must be elucidated. This study also analyzed the changes in the wetting properties of different surfaces conditioned with AMS H2O-1 and demonstrated the effect of AMS H2O-1 on sulfate reducing bacteria cells. Results A lipopeptide mixture from AMS H2O-1 was partially purified on a silica gel column and identified via mass spectrometry (ESI-MS. It comprises four major components that range in size from 1007 to 1049 Da. The lipid moiety contains linear and branched β-hydroxy fatty acids that range in length from C13 to C16. The peptide moiety contains seven amino acids identified as Glu-Leu-Leu-Val-Asp-Leu-Leu. Transmission electron microscopy revealed cell membrane alteration of sulfate reducing bacteria after AMS H2O-1 treatment at the minimum inhibitory concentration (5 μg/ml. Cytoplasmic electron dense inclusions were observed in treated cells but not in untreated cells. AMS H2O-1 enhanced the osmosis of sulfate reducing bacteria cells and caused the leakage of the intracellular contents. In addition, contact angle measurements indicated that different surfaces conditioned by AMS H2O-1 were less hydrophobic and more electron-donor than untreated surfaces. Conclusion AMS H2O-1 is a mixture of four surfactin-like homologues, and its biocidal activity and surfactant properties suggest that this compound may be a good candidate for sulfate reducing bacteria control. Thus, it is a potential

  6. Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins

    OpenAIRE

    Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

    2014-01-01

    Background The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. Results In this study, a draft genome sequence of D. biacutus ...

  7. The Importance of Sulfate Adenylyl Transferase in S and O Fractionation by Sulfate Reducing Bacteria

    Science.gov (United States)

    Smith, D. A.; Johnston, D. T.; Bradley, A. S.

    2016-12-01

    Microbial sulfate reduction (MSR) is critical to the oxidation of organic matter in modern and ancient oceans, and plays an important role in regulating the redox state of the Earth's surface. The sulfur and oxygen isotopic composition of seawater sulfate and of sulfate minerals reflect the biogeochemical processes that cycle sulfur, of which MSR is among the most important. MSR is a multi-enzymatic reaction network that partitions the isotopes of sulfur and oxygen as a consequence of both the flux of sulfate through this biochemical network and the fractionation imposed by each individual enzyme. MSR affects the δ18O of residual, extracellular sulfate mainly by the equilibration of the MSR intermediate sulfite with extracellular water (Antler et al., 2013 GCA, Wankel et al., 2013 Geobiol). A series of oxidative and exchange reactions catalyzed by APS reductase (APSr), sulfate adenylyl transferase (Sat), and sulfate transporters promote the conversion of water-equilibrated intracellular sulfite to extracellular sulfate. The flux of sulfoxy anions via these proteins will be, at least in part, dependent on the activity of these enzymes. To test this, we examined sulfur and oxygen isotope fractionation in genetically engineered mutants of the sulfate reducing bacterium Desulfovibrio vulgaris Hildenborough (DvH). In these mutants, the activity of Sat has been artificially increased by perturbing the (i) transcriptional repressor Rex and (ii) its binding site upstream of the gene encoding Sat (Christensen et al., 2015 J. Bacteriol). It was predicted that this would minimize the back reaction of Sat, enhance the intracellular pool of APS, and minimize the equilibration between sulfite and adenosine monophosphate (AMP). Both mutants, along with the wild type DvH were grown in batch culture made with water enriched in 18O. Samples were collected throughout batch growth, and we report the evolution of the S and O isotopic composition of sulfate, and of the S isotopic

  8. Uranium immobilization by sulfate-reducing biofilms grown on hematite, dolomite, and calcite.

    Science.gov (United States)

    Marsili, Enrico; Beyenal, Haluk; Di Palma, Luca; Merli, Carlo; Dohnalkova, Alice; Amonette, James E; Lewandowski, Zbigniew

    2007-12-15

    Biofilms of sulfate-reducing bacteria Desulfovibrio desulfuricans G20 were used to reduce dissolved U(VI) and subsequently immobilize U(IV) in the presence of uranium-complexing carbonates. The biofilms were grown in three identically operated fixed bed reactors, filled with three types of minerals: one noncarbonate-bearing mineral (hematite) and two carbonate-bearing minerals (calcite and dolomite). The source of carbonates in the reactors filled with calcite and dolomite were the minerals, while in the reactor filled with hematite it was a 10 mM carbonate buffer, pH 7.2, which we added to the growth medium. Our five-month study demonstrated that the sulfate-reducing biofilms grown in all reactors were able to immobilize/reduce uranium efficiently, despite the presence of uranium-complexing carbonates.

  9. Diversity of methanogens and sulfate-reducing bacteria in the interfaces of five deep-sea anoxic brines of the Red Sea

    KAUST Repository

    Guan, Yue

    2015-11-01

    Oceanic deep hypersaline anoxic basins (DHABs) are characterized by drastic changes in physico-chemical conditions in the transition from overlaying seawater to brine body. Brine-seawater interfaces (BSIs) of several DHABs across the Mediterranean Sea have been shown to possess methanogenic and sulfate-reducing activities, yet no systematic studies have been conducted to address the potential functional diversity of methanogenic and sulfate-reducing communities in the Red Sea DHABs. Here, we evaluated the relative abundance of Bacteria and Archaea using quantitative PCR and conducted phylogenetic analyses of nearly full-length 16S rRNA genes as well as functional marker genes encoding the alpha subunits of methyl-coenzyme M reductase (mcrA) and dissimilatory sulfite reductase (dsrA). Bacteria predominated over Archaea in most locations, the majority of which were affiliated with Deltaproteobacteria, while Thaumarchaeota were the most prevalent Archaea in all sampled locations. The upper convective layers of Atlantis II Deep, which bear increasingly harsh environmental conditions, were dominated by members of the class Thermoplasmata (Marine Benthic Group E and Mediterranean Sea Brine Lakes Group 1). Our study revealed unique microbial compositions, the presence of niche-specific groups, and collectively, a higher diversity of sulfate-reducing communities compared to methanogenic communities in all five studied locations. © 2015 Institut Pasteur.

  10. Development of Microarrays-Based Metagenomics Technology for Monitoring Sulfate-Reducing Bacteria in Subsurface Environments

    Energy Technology Data Exchange (ETDEWEB)

    Cindy, Shi

    2015-07-17

    At the contaminated DOE sites, sulfate-reducing bacteria (SRB) are a significant population and play an important role in the microbial community during biostimulation for metal reduction. However, the diversity, structure and dynamics of SRB communities are poorly understood. Therefore, this project aims to use high throughput sequencing-based metagenomics technologies for characterizing the diversity, structure, functions, and activities of SRB communities by developing genomic and bioinformatics tools to link the SRB biodiversity with ecosystem functioning.

  11. Characterization of sulfate-reducing granular sludge in the SANI(®) process.

    Science.gov (United States)

    Hao, Tianwei; Wei, Li; Lu, Hui; Chui, Hokwong; Mackey, Hamish R; van Loosdrecht, Mark C M; Chen, Guanghao

    2013-12-01

    Hong Kong practices seawater toilet flushing covering 80% of the population. A sulfur cycle-based biological nitrogen removal process, the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process, had been developed to close the loop between the hybrid water supply and saline sewage treatment. To enhance this novel process, granulation of a Sulfate-Reducing Up-flow Sludge Bed (SRUSB) reactor has recently been conducted for organic removal and provision of electron donors (sulfide) for subsequent autotrophic denitrification, with a view to minimizing footprint and maximizing operation resilience. This further study was focused on the biological and physicochemical characteristics of the granular sulfate-reducing sludge. A lab-scale SRUSB reactor seeded with anaerobic digester sludge was operated with synthetic saline sewage for 368 days. At 1 h nominal hydraulic retention time (HRT) and 6.4 kg COD/m(3)-d organic loading rate, the SRUSB reactor achieved 90% COD and 75% sulfate removal efficiencies. Granular sludge was observed within 30 days, and became stable after 4 months of operation with diameters of 400-500 μm, SVI5 of 30 ml/g, and extracellular polymeric substances of 23 mg carbohydrate/g VSS. Fluorescence in situ hybridization (FISH) analysis revealed that the granules were enriched with abundant sulfate-reducing bacteria (SRB) as compared with the seeding sludge. Pyrosequencing analysis of the 16S rRNA gene in the sulfate-reducing granules on day 90 indicated that the microbial community consisted of a diverse SRB genera, namely Desulfobulbus (18.1%), Desulfobacter (13.6%), Desulfomicrobium (5.6%), Desulfosarcina (0.73%) and Desulfovibrio (0.6%), accounting for 38.6% of total operational taxonomic units at genera level, with no methanogens detected. The microbial population and physicochemical properties of the granules well explained the excellent performance of the granular SRUSB reactor. Copyright © 2013 Elsevier

  12. Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins.

    Science.gov (United States)

    Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

    2014-07-11

    The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. In this study, a draft genome sequence of D. biacutus was established. Sequencing, assembly and annotation resulted in 159 contigs with 5,242,029 base pairs and 4773 predicted genes; 4708 were predicted protein-encoding genes, and 3520 of these had a functional prediction. Proteins and genes were identified that are specifically induced during growth with acetone. A thiamine diphosphate-requiring enzyme appeared to be highly induced during growth with acetone and is probably involved in the activation reaction. Moreover, a coenzyme B12- dependent enzyme and proteins that are involved in redox reactions were also induced during growth with acetone. We present for the first time the genome of a sulfate reducer that is able to grow with acetone. The genome information of this organism represents an important tool for the elucidation of a novel reaction mechanism that is employed by a sulfate reducer in acetone activation.

  13. Electron microscopic characterization of the sulfate reducer Desulfovibrio vulgaris: biofilms and clumps

    Science.gov (United States)

    Auer, M.; Remis, J.; Jorgens, D.; Zemla, M.; Singer, M.; Schmitt, J.; Gorby, Y.; Hazen, T.; Wall, J.; Elias, D.; Torok, T.

    2008-12-01

    Numerous studies have helped characterize the stress response of the anaerobic sulfate reducer Desulfovibrio vulgaris Hildenborough (DvH). Yet all of these techniques represent bulk analyses of cells grown mostly under liquid culture conditions in large reactors. Such results represent an average over a large variety of individual cellular responses, hence assuming a homogeneous distribution of physiological traits. Moreover, only recently are those techniques applied to the environmentally more relevant condition of microbial communities (biofilms). What is missing is a detailed ultrastructural analysis of such biofilms in order to determine biofilm organization and its extracellular metal deposition distribution. Using sophisticated sample cryo-preparation approaches such as high-pressure freezing, freeze-substitution or microwave- assisted processing, followed serial section TEM imaging, we have found a large heterogeneity with respect to metal precipitation with some cells being surrounded by metal precipitates whereas neighboring cells, being genetically identical and seeing virtually the exact same microenvironment, completely lack extracellular metal deposits. Interestingly, apart from metal deposits near cell surfaces, we also found string- and sheet- like metal deposits in between neighboring cells that in mature biofilms can extend for hundreds of micrometers. In mature DvH biofilms such deposits were predominantly associated with areas of intact cells in biofilms, with areas devoid of such metal deposits displayed predominantly cell debris, suggesting a role of such deposits for cell survival, which may be of high significance to biofilms at DOE sites. Upon tomographic imaging we found that extracellular metal deposits were often associated with thin filaments and vesicle-like features. To complement our serial section 2D analysis of resin-embedded samples and the resulting limitation of sampling 3D biofilm as thin sections of arbitrary orientation, we

  14. Tetrahydrofolate serves as a methyl acceptor in the demethylation of dimethylsulfoniopropionate in cell extracts of sulfate-reducing bacteria

    NARCIS (Netherlands)

    Jansen, M; Hansen, T.A.

    Tetrahydrofolate was shown to function as a methyl acceptor in the anaerobic demethylation of dimethylsulfoniopropionate to methylthiopropionate in cell extracts of the sulfate-reducing bacterium strain WN. Dimethylsulfoniopropionate-dependent activities were 0.56 mu mol methyltetrahydrofolate

  15. Diversity and Composition of Sulfate-Reducing Microbial Communities Based on Genomic DNA and RNA Transcription in Production Water of High Temperature and Corrosive Oil Reservoir

    Science.gov (United States)

    Li, Xiao-Xiao; Liu, Jin-Feng; Zhou, Lei; Mbadinga, Serge M.; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

    2017-01-01

    Deep subsurface petroleum reservoir ecosystems harbor a high diversity of microorganisms, and microbial influenced corrosion is a major problem for the petroleum industry. Here, we used high-throughput sequencing to explore the microbial communities based on genomic 16S rDNA and metabolically active 16S rRNA analyses of production water samples with different extents of corrosion from a high-temperature oil reservoir. Results showed that Desulfotignum and Roseovarius were the most abundant genera in both genomic and active bacterial communities of all the samples. Both genomic and active archaeal communities were mainly composed of Archaeoglobus and Methanolobus. Within both bacteria and archaea, the active and genomic communities were compositionally distinct from one another across the different oil wells (bacteria p = 0.002; archaea p = 0.01). In addition, the sulfate-reducing microorganisms (SRMs) were specifically assessed by Sanger sequencing of functional genes aprA and dsrA encoding the enzymes adenosine-5′-phosphosulfate reductase and dissimilatory sulfite reductase, respectively. Functional gene analysis indicated that potentially active Archaeoglobus, Desulfotignum, Desulfovibrio, and Thermodesulforhabdus were frequently detected, with Archaeoglobus as the most abundant and active sulfate-reducing group. Canonical correspondence analysis revealed that the SRM communities in petroleum reservoir system were closely related to pH of the production water and sulfate concentration. This study highlights the importance of distinguishing the metabolically active microorganisms from the genomic community and extends our knowledge on the active SRM communities in corrosive petroleum reservoirs. PMID:28638372

  16. Diversity and Composition of Sulfate-Reducing Microbial Communities Based on Genomic DNA and RNA Transcription in Production Water of High Temperature and Corrosive Oil Reservoir

    Directory of Open Access Journals (Sweden)

    Xiao-Xiao Li

    2017-06-01

    Full Text Available Deep subsurface petroleum reservoir ecosystems harbor a high diversity of microorganisms, and microbial influenced corrosion is a major problem for the petroleum industry. Here, we used high-throughput sequencing to explore the microbial communities based on genomic 16S rDNA and metabolically active 16S rRNA analyses of production water samples with different extents of corrosion from a high-temperature oil reservoir. Results showed that Desulfotignum and Roseovarius were the most abundant genera in both genomic and active bacterial communities of all the samples. Both genomic and active archaeal communities were mainly composed of Archaeoglobus and Methanolobus. Within both bacteria and archaea, the active and genomic communities were compositionally distinct from one another across the different oil wells (bacteria p = 0.002; archaea p = 0.01. In addition, the sulfate-reducing microorganisms (SRMs were specifically assessed by Sanger sequencing of functional genes aprA and dsrA encoding the enzymes adenosine-5′-phosphosulfate reductase and dissimilatory sulfite reductase, respectively. Functional gene analysis indicated that potentially active Archaeoglobus, Desulfotignum, Desulfovibrio, and Thermodesulforhabdus were frequently detected, with Archaeoglobus as the most abundant and active sulfate-reducing group. Canonical correspondence analysis revealed that the SRM communities in petroleum reservoir system were closely related to pH of the production water and sulfate concentration. This study highlights the importance of distinguishing the metabolically active microorganisms from the genomic community and extends our knowledge on the active SRM communities in corrosive petroleum reservoirs.

  17. Obligate sugar oxidation in Mesotoga spp., phylum Thermotogae, in the presence of either elemental sulfur or hydrogenotrophic sulfate-reducers as electron acceptor.

    Science.gov (United States)

    Fadhlaoui, Khaled; Ben Hania, Wagdi; Armougom, Fabrice; Bartoli, Manon; Fardeau, Marie-Laure; Erauso, Gaël; Brasseur, Gaël; Aubert, Corinne; Hamdi, Moktar; Brochier-Armanet, Céline; Dolla, Alain; Ollivier, Bernard

    2018-01-01

    Mesotoga prima strain PhosAc3 is a mesophilic representative of the phylum Thermotogae comprising only fermentative bacteria so far. We show that while unable to ferment glucose, this bacterium is able to couple its oxidation to reduction of elemental sulfur. We demonstrate furthermore that M. prima strain PhosAc3 as well as M. prima strain MesG1 and Mesotoga infera are able to grow in syntrophic association with sulfate-reducing bacteria (SRB) acting as hydrogen scavengers through interspecies hydrogen transfer. Hydrogen production was higher in M. prima strain PhosAc3 cells co-cultured with SRB than in cells cultured alone in the presence of elemental sulfur. We propose that the efficient sugar-oxidizing metabolism by M. prima strain PhosAc3 in syntrophic association with a hydrogenotrophic sulfate-reducing bacterium can be extrapolated to all members of the Mesotoga genus. Genome comparison of Thermotogae members suggests that the metabolic difference between Mesotoga and Thermotoga species (sugar oxidation versus fermentation) is mainly due to the absence of the bifurcating [FeFe]-hydrogenase in the former. Such an obligate oxidative process for using sugars, unusual within prokaryotes, is the first reported within the Thermotogae. It is hypothesized to be of primary ecological importance for growth of Mesotoga spp. in the environments that they inhabit. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Microbial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian margin

    Science.gov (United States)

    Maltby, J.; Sommer, S.; Dale, A. W.; Treude, T.

    2016-01-01

    We studied the concurrence of methanogenesis and sulfate reduction in surface sediments (0-25 cm below sea floor) at six stations (70, 145, 253, 407, 990 and 1024 m) along the Peruvian margin (12° S). This oceanographic region is characterized by high carbon export to the seafloor creating an extensive oxygen minimum zone (OMZ) on the shelf, both factors that could favor surface methanogenesis. Sediments sampled along the depth transect traversed areas of anoxic and oxic conditions in the bottom-near water. Net methane production (batch incubations) and sulfate reduction (35S-sulfate radiotracer incubation) were determined in the upper 0-25 cm b.s.f. of multiple cores from all stations, while deep hydrogenotrophic methanogenesis (> 30 cm b.s.f., 14C-bicarbonate radiotracer incubation) was determined in two gravity cores at selected sites (78 and 407 m). Furthermore, stimulation (methanol addition) and inhibition (molybdate addition) experiments were carried out to investigate the relationship between sulfate reduction and methanogenesis.Highest rates of methanogenesis and sulfate reduction in the surface sediments, integrated over 0-25 cm b.s.f., were observed on the shelf (70-253 m, 0.06-0.1 and 0.5-4.7 mmol m-2 d-1, respectively), while lowest rates were discovered at the deepest site (1024 m, 0.03 and 0.2 mmol m-2 d-1, respectively). The addition of methanol resulted in significantly higher surface methanogenesis activity, suggesting that the process was mostly based on non-competitive substrates - i.e., substrates not used by sulfate reducers. In the deeper sediment horizons, where competition was probably relieved due to the decrease of sulfate, the usage of competitive substrates was confirmed by the detection of hydrogenotrophic activity in the sulfate-depleted zone at the shallow shelf station (70 m).Surface methanogenesis appeared to be correlated to the availability of labile organic matter (C / N ratio) and organic carbon degradation (DIC production

  19. Activity and phylogenetic diversity of sulfate-reducing microorganisms in low-temperature subsurface fluids within the upper oceanic crust

    Directory of Open Access Journals (Sweden)

    Alberto eRobador

    2015-01-01

    Full Text Available The basaltic ocean crust is the largest aquifer system on Earth, yet the rates of biological activity in this environment are unknown. Low-temperature (<100 °C fluid samples were investigated from two borehole observatories in the Juan de Fuca Ridge flank, representing a range of upper oceanic basement thermal and geochemical properties. Microbial sulfate reduction rates were measured in laboratory incubations with 35S-sulfate over a range of temperatures, with microbial activity limited by the availability of organic electron donors. Thermodynamic calculations indicate energetic constraints for metabolism in the higher temperature, more altered and isolated fluids, which together with relatively higher cell-specific sulfate reduction rates reveal increased maintenance requirements, consistent with novel species-level dsrAB phylotypes of thermophilic sulfate-reducing microorganisms. Our estimates suggest that microbially-mediated sulfate reduction may account for the removal of organic matter in fluids within the upper oceanic crust and underscore the potential quantitative impact of microbial processes in deep subsurface marine crustal fluids on marine and global biogeochemical carbon cycling.

  20. Apparent Minimum Free Energy Requirements for Methanogenic Archaea and Sulfate-Reducing Bacteria in an Anoxic Marine Sediment

    Science.gov (United States)

    Hoehler, Tori M.; Alperin, Marc J.; Albert, Daniel B.; Martens, Christopher S.; DeVincenzi, Don (Technical Monitor)

    2000-01-01

    Among the most fundamental constraints governing the distribution of microorganisms in the environment is the availability of chemical energy at biologically useful levels. To assess the minimum free energy yield that can support microbial metabolism in situ, we examined the thermodynamics of H2-consuming processes in anoxic sediments from Cape Lookout Bight, NC, USA. Depth distributions of H2 partial pressure, along with a suite of relevant concentration data, were determined in sediment cores collected in November (at 14.5 C) and August (at 27 C) and used to calculate free energy yields for methanogenesis and sulfate reduction. At both times of year, and for both processes, free energy yields gradually decreased (became less negative) with depth before reaching an apparent asymptote. Sulfate reducing bacteria exhibited an asymptote of -19.1 +/- 1.7 kj(mol SO4(2-)(sup -1) while methanogenic archaea were apparently supported by energy yields as small as -10.6 +/- 0.7 kj(mol CH4)(sup -1).

  1. Molecular analysis of the spatio-temporal distribution of sulfate-reducing bacteria (SRB) in Camargue (France) hypersaline microbial mat.

    Science.gov (United States)

    Fourçans, Aude; Ranchou-Peyruse, Anthony; Caumette, Pierre; Duran, Robert

    2008-07-01

    The spatio-temporal distribution of sulfate-reducing bacteria (SRB) in the microbial mat of Camargue (Salins-de-Giraud, France) was investigated by molecular approaches at both microscale spatial resolution and different taxonomic organization levels. The vertical distribution of the SRB populations was correlated with oxygen and sulfide microgradient fluctuations. Comparisons of Terminal restriction fragment length polymorphism (T-RFLP) fingerprints showed distinct locations of some operational taxonomic units at daytime and at night (4:00 or 15:00 hours) revealing important differences on the structures of the bacterial communities. When oxygen penetrates the mat, SRB migration was observed either downward to reach deeper anoxic zones to escape oxygen or upward to reach oxic surface zones. When no migration was observed, both metabolism switches and aggregate formations were suspected. These behaviors allowed the aerotolerant SRB to deal with oxygen. The analysis of the Desulfococcus-Desulfonema-Desulfosarcina T-RFLP profiles revealed up-migrating populations related to both Desulfonema sp. and Desulfosarcina variabilis. T-RFLP profiles combined with 16S ribosomal ribonucleic acid gene library analysis of the Desulfobacter group revealed two distinct populations: a population related to the recently described Desulfotignum genus migrating upward during the night and a population of a new species of the Desulfobacter uniformly located throughout the mat independent of the period. Thus, the identification of the new oxygen-tolerant SRB will provide the basis for understanding the physiological adaptations to oxygen.

  2. BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

    Science.gov (United States)

    SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

    1963-06-01

    Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

  3. Interface-mediated synthesis of monodisperse ZnS nanoparticles with sulfate-reducing bacterium culture.

    Science.gov (United States)

    Liang, Zhanguo; Mu, Jun; Mu, Ying; Shi, Jiaming; Hao, Wenjing; Dong, Xuewei; Yu, Hongquan

    2013-12-01

    We have created a new method of ZnS nanospheres synthesis. By interface-mediated precipitation method (IMPM), monodisperse ZnS nanoparticles was synthesized on the particle surface of sulfate-reducing bacterium nutritious agar culture. Sulfate-reducing bacterium (SRB) was used as a sulfide producer because of its dissimilatory sulfate reduction capability, meanwhile produced a variety of amino acids acting as templates for nanomaterials synthesis. Then zinc acetate was dispersed into nutritious agar plate. Subsequently agar plate was broken into particles bearing much external surface, which successfully mediated the synthesis of monodisperse ZnS nanoparticles. The morphology of monodisperse ZnS nanospheres and SRB were examined by scanning electron microscopy (SEM), and the microstructure was investigated by X-ray diffraction (XRD). The thermostability of ZnS nanoparticles was determined by thermo gravimetric-differential thermo gravimetric (TG-DTG). The maximum absorption wavelengh was analysed with an ultraviolet-visible spectrophotometer within a range of 199-700 nm. As a result, monodisperse ZnS nanoparticles were successfully synthesized, with an average diameter of 80 nm. Maximum absorption wavelengh was 228 nm, and heat decomposed temperature of monodisperse ZnS nanoparticles was 596°C. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  4. Anaerobic consortia of fungi and sulfate reducing bacteria in deep granite fractures.

    Science.gov (United States)

    Drake, Henrik; Ivarsson, Magnus; Bengtson, Stefan; Heim, Christine; Siljeström, Sandra; Whitehouse, Martin J; Broman, Curt; Belivanova, Veneta; Åström, Mats E

    2017-07-04

    The deep biosphere is one of the least understood ecosystems on Earth. Although most microbiological studies in this system have focused on prokaryotes and neglected microeukaryotes, recent discoveries have revealed existence of fossil and active fungi in marine sediments and sub-seafloor basalts, with proposed importance for the subsurface energy cycle. However, studies of fungi in deep continental crystalline rocks are surprisingly few. Consequently, the characteristics and processes of fungi and fungus-prokaryote interactions in this vast environment remain enigmatic. Here we report the first findings of partly organically preserved and partly mineralized fungi at great depth in fractured crystalline rock (-740 m). Based on environmental parameters and mineralogy the fungi are interpreted as anaerobic. Synchrotron-based techniques and stable isotope microanalysis confirm a coupling between the fungi and sulfate reducing bacteria. The cryptoendolithic fungi have significantly weathered neighboring zeolite crystals and thus have implications for storage of toxic wastes using zeolite barriers.Deep subsurface microorganisms play an important role in nutrient cycling, yet little is known about deep continental fungal communities. Here, the authors show organically preserved and partly mineralized fungi at 740 m depth, and find evidence of an anaerobic fungi and sulfate reducing bacteria consortium.

  5. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors.

    Science.gov (United States)

    Villa-Gomez, D K; Cassidy, J; Keesman, K J; Sampaio, R; Lens, P N L

    2014-03-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4(2-) ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing bioreactors. The sulfide was measured using a sulfide ion selective electrode (pS) and the values obtained were used to calculate proportional-integral-derivative (PID) controller parameters. The experiments were performed in an inverse fluidized bed bioreactor with automated operation using the LabVIEW software version 2009(®). A rapid response and high sulfide increment was obtained through a stepwise increase in the CODin concentration, while a stepwise decrease to the HRT exhibited a slower response with smaller sulfide increment. Irrespective of the way the OLR was decreased, the pS response showed a time-varying behavior due to sulfide accumulation (HRT change) or utilization of substrate sources that were not accounted for (CODin change). The pS electrode response, however, showed to be informative for applications in sulfate reducing bioreactors. Nevertheless, the recorded pS values need to be corrected for pH variations and high sulfide concentrations (>200 mg/L). Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. The first genomic and proteomic characterization of a deep-sea sulfate reducer: insights into the piezophilic lifestyle of Desulfovibrio piezophilus.

    Directory of Open Access Journals (Sweden)

    Nathalie Pradel

    Full Text Available Desulfovibrio piezophilus strain C1TLV30(T is a piezophilic anaerobe that was isolated from wood falls in the Mediterranean deep-sea. D. piezophilus represents a unique model for studying the adaptation of sulfate-reducing bacteria to hydrostatic pressure. Here, we report the 3.6 Mbp genome sequence of this piezophilic bacterium. An analysis of the genome revealed the presence of seven genomic islands as well as gene clusters that are most likely linked to life at a high hydrostatic pressure. Comparative genomics and differential proteomics identified the transport of solutes and amino acids as well as amino acid metabolism as major cellular processes for the adaptation of this bacterium to hydrostatic pressure. In addition, the proteome profiles showed that the abundance of key enzymes that are involved in sulfate reduction was dependent on hydrostatic pressure. A comparative analysis of orthologs from the non-piezophilic marine bacterium D. salexigens and D. piezophilus identified aspartic acid, glutamic acid, lysine, asparagine, serine and tyrosine as the amino acids preferentially replaced by arginine, histidine, alanine and threonine in the piezophilic strain. This work reveals the adaptation strategies developed by a sulfate reducer to a deep-sea lifestyle.

  7. Sulfate-reducing bacteria are common members of bacterial communities in Altamira Cave (Spain).

    Science.gov (United States)

    Portillo, M Carmen; Gonzalez, Juan M

    2009-01-15

    The conservation of paleolithic paintings such as those in Altamira Cave (Spain) is a primary objective. Recent molecular studies have shown the existence of unknown microbial communities in this cave including anaerobic microorganisms on cave walls. Herein, we analyzed an anaerobic microbial group, the sulfate-reducing bacteria (SRB), from Altamira Cave with potential negative effects on painting conservation. In the present work, the communities of bacteria and SRB were studied through PCR-DGGE analysis. Data suggest that SRB communities represent a significant, highly diverse bacterial group in Altamira Cave. These findings represent a first report on this physiological group on caves with paleolithic paintings and their potential biodegradation consequences. Expanding our knowledge on microbial communities in Altamira Cave is a priority to design appropriate conservation strategies.

  8. Sulfate Reducing Bacteria as Bio-cleaning Agents: Development of New Methodologies and Study Cases

    Directory of Open Access Journals (Sweden)

    Annalisa Balloi

    2017-06-01

    Full Text Available In the last decades, the contribution of different scientific disciplines in the field of restoration and conservation of cultural heritage to finding alternative methods of investigation that are even more effective and fully respect artworks, operators and environment, has greatly increased.An example is the University of Milan patent that provides for the use of some specialized bacteria as cleaning agents. This method, known as biocleaning, is based on the use of Desulfovibrio vulgaris, a sulfate reducing bacterium, for the removal of sulfate alterations from stone surfaces.Recently, the university spin-off Micro4yoU purchased the patent by initiating a series of investments aimed at enhancing the commercial product from prototype. The present work describes: the desulfation mechanism operated by Desulfovibrio vulgaris and the technological shift necessary to obtain a biological formulation usable in situ, with two practical case studies.

  9. Corrosion inhibition of stainless steel by a sulfate-reducing bacteria biofilm in seawater

    Science.gov (United States)

    Li, Fu-shao; An, Mao-zhong; Duan, Dong-xia

    2012-08-01

    Corrosion inhibition of stainless steel due to a sulfate-reducing bacteria (SRB) biofilm in seawater was studied. By atomic force microscopy, a layer of fish-scale-like biofilm was found to form as stainless steel coupons were exposed to the culture media with SRB, and this biofilm grew more and more compact. As a result, coupons' surface under the biofilm turned irregular less slowly than that exposed to the sterilized culture media. Then, physicoelectric characteristics of the electrode/biofilm/solution interface were investigated by electrochemical impedance spectroscopy (EIS), and the coverage of the biofilm as well as the relative irregularity of coupons' surface was also recorded by EIS spectra. Finally, anodic cyclic polarization results further demonstrated the protective property of the biofilm. Therefore, in estimation of SRB-implicated corrosion of stainless steel, not only the detrimental SRB metabolites but also the protective SRB biofilm as well should be taken into account.

  10. Sulfate reducing bacteria as secondary and necessary pathogens in black band disease of corals

    Directory of Open Access Journals (Sweden)

    Abigael C. Brownell

    2014-09-01

    Full Text Available Black band disease (BBD is a complex, polymicrobial disease that consists of cyanobacteria, sulfide-oxidizing and sulfate-reducing bacteria (SRB, and heterotrophic bacteria. The cyanobacterium Roseofilum reptotaenium has been implicated as the primary pathogen of BBD, but other consortium members may be secondary pathogens that are necessary to the development of the disease. It is known that populations of the sulfate-reducing bacterium Desulfovibrio are present in BBD and that these populations generate sulfide within the band as a byproduct of dissimilatory sulfate reduction. It is also known that exposure of healthy corals to sulfide leads to cell lysis and coral tissue death. Previous work showed that when freshly collected BBD, which easily infects healthy corals, is exposed to sodium molybdate, a specific inhibitor of sulfate reduction, infection does not occur. In this study we examined the effect of sodium molybdate on infection of corals by a unialgal culture of R. reptotaenium. Coral fragments of Montastraea cavernosa and Siderastrea siderea were transferred into two experimental aquaria, one a control with only artificial seawater (ASW and the second containing ASW and 2mM sodium molybdate. Small mats of cultured R. reptotaenium were inoculated onto the surface of experimental coral fragments. Both M. cavernosa (n = 6 and S. siderea (n=4 became infected and developed BBD-like infections in the control tank, while there were temporary attachments to, but no successful infection of M. cavernosa (n=3 or S. siderea (n=2 in the experimental tank containing sodium molybdate. The results of this study reveal that a secondary pathogen is essential to the infection process and development of BBD in scleractinian corals. Specifically, SRB such as Desulfovibrio are required for the development of BBD on the coral host. This is the first step in understanding the roles of secondary pathogens in a complex, polymicrobial coral disease.

  11. Immobilization of cobalt by sulfate-reducing bacteria in subsurface sediments

    Science.gov (United States)

    Krumholz, Lee R.; Elias, Dwayne A.; Suflita, Joseph M.

    2003-01-01

    We investigated the impact of sulfate-reduction on immobilization of metals in subsurface aquifers. Co 2+ was used as a model for heavy metals. Factors limiting sulfate-reduction dependent Co 2+ immobilization were tested on pure cultures of sulfate-reducing bacteria, and in sediment columns from a landfill leachate contaminated aquifer. In the presence of 1 mM Co 2+ , the growth of pure cultures of sulfate-reducing bacteria was not impacted. Cultures of Desulfovibrio desulfuricans, Desulfotomaculum gibsoniae , and Desulfomicrobium hypogeia removed greater than 99.99% of the soluble Co 2+ when CoCl 2 was used with no chelators. The above cultures and Desulfoarcula baarsi removed 98-99.94% of the soluble Co(II) when the metal was complexed with the model ligand nitrilotriacetate (Co-NTA). Factors controlling the rate of sulfate-reduction based Co 2+ precipitation were investigated in sediment-cobalt mixtures. Several electron donors were tested and all but toluene accelerated soluble Co 2+ loss. Ethanol and formate showed the greatest stimulation. All complex nitrogen sources tested slowed and decreased the extent of Co 2+ removal from solution relative to formate-amended sediment incubations. A range of pH values were tested (6.35-7.81), with the more alkaline incubations exhibiting the largest precipitation of Co 2+ . The immobilization of Co 2+ in sediments was also investigated with cores to monitor the flow of Co 2+ through undisturbed sediments. An increase in the amount of Co 2+ immobilized as CoS was observed as sulfate reduction activity was stimulated in flow through columns. Both pure culture and sediment incubation data indicate that stimulation of sulfate reduction is a viable strategy in the immobilization of contaminating metals in subsurface systems.

  12. Comparison of sulfate-reducing and conventional Anammox upflow anaerobic sludge blanket reactors.

    Science.gov (United States)

    Rikmann, Ergo; Zekker, Ivar; Tomingas, Martin; Vabamäe, Priit; Kroon, Kristel; Saluste, Alar; Tenno, Taavo; Menert, Anne; Loorits, Liis; Rubin, Sergio S C dC; Tenno, Toomas

    2014-10-01

    Autotrophic NH4(+) removal has been extensively researched, but few studies have investigated alternative electron acceptors (for example, SO4(2-)) in NH4(+) oxidation. In this study, sulfate-reducing anaerobic ammonium oxidation (SRAO) and conventional Anammox were started up in upflow anaerobic sludge blanket reactors (UASBRs) at 36 (±0.5)°C and 20 (±0.5)°C respectively, using reject water as a source of NH4(+). SO4(2-) or NO2(-), respectively, were applied as electron acceptors. It was assumed that higher temperature could promote the SRAO, partly compensating its thermodynamic disadvantage comparing with the conventional Anammox to achieve comparable total nitrogen (TN) removal rate. Average volumetric NH4(+)-N removal rate in the sulfate-reducing UASBR1 was however 5-6 times less (0.03 kg-N/(m(3) day)) than in the UASBR2 performing conventional nitrite-dependent autotrophic nitrogen removal (0.17 kg-N/(m(3) day)). However, the stoichiometric ratio of NH4(+) removal in UASBR1 was significantly higher than could be expected from the extent of SO4(2-) reduction, possibly due to interactions between the N- and S-compounds and organic matter of the reject water. Injections of N2H4 and NH2OH accelerated the SRAO. Similar effect was observed in batch tests with anthraquinone-2,6-disulfonate (AQDS). For detection of key microorganisms PCR-DGGE was used. From both UASBRs, uncultured bacterium clone ATB-KS-1929 belonging to the order Verrucomicrobiales, Anammox bacteria (uncultured Planctomycete clone Pla_PO55-9) and aerobic ammonium-oxidizing bacteria (uncultured sludge bacterium clone ASB08 "Nitrosomonas") were detected. Nevertheless the SRAO process was shown to be less effective for the treatment of reject water, compared to the conventional Anammox. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov

    2006-01-01

    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  14. Effects of Spartina alterniflora invasion on the communities of methanogens and sulfate-reducing bacteria in estuarine marsh sediments

    Directory of Open Access Journals (Sweden)

    Jemaneh eZeleke

    2013-08-01

    Full Text Available The effect of plant invasion on the microorganisms of soil sediments is very important for estuary ecology. The community structures of methanogens and sulfate-reducing bacteria (SRB as a function of Spartina alterniflora invasion in Phragmites australis-vegetated sediments of the Dongtan wetland in the Yangtze River estuary, China, were investigated using 454 pyrosequencing and quantitative real-time PCR (qPCR of the methyl coenzyme M reductase A (mcrA and dissimilatory sulfite-reductase (dsrB genes. Sediment samples were collected from two replicate locations, and each location included three sampling stands each covered by monocultures of P. australis, S. alterniflora and both plants (transition stands, respectively. qPCR analysis revealed higher copy numbers of mcrA genes in sediments from S. alterniflora stands than P. australis stands (5- and 7.5-fold more in the spring and summer, respectively, which is consistent with the higher methane flux rates measured in the S. alterniflora stands (up to 8.01 ± 5.61 mg m-2 h-1. Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens. Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands. In contrast, insignificant variations were observed in the diversity of SRB with the invasion. Although Methanomicrobiales and Methanococcales, the hydrogenotrophic methanogens, dominated in the salt marsh, Methanomicrobiales displayed a slight increase with the invasion and growth of S. alterniflora, whereas the later responded differently. Methanosarcina, the metabolically diverse methanogens, did not vary with the invasion of, but Methanosaeta, the exclusive acetate utilizers, appeared to increase with S. alterniflora invasion. In SRB, sequences closely related to the families Desulfobacteraceae and Desulfobulbaceae dominated in the salt marsh, although they displayed minimal changes with the S

  15. Sulfate-reducing bacteria in marine sediment (Aarhus Bay, Denmark): abundance and diversity related to geochemical zonation.

    Science.gov (United States)

    Leloup, Julie; Fossing, Henrik; Kohls, Katharina; Holmkvist, Lars; Borowski, Christian; Jørgensen, Bo Barker

    2009-05-01

    In order to better understand the main factors that influence the distribution of sulfate-reducing bacteria (SRB), their population size and their metabolic activity in high- and low-sulfate zones, we studied the SRB diversity in 3- to 5-m-deep sediment cores, which comprised the entire sulfate reduction zone and the upper methanogenic zone. By combining EMA (ethidium monoazide that can only enter damaged/dead cells and may also bind to free DNA) treatment with real-time PCR, we determined the distributions of total intact bacteria (16S rDNA genes) and intact SRB (dsrAB gene), their relative population sizes, and the proportion of dead cells or free DNA with depth. The abundance of SRB corresponded in average to 13% of the total bacterial community in the sulfate zone, 22% in the sulfate-methane transition zone and 8% in the methane zone. Compared with the total bacterial community, there were relatively less dead/damaged cells and free DNA present than among the SRB and this fraction did not change systematically with depth. By DGGE analysis, based on the amplification of the dsrA gene (400 bp), we found that the richness of SRB did not change with depth through the geochemical zones; but the clustering was related to the chemical zonation. A full-length clone library of the dsrAB gene (1900 bp) was constructed from four different depths (20, 110, 280 and 500 cm), and showed that the dsrAB genes in the near-surface sediment (20 cm) was mainly composed of sequences close to the Desulfobacteraceae, including marine complete and incomplete oxidizers such as Desulfosarcina, Desulfobacterium and Desulfococcus. The three other libraries were predominantly composed of Gram-positive SRB.

  16. Sulfate-reducing bacteria release barium and radium from naturally occurring radioactive material in oil-field barite

    Science.gov (United States)

    Phillips, E.J.P.; Landa, E.R.; Kraemer, T.; Zielinski, R.

    2001-01-01

    Scale and sludge deposits formed during oil production can contain elevated levels of Ra, often coprecipitated with barium sulfate (barite). The potential for sulfate-reducing bacteria to release 226 Ra and Ba (a Ra analog) from oil-field barite was evaluated. The concentration of dissolved Ba increased when samples containing pipe scale, tank sludge, or oil-field brine pond sediment were incubated with sulfate-reducing bacteria Desulfovibrio sp., Str LZKI, isolated from an oil-field brine pond. However, Ba release was not stoichiometric with sulfide production in oil-field samples, and sulfate-reducing activity was predictable from the amount of Ba released. As with Ba, only a fraction of the 226Ra expected from the amount of sulfide produced was released, and most of the Ra remained associated with the solid material.

  17. Metabolic network modularity in archaea depends on growth conditions.

    Science.gov (United States)

    Takemoto, Kazuhiro; Borjigin, Suritalatu

    2011-01-01

    Network modularity is an important structural feature in metabolic networks. A previous study suggested that the variability in natural habitat promotes metabolic network modularity in bacteria. However, since many factors influence the structure of the metabolic network, this phenomenon might be limited and there may be other explanations for the change in metabolic network modularity. Therefore, we focus on archaea because they belong to another domain of prokaryotes and show variability in growth conditions (e.g., trophic requirement and optimal growth temperature), but not in habitats because of their specialized growth conditions (e.g., high growth temperature). The relationship between biological features and metabolic network modularity is examined in detail. We first show the absence of a relationship between network modularity and habitat variability in archaea, as archaeal habitats are more limited than bacterial habitats. Although this finding implies the need for further studies regarding the differences in network modularity, it does not contradict previous work. Further investigations reveal alternative explanations. Specifically, growth conditions, trophic requirement, and optimal growth temperature, in particular, affect metabolic network modularity. We have discussed the mechanisms for the growth condition-dependant changes in network modularity. Our findings suggest different explanations for the changes in network modularity and provide new insights into adaptation and evolution in metabolic networks, despite several limitations of data analysis.

  18. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong; Yu, Tong, E-mail: tong.yu@ualberta.ca; Liu, Yang, E-mail: yang.liu@ualberta.ca

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H{sub 2}S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. - Graphical abstract: The development of sulfate reducing bacteria (SRB) within Oil Sands Process-affected Water (OSPW) biofilm and the biofilm treatment of OSPW were evaluated by Liu and coworkers. Combined microsensor and molecular biology techniques were utilized in this study. Their results demonstrated that multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. - Highlights: • Biofilm in oil sands wastewater was developed on engineered biocarriers. • Bacterial community and in situ activity of SRB were studied in the

  19. Diversity and abundance of sulfate-reducing microorganisms in the sulfate and methane zones of a marine sediment, Black Sea RID A-8182-2008

    DEFF Research Database (Denmark)

    Leloup, Julie; Loy, Alexander; Knab, Nina J.

    2007-01-01

    branching sequences which might represent Gram-positive spore-forming sulfate- and/or sulfite-reducing microorganisms. We thus hypothesize that terminal carbon mineralization in surface sediments of the Black Sea is largely due to the sulfate reduction activity of previously hidden SRM. Although these novel......The Black Sea, with its highly sulfidic water column, is the largest anoxic basin in the world. Within its sediments, the mineralization of organic matter occurs essentially through sulfate reduction and methanogenesis. In this study, the sulfate-reducing community was investigated in order...... SRM were also abundant in sulfate-poor, methanogenic areas of the Black Sea sediment, their activities and possibly very versatile metabolic capabilities remain subject of further study....

  20. Comparison between sodium hypochlorite and copper sulfate reducer in lightening of overexposed working length radiographs

    Directory of Open Access Journals (Sweden)

    Fatemeh Ezoddini Ardakani

    2015-12-01

    Full Text Available Objectives: The aims of this study were to test whether lightening of the overexposed radiographs improve determination of endodontic files length and whether lightened radiographs are comparable with ideally exposed radiographs. Material and Methods: Four dried human skull coated with soft tissue-equivalent wax used for exposing radiographs of the upper molars. First, the endodontic file was placed in full length of the root and four series of radiographs obtained. The time to expose the first series was unchanged (standard group but increased for the other three series.  Two series of overexposed radiographs set as test groups (one lightened with copper sulfate reducer and the other lightened with sodium hypochlorite and one series set as control group. Then the endodontic file placed 2mm short in the root and four series of radiographs obtained like the former. A viewer evaluated radiographs. ROC curves were obtained and areas under the curves were calculated. Sensitivity, specificity and Cohen’s kappa was calculated. Results: The average area under ROC curves was 1, 0.995,1 and 0.643 for the standard, Copper sulfate, sodium hypochlorite and the control group, respectively. Sodium hypochlorite show a better performance in terms of sensitivity and specificity compared to Copper sulfate. Differences between the test radiographs and standard and control radiographs were significant (p

  1. Component analysis and heavy metal adsorption ability of extracellular polymeric substances (EPS) from sulfate reducing bacteria.

    Science.gov (United States)

    Yue, Zheng-Bo; Li, Qing; Li, Chuan-chuan; Chen, Tian-hu; Wang, Jin

    2015-10-01

    Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS. Potentiometric titration results indicated that the acidic constants (pKa) of the EPS fell into three ranges of 3.5-4.0, 5.9-6.7, and 8.9-9.8. The adsorption site concentrations of the surface functional groups also increased. Adsorption results suggested that EPS had a specific binding affinity for the dosed heavy metal, and that EPS extracted from the Zn(2+)-dosed system had a higher binding affinity for all heavy metals. Additionally, Zn(2+) decreased the inhibitory effects of Cd(2+) and Cu(2+) on the SRB. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Polysulfide reduction using sulfate-reducing bacteria in a photocatalytic hydrogen generation system.

    Science.gov (United States)

    Takahashi, Yui; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi

    2008-09-01

    A hydrogen generation process using photocatalytic reactions has been proposed. In this process, hydrogen sulfide is a source of hydrogen and is turned into polysulfide. In order to establish the cyclic operation of a photocatalytic hydrogen generation system, it is necessary to convert polysulfide back into hydrogen sulfide with a small energy input. This paper proposes the use of sulfate-reducing bacteria (SRB) for the regeneration of hydrogen sulfide. Batch cultivation of natural source SRB samples were carried out using a culture medium containing polysulfide as the only sulfur compound source. SRB produced hydrogen sulfide from several kinds of polysulfide sources, including a photocatalytic hydrogen generation-produces solution. Production lag phase and production rate of hydrogen sulfide were affected by initial polysulfide concentration. SRB activity was inhibited at high initial polysulfide concentrations. SRB enrichment culture T2, exhibited the highest hydrogen sulfide production rate, and was able to utilize several kinds of organic matter as the electron donor. The results suggest the possibility of using large biomass sources, such as sewage sludge and the raw garbage in a hydrogen generation system. We developed speculative estimates that an SRB based hydrogen generation system is feasible.

  3. Sulfate-reducing bacteria stimulate gut immune responses and contribute to inflammation in experimental colitis.

    Science.gov (United States)

    Figliuolo, Vanessa Ribeiro; Dos Santos, Liliane Martins; Abalo, Alessandra; Nanini, Hayandra; Santos, Angela; Brittes, Nilda M; Bernardazzi, Claudio; de Souza, Heitor Siffert Pereira; Vieira, Leda Quercia; Coutinho-Silva, Robson; Coutinho, Claudia Mara Lara Melo

    2017-11-15

    The intestinal microbiota is critical for mammalian immune system development and homeostasis. Sulfate-reducing bacteria (SRB) are part of the normal gut microbiota, but their increased levels may contribute to colitis development, likely in association with hydrogen sulfide (H2S) production. Here, we investigated the effects of SRB in the gut immune response in germ-free mice, and in experimental colitis. After 7days of colonization with Desulfovibrio indonesiensis or with a human SRB consortium (from patients with colitis), germ-free mice exhibited alterations in the colonic architecture, with increased cell infiltration in the lamina propria. SRB colonization upregulated the Th17 and Treg profiles of cytokine production/cell activation, in T cells from mesenteric lymph nodes. These alterations were more pronounced in mice colonized with the human SRB consortium, although D. indonesiensis colonization produced higher levels of H2S. Importantly, the colon of C57BL/6 mice with colitis induced by TNBS or oxazolone had increased SRB colonization, and the administration of D. indonesiensis to mice with TNBS-induced colitis clearly exacerbated the alterations in colonic architecture observed in the established disease, and also increased mouse weight loss. We conclude that SRB contribute to immune response activation in the gut and play an important role in colitis development. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Bioremediation of copper-containing wastewater by sulfate reducing bacteria coupled with iron.

    Science.gov (United States)

    Bai, He; Kang, Yong; Quan, Hongen; Han, Yang; Sun, Jiao; Feng, Ying

    2013-11-15

    In order to treat copper-containing wastewater effectively using sulfate reducing bacteria (SRB), iron (Fe(0)) was added to enhance the activity of SRB. The SRB system and the SRB + Fe(0) system were operated under continuous operation. The sulfate reduction efficiency of the SRB + Fe(0) system was twice as much as that of the SRB system with the sulfate loading rate at 125  mg L(-1) h(-1). The effect of COD/SO4(2-) on sulfate reduction indicates an enhanced activity of SRB by adding Fe(0). 99% of total sulfate was deducted in both systems at pH 4.0-7.0, and temperature slightly influenced the removal of sulfate in the SRB + Fe(0) system. In the copper-containing wastewater treatment, the SRB + Fe(0) system shows a better performance since sulfate removal in this system was higher than the SRB system, and the removal ratio of Cu(2+) was held above 95% in SRB + Fe(0) system at all influent Cu(2+) concentrations. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  5. Inhibitory concentrations of 2,4D and its possible intermediates in sulfate reducing biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Cruz, Ulises [Department of Biotechnology, Environmental Science and Technology, Universidad Autonoma Metropolitana-Iztapalapa, Ave. San Rafael Atlixco 186, Vicentina, 09340 D.F. (Mexico); Celis, Lourdes B. [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Lomas 4a. Seccion, 78216 San Luis Potosi, S.L.P. (Mexico); Poggi, Hector [Department of Biotechnology and Bioengineering, CINVESTAV, Av. Instituto Politecnico Nacional 2508, Col. San Pedro Zacatenco, 07360 D.F. (Mexico); Meraz, Monica, E-mail: meraz@xanum.uam.mx [Department of Biotechnology, Environmental Science and Technology, Universidad Autonoma Metropolitana-Iztapalapa, Ave. San Rafael Atlixco 186, Vicentina, 09340 D.F. (Mexico)

    2010-07-15

    Different concentrations of the herbicide 2,4-dichlorophenoxyacetic acid (2,4D) and its possible intermediates such as 2,4-dichlorophenol (2,4DCP), 4-chlorophenol (4CP), 2-chlorophenol (2CP) and phenol, were assayed to evaluate the inhibitory effect on sulfate and ethanol utilization in a sulfate reducing biofilm. Increasing concentrations of the chlorophenolic compounds showed an adverse effect on sulfate reduction rate and ethanol conversion to acetate, being the intermediate 2,4DCP most toxic than the herbicide. The monochlorophenol 4CP (600 ppm) caused the complete cessation of sulfate reduction and ethanol conversion. The ratio of the electron acceptor to the electron donor utilized as well as the sulfate utilization volumetric rates, diminished when chlorophenols and phenol concentrations were increased, pointing out to the inhibition of the respiratory process and electrons transfer. The difference found in the IC{sub 50} values obtained was due to the chemical structure complexity of the phenolic compounds, the number of chlorine atoms as much as the chlorine atom position in the phenol ring. The IC{sub 50} values (ppm) indicated that the acute inhibition on the biofilm was caused by 2,4DCP (17.4) followed by 2,4D (29.0), 2CP (99.8), 4CP (108.0) and phenol (143.8).

  6. Sulfur Isotope Fractionation during the Evolutionary Adaptation of a Sulfate-Reducing Bacterium

    Science.gov (United States)

    Anderson-Trocmé, Luke; Whyte, Lyle G.; Zane, Grant M.; Wall, Judy D.; Wing, Boswell A.

    2015-01-01

    Dissimilatory sulfate reduction is a microbial catabolic pathway that preferentially processes less massive sulfur isotopes relative to their heavier counterparts. This sulfur isotope fractionation is recorded in ancient sedimentary rocks and generally is considered to reflect a phenotypic response to environmental variations rather than to evolutionary adaptation. Modern sulfate-reducing microorganisms isolated from similar environments can exhibit a wide range of sulfur isotope fractionations, suggesting that adaptive processes influence the sulfur isotope phenotype. To date, the relationship between evolutionary adaptation and isotopic phenotypes has not been explored. We addressed this by studying the covariation of fitness, sulfur isotope fractionation, and growth characteristics in Desulfovibrio vulgaris Hildenborough in a microbial evolution experiment. After 560 generations, the mean fitness of the evolved lineages relative to the starting isogenic population had increased by ∼17%. After 927 generations, the mean fitness relative to the initial ancestral population had increased by ∼20%. Growth rate in exponential phase increased during the course of the experiment, suggesting that this was a primary influence behind the fitness increases. Consistent changes were observed within different selection intervals between fractionation and fitness. Fitness changes were associated with changes in exponential growth rate but changes in fractionation were not. Instead, they appeared to be a response to changes in the parameters that govern growth rate: yield and cell-specific sulfate respiration rate. We hypothesize that cell-specific sulfate respiration rate, in particular, provides a bridge that allows physiological controls on fractionation to cross over to the adaptive realm. PMID:25662968

  7. Cathodic protection of XL 52 steel under the influence of sulfate reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, R. Garcia [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas No. 152, Col. San Bartolo Atepehuacan, Mexico, D.F. 07730 (Mexico); Departamento de lngenieria Metalurgica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Olivares, G. Zavala; Gayosso, M.J. Hernandez; Trejo, A. Gayosso [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas No. 152, Col. San Bartolo Atepehuacan, Mexico, D.F. 07730 (Mexico)

    2011-01-15

    The effect of sulfate reducing bacteria (SRB) upon the cathodic protection of XL 52 steel was determined, in order to identify if the potential value of -0.950 V versus copper/copper sulfate electrode is good enough to protect the metal surface. During the experiments, different operational parameters were monitored: hydrogen sulfide production, iron concentration, electrolyte alkalinity, microorganisms' population, as well as the metal surface damage. At the same time, the corrosion rate was determined using two electrochemical techniques: polarization resistance (PR) and electrochemical impedance spectroscopy (EIS). According to the results, it was observed that the protection potential of -0.950 V versus copper/copper sulfate electrode is not enough to control the microbiologically induced corrosion. This situation is reinforced by the fact that significant iron concentration was found in the electrolyte. The microbiological activity is not affected by the protection potential. On the contrary, the population growth is slightly strengthened. The alkalinity generated by the applied potential did not stop the SRB growth. A type of localized corrosion was developed during the experiments with microorganisms, even when the protection potential was applied to the system. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Community structure, cellular rRNA content, and activity of sulfate-reducing bacteria in marine Arctic sediments

    DEFF Research Database (Denmark)

    Ravenschlag, K.; Sahm, K.; Knoblauch, C.

    2000-01-01

    The community structure of sulfate-reducing bacteria (SRB) of a marine Arctic sediment (Smeerenburg-fjorden, Svalbard) a-as characterized by both fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization by using group- and genus-specific 16S rRNA-targeted oligonucleotide probes...

  9. BIOREACTOR ECONOMICS, SIZE AND TIME OF OPERATION (BEST) COMPUTER SIMULATOR FOR DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS

    Science.gov (United States)

    BEST (bioreactor economics, size and time of operation) is an Excel™ spreadsheet-based model that is used in conjunction with the public domain geochemical modeling software, PHREEQCI. The BEST model is used in the design process of sulfate-reducing bacteria (SRB) field bioreacto...

  10. Enhanced biological stabilization of heavy metals in sediment using immobilized sulfate reducing bacteria beads with inner cohesive nutrient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin, E-mail: hgxlixin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Dai, Lihua; Zhang, Chang; Zeng, Guangming; Liu, Yunguo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zhou, Chen [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University (United States); Xu, Weihua; Wu, Youe; Tang, Xinquan; Liu, Wei; Lan, Shiming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2017-02-15

    Highlights: • Nutrient beads of immobilized SRB were more effective in transforming heavy metals into the more stable bound phases. • Inner cohesive nutrient effectively promoted the stabilization process of heavy metals. • The excellent removal efficiencies of Cu, Zn, Pb and Cd were 76.3%, 95.6%, 100% and 91.2%, respectively. • Easy to recycle and avoid secondary pollution. - Abstract: A series of experiments were conducted for treating heavy metals contaminated sediments sampled from Xiangjiang River, which combined polyvinyl alcohol (PVA) and immobilized sulfate reducing bacteria (SRB) into beads. The sodium lactate was served as the inner cohesive nutrient. Coupling the activity of the SRB with PVA, along with the porous structure and huge specific surface area, provided a convenient channel for the transmission of matter and protected the cells against the toxicity of metals. This paper systematically investigated the stability of Cu, Zn, Pb and Cd and its mechanisms. The results revealed the performance of leaching toxicity was lower and the removal efficiencies of Cu, Zn, Pb and Cd were 76.3%, 95.6%, 100% and 91.2%, respectively. Recycling experiments showed the beads could be reused 5 times with superbly efficiency. These results were also confirmed by continuous extraction at the optimal conditions. Furthermore, X-ray diffraction (XRD) and energy-dispersive spectra (EDS) analysis indicated the heavy metals could be transformed into stable crystal texture. The stabilization of heavy metals was attributed to the carbonyl and acyl amino groups. Results presented that immobilized bacteria with inner nutrient were potentially and practically applied to multi-heavy-metal-contamination sediment.

  11. The sulfate-reducing bacterium Desulfovibrio desulfuricans ND132 as a model for understanding bacterial mercury methylation

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, C C [Smithsonian Environmental Research Center, Edgewater, MD; Elias, Dwayne A [ORNL; Kucken, A M [University of Missouri, Columbia; Brown, Steven D [ORNL; Palumbo, Anthony Vito [ORNL; Wall, Judy D. [University of Missouri

    2010-01-01

    We propose the use of Desulfovibrio sp. ND132 as a model species for understanding the genetics and biochemistry of microbial Hg methylation. ND132 is a dissimilatory sulfate-reducing bacterium (DSRB) that exhibits exceptionally high rates of Hg methylation in culture, but is otherwise a characteristically typical Desulfovibrio strain. The full genome sequence of ND132 will be available soon. ND132 is very similar to other DSRB that are sequenced but do not methylate Hg, allowing comparison for potential methylation genes. Here, we describe the physiological characteristics of the strain, examine its MeHg production capability, and place the strain within the phylogeny of the Desulfovibrionales using 16S rRNA. We also examine Hg toxicity and the inducibility of MeHg production amongst the DSRB by comparing ND132 to non-methylating DSRB. The optimal growth medium for Hg methylation is pyruvate/fumarate, which supports strong respiratory growth without sulfide production. At moderate Hg concentrations (10 ng/ml), and using TiNTA as a reductant, ND132 methylates about 30% of added HgCl2 during batch culture growth on 40 mM pyruvate/fumarate. Under constant culture conditions, MeHg production is an exponential function of Hg concentration, probably reflecting Hg partitioning between aqueous and solid phases. To help understand how Hg is taken up by this organism, we examined the influence of a variety of small thiol-bearing ligands, as well as select amino acids, on methylation by D. desulfuricans ND132. All thiol bearing ligands tested affected methylation in similar ways, suggesting that Hg uptake by ND132 is not associated with uptake of a specific amino acid. To identify enzymes for the methylation activity, a genetic approach is being pursued. Conjugation from E. coli donors works well that allows the generation of a transposon library of random ND132 mutants. These mutants will be screened for affects on mercury methylation.

  12. Distribution, activities, and interactions of methanogens and sulfate-reducing prokaryotes in the Florida Everglades.

    Science.gov (United States)

    Bae, Hee-Sung; Holmes, M Elizabeth; Chanton, Jeffrey P; Reddy, K Ramesh; Ogram, Andrew

    2015-11-01

    To gain insight into the mechanisms controlling methanogenic pathways in the Florida Everglades, the distribution and functional activities of methanogens and sulfate-reducing prokaryotes (SRPs) were investigated in soils (0 to 2 or 0 to 4 cm depth) across the well-documented nutrient gradient in the water conservation areas (WCAs) caused by runoff from the adjacent Everglades Agricultural Area. The methyl coenzyme M reductase gene (mcrA) sequences that were retrieved from WCA-2A, an area with relatively high concentrations of SO4 (2-) (≥39 μM), indicated that methanogens inhabiting this area were broadly distributed within the orders Methanomicrobiales, Methanosarcinales, Methanocellales, Methanobacteriales, and Methanomassiliicoccales. In more than 3 years of monitoring, quantitative PCR (qPCR) using newly designed group-specific primers revealed that the hydrogenotrophic Methanomicrobiales were more numerous than the Methanosaetaceae obligatory acetotrophs in SO4 (2-)-rich areas of WCA-2A, while the Methanosaetaceae were dominant over the Methanomicrobiales in WCA-3A (with relatively low SO4 (2-) concentrations; ≤4 μM). qPCR of dsrB sequences also indicated that SRPs are present at greater numbers than methanogens in the WCAs. In an incubation study with WCA-2A soils, addition of MoO4 (2-) (a specific inhibitor of SRP activity) resulted in increased methane production rates, lower apparent fractionation factors [αapp; defined as (amount of δ(13)CO2 + 1,000)/(amount of δ(13)CH4 + 1,000)], and higher Methanosaetaceae mcrA transcript levels compared to those for the controls without MoO4 (2-). These results indicate that SRPs play crucial roles in controlling methanogenic pathways and in shaping the structures of methanogen assemblages as a function of position along the nutrient gradient. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Sulfate-reducing microorganisms in wetlands – fameless actors in carbon cycling and climate change

    Directory of Open Access Journals (Sweden)

    Michael ePester

    2012-02-01

    Full Text Available Freshwater wetlands are a major source of the greenhouse gas methane but at the same time can function as carbon sink. Their response to global warming and environmental pollution is one of the largest unknowns in the upcoming decades to centuries. In this review, we highlight the role of sulfate-reducing microorganisms (SRM in the intertwined element cycles of wetlands. Although regarded primarily as methanogenic environments, biogeochemical studies have revealed a previously hidden sulfur cycle in wetlands that can sustain rapid renewal of the small standing pools of sulfate. Thus, dissimilatory sulfate reduction, which frequently occurs at rates comparable to marine surface sediments, can contribute up to 36–50% to anaerobic carbon mineralization in these ecosystems. Since sulfate reduction is thermodynamically favored relative to fermentative processes and methanogenesis, it effectively decreases gross methane production thereby mitigating the flux of methane to the atmosphere. However, very little is known about wetland SRM. Molecular analyses using dsrAB [encoding subunit A and B of the dissimilatory (bisulfite reductase] as marker genes demonstrated that members of novel phylogenetic lineages, which are unrelated to recognized SRM, dominate dsrAB richness and, if tested, are also abundant among the dsrAB-containing wetland microbiota. These discoveries point towards the existence of so far unknown SRM that are an important part of the autochthonous wetland microbiota. In addition to these numerically dominant microorganisms, a recent stable isotope probing study of SRM in a German peatland indicated that rare biosphere members might be highly active in situ and have a considerable stake in wetland sulfate reduction. The hidden sulfur cycle in wetlands and the fact that wetland SRM are not well represented by described SRM species explains their so far neglected role as important actors in carbon cycling and climate change.

  14. Sulfate-reducing bacteria slow intestinal transit in a bismuth-reversible fashion in mice.

    Science.gov (United States)

    Ritz, N L; Lin, D M; Wilson, M R; Barton, L L; Lin, H C

    2017-01-01

    Hydrogen sulfide (H2 S) serves as a mammalian cell-derived gaseous neurotransmitter. The intestines are exposed to a second source of this gas by sulfate-reducing bacteria (SRB). Bismuth subsalicylate binds H2 S rendering it insoluble. The aim of this study was to test the hypothesis that SRB may slow intestinal transit in a bismuth-reversible fashion. Eighty mice were randomized to five groups consisting of Live SRB, Killed SRB, SRB+Bismuth, Bismuth, and Saline. Desulfovibrio vulgaris, a common strain of SRB, was administered by gavage at the dose of 1.0 × 10(9) cells along with rhodamine, a fluorescent dye. Intestinal transit was measured 50 minutes after gavage by euthanizing the animals, removing the small intestine between the pyloric sphincter and the ileocecal valve and visualizing the distribution of rhodamine across the intestine using an imaging system (IVIS, Perkin-Elmer). Intestinal transit (n=50) was compared using geometric center (1=minimal movement, 100=maximal movement). H2 S concentration (n=30) was also measured when small intestinal luminal content was allowed to generate this gas. The Live SRB group had slower intestinal transit as represented by a geometric center score of 40.2 ± 5.7 when compared to Saline: 73.6 ± 5.7, Killed SRB: 77.9 ± 6.9, SRB+Bismuth: 81.0 ± 2.0, and Bismuth: 73.3 ± 4.2 (Pfashion in mice. Our results demonstrate that intestinal transit is slowed by SRB and this effect could be abolished by H2 S-binding bismuth. © 2016 John Wiley & Sons Ltd.

  15. Changing Microspatial Patterns of Sulfate-Reducing Microorganisms (SRM during Cycling of Marine Stromatolite Mats

    Directory of Open Access Journals (Sweden)

    Alexandru I. Petrisor

    2014-01-01

    Full Text Available Microspatial arrangements of sulfate-reducing microorganisms (SRM in surface microbial mats (~1.5 mm forming open marine stromatolites were investigated. Previous research revealed three different mat types associated with these stromatolites, each with a unique petrographic signature. Here we focused on comparing “non-lithifying” (Type-1 and “lithifying” (Type-2 mats. Our results revealed three major trends: (1 Molecular typing using the dsrA probe revealed a shift in the SRM community composition between Type-1 and Type-2 mats. Fluorescence in-situ hybridization (FISH coupled to confocal scanning-laser microscopy (CSLM-based image analyses, and 35SO42−-silver foil patterns showed that SRM were present in surfaces of both mat types, but in significantly (p < 0.05 higher abundances in Type-2 mats. Over 85% of SRM cells in the top 0.5 mm of Type-2 mats were contained in a dense 130 µm thick horizontal layer comprised of clusters of varying sizes; (2 Microspatial mapping revealed that locations of SRM and CaCO3 precipitation were significantly correlated (p < 0.05; (3 Extracts from Type-2 mats contained acylhomoserine-lactones (C4- ,C6- ,oxo-C6,C7- ,C8- ,C10- ,C12- , C14-AHLs involved in cell-cell communication. Similar AHLs were produced by SRM mat-isolates. These trends suggest that development of a microspatially-organized SRM community is closely-associated with the hallmark transition of stromatolite surface mats from a non-lithifying to a lithifying state.

  16. Mo enrichment in black shale and reduction of molybdate by sulfate-reducing bacteria (SRB) (Invited)

    Science.gov (United States)

    Xu, H.; Barton, L. L.

    2010-12-01

    The Lower Cambrian Black shale in Zunyi area of Guizhou Province, Southern China contains significant amount of Mo, As, and sulfide minerals. Additionally, Mo and sulfides are closely associated with organic matter of kerogen. Transmission electron microscopy (TEM) results show pyrite micro-crystals and Mo-As-S-bearing carbon (kerogen). High-resolution TEM image shows that Mo-rich areas are Mo-sulfide (molybdenite) layers that form poorly crystalline structures in organic carbon matrix. X-ray energy-dispersive spectra (EDS) indicate composition from the pyrite and the Mo-rich area. The black shale is very unique because of its high Mo concentration. One possible mechanism for enriching Mo from paleo-seawater is the involvement of SRB. Molybdate is an essential trace element required by biological systems including the anaerobic sulfate-reducing bacteria (SRB); however, detrimental consequences may occur if molybdate is present in high concentrations in the environment. We followed the growth of Desulfovibrio gigas ATCC 19364, D. vulgaris Hildenborough, D. desulfuricans DSM 642, and D. desulfuricans DSM 27774 in media containing sub-lethal levels of molybdate and observed a red-brown color in the culture fluid. Spectral analysis of the culture fluid revealed absorption peaks at 467 nm, 395 nm and 314 nm and this color is proposed to be a molybdate-sulfide complex. Reduction of molybdate with the formation of molybdate disulfide occurs in the periplasm D. gigas and D. desulfuricans DSM 642. From these results we suggest that the occurrence of poorly crystalline Mo-sulfides in black shale may be a result from SRB reduction and selective enrichment of Mo in paleo-seawater. We suggest that similar SRB mechanism could cause the Mo enrichment in a ~ 2.5 billion years old late Archean McRae Shale, which is related to the great oxidation event of early earth atmosphere.

  17. Changing Microspatial Patterns of Sulfate-Reducing Microorganisms (SRM) during Cycling of Marine Stromatolite Mats

    Science.gov (United States)

    Petrisor, Alexandru I.; Szyjka, Sandra; Kawaguchi, Tomohiro; Visscher, Pieter T.; Norman, Robert Sean; Decho, Alan W.

    2014-01-01

    Microspatial arrangements of sulfate-reducing microorganisms (SRM) in surface microbial mats (~1.5 mm) forming open marine stromatolites were investigated. Previous research revealed three different mat types associated with these stromatolites, each with a unique petrographic signature. Here we focused on comparing “non-lithifying” (Type-1) and “lithifying” (Type-2) mats. Our results revealed three major trends: (1) Molecular typing using the dsrA probe revealed a shift in the SRM community composition between Type-1 and Type-2 mats. Fluorescence in-situ hybridization (FISH) coupled to confocal scanning-laser microscopy (CSLM)-based image analyses, and 35SO4 2−-silver foil patterns showed that SRM were present in surfaces of both mat types, but in significantly (p < 0.05) higher abundances in Type-2 mats. Over 85% of SRM cells in the top 0.5 mm of Type-2 mats were contained in a dense 130 μm thick horizontal layer comprised of clusters of varying sizes; (2) Microspatial mapping revealed that locations of SRM and CaCO3 precipitation were significantly correlated (p < 0.05); (3) Extracts from Type-2 mats contained acylhomoserine-lactones (C4-, C6-, oxo-C6 C7-, C8-, C10-, C12-, C14-AHLs) involved in cell-cell communication. Similar AHLs were produced by SRM mat-isolates. These trends suggest that development of a microspatially-organized SRM community is closely-associated with the hallmark transition of stromatolite surface mats from a non-lithifying to a lithifying state. PMID:24413754

  18. CHROMIUM(VI REDUCTION BY A MIXED CULTURE OF SULFATE REDUCING BACTERIA DEVELOPED IN COLUMN REACTOR

    Directory of Open Access Journals (Sweden)

    Cynthia Henny

    2008-03-01

    Full Text Available A lactate enriched mixed sulfate reducing bacteria (SRB culture was examined for the reduction of Cr(VI in a continuous flow system. The influent was mineral salts media added with lactate and sulfate with amounts of 8 and 6 mM respectively as electron donor and electron acceptor. The SRB culture was allowed to stabilize in the column before adding the Cr(VI to the influent. Chromium and sulfate reduction and lactate oxidation were examined by measuring the concentrations of Cr(Vl, sulfate and lactate in the influent and the effluent over time. The experiment was discontinued when Cr(VI concentration in the effiuent was breakthrough. In the absence of Cr(VI, sulfate was not completely reduced in the column, although lactate was completely oxidized and acetate as an intermediate product was not often detected. Almost all of Cr(VI loaded was reduced in the column seeded with the SRB culture at influent Cr(VI concentrations of 192,385 and769 mM. There was no significant Cr(VI loss in the control column, indicating that Cr(VI removal was due to the reduction of Cr(VI to Cr (lll by the SRB culture. The instantaneous Cr(VI removal decreased to a minimum of 32%, 24 days after the influent Cr(VI concentration was increased to 1540 mM, ancl sulfate removal efficiency decreased to a minimum of 17%. The SRB population in the column decreased 100 days after C(VI was added to the column. The total mass of Cr(VI reduced was approximately 878 mmol out of 881 mmol of Cr(Vl loaded in 116 days. The results clearly show that our developed SRB culture could reduced Cr(Vl considerably.

  19. Temperature-Dependent Alkyl Glycerol Ether Lipid Composition of Mesophilic and Thermophilic Sulfate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Arnauld Vinçon-Laugier

    2017-08-01

    Full Text Available The occurrence of non-isoprenoid alkyl glycerol ether lipids in Bacteria and natural environments is increasingly being reported and the specificity and diagenetic stability of these lipids make them powerful biomarkers for biogeochemical and environmental studies. Yet the environmental controls on the biosynthesis of these peculiar membrane lipids remain poorly documented. Here, the lipid content of two mesophilic (Desulfatibacillum aliphaticivorans and Desulfatibacillum alkenivorans and one thermophilic (Thermodesulfobacterium commune sulfate-reducing bacteria—whose membranes are mostly composed of ether lipids—was investigated as a function of growth temperature (20–40°C and 54–84°C, respectively. For all strains, the cellular lipid content was lower at sub- or supra-optimal growth temperature, but the relative proportions of dialkyl glycerols, monoalkyl glycerols and fatty acids remained remarkably stable whatever the growth temperature. Rather than changing the proportions of the different lipid classes, the three strains responded to temperature changes by modifying the average structural composition of the alkyl and acyl chains constitutive of their membrane lipids. Major adaptive mechanisms concerned modifications of the level of branching and of the proportions of the different methyl branched lipids. Specifically, an increase in temperature induced mesophilic strains to produce less dimethyl branched dialkyl glycerols and 10-methyl branched lipids relative to linear structures, and the thermophilic strain to decrease the proportion of anteiso relative to iso methyl branched compounds. These modifications were in agreement with a regulation of the membrane fluidity. In one mesophilic and the thermophilic strains, a modification of the growth temperature further induced changes in the relative proportions of sn-2 vs sn-1 monoalkyl glycerols, suggesting an unprecedented mechanism of homeoviscous adaptation in Bacteria. Strong

  20. Identification of Syntrophobacteraceae as major acetate-degrading sulfate reducing bacteria in Italian paddy soil.

    Science.gov (United States)

    Liu, Pengfei; Pommerenke, Bianca; Conrad, Ralf

    2018-01-01

    Methane is an important greenhouse gas and acetate is the most important intermediate (average 70%) of the carbon flow to CH4 in paddy fields. Sulfate (e.g., gypsum) application can reduce CH4 emissions up to 70%. However, the effect of gypsum application on acetate degradation and the microbial communities involved are unclear. Therefore, we studied acetate-dependent sulfate reduction in anoxic microcosms of Italian rice paddy soil, combining profiling of 16S rRNA and dissimilatory sulfite reductase (dsrB) genes and transcripts and rRNA based stable isotope probing (SIP) analysis. Methane production was completely inhibited by gypsum in the absence of exogenous acetate. Amended acetate (either 13 C labelled or non-labelled) was stoichiometrically coupled to sulfate reduction or CH4 production. With methyl fluoride in the presence of sulfate, added propionate and butyrate were incompletely oxidized to acetate, which transiently accumulated. After the depletion of propionate and butyrate the accumulated acetate was rapidly consumed. The relative abundance of dsrB and 16S rRNA genes and transcripts from Syntrophobacteraceae (Desulfovirga spp., Syntrophobacter spp. and unclassified Syntrophobacteraceae) increased upon addition of gypsum and acetate. Simultaneously, Syntrophobacteraceae affiliated species were significantly labelled with 13 C. In addition, minor groups like Desulforhabdus spp., Desulfobacca spp. and Desulfotomaculum spp. substantially incorporated 13 C into their nucleic acids. The relative abundance of Desulfovibrio spp. slightly increased upon gypsum amendments. However, 13 C labelling of Desulfovibrio spp. was only moderate. In summary, Syntrophobacteraceae affiliated species were identified as the major acetotrophic sulfate reducers (SRB) in Italian paddy soil. The identification of these SRB as dominant acetate degraders well explained the scenarios of competition between SRB and acetoclastic methanogens as observed in rice paddy soil. © 2017

  1. Lake metabolism scales with lake morphometry and catchment conditions

    DEFF Research Database (Denmark)

    Stæhr, Peter Anton; Båstrup-Spohr, Lars; Jensen, Kaj Sand

    2012-01-01

    We used a comparative data set for 25 lakes in Denmark sampled during summer to explore the influence of lake morphometry, catchment conditions, light availability and nutrient input on lake metabolism. We found that (1) gross primary production (GPP) and community respiration (R) decline with la...... in lake morphometry and catchment conditions when comparing metabolic responses of lakes to human impacts....... area, water depth and drainage ratio, and increase with algal biomass (Chl), dissolved organic carbon (DOC) and total phosphorus (TP); (2) all lakes, especially small with less incident light, and forest lakes with high DOC, have negative net ecosystem production (NEP

  2. Homology modeling of dissimilatory APS reductases (AprBA of sulfur-oxidizing and sulfate-reducing prokaryotes.

    Directory of Open Access Journals (Sweden)

    Birte Meyer

    Full Text Available BACKGROUND: The dissimilatory adenosine-5'-phosphosulfate (APS reductase (cofactors flavin adenine dinucleotide, FAD, and two [4Fe-4S] centers catalyzes the transformation of APS to sulfite and AMP in sulfate-reducing prokaryotes (SRP; in sulfur-oxidizing bacteria (SOB it has been suggested to operate in the reverse direction. Recently, the three-dimensional structure of the Archaeoglobus fulgidus enzyme has been determined in different catalytically relevant states providing insights into its reaction cycle. METHODOLOGY/PRINCIPAL FINDINGS: Full-length AprBA sequences from 20 phylogenetically distinct SRP and SOB species were used for homology modeling. In general, the average accuracy of the calculated models was sufficiently good to allow a structural and functional comparison between the beta- and alpha-subunit structures (78.8-99.3% and 89.5-96.8% of the AprB and AprA main chain atoms, respectively, had root mean square deviations below 1 A with respect to the template structures. Besides their overall conformity, the SRP- and SOB-derived models revealed the existence of individual adaptations at the electron-transferring AprB protein surface presumably resulting from docking to different electron donor/acceptor proteins. These structural alterations correlated with the protein phylogeny (three major phylogenetic lineages: (1 SRP including LGT-affected Archaeoglobi and SOB of Apr lineage II, (2 crenarchaeal SRP Caldivirga and Pyrobaculum, and (3 SOB of the distinct Apr lineage I and the presence of potential APS reductase-interacting redox complexes. The almost identical protein matrices surrounding both [4Fe-4S] clusters, the FAD cofactor, the active site channel and center within the AprB/A models of SRP and SOB point to a highly similar catalytic process of APS reduction/sulfite oxidation independent of the metabolism type the APS reductase is involved in and the species it has been originated from. CONCLUSIONS: Based on the comparative

  3. Dietary protein, physiological condition and metabolic amino acid utilisation

    NARCIS (Netherlands)

    Weijs, P.J.M.

    1993-01-01

    This thesis describes the investigated effects of the level of dietary protein intake and the physiological condition of the animal on the percental oxidation of leucine. This measure reflects which part of the free leucine pool was used for protein and energy metabolism. The employed

  4. Contribution to the study of the role of sulfate-reducing bacteria in bio-corrosion phenomenon; Contribution a l'etude du role des bacteries sulfato-reductrices dans les phenomenes de biocorrosion

    Energy Technology Data Exchange (ETDEWEB)

    Chatelus, C

    1987-11-15

    By their metabolic activities of hydrogen consumption and of sulfides production, the sulfate-reducing bacteria are the main bacteria responsible of the metallic corrosion phenomena in the absence of oxygen. A physiological and enzymatic study of some Desulfovibrio has contributed to the understanding of the role of these bacteria in the anaerobic bio-corrosion phenomena. Desulfovibrio (D.) vulgaris in organic medium, after having oxidized the lactate, consumes the hydrogen formed by the electrochemical reaction of iron dissolution. The Desulfovibrio can be responsible either of a corrosion by a direct contact with the metal in using the H{sub 2} layer formed at its surface, (bacteria are then adsorbed at the surface because of an iron sulfide crystalline lattice), or of a distant corrosion in consuming the dissolved or gaseous hydrogen. As their hydrogenases can be stable in time independently of the cellular structure (D. vulparis) and active at high temperatures (to 70 C - 75 C) (D. baculatus), these bacteria can act in conditions incompatible with the viability of cells but compatible with the enzymatic expression. A study in terms of temperature has shown that inside the mesophilic group of the Desulfovibrio, the behaviour towards this parameter is specific to each bacteria, that accounts for the permanent presence of the representatives of this population in sites where the temperature variations are important. A change of some degrees Celsius can induce modifications in the yields of bacteria growth and by a consequence in variations in the corrosion intensity. Moreover, sulfate D. multispirans can reduce with specific velocities of different growth, the nitrate, the nitrite and the fumarate. Some sulfato-reducing could then adapt themselves to the variations of concentrations in electron acceptors and metabolize the oxidized substances used as biocides too. The choice of an electron acceptor rather than another do not depend uniquely of the specificity of

  5. Complete genome sequence of the acetate-degrading sulfate reducer Desulfobacca acetoxidans type strain (ASRB2T)

    Energy Technology Data Exchange (ETDEWEB)

    Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

    2011-01-01

    Desulfobacca acetoxidans Elferink et al. 1999 is the type species of the genus Desulfobacca, which belongs to the family Syntrophaceae in the class Deltaproteobacteria. The species was first observed in a study on the competition of sulfate-reducers and acetoclastic methanogens for acetate in sludge. D. acetoxidans is considered to be the most abundant acetate-degrading sulfate reducer in sludge. It is of interest due to its isolated phylogenetic location in the 16S rRNA-based tree of life. This is the second completed genome sequence of a member of the family Syntrophaceae to be published and only the third genome sequence from a member of the order Syntrophobacterales. The 3,282,536 bp long genome with its 2,969 protein-coding and 54 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  6. Properties of Desulfovibrio carbinolicus sp. nov. and Other Sulfate-Reducing Bacteria Isolated from an Anaerobic-Purification Plant

    OpenAIRE

    Nanninga, Henk J.; Gottschal, Jan C.

    1987-01-01

    Several sulfate-reducing microorganisms were isolated from an anaerobic-purification plant. Four strains were classified as Desulfovibrio desulfuricans, Desulfovibrio sapovorans, Desulfobulbus propionicus, and Desulfovibrio sp. The D. sapovorans strain contained poly-β-hydroxybutyrate granules and seemed to form extracellular vesicles. A fifth isolate, Desulfovibrio sp. strain EDK82, was a gram-negative, non-spore-forming, nonmotile, curved organism. It was able to oxidize several substrates,...

  7. Anaerobic degradation of sorbic acid by sulfate-reducing and fermenting bacteria : pentanone-2 and isopentanone-2 as byproducts

    OpenAIRE

    Schnell, Sylvia; Wondrak, Christine; Wahl, Günther; Schink, Bernhard

    1991-01-01

    Strictly anaerobic bacteria were enriched and isolated from freshwater sediment sources in the presence and absence of sulfate with sorbic acid as sole source of carbon and energy. Strain WoSol, a Gram-negative vibrioid sulfate-reducing bacterium which was assigned to the species Desulfoarculus (formerly Desulfo-vibrio) baarsii oxidized sorbic acid completely to CO2 with concomitant stoichiometric reduction of sulfate to sulfide. This strain also oxidized a wide variety of fatty acids and oth...

  8. Effect of sulfide, selenite and mercuric mercury on the growth and methylation capacity of the sulfate reducing bacterium Desulfovibrio desulfuricans

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Hoang-Yen T. [Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Chen, Yu-Wei [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada)

    2013-04-01

    Cultures of the sulfate reducing bacteria Desulfovibrio desulfuricans were grown under anoxic conditions to study the effect of added sulfide, selenite and mercuric ions. A chemical trap consisting in a CuSO{sub 4} solution was used to control the poisoning effect induced by the bacterial production of hydrogen sulfide via the precipitation of CuS. Following the addition of Hg{sup 2+}, the formation of methylmercury (MeHg) was correlated to bacterial proliferation with most of MeHg found in the culture medium. A large fraction (50–80%) of added Hg{sup 2+} to a culture ended up in a solid phase (Hg{sup 0} and likely HgS) limiting its bioavailability to cells with elemental Hg representing ∼ 40% of the solid. Following the addition of selenite, a small fraction was converted into Se(0) inside the cells and, even though the conversion to this selenium species increased with the increase of added selenite, it never reached more than 49% of the added amount. The formation of volatile dimethylselenide is suggested as another detoxification mechanism. In cultures containing both added selenite and mercuric ions, elemental forms of the two compounds were still produced and the increase of selenium in the residual fraction of the culture suggests the formation of mercuric selenite limiting the bioavailability of both elements to cells. - Highlights: ► Detoxification mechanisms of D. desulfuricans were studied in presence of added sulfide, selenite and mercuric ions. ► The poisoning effect of H{sub 2}S added to or generated by cultures of D. desulfuricans can be controlled with a chemical trap. ► The addition of selenite to cultures triggered the formation of elemental Se and other forms of volatile and non-volatile Se. ► The addition of mercuric ions to cultures led to the production of methylmercury, volatile Hg and solid mercuric sulfide. ► With both Se and Hg added to cultures, fractionation of species in solid and liquid phases suggests the formation of HgSe.

  9. Suboptimal light conditions influence source-sink metabolism during flowering

    Directory of Open Access Journals (Sweden)

    Annelies eChristiaens

    2016-03-01

    Full Text Available Reliance on carbohydrates during flower forcing was investigated in one early and one late flowering cultivar of azalea (Rhododendron simsii hybrids. Carbohydrate accumulation, invertase activity, and expression of a purported sucrose synthase gene (RsSUS was monitored during flower forcing under suboptimal (natural and optimal (supplemental light light conditions, after a cold treatment (7°C + dark to break flower bud dormancy. Post-production sucrose metabolism and flowering quality was also assessed. Glucose and fructose concentrations and invertase activity increased in petals during flowering, while sucrose decreased. In suboptimal light conditions RsSUS expression in leaves increased as compared to optimal light conditions, indicating that plants in suboptimal light conditions have a strong demand for carbohydrates. However, carbohydrates in leaves were markedly lower in suboptimal light conditions compared to optimal light conditions. This resulted in poor flowering of plants in suboptimal light conditions. Post-production flowering relied on the stored leaf carbon, which could be accumulated under optimal light conditions in the greenhouse. These results show that flower opening in azalea relies on carbohydrates imported from leaves and is source-limiting under suboptimal light conditions.

  10. Detection and Quantification of Functional Genes of Cellulose- Degrading, Fermentative, and Sulfate-Reducing Bacteria and Methanogenic Archaea▿

    Science.gov (United States)

    Pereyra, L. P.; Hiibel, S. R.; Prieto Riquelme, M. V.; Reardon, K. F.; Pruden, A.

    2010-01-01

    Cellulose degradation, fermentation, sulfate reduction, and methanogenesis are microbial processes that coexist in a variety of natural and engineered anaerobic environments. Compared to the study of 16S rRNA genes, the study of the genes encoding the enzymes responsible for these phylogenetically diverse functions is advantageous because it provides direct functional information. However, no methods are available for the broad quantification of these genes from uncultured microbes characteristic of complex environments. In this study, consensus degenerate hybrid oligonucleotide primers were designed and validated to amplify both sequenced and unsequenced glycoside hydrolase genes of cellulose-degrading bacteria, hydA genes of fermentative bacteria, dsrA genes of sulfate-reducing bacteria, and mcrA genes of methanogenic archaea. Specificity was verified in silico and by cloning and sequencing of PCR products obtained from an environmental sample characterized by the target functions. The primer pairs were further adapted to quantitative PCR (Q-PCR), and the method was demonstrated on samples obtained from two sulfate-reducing bioreactors treating mine drainage, one lignocellulose based and the other ethanol fed. As expected, the Q-PCR analysis revealed that the lignocellulose-based bioreactor contained higher numbers of cellulose degraders, fermenters, and methanogens, while the ethanol-fed bioreactor was enriched in sulfate reducers. The suite of primers developed represents a significant advance over prior work, which, for the most part, has targeted only pure cultures or has suffered from low specificity. Furthermore, ensuring the suitability of the primers for Q-PCR provided broad quantitative access to genes that drive critical anaerobic catalytic processes. PMID:20139321

  11. Detection and quantification of functional genes of cellulose- degrading, fermentative, and sulfate-reducing bacteria and methanogenic archaea.

    Science.gov (United States)

    Pereyra, L P; Hiibel, S R; Prieto Riquelme, M V; Reardon, K F; Pruden, A

    2010-04-01

    Cellulose degradation, fermentation, sulfate reduction, and methanogenesis are microbial processes that coexist in a variety of natural and engineered anaerobic environments. Compared to the study of 16S rRNA genes, the study of the genes encoding the enzymes responsible for these phylogenetically diverse functions is advantageous because it provides direct functional information. However, no methods are available for the broad quantification of these genes from uncultured microbes characteristic of complex environments. In this study, consensus degenerate hybrid oligonucleotide primers were designed and validated to amplify both sequenced and unsequenced glycoside hydrolase genes of cellulose-degrading bacteria, hydA genes of fermentative bacteria, dsrA genes of sulfate-reducing bacteria, and mcrA genes of methanogenic archaea. Specificity was verified in silico and by cloning and sequencing of PCR products obtained from an environmental sample characterized by the target functions. The primer pairs were further adapted to quantitative PCR (Q-PCR), and the method was demonstrated on samples obtained from two sulfate-reducing bioreactors treating mine drainage, one lignocellulose based and the other ethanol fed. As expected, the Q-PCR analysis revealed that the lignocellulose-based bioreactor contained higher numbers of cellulose degraders, fermenters, and methanogens, while the ethanol-fed bioreactor was enriched in sulfate reducers. The suite of primers developed represents a significant advance over prior work, which, for the most part, has targeted only pure cultures or has suffered from low specificity. Furthermore, ensuring the suitability of the primers for Q-PCR provided broad quantitative access to genes that drive critical anaerobic catalytic processes.

  12. Acetogenic and sulfate-reducing bacteria inhabiting the rhizoplane and deep cortex cells of the sea grass Halodule wrightii.

    Science.gov (United States)

    Küsel, K; Pinkart, H C; Drake, H L; Devereux, R

    1999-11-01

    Recent declines in sea grass distribution underscore the importance of understanding microbial community structure-function relationships in sea grass rhizospheres that might affect the viability of these plants. Phospholipid fatty acid analyses showed that sulfate-reducing bacteria and clostridia were enriched in sediments colonized by the sea grasses Halodule wrightii and Thalassia testudinum compared to an adjacent unvegetated sediment. Most-probable-number analyses found that in contrast to butyrate-producing clostridia, acetogens and acetate-utilizing sulfate reducers were enriched by an order of magnitude in rhizosphere sediments. Although sea grass roots are oxygenated in the daytime, colorimetric root incubation studies demonstrated that acetogenic O-demethylation and sulfidogenic iron precipitation activities were tightly associated with washed, sediment-free H. wrightii roots. This suggests that the associated anaerobes are able to tolerate exposure to oxygen. To localize and quantify the anaerobic microbial colonization, root thin sections were hybridized with newly developed (33)P-labeled probes that targeted (i) low-G+C-content gram-positive bacteria, (ii) cluster I species of clostridia, (iii) species of Acetobacterium, and (iv) species of Desulfovibrio. Microautoradiography revealed intercellular colonization of the roots by Acetobacterium and Desulfovibrio species. Acetogenic bacteria occurred mostly in the rhizoplane and outermost cortex cell layers, and high numbers of sulfate reducers were detected on all epidermal cells and inward, colonizing some 60% of the deepest cortex cells. Approximately 30% of epidermal cells were colonized by bacteria that hybridized with an archaeal probe, strongly suggesting the presence of methanogens. Obligate anaerobes within the roots might contribute to the vitality of sea grasses and other aquatic plants and to the biogeochemistry of the surrounding sediment.

  13. Community structure and activity of sulfate-reducing bacteria in an intertidal surface sediment: a multi-method approach

    DEFF Research Database (Denmark)

    Llobet-Brossa, Enrique; Rabus, Ralf; Böttcher, Michael E.

    2002-01-01

    The community structure of sulfate-reducing bacteria (SRB) in an intertidal mud flat of the German Wadden Sea (Site Dangast, Jade Bay) was studied and related to sedimentary biogeochemical gradients and processes. Below the penetration depths of oxygen (~3 mm) and nitrate (~4 mm), the presence...... and counting viable cells with the most probable number technique. Phylogenetic groups of SRB identified with these techniques were almost evenly distributed throughout the top 20 cm of the sediment. Application of fluorescence in situ hybridization, however, demonstrated a maximum of active members...

  14. Genome sequence of the thermophilic sulfate-reducing ocean bacterium Thermodesulfatator indicus type strain (CIR29812T)

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain [U.S. Department of Energy, Joint Genome Institute; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Chang, Yun-Juan [ORNL; Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

    2012-01-01

    Thermodesulfatator indicus Moussard et al. 2004 is a member of the genomically so far poorly characterized family Thermodesulfobacteriaceae in the phylum Thermodesulfobacteria. Members of this phylum are of interest because they represent a distinct, deep-branching, Gram-negative lineage. T. indicus is an anaerobic, thermophilic, chemolithoautotrophic sulfate reducer isolated from a deep-sea hydrothermal vent. Here we describe the features of this organism, together with the complete genome sequence, and annotation. The 2,322,224 bp long chromosome with its 2,233 protein-coding and 58 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  15. Complete genome sequence of the thermophilic sulfate-reducing ocean bacterium Thermodesulfatator indicus type strain (CIR29812(T)).

    Science.gov (United States)

    Anderson, Iain; Saunders, Elizabeth; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Tice, Hope; Del Rio, Tijana Glavina; Cheng, Jan-Fang; Han, Cliff; Tapia, Roxanne; Goodwin, Lynne A; Pitluck, Sam; Liolios, Konstantinos; Mavromatis, Konstantinos; Pagani, Ioanna; Ivanova, Natalia; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Jeffries, Cynthia D; Chang, Yun-Juan; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Göker, Markus; Detter, John C; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter

    2012-05-25

    Thermodesulfatator indicus Moussard et al. 2004 is a member of the Thermodesulfobacteriaceae, a family in the phylum Thermodesulfobacteria that is currently poorly characterized at the genome level. Members of this phylum are of interest because they represent a distinct, deep-branching, Gram-negative lineage. T. indicus is an anaerobic, thermophilic, chemolithoautotrophic sulfate reducer isolated from a deep-sea hydrothermal vent. Here we describe the features of this organism, together with the complete genome sequence, and annotation. The 2,322,224 bp long chromosome with its 2,233 protein-coding and 58 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  16. Extracellular Electron Transfer Is a Bottleneck in the Microbiologically Influenced Corrosion of C1018 Carbon Steel by the Biofilm of Sulfate-Reducing Bacterium Desulfovibrio vulgaris.

    Science.gov (United States)

    Li, Huabing; Xu, Dake; Li, Yingchao; Feng, Hao; Liu, Zhiyong; Li, Xiaogang; Gu, Tingyue; Yang, Ke

    2015-01-01

    Carbon steels are widely used in the oil and gas industry from downhole tubing to transport trunk lines. Microbes form biofilms, some of which cause the so-called microbiologically influenced corrosion (MIC) of carbon steels. MIC by sulfate reducing bacteria (SRB) is often a leading cause in MIC failures. Electrogenic SRB sessile cells harvest extracellular electrons from elemental iron oxidation for energy production in their metabolism. A previous study suggested that electron mediators riboflavin and flavin adenine dinucleotide (FAD) both accelerated the MIC of 304 stainless steel by the Desulfovibrio vulgaris biofilm that is a corrosive SRB biofilm. Compared with stainless steels, carbon steels are usually far more prone to SRB attacks because SRB biofilms form much denser biofilms on carbon steel surfaces with a sessile cell density that is two orders of magnitude higher. In this work, C1018 carbon steel coupons were used in tests of MIC by D. vulgaris with and without an electron mediator. Experimental weight loss and pit depth data conclusively confirmed that both riboflavin and FAD were able to accelerate D. vulgaris attack against the carbon steel considerably. It has important implications in MIC failure analysis and MIC mitigation in the oil and gas industry.

  17. Extracellular Electron Transfer Is a Bottleneck in the Microbiologically Influenced Corrosion of C1018 Carbon Steel by the Biofilm of Sulfate-Reducing Bacterium Desulfovibrio vulgaris.

    Directory of Open Access Journals (Sweden)

    Huabing Li

    Full Text Available Carbon steels are widely used in the oil and gas industry from downhole tubing to transport trunk lines. Microbes form biofilms, some of which cause the so-called microbiologically influenced corrosion (MIC of carbon steels. MIC by sulfate reducing bacteria (SRB is often a leading cause in MIC failures. Electrogenic SRB sessile cells harvest extracellular electrons from elemental iron oxidation for energy production in their metabolism. A previous study suggested that electron mediators riboflavin and flavin adenine dinucleotide (FAD both accelerated the MIC of 304 stainless steel by the Desulfovibrio vulgaris biofilm that is a corrosive SRB biofilm. Compared with stainless steels, carbon steels are usually far more prone to SRB attacks because SRB biofilms form much denser biofilms on carbon steel surfaces with a sessile cell density that is two orders of magnitude higher. In this work, C1018 carbon steel coupons were used in tests of MIC by D. vulgaris with and without an electron mediator. Experimental weight loss and pit depth data conclusively confirmed that both riboflavin and FAD were able to accelerate D. vulgaris attack against the carbon steel considerably. It has important implications in MIC failure analysis and MIC mitigation in the oil and gas industry.

  18. Synergy in Sulfur Cycle: The Biogeochemical Significance of Sulfate Reducing Bacteria in Syntrophic Associations

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    organic compounds but they can scavenge hydrogen with high affinity and use it as electron donor or carry out incomplete oxidations of ethanol or lactate with acetate as end product. Most of the species of the ubiquitous well- known genus of Desulfovibrio... of the products of fermentative metabolism are themselves energy source for other fermentative organisms. For example, succinate, lactate and ethanol produced from the fermentation of sugars can be further fermented by other microbes. The bacterium...

  19. Example study for granular bioreactor stratification: Three-dimensional evaluation of a sulfate-reducing granular bioreactor

    Science.gov (United States)

    Hao, Tian-Wei; Luo, Jing-Hai; Su, Kui-Zu; Wei, Li; Mackey, Hamish R.; Chi, Kun; Chen, Guang-Hao

    2016-08-01

    Recently, sulfate-reducing granular sludge has been developed for application in sulfate-laden water and wastewater treatment. However, little is known about biomass stratification and its effects on the bioprocesses inside the granular bioreactor. A comprehensive investigation followed by a verification trial was therefore conducted in the present work. The investigation focused on the performance of each sludge layer, the internal hydrodynamics and microbial community structures along the height of the reactor. The reactor substratum (the section below baffle 1) was identified as the main acidification zone based on microbial analysis and reactor performance. Two baffle installations increased mixing intensity but at the same time introduced dead zones. Computational fluid dynamics simulation was employed to visualize the internal hydrodynamics. The 16S rRNA gene of the organisms further revealed that more diverse communities of sulfate-reducing bacteria (SRB) and acidogens were detected in the reactor substratum than in the superstratum (the section above baffle 1). The findings of this study shed light on biomass stratification in an SRB granular bioreactor to aid in the design and optimization of such reactors.

  20. Subcellular localization of proteins in the anaerobic sulfate reducer Desulfovibrio vulgaris via SNAP-tag labeling and photoconversion

    Energy Technology Data Exchange (ETDEWEB)

    Gorur, A.; Leung, C. M.; Jorgens, D.; Tauscher, A.; Remis, J. P.; Ball, D. A.; Chhabra, S.; Fok, V.; Geller, J. T.; Singer, M.; Hazen, T. C.; Juba, T.; Elias, D.; Wall, J.; Biggin, M.; Downing, K. H.; Auer, M.

    2010-06-01

    Systems Biology studies the temporal and spatial 3D distribution of macromolecular complexes with the aim that such knowledge will allow more accurate modeling of biological function and will allow mathematical prediction of cellular behavior. However, in order to accomplish accurate modeling precise knowledge of spatial 3D organization and distribution inside cells is necessary. And while a number of macromolecular complexes may be identified by its 3D structure and molecular characteristics alone, the overwhelming number of proteins will need to be localized using a reporter tag. GFP and its derivatives (XFPs) have been traditionally employed for subcelllar localization using photoconversion approaches, but this approach cannot be taken for obligate anaerobic bacteria, where the intolerance towards oxygen prevents XFP approaches. As part of the GTL-funded PCAP project (now ENIGMA) genetic tools have been developed for the anaerobe sulfate reducer Desulfovibrio vulgaris that allow the high-throughput generation of tagged-protein mutant strains, with a focus on the commercially available SNAP-tag cell system (New England Biolabs, Ipswich, MA), which is based on a modified O6-alkylguanine-DNA alkyltransferase (AGT) tag, that has a dead-end reaction with a modified O6-benzylguanine (BG) derivative and has been shown to function under anaerobic conditions. After initial challenges with respect to variability, robustness and specificity of the labeling signal we have optimized the labeling. Over the last year, as a result of the optimized labeling protocol, we now obtain robust labeling of 20 out of 31 SNAP strains. Labeling for 13 strains were confirmed at least five times. We have also successfully performed photoconversion on 5 of these 13 strains, with distinct labeling patterns for different strains. For example, DsrC robustly localizes to the periplasmic portion of the inner membrane, where as a DNA-binding protein localizes to the center of the cell, where the

  1. Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Isabel Kimiko Sakamoto

    2012-10-01

    Full Text Available The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN method were 9.0x10(7 cells/mL at the beginning of the assay and 8.0x10(5 cells/mL after 738 hours of operation.

  2. The effect of decreasing alkalinity on microbial community dynamics in a sulfate-reducing bioreactor as analyzed by PCR-SSCP.

    Science.gov (United States)

    Ren, Nanqi; Zhao, Yangguo; Wang, Aijie; Gao, Chongyang; Shang, Huaixiang; Liu, Yiwei; Wan, Chunli

    2006-08-01

    PCR-single-strand conformation polymorphism (SSCP) and Southern blotting techniques were adopted to investigate microbial community dynamics in a sulfate-reducing bioreactor caused by decreasing influent alkalinity. Experimental results indicated that the sulfate-removal rate approached 87% in 25 d under the conditions of influent alkalinity of 4000 mg/L (as CaCO3) and sulfate-loading rate of 4.8 g/(L*d), which indicated that the bioreactor started up successfully. The analysis of microbial community structure in this stage showed that Lactococcus sp., Anaerofilum sp. and Kluyvera sp. were dominant populations. It was found that when influent alkalinity reduced to 1000 mg/L, sulfate-removal rate decreased rapidly to 35% in 3 d. Then influent alkalinity was increased to 3000 mg/L, the sulfate-removal rate rose to 55%. Under these conditions, the populations of Dysgonomonas sp., Sporobacte sp., Obesumbacterium sp. and Clostridium sp. got to rich, which predominated in the community together with Lactococcus sp., Anaerofilum sp. and Kluyvera sp. However, when the alkalinity was decreased to 1500 mg/L, the sulfate-removal rate rose to and kept stable at 70% and populations of Dysgonomonas sp., Sporobacter sp. and Obesumbacterium sp. died out, while some strains of Desulfovibrio sp. and Clostridium sp. increased in concentration. In order to determine the minimum alkalinity value that the system could tolerate, the influent alkalinity was decreased from 1500 to 400 mg/L secondly. This resulted in the sulfate-removal rate, pH value and effluent alkalinity dropping quickly. The amount of Petrotoga sp., Prevotella sp., Kluyvera sp. and Neisseria sp. reduced obviously. The result data from Southern blotting indicated that the amount of sulfate-reducing bacteria (SRBs) decreased with influent alkalinity dropping. Analysis of the microbial community structure and diversity showed that the SRBs populations were very abundant in the inoculated activated sludge and the

  3. Growth and chemosensory behavior of sulfate-reducing bacteria in oxygen-sulfide gradients

    DEFF Research Database (Denmark)

    Sass, Andrea M.; Wieland, Andrea Eschemann; Kühl, Michael

    2002-01-01

    to actively change the extension and slope of the gradients by oxygen reduction with lactate or even sulfide as electron donor. Generally, the chemotactic behavior was in agreement with a defense strategy that re-establishes anoxic conditions, thus promoting anaerobic growth and, in a natural community...

  4. Metabolic profiling reveals metabolic shifts in Arabidopsis plants grown under different light conditions.

    Science.gov (United States)

    Jänkänpää, Hanna Johansson; Mishra, Yogesh; Schröder, Wolfgang P; Jansson, Stefan

    2012-10-01

    Plants have tremendous capacity to adjust their morphology, physiology and metabolism in response to changes in growing conditions. Thus, analysis solely of plants grown under constant conditions may give partial or misleading indications of their responses to the fluctuating natural conditions in which they evolved. To obtain data on growth condition-dependent differences in metabolite levels, we compared leaf metabolite profiles of Arabidopsis thaliana growing under three constant laboratory light conditions: 30 [low light (LL)], 300 [normal light (NL)] and 600 [high light (HL)]µmol photons m(-2) s(-1). We also shifted plants to the field and followed their metabolite composition for 3 d. Numerous compounds showed light intensity-dependent accumulation, including: many sugars and sugar derivatives (fructose, sucrose, glucose, galactose and raffinose); tricarboxylic acid (TCA) cycle intermediates; and amino acids (ca. 30% of which were more abundant under HL and 60% under LL). However, the patterns differed after shifting NL plants to field conditions. Levels of most identified metabolites (mainly amino acids, sugars and TCA cycle intermediates) rose after 2 h and peaked after 73 h, indicative of a 'biphasic response' and 'circadian' effects. The results provide new insight into metabolomic level mechanisms of plant acclimation, and highlight the role of known protectants under natural conditions. © 2012 Blackwell Publishing Ltd.

  5. Quorum Sensing and the Use of Quorum Quenchers as Natural Biocides to Inhibit Sulfate-Reducing Bacteria

    KAUST Repository

    Scarascia, Giantommaso

    2016-12-15

    Sulfate-reducing bacteria (SRB) are one of the main protagonist groups of biocorrosion in the seawater environment. Given their principal role in biocorrosion, it remains a crucial task to develop strategies to reduce the abundance of SRBs. Conventional approaches include the use of biocides and antibiotics, which can impose health, safety, and environmental concerns. This review examines an alternative approach to this problem. This is achieved by reviewing the role of quorum sensing (QS) in SRB populations and its impact on the biofilm formation process. Genome databases of SRBs are mined to look for putative QS systems and homologous protein sequences representative of autoinducer receptors or synthases. Subsequently, this review puts forward the potential use of quorum quenchers as natural biocides against SRBs and outlines the potential strategies for the implementation of this approach.

  6. Quorum Sensing and the Use of Quorum Quenchers as Natural Biocides to Inhibit Sulfate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Giantommaso Scarascia

    2016-12-01

    Full Text Available Sulfate-reducing bacteria (SRB are one of the main protagonist groups of biocorrosion in the seawater environment. Given their principal role in biocorrosion, it remains a crucial task to develop strategies to reduce the abundance of SRBs. Conventional approaches include the use of biocides and antibiotics, which can impose health, safety, and environmental concerns. This review examines an alternative approach to this problem. This is achieved by reviewing the role of quorum sensing (QS in SRB populations and its impact on the biofilm formation process. Genome databases of SRBs are mined to look for putative QS systems and homologous protein sequences representative of autoinducer receptors or synthases. Subsequently, this review puts forward the potential use of quorum quenchers as natural biocides against SRBs and outlines the potential strategies for the implementation of this approach.

  7. Body condition score (BCS and metabolic status of shelter dogs

    Directory of Open Access Journals (Sweden)

    I. Andrighetto

    2010-04-01

    Full Text Available A group of 147 shelter dogs were weighted and assigned a body condition score (BCS using a 9 point scale system, in order to evaluate the prevalence of obesity in the kennel. More than 60% of the animals showed a BCS³6 (overweight and obese and this condition was mainly attributed to an excess of carbohydrates and fat in the diet. In 67/147 dogs, a blood sample was drawn and the effects of BCS, age and time spent in the shelter were evaluated on biochemical parameters. Obese dogs showed significantly higher levels of triglycerides (P<0.01, while increasing BCS determined only an increasing non significant trend on cholesterol values. Age influenced creatinine (P<0.05 and the oldest dogs scoring BCS³6 registered significant higher NEFA (P<0.05 and CK (P=0.01 levels. Time spent in the shelter did not affect any parameter. The dogs’ metabolic condition reflects the need of taking more care of the quality of feed administered in the shelters to avoid the negative health effects caused by chronic obesity.

  8. Desulfovibrio legallis sp. nov.: a moderately halophilic, sulfate-reducing bacterium isolated from a wastewater digestor in Tunisia.

    Science.gov (United States)

    Thabet, Olfa Ben Dhia; Wafa, Terres; Eltaief, Khelifi; Cayol, Jean-Luc; Hamdi, Moktar; Fauque, Guy; Fardeau, Marie-Laure

    2011-02-01

    A new moderately halophilic sulfate-reducing bacterium (strain H₁(T) ) was enriched and isolated from a wastewater digestor in Tunisia. Cells were curved, motile rods (2-3 x 0.5 μm). Strain H₁(T) grew at temperatures between 22 and 43°C (optimum 35°C), and at pH between 5.0 and 9.2 (optimum 7.3-7.5). Strain H₁(T) required salt for growth (1-45 g of NaCl/l), with an optimum at 20-30 g/l. Sulfate, sulfite, thiosulfate, and elemental sulfur were used as terminal electron acceptors but not nitrate and nitrite. Strain H₁(T) utilized lactate, pyruvate, succinate, fumarate, ethanol, and hydrogen (in the presence of acetate and CO₂) as electron donors in the presence of sulfate as electron acceptor. The main end-products from lactate oxidation were acetate with H₂ and CO₂. The G + C content of the genomic DNA was 55%. The predominant fatty acids of strain H₁(T) were C(15:0) iso (38.8%), C(16:0) (19%), and C(14:0) iso 3OH (12.2%), and menaquinone MK-6 was the major respiratory quinone. Phylogenetic analysis of the small-subunit (SSU) ribosomal RNA (rRNA) gene sequence indicated that strain H₁(T) was affiliated to the genus Desulfovibrio. On the basis of SSU rRNA gene sequence comparisons and physiological characteristics, strain H₁(T) is proposed to be assigned to a novel species of sulfate reducers of the genus Desulfovibrio, Desulfovibrio legallis sp. nov. (= DSM 19129(T) = CCUG 54389(T)).

  9. Reduction of chromate (CrO4(2-)) by an enrichment consortium and an isolate of marine sulfate-reducing bacteria.

    Science.gov (United States)

    Cheung, K H; Gu, Ji-Dong

    2003-09-01

    An enrichment consortium and an isolate (isolate TKW) of sulfate-reducing bacteria (SRB) have been obtained from metal-contaminated marine sediments of Tokwawan, Hong Kong SAR. These bacteria are capable of reducing highly toxic and soluble hexavalent chromium (Cr6+) enzymatically into less toxic and insoluble trivalent chromium (Cr3+) under anaerobic conditions. The enrichment consortium almost completely (98.5%) reduced 0.6 mM Cr6+ in 168 h and the rate of reduction was 0.5 g (Cr6+) g(protein)(-1)h(-1). In comparison, with Cr6+ as the sole electron acceptor (as a surrogate for SO4(2-)), isolate TKW reduced 94.5% of the initially added Cr6+ (0.36 mM) in 288 h, with the rate of 0.26 g (Cr6+) g(protein)(-1)h(-1). Adsorption by these bacteria was not the major mechanism contributing to the transformation or removal of Cr6+. The biomass and Cr3+ in the cultures increased simultaneously with the reduction of Cr6+. These indigenous SRB might have potential application in bioremediation of metal contaminated sediments.

  10. Biocorrosion of carbon steel alloys by an hydrogenotrophic sulfate-reducing bacterium Desulfovibrio capillatus isolated from a Mexican oil field separator

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, E. [IRD, Institut de Recherche pour le Developement, Universites de Provence et de la Mediterranee, ESIL Case 925, 163 Avenue de Luminy, F-13288 Marseille, Cedex 09 (France); Bethencourt, M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain)]. E-mail: manuel.bethencourt@uca.es; Botana, F.J. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain); Cano, M.J. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain); Sanchez-Amaya, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain); Corzo, A. [Departamento de Biologia, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain); Garcia de Lomas, J. [Departamento de Biologia, CASEM, Universidad de Cadiz, Poligono Rio San Pedro s/n, 11510 Puerto Real (Spain); Fardeau, M.L. [IRD, Institut de Recherche pour le Developement, Universites de Provence et de la Mediterranee, ESIL Case 925, 163 Avenue de Luminy, F-13288 Marseille, Cedex 09 (France); Ollivier, B. [IRD, Institut de Recherche pour le Developement, Universites de Provence et de la Mediterranee, ESIL Case 925, 163 Avenue de Luminy, F-13288 Marseille, Cedex 09 (France)

    2006-09-15

    The hydrogenotrophic sulfate-reducing bacterium (SRB) Desulfovibrio capillatus (DSM14982{sup T}) was isolated from an oil field separator with serious corrosion problems; this is the study of its role in the corrosion of carbon steels under anaerobic conditions. Immersion tests with two steel alloys, St-35.8 (typical carbon steel employed in European naval industry), and API-5XL52 (weathering alloy steel employed in Mexican oil industries) were performed. Total exposure was 45 days and different concentrations of thiosulfate as electron acceptor for bacterial growth were employed. The samples immersed in media with SRB undergo fast activation and numerous active sites form on the surface. Microscopic observations were made by environmental scanning electron microscopy (ESEM). Weight loss and electrochemical testing included open circuit potential (E {sub corr}), polarization resistance (R {sub p}), electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) were measured with and without bacteria in the culture medium in order to determine corrosion rates and mechanisms. All electrochemical techniques have shown that after the end of the exponential phase the corrosion activity notably increased due to the high concentration of bacterial metabolites. Finally, the corrosion behavior of API-5XL52 was worse than St-35.8.

  11. Carbon and hydrogen stable isotope fractionation associated with the anaerobic degradation of propane and butane by marine sulfate-reducing bacteria.

    Science.gov (United States)

    Jaekel, Ulrike; Vogt, Carsten; Fischer, Anko; Richnow, Hans-Hermann; Musat, Florin

    2014-01-01

    The anaerobic degradation of propane and butane is typically initiated by activation via addition to fumarate. Here we investigated the mechanism of activation under sulfate-reducing conditions by one pure culture (strain BuS5) and three enrichment cultures employing stable isotope analysis. Stable isotope fractionation was compared for cultures incubated with or without substrate diffusion limitation. Bulk enrichment factors were significantly higher in mixed vs. static incubations. Two dimensional factors, given by the correlation of stable isotope fractionation of both carbon and hydrogen at their reactive positions (Lambda reactive position, Λrp), were compared to analyse the activation mechanisms. A characteristic reactive position isotope fractionation pattern was observed, distinct from aerobic degradation. Λrp values ranged from 10.5 to 11.8 for propane and from 7.8 to 9.4 for butane. Incubations of strain BuS5 with deuterium-labelled n-alkanes indicated that butane was activated solely at the subterminal C atom. In contrast, propane was activated mainly at the subterminal C atom but also significantly at the terminal C atoms. A conservative estimate suggests that about 70% of the propane activation events occurred at the subterminal C atom and about 30% at the terminal C atoms. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Temperature and pressure adaptation of a sulfate reducer from the deep subsurface

    Directory of Open Access Journals (Sweden)

    Katja eFichtel

    2015-10-01

    Full Text Available Microbial life in deep marine subsurface faces increasing temperatures and hydrostatic pressure with depth. In this study, we have examined growth characteristics and temperature-related adaptation of the Desulfovibrio indonesiensis strain P23 to the in situ pressure of 30 MPa. The strain originates from the deep subsurface of the eastern flank of the Juan de Fuca Ridge (IODP Site U1301. The organism was isolated at 20 °C and atmospheric pressure from ~61 °C-warm sediments approximately five meters above the sediment-basement interface. In comparison to standard laboratory conditions (20 °C and 0.1 MPa, faster growth was recorded when incubated at in situ pressure and high temperature (45 °C, while cell filamentation was induced by further compression. The maximum growth temperature shifted from 48°C at atmospheric pressure to 50°C under high-pressure conditions. Complementary cellular lipid analyses revealed a two-step response of membrane viscosity to increasing temperature with an exchange of unsaturated by saturated fatty acids and subsequent change from branched to unbranched alkyl moieties. While temperature had a stronger effect on the degree of fatty acid saturation and restructuring of main phospholipids, pressure mainly affected branching and length of side chains. The simultaneous decrease of temperature and pressure to ambient laboratory conditions allowed the cultivation of our moderately thermophilic strain. This may in turn be one key to a successful isolation of microorganisms from the deep subsurface adapted to high temperature and pressure.

  13. Investigation of isotopic and biomolecular approaches as new bio-indicators for long term natural attenuation of monoaromatic compounds in deep terrestrial aquifers by gram-positive sporulated sulfate-reducing bacteria of the genus Desulfotomaculum.

    Directory of Open Access Journals (Sweden)

    Thomas eAüllo

    2016-02-01

    Full Text Available Deep subsurface aquifers despite difficult access, represent important water resources and, at the same time, are key locations for subsurface engineering activities for the oil and gas industries, geothermal energy and CO2 or energy storage. Formation water originating from a 760 meter-deep geological gas storage aquifer was sampled and microcosms were set up to test the biodegradation potential of BTEX by indigenous microorganisms. After a long incubation period, with several subcultures, a sulfate-reducing consortium composed of only two Desulfotomaculum populations was observed able to degrade benzene, toluene and ethylbenzene, extending the number of hydrocarbonoclastic–related species among the Desulfotomaculum genus. Furthermore, we were able to couple specific carbon and hydrogen isotopic fractionation during benzene removal and the results obtained by dual compound specific isotope analysis (εC = -2.4 ‰ ± 0.3 ‰; εH = -57 ‰ ± 0.98 ‰; AKIEC: 1.0146 ± 0.0009 and AKIEH: 1.5184 ± 0.0283 were close to those obtained previously in sulfate-reducing conditions: this finding could confirm the existence of a common enzymatic reaction involving sulfate-reducers to activate benzene anaerobically. Although we cannot assign the role of each population of Desulfotomaculum in the mono-aromatic hydrocarbon degradation, this study suggests an important role of the genus Desulfotomaculum as potential biodegrader among indigenous populations in subsurface habitats. This community represents the simplest model of benzene-degrading anaerobes originating from the deepest subterranean settings ever described. As Desulfotomaculum species are often encountered in subsurface environments, this study provides some interesting results for assessing the natural response of these specific hydrologic systems in response to BTEX contamination during remediation projects.

  14. Nutritional conditioning : The effect of fasting on drug metabolism

    NARCIS (Netherlands)

    Lammers, L.A.

    2018-01-01

    The studies described in this thesis focus on the effect of fasting, as nutritional modulator, on drug metabolism. Drug metabolism varies considerably between and within patients, which may result in treatment failure or, conversely, in untoward side effects. Many factors contribute to the

  15. Removal of Arsenic Using Acid/Metal-Tolerant Sulfate Reducing Bacteria: A New Approach for Bioremediation of High-Arsenic Acid Mine Waters

    Directory of Open Access Journals (Sweden)

    Jennyfer Serrano

    2017-12-01

    Full Text Available Fluvial sediments, soils, and natural waters in northern Chile are characterized by high arsenic (As content. Mining operations in this area are potential sources of As and other metal contaminants, due to acid mine drainage (AMD generation. Sulfate Reducing Bacteria (SRB has been used for the treatment of AMD, as they allow for the reduction of sulfate, the generation of alkalinity, and the removal of dissolved heavy metals and metalloids by precipitation as insoluble metal sulfides. Thus, SRB could be used to remove As and other heavy metals from AMD, however the tolerance of SRB to high metal concentrations and low pH is limited. The present study aimed to quantify the impact of SRB in As removal under acidic and As-Fe-rich conditions. Our results show that SRB tolerate low pH (up to 3.5 and high concentrations of As (~3.6 mg·L−1. Batch experiments showed As removal of up to 73%, Iron (Fe removal higher than 78% and a neutralization of pH from acidic to circum-neutral conditions (pH 6–8. In addition, XRD analysis showed the dominance of amorphous minerals, while Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM-EDX analysis showed associations between As, Fe, and sulfur, indicating the presence of Fe-S-As compounds or interaction of As species with amorphous and/or nanocrystalline phases by sorption processes. These results indicate that the As removal was mediated by acid/metal-tolerant SRB and open the potential for the application of new strains of acid/metal-tolerant SRB for the remediation of high-As acid mine waters.

  16. Optimization of sulfide production by an indigenous consortium of sulfate-reducing bacteria for the treatment of lead-contaminated wastewater.

    Science.gov (United States)

    Kieu, Thi Quynh Hoa; Nguyen, Thi Yen; Dang, Thi Yen; Nguyen, Thanh Binh; Vuong, Thi Nga; Horn, Harald

    2015-10-01

    Biological treatment with sulfate-reducing bacteria (SRB) is considered to be an excellent option to remove heavy metals from wastewater. In this study, the optimization of sulfide production for an enhanced removal of lead by a consortium of SRB was carried out based on central composite design and analyzed using response surface methodology (RSM). The sulfide production process was investigated as a function of three independent variables: solution pH (6.5-8.5), lactate concentration (32-96 mM), and sulfate concentration (16-32 mM). RSM analysis showed that the optimum conditions for a high sulfide concentration (14.2 mM) occurred at a pH of 7.5 and at lactate and sulfate concentrations of 53.4 mM and 22.6 mM, respectively. The lead removal efficiency of the SRB consortium using optimum conditions was determined in four parallel anaerobic continuous moving bed biofilm reactors (V = 2 L) that were fed with synthetic wastewater containing dissolved lead at concentrations of 0, 100, 150, 200 mg L(-1) and operated with a hydraulic retention time of 5 days. 99-100 % was removed from synthetic wastewater with lead concentrations of 100 and 150 mg L(-1) during 40 days of operation. For the highest lead concentration of 200 mg L(-1), a decrease in efficiency of removal (96 %) was observed at the end of the experiment.

  17. Desulfovibrio brasiliensis sp. nov., a moderate halophilic sulfate-reducing bacterium from Lagoa Vermelha (Brazil) mediating dolomite formation.

    Science.gov (United States)

    Warthmann, Rolf; Vasconcelos, Crisogono; Sass, Henrik; McKenzie, Judith A

    2005-06-01

    A novel halotolerant sulfate-reducing bacterium, Desulfovibrio brasiliensis strain LVform1, was isolated from sediments of a dolomite-forming hypersaline coastal lagoon, Lagoa Vermelha, in the state of Rio de Janeiro, Brazil. The cells are vibrio-shaped and 0.30 to 0.45 microm by 1.0 to 3.5 microm in size. These bacteria mediate the precipitation of dolomite [CaMg(CO3)2] in culture experiments. The strain was identified as a member of the genus Desulfovibrio in the delta-subclass of the Proteobacteria on the basis of its 16S rRNA gene sequence, its physiological and morphological properties. Strain LVform1 is obligate sodium-dependent and grows at NaCl concentrations of up to 15%. The 16S rRNA sequence revealed that this strain is closely related to Desulfovibrio halophilus (96.2% similarity) and to Desulfovibrio oxyclinae (96.8% similarity), which were both isolated from Solar Lake, a hypersaline coastal lake in the Sinai, Egypt. Strain LVform1 is barotolerant, growing under pressures of up to 370 bar (37 MPa). We propose strain LVform1 to be the type strain of a novel species of the genus Desulfovibrio, Desulfovibrio brasiliensis (type strain LVform1 = DSMZ No. 15816 and JCM No. 12178). The GenBank/EMBL accession number for the 16S rDNA sequence of strain LVform1 is AJ544687.

  18. Growth Inhibition of Sulfate-Reducing Bacteria in Produced Water from the Petroleum Industry Using Essential Oils

    Directory of Open Access Journals (Sweden)

    Pamella Macedo de Souza

    2017-04-01

    Full Text Available Strategies for the control of sulfate-reducing bacteria (SRB in the oil industry involve the use of high concentrations of biocides, but these may induce bacterial resistance and/or be harmful to public health and the environment. Essential oils (EO produced by plants inhibit the growth of different microorganisms and are a possible alternative for controlling SRB. We aimed to characterize the bacterial community of produced water obtained from a Brazilian petroleum facility using molecular methods, as well as to evaluate the antimicrobial activity of EO from different plants and their major components against Desulfovibrio alaskensis NCIMB 13491 and against SRB growth directly in the produced water. Denaturing gradient gel electrophoresis revealed the presence of the genera Pelobacter and Marinobacterium, Geotoga petraea, and the SRB Desulfoplanes formicivorans in our produced water samples. Sequencing of dsrA insert-containing clones confirmed the presence of sequences related to D. formicivorans. EO obtained from Citrus aurantifolia, Lippia alba LA44 and Cymbopogon citratus, as well as citral, linalool, eugenol and geraniol, greatly inhibited (minimum inhibitory concentration (MIC = 78 µg/mL the growth of D. alaskensis in a liquid medium. The same MIC was obtained directly in the produced water with EO from L. alba LA44 (containing 82% citral and with pure citral. These findings may help to control detrimental bacteria in the oil industry.

  19. Growth Inhibition of Sulfate-Reducing Bacteria in Produced Water from the Petroleum Industry Using Essential Oils.

    Science.gov (United States)

    Souza, Pamella Macedo de; Goulart, Fátima Regina de Vasconcelos; Marques, Joana Montezano; Bizzo, Humberto Ribeiro; Blank, Arie Fitzgerald; Groposo, Claudia; Sousa, Maíra Paula de; Vólaro, Vanessa; Alviano, Celuta Sales; Moreno, Daniela Sales Alviano; Seldin, Lucy

    2017-04-19

    Strategies for the control of sulfate-reducing bacteria (SRB) in the oil industry involve the use of high concentrations of biocides, but these may induce bacterial resistance and/or be harmful to public health and the environment. Essential oils (EO) produced by plants inhibit the growth of different microorganisms and are a possible alternative for controlling SRB. We aimed to characterize the bacterial community of produced water obtained from a Brazilian petroleum facility using molecular methods, as well as to evaluate the antimicrobial activity of EO from different plants and their major components against Desulfovibrio alaskensis NCIMB 13491 and against SRB growth directly in the produced water. Denaturing gradient gel electrophoresis revealed the presence of the genera Pelobacter and Marinobacterium, Geotoga petraea, and the SRB Desulfoplanes formicivorans in our produced water samples. Sequencing of dsrA insert-containing clones confirmed the presence of sequences related to D. formicivorans. EO obtained from Citrus aurantifolia, Lippia alba LA44 and Cymbopogon citratus, as well as citral, linalool, eugenol and geraniol, greatly inhibited (minimum inhibitory concentration (MIC) = 78 µg/mL) the growth of D. alaskensis in a liquid medium. The same MIC was obtained directly in the produced water with EO from L. alba LA44 (containing 82% citral) and with pure citral. These findings may help to control detrimental bacteria in the oil industry.

  20. Properties of Desulfovibrio carbinolicus sp. nov. and Other Sulfate-Reducing Bacteria Isolated from an Anaerobic-Purification Plant.

    Science.gov (United States)

    Nanninga, H J; Gottschal, J C

    1987-04-01

    Several sulfate-reducing microorganisms were isolated from an anaerobic-purification plant. Four strains were classified as Desulfovibrio desulfuricans, Desulfovibrio sapovorans, Desulfobulbus propionicus, and Desulfovibrio sp. The D. sapovorans strain contained poly-beta-hydroxybutyrate granules and seemed to form extracellular vesicles. A fifth isolate, Desulfovibrio sp. strain EDK82, was a gram-negative, non-spore-forming, nonmotile, curved organism. It was able to oxidize several substrates, including methanol. Sulfate, sulfite, thiosulfate, and sulfur were utilized as electron acceptors. Pyruvate, fumarate, malate, and glycerol could be fermented. Because strain EDK82 could not be ascribed to any of the existing species, a new species, Desulfovibrio carbinolicus, is proposed. The doubling times of the isolates were determined on several substrates. Molecular hydrogen, lactate, propionate, and ethanol yielded the shortest doubling times (3.0 to 6.3 h). Due to the presence of support material in an anaerobic filter system, these species were able to convert sulfate to sulfide very effectively at a hydraulic retention time as short as 0.5 h.

  1. Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps.

    Science.gov (United States)

    Jaekel, Ulrike; Musat, Niculina; Adam, Birgit; Kuypers, Marcel; Grundmann, Olav; Musat, Florin

    2013-05-01

    The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.

  2. Experimental study on treating agate dyeing wastewater with sulfate-reducing bacteria strengthening peanut shells and scrap iron.

    Science.gov (United States)

    Di, Junzhen; Wang, Mingxin

    2017-08-01

    To solve the problems of high concentrations of Cr(6+), SO4(2-) and H(+) in agate dyeing industrial wastewater and heavy pollution and high treating cost, single-factor and orthogonal experiments were conducted to determine the optimum particle size, the ratio of adsorbents dosing and hydraulic retention time based on peanut shells and scrap iron. Experiments, using five dynamic columns filled with the peanut shells, scrap iron and sulfate-reducing bacteria (SRB), were also conducted to determine the effect and mechanism of treating the wastewater. The results show that the best treatment effect was obtained when the diameter of peanut shells was 3 mesh, scrap iron being 60 mesh size, scrap iron and peanut shells with a ratio of 1:2, and hydraulic retention time being 24 h. By the comprehensive comparison of five groups of columns, the treating effect of column 4 was best, in which the removal rate of SO4(2-) and Cr(6+) was 30.17% and 88.36% respectively before adding the microorganisms, and 25.34% and 99.31% respectively after adding the microorganisms. The average of chemical oxygen demand (COD) release quantity was 62.11 and 513.75 mg·L(-1), and the average effluent pH was 7.09 and 7.93 before and after addition of microorganisms respectively. In conclusion, peanut shells, scrap iron and SRB had a certain synergistic effect on treating agate dyeing wastewater.

  3. Thermodesulfobacterium geofontis sp. nov., a hyperthermophilic, sulfate-reducing bacterium isolated from Obsidian Pool, Yellowstone National Park.

    Science.gov (United States)

    Hamilton-Brehm, Scott D; Gibson, Robert A; Green, Stefan J; Hopmans, Ellen C; Schouten, Stefan; van der Meer, Marcel T J; Shields, John P; Damsté, Jaap S S; Elkins, James G

    2013-03-01

    A novel sulfate-reducing bacterium designated OPF15(T) was isolated from Obsidian Pool, Yellowstone National Park, Wyoming. The phylogeny of 16S rRNA and functional genes (dsrAB) placed the organism within the family Thermodesulfobacteriaceae. The organism displayed hyperthermophilic temperature requirements for growth with a range of 70-90 °C and an optimum of 83 °C. Optimal pH was around 6.5-7.0 and the organism required the presence of H2 or formate as an electron donor and CO2 as a carbon source. Electron acceptors supporting growth included sulfate, thiosulfate, and elemental sulfur. Lactate, acetate, pyruvate, benzoate, oleic acid, and ethanol did not serve as electron donors. Membrane lipid analysis revealed diacyl glycerols and acyl/ether glycerols which ranged from C14:0 to C20:0. Alkyl chains present in acyl/ether and diether glycerol lipids ranged from C16:0 to C18:0. Straight, iso- and anteiso-configurations were found for all lipid types. The presence of OPF15(T) was also shown to increase cellulose consumption during co-cultivation with Caldicellulosiruptor obsidiansis, a fermentative, cellulolytic extreme thermophile isolated from the same environment. On the basis of phylogenetic, phenotypic, and structural analyses, Thermodesulfobacterium geofontis sp. nov. is proposed as a new species with OPF15(T) representing the type strain.

  4. Hybrid soliwave technique for mitigating sulfate-reducing bacteria in controlling biocorrosion: a case study on crude oil sample.

    Science.gov (United States)

    Mohd Ali, Muhammad Khairool Fahmy Bin; Abu Bakar, Akrima; Md Noor, Norhazilan; Yahaya, Nordin; Ismail, Mardhiah; Rashid, Ahmad Safuan

    2017-10-01

    Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and deep-water pipelines that result in costly repair and pipeline failure. Sulfate-reducing bacteria (SRB) are commonly known as the culprit of MIC. The aim of this work is to investigate the performance of combination of ultrasound (US) irradiation and ultraviolet (UV) radiation (known as Hybrid soliwave technique, HyST) at pilot scale to inactivate SRB. The influence of different reaction times with respect to US irradiation and UV radiation and synergistic effect toward SRB consortium was tested and discussed. In this research, the effect of HyST treatment toward SRB extermination and corrosion studies of carbon steel coupon upon SRB activity before and after the treatment were performed using weight loss method. The carbon steel coupons immersed in SRB sample were exposed to HyST treatment at different time of exposure. Additionally, Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy were used to investigate the corrosion morphology in verifying the end product of SRB activity and corrosion formation after treatment. Results have shown that the US irradiation treatment gives a synergistic effect when combined with UV radiation in mitigating the SRB consortium.

  5. Production of biosurfactant from Bacillus licheniformis for microbial enhanced oil recovery and inhibition the growth of sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    H.S. El-Sheshtawy

    2015-06-01

    Full Text Available In this study, the bacterium Bacillus licheniformis has been isolated from oil reservoir; the ability of this bacterium to produce a biosurfactant was detected. Surface properties of the produced biosurfactant were confirmed by determining the emulsification power as well as surface and interfacial tension. The crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was about 1 g/l. Also, chemical structure of the produced biosurfactant was confirmed using FTIR analysis. Results revealed that, the emulsification power has been increased up to 96% and the surface tension decreased from 72 of distilled water to 36 mN/m after 72 h of incubation. The potential application of this bacterial species in microbial-enhanced oil recovery (MEOR was investigated. The percent of oil recovery was 16.6% upon application in a sand pack column designed to stimulate an oil recovery. It also showed antimicrobial activity against the growth of different strains of SRB (sulfate reducing bacteria. Results revealed that a complete inhibition of SRB growth using 1.0% crude biosurfactant is achieved after 3 h.

  6. Microbial Corrosion in Linepipe Steel Under the Influence of a Sulfate-Reducing Consortium Isolated from an Oil Field

    Science.gov (United States)

    AlAbbas, Faisal M.; Williamson, Charles; Bhola, Shaily M.; Spear, John R.; Olson, David L.; Mishra, Brajendra; Kakpovbia, Anthony E.

    2013-11-01

    This work investigates microbiologically influenced corrosion of API 5L X52 linepipe steel by a sulfate-reducing bacteria (SRB) consortium. The SRB consortium used in this study was cultivated from a sour oil well in Louisiana, USA. 16S rRNA gene sequence analysis indicated that the mixed bacterial consortium contained three phylotypes: members of Proteobacteria ( Desulfomicrobium sp.), Firmicutes ( Clostridium sp.), and Bacteroidetes ( Anaerophaga sp.). The biofilm and the pits that developed with time were characterized using field emission scanning electron microscopy (FE-SEM). In addition, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and open circuit potential (OCP) were used to analyze the corrosion behavior. Through circuit modeling, EIS results were used to interpret the physicoelectric interactions between the electrode, biofilm and solution interfaces. The results confirmed that extensive localized corrosion activity of SRB is due to a formed biofilm in conjunction with a porous iron sulfide layer on the metal surface. X-ray diffraction (XRD) revealed semiconductive corrosion products predominantly composed of a mixture of siderite (FeCO3), iron sulfide (Fe x S y ), and iron (III) oxide-hydroxide (FeOOH) constituents in the corrosion products for the system exposed to the SRB consortium.

  7. Long-term competition between sulfate reducing and methanogenic bacteria in UASB reactors treating volatile fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Omil, F. [Agricultural Univ. of Wageningen (Netherlands). Dept. of Environmental Technology]|[Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering; Lens, P.; Visser, A.; Hulshoff Pol, L.W.; Lettinga, G. [Agricultural Univ. of Wageningen (Netherlands). Dept. of Environmental Technology

    1998-03-20

    The competition between acetate utilizing methane-producing bacteria (MB) and sulfate-reducing bacteria (SRB) was studied in mesophilic (30 C) upflow anaerobic sludge bed (UASB) reactors treating volatile fatty acids and sulfate. The UASB reactors treated a VFA mixture (with an acetate:propionate:butyrate ratio of 5:3:2 on COD basis) or acetate as the sole substrate at different COD:sulfate ratios. The outcome of the competition was evaluated in terms of conversion rates and specific methanogenic and sulfidogenic activities. The COD:sulfate ratio was a key factor in the partitioning of acetate utilization between MB and SRB. In excess of sulfate, SRB became predominant over MB after prolonged reactor operation: 250 and 400 days were required to increase the amount of acetate used by SRB from 50 to 90% in the reactor treating, respectively, the VFA mixture or acetate as the sole substrate. The competition for acetate was further studied by dynamic simulations using a mathematical model based on the Monod kinetic parameters of acetate utilizing SRB and MB. The simulations confirmed the long term nature of the competition between these acetotrophs. A high reactor pH ({+-}8), a short solid retention time (<150 days), and the presence of a substantial SRB population in the inoculum may considerably reduce the time required for acetate-utilizing SRB to outcompete MB.

  8. Volatile sulfur production by pig cecal bacteria in batch culture and screening inhibitors of sulfate reducing bacteria.

    Science.gov (United States)

    Arakawa, T; Ishikawa, Y; Ushida, K

    2000-08-01

    We studied the effects of specific inhibitors of methanogenesis (2-bromoethane sulfonate, BES) and sulfate reduction (sodium molybdate) on volatile sulfur production in batch cultures of pig cecal bacteria. The volatile sulfur concentration in headspace gas was determined by flame-photometric detector gas chromatography. BES stimulated production of hydrogen sulfide (H2S) and methanethiol, and sodium molybdate completely inhibited the production of these volatile sulfur compounds. The results indicated that dissimilate sulfate reduction is mainly responsible for volatile sulfur production in the hindgut. Therefore the extracts of herbs, food colors, and aroma chemicals were tested for their inhibitory effects on H2S production by a dissimilatory sulfate-reducing bacteria. Desulfovibrio desulfuricans DSM642. H2S was measured by the chromatography of the headspace gas, using a flame photometric detector. Of 306 herbal extracts tested, 69 extracts from 38 herbs inhibited H2S production at 1.0 mg/mL. Sisymbrium officinale (hedge mustard) was the most potent inhibitor. Six pigments inhibited H2S release. Erythrosine and rose bengal showed inhibitory effects at 0.01 mg/mL. Peppermint oil and 96 aroma chemicals were assayed for their effects on H2S release. Thirty-two aroma chemicals suppressed H2S production at 0.1 mg/mL, and camphene, 1-decanol, and 2-nonanone were effective at 0.01 mg/mL.

  9. Properties of Desulfovibrio carbinolicus sp. nov. and other sulfate-reducing bacteria isolated from an anaerobic-purification plant

    Energy Technology Data Exchange (ETDEWEB)

    Nanninga, H.J.; Gottschal, J.C.

    1987-04-01

    Several sulfate-reducing microorganisms were isolated from an anaerobic-purification plant. Four strains were classified as Desulfovibrio desulfuricans, Desulfovibrio sapovorans, Desulfobulbus propionicus, and Desulfovibrio sp. The D. sapovorans strain contained poly-..beta..-hydroxybutyrate granules and seemed to form extracellular vesicles. A fifth isolate, Desulfovibrio sp. strain EDK82, was a gram-negative, non-spore-forming, nonmotile, curved organism. It was able to oxidize several substrates, including methanol. Sulfate, sulfite, thiosulfate, and sulfur were utilized as electron acceptors. Pyruvate, fumarate, malate, and glycerol could be fermented. Because strain EDK82 could not be ascribed to any of the existing species, a new species, Desulfovibrio carbinolicus, is proposed. The doubling times of the isolates were determined on several substrates. Molecular hydrogen, lactate, propionate, and ethanol yielded the shortest doubling times (3.0 to 6.3 h). Due to the presence of support material in an anaerobic filter system, these species were able to convert sulfate to sulfide very effectively at a hydraulic retention time as short as 0.5 h.

  10. Removal of chromium from synthetic plating waste by zero-valent iron and sulfate-reducing bacteria.

    Science.gov (United States)

    Guha, Saumyen; Bhargava, Puja

    2005-01-01

    Experiments were conducted to evaluate the potential of zero-valent iron and sulfate-reducing bacteria (SRB) for reduction and removal of chromium from synthetic electroplating waste. The zero-valent iron shows promising results as a reductant of hexavalent chromium (Cr+6) to trivalent chromium (Cr+3), capable of 100% reduction. The required iron concentration was a function of chromium concentration in the waste stream. Removal of Cr+3 by adsorption or precipitation on iron leads to complete removal of chromium from the waste and was a slower process than the reduction of Cr+6. Presence SRB in a completely mixed batch reactor inhibited the reduction of Cr+6. In a fixed-bed column reactor, SRB enhanced chromium removal and showed promising results for the treatment of wastes with low chromium concentrations. It is proposed that, for waste with high chromium concentration, zero-valent iron is an efficient reductant and can be used for reduction of Cr+6. For low chromium concentrations, a SRB augmented zero-valent iron and sand column is capable of removing chromium completely.

  11. Thermodesulfobacterium geofontis sp. nov., a hyperthermophilic, sulfate-reducing bacterium isolated from Obsidian Pool, Yellowstone National Park

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton-Brehm, Scott D.; Gibson, Robert A.; Green, Stefan J.; Hopmans, Ellen C.; Schouten, Stefan; van der Meer, Marcel T. J.; Shields, John P.; Damsté, Jaap S. S.; Elkins, James G.

    2013-01-24

    A novel sulfate-reducing bacterium designated OPF15T was isolated from Obsidian Pool, Yellowstone National Park, Wyoming. The phylogeny of 16S rRNA and functional genes (dsrAB) placed the organism within the family Thermodesulfobacteriaceae. The organism displayed hyperthermophilic temperature requirements for growth with a range of 70 90 C and an optimum of 83 C. Optimal pH was around 6.5 7.0 and the organism required the presence of H2 or formate as an electron donor and CO2 as a carbon source. Electron acceptors supporting growth included sulfate, thiosulfate, and elemental sulfur. Lactate, acetate, pyruvate, benzoate, oleic acid, and ethanol did not serve as electron donors. Membrane lipid analysis revealed diacyl glycerols and acyl/ether glycerols which ranged from C14:0 to C20:0. Alkyl chains present in acyl/ether and diether glycerol lipids ranged from C16:0 to C18:0. Straight, iso- and anteiso-configurations were found for all lipid types. The presence of OPF15T was also shown to increase cellulose consumption during co-cultivation with Caldicellulosiruptor obsidiansis, a fermentative, cellulolytic extreme thermophile isolated from the same environment. On the basis of phylogenetic, phenotypic, and structural analyses, Thermodesulfobacterium geofontis sp. nov. is proposed as a new species with OPF15T representing the type strain.

  12. Unusual Starch Degradation Pathway via Cyclodextrins in the Hyperthermophilic Sulfate-Reducing Archaeon Archaeoglobus fulgidus Strain 7324▿

    Science.gov (United States)

    Labes, Antje; Schönheit, Peter

    2007-01-01

    The hyperthermophilic archaeon Archaeoglobus fulgidus strain 7324 has been shown to grow on starch and sulfate and thus represents the first sulfate reducer able to degrade polymeric sugars. The enzymes involved in starch degradation to glucose 6-phosphate were studied. In extracts of starch-grown cells the activities of the classical starch degradation enzymes, α-amylase and amylopullulanase, could not be detected. Instead, evidence is presented here that A. fulgidus utilizes an unusual pathway of starch degradation involving cyclodextrins as intermediates. The pathway comprises the combined action of an extracellular cyclodextrin glucanotransferase (CGTase) converting starch to cyclodextrins and the intracellular conversion of cyclodextrins to glucose 6-phosphate via cyclodextrinase (CDase), maltodextrin phosphorylase (Mal-P), and phosphoglucomutase (PGM). These enzymes, which are all induced after growth on starch, were characterized. CGTase catalyzed the conversion of starch to mainly β-cyclodextrin. The gene encoding CGTase was cloned and sequenced and showed highest similarity to a glucanotransferase from Thermococcus litoralis. After transport of the cyclodextrins into the cell by a transport system to be defined, these molecules are linearized via a CDase, catalyzing exclusively the ring opening of the cyclodextrins to the respective maltooligodextrins. These are degraded by a Mal-P to glucose 1-phosphate. Finally, PGM catalyzes the conversion of glucose 1-phosphate to glucose 6-phosphate, which is further degraded to pyruvate via the modified Embden-Meyerhof pathway. PMID:17921308

  13. Metabolic syndrome and peripheral artery disease: Two related conditions.

    Science.gov (United States)

    Oriol Torón, Pilar Ángeles; Badía Farré, Teresa; Romaguera Lliso, Amparo; Roda Diestro, Jovita

    2016-01-01

    To ascertain the prevalence of metabolic syndrome (MS) in patients with peripheral artery disease (PAD) at the Martorell primary care (PC) center. To analyze the differences in comorbidities and cardiovascular risk factors between patients with PAD with and without MS. A cross-sectional, descriptive study on patients diagnosed with PAD according to computerized clinical records of the Martorell PC center. Variables collected included age, sex, high blood pressure (HBP), dyslipidemia (DLP), diabetes (DM), smoking, obesity, cardiovascular disease (CVD), erectile dysfunction (ED), renal failure (RF), and oligoalbuminuria. An analysis comparing patients with and without MS was performed. There were 131 patients diagnosed with PAD, 104 (79%) of whom were male. Sixty-three (48.1%) also had MS. Patients with both PAD and MS had, as compared to those with PAD only, a higher prevalence of HBP (87.3 vs. 60.3%, P: 0.001), DLP (77.8 vs. 60.3%, P: 0.03), DM (69.8 vs. 30.9%, P<.001), obesity (25.4 vs. 10.3%, P: 0.03), CVD (42.9 vs. 19.1%); P: 0.004), ED (81.3 vs. 54.3%, P: 0.02), and RF (40.3 vs. 17.9%, P: 0.006). Patients with both PAD and MS had a higher prevalence of HBP, DLP, DM, and obesity. They also had more cardiovascular events and were significantly associated with pathological conditions highly relevant for cardiovascular prognosis such as erectile dysfunction and chronic kidney disease. Copyright © 2016 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

  14. Degree of sulfate-reducing activities on COD removal in various reactor configurations in anaerobic glucose and acetate-fed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Erdirencelebi, Dilek [Environmental Engineering Department, Selcuk University (Turkey); Ozturk, Izzet; Ubay Cokgor, Emine [Environmental Engineering Department, Istanbul Technical University, Istanbul (Turkey); Ubay Tonuk, Gulseren [City and Regional Planing, Gazi University, Ankara (Turkey)

    2007-04-15

    Sulfate-reduction data from various anaerobic reactor configurations, e. g., upflow anaerobic sludge blanket reactor (UASBR), completely stirred tank reactor (CSTR), and batch reactor (BR) with synthetic wastewaters, having glucose and acetate as the substrates and different levels of sulfate, were evaluated to determine the level of sulfate-reducing activity by sulfate-reducing bacteria coupled to organic matter removal. Anaerobic reactors were observed for the degree of competition between sulfate-reducing sulfidogens and methane producing bacteria during the degradation of glucose and acetate. Low sulfate-reducing activity was obtained with a maximum of 20% of organic matter degradation with glucose-fed upflow anaerobic sludge bed reactors (UASBRs), while a minimum of 2% was observed with acetate-fed batch reactors. The highest sulfate removal performance (72-89%) was obtained from glucose fed-UASB reactors, with the best results observed with increasing COD/SO{sub 4} ratios. UASB reactors produced the highest level of sulfidogenic activity, with the highest sulfate removal and without a performance loss. Hence, this was shown to be the optimum reactor configuration. Dissolved sulfide produced as a result of sulfate reduction reached 325 mg/L and 390 mg/L in CST and UASB reactors, respectively, and these levels were tolerated. The sulfate removal rate was higher at lower COD/SO{sub 4} ratios, but the degree of sulfate removal improved with increasing COD/SO{sub 4} ratios. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  15. Characterization of the sulfate-reducing and syntrophic population in granular sludge from a full-scale anaerobic reactor treating papermill wastewater.

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.; Vorstman, W.J.C.; Sopjes, A.; Stams, A.J.M.

    1998-01-01

    To gain more insight into the competitive and syntrophic interactions between sulfate-reducing and methanogenic consortia in sulfate-limited anaerobic reactors, the microbial population in granular sludge from a full-scale upflow anaerobic sludge blanket (UASB) reactor was studied, using the 16S

  16. Identification of sulfate reducers and Syntrophobacter sp. in anaerobic granular sludge by fatty-acid biomarkers and 16S rRNA probing

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.; Boschker, H.T.S.; Stams, A.J.M.

    1998-01-01

    The sulfate-reducing bacterial sludge population in anaerobic bioreactors, treating different types of wastewater in the presence or absence of sulfate, was evaluated by polar-lipid fatty acid (PLFA) analyses, and by 16S rRNA dot-blot hybridizations using specific 16S rRNA-targeted oligonucleotide

  17. Identification of sulfate reducers and Syntrophobacter sp. in anaerobic granular sludge by fatty-acid biomarkers and 16S rRNA probing

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.; Boschker, H.T.S.; Stams, A.J.M.

    1998-01-01

    The sulfate-reducing bacterial sludge population in anaerobic bioreactors, treating different types of wastewater in the presence or absence of sulfate, was evaluated by polar-lipid fatty acid (PLFA) analyses, and by 16S rRNA dot-blot hybridizations using specific 16S rRNA- targeted oligonucleotide

  18. Assessment of compatible solutes to overcome salinity stress in thermophilic (55 oC) methanol-fed sulfate reducing granular sludges

    NARCIS (Netherlands)

    Vallero, M.V.G.; Lettinga, G.; Lens, P.N.L.

    2003-01-01

    High NaCl concentrations (25 g.L-1) considerably decreased the methanol depletion rates for sludges harvested from two lab-scale sulfate reducing UASB reactors. In addition, 25 gNaCl.L-1 strongly affected the fate of methanol degradation, with clear increase in the acetate production at the expense

  19. Desulfovibrio paquesii sp. nov., a hydrogenotrophic sulfate-reducing bacterium isolated from a synthesis-gas-fed bioreactor treating zinc- and sulfate-rich wastewater

    NARCIS (Netherlands)

    Houten, van B.H.G.W.; Meulepas, R.J.W.; Doesburg, van W.; Smidt, H.; Muyzer, G.; Stams, A.J.M.

    2009-01-01

    A hydrogenotrophic, sulfate-reducing bacterium, designated strain SB1(T), was isolated from sulfidogenic sludge of a full-scale synthesis-gas-fed bioreactor used to remediate wastewater from a zinc smelter. Strain SB1(T) was found to be an abundant micro-organism in the sludge at the time of

  20. Desulfonatronovibrio halophilus sp. nov., a novel moderately halophilic sulfate-reducing bacterium from hypersaline chloride-sulfate lakes in Central Asia

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Abbas, B.; Suhacheva, M.V.; Muyzer, G.

    2012-01-01

    Four strains of lithotrophic sulfate-reducing bacteria (SRB) have been enriched and isolated from anoxic sediments of hypersaline chloride-sulfate lakes in the Kulunda Steppe (Altai, Russia) at 2 M NaCl and pH 7.5. According to the 16S rRNA gene sequence analysis, the isolates were closely related

  1. Coexistence of physiologically similar sulfate reducing bacteria in a full-scale sulfidogenic bioreactor fed with a single organic electron donor

    NARCIS (Netherlands)

    Dar, S.; Stams, A.J.M.; Kuenen, J.G.; Muyzer, G.

    2007-01-01

    A combination of culture-dependent and independent methods was used to study the co-existence of different sulfate-reducing bacteria (SRB) in an upflow anaerobic sludge bed reactor treating sulfate-rich wastewater. The wastewater was fed with ethanol as an external electron donor. Twenty six strains

  2. Effect of nitrate addition on the diversity and activity of sulfate-reducing prokaryotes in high-temperature oil production systems

    DEFF Research Database (Denmark)

    Gittel, Antje; Wieczorek, Adam; Sørensen, Ketil

    Sulfate-reducing prokaryotes (SRP) producing hydrogen sulfide cause severe problems like microbial corrosion, souring and plugging in seawater-injected oil production systems. Adding nitrate to the injection water is a possible strategy to control the activity of SRP by favoring the growth of both...

  3. Effect of specific gas loading rate on thermophilic (55°) acidifying (pH6) and sulfate reducing granular sludge reactors

    NARCIS (Netherlands)

    Lens, P.N.L.; Klijn, R.; Lier, van J.B.; Lettinga, G.

    2003-01-01

    The effect of the specific gas loading rate on the acidifying, sulfate reducing and sulfur removal capacity of thermophilic (55degreesC; pH 6.0) granular sludge bed reactors treating partly acidified wastewater was investigated. A comparison was made between a regular UASB reactor and a UASB reactor

  4. Prokaryotic community structure and activity of sulfate reducers in production water from high-temperature oil reservoirs with and without nitrate treatment

    DEFF Research Database (Denmark)

    Gittel, Antje; Sørensen, Ketil; Skovhus, Torben L.

    2009-01-01

    Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. One strategy to control SRP activity is the addition of nitrate to the injection water. Production waters from two adjacent, hot (80°C) oil reservoirs...

  5. Spatio-temporal dynamics of sulfate-reducing bacteria in extreme environment of Rogoznica Lake revealed by 16S rRNA analysis

    Science.gov (United States)

    Čanković, Milan; Petrić, Ines; Marguš, Marija; Ciglenečki, Irena

    2017-08-01

    Highly eutrophic and euxinic seawater system of Rogoznica Lake (Croatia) was used as a study site for investigation of distribution, diversity and abundance of sulfate-reducing bacteria (SRB) during stratified conditions in the summer and winter season, by targeting 6 phylogenetic subgroups of SRB. 16S rRNA gene sequences indicated that community cannot be directly related to cultured SRB species but rather that Rogoznica Lake harbors habitat-specific SRB populations associated to bacteria belonging to δ-Proteobacteria with few Firmicutes and Verrucomicrobium-related populations. Clear spatial-temporal shifts in the SRB community structure were observed. Results implied existence of distinct SRB populations between the water column and sediment, as well as higher diversity of the SRB occupying water layer then the ones found in the sediment. Likewise, seasonal variations in populations were observed. While SRB community was more diverse in the winter compared to the summer season in the water layer, situation was opposite in the sediment. Water layer communities seem to be more susceptible to changes of physico-chemical parameters, while those in the sediment have prorogated response to these changes. Results indicate that SRB diversity is still highly underestimated in natural environments, especially in specific habitats such as Rogoznica Lake. Presented data show a complex SRB diversity and distribution supporting the idea that habitat-specific SRB communities are important part of the anaerobic food chain in degradation of organic matter as well as cycling of sulfur and carbon species in the Lake and similar anoxic environment.

  6. Anaerobic BTEX degradation in oil sands tailings ponds: Impact of labile organic carbon and sulfate-reducing bacteria.

    Science.gov (United States)

    Stasik, Sebastian; Wick, Lukas Y; Wendt-Potthoff, Katrin

    2015-11-01

    The extraction of bitumen from oil sands in Alberta (Canada) produces volumes of tailings that are pumped into large anaerobic settling-basins. Beside bitumen, tailings comprise fractions of benzene, toluene, ethylbenzene and xylenes (BTEX) that derive from the application of industrial solvents. Due to their toxicity and volatility, BTEX pose a strong concern for gas- and water-phase environments in the vicinity of the ponds. The examination of two pond profiles showed that concentrations of indigenous BTEX decreased with depth, pointing at BTEX transformation in situ. With depth, the relative contribution of ethylbenzene and xylenes to total BTEX significantly decreased, while benzene increased relatively from 44% to 69%, indicating preferential hydrocarbon degradation. To predict BTEX turnover and residence time, we determined BTEX degradation rates in tailings of different depths in a 180-days microcosm study. In addition, we evaluated the impact of labile organic substrates (e.g. acetate) generally considered to stimulate hydrocarbon degradation and the contribution of sulfate-reducing bacteria (SRB) to BTEX turnover. In all depths, BTEX concentrations significantly decreased due to microbial activity, with degradation rates ranging between 4 and 9 μg kg(-1) d(-1). BTEX biodegradation decreased linearly in correlation with initial concentrations, suggesting a concentration-dependent BTEX transformation. SRB were not significantly involved in BTEX consumption, indicating the importance of methanogenic degradation. BTEX removal decreased to 70-90% in presence of organic substrates presumptively due to an accumulation of acetate that lowered BTEX turnover due to product inhibition. In those assays SRB slightly stimulated BTEX transformation by reducing inhibitory acetate levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Selective cathodic microbial biofilm retention allows a high current-to-sulfide efficiency in sulfate-reducing microbial electrolysis cells.

    Science.gov (United States)

    Pozo, Guillermo; Lu, Yang; Pongy, Sebastien; Keller, Jürg; Ledezma, Pablo; Freguia, Stefano

    2017-12-01

    Selective microbial retention is of paramount importance for the long-term performance of cathodic sulfate reduction in microbial electrolysis cells (MECs) due to the slow growth rate of autotrophic sulfate-reducing bacteria. In this work, we investigate the biofilm retention and current-to-sulfide conversion efficiency using carbon granules (CG) or multi-wall carbon nanotubes deposited on reticulated vitreous carbon (MWCNT-RVC) as electrode materials. For ~2months, the MECs were operated at sulfate loading rates of 21 to 309gSO4 -S/m2/d. Although MWCNT-RVC achieved a current density of 57±11A/m2, greater than the 32±9A/m2 observed using CG, both materials exhibited similar sulfate reduction rates (SRR), with MWCNT-RVC reaching 104±16gSO4 -S/m2/d while 110±13gSO4 -S/m2/d were achieved with CG. Pyrosequencing analysis of the 16S rRNA at the end of experimentation revealed a core community dominated by Desulfovibrio (28%), Methanobacterium (19%) and Desulfomicrobium (14%), on the MWCNT-RVC electrodes. While a similar Desulfovibrio relative abundance of 29% was found in CG-biofilms, Desulfomicrobium was found to be significantly less abundant (4%) and Methanobacterium practically absent (0.2%) on CG electrodes. Surprisingly, our results show that CG can achieve higher current-to-sulfide efficiencies at lower power consumption than the nano-modified three-dimensional MWCNT-RVC. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Reduction of adsorbed As(V) on nano-TiO2 by sulfate-reducing bacteria.

    Science.gov (United States)

    Luo, Ting; Ye, Li; Ding, Cheng; Yan, Jinlong; Jing, Chuanyong

    2017-11-15

    Reduction of surface-bound arsenate [As(V)] and subsequent release into the aqueous phase contribute to elevated As in groundwater. However, this natural process is not fully understood, especially in the presence of sulfate-reducing bacteria (SRB). Gaining mechanistic insights into solid-As(V)-SRB interactions motivated our molecular level study on the fate of nano-TiO2 bound As(V) in the presence of Desulfovibrio vulgaris DP4, a strain of SRB, using incubation and in situ ATR-FTIR experiments. The incubation results clearly revealed the reduction of As(V), either adsorbed on nano-TiO2 or dissolved, in the presence of SRB. In contrast, this As(V) reduction was not observed in abiotic control experiments where sulfide was used as the reductant. Moreover, the reduction was faster for surface-bound As(V) than for dissolved As(V), as evidenced by the appearance of As(III) at 45h and 75h, respectively. ATR-FTIR results provided direct evidence that the surface-bound As(V) was reduced to As(III) on TiO2 surfaces in the presence of SRB. In addition, the As(V) desorption from nano-TiO2 was promoted by SRB relative to abiotic sulfide, due to the competition between As(V) and bacterial phosphate groups for TiO2 surface sites. This competition was corroborated by the ATR-FTIR analysis, which showed inner-sphere surface complex formation by bacterial phosphate groups on TiO2 surfaces. The results from this study highlight the importance of indirect bacteria-mediated As(V) reduction and release in geochemical systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. [Primary study on contents of sulfate reducing bacteria (SRB) and organic matter from intertidal zone at Chongming Dongtan].

    Science.gov (United States)

    Yuan, Qi; Cui, Yu-Xue; Chen, Qing-Qiang; Lü, Bao-Yi; Xie, Bing

    2010-09-01

    Collected soil samples from different tidal flats and elevation in Chongming Dongtan wetland, then conducted sulfate-reducing bacteria (SRB) based on MPN method, determined organic matter content and calculated SO4(2-)/Cl- molar ratio, for the research on the distribution of SRB, relevance to soil organic matter content as well as influence of plant rhizosphere environment on SRB growth. The results show the distribution of SRB is ranked as middle flat > climax flat > bald flat. The same tidal flats at different depths, the SRB levels are shown as 51-52 cm > 21-22 cm > 81-82 cm, therefore 51-52 cm soil depth of Dongtan wetland is the suitable area for SRB to grow. However, in different tidal and depth, the distribution of organic matter content presents climax flat > middle flat > bald flat. From 21-51 cm, as the depth increasing, the organic matter content decreases while the amount of SRB significantly increasing, which indicates SRB utilizes the soil organic matter to carry out reduction reaction. The SO4(2-)/Cl- molar ratios of all soil samples are less than 0.05, indicating that SRB are actively engaged in sulfate reduction. The concentration of SRB in reed rhizosphere soil is the highest, showing that Phragmites australis rhizosphere environment in Dongtan wetland could enhance SRB growth, while the number of SRB in Spartina alterniflora rhizosphere environment is relatively lower than the non-rhizosphere environment, indicating that the rhizosphere effect has different effects on SRB in Dongtan tidal flats.

  10. Estimates of metabolic rate and major constituents of metabolic demand in fishes under field conditions: Methods, proxies, and new perspectives.

    Science.gov (United States)

    Treberg, Jason R; Killen, Shaun S; MacCormack, Tyson J; Lamarre, Simon G; Enders, Eva C

    2016-12-01

    Metabolic costs are central to individual energy budgets, making estimates of metabolic rate vital to understanding how an organism interacts with its environment as well as the role of species in their ecosystem. Despite the ecological and commercial importance of fishes, there are currently no widely adopted means of measuring field metabolic rate in fishes. The lack of recognized methods is in part due to the logistical difficulties of measuring metabolic rates in free swimming fishes. However, further development and refinement of techniques applicable for field-based studies on free swimming animals would greatly enhance the capacity to study fish under environmentally relevant conditions. In an effort to foster discussion in this area, from field ecologists to biochemists alike, we review aspects of energy metabolism and give details on approaches that have been used to estimate energetic parameters in fishes. In some cases, the techniques have been applied to field conditions; while in others, the methods have been primarily used on laboratory held fishes but should be applicable, with validation, to fishes in their natural environment. Limitations, experimental considerations and caveats of these measurements and the study of metabolism in wild fishes in general are also discussed. Potential novel approaches to FMR estimates are also presented for consideration. The innovation of methods for measuring field metabolic rate in free-ranging wild fish would revolutionize the study of physiological ecology. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Characterization of microbial associations with methanotrophic archaea and sulfate-reducing bacteria through statistical comparison of nested Magneto-FISH enrichments

    Directory of Open Access Journals (Sweden)

    Elizabeth Trembath-Reichert

    2016-04-01

    Full Text Available Methane seep systems along continental margins host diverse and dynamic microbial assemblages, sustained in large part through the microbially mediated process of sulfate-coupled Anaerobic Oxidation of Methane (AOM. This methanotrophic metabolism has been linked to consortia of anaerobic methane-oxidizing archaea (ANME and sulfate-reducing bacteria (SRB. These two groups are the focus of numerous studies; however, less is known about the wide diversity of other seep associated microorganisms. We selected a hierarchical set of FISH probes targeting a range of Deltaproteobacteria diversity. Using the Magneto-FISH enrichment technique, we then magnetically captured CARD-FISH hybridized cells and their physically associated microorganisms from a methane seep sediment incubation. DNA from nested Magneto-FISH experiments was analyzed using Illumina tag 16S rRNA gene sequencing (iTag. Enrichment success and potential bias with iTag was evaluated in the context of full-length 16S rRNA gene clone libraries, CARD-FISH, functional gene clone libraries, and iTag mock communities. We determined commonly used Earth Microbiome Project (EMP iTAG primers introduced bias in some common methane seep microbial taxa that reduced the ability to directly compare OTU relative abundances within a sample, but comparison of relative abundances between samples (in nearly all cases and whole community-based analyses were robust. The iTag dataset was subjected to statistical co-occurrence measures of the most abundant OTUs to determine which taxa in this dataset were most correlated across all samples. Many non-canonical microbial partnerships were statistically significant in our co-occurrence network analysis, most of which were not recovered with conventional clone library sequencing, demonstrating the utility of combining Magneto-FISH and iTag sequencing methods for hypothesis generation of associations within complex microbial communities. Network analysis pointed to

  12. Implications from distinct sulfate-reducing bacteria populations between cattle manure and digestate in the elucidation of H2S production during anaerobic digestion of animal slurry.

    Science.gov (United States)

    St-Pierre, Benoit; Wright, André-Denis G

    2017-07-01

    Biogas produced from the anaerobic digestion of animal slurry consists mainly of methane (CH4) and carbon dioxide (CO2), but also includes other minor gases, such as hydrogen sulfide (H2S). Since it can act as a potent corrosive agent and presents a health hazard even at low concentrations, H2S is considered an undesirable by-product of anaerobic digestion. Sulfate-reducing bacteria (SRBs) have been identified as the main biological source of H2S in a number of natural, biological, and human-made habitats, and thus represent likely candidate microorganisms responsible for the production of H2S in anaerobic manure digesters. Phylogenetically, SRBs form a divergent group of bacteria that share a common anaerobic respiration pathway that allows them to use sulfate as a terminal electron acceptor. While the composition and activity of SRBs have been well documented in other environments, their metabolic potential remains largely uncharacterized and their populations poorly defined in anaerobic manure digesters. In this context, a combination of in vitro culture-based studies and DNA-based approaches, respectively, were used to gain further insight. Unexpectedly, only low to nondetectable levels of H2S were produced by digestate collected from a manure biogas plant documented to have persistently high concentrations of H2S in its biogas (2000-3000 ppm). In contrast, combining digestate with untreated manure (a substrate with comparatively lower sulfate and SRB cell densities than digestate) was found to produce elevated H2S levels in culture. While a 16S rRNA gene-based community composition approach did not reveal likely candidate SRBs in digestate or untreated manure, the use of the dsrAB gene as a phylogenetic marker provided more insight. In digestate, the predominant SRBs were found to be uncharacterized species likely belonging to the genus Desulfosporosinus (Peptococcaceae, Clostridiales, Firmicutes), while Desulfovibrio-related SRBs (Desulfovibrionaceae

  13. Impact of Iron Metabolic Disturbances on Hemostasis in Critical Conditions

    Directory of Open Access Journals (Sweden)

    Yu. P. Orlov

    2007-01-01

    Full Text Available Objective: To determine the regularities of iron metabolic disturbances and their impact on the hemostatic system in critically ill patients due to the severe course of generalized purulent peritonitis, acute pancreatitis, and thermal skin injuries. Materials and methods. In 36 patients with an APACHE II of 22.6±3.4 scores, endogenous iron metabolism was assessed by the level of serum iron, total serum syderopexy power, transferrin iron accumulation, ferritin concentrations, and free hemoglobin levels in blood; the antioxidative protective system, lipid peroxidation activity, and hemostatic parameters are studied. Results. There are general regularities in the hemostatic influence of the high concentrations of free hemoglobin and free radical oxidation products in critically ill patients due to generalized peritonitis, acute pancreatitis, or thermal skin injuries. In these patients, iron metabolism occurs with the overload of transporter proteins, such as transferrin and ferritin. Conclusion. Microcirculatory disorders as intravascular hemolysis and hemoglobin metabolism to ionized iron activate lipid peroxidation in the presence of excess Fe2+, which favors strain of the hemostatic system, by determining a tendency toward hypo- or hypercoagulation via the lowered activity of the platelets dependent on the state of free radical processes. Key words: ionized iron, transferrin, ferritin, lipid peroxidation, intravascular hemolysis, hemostasis.

  14. The Sulfate-Rich and Extreme Saline Sediment of the Ephemeral Tirez Lagoon: A Biotope for Acetoclastic Sulfate-Reducing Bacteria and Hydrogenotrophic Methanogenic Archaea

    OpenAIRE

    Montoya, Lilia; Lozada-Chávez, Irma; Amils, Ricardo; Rodríguez, Nuria; Marín, Irma

    2011-01-01

    Our goal was to examine the composition of methanogenic archaea (MA) and sulfate-reducing (SRP) and sulfur-oxidizing (SOP) prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain). Thus, adenosine-5-phosphosulfate (APS) reductase α (aprA) and methyl coenzyme M reductase α (mcrA) gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and d...

  15. The Sulfate-Rich and Extreme Saline Sediment of the Ephemeral Tirez Lagoon: A Biotope for Acetoclastic Sulfate-Reducing Bacteria and Hydrogenotrophic Methanogenic Archaea

    OpenAIRE

    Lilia Montoya; Irma Lozada-Chávez; Ricardo Amils; Nuria Rodriguez; Irma Marín

    2011-01-01

    Our goal was to examine the composition of methanogenic archaea (MA) and sulfate-reducing (SRP) and sulfur-oxidizing (SOP) prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain). Thus, adenosine- 5 ′ -phosphosulfate (APS) reductase (aprA) and methyl coenzyme M reductase α (mcrA) gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and ...

  16. A coupled metabolic-hydraulic model and calibration scheme for estimating of whole-river metabolism during dynamic flow conditions

    Science.gov (United States)

    Payn, Robert A.; Hall, Robert O Jr.; Kennedy, Theodore; Poole, Geoff C; Marshall, Lucy A.

    2017-01-01

    Conventional methods for estimating whole-stream metabolic rates from measured dissolved oxygen dynamics do not account for the variation in solute transport times created by dynamic flow conditions. Changes in flow at hourly time scales are common downstream of hydroelectric dams (i.e. hydropeaking), and hydrologic limitations of conventional metabolic models have resulted in a poor understanding of the controls on biological production in these highly managed river ecosystems. To overcome these limitations, we coupled a two-station metabolic model of dissolved oxygen dynamics with a hydrologic river routing model. We designed calibration and parameter estimation tools to infer values for hydrologic and metabolic parameters based on time series of water quality data, achieving the ultimate goal of estimating whole-river gross primary production and ecosystem respiration during dynamic flow conditions. Our case study data for model design and calibration were collected in the tailwater of Glen Canyon Dam (Arizona, USA), a large hydropower facility where the mean discharge was 325 m3 s 1 and the average daily coefficient of variation of flow was 0.17 (i.e. the hydropeaking index averaged from 2006 to 2016). We demonstrate the coupled model’s conceptual consistency with conventional models during steady flow conditions, and illustrate the potential bias in metabolism estimates with conventional models during unsteady flow conditions. This effort contributes an approach to solute transport modeling and parameter estimation that allows study of whole-ecosystem metabolic regimes across a more diverse range of hydrologic conditions commonly encountered in streams and rivers.

  17. Mapping the Arabidopsis Metabolic Landscape by Untargeted Metabolomics at Different Environmental Conditions

    NARCIS (Netherlands)

    Wu, Si; Tohge, Takayuki; Cuadros-Inostroza, Álvaro; Tong, Hao; Tenenboim, Hezi; Kooke, Rik; Méret, Michaël; Keurentjes, Joost B.; Nikoloski, Zoran; Fernie, Alisdair Robert; Willmitzer, Lothar; Brotman, Yariv

    2018-01-01

    Metabolic genome-wide association studies (mGWAS), whereupon metabolite levels are regarded as traits, can help unravel the genetic basis of metabolic networks. A total of 309 Arabidopsis accessions were grown under two independent environmental conditions (control and stress) and subjected to

  18. Individuals exhibit consistent differences in their metabolic rates across changing thermal conditions.

    Science.gov (United States)

    Auer, Sonya K; Salin, Karine; Anderson, Graeme J; Metcalfe, Neil B

    2018-03-01

    Metabolic rate has been linked to growth, reproduction, and survival at the individual level and is thought to have far reaching consequences for the ecology and evolution of organisms. However, metabolic rates must be consistent (i.e. repeatable) over at least some portion of the lifetime in order to predict their longer-term effects on population dynamics and how they will respond to selection. Previous studies demonstrate that metabolic rates are repeatable under constant conditions but potentially less so in more variable environments. We measured the standard (=minimum) metabolic rate, maximum metabolic rate, and aerobic scope (=interval between standard and maximum rates) in juvenile brown trout (Salmo trutta) after 5weeks acclimation to each of three consecutive test temperatures (10, 13, and then 16°C) that simulated the warming conditions experienced throughout their first summer of growth. We found that metabolic rates are repeatable over a period of months under changing thermal conditions: individual trout exhibited consistent differences in all three metabolic traits across increasing temperatures. Initial among-individual differences in metabolism are thus likely to have significant consequences for fitness-related traits over key periods of their life history. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Bariatric surgery for obesity and metabolic conditions in adults.

    Science.gov (United States)

    Arterburn, David E; Courcoulas, Anita P

    2014-08-27

    This review summarizes recent evidence related to the safety, efficacy, and metabolic outcomes of bariatric surgery to guide clinical decision making. Several short term randomized controlled trials have demonstrated the effectiveness of bariatric procedures for inducing weight loss and initial remission of type 2 diabetes. Observational studies have linked bariatric procedures with long term improvements in body weight, type 2 diabetes, survival, cardiovascular events, incident cancer, and quality of life. Perioperative mortality for the average patient is low but varies greatly across subgroups. The incidence of major complications after surgery also varies widely, and emerging data show that some procedures are associated with a greater risk of substance misuse disorders, suicide, and nutritional deficiencies. More research is needed to enable long term outcomes to be compared across various procedures and subpopulations, and to identify those most likely to benefit from surgical intervention. Given uncertainties about the balance between the risks and benefits of bariatric surgery in the long term, the decision to undergo surgery should be based on a high quality shared decision making process. © BMJ Publishing Group Ltd 2014.

  20. Global test for metabolic pathway differences between conditions.

    NARCIS (Netherlands)

    Hendrickx, D.M.; Hoefsloot, H.C.J.; Hendriks, M.M.W.B.; Canelas, A.B.; Smilde, A.K.

    2012-01-01

    In many metabolomics applications there is a need to compare metabolite levels between different conditions, e.g., case versus control. There exist many statistical methods to perform such comparisons but only few of these explicitly take into account the fact that metabolites are connected in

  1. Backtest type and housing condition of pigs influence energy metabolism

    NARCIS (Netherlands)

    Geverink, N.A.; Heetkamp, M.J.W.; Schouten, W.G.P.; Wiegant, V.M.; Schrama, J.W.

    2004-01-01

    The behavioral response of piglets in a backtest early in life seems indicative of their coping strategy at a later age. Coping characteristics may depend on the interaction between backtest classification and housing conditions. We studied whether growth rate and partitioning of energy in adult

  2. Mapping condition-dependent regulation of metabolism in yeast through genome-scale modeling

    DEFF Research Database (Denmark)

    Österlund, Tobias; Nookaew, Intawat; Bordel, Sergio

    2013-01-01

    ABSTRACT: BACKGROUND: The genome-scale metabolic model of Saccharomyces cerevisiae, first presented in 2003, was the first genome-scale network reconstruction for a eukaryotic organism. Since then continuous efforts have been made in order to improve and expand the yeast metabolic network. RESULTS......-filling methods and by introducing new reactions and pathways based on studies of the literature and databases. The model was shown to perform well both for growth simulations in different media and gene essentiality analysis for single and double knock-outs. Further, the model was used as a scaffold......-to-date collection of knowledge on yeast metabolism. The model was used for simulating the yeast metabolism under four different growth conditions and experimental data from these four conditions was integrated to the model. The model together with experimental data is a useful tool to identify condition...

  3. Molecular Analysis of the Diversity of Sulfate-Reducing and Sulfur-Oxidizing Prokaryotes in the Environment, Using aprA as Functional Marker Gene▿ †

    Science.gov (United States)

    Meyer, Birte; Kuever, Jan

    2007-01-01

    The dissimilatory adenosine-5′-phosposulfate reductase is a key enzyme of the microbial sulfate reduction and sulfur oxidation processes. Because the alpha- and beta-subunit-encoding genes, aprBA, are highly conserved among sulfate-reducing and sulfur-oxidizing prokaryotes, they are most suitable for molecular profiling of the microbial community structure of the sulfur cycle in environment. In this study, a new aprA gene-targeting assay using a combination of PCR and denaturing gradient gel electrophoresis is presented. The screening of sulfate-reducing and sulfur-oxidizing reference strains as well as the analyses of environmental DNA from diverse habitats (e.g., microbial mats, invertebrate tissue, marine and estuarine sediments, and filtered hydrothermal water) by the new primer pair revealed an improved microbial diversity coverage and less-pronounced template-to-PCR product bias in direct comparison to those of the previously published primer set (B. Deplancke, K. R. Hristova, H. A. Oakley, V. J. McCracken, R. Aminov, R. I. Mackie, and H. R. Gaskins, Appl. Environ. Microbiol. 66:2166-2174, 2000). The concomitant molecular detection of sulfate-reducing and sulfur-oxidizing prokaryotes was confirmed. The new assay was applied in comparison with the 16S rRNA gene-based analysis to investigate the microbial diversity of the sulfur cycle in sediment, seawater, and manganese crust samples from four study sites in the area of the Lesser Antilles volcanic arc, Caribbean Sea (Caribflux project). The aprA gene-based approach revealed putative sulfur-oxidizing Alphaproteobacteria of chemolithoheterotrophic lifestyle to have been abundant in the nonhydrothermal sediment and water column. In contrast, the sulfur-based microbial community that inhabited the surface of the volcanic manganese crust was more complex, consisting predominantly of putative chemolithoautotrophic sulfur oxidizers of the Betaproteobacteria and Gammaproteobacteria. PMID:17921272

  4. Molecular analysis of the diversity of sulfate-reducing and sulfur-oxidizing prokaryotes in the environment, using aprA as functional marker gene.

    Science.gov (United States)

    Meyer, Birte; Kuever, Jan

    2007-12-01

    The dissimilatory adenosine-5'-phosphosulfate reductase is a key enzyme of the microbial sulfate reduction and sulfur oxidation processes. Because the alpha- and beta-subunit-encoding genes, aprBA, are highly conserved among sulfate-reducing and sulfur-oxidizing prokaryotes, they are most suitable for molecular profiling of the microbial community structure of the sulfur cycle in environment. In this study, a new aprA gene-targeting assay using a combination of PCR and denaturing gradient gel electrophoresis is presented. The screening of sulfate-reducing and sulfur-oxidizing reference strains as well as the analyses of environmental DNA from diverse habitats (e.g., microbial mats, invertebrate tissue, marine and estuarine sediments, and filtered hydrothermal water) by the new primer pair revealed an improved microbial diversity coverage and less-pronounced template-to-PCR product bias in direct comparison to those of the previously published primer set (B. Deplancke, K. R. Hristova, H. A. Oakley, V. J. McCracken, R. Aminov, R. I. Mackie, and H. R. Gaskins, Appl. Environ. Microbiol. 66:2166-2174, 2000). The concomitant molecular detection of sulfate-reducing and sulfur-oxidizing prokaryotes was confirmed. The new assay was applied in comparison with the 16S rRNA gene-based analysis to investigate the microbial diversity of the sulfur cycle in sediment, seawater, and manganese crust samples from four study sites in the area of the Lesser Antilles volcanic arc, Caribbean Sea (Caribflux project). The aprA gene-based approach revealed putative sulfur-oxidizing Alphaproteobacteria of chemolithoheterotrophic lifestyle to have been abundant in the nonhydrothermal sediment and water column. In contrast, the sulfur-based microbial community that inhabited the surface of the volcanic manganese crust was more complex, consisting predominantly of putative chemolithoautotrophic sulfur oxidizers of the Betaproteobacteria and Gammaproteobacteria.

  5. Interactions between sleep, stress, and metabolism: From physiological to pathological conditions

    Directory of Open Access Journals (Sweden)

    Camila Hirotsu

    2015-11-01

    Full Text Available Poor sleep quality due to sleep disorders and sleep loss is highly prevalent in the modern society. Underlying mechanisms show that stress is involved in the relationship between sleep and metabolism through hypothalamic–pituitary–adrenal (HPA axis activation. Sleep deprivation and sleep disorders are associated with maladaptive changes in the HPA axis, leading to neuroendocrine dysregulation. Excess of glucocorticoids increase glucose and insulin and decrease adiponectin levels. Thus, this review provides overall view of the relationship between sleep, stress, and metabolism from basic physiology to pathological conditions, highlighting effective treatments for metabolic disturbances.

  6. GIM3E: Condition-specific Models of Cellular Metabolism Developed from Metabolomics and Expression Data

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Brian; Ebrahim, Ali; Metz, Thomas O.; Adkins, Joshua N.; Palsson, Bernard O.; Hyduke, Daniel R.

    2013-11-15

    Motivation: Genome-scale metabolic models have been used extensively to investigate alterations in cellular metabolism. The accuracy of these models to represent cellular metabolism in specific conditions has been improved by constraining the model with omics data sources. However, few practical methods for integrating metabolomics data with other omics data sources into genome-scale models of metabolism have been reported. Results: GIMMME (Gene Inactivation Moderated by Metabolism, Metabolomics, and Expression) is an algorithm that enables the development of condition-specific models based on an objective function, transcriptomics, and intracellular metabolomics data. GIMMME establishes metabolite utilization requirements with metabolomics data, uses model-paired transcriptomics data to find experimentally supported solutions, and also provides calculations of the turnover (production / consumption) flux of metabolites. GIMMME was employed to investigate the effects of integrating additional omics datasets to create increasingly constrained solution spaces of Salmonella Typhimurium metabolism during growth in both rich and virulence media. This integration proved to be informative and resulted in a requirement of additional active reactions (12 in each case) or metabolites (26 or 29, respectively). The addition of constraints from transcriptomics also impacted the allowed solution space, and the cellular metabolites with turnover fluxes that were necessarily altered by the change in conditions increased from 118 to 271 of 1397. Availability: GIMMME has been implemented in Python and requires a COBRApy 0.2.x. The algorithm and sample data described here are freely available at: http://opencobra.sourceforge.net/

  7. GIM3E: condition-specific models of cellular metabolism developed from metabolomics and expression data.

    Science.gov (United States)

    Schmidt, Brian J; Ebrahim, Ali; Metz, Thomas O; Adkins, Joshua N; Palsson, Bernhard Ø; Hyduke, Daniel R

    2013-11-15

    Genome-scale metabolic models have been used extensively to investigate alterations in cellular metabolism. The accuracy of these models to represent cellular metabolism in specific conditions has been improved by constraining the model with omics data sources. However, few practical methods for integrating metabolomics data with other omics data sources into genome-scale models of metabolism have been developed. GIM(3)E (Gene Inactivation Moderated by Metabolism, Metabolomics and Expression) is an algorithm that enables the development of condition-specific models based on an objective function, transcriptomics and cellular metabolomics data. GIM(3)E establishes metabolite use requirements with metabolomics data, uses model-paired transcriptomics data to find experimentally supported solutions and provides calculations of the turnover (production/consumption) flux of metabolites. GIM(3)E was used to investigate the effects of integrating additional omics datasets to create increasingly constrained solution spaces of Salmonella Typhimurium metabolism during growth in both rich and virulence media. This integration proved to be informative and resulted in a requirement of additional active reactions (12 in each case) or metabolites (26 or 29, respectively). The addition of constraints from transcriptomics also impacted the allowed solution space, and the cellular metabolites with turnover fluxes that were necessarily altered by the change in conditions increased from 118 to 271 of 1397. GIM(3)E has been implemented in Python and requires a COBRApy 0.2.x. The algorithm and sample data described here are freely available at: http://opencobra.sourceforge.net/ brianjamesschmidt@gmail.com

  8. Mercury methylation in Sphagnum moss mats and its association with sulfate-reducing bacteria in an acidic Adirondack forest lake wetland.

    Science.gov (United States)

    Yu, Ri-Qing; Adatto, Isaac; Montesdeoca, Mario R; Driscoll, Charles T; Hines, Mark E; Barkay, Tamar

    2010-12-01

    Processes leading to the bioaccumulation of methylmercury (MeHg) in northern wetlands are largely unknown. We have studied various ecological niches within a remote, acidic forested lake ecosystem in the southwestern Adirondacks, NY, to discover that mats comprised of Sphagnum moss were a hot spot for mercury (Hg) and MeHg accumulation (190.5 and 18.6 ng g⁻¹ dw, respectively). Furthermore, significantly higher potential methylation rates were measured in Sphagnum mats as compared with other sites within Sunday Lake's ecosystem. Although MPN estimates showed a low biomass of sulfate-reducing bacteria (SRB), 2.8 × 10⁴ cells mL⁻¹ in mat samples, evidence consisting of (1) a twofold stimulation of potential methylation by the addition of sulfate, (2) a significant decrease in Hg methylation in the presence of the sulfate reduction inhibitor molybdate, and (3) presence of dsrAB-like genes in mat DNA extracts, suggested that SRB were involved in Hg methylation. Sequencing of dsrB genes indicated that novel SRB, incomplete oxidizers including Desulfobulbus spp. and Desulfovibrio spp., and syntrophs dominated the sulfate-reducing guild in the Sphagnum moss mat. Sphagnum, a bryophyte dominating boreal peatlands, and its associated microbial communities appear to play an important role in the production and accumulation of MeHg in high-latitude ecosystems. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. Mapping Condition-Dependent Regulation of Lipid Metabolism in Saccharomyces cerevisiae

    Science.gov (United States)

    Jewett, Michael C.; Workman, Christopher T.; Nookaew, Intawat; Pizarro, Francisco A.; Agosin, Eduardo; Hellgren, Lars I.; Nielsen, Jens

    2013-01-01

    Lipids play a central role in cellular function as constituents of membranes, as signaling molecules, and as storage materials. Although much is known about the role of lipids in regulating specific steps of metabolism, comprehensive studies integrating genome-wide expression data, metabolite levels, and lipid levels are currently lacking. Here, we map condition-dependent regulation controlling lipid metabolism in Saccharomyces cerevisiae by measuring 5636 mRNAs, 50 metabolites, 97 lipids, and 57 13C-reaction fluxes in yeast using a three-factor full-factorial design. Correlation analysis across eight environmental conditions revealed 2279 gene expression level-metabolite/lipid relationships that characterize the extent of transcriptional regulation in lipid metabolism relative to major metabolic hubs within the cell. To query this network, we developed integrative methods for correlation of multi-omics datasets that elucidate global regulatory signatures. Our data highlight many characterized regulators of lipid metabolism and reveal that sterols are regulated more at the transcriptional level than are amino acids. Beyond providing insights into the systems-level organization of lipid metabolism, we anticipate that our dataset and approach can join an emerging number of studies to be widely used for interrogating cellular systems through the combination of mathematical modeling and experimental biology. PMID:24062529

  10. Acetobacter pasteurianus metabolic change induced by initial acetic acid to adapt to acetic acid fermentation conditions.

    Science.gov (United States)

    Zheng, Yu; Zhang, Renkuan; Yin, Haisong; Bai, Xiaolei; Chang, Yangang; Xia, Menglei; Wang, Min

    2017-09-01

    Initial acetic acid can improve the ethanol oxidation rate of acetic acid bacteria for acetic acid fermentation. In this work, Acetobacter pasteurianus was cultured in ethanol-free medium, and energy production was found to increase by 150% through glucose consumption induced by initial acetic acid. However, oxidation of ethanol, instead of glucose, became the main energy production pathway when upon culturing ethanol containing medium. Proteome assay was used to analyze the metabolism change induced by initial acetic acid, which provided insight into carbon metabolic and energy regulation of A. pasteurianus to adapt to acetic acid fermentation conditions. Results were further confirmed by quantitative real-time PCR. In summary, decreased intracellular ATP as a result of initial acetic acid inhibition improved the energy metabolism to produce more energy and thus adapt to the acetic acid fermentation conditions. A. pasteurianus upregulated the expression of enzymes related to TCA and ethanol oxidation to improve the energy metabolism pathway upon the addition of initial acetic acid. However, enzymes involved in the pentose phosphate pathway, the main pathway of glucose metabolism, were downregulated to induce a change in carbon metabolism. Additionally, the enhancement of alcohol dehydrogenase expression promoted ethanol oxidation and strengthened the acetification rate, thereby producing a strong proton motive force that was necessary for energy production and cell tolerance to acetic acid.

  11. Distinct age and differentiation-state dependent metabolic profiles of oligodendrocytes under optimal and stress conditions.

    Directory of Open Access Journals (Sweden)

    Vijayaraghava T S Rao

    Full Text Available Within the microenvironment of multiple sclerosis lesions, oligodendrocytes are subject to metabolic stress reflecting effects of focal ischemia and inflammation. Previous studies have shown that under optimal conditions in vitro, the respiratory activity of human adult brain-derived oligodendrocytes is lower and more predominantly glycolytic compared to oligodendrocytes differentiated in vitro from post natal rat brain oligodendrocyte progenitor cells. In response to sub-lethal metabolic stress, adult human oligodendrocytes reduce overall energy production rate impacting the capacity to maintain myelination. Here, we directly compare the metabolic profiles of oligodendrocytes derived from adult rat brain with oligodendrocytes newly differentiated in vitro from oligodendrocyte progenitor cells obtained from the post natal rat brain, under both optimal culture and metabolic stress (low/no glucose conditions. Oxygen consumption and extracellular acidification rates were measured using a Seahorse extracellular flux analyzer. Our findings indicate that under optimal conditions, adult rat oligodendrocytes preferentially use glycolysis whereas newly differentiated post natal rat oligodendrocytes, and the oligodendrocyte progenitor cells from which they are derived, mainly utilize oxidative phosphorylation to produce ATP. Metabolic stress increases the rate of ATP production via oxidative phosphorylation and significantly reduces glycolysis in adult oligodendrocytes. The rate of ATP production was relatively unchanged in newly differentiated post natal oligodendrocytes under these stress conditions, while it was significantly reduced in oligodendrocyte progenitor cells. Our study indicates that both age and maturation influence the metabolic profile under optimal and stressed conditions, emphasizing the need to consider these variables for in vitro studies that aim to model adult human disease.

  12. In Vitro Disease Model of Microgravity Conditioning on Human Energy Metabolism

    Science.gov (United States)

    Snyder, Jessica; Culbertson, C.; Zhang, Ye; Emami, K.; Wu, H.; Sun, Wei

    2010-01-01

    NASA and its partners are committed to introducing appropriate new technology to enable learning and living safely beyond the Earth for extended periods of time in a sustainable and possibly indefinite manner. In the responsible acquisition of that goal, life sciences is tasked to tune and advance current medical technology to prepare for human health and wellness in the space environment. The space environment affects the condition and function of biological systems from organ level function to shape of individual organelles. The objective of this paper is to study the effect of microgravity on kinetics of drug metabolism. This fundamental characterization is meaningful to (1) scientific understanding of the response of biology to microgravity and (2) clinical dosing requirements and pharmacological thresholds during long term manned space exploration. Metabolism kinetics of the anti-nausea drug promethazine (PMZ) were determined by an in vitro ground model of 3-dimensional aggregates of human hepatocytes conditioned to weightlessness using a rotating wall bioreactor. The authors observed up-regulated PMZ conversion in model microgravity conditions and attribute this to effect to model microgravity conditioning acting on metabolic mechanisms of the cells. Further work is necessary to determine which particular cellular mechanisms are governing the experimental observations, but the authors conclude kinetics of drug metabolism are responsive to gravitational fields and further study of this sensitivity would improve dosing of pharmaceuticals to persons exposed to a microgravity environment.

  13. Mapping Condition-Dependent Regulation of Lipid Metabolism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Jewett, Michael Christopher; Workman, Christopher; Nookaew, Intawat

    2013-01-01

    levels, and lipid levels are currently lacking. Here, we map condition-dependent regulation controlling lipid metabolism in Saccharomyces cerevisiae by measuring 5636 mRNAs, 50 metabolites, 97 lipids, and 57 13C-reaction fluxes in yeast using a three-factor full-factorial design. Correlation analysis...

  14. Metabolic Myopathies

    Science.gov (United States)

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

  15. The impact of temperature change on the activity and community composition of sulfate-reducing bacteria in arctic versus temperate marine sediments

    DEFF Research Database (Denmark)

    Robador, Alberto; Brüchert, Volker; Jørgensen, Bo Barker

    2009-01-01

    -reducing bacteria (SRB). However, high rates at in situ temperatures compared with maximum rates showed the predominance of psychrophilic SRB even at high incubation temperatures. Changing apparent activation energies (Ea) showed that increasing temperatures had an initial negative impact on sulfate reduction...... that was weaker after prolonged incubations, which could imply an acclimatization response rather than a selection process of the SRB community. The microbial community composition was analysed by targeting the 16S ribosomal RNA using catalysed reporter deposition fluorescence in situ hybridization (CARD......-FISH). The results showed the decline of specific groups of SRB and confirmed a strong impact of increasing temperatures on the microbial community composition of arctic sediment. Conversely, in seasonally changing sediment sulfate reduction rates and sulfate-reducing bacterial abundance changed little in response...

  16. Effect of nitrate addition on prokaryotic diversity and the activity of sulfate-reducing prokaryotes in high-temperature oil production systems

    DEFF Research Database (Denmark)

    Gittel, Antje; Wieczorek, Adam; Sørensen, Ketil

    Adding nitrate to injection water is a possible strategy to control the activity of sulfate-reducing prokaryotes (SRP) in oil production system. To assess the effects of nitrate addition, prokaryotic diversity (Bacteria, Archaea, SRP) and SRP activity were studied in the production waters...... of a nitrate-treated and a non-treated system. Comparative analyses of clone libraries indicated that troublesome prokaryotes were enriched at the non-treated site represented by both sulfate- and sulfur-reducing prokaryotes within the Bacteria (Deltaproteobacteria, Desulfotomaculum spp.) and Archaea...... inhibited by nitrate addition. Visualization and quantification of the identified troublesome prokaryotes and potential competitors using the CARD-FISH technique will be performed on production water from both sites....

  17. Metabolic and functional phenotypic profiling of Drosophila melanogaster reveals reduced sex differentiation under stressful environmental conditions

    DEFF Research Database (Denmark)

    Ørsted, Michael; Malmendal, Anders; Muñoz, Joaquin

    2017-01-01

    Strong sexual dimorphism is commonly observed across species and e.g. trade-offs between reproduction and maintenance are thought to explain this dimorphism. Here we test how the metabolic and functional phenotypic responses to varying types of environmental stress differ in male and female...... rearing regimes were investigated using NMR metabolomics and assessed for body mass and viability. Our results showed that environmental stress leads to reduced sexual dimorphism in both metabolic composition and body mass compared to the level of dimorphism observed at benign conditions. This reduced...

  18. The membrane QmoABC complex interacts directly with the dissimilatory adenosine 5´-phosphosulfate reductase in sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    Ana Raquel Ramos

    2012-04-01

    Full Text Available The adenosine 5’-phosphosulfate reductase (AprAB is the enzyme responsible for the reduction of adenosine 5’-phosphosulfate (APS to sulfite in the biological process of dissimilatory sulfate reduction, which is carried out by a ubiquitous group of sulfate reducing prokaryotes. The electron donor for AprAB has not been clearly identified, but was proposed to be the QmoABC membrane complex, since an aprBA-qmoABC gene cluster is found in many sulfate-reducing and sulfur-oxidising bacteria. The QmoABC complex is essential for sulfate reduction, but electron transfer between QmoABC and AprAB has not been reported. In this work we provide the first direct evidence that QmoABC and AprAB interact in Desulfovibrio spp., using co-immunoprecipitation, cross-linking Far-Western blot, tag-affinity purification and surface plasmon resonance studies. This showed that the QmoABC-AprAB complex has a strong steady-state affinity (KD = 90 ± 3 nM, but has a transient character due to a fast dissociation rate. Far-Western blot identified QmoA as the Qmo subunit most involved in the interaction. Nevertheless, electron transfer from menaquinol analogues to APS through anaerobically purified QmoABC and AprAB could not be detected. We propose that this reaction requires the involvement of a third partner to allow electron flow driven by a reverse electron bifurcation process i.e. electron confurcation. This process is deemed essential to allow coupling of APS reduction to chemiosmotic energy conservation.

  19. Altered Clock and Lipid Metabolism-Related Genes in Atherosclerotic Mice Kept with Abnormal Lighting Condition

    Directory of Open Access Journals (Sweden)

    Zhu Zhu

    2016-01-01

    Full Text Available Background. The risk of atherosclerosis is elevated in abnormal lipid metabolism and circadian rhythm disorder. We investigated whether abnormal lighting condition would have influenced the circadian expression of clock genes and clock-controlled lipid metabolism-related genes in ApoE-KO mice. Methods. A mouse model of atherosclerosis with circadian clock genes expression disorder was established using ApoE-KO mice (ApoE-KO LD/DL mice by altering exposure to light. C57 BL/6J mice (C57 mice and ApoE-KO mice (ApoE-KO mice exposed to normal day and night and normal diet served as control mice. According to zeitgeber time samples were acquired, to test atheromatous plaque formation, serum lipids levels and rhythmicity, clock genes, and lipid metabolism-related genes along with Sirtuin 1 (Sirt1 levels and rhythmicity. Results. Atherosclerosis plaques were formed in the aortic arch of ApoE-KO LD/DL mice. The serum lipids levels and oscillations in ApoE-KO LD/DL mice were altered, along with the levels and diurnal oscillations of circadian genes, lipid metabolism-associated genes, and Sirt1 compared with the control mice. Conclusions. Abnormal exposure to light aggravated plaque formation and exacerbated disorders of serum lipids and clock genes, lipid metabolism genes and Sirt1 levels, and circadian oscillation.

  20. Thermal biology of flight in a butterfly: genotype, flight metabolism, and environmental conditions.

    Science.gov (United States)

    Mattila, Anniina L K

    2015-12-01

    Knowledge of the effects of thermal conditions on animal movement and dispersal is necessary for a mechanistic understanding of the consequences of climate change and habitat fragmentation. In particular, the flight of ectothermic insects such as small butterflies is greatly influenced by ambient temperature. Here, variation in body temperature during flight is investigated in an ecological model species, the Glanville fritillary butterfly (Melitaea cinxia). Attention is paid on the effects of flight metabolism, genotypes at candidate loci, and environmental conditions. Measurements were made under a natural range of conditions using infrared thermal imaging. Heating of flight muscles by flight metabolism has been presumed to be negligible in small butterflies. However, the results demonstrate that Glanville fritillary males with high flight metabolic rate maintain elevated body temperature better during flight than males with a low rate of flight metabolism. This effect is likely to have a significant influence on the dispersal performance and fitness of butterflies and demonstrates the possible importance of intraspecific physiological variation on dispersal in other similar ectothermic insects. The results also suggest that individuals having an advantage in low ambient temperatures can be susceptible to overheating at high temperatures. Further, tolerance of high temperatures may be important for flight performance, as indicated by an association of heat-shock protein (Hsp70) genotype with flight metabolic rate and body temperature at takeoff. The dynamics of body temperature at flight and factors affecting it also differed significantly between female and male butterflies, indicating that thermal dynamics are governed by different mechanisms in the two sexes. This study contributes to knowledge about factors affecting intraspecific variation in dispersal-related thermal performance in butterflies and other insects. Such information is needed for predictive

  1. Dynamic Succession of Groundwater Sulfate-Reducing Communities during Prolonged Reduction of Uranium in a Contaminated Aquifer.

    Science.gov (United States)

    Zhang, Ping; He, Zhili; Van Nostrand, Joy D; Qin, Yujia; Deng, Ye; Wu, Liyou; Tu, Qichao; Wang, Jianjun; Schadt, Christopher W; W Fields, Matthew; Hazen, Terry C; Arkin, Adam P; Stahl, David A; Zhou, Jizhong

    2017-04-04

    To further understand the diversity and dynamics of SRB in response to substrate amendment, we sequenced genes coding for the dissimilatory sulfite reductase (dsrA) in groundwater samples collected after an emulsified vegetable oil (EVO) amendment, which sustained U(VI)-reducing conditions for one year in a fast-flowing aquifer. EVO amendment significantly altered the composition of groundwater SRB communities. Sequences having no closely related-described species dominated (80%) the indigenous SRB communities in nonamended wells. After EVO amendment, Desulfococcus, Desulfobacterium, and Desulfovibrio, known for long-chain-fatty-acid, short-chain-fatty-acid and H2 oxidation and U(VI) reduction, became dominant accounting for 7 ± 2%, 21 ± 8%, and 55 ± 8% of the SRB communities, respectively. Succession of these SRB at different bioactivity stages based on redox substrates/products (acetate, SO4-2, U(VI), NO3-, Fe(II), and Mn(II)) was observed. Desulfovibrio and Desulfococcus dominated SRB communities at 4-31 days, whereas Desulfobacterium became dominant at 80-140 days. By the end of the experiment (day 269), the abundance of these SRB decreased but the overall diversity of groundwater SRB was still higher than non-EVO controls. Up to 62% of the SRB community changes could be explained by groundwater geochemical variables, including those redox substrates/products. A significant (P SRB and their dynamics were correlated significantly with slow EVO biodegradation, electron donor production and maintenance of U(VI)-reducing conditions in the aquifer.

  2. Dynamic Succession of Groundwater Sulfate-Reducing Communities during Prolonged Reduction of Uranium in a Contaminated Aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ping [Univ. of Oklahoma, Norman, OK (United States); He, Zhili [Univ. of Oklahoma, Norman, OK (United States); Van Nostrand, Joy D. [Univ. of Oklahoma, Norman, OK (United States); Qin, Yujia [Univ. of Oklahoma, Norman, OK (United States); Deng, Ye [Univ. of Oklahoma, Norman, OK (United States); Chinese Academy of Sciences (CAS), Beijing (China); Wu, Liyou [Univ. of Oklahoma, Norman, OK (United States); Tu, Qichao [Univ. of Oklahoma, Norman, OK (United States); Zhejiang Univ., Hangzhou (China); Wang, Jianjun [Univ. of Oklahoma, Norman, OK (United States); Chinese Academy of Sciences (CAS), Nanjing (China); Schadt, Christopher W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); W. Fields, Matthew [Montana State Univ., Bozeman, MT (United States); Hazen, Terry C. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Arkin, Adam P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Stahl, David A. [Univ. of Washington, Seattle, WA (United States); Zhou, Jizhong [Univ. of Oklahoma, Norman, OK (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsinghua Univ., Beijing (China)

    2017-03-16

    To further understand the diversity and dynamics of SRB in response to substrate amendment, we sequenced in this paper genes coding for the dissimilatory sulfite reductase (dsrA) in groundwater samples collected after an emulsified vegetable oil (EVO) amendment, which sustained U(VI)-reducing conditions for one year in a fast-flowing aquifer. EVO amendment significantly altered the composition of groundwater SRB communities. Sequences having no closely related-described species dominated (80%) the indigenous SRB communities in nonamended wells. After EVO amendment, Desulfococcus, Desulfobacterium, and Desulfovibrio, known for long-chain-fatty-acid, short-chain-fatty-acid and H2 oxidation and U(VI) reduction, became dominant accounting for 7 ± 2%, 21 ± 8%, and 55 ± 8% of the SRB communities, respectively. Succession of these SRB at different bioactivity stages based on redox substrates/products (acetate, SO4–2, U(VI), NO3, Fe(II), and Mn(II)) was observed. Desulfovibrio and Desulfococcus dominated SRB communities at 4–31 days, whereas Desulfobacterium became dominant at 80–140 days. By the end of the experiment (day 269), the abundance of these SRB decreased but the overall diversity of groundwater SRB was still higher than non-EVO controls. Up to 62% of the SRB community changes could be explained by groundwater geochemical variables, including those redox substrates/products. A significant (P < 0.001) correlation was observed between groundwater U(VI) concentrations and Desulfovibrio abundance. Finally, our results showed that the members of SRB and their dynamics were correlated significantly with slow EVO biodegradation, electron donor production and maintenance of U(VI)-reducing conditions in the aquifer.

  3. Endocrine-metabolic pathophysiologic conditions and treatment approaches after kidney transplantation.

    Science.gov (United States)

    Gosmanova, Elvira O; Tangpricha, Vin; Gosmanov, Aidar R

    2012-01-01

    To review pathophysiologic conditions and diagnostic and therapeutic approaches in the management of endocrine-metabolic disorders after kidney transplantation (KT). We discuss the assessment of diabetes mellitus (DM), hyperlipidemia, hypertension, and disturbances of bone and mineral metabolism after KT. KT offers patients with end-stage kidney disease substantial improvement in life expectancy and quality of life. Despite amelioration of renal dysfunction, however, these patients are at risk for the deterioration of existing and the development of new endocrine pathologic conditions. Pretransplant DM and new-onset diabetes after transplantation are associated with worse patient and graft survival. Little is known about preventing new-onset diabetes after transplantation and managing DM shortly after KT. In addition to glycemic control in patients with diabetes, management of cardiovascular risk factors includes appropriate recognition and treatment of hypertension and dyslipidemia. After KT, patients are at considerable risk for derangements in calcium and vitamin D metabolism. Immunosuppressive medications may cause compromised glucose and lipid metabolism, which may, in turn, contribute to the progression of preexisting and the development of new posttransplant endocrinopathies. Clinical care of kidney transplant patients should include a comprehensive endocrine assessment before and after KT in close collaboration with transplant nephrology providers. A referral to an endocrinologist should be initiated early during the pretransplant stage, and collaborative management should be maintained in kidney transplant patients to improve clinical outcomes.

  4. Potential of nitrate addition to control the activity of sulfate-reducing prokaryotes in high-temperature oil production systems - a comparative study on a nitrate-treated and an untreated system

    DEFF Research Database (Denmark)

    Gittel, Antje; Sørensen, Ketil; Skovhus, Torben L.

    Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. Adding nitrate to the injection water is applied to control SRP activity by favoring the growth of heterotrophic, nitrate-reducing bacteria (h......NRB) and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). Microbial diversity, abundance of Bacteria, Archaea and sulfate-reducing prokaryotes (SRP) and the potential activity of SRP were studied in production water samples from a nitrate-treated and an untreated system. The reservoirs and the produced water...... share similar physicochemical characteristics. At both sites, Archaea and Archaeoglobus-related SRP dominated the total prokaryotic and the sulfate-reducing community, respectively. It was however indicated from clone libraries and the quantification of 16S rRNA and dsrAB gene copies that Archaeoglobus...

  5. Lactate and acrylate metabolism by Megasphaera elsdenii under batch and steady-state conditions.

    Science.gov (United States)

    Prabhu, Rupal; Altman, Elliot; Eiteman, Mark A

    2012-12-01

    The growth of Megasphaera elsdenii on lactate with acrylate and acrylate analogues was studied under batch and steady-state conditions. Under batch conditions, lactate was converted to acetate and propionate, and acrylate was converted into propionate. Acrylate analogues 2-methyl propenoate and 3-butenoate containing a terminal double bond were similarly converted into their respective saturated acids (isobutyrate and butyrate), while crotonate and lactate analogues 3-hydroxybutyrate and (R)-2-hydroxybutyrate were not metabolized. Under carbon-limited steady-state conditions, lactate was converted to acetate and butyrate with no propionate formed. As the acrylate concentration in the feed was increased, butyrate and hydrogen formation decreased and propionate was increasingly generated, while the calculated ATP yield was unchanged. M. elsdenii metabolism differs substantially under batch and steady-state conditions. The results support the conclusion that propionate is not formed during lactate-limited steady-state growth because of the absence of this substrate to drive the formation of lactyl coenzyme A (CoA) via propionyl-CoA transferase. Acrylate and acrylate analogues are reduced under both batch and steady-state growth conditions after first being converted to thioesters via propionyl-CoA transferase. Our findings demonstrate the central role that CoA transferase activity plays in the utilization of acids by M. elsdenii and allows us to propose a modified acrylate pathway for M. elsdenii.

  6. Metabolic Characteristics of a Glucose-Utilizing Shewanella oneidensis Strain Grown under Electrode-Respiring Conditions.

    Directory of Open Access Journals (Sweden)

    Gen Nakagawa

    Full Text Available In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode, the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.

  7. Elucidating microbial processes in nitrate- and sulfate-reducing systems using sulfur and oxygen isotope ratios: The example of oil reservoir souring control

    Science.gov (United States)

    Hubert, Casey; Voordouw, Gerrit; Mayer, Bernhard

    2009-07-01

    Sulfate-reducing bacteria (SRB) are ubiquitous in anoxic environments where they couple the oxidation of organic compounds to the production of hydrogen sulfide. This can be problematic for various industries including oil production where reservoir "souring" (the generation of H 2S) requires corrective actions. Nitrate or nitrite injection into sour oil fields can promote SRB control by stimulating organotrophic nitrate- or nitrite-reducing bacteria (O-NRB) that out-compete SRB for electron donors (biocompetitive exclusion), and/or by lithotrophic nitrate- or nitrite-reducing sulfide oxidizing bacteria (NR-SOB) that remove H 2S directly. Sulfur and oxygen isotope ratios of sulfide and sulfate were monitored in batch cultures and sulfidic bioreactors to evaluate mitigation of SRB activities by nitrate or nitrite injection. Sulfate reduction in batch cultures of Desulfovibrio sp. strain Lac15 indicated typical Rayleigh-type fractionation of sulfur isotopes during bacterial sulfate reduction (BSR) with lactate, whereas oxygen isotope ratios in unreacted sulfate remained constant. Sulfur isotope fractionation in batch cultures of the NR-SOB Thiomicrospira sp. strain CVO was minimal during the oxidation of sulfide to sulfate, which had δ18O SO4 values similar to that of the water-oxygen. Treating an up-flow bioreactor with increasing doses of nitrate to eliminate sulfide resulted in changes in sulfur isotope ratios of sulfate and sulfide but very little variation in oxygen isotope ratios of sulfate. These observations were similar to results obtained from SRB-only, but different from those of NR-SOB-only pure culture control experiments. This suggests that biocompetitive exclusion of SRB took place in the nitrate-injected bioreactor. In two replicate bioreactors treated with nitrite, less pronounced sulfur isotope fractionation and a slight decrease in δ18O SO4 were observed. This indicated that NR-SOB played a minor role during dosing with low nitrite and that

  8. Acute toxicity of heavy metals to acetate-utilizing mixed cultures of sulfate-reducing bacteria: EC100 and EC50.

    Science.gov (United States)

    Utgikar, V P; Chen, B Y; Chaudhary, N; Tabak, H H; Haines, J R; Govind, R

    2001-12-01

    Acid mine drainage from abandoned mines and acid mine pit lakes is an important environmental concern and usually contains appreciable concentrations of heavy metals. Because sulfate-reducing bacteria (SRB) are involved in the treatment of acid mine drainage, knowledge of acute metal toxicity levels for SRB is essential for the proper functioning of the treatment system for acid mine drainage. Quantification of heavy metal toxicity to mixed cultures of SRB is complicated by the confounding effects of metal hydroxide and sulfide precipitation, biosorption, and complexation with the constituents of the reaction matrix. The objective of this paper was to demonstrate that measurements of dissolved metal concentrations could be used to determine the toxicity parameters for mixed cultures of sulfate-reducing bacteria. The effective concentration, 100% (EC100), the lowest initial dissolved metal concentrations at which no sulfate reduction is observed, and the effective concentration, 50% (EC50), the initial dissolved metal concentrations resulting in a 50% decrease in sulfate reduction, for copper and zinc were determined in the present study by means of nondestructive, rapid physical and chemical analytical techniques. The reaction medium used in the experiments was designed specifically (in terms of pH and chemical composition) to provide the nutrients necessary for the sulfidogenic activity of the SRB and to preclude chemical precipitation of the metals under investigation. The toxicity-mitigating effects of biosorption of dissolved metals were also quantified. Anaerobic Hungate tubes were set up (at least in triplicate) and monitored for sulfate-reduction activity. The onset of SRB activity was detected by the blackening of the reaction mixture because of formation of insoluble ferrous sulfide. The EC100 values were found to be 12 mg/L for copper and 20 mg/L for zinc. The dissolved metal concentration measurements were effective as the indicators of the effect of the

  9. Respiratory metabolism of illuminated leaves depends on CO2 and O2 conditions.

    Science.gov (United States)

    Tcherkez, Guillaume; Bligny, Richard; Gout, Elizabeth; Mahé, Aline; Hodges, Michael; Cornic, Gabriel

    2008-01-15

    Day respiration is the process by which nonphotorespiratory CO2 is produced by illuminated leaves. The biological function of day respiratory metabolism is a major conundrum of plant photosynthesis research: because the rate of CO2 evolution is partly inhibited in the light, it is viewed as either detrimental to plant carbon balance or necessary for photosynthesis operation (e.g., in providing cytoplasmic ATP for sucrose synthesis). Systematic variations in the rate of day respiration under contrasting environmental conditions have been used to elucidate the metabolic rationale of respiration in the light. Using isotopic techniques, we show that both glycolysis and the tricarboxylic acid cycle activities are inversely related to the ambient CO2/O2 ratio: day respiratory metabolism is enhanced under high photorespiratory (low CO2) conditions. Such a relationship also correlates with the dihydroxyacetone phosphate/Glc-6-P ratio, suggesting that photosynthetic products exert a control on day respiration. Thus, day respiration is normally inhibited by phosphoryl (ATP/ADP) and reductive (NADH/NAD) poise but is up-regulated by photorespiration. Such an effect may be related to the need for NH2 transfers during the recovery of photorespiratory cycle intermediates.

  10. Metabolic profile of santa inês ewes whith low body condition score during peripartum

    Directory of Open Access Journals (Sweden)

    Nayara Resende Nasciutti

    2012-02-01

    Full Text Available The objective of this study was to analyse the variations in the metabolic profile of protein, energy enzyme and mineral of Santa Inês ewes with low body condition score (BCS during peripartum. Blood samples were collected from 12 animals by jugular venipuncture to determine the serum biochemical profiles of protein, energy, mineral and enzyme metabolisms. Samples were collected on the following days: days 28, 21, 14, and 7 before lambing, at birth and, at days 2, 4, 7, 14, 21, and 28 postpartum (dpp. The samples were centrifuged and the serum analysed by Automated-Analyser. There was no alteration of the BCS during the 28 dpp, between 0.6 and 2.1 ± 2.4 ± 0.5, and was considered, as lean. The values of the total serum protein, globulin, albumin, and albumin/globulin ratio were reduced effective from the period before birth until 28dpp. The values of beta-hydroxybutyrate, calcium, phosphorus and magnesium remained below those of reference values. The concentrations of alanin aminotransferase (ALT were decreased particularly during the weeks before delivery. It was concluded that Santa Inês sheep with low body condition score demonstrated a reduction in the metabolism of proteins, energy, mineral and enzyme during peripartum.

  11. Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65; Estudio comparativo de la corrosion inducida por microorganismos sulfatorreductores, en un acero inoxidable 304L sensibilizado y un acero al carbono API X65

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Gonzalez F, E.; Arganis J, C.; Luna C, P.; Carapia M, L. [ININ, Carretera Mexico-Toluca Km. 36.5, 52045 Estado de Mexico (Mexico)]. e-mail: ads@nuclear.inin.mx

    2004-07-01

    In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

  12. Regulatory network rewiring for secondary metabolism in Arabidopsis thaliana under various conditions

    Science.gov (United States)

    2014-01-01

    Background Plant secondary metabolites are critical to various biological processes. However, the regulations of these metabolites are complex because of regulatory rewiring or crosstalk. To unveil how regulatory behaviors on secondary metabolism reshape biological processes, we constructed and analyzed a dynamic regulatory network of secondary metabolic pathways in Arabidopsis. Results The dynamic regulatory network was constructed through integrating co-expressed gene pairs and regulatory interactions. Regulatory interactions were either predicted by conserved transcription factor binding sites (TFBSs) or proved by experiments. We found that integrating two data (co-expression and predicted regulatory interactions) enhanced the number of highly confident regulatory interactions by over 10% compared with using single data. The dynamic changes of regulatory network systematically manifested regulatory rewiring to explain the mechanism of regulation, such as in terpenoids metabolism, the regulatory crosstalk of RAV1 (AT1G13260) and ATHB1 (AT3G01470) on HMG1 (hydroxymethylglutaryl-CoA reductase, AT1G76490); and regulation of RAV1 on epoxysqualene biosynthesis and sterol biosynthesis. Besides, we investigated regulatory rewiring with expression, network topology and upstream signaling pathways. Regulatory rewiring was revealed by the variability of genes’ expression: pathway genes and transcription factors (TFs) were significantly differentially expressed under different conditions (such as terpenoids biosynthetic genes in tissue experiments and E2F/DP family members in genotype experiments). Both network topology and signaling pathways supported regulatory rewiring. For example, we discovered correlation among the numbers of pathway genes, TFs and network topology: one-gene pathways (such as δ-carotene biosynthesis) were regulated by a fewer TFs, and were not critical to metabolic network because of their low degrees in topology. Upstream signaling pathways of 50

  13. Rogoznica Lake - a Conceptual Framework to Study Sulfate-reducing Bacteria Across a Wide Range of Anoxic/hypoxic Marine Environments

    Science.gov (United States)

    Cankovic, M.; Collins, G.; Petrić, I.; Ciglenečki, I.

    2016-02-01

    Today's oceans and seas are experiencing, among other changes, oxygen depletion, resulting in hypoxia/anoxia. Consequently, toxic H2S,generated by sulfate-reducing bacteria (SRB), is released. The prevalence of this type of environment has increased rapidly over the past decades, especially in costal zones. Rogoznica Lake (Croatia) is a typical, extreme euxinic, seawater system, with a permanently anoxic bottom water layer. As such, it represents a natural laboratory to study SRB. The objective of this study was to characterize the SRB community inhabiting the hypoxic/anoxic water column and sediment of Rogoznica Lake. The distribution, diversity, activity and abundance of SRB were investigated using different molecular techniques accompanied by physico-chemical and organic matter measurements. Results indicated seasonal variations in SRB diversity, abundance and activity, as well as variations between different samples. A complex and diverse distribution of SRB was revealed, supporting the idea that habitat-specific SRB communities are the main drivers of anaerobic degradation of organic matter, as well as cycling of sulfur and carbon species, in the Lake. Furthermore, low sequence homology to cultured SRB indicated presence of a specific SRB community in the Lake.While eutrophication is a leading cause of impairment of many freshwater and coastal marine ecosystems in the world, hypoxia and anoxia continue to threaten tourism and fisheries worldwide. In such circumstances better understanding of SRB spatio-temporal distribution and dynamics would be of ecological and economical importance.

  14. The patterns of bacterial community and relationships between sulfate-reducing bacteria and hydrochemistry in sulfate-polluted groundwater of Baogang rare earth tailings.

    Science.gov (United States)

    An, Xinli; Baker, Paul; Li, Hu; Su, Jianqiang; Yu, Changping; Cai, Chao

    2016-11-01

    Microorganisms are the primary agents responsible for the modification, degradation, and/or detoxification of pollutants, and thus, they play a major role in their natural attenuation; yet, little is known about the structure and diversity of the subsurface community and relationships between microbial community and groundwater hydrochemistry. In this study, denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) allowed a comparative microbial community analysis of sulfate-contaminated groundwater samples from nine different wells in the region of Baogang rare earth tailings. Using real-time PCR, the abundance of total bacteria and the sulfate-reducing genes of aprA and dsrB were quantified. Statistical analyses showed a clear distinction of the microbial community diversity between the contaminated and uncontaminated samples, with Proteobacteria being the most dominant members of the microbial community. SO4(2-) concentrations exerted a significant effect on the variation of the bacterial community (P groundwater. The uncontaminated groundwater with low sulfate concentration harbored higher abundance of SRB than that in the polluted samples, while no significant correlation was observed between sulfate concentrations and SRB abundances in this study, suggesting other environmental factors possibly contributed to different distributions and abundances of SRB in the different sites. The results should facilitate expanded studies to identify robust microbe-environment interactions and provide a strong foundation for qualitative exploration of the bacterial diversity in rare earth tailings groundwater that might ultimately be incorporated into the remediation of environmental contamination.

  15. The sulfate-rich and extreme saline sediment of the ephemeral tirez lagoon: a biotope for acetoclastic sulfate-reducing bacteria and hydrogenotrophic methanogenic archaea.

    Science.gov (United States)

    Montoya, Lilia; Lozada-Chávez, Irma; Amils, Ricardo; Rodriguez, Nuria; Marín, Irma

    2011-01-01

    Our goal was to examine the composition of methanogenic archaea (MA) and sulfate-reducing (SRP) and sulfur-oxidizing (SOP) prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain). Thus, adenosine-5'-phosphosulfate (APS) reductase α (aprA) and methyl coenzyme M reductase α (mcrA) gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and dry seasons from the anoxic sediment were compared qualitatively via denaturing gradient gel electrophoresis (DGGE) fingerprint analysis. Phylogenetic analyses allowed the detection of SRP belonging to Desulfobacteraceae, Desulfohalobiaceae, and Peptococcaceae in ∂-proteobacteria and Firmicutes and SOP belonging to Chromatiales/Thiotrichales clade and Ectothiorhodospiraceae in γ-proteobacteria as well as MA belonging to methylotrophic species in Methanosarcinaceae and one hydrogenotrophic species in Methanomicrobiaceae. We also estimated amino acid composition, GC content, and preferential codon usage for the AprA and McrA sequences from halophiles, nonhalophiles, and Tirez phylotypes. Even though our results cannot be currently conclusive regarding the halotolerant strategies carried out by Tirez phylotypes, we discuss the possibility of a plausible "salt-in" signal in SRP and SOP as well as of a speculative complementary haloadaptation between salt-in and salt-out strategies in MA.

  16. The Sulfate-Rich and Extreme Saline Sediment of the Ephemeral Tirez Lagoon: A Biotope for Acetoclastic Sulfate-Reducing Bacteria and Hydrogenotrophic Methanogenic Archaea

    Directory of Open Access Journals (Sweden)

    Lilia Montoya

    2011-01-01

    Full Text Available Our goal was to examine the composition of methanogenic archaea (MA and sulfate-reducing (SRP and sulfur-oxidizing (SOP prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain. Thus, adenosine-5′-phosphosulfate (APS reductase α (aprA and methyl coenzyme M reductase α (mcrA gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and dry seasons from the anoxic sediment were compared qualitatively via denaturing gradient gel electrophoresis (DGGE fingerprint analysis. Phylogenetic analyses allowed the detection of SRP belonging to Desulfobacteraceae, Desulfohalobiaceae, and Peptococcaceae in ∂-proteobacteria and Firmicutes and SOP belonging to Chromatiales/Thiotrichales clade and Ectothiorhodospiraceae in γ-proteobacteria as well as MA belonging to methylotrophic species in Methanosarcinaceae and one hydrogenotrophic species in Methanomicrobiaceae. We also estimated amino acid composition, GC content, and preferential codon usage for the AprA and McrA sequences from halophiles, nonhalophiles, and Tirez phylotypes. Even though our results cannot be currently conclusive regarding the halotolerant strategies carried out by Tirez phylotypes, we discuss the possibility of a plausible “salt-in” signal in SRP and SOP as well as of a speculative complementary haloadaptation between salt-in and salt-out strategies in MA.

  17. Bioassessment of heavy metal toxicity and enhancement of heavy metal removal by sulfate-reducing bacteria in the presence of zero valent iron.

    Science.gov (United States)

    Guo, Jing; Kang, Yong; Feng, Ying

    2017-12-01

    A simple and valid toxicity evaluation of Zn2+, Mn2+ and Cr6+ on sulfate-reducing bacteria (SRB) and heavy metal removal were investigated using the SRB system and SRB+Fe0 system. The heavy metal toxicity coefficient (β) and the heavy metal concentration resulting in 50% inhibition of sulfate reduction (I) from a modeling process were proposed to evaluate the heavy metal toxicity and nonlinear regression was applied to search for evaluation indices β and I. The heavy metal toxicity order was Cr6+ > Mn2+ > Zn2+. Compared with the SRB system, the SRB+Fe0 system exhibited a better capability for sulfate reduction and heavy metal removal. The heavy metal removal was above 99% in the SRB+Fe0 system, except for Mn2+. The energy-dispersive spectroscopy (EDS) analysis showed that the precipitates were removed primarily as sulfide for Zn2+ and hydroxide for Mn2+ and Cr6+.The method of evaluating the heavy metal toxicity on SRB was of great significance to understand the fundamentals of the heavy metal toxicity and inhibition effects on the microorganism and regulate the process of microbial sulfate reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Development and comparison of SYBR Green quantitative real-time PCR assays for detection and enumeration of sulfate-reducing bacteria in stored swine manure.

    Science.gov (United States)

    Spence, C; Whitehead, T R; Cotta, M A

    2008-12-01

    To develop and evaluate primer sets targeted to the dissimilatory sulfite reductase gene (dsrA) for use in quantitative real-time PCR detection of sulfate-reducing bacteria (SRB) in stored swine manure. Degenerate primer sets were developed to detect SRB in stored swine manure. These were compared with a previously reported primer set, DSR1F+ and DSR-R, for their coverage and ability to detect SRB communities in stored swine manure. Sequenced clones were most similar to Desulfovibrio sp. and Desulfobulbus sp., and these SRB populations differed within different manure ecosystems. Sulfur content of swine diets was shown to affect the population of Desulfobulbus-like Group 1 SRB in manure. The newly developed assays were able to enumerate and discern different groups of SRB, and suggest a richly diverse and as yet undescribed population of SRB in swine manure. The PCR assays described here provide improved and efficient molecular tools for quantitative detection of SRB populations. This is the first study to show population shifts of SRB in swine manure, which are a result of either the effects of swine diets or the maturity of the manure ecosystem.

  19. Culturable diversity of lithotrophic haloalkaliphilic sulfate-reducing bacteria in soda lakes and the description of Desulfonatronum thioautotrophicum sp. nov., Desulfonatronum thiosulfatophilum sp. nov., Desulfonatronovibrio thiodismutans sp. nov., and Desulfonatronovibrio magnus sp. nov.

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Kolganova, T.V.; Detkova, E.N.; Galinski, E.A.; Muyzer, G.

    2011-01-01

    Soda lake sediments usually contain high concentrations of sulfide indicating active sulfate reduction. Monitoring of sulfate-reducing bacteria (SRB) in soda lakes demonstrated a dominance of two groups of culturable SRB belonging to the order Desulfovibrionales specialized in utilization of

  20. Psychrophilic sulfate-reducing bacteria isolated from permanently cold Arctic marine sediments: description of Desulfofrigrus oceanense gen. nov., sp nov., Desulfofrigus fragile sp nov., Desulfofaba gelida gen. nov., sp nov., Desulfotalea psychrophila gen. nov., sp nov and Desulfotalea arctica sp

    DEFF Research Database (Denmark)

    Knoblauch, C.; Sahm, K.; Jørgensen, BB

    1999-01-01

    known sulfate reducers. Due to the phylogenetic and phenotypic differences between the new isolates and their closest relatives, establishment of the new genera Desulfotalea gen. nov., Desulfofaba gen. nov. and Desulfofrigus gen. nov. is proposed, with strain ASv26(T) as the type strain of the type...

  1. Desulfovibrio oceani subsp. oceani sp. nov., subsp. nov and Desulfovibrio oceani subsp. galateae subsp. nov., novel sulfate-reducing bacteria isolated from the oxygen minimum zone off the coast of Peru

    DEFF Research Database (Denmark)

    Finster, Kai; Kjeldsen, Kasper Urup

    2010-01-01

    Two deltaproteobacterial sulfate reducers, designated strain I.8.1T and I.9.1T, were isolated from the oxygen minimum zone water column off the coast of Peru at 400 and 500 m water depth. The strains were Gram-negative, vibrio-shaped and motile. Both strains were psychrotolerant, grew optimally...

  2. Modulation of phenolic metabolism under stress conditions in a Lotus japonicus mutant lacking plastidic glutamine synthetase

    Directory of Open Access Journals (Sweden)

    Margarita eGarcía-Calderón

    2015-09-01

    Full Text Available This paper was aimed to investigate the possible implications of the lack of plastidic glutamine synthetase (GS2 in phenolic metabolism during stress responses in the model legume Lotus japonicus. Important changes in the transcriptome were detected in a GS2 mutant called Ljgln2-2, compared to the wild type, in response to two separate stress conditions, such as drought or the result of the impairment of the photorespiratory cycle. Detailed transcriptomic analysis showed that the biosynthesis of phenolic compounds was affected in the mutant plants in these two different types of stress situations. For this reason, the genes and metabolites related to this metabolic route were further investigated using a combined approach of gene expression analysis and metabolite profiling. A high induction of the expression of several genes for the biosynthesis of different branches of the phenolic biosynthetic pathway was detected by qRT-PCR. The extent of induction was always higher in Ljgln2-2, probably reflecting the higher stress levels present in this genotype. This was paralleled by accumulation of several kaempferol and quercetine glycosides, some of them described for the first time in L. japonicus, and of high levels of the isoflavonoid vestitol. The results obtained indicate that the absence of GS2 affects different aspects of phenolic metabolism in L .japonicus plants in response to stress.

  3. Temperature dependent growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi.

    Science.gov (United States)

    Fitzgibbon, Quinn P; Simon, Cedric J; Smith, Gregory G; Carter, Chris G; Battaglene, Stephen C

    2017-05-01

    We examined the effects of temperature on the growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi, in order to determine if temperature acclimated aerobic scope correlates with optimum for growth and to establish the thermal tolerance window for this emerging aquaculture species. Juvenile lobsters (initial weight=10.95±0.47g) were reared (n=7) at temperatures from 11.0 to 28.5°C for 145days. All lobsters survived from 14.5 to 25.0°C while survival was reduced at 11.0°C (86%) and all lobsters died at 28.5°C. Lobster specific growth rate and specific feed consumption displayed a unimodal response with temperature, peaking at 21.5°C. Lobster standard, routine and maximum metabolic rates, and aerobic scope all increased exponentially up to maximum non-lethal temperature. Optimum temperature for growth did not correspond to that for maximum aerobic scope suggesting that aerobic scope is not an effective predictor of the thermal optimum of spiny lobsters. Plateauing of specific feed consumption beyond 21.5°C suggests that temperature dependent growth of lobsters is limited by capacity to ingest or digest sufficient food to meet increasing maintenance metabolic demands at high temperatures. The nutritional condition of lobsters was not influenced by temperature and feed conversion ratio was improved at lower temperatures. These findings add to a growing body of evidence questioning the generality of aerobic scope to describe the physiological thermal boundaries of aquatic ectotherms and suggest that feed intake plays a crucial role in regulating performance at thermal extremes. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Uterine metabolism of the pregnant rabbit under chronic steady-state conditions

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.L.; Gilbert, M.; Block, S.M.; Battaglia, F.C.

    1986-05-01

    The study of uterine metabolism in pregnancy under chronic steady-state conditions has been confined to large mammals and, more recently, to the guinea pig. The pregnant rabbit is of interest because of its short gestation and large litter size. We developed an indirect approach involving retrograde catheterization of the uterine venous drainage, permitting measurement of both uterine metabolic quotients and uterine uptakes. Radioactive microspheres were used to measure blood flow. A large lactate and ammonia efflux from the uterus was found. In the fed state, ketogenic substrates were taken up in small amounts. However, during starvation a significant increase in ketoacid uptake was observed with a concurrent fall in acetate uptake. There was a large glucose/oxygen quotient across the uterus, but the glucose plus lactate/oxygen quotient was comparable to that found in the sheep and guinea pig (0.6 +/- 0.1). It is apparent that in all three species studied under chronic steady-state conditions (sheep, guinea pig, and rabbit) there is a large glucose uptake associated with a net lactate production, and fuels other than glucose and lactate must be used by the uterus.

  5. Microbial Diversity and Community Structure of Sulfate-Reducing and Sulfur-Oxidizing Bacteria in Sediment Cores from the East China Sea

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2017-11-01

    Full Text Available Sulfate-reducing bacteria (SRB and sulfur-oxidizing bacteria (SOB have been studied extensively in marine sediments because of their vital roles in both sulfur and carbon cycles, but the available information regarding the highly diverse SRB and SOB communities is not comprehensive. High-throughput sequencing of functional gene amplicons provides tremendous insight into the structure and functional potential of complex microbial communities. Here, we explored the community structure, diversity, and abundance of SRB and SOB simultaneously through 16S rRNA, dsrB and soxB gene high-throughput sequencing and quantitative PCR analyses of core samples from the East China Sea. Overall, high-throughput sequencing of the dsrB and soxB genes achieved almost complete coverage (>99% and revealed the high diversity, richness, and operational taxonomic unit (OTU numbers of the SRB and SOB communities, which suggest the existence of an active sulfur cycle in the study area. Further analysis demonstrated that rare species make vital contributions to the high richness, diversity, and OTU numbers obtained. Depth-based distributions of the dsrB, soxB, and 16S rRNA gene abundances indicated that the SRB abundance might be more sensitive to the sedimentary dynamic environment than those of total bacteria and SOB. In addition, the results of unweighted pair group method with arithmetic mean (UPGMA clustering analysis and redundancy analysis revealed that environmental parameters, such as depth and dissolved inorganic nitrogen concentrations, and the sedimentary dynamic environment, which differed between the two sampling stations, can significantly influence the community structures of total bacteria, SRB, and SOB. This study provided further comprehensive information regarding the characteristics of SRB and SOB communities.

  6. Alkane biodegradation and dynamics of phylogenetic subgroups of sulfate-reducing bacteria in an anoxic coastal marine sediment artificially contaminated with oil.

    Science.gov (United States)

    Miralles, Gilles; Grossi, Vincent; Acquaviva, Monique; Duran, Robert; Claude Bertrand, Jean; Cuny, Philippe

    2007-07-01

    For 503 days, unoiled control and artificially oiled sediments were incubated in situ at 20m water depth in a Mediterranean coastal area. Degradation of the aliphatic fraction of the oil added was followed by GC-MS. At the same time, terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA encoding genes was used to detect dynamics in the sulfate-reducing bacteria (SRB) community in response to the oil contamination. Specific polymerase chain reaction (PCR) primer sets for five generic or suprageneric groups of SRB were used for PCR amplification of DNA extracted from sediments. During the experiment, hydrocarbons from C(17) to C(30) were significantly degraded even in strictly anoxic sediment layers. Of the five SRB groups, only two groups were detected in the sediments (control and oiled), namely the Desulfococcus-Desulfonema-Desulfosarcina-like group and the Desulfovibrio-Desulfomicrobium-like group. Statistical analysis of community patterns revealed dynamic changes over time within these two groups following the contamination. Significant differences in community patterns were recorded in artificially oiled compared with control sediments. Cloning and sequencing of 16S rRNA encoding genes performed after 503 days showed that many of the most abundant sequences were closely related to hydrocarbonoclastic SRB which could have played an active role in the observed biodegradation of aliphatic hydrocarbons. Results from the present study provide useful information on the dynamics of dominant SRB in heavily oil-contaminated sediments and their potential for anaerobic biodegradation for the treatment of spilled oil in anoxic marine environments.

  7. Effect of dietary inorganic sulfur level on growth performance, fecal composition, and measures of inflammation and sulfate-reducing bacteria in the intestine of growing pigs.

    Science.gov (United States)

    Kerr, B J; Weber, T E; Ziemer, C J; Spence, C; Cotta, M A; Whitehead, T R

    2011-02-01

    Two experiments investigated the impact of dietary inorganic S on growth performance, intestinal inflammation, fecal composition, and the presence of sulfate-reducing bacteria (SRB). In Exp. 1, individually housed pigs (n = 42; 13.8 kg) were fed diets containing 2,300 or 2,100 mg/kg of S for 24 d. Decreasing dietary S had no effect on ADG, ADFI, or G:F. In Exp. 2, pigs (n = 64; 13.3 kg) were fed diets containing 0, 0.625, 1.25, 2.5, or 5.0% CaSO(4), thereby increasing dietary S from 2,900 to 12,100 mg/kg. Two additional diets were fed to confirm the lack of an impact due to feeding low dietary S on pig performance and to determine if the increased Ca and P content in the diets containing CaSO(4) had an impact on growth performance. Pigs were fed for 35 d. Ileal tissue, ileal mucosa, and colon tissue were harvested from pigs fed the 0 and 5% CaSO(4) diets (low-S and high-S, respectively) to determine the impact of dietary S on inflammation-related mRNA, activity of mucosal alkaline phosphatase and sucrase, and pathways of inflammatory activation. Real-time PCR was used to quantify SRB in ileal and colon digesta samples and feces. Fecal pH, sulfide, and ammonia concentrations were also determined. There was no impact on growth performance in pigs fed the diet reduced in dietary S or by the increase of dietary Ca and P. Increasing dietary S from 2,900 to 12,100 mg/kg had a linear (P bacteria in ileal digesta, but increased (P growing pigs can tolerate relatively high amounts of dietary inorganic S, but high dietary S content alters inflammatory mediators and intestinal bacteria.

  8. Isolation and characterization of Desulfocurvus thunnarius sp. nov., a sulfate-reducing bacterium isolated from an anaerobic sequencing batch reactor treating cooking wastewater.

    Science.gov (United States)

    Hamdi, Olfa; Ben Hania, Wajdi; Postec, Anne; Bartoli, Manon; Hamdi, Moktar; Bouallagui, Hassib; Fauque, Guy; Ollivier, Bernard; Fardeau, Marie-Laure

    2013-11-01

    A novel anaerobic, chemo-organotrophic, sulfate-reducing bacterium, designated strain Olac 40(T), was isolated from a Tunisian wastewater digestor. Cells were curved, motile rods or vibrios (5.0-7.0×0.5 µm). Strain Olac 40(T) grew at temperatures between 15 and 50 °C (optimum 40 °C), and between pH 5.0 and 9.0 (optimum pH 7.1). It did not require NaCl for growth but tolerated it up to 50 g l(-1) (optimum 2 g l(-1)). In the presence of sulfate or thiosulfate, strain Olac 40(T) used lactate, pyruvate and formate as energy sources. Growth was observed on H2 only in the presence of acetate as carbon source. In the presence of sulfate or thiosulfate, the end products of lactate oxidation were acetate, sulfide and CO2. Sulfate, thiosulfate and sulfite were used as terminal electron acceptors, but not elemental sulfur, nitrate or nitrite. The genomic DNA G+C content of strain Olac 40(T) was 70 mol%. The profile of polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, aminophospholipid and four phospholipids. The main fatty acids were C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Olac 40(T) was affiliated with the family Desulfovibrionaceae within the class Deltaproteobacteria. On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain Olac 40(T) is proposed to be assigned to a novel species of the genus Desulfocurvus, for which the name Desulfocurvus thunnarius is proposed. The type strain is Olac 40(T) ( = DSM 26129(T) = JCM 18546(T)).

  9. Desulfobulbus oligotrophicus sp. nov., a sulfate-reducing and propionate-oxidizing bacterium isolated from a municipal anaerobic sewage sludge digester.

    Science.gov (United States)

    El Houari, Abdelaziz; Ranchou-Peyruse, Magali; Ranchou-Peyruse, Anthony; Dakdaki, Adrien; Guignard, Marion; Idouhammou, Lahcen; Bennisse, Rhizlane; Bouterfass, Radia; Guyoneaud, Rémy; Qatibi, Abdel-Illah

    2017-02-01

    A novel, mesophilic, strictly anaerobic, sulfate-reducing and propionate-oxidizing bacterium, strain Prop6T, was enriched and isolated from a municipal anaerobic sewage sludge digester. Cells were Gram-stain-negative, catalase-positive, oval rods, motile by means of amphitrichous flagella, non-spore-forming and contained menaquinone MK-5(H2) as the major respiratory quinone. The genomic DNA G+C content was 51.7 mol%. The optimal NaCl concentration, temperature and pH were 2-5 g l-1, 35 °C and pH 7.6, respectively. Strain Prop6T could only oxidize propionate, lactate and pyruvate (weakly) with sulfate, sulfite or thiosulfate, mainly to acetate. Strain Prop6T fermented pyruvate and lactate to acetate and propionate. The predominant cellular fatty acids were C14 : 0, C16 : 0, C16 : 1ω7, C16 : 1ω5, C17 : 1ω6 and C18 : 1ω7. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the newly isolated strain was a member of the genus Desulfobulbus, with Desulfobulbus elongatus DSM 2908T, Desulfobulbus propionicus DSM 2032T and Desulfobulbus rhabdoformis DSM 8777T as closest relatives among species with validly published names. On the basis of genotypic, phenotypic and chemotaxonomic characteristics, it is proposed that the isolate represents a novel species, Desulfobulbus oligotrophicus sp. nov. The type strain is Prop6T (=DSM 103420T=JCM 31535T).

  10. Distribution of iron- and sulfate-reducing bacteria across a coastal acid sulfate soil (CASS environment: implications for passive bioremediation by tidal inundation

    Directory of Open Access Journals (Sweden)

    Yu-Chen eLing

    2015-07-01

    Full Text Available Coastal acid sulfate soils (CASS constitute a serious and global environmental problem. Oxidation of iron sulfide minerals exposed to air generates sulfuric acid with consequently negative impacts on coastal and estuarine ecosystems. Tidal inundation represents one current treatment strategy for CASS, with the aim of neutralizing acidity by triggering microbial iron- and sulfate-reduction and inducing the precipitation of iron-sulfides. Although well-known functional guilds of bacteria drive these processes, their distributions within CASS environments, as well as their relationships to tidal cycling and the availability of nutrients and electron acceptors, are poorly understood. These factors will determine the long-term efficacy of passive CASS remediation strategies. Here we studied microbial community structure and functional guild distribution in sediment cores obtained from ten depths ranging from 0-20 cm in three sites located in the supra-, inter- and sub-tidal segments, respectively, of a CASS-affected salt marsh (East Trinity, Cairns, Australia. Whole community 16S rRNA gene diversity within each site was assessed by 454 pyrotag sequencing and bioinformatic analyses in the context of local hydrological, geochemical and lithological factors. The results illustrate spatial overlap, or close association, of iron- and sulfate-reducing bacteria in an environment rich in organic matter and controlled by parameters such as acidity, redox potential, degree of water saturation, and mineralization. The observed spatial distribution implies the need for empirical understanding of the timing, relative to tidal cycling, of various terminal electron-accepting processes that control acid generation and biogeochemical iron and sulfur cycling.

  11. Bacterial communities in haloalkaliphilic sulfate-reducing bioreactors under different electron donors revealed by 16S rRNA MiSeq sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jiemin [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Xuemei; Li, Yuguang [101 Institute, Ministry of Civil Affairs, Beijing 100070 (China); Xing, Jianmin, E-mail: jmxing@ipe.ac.cn [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China)

    2015-09-15

    Highlights: • Bacterial communities of haloalkaliphilic bioreactors were investigated. • MiSeq was first used in analysis of communities of haloalkaliphilic bioreactors. • Electron donors had significant effect on bacterial communities. - Abstract: Biological technology used to treat flue gas is useful to replace conventional treatment, but there is sulfide inhibition. However, no sulfide toxicity effect was observed in haloalkaliphilic bioreactors. The performance of the ethanol-fed bioreactor was better than that of lactate-, glucose-, and formate-fed bioreactor, respectively. To support this result strongly, Illumina MiSeq paired-end sequencing of 16S rRNA gene was applied to investigate the bacterial communities. A total of 389,971 effective sequences were obtained and all of them were assigned to 10,220 operational taxonomic units (OTUs) at a 97% similarity. Bacterial communities in the glucose-fed bioreactor showed the greatest richness and evenness. The highest relative abundance of sulfate-reducing bacteria (SRB) was found in the ethanol-fed bioreactor, which can explain why the performance of the ethanol-fed bioreactor was the best. Different types of SRB, sulfur-oxidizing bacteria, and sulfur-reducing bacteria were detected, indicating that sulfur may be cycled among these microorganisms. Because high-throughput 16S rRNA gene paired-end sequencing has improved resolution of bacterial community analysis, many rare microorganisms were detected, such as Halanaerobium, Halothiobacillus, Desulfonatronum, Syntrophobacter, and Fusibacter. 16S rRNA gene sequencing of these bacteria would provide more functional and phylogenetic information about the bacterial communities.

  12. Effect of specific gas loading rate on thermophilic (55 degrees C) acidifying (pH 6) and sulfate reducing granular sludge reactors.

    Science.gov (United States)

    Lens, P N L; Klijn, R; van Lier, J B; Lettinga, G

    2003-03-01

    The effect of the specific gas loading rate on the acidifying, sulfate reducing and sulfur removal capacity of thermophilic (55 degrees C; pH 6.0) granular sludge bed reactors treating partly acidified wastewater was investigated. A comparison was made between a regular UASB reactor and a UASB reactor continuously sparged with N(2) at a specific gas loading rate of 30 m(3)m(-2)d(-1). Both UASB reactors (upflow velocity 1.0 mh(-1), hydraulic retention time about 5h) were fed a synthetic wastewater containing starch, sucrose, lactate, propionate and acetate and a low sulfate concentration (COD/SO(4)(2-) ratio of 10) at volumetric organic loading rates (OLR) ranging from 4.0 to 49.8 gCODl(-1) reactord(-1). Immediately after imposing an OLR of 25 gCODl(-1) reactord(-1), the acidification and sulfate reduction efficiency dropped to 80% and 30%, respectively, in the UASB reactor. Both efficiencies recovered slowly to 100% during the course of the experiment. In the N(2) sparged reactor, both the acidification and sulfate reduction efficiency remained 100% following the OLR increase to 25 gCODl(-1) reactord(-1). However, the sulfate reduction efficiency gradually decreased to about 20% at the end of the experiment. The biogas (CO(2) and CH(4)) production rate in the UASB was very low, i.e. UASB reactor effluent was always below 25 mgl(-1), but incomplete sulfate reduction kept the maximal H(2)S stripping efficiency below 70%.

  13. Distribution of iron- and sulfate-reducing bacteria across a coastal acid sulfate soil (CASS) environment: implications for passive bioremediation by tidal inundation

    Science.gov (United States)

    Ling, Yu-Chen; Bush, Richard; Grice, Kliti; Tulipani, Svenja; Berwick, Lyndon; Moreau, John W.

    2015-01-01

    Coastal acid sulfate soils (CASS) constitute a serious and global environmental problem. Oxidation of iron sulfide minerals exposed to air generates sulfuric acid with consequently negative impacts on coastal and estuarine ecosystems. Tidal inundation represents one current treatment strategy for CASS, with the aim of neutralizing acidity by triggering microbial iron- and sulfate-reduction and inducing the precipitation of iron-sulfides. Although well-known functional guilds of bacteria drive these processes, their distributions within CASS environments, as well as their relationships to tidal cycling and the availability of nutrients and electron acceptors, are poorly understood. These factors will determine the long-term efficacy of “passive” CASS remediation strategies. Here we studied microbial community structure and functional guild distribution in sediment cores obtained from 10 depths ranging from 0 to 20 cm in three sites located in the supra-, inter- and sub-tidal segments, respectively, of a CASS-affected salt marsh (East Trinity, Cairns, Australia). Whole community 16S rRNA gene diversity within each site was assessed by 454 pyrotag sequencing and bioinformatic analyses in the context of local hydrological, geochemical, and lithological factors. The results illustrate spatial overlap, or close association, of iron-, and sulfate-reducing bacteria (SRB) in an environment rich in organic matter and controlled by parameters such as acidity, redox potential, degree of water saturation, and mineralization. The observed spatial distribution implies the need for empirical understanding of the timing, relative to tidal cycling, of various terminal electron-accepting processes that control acid generation and biogeochemical iron and sulfur cycling. PMID:26191042

  14. Spatial impacts of inorganic ligand availability and localized microbial community structure on mitigation of zinc laden mine water in sulfate-reducing bioreactors.

    Science.gov (United States)

    Drennan, Dina M; Almstrand, Robert; Ladderud, Jeffrey; Lee, Ilsu; Landkamer, Lee; Figueroa, Linda; Sharp, Jonathan O

    2017-05-15

    Sulfate-reducing bioreactors (SRBRs) represent a passive, sustainable, and long-term option for mitigating mining influenced water (MIW) during release. Here we investigate spatial zinc precipitation profiles as influenced by substrate differentiation, inorganic ligand availability (inorganic carbon and sulfide), and microbial community structure in pilot-scale SRBR columns fed with sulfate and zinc-rich MIW. Through a combination of aqueous sampling, geochemical digests, electron microscopy and energy-dispersive x-ray spectroscopy, we were able to delineate zones of enhanced zinc removal, identify precipitates of varying stability, and discern the temporal and spatial evolution of zinc, sulfur, and calcium associations. These geochemical insights revealed spatially variable immobilization regimes between SRBR columns that could be further contrasted as a function of labile (alfalfa-dominated) versus recalcitrant (woodchip-dominated) solid-phase substrate content. Both column subsets exhibited initial zinc removal as carbonates; however precipitation in association with labile substrates was more pronounced and dominated by metal-sulfide formation in the upper portions of the down flow columns with micrographs visually suggestive of sphalerite (ZnS). In contrast, a more diffuse and lower mass of zinc precipitation in the presence of gypsum-like precipitates occurred within the more recalcitrant column systems. While removal and sulfide-associated precipitation were spatially variable, whole bacterial community structure (ANOSIM) and diversity estimates were comparatively homogeneous. However, two phyla exhibited a potentially selective relationship with a significant positive correlation between the ratio of Firmicutes to Bacteroidetes and sulfide-bound zinc. Collectively these biogeochemical insights indicate that depths of maximal zinc sulfide precipitation are temporally dynamic, influenced by substrate composition and broaden our understanding of bio

  15. Multi-scale modeling of Arabidopsis thaliana response to different CO2 conditions: From gene expression to metabolic flux.

    Science.gov (United States)

    Liu, Lin; Shen, Fangzhou; Xin, Changpeng; Wang, Zhuo

    2016-01-01

    Multi-scale investigation from gene transcript level to metabolic activity is important to uncover plant response to environment perturbation. Here we integrated a genome-scale constraint-based metabolic model with transcriptome data to explore Arabidopsis thaliana response to both elevated and low CO2 conditions. The four condition-specific models from low to high CO2 concentrations show differences in active reaction sets, enriched pathways for increased/decreased fluxes, and putative post-transcriptional regulation, which indicates that condition-specific models are necessary to reflect physiological metabolic states. The simulated CO2 fixation flux at different CO2 concentrations is consistent with the measured Assimilation-CO2intercellular curve. Interestingly, we found that reactions in primary metabolism are affected most significantly by CO2 perturbation, whereas secondary metabolic reactions are not influenced a lot. The changes predicted in key pathways are consistent with existing knowledge. Another interesting point is that Arabidopsis is required to make stronger adjustment on metabolism to adapt to the more severe low CO2 stress than elevated CO2 . The challenges of identifying post-transcriptional regulation could also be addressed by the integrative model. In conclusion, this innovative application of multi-scale modeling in plants demonstrates potential to uncover the mechanisms of metabolic response to different conditions. © 2015 Institute of Botany, Chinese Academy of Sciences.

  16. Hormonal and metabolic responses to repeated cycling sprints under different hypoxic conditions.

    Science.gov (United States)

    Kon, Michihiro; Nakagaki, Kohei; Ebi, Yoshiko; Nishiyama, Tetsunari; Russell, Aaron P

    2015-06-01

    Sprint exercise and hypoxic stimulus during exercise are potent factors affecting hormonal and metabolic responses. However, the effects of different hypoxic levels on hormonal and metabolic responses during sprint exercise are not known. Here, we examined the effect of different hypoxic conditions on hormonal and metabolic responses during sprint exercise. Seven male subjects participated in three experimental trials: 1) sprint exercise under normoxia (NSE); 2) sprint exercise under moderate normobaric hypoxia (16.4% oxygen) (HSE 16.4); and 3) sprint exercise under severe normobaric hypoxia (13.6% oxygen) (HSE 13.6). The sprint exercise consisted of four 30s all-out cycling bouts with 4-min rest between bouts. Glucose, free fatty acids (FFA), blood lactate, growth hormone (GH), epinephrine (E), norepinephrine (NE), and insulin concentrations in the HSE trials were measured before exposure to hypoxia (pre 1), 15 min after exposure to hypoxia (pre 2), and at 0, 15, 30, 60, 120, and 180 min after the exercise performed in hypoxia. The blood samples in the NSE trial were obtained in normoxia at the same time points as the HSE trials. Circulating levels of glucose, FFA, lactate, GH, E, NE, and insulin significantly increased after all three exercise trials (P HSE 13.6 trial than in the NSE and HSE 16.4 trials (P < 0.05). A maximal increase in FFA concentration was observed at 180 min after exercise and was not different between trials. These findings suggest that severe hypoxia may be an important factor for the enhancement of GH response to all-out sprint exercise. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Extreme hypoxic conditions induce selective molecular responses and metabolic reset in detached apple fruit

    Directory of Open Access Journals (Sweden)

    Dubravka eCukrov

    2016-02-01

    Full Text Available The ripening physiology of detached fruit is altered by low oxygen conditions with profound effects on quality parameters. To study hypoxia-related processes and regulatory mechanisms, apple (Malus domestica, cv Granny Smith fruit, harvested at commercial ripening, were kept at 1°C under normoxic (control and hypoxic (0.4 and 0.8 kPa oxygen conditions for up to 60 days. NMR analyses of cortex tissue identified eight metabolites showing significantly different accumulations between samples, with ethanol and alanine displaying the most pronounced difference between hypoxic and normoxic treatments A rapid up-regulation of alcohol dehydrogenase and pyruvate-related metabolism (lactate dehydrogenase, pyruvate decarboxylase, alanine aminotransferase gene expression was detected under both hypoxic conditions with a more pronounced effect induced by the lowest (0.4 kPa oxygen concentration. Both hypoxic conditions negatively affected ACC synthase and ACC oxidase transcript accumulation. Analysis of RNA-seq data of samples collected after 24 days of hypoxic treatment identified more than 1,000 genes differentially expressed when comparing 0.4 vs 0.8 kPa oxygen concentration samples. Genes involved in cell-wall, minor and major CHO, amino acid and secondary metabolisms, fermentation and glycolysis as well as genes involved in transport, defense responses and oxidation-reduction appeared to be selectively affected by treatments. The lowest oxygen concentration induced a higher expression of transcription factors belonging to AUX/IAA, WRKY, HB, Zinc-finger families, while MADS box family genes were more expressed when apples were kept under 0.8 kPa oxygen. Out of the eight group VII ERF members present in apple genome, two genes showed a rapid up-regulation under hypoxia, and western blot analysis showed that apple MdRAP2.12 proteins were differentially accumulated in normoxic and hypoxic samples, with the highest level reached under 0.4 kPa oxygen. These

  18. Studying of a wave activity condition and cellular metabolism of tissues in patients with perioral dermatitis

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    Grashkin V.A.

    2012-06-01

    Full Text Available

    Perioral dermatitis is a facial skin disease with insuffciently studied ethiology and pathogenetic mechanisms, being one of actual problems of dermatology. It is a chronic relapsing facial skin disease mainly in women of young and middle age (in men and children meets less often. The disease has an independent clinical picture which is different from rosacea, demodecosis, seborrheic dermatitis, etc. The standard diagnostic criterion is a visual estimation of expression of an infammation on the basis of signs of exudative reaction which has a subjective character. Possibilities of a radiometric method for an objective estimation of a facial skin functional condition and indicators of an intracellular metabolism in patients with a perioral dermatitis were frst studied.

  19. Microbial community structures and in situ sulfate-reducing and sulfur-oxidizing activities in biofilms developed on mortar specimens in a corroded sewer system.

    Science.gov (United States)

    Satoh, Hisashi; Odagiri, Mitsunori; Ito, Tsukasa; Okabe, Satoshi

    2009-10-01

    Microbially induced concrete corrosion (MICC) caused by sulfuric acid attack in sewer systems has been a serious problem for a long time. A better understanding of microbial community structures of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) and their in situ activities is essential for the efficient control of MICC. In this study, the microbial community structures and the in situ hydrogen sulfide production and consumption rates within biofilms and corroded materials developed on mortar specimens placed in a corroded manhole was investigated by culture-independent 16S rRNA gene-based molecular techniques and microsensors for hydrogen sulfide, oxygen, pH and the oxidation-reduction potential. The dark-gray gel-like biofilm was developed in the bottom (from the bottom to 4 cm) and the middle (4-20 cm from the bottom of the manhole) parts of the mortar specimens. White filamentous biofilms covered the gel-like biofilm in the middle part. The mortar specimens placed in the upper part (30 cm above the bottom of the manhole) were corroded. The 16S rRNA gene-cloning analysis revealed that one clone retrieved from the bottom biofilm sample was related to an SRB, 12 clones and 6 clones retrieved from the middle biofilm and the corroded material samples, respectively, were related to SOB. In situ hybridization results showed that the SRB were detected throughout the bottom biofilm and filamentous SOB cells were mainly detected in the upper oxic layer of the middle biofilm. Microsensor measurements demonstrated that hydrogen sulfide was produced in and diffused out of the bottom biofilms. In contrast, in the middle biofilm the hydrogen sulfide produced in the deeper parts of the biofilm was oxidized in the upper filamentous biofilm. pH was around 3 in the corroded materials developed in the upper part of the mortar specimens. Therefore, it can be concluded that hydrogen sulfide provided from the bottom biofilms and the sludge settling tank was

  20. Metabolic Flux Analysis of the Synechocystis sp. PCC 6803 ΔnrtABCD Mutant Reveals a Mechanism for Metabolic Adaptation to Nitrogen-Limited Conditions.

    Science.gov (United States)

    Nakajima, Tsubasa; Yoshikawa, Katsunori; Toya, Yoshihiro; Matsuda, Fumio; Shimizu, Hiroshi

    2017-03-01

    Metabolic flux redirection during nitrogen-limited growth was investigated in the Synechocystis sp. PCC 6803 glucose-tolerant (GT) strain under photoautotrophic conditions by isotopically non-stationary metabolic flux analysis (INST-MFA). A ΔnrtABCD mutant of Synechocystis sp. PCC 6803 was constructed to reproduce phenotypes arising during nitrogen starvation. The ΔnrtABCD mutant and the wild-type GT strain were cultured under photoautotrophic conditions by a photobioreactor. Intracellular metabolites were labeled over a time course using NaH13CO3 as a carbon source. Based on these data, the metabolic flux distributions in the wild-type and ΔnrtABCD cells were estimated by INST-MFA. The wild-type GT and ΔnrtABCD strains displayed similar distribution patterns, although the absolute levels of metabolic flux were lower in ΔnrtABCD. Furthermore, the relative flux levels for glycogen metabolism, anaplerotic reactions and the oxidative pentose phosphate pathway were increased in ΔnrtABCD. This was probably due to the increased expression of enzyme genes that respond to nitrogen depletion. Additionally, we found that the ratio of ATP/NADPH demand increased slightly in the ΔnrtABCD mutant. These results indicated that futile ATP consumption increases under nitrogen-limited conditions because the Calvin-Benson cycle and the oxidative pentose phosphate pathway form a metabolic futile cycle that consumes ATP without CO2 fixation and NADPH regeneration. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Real-Time PCR Quantification and Diversity Analysis of the Functional Genes aprA and dsrA of Sulfate-Reducing Prokaryotes in Marine Sediments of the Peru Continental Margin and the Black Sea

    OpenAIRE

    Blazejak, Anna; Schippers, Axel

    2011-01-01

    Sulfate-reducing prokaryotes (SRP) are ubiquitous and quantitatively important members in many ecosystems, especially in marine sediments. However their abundance and diversity in subsurface marine sediments is poorly understood. In this study, the abundance and diversity of the functional genes for the enzymes adenosine 5′-phosphosulfate reductase (aprA) and dissimilatory sulfite reductase (dsrA) of SRP in marine sediments of the Peru continental margin and the Black Sea were analyzed, inclu...

  2. Genetic background and environmental conditions drive metabolic variation in wild type and transgenic soybean (Glycine max) seeds.

    Science.gov (United States)

    Cohen, Hagai; Shir, Ofer M; Yu, Yang; Hou, Wensheng; Sun, Shi; Han, Tianfu; Amir, Rachel

    2016-08-01

    The metabolic profiles and composition of storage reserves of agricultural crop seeds are strongly regulated by heritable and environmental factors. Yet, very little is known about the genetic and environmental determinants of adaptive metabolic variation amongst wild type as well as transgenic seed populations derived from the same genetic background, grown under natural field conditions. The goal of the current study was to investigate the effects of natural environmental conditions on wild type and transgenic soybean seeds expressing a feedback-insensitive form of cystathionine γ-synthase, a methionine main regulatory enzyme. The seeds were grown in four geographically distinct habitats in China and then assayed for primary metabolic profiles using gas chromatography mass spectrometry, morphological traits and storage reserve accumulation. The analyses revealed changes in the levels of primary metabolites which evidently exhibited high correlation to methionine regardless of changes in environmental conditions. The environment, however, constituted a major determinant of metabolic profiles amongst seeds, as much more metabolites were observed to be affected by this variable, particularly along the north-to-south latitudinal gradient. The observations suggest that metabolic variation amongst seeds grown under natural field conditions depends upon the complex relationships existing amongst their genetic background and the environmental conditions characterizing their cultivation areas. © 2016 John Wiley & Sons Ltd.

  3. Metabolic Profile and Inflammatory Responses in Dairy Cows with Left Displaced Abomasum Kept under Small-Scaled Farm Conditions

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    Fenja Klevenhusen

    2015-10-01

    Full Text Available Left displaced abomasum (LDA is a severe metabolic disease of cattle with a strong negative impact on production efficiency of dairy farms. Metabolic and inflammatory alterations associated with this disease have been reported in earlier studies, conducted mostly in large dairy farms. This research aimed to: (1 evaluate metabolic and inflammatory responses in dairy cows affected by LDA in small-scaled dairy farms; and (2 establish an Animals 2015, 5 1022 association between lactation number and milk production with the outcome of metabolic variables. The cows with LDA had lower serum calcium (Ca, but greater concentrations of non-esterified fatty acids (NEFA and beta-hydroxy-butyrate (BHBA, in particular when lactation number was >2. Cows with LDA showed elevated levels of aspartate aminotransferase, glutamate dehydrogenase, and serum amyloid A (SAA, regardless of lactation number. In addition, this study revealed strong associations between milk yield and the alteration of metabolic profile but not with inflammation in the sick cows. Results indicate metabolic alterations, liver damage, and inflammation in LDA cows kept under small-scale farm conditions. Furthermore, the data suggest exacerbation of metabolic profile and Ca metabolism but not of inflammation and liver health with increasing lactation number and milk yield in cows affected by LDA.

  4. The free NADH concentration is kept constant in plant mitochondria under different metabolic conditions

    DEFF Research Database (Denmark)

    Kasimova, M.R.; Grigiene, J.; Krab, K.

    2006-01-01

    with fluorescence spectroscopy. The NADH content of actively respiring mitochondria (from potato tubers [Solanum tuberosum cv Bintje]) in different metabolic states was then measured by spectral decomposition analysis of fluorescence emission spectra. Most of the mitochondrial NADH is bound to proteins...... metabolism. These findings have far-reaching consequences for the interpretation of cellular metabolism....

  5. Modifications of xyloglucan metabolism in azuki bean epicotyls under hypergravity conditions

    Science.gov (United States)

    Soga, Kouichi; Arai, Kuninori; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

    We examined the effects of hypergravity on both the synthesis and the depolymerization processes of xyloglucan metabolisms. Azuki bean cuttings were incubated with [6-3H]-L-fucose, and the levels and the molecular size of synthesized xyloglucans were investigated in the upper growing regions of epicotyls. The amounts of radioactivity incorporated into xyloglucan fraction increased during incubation, irrespective of the gravity conditions. 3H-Xyloglucans were eluted in the higher molecular mass regions than xyloglucans already present in the cell wall. Hypergravity at 300 g did not influence the molecular size of newly deposited xyloglucans. Thus, the process of xyloglucan synthesis was not modified by the gravitational force. On the other hand, 3H-xyloglucans obtained from epicotyls grown at 1 g were shifted to the low molecular mass regions during the incubation period, which was inhibited by hypergravity. These results indicate that xyloglucans were deposited into the cell wall as large molecules but they were then depolymerized in the cell wall, and that the inhibition of the depolymerization is mainly responsible for the increase in the molecular size of xyloglucans under hypergravity conditions.

  6. Recombinant E. coli expressing Vitreoscilla haemoglobin prefers aerobic metabolism under microaerobic conditions: a proteome-level study.

    Science.gov (United States)

    Ramachandran, Bini; Dikshit, Kanak Lata; Dharmalingam, Kuppamuthu

    2012-09-01

    Vitreoscilla haemoglobin (VHb) expression in heterologous host was shown to enhance growth and oxygen utilization capabilities under oxygen-limited conditions. The exact mechanism by which VHb enhances the oxygen utilization under oxygen-limiting conditions is still unknown. In order to understand the role of VHb in promoting oxygen utilization, changes in the total protein profile of E. coli expressing the vgb gene under its native promoter was analysed. Two-dimensional difference gel electrophoresis (2D DIGE) was employed to quantify the differentially expressed proteins under oxygen-limiting conditions. Overexpression of proteins involved in aerobic metabolic pathways and suppression of proteins involved in non-oxidative metabolic pathways shown in this study indicates that the cells expressing VHb prefer aerobic metabolic pathways even under oxygen limitation. Under these conditions, the expression levels of proteins involved in central metabolic pathways, cellular adaptation and cell division were also found to be altered. These results imply that Vitreoscilla haemoglobin expression alters aerobic metabolism specifically, in addition to altering proteins involved in other pathways, the significance of which is not clear as of now.

  7. Effects of Long-Term Acid-Mine Drainage Contamination on Diversity and Activity of Sulfate-Reducing Bacteria in a Natural Salt Marsh.

    Science.gov (United States)

    Moreau, J. W.; Banfield, J. F.

    2003-12-01

    Constructed wetlands have been studied as sites or analogs for in situ bioremediation of metal contaminants from acid mine drainage (AMD) or industrial sources (e.g. Webb et al. 1998). Wetlands bioremediation necessarily invokes the ubiquity and robustness of sulfate-reducing bacteria (SRB) to sequester dissolved metals into various poorly soluble metal-sulfides (e.g. PbS, CdS). However, few studies of natural wetlands under long-term ecological forcing by AMD or other contaminant sources are available for context. We are investigating the microbial diversity, mineralogy and geochemistry of a highly contaminated salt marsh along the East Central San Francisco Bay. For nearly a half-century, areas within this marsh have received acidic and/or metal-rich groundwaters from near-surface pyrite tailings (transported there from Iron Mountain Mine, near Redding, CA) and local industrial sources (e.g. paint and explosives manufacturers). Sediment cores (30-40 cm long) were taken from six contaminated sites in the marsh with pH range of ˜2 to ˜8. Previous analyses (URS Corp. 2001) reported As, Cd, Cu, Se, Zn, and Pb present in sediments at extremely high concentrations (100s of ppm), yet our ICP-AES analyses of pore waters showed only As present at concentrations of 10-50 ppb. We infer, from high-resolution transmission electron microscope (HRTEM) studies of biogenic (SRB biofilm) ZnS (Moreau et al. 2003, in review) and marsh sediments, that contaminant metals have been sequestered into aggregates of nanocrystalline metal-sulfides. Continuous-flow isotope ratio mass spectrometer (CF-IRMS) analyses of pore-water sulfate and sedimentary sulfides allow resolution of contributions to dissolved sulfate and sulfide from tailings oxidation and dissimilatory sulfate reduction. Sulfate analyses from subsections of three cores (pH 2-3, 6-7, 7-8, respectively) all yield δ 34S values consistent with bacterial sulfate reduction. We note that all three cores also contain very fine

  8. Vanillin production using metabolically engineered Escherichia coli under non-growing conditions

    Directory of Open Access Journals (Sweden)

    Fava Fabio

    2007-04-01

    Full Text Available Abstract Background Vanillin is one of the most important aromatic flavour compounds used in the food and cosmetic industries. Natural vanillin is extracted from vanilla beans and is relatively expensive. Moreover, the consumer demand for natural vanillin highly exceeds the amount of vanillin extracted by plant sources. This has led to the investigation of other routes to obtain this flavour such as the biotechnological production from ferulic acid. Studies concerning the use of engineered recombinant Escherichia coli cells as biocatalysts for vanillin production are described in the literature, but yield optimization and biotransformation conditions have not been investigated in details. Results Effect of plasmid copy number in metabolic engineering of E. coli for the synthesis of vanillin has been evaluated by the use of genes encoding feruloyl-CoA synthetase and feruloyl hydratase/aldolase from Pseudomonas fluorescens BF13. The higher vanillin production yield was obtained using resting cells of E. coli strain JM109 harbouring a low-copy number vector and a promoter exhibiting a low activity to drive the expression of the catabolic genes. Optimization of the bioconversion of ferulic acid to vanillin was accomplished by a response surface methodology. The experimental conditions that allowed us to obtain high values for response functions were 3.3 mM ferulic acid and 4.5 g/L of biomass, with a yield of 70.6% and specific productivity of 5.9 μmoles/g × min after 3 hours of incubation. The final concentration of vanillin in the medium was increased up to 3.5 mM after a 6-hour incubation by sequential spiking of 1.1 mM ferulic acid. The resting cells could be reused up to four times maintaining the production yield levels over 50%, thus increasing three times the vanillin obtained per gram of biomass. Conclusion Ferulic acid can be efficiently converted to vanillin, without accumulation of undesirable vanillin reduction/oxidation products

  9. EXTREME METEOROLOGICAL CONDITIONS AND METABOLIC PROFILE IN HIGH YIELDING HOLSTEINFRIESIAN DAIRY COWS

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    Z. GERGÁCZ

    2008-10-01

    Full Text Available The impact of two years (2002 and 2003 with different summer temperature extremes on variation in metabolic profile was analyzed in blood and urine samples taken from healthy, primiparous (n = 371 and multiparous (n = 795 high yielding Holstein-Friesian dairy cows. In this study main focus was lead on three most critical physiological phases, thus cows were assigned into three groups as follows: (1 dry cows for 10 days prior to calving; (2 cows 1-30 days after delivery, and (3 cows with more than 31 days post partum. Findings reveal clear response of the cows to heat in selected blood (hemoglobin, plasma aceto-acetic-acid, FFA, AST, glucose, urea and urine (pH, NABE and urea parameters. In the majority of cows, glucose and hemoglobin level, one of the most significant blood parameters, indicated symptoms of insufficient energy supply. Further metabolic indicators differed more or less from reference values depending on actual condition. Due to heat load dry matter intake has been decreased even by 10-15 per cent in primiparous cows. They were expected to increase body weight and size and simultaneously produce attain at large milk yields. In doing so that cows would have require large amount of nutrients. Out of parameters such as hemoglobin, glucose, FFA, AST and blood-urea differed from the reference values in most cases; however, this phenomenon seemed to be present in almost every case for hemoglobin and glucose. The lack of energy caused by heat stress can be contributed to the decrease of dry matter intake which has been indicated by the urea levels and pH both in blood and urine prevailing unfavorable and insufficient feeding practice. The results reconfirm the need to reconsider both the actual feeding practice (e.g. to increase of nutrient content in rations, reduce the intake of soluble proteins in rumen, pay attention of crude fiber in Total Mixed Rations (TMR, NDF and ADF, avoid overfeeding of inorganic buffers, to control moisture

  10. Sensing technologies to measure metabolic activities in soil and assess its health conditions

    Science.gov (United States)

    De Cesare, Fabrizio; Macagnano, Antonella

    2013-04-01

    (olfactory fingerprint) typical of the analysed air sample. Due to these features, we decided to apply such a sensing technology to the analyses of soil atmospheres, because several processes in soil, both abiotic and biotic, result in gas and/or volatile production and the dynamics of such releases may also be affected by several additional environmental factors, such as soil moisture, temperature, gas exchange rates with outer atmosphere, adsorption/desorption processes, etc. Then, the analysis of soil atmosphere may provide information about global soil conditions (e.g. soil quality and health), according to a holistic approach, where several factors are contemporarily taken into account. At the same time, the use of such a technology, if adequately trained on purpose, can supply information about a single or a pool of processes sharing similar features, which occur in soil over a certain period of time and mostly affecting soil atmosphere. According to these premises and hypotheses, we demonstrated that EN is an useful technology to measure soil microbial activity, through its correlation to specific metabolic activities occurring in soil (i.e. global and specific respiration and some enzyme activities), but also soil microbial biomass. On the basis of such evidences, we also were able to use this technology to assess the quality and health conditions of soil ecosystems in terms of metabolic indices previously identified, according to some metabolic parameters and biomass quantification of microbial populations. In other studies, we also applied EN technology, despite using a different set of sensors in the array, to analyse the atmosphere of soil ecosystems in order to assess their environmental conditions after contamination with polycyclic aromatic hydrocarbons (PAHs) (i.e. semivolatile - SVOCs - organic pollutants). In this case, EN technology resulted capable of distinguishing between contaminated and uncontaminated soils, according to the differences in a list of

  11. Identification of key factors in Accelerated Low Water Corrosion through experimental simulation of tidal conditions: influence of stimulated indigenous microbiota.

    Science.gov (United States)

    Marty, Florence; Gueuné, Hervé; Malard, Emilie; Sánchez-Amaya, José M; Sjögren, Lena; Abbas, Ben; Quillet, Laurent; van Loosdrecht, Mark C M; Muyzer, Gerard

    2014-01-01

    Biotic and abiotic factors favoring Accelerated Low Water Corrosion (ALWC) on harbor steel structures remain unclear warranting their study under controlled experimental tidal conditions. Initial stimulation of marine microbial consortia by a pulse of organic matter resulted in localized corrosion and the highest corrosion rates (up to 12-times higher than non-stimulated conditions) in the low water zone, persisting after nine months exposure to natural seawater. Correlations between corrosion severity and the abundance and composition of metabolically active sulfate-reducing bacteria (SRB) indicated the importance and persistence of specific bacterial populations in accelerated corrosion. One phylotype related to the electrogenic SRB Desulfopila corrodens appeared as the major causative agent of the accelerated corrosion. The similarity of bacterial populations related to sulfur and iron cycles, mineral and tuberculation with those identified in ALWC support the relevance of experimental simulation of tidal conditions in the management of steel corrosion exposed to harbor environments.

  12. Transcriptomic and proteomic responses of Serratia marcescens to spaceflight conditions involve large-scale changes in metabolic pathways

    Science.gov (United States)

    Wang, Yajuan; Yuan, Yanting; Liu, Jinwen; Su, Longxiang; Chang, De; Guo, Yinghua; Chen, Zhenhong; Fang, Xiangqun; Wang, Junfeng; Li, Tianzhi; Zhou, Lisha; Fang, Chengxiang; Yang, Ruifu; Liu, Changting

    2014-04-01

    The microgravity environment of spaceflight expeditions has been associated with altered microbial responses. This study explores the characterization of Serratia marcescensis grown in a spaceflight environment at the phenotypic, transcriptomic and proteomic levels. From November 1, 2011 to November 17, 2011, a strain of S. marcescensis was sent into space for 398 h on the Shenzhou VIII spacecraft, and ground simulation was performed as a control (LCT-SM213). After the flight, two mutant strains (LCT-SM166 and LCT-SM262) were selected for further analysis. Although no changes in the morphology, post-culture growth kinetics, hemolysis or antibiotic sensitivity were observed, the two mutant strains exhibited significant changes in their metabolic profiles after exposure to spaceflight. Enrichment analysis of the transcriptome showed that the differentially expressed genes of the two spaceflight strains and the ground control strain mainly included those involved in metabolism and degradation. The proteome revealed that changes at the protein level were also associated with metabolic functions, such as glycolysis/gluconeogenesis, pyruvate metabolism, arginine and proline metabolism and the degradation of valine, leucine and isoleucine. In summary S. marcescens showed alterations primarily in genes and proteins that were associated with metabolism under spaceflight conditions, which gave us valuable clues for future research.

  13. Real-time PCR quantification and diversity analysis of the functional genes aprA and dsrA of sulfate-reducing bacteria in marine sediments of the Peru continental margin and the Black Sea

    OpenAIRE

    Axel eSchippers; Anna eBlazejak

    2011-01-01

    A quantitative, real-time PCR (Q-PCR) assay for the functional gene adenosine 5´-phosphosulfate reductase (aprA) of sulfate-reducing bacteria (SRB) was designed. This assay was applied together with described Q-PCR assays for dissimilatory sulfite reductase (dsrA) and the 16S rRNA gene of total Bacteria to marine sediments from the Peru margin (0 – 121 meters below seafloor (mbsf)) and the Black Sea (0 – 6 mbsf). Clone libraries of aprA show that all isolated sequences originate from SRB...

  14. Biochemical Mechanisms and Microorganisms Involved in Anaerobic Testosterone Metabolism in Estuarine Sediments

    Directory of Open Access Journals (Sweden)

    Chao-Jen Shih

    2017-08-01

    Full Text Available Current knowledge on the biochemical mechanisms underlying microbial steroid metabolism in anaerobic ecosystems is extremely limited. Sulfate, nitrate, and iron [Fe (III] are common electron acceptors for anaerobes in estuarine sediments. Here, we investigated anaerobic testosterone metabolism in anaerobic sediments collected from the estuary of Tamsui River, Taiwan. The anaerobic sediment samples were spiked with testosterone (1 mM and individual electron acceptors (10 mM, including nitrate, Fe3+, and sulfate. The analysis of androgen metabolites indicated that testosterone biodegradation under denitrifying conditions proceeds through the 2,3-seco pathway, whereas testosterone biodegradation under iron-reducing conditions may proceed through an unidentified alternative pathway. Metagenomic analysis and PCR-based functional assays suggested that Thauera spp. were the major testosterone degraders in estuarine sediment samples incubated with testosterone and nitrate. Thauera sp. strain GDN1, a testosterone-degrading betaproteobacterium, was isolated from the denitrifying sediment sample. This strain tolerates a broad range of salinity (0–30 ppt. Although testosterone biodegradation did not occur under sulfate-reducing conditions, we observed the anaerobic biotransformation of testosterone to estrogens in some testosterone-spiked sediment samples. This is unprecedented since biotransformation of androgens to estrogens is known to occur only under oxic conditions. Our metagenomic analysis suggested that Clostridium spp. might play a role in this anaerobic biotransformation. These results expand our understanding of microbial metabolism of steroids under strictly anoxic conditions.

  15. Does air-breathing meet metabolic demands of the juvenile snakehead, Channa argus, in multiple conditions

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    Yongli Li

    2017-05-01

    Full Text Available The objective of this study was to examine how the respiratory metabolism of the snakehead Channa argus changed when it shifted from breathing water to breathing air, and how increased metabolic demands caused by temperature, feeding, and exhaustive exercise affect its survival in air. The results demonstrated that the oxygen consumption rate (MO2 of the snakehead was lower for aerial respiration than aquatic respiration by 12.1, 24.5 and 20.4% at 20, 25, and 30°C, respectively. Survival time was significantly shortened with increasing temperature and was negatively correlated with the resting MO2 in air (MO2Air. No obvious feeding metabolic response was observed in the snakeheads fed at 1% and 3% body mass levels while breathing air. The maximum MO2Air of the snakehead after exhaustive exercise was significantly higher than the resting MO2Air of the control group. The results suggest that the snakehead could survive out of water by breathing air for varying lengths of time, depending on ambient temperature and metabolic demand. Additionally, some degree of metabolic depression occurs in the snakehead when breathing air. The metabolic demand associated with exercise in the snakehead, but not that associated with feeding, can be supported by its capacity for breathing air to some extent.

  16. Lymphocytes Mitochondrial Physiology as Biomarker of Energy Metabolism during Fasted and Fed Conditions

    Directory of Open Access Journals (Sweden)

    Erika Cortez

    2012-01-01

    Full Text Available Mitochondria are central coordinators of energy metabolism, and changes of their physiology have long been associated with metabolic disorders. Thus, observations of energy dynamics in different cell types are of utmost importance. Therefore, tools with quick and easy handling are needed for consistent evaluations of such interventions. In this paper, our main hypothesis is that during different nutritional situations lymphocytes mitochondrial physiology could be associated with the metabolism of other cell types, such as cardiomyocytes, and consequently be used as metabolic biomarker. Blood lymphocytes and heart muscle fibers were obtained from both fed and 24 h-fasted mice, and mitochondrial analysis was assessed by high-resolution respirometry and western blotting. Carbohydrate-linked oxidation and fatty acid oxidation were significantly higher after fasting. Carnitine palmitoil transferase 1 and uncouple protein 2 contents were increased in the fasted group, while the glucose transporters 1 and 4 and the ratio phosphorylated AMP-activated protein kinase/AMPK did not change between groups. In summary, under a nutritional status modification, mitochondria demonstrated earlier adaptive capacity than other metabolic sensors such as glucose transporters and AMPK, suggesting the accuracy of mitochondria physiology of lymphocytes as biomarker for metabolic changes.

  17. Metabolic analysis of adaptation to short-term changes in culture conditions of the marine diatom Thalassiosira pseudonana.

    Directory of Open Access Journals (Sweden)

    Mariusz A Bromke

    Full Text Available This report describes the metabolic and lipidomic profiling of 97 low-molecular weight compounds from the primary metabolism and 124 lipid compounds of the diatom Thalassiosira pseudonana. The metabolic profiles were created for diatoms perturbed for 24 hours with four different treatments: (I removal of nitrogen, (II lower iron concentration, (III addition of sea salt, (IV addition of carbonate to their growth media. Our results show that as early as 24 hours after nitrogen depletion significant qualitative and quantitative change in lipid composition as well as in the primary metabolism of Thalassiosira pseudonana occurs. So we can observe the accumulation of several storage lipids, namely triacylglycerides, and TCA cycle intermediates, of which citric acid increases more than 10-fold. These changes are positively correlated with expression of TCA enzymes genes. Next to the TCA cycle intermediates and storage lipid changes, we have observed decrease in N-containing lipids and primary metabolites such as amino acids. As a measure of counteracting nitrogen starvation, we have observed elevated expression levels of nitrogen uptake and amino acid biosynthetic genes. This indicates that diatoms can fast and efficiently adapt to changing environment by altering the metabolic fluxes and metabolite abundances. Especially, the accumulation of proline and the decrease of dimethylsulfoniopropionate suggest that the proline is the main osmoprotectant for the diatom in nitrogen rich conditions.

  18. Associations of self-reported periodontal disease with metabolic syndrome and number of self-reported chronic conditions.

    Science.gov (United States)

    Bensley, Lillian; VanEenwyk, Juliet; Ossiander, Eric M

    2011-05-01

    Increasing evidence supports associations between periodontal disease and various chronic conditions. Possible explanations include chronic inflammatory processes, shared pathogens, and shared risk factors, such as smoking and psychosocial stress. The objective of this study was to assess associations of periodontal disease with metabolic syndrome and number of chronic diseases. As part of the Washington Adult Health Survey, a household-based cross-sectional study conducted during 2006-2007 among adults aged 25 years or older in Washington State, we collected questionnaire data, blood samples, and anthropometric measures. We used these data to assess associations of periodontal disease with metabolic syndrome and the number of self-reported chronic diseases, controlling for age, sex, annual household income, smoking, and psychosocial stress. We used both complete case and multiple imputation Poisson regression analyses. In the adjusted complete case analysis, 1.4 times as many chronic conditions were found among people with severe compared with no periodontal disease, and people with severe periodontal disease were 1.5 times more likely to have metabolic syndrome than people with no periodontal disease. Arthritis and liver disease were individually associated with severe periodontal disease. Results of the multiple imputation analyses were similar. These results suggest that people with severe periodontal disease are likely to have more chronic diseases and are more likely to have metabolic syndrome compared with people without periodontal disease. Research about the effectiveness of periodontal treatment to help prevent or control chronic diseases is needed.

  19. Associations of Self-Reported Periodontal Disease With Metabolic Syndrome and Number of Self-Reported Chronic Conditions

    OpenAIRE

    Bensley, Lillian; VanEenwyk, Juliet; Ossiander, Eric M.

    2011-01-01

    Introduction Increasing evidence supports associations between periodontal disease and various chronic conditions. Possible explanations include chronic inflammatory processes, shared pathogens, and shared risk factors, such as smoking and psychosocial stress. The objective of this study was to assess associations of periodontal disease with metabolic syndrome and number of chronic diseases. Methods As part of the Washington Adult Health Survey, a household-based cross-sectional study conduct...

  20. Glucose metabolism in Lactococcus lactis MG1363 under different aeration conditions: Requirement of acetate to sustain growth under microaerobic conditions

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Jensen, N.B.S.; Villadsen, John

    2003-01-01

    resulted in acetate, CO2, and acetoin replacing formate and ethanol as end products. Under microaerobic conditions, growth came to a gradual halt, although more than 60% of the glucose was still left. A decline in growth was not observed during microaerobic cultivation when acetate was added to the medium....... We hypothesize that the decline in growth was due to a lack of acetyl coenzyme A (acetyl-CoA) needed for fatty acid synthesis since acetyl-CoA can be synthesized from acetate by means of acetate kinase and phosphotransacetylase activities....... with air was used as the reference). The maximum specific growth rate was high (0.78 to 0.91 h(-1)) under all aeration conditions but decreased with increasing aeration, and more than 90% of the glucose was converted to lactate. However, a shift in by-product formation was observed. Increasing aeration...

  1. Protective effect of energy metabolism regulators in alteration of gravitation load under experimental conditions.

    Science.gov (United States)

    Mazina, N K; Larina, I M; Khazanov, V A; Shenkman, B S; Tsapok, P I; Zaitsev, V B; Khorobrykh, V G; Veselova, O M; Tret'yakov, V S

    2006-10-01

    Mitochondrial substrate-based preparations corrected disorders, caused by long-term exposure to abnormal gravitation vector in head-down tilt (hanging) test in rats. The preparations produced systemic and polyorgan protective effects consisting in correction of the blood prooxidant/antioxidant balance, energy metabolism in musculus soleus, and minimization of morphological changes in the liver and kidneys.

  2. Polycystic ovary syndrome: a complex condition with psychological, reproductive and metabolic manifestations that impacts on health across the lifespan

    Science.gov (United States)

    2010-01-01

    Polycystic ovary syndrome (PCOS) is of clinical and public health importance as it is very common, affecting up to one in five women of reproductive age. It has significant and diverse clinical implications including reproductive (infertility, hyperandrogenism, hirsutism), metabolic (insulin resistance, impaired glucose tolerance, type 2 diabetes mellitus, adverse cardiovascular risk profiles) and psychological features (increased anxiety, depression and worsened quality of life). Polycystic ovary syndrome is a heterogeneous condition and, as such, clinical and research agendas are broad and involve many disciplines. The phenotype varies widely depending on life stage, genotype, ethnicity and environmental factors including lifestyle and bodyweight. Importantly, PCOS has unique interactions with the ever increasing obesity prevalence worldwide as obesity-induced insulin resistance significantly exacerbates all the features of PCOS. Furthermore, it has clinical implications across the lifespan and is relevant to related family members with an increased risk for metabolic conditions reported in first-degree relatives. Therapy should focus on both the short and long-term reproductive, metabolic and psychological features. Given the aetiological role of insulin resistance and the impact of obesity on both hyperinsulinaemia and hyperandrogenism, multidisciplinary lifestyle improvement aimed at normalising insulin resistance, improving androgen status and aiding weight management is recognised as a crucial initial treatment strategy. Modest weight loss of 5% to 10% of initial body weight has been demonstrated to improve many of the features of PCOS. Management should focus on support, education, addressing psychological factors and strongly emphasising healthy lifestyle with targeted medical therapy as required. Monitoring and management of long-term metabolic complications is also an important part of routine clinical care. Comprehensive evidence-based guidelines are

  3. [Inborn errors of metabolism are not hopeless; early identification of treatable conditions in children with intellectual disability].

    Science.gov (United States)

    van Karnebeek, Clara D M

    2014-01-01

    Intellectual disability is a devastating condition affecting 2-3% of the global population; comorbidity is common. In addition to its lifelong impact on affected individuals, families and society as a whole, intellectual disability is associated with the highest healthcare costs of any disease. Inborn errors of metabolism constitute a group of rare genetic disorders that commonly manifest as an intellectual disability. For patients with these disorders, an increasing number of treatments are becoming available aimed at the pathophysiological mechanisms. A review of the literature identified 91 treatable inherited metabolic disorders; this was the basis for the development of a step-by-step diagnostic protocol and an app, Treatable-ID. A 2.5-year study in a tertiary setting treatable inborn errors of metabolism were identified as cause of intellectual disability in more than 5% of the children studied. It also showed that implementation of the diagnostic protocol reduced unnecessary costs and diagnostic delay. These results should motivate clinicians to aim diagnostic assessment of an individual with intellectual disability at treatable inborn errors of metabolism. Such an approach prevents brain damage, improves development and health and gives patients hope.

  4. Study of metabolic profile of Rhizopus oryzae to enhance fumaric acid production under low pH condition.

    Science.gov (United States)

    Liu, Ying; Xu, Qing; Lv, Chunwei; Yan, Caixia; Li, Shuang; Jiang, Ling; Huang, He; Ouyang, Pingkai

    2015-12-01

    Ensuring a suitable pH is a major problem in industrial organic acid fermentation. To circumvent this problem, we used a metabolic profiling approach to analyze metabolite changes in Rhizopus oryzae under different pH conditions. A correlation between fumaric acid production and intracellular metabolic characteristics of R. oryzae was revealed by principal component analysis. The results showed that to help cell survival in the presence of low pH, R. oryzae altered amino acid and fatty acid metabolism and promoted sugar or sugar alcohol synthesis, corresponding with a suppressing of energy metabolism, phenylalanine, and tyrosine synthesis and finally resulting in the low performance of fumaric acid production. Based on this observation, 1 % linoleic acid was added to the culture medium in pH 3.0 to decrease the carbon demand for cell survival, and the fumaric acid titer was enhanced by 39.7 % compared with the control (pH 3.0 without linoleic acid addition), reaching 18.3 g/L after 84 h of fermentation. These findings provide new insights into the mechanism by which R. oryzae responds to acidic stress and would be helpful for the development of efficient strategies for fumaric acid production at low pH.

  5. Insulin response of the glucose and fatty acid metabolism in dry dairy cows across a range of body condition scores.

    Science.gov (United States)

    De Koster, J; Hostens, M; Van Eetvelde, M; Hermans, K; Moerman, S; Bogaert, H; Depreester, E; Van den Broeck, W; Opsomer, G

    2015-07-01

    The objective of the present research was to determine the insulin response of the glucose and fatty acid metabolism in dry dairy cows with a variable body condition score (BCS). Ten pregnant Holstein Friesian dairy cows (upcoming parity 2 to 5) were selected based on BCS at the beginning of the study (2mo before expected parturition date). During the study, animals were monitored weekly for BCS and backfat thickness and in the last 2wk, blood samples were taken for determination of serum nonesterified fatty acid (NEFA) concentration. Animals underwent a hyperinsulinemic euglycemic clamp test in the third week before the expected parturition date. The hyperinsulinemic euglycemic clamp test consisted of 4 consecutive insulin infusions with increasing insulin doses: 0.1, 0.5, 2, and 5mIU/kg per minute. For each insulin infusion period, a steady state was defined as a period of 30min where no or minor changes of the glucose infusion were necessary to keep the blood glucose concentration constant and near basal levels. During the steady state, the glucose infusion rate [steady state glucose infusion rate (SSGIR) in µmol/kg per minute] and NEFA concentration [steady state NEFA concentration (SSNEFA) in mmol/L] were determined and reflect the insulin response of the glucose and fatty acid metabolism. Dose response curves were created based on the insulin concentrations during the steady state and the SSGIR or SSNEFA. The shape of the dose response curves is determined by the concentration of insulin needed to elicit the half maximal effect (EC50) and the maximal SSGIR or the minimal SSNEFA for the glucose or fatty acid metabolism, respectively. The maximal SSGIR was negatively associated with variables reflecting adiposity of the cows (BCS, backfat thickness, NEFA concentration during the dry period, and absolute weight of the different adipose depots determined after euthanasia and dissection of the different depots), whereas the EC50 of the glucose metabolism was

  6. Chronic condition as a mediator between metabolic syndrome and cognition among community-dwelling older adults: The moderating role of sex.

    Science.gov (United States)

    Foong, Hui Foh; Hamid, Tengku Aizan; Ibrahim, Rahimah; Haron, Sharifah Azizah; Shahar, Suzana

    2017-11-01

    Metabolic syndrome and chronic conditions are significant predictors of cognition; however, few studies have examined how they work together in predicting cognition in old age. Therefore, the present study examines whether a chronic condition mediates the association between metabolic syndrome and cognition. In addition, it discusses the moderating role of sex in the relationships between metabolic syndrome, chronic conditions and cognition. Secondary analysis was carried out of data from the Malaysian national survey that involved 2322 community residents aged 60 years or older in Peninsular Malaysia. Cognition was measured by the digit symbol substitution test. Metabolic syndrome was assessed by five biomarkers: triglyceride, fasting blood sugar, systolic blood pressure, cholesterol ratio and body mass index. Chronic conditions were assessed by self-reported medical history. The structural equation modeling technique was used to analyze the mediation and moderation tests. The number of chronic conditions partially mediated the association between metabolic syndrome and cognition. Men and women did not differ in the relationship between metabolic syndrome and cognition; however, the number of chronic conditions was found to be negatively associated with cognition in older women, but not in men. Metabolic syndrome might increase the likelihood of older adults to suffer from more chronic conditions; these responses might reduce their cognition. To prevent cognitive decline in old age, specific intervention to minimize the number of chronic conditions by reducing their vascular risk factors is warranted, especially among older women. Geriatr Gerontol Int 2017; 17: 1914-1920. © 2017 Japan Geriatrics Society.

  7. Mannitol metabolism during pathogenic fungal–host interactions under stressed conditions

    Science.gov (United States)

    Meena, Mukesh; Prasad, Vishal; Zehra, Andleeb; Gupta, Vijai K.; Upadhyay, Ram S.

    2015-01-01

    Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; furthermore, mannitol also acts as a powerful quencher of reactive oxygen species (ROS). Some phytopathogenic fungi use mannitol to stifle ROS-mediated plant resistance. Mannitol is essential in pathogenesis to balance cell reinforcements produced by both plants and animals. Mannitol likewise serves as a source of reducing power, managing coenzymes, and controlling cytoplasmic pH by going about as a sink or hotspot for protons. The metabolic pathways for mannitol biosynthesis and catabolism have been characterized in filamentous fungi by direct diminishment of fructose-6-phosphate into mannitol-1-phosphate including a mannitol-1-phosphate phosphatase catalyst. In plants mannitol is integrated from mannose-6-phosphate to mannitol-1-phosphate, which then dephosphorylates to mannitol. The enzyme mannitol dehydrogenase plays a key role in host–pathogen interactions and must be co-localized with pathogen-secreted mannitol to resist the infection. PMID:26441941

  8. Substrate metabolism during basal and hyperinsulinemic conditions in adolescents and young-adults with Barth syndrome.

    Science.gov (United States)

    Cade, W Todd; Spencer, Carolyn T; Reeds, Dominic N; Waggoner, Alan D; O'Connor, Robert; Maisenbacher, Melissa; Crowley, Jan R; Byrne, Barry J; Peterson, Linda R

    2013-01-01

    Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by mitochondrial abnormalities, infantile or childhood onset of cardioskeletal myopathy, and high mortality rates. It is currently unknown if BTHS related mitochondrial dysfunction results in substrate metabolism abnormalities and thereby contributes to cardioskeletal myopathy in patients with BTHS. Adolescents and young adults with BTHS (n = 5, 20 ± 4 yrs) and age and activity matched healthy controls (n = 5, 18 ± 4 yrs) underwent an hyperinsulinemic-euglycemic clamp procedure with stable isotopically labeled tracers for measurement of lipolysis, fatty acid oxidation, glucose disposal, and whole-body proteolysis rates; dual energy x-ray absorptiometry for measurement of body composition and 2-D and strain echocardiography for measurement of left ventricular function. Participants with BTHS had lower fat-free mass (FFM) (BTHS: 31.4 ± 6.9 vs. 46.7 ± 5.3 kg, p trend towards higher basal leucine rate of appearance per kg FFM (BTHS: 271.4 ± 69.3 vs. 193.1 ± 28.7 μmol/kgFFM/hr, p = 0.07) compared to controls. Higher basal leucine rate of appearance per kg FFM (i.e. whole-body proteolytic rate) tended to be associated with lower left ventricular systolic strain (r = -0.57, p = 0.09). Whole-body fatty acid, glucose and amino acid metabolism kinetics when expressed per unit of body composition are altered and appear to be related to cardioskeletal myopathy in humans with BTHS. Further studies examining myocardial substrate metabolism and whole-body substrate metabolism during increased energy demands (e.g., exercise) and their relationships to skeletal and cardiac function are recommended.

  9. Mannitol metabolism during pathogenic fungal–host interactions under stressed conditions

    OpenAIRE

    Meena, Mukesh; Prasad, Vishal; Zehra, Andleeb; Gupta, Vijai K.; Upadhyay, Ram S.

    2015-01-01

    Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; furthermore, mannitol also acts as a powerful quencher of reactive oxygen species (ROS). Some phytopathogenic fungi use mannitol to stifle ROS-mediated plant resistance. Mannitol is essential in pathogenesis to balance cell reinforcements produced by both plants and animals. Mannitol likewise serves as a source of reducing power, managing coenzymes, and controlling cytoplasmic pH by going about as a...

  10. The Role of Food Peptides in Lipid Metabolism during Dyslipidemia and Associated Health Conditions

    Directory of Open Access Journals (Sweden)

    Chibuike C. Udenigwe

    2015-04-01

    Full Text Available Animal and human clinical studies have demonstrated the ability of dietary food proteins to modulate endogenous lipid levels during abnormal lipid metabolism (dyslipidemia. Considering the susceptibility of proteins to gastric proteolytic activities, the hypolipidemic functions of proteins are possibly due, in part, to their peptide fragments. Food-derived peptides may directly modulate abnormal lipid metabolism in cell cultures and animal models of dyslipidemia. The peptides are thought to act by perturbing intestinal absorption of dietary cholesterol and enterohepatic bile acid circulation, and by inhibiting lipogenic enzymatic activities and gene expression in hepatocytes and adipocytes. Recent evidence indicates that the hypolipidemic activities of some peptides are due to activation of hepatic lipogenic transcription factors. However, detailed molecular mechanisms and structural requirements of peptides for these activities are yet to be elucidated. As hypolipidemic peptides can be released during enzymatic food processing, future studies can explore the prospects of combating metabolic syndrome and associated complications using peptide-rich functional food and nutraceutical products.

  11. Metabolic Syndrome (For Parents)

    Science.gov (United States)

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

  12. RNA profiles of porcine embryos during genome activation reveal complex metabolic switch sensitive to in vitro conditions.

    Directory of Open Access Journals (Sweden)

    Olga Østrup

    Full Text Available Fertilization is followed by complex changes in cytoplasmic composition and extensive chromatin reprogramming which results in the abundant activation of totipotent embryonic genome at embryonic genome activation (EGA. While chromatin reprogramming has been widely studied in several species, only a handful of reports characterize changing transcriptome profiles and resulting metabolic changes in cleavage stage embryos. The aims of the current study were to investigate RNA profiles of in vivo developed (ivv and in vitro produced (ivt porcine embryos before (2-cell stage and after (late 4-cell stage EGA and determine major metabolic changes that regulate totipotency. The period before EGA was dominated by transcripts responsible for cell cycle regulation, mitosis, RNA translation and processing (including ribosomal machinery, protein catabolism, and chromatin remodelling. Following EGA an increase in the abundance of transcripts involved in transcription, translation, DNA metabolism, histone and chromatin modification, as well as protein catabolism was detected. The further analysis of members of overlapping GO terms revealed that despite that comparable cellular processes are taking place before and after EGA (RNA splicing, protein catabolism, different metabolic pathways are involved. This strongly suggests that a complex metabolic switch accompanies EGA. In vitro conditions significantly altered RNA profiles before EGA, and the character of these changes indicates that they originate from oocyte and are imposed either before oocyte aspiration or during in vitro maturation. IVT embryos have altered content of apoptotic factors, cell cycle regulation factors and spindle components, and transcription factors, which all may contribute to reduced developmental competence of embryos produced in vitro. Overall, our data are in good accordance with previously published, genome-wide profiling data in other species. Moreover, comparison with mouse and

  13. Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

    Science.gov (United States)

    Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

    2015-10-01

    A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Increased heme synthesis in yeast induces a metabolic switch from fermentation to respiration even under conditions of glucose repression.

    Science.gov (United States)

    Zhang, Tiantian; Bu, Pengli; Zeng, Joey; Vancura, Ales

    2017-10-13

    Regulation of mitochondrial biogenesis and respiration is a complex process that involves several signaling pathways and transcription factors as well as communication between the nuclear and mitochondrial genomes. Under aerobic conditions, the budding yeast Saccharomyces cerevisiae metabolizes glucose predominantly by glycolysis and fermentation. We have recently shown that altered chromatin structure in yeast induces respiration by a mechanism that requires transport and metabolism of pyruvate in mitochondria. However, how pyruvate controls the transcriptional responses underlying the metabolic switch from fermentation to respiration is unknown. Here, we report that this pyruvate effect involves heme. We found that heme induces transcription of HAP4, the transcriptional activation subunit of the Hap2/3/4/5p complex, required for growth on nonfermentable carbon sources, in a Hap1p- and Hap2/3/4/5p-dependent manner. Increasing cellular heme levels by inactivating ROX1, which encodes a repressor of many hypoxic genes, or by overexpressing HEM3 or HEM12 induced respiration and elevated ATP levels. Increased heme synthesis, even under conditions of glucose repression, activated Hap1p and the Hap2/3/4/5p complex and induced transcription of HAP4 and genes required for the tricarboxylic acid (TCA) cycle, electron transport chain, and oxidative phosphorylation, leading to a switch from fermentation to respiration. Conversely, inhibiting metabolic flux into the TCA cycle reduced cellular heme levels and HAP4 transcription. Together, our results indicate that the glucose-mediated repression of respiration in budding yeast is at least partly due to the low cellular heme level. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Effects of dry period length on milk production, body condition, metabolites, and hepatic glucose metabolism in dairy cows.

    Science.gov (United States)

    Weber, C; Losand, B; Tuchscherer, A; Rehbock, F; Blum, E; Yang, W; Bruckmaier, R M; Sanftleben, P; Hammon, H M

    2015-03-01

    Dry period (DP) length affects energy metabolism around calving in dairy cows as well as milk production in the subsequent lactation. The aim of the study was to investigate milk production, body condition, metabolic adaptation, and hepatic gene expression of gluconeogenic enzymes in Holstein cows (>10,000 kg milk/305 d) with 28- (n=18), 56- (n=18), and 90-d DP (n=22) length (treatment groups) in a commercial farm. Cows were fed total mixed rations ad libitum adjusted for far-off (not for 28-d DP) and close-up DP and lactation. Milk yield was recorded daily and body condition score (BCS), back fat thickness (BFT), and body weight (BW) were determined at dry off, 1 wk before expected and after calving, and on wk 2, 4, and 8 postpartum (pp). Blood samples were taken on d -56, -28, -7, 1, 7, 14, 28, and 56 relative to calving to measure plasma concentrations of metabolites and hormones. Liver biopsies (n=11 per treatment) were taken on d -10 and 10 relative to calving to determine glycogen and total liver fat concentration (LFC) and to quantify mRNA levels of pyruvate carboxylase (PC), cytosolic phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase. Time course of milk yield during first 8 wk in lactation differed among treatment. Milk protein content was higher in 28-d than in 90-d DP cows. Milk fat to protein ratio was highest and milk urea was lowest in 90-d DP cows. Differences in BW, BFT, and BCS were predominantly seen before calving with greatest BW, BFT, and BCS in 90-d DP cows. Plasma concentrations of NEFA and BHBA were elevated during the transition period in all cows, and the greatest increase pp was seen in 90-d DP cows. Plasma glucose concentration decreased around calving and was greater in 28-d than in 90-d DP cows. Dry period length also affected plasma concentrations of urea, cholesterol, aspartate transaminase, and glutamate dehydrogenase. Plasma insulin concentration decreased around calving in all cows, but insulin concentration pp was

  16. Decontamination of acid mine water from Ronneburg/Thueringen which is high in sulfates and metals using sulfate-reducing bacteria. Subproject. Final report; Mikrobiologisches Verfahren zur Reinigung radioaktiv und chemisch belasteter Waesser des Sanierungsgebietes Ronneburg. Teilprojekt: Verfahrenstechnische Untersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Glombitza, F.; Karnatz, F.; Loeffler, R.

    1998-11-27

    The authors analyzed and developed the fundamentals of a microbiological water treatment process for decontamination of acid water from a uranium mine which is high in sulfates and heavy metals. The process is based on microbiological sulfate reduction. In the pre-phase of the project, sulfate-reducing microorganisms were isolated and cultivation methods for these microorganisms developed. [German] Es wurden die verfahrestechnischen Grundlagen fuer ein mikrobiologisches Wasserbehandungsverfahren analysiert und entwickelt, mit dessen Hilfe die Wasserqualitaet von sauren, sulfat- und schwermetall- sowie radionuklidhaltigen Waessern aus dem Uranbergbau nachhaltig positiv beeinflusst werden kann. Das Verfahren basiert auf der mikrobiologischen Sulfatreduktion. In der Vorphase des Projektes wurden die dafuer geeigneten sulfatreduzierenden Mikroorganismen isoliert und geeignete Kultivierungsmethoden fuer diese Mikroorganismen entwickelt. (orig.)

  17. Exploring the Metabolic and Perceptual Correlates of Self-Selected Walking Speed under Constrained and Un-Constrained Conditions

    Directory of Open Access Journals (Sweden)

    David T Godsiff, Shelly Coe, Charlotte Elsworth-Edelsten, Johnny Collett, Ken Howells, Martyn Morris, Helen Dawes

    2018-03-01

    Full Text Available Mechanisms underpinning self-selected walking speed (SSWS are poorly understood. The present study investigated the extent to which SSWS is related to metabolism, energy cost, and/or perceptual parameters during both normal and artificially constrained walking. Fourteen participants with no pathology affecting gait were tested under standard conditions. Subjects walked on a motorized treadmill at speeds derived from their SSWS as a continuous protocol. RPE scores (CR10 and expired air to calculate energy cost (J.kg-1.m-1 and carbohydrate (CHO oxidation rate (J.kg-1.min-1 were collected during minutes 3-4 at each speed. Eight individuals were re-tested under the same conditions within one week with a hip and knee-brace to immobilize their right leg. Deflection in RPE scores (CR10 and CHO oxidation rate (J.kg-1.min-1 were not related to SSWS (five and three people had deflections in the defined range of SSWS in constrained and unconstrained conditions, respectively (p > 0.05. Constrained walking elicited a higher energy cost (J.kg-1.m-1 and slower SSWS (p 0.05. SSWS did not occur at a minimum energy cost (J.kg-1.m-1 in either condition, however, the size of the minimum energy cost to SSWS disparity was the same (Froude {Fr} = 0.09 in both conditions (p = 0.36. Perceptions of exertion can modify walking patterns and therefore SSWS and metabolism/ energy cost are not directly related. Strategies which minimize perceived exertion may enable faster walking in people with altered gait as our findings indicate they should self-optimize to the same extent under different conditions.

  18. Disrupting IGF Signaling in Adult Mice Conditions Leanness, Resilient Energy Metabolism, and High Growth Hormone Pulses.

    Science.gov (United States)

    François, Jean-Christophe; Aïd, Saba; Chaker, Zayna; Lacube, Philippe; Xu, Jie; Fayad, Racha; Côté, Francine; Even, Patrick; Holzenberger, Martin

    2017-07-01

    Growth hormone (GH) and insulinlike growth factor (IGF) promote aging and age-related pathologies. Inhibiting this pathway by targeting IGF receptor (IGF-1R) is a promising strategy to extend life span, alleviate age-related diseases, and reduce tumor growth. Although anti-IGF-1R agents are being developed, long-term effects of IGF-1R blockade remain unknown. In this study, we used ubiquitous inducible IGF-1R knockout (UBIKOR) to suppress signaling in all adult tissues and screened health extensively. Surprisingly, UBIKOR mice showed no overt defects and presented with rather inconspicuous health, including normal cognition. Endocrine GH and IGF-1 were strongly upregulated without causing acromegaly. UBIKOR mice were strikingly lean with coordinate changes in body composition and organ size. They were insulin resistant but preserved physiological energy expenditure and displayed enhanced fasting metabolic flexibility. Thus, long-term IGF-1R blockade generated beneficial effects on aging-relevant metabolism, but exposed to high GH. This needs to be considered when targeting IGF-1R to protect from neurodegeneration, retard aging, or fight cancer. Copyright © 2017 Endocrine Society.

  19. The key to acetate: metabolic fluxes of acetic acid bacteria under cocoa pulp fermentation-simulating conditions.

    Science.gov (United States)

    Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik; Wittmann, Christoph

    2014-08-01

    Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.

  20. Comment: Psoriasis Uncovered – Comorbid Conditions with Special Reference to Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Manuel Valdebran

    2014-01-01

    Full Text Available The association of psoriasis with cardiovascular disease, in particular, has been subject of research for many years, however, inconclusive results were always obtained as cardiovascular disease risk factors could act as confounders. Recently the topic have caught more attention as better designed studies have been performed thus confirming its association. Among these studies, it is very interesting to cite the meta-analysis performed by Miller et al [1] where they revised 75 relevant articles including more than 500,000 cases and found that psoriasis was associated with cardiovascular disease, ischemic heart disease, peripheral vascular disease, atherosclerosis, diabetes, hypertension, dyslipidemia, obesity by body mass index and by abdominal fat and metabolic syndrome but not associated with cerebrovascular disease and cardiovascular mortality.

  1. [Maternal nutrition during pregnancy conditions the fetal pancreas development, hormonal status and diabetes mellitus and metabolic syndrome biomarkers at birth].

    Science.gov (United States)

    Sánchez-Muniz, F J; Gesteiro, E; Espárrago Rodilla, M; Rodríguez Bernal, B; Bastida, S

    2013-01-01

    Pregnancy is a vital period where several hyperplasic, hypertrophic processes together with metabolic adaptation and preparation for extra-uterine life take place. Present review accounts for central aspects of nutrition throughout gestation on the embryonic and fetal periods. It is centered in the major changes occurring in fetal pancreas, with special mention to the susceptibility of this main glucose homeostasis organ to support nutritional changes during maturation and development. Studies performed in animal models as human are commented considering the role of maternal nutrition on β-cell mass size, insulin and other pancreatic hormones production, and insulin sensitivity. Details of both the thrifty genotype and phenotype hypothesis are given, indicating that hypo/subnutrition causes metabolic adaptations that permit the future body to grow and develop itself in limited environmental and energetic conditions. The Barker hypothesis is considered suggesting that this metabolic hypothesis is a double-edged sword in the actual abundance World. Lastly the review, taking into account our own research and other papers, analyses less known aspects that relate maternal diet with insulin resistance/sensitivity markers at delivery. Particularly the role of the saturated fatty acid/carbohydrate and omega-6/omega-3 ratios in the frame of maternal diet is reviewed considering the quality of those diets under the Healthy Eating Index and the Adherence to Mediterranean Diet scores and the relationship with insulin resistance profile at birth. Present review ends indicating that nutritional habits should be strongly stated before gestation in order to assure a proper nutrition since the first moment of pregnancy. This will support an adequate fetal and pancreatic growth and development, and in turn, adequate glucose homeostasis during pregnancy and later in life, slowing down or preventing from degenerative diseases related with metabolic syndrome and type 2 diabetes

  2. The effects of metabolic conditions on prostate cancer incidence over 15 years of follow-up: results from the Olmsted County Study

    Science.gov (United States)

    Wallner, Lauren P.; Morgenstern, Hal; McGree, Michaela E.; Jacobson, Debra J.; St. Sauver, Jennifer L.; Jacobsen, Steven J.; Sarma, Aruna V.

    2011-01-01

    OBJECTIVE To determine if combinations of obesity, hypertension and diabetes influence the development of prostate cancer over 15 years of follow-up. PATIENTS AND METHODS In 1990, a randomly selected cohort of Caucasian men from Olmsted County, MN, USA, aged 40–79 years, was recruited; 2445 completed a questionnaire that included physician-diagnosed diabetes and hypertension. Anthropometric measures were collected during clinical examination. Biopsy-confirmed prostate cancer was identified from medical records. Proportional hazards regression was used to estimate the effects of these metabolic conditions, both individually and in combination, on the incidence rate of prostate cancer. RESULTS Men with hypertension alone or in combination with diabetes were more likely to develop prostate cancer than were men without any of the metabolic conditions. The metabolic syndrome – the presence of all three conditions compared with men with no metabolic components – was only minimally and inversely associated with prostate cancer [hazard ratio (HR): 0.81; 95% confidence interval (CI): 0.20, 3.3] and no monotonic association between the number of metabolic components and prostate cancer was observed. CONCLUSIONS Our results suggest that it may not be sufficient to treat metabolic conditions as one variable when investigating the aetiology of prostate cancer in Caucasian men. Further research should focus on the separate and combined effects of these metabolic conditions in large samples. PMID:20880183

  3. Hepatically-metabolized and -excreted artificial oxygen carrier, hemoglobin vesicles, can be safely used under conditions of hepatic impairment.

    Science.gov (United States)

    Taguchi, Kazuaki; Miyasato, Mayumi; Ujihira, Hayato; Watanabe, Hiroshi; Kadowaki, Daisuke; Sakai, Hiromi; Tsuchida, Eishun; Horinouchi, Hirohisa; Kobayashi, Koichi; Maruyama, Toru; Otagiri, Masaki

    2010-11-01

    The hemoglobin vesicle (HbV) is an artificial oxygen carrier in which a concentrated Hb solution is encapsulated in lipid vesicles. Our previous studies demonstrated that HbV is metabolized by the mononuclear phagocyte system, and the lipid components are excreted from the liver. It is well-known that many hepatically-metabolized and -excreted drugs show altered pharmaceutics under conditions of liver impairment, which results in adverse effects. The aim of this study was to determine whether the administration of HbV causes toxicity in rats with carbon tetrachloride induced liver cirrhosis. Changes in plasma biochemical parameters, histological staining and the pharmacokinetic distribution of HbV were evaluated after an HbV injection of the above model rats at a putative clinical dose (1400 mgHb/kg). Plasma biochemical parameters were not significantly affected, except for a transient elevation of lipase, lipid components and bilirubin, which recovered within 14 days after an HbV infusion. Negligible morphological changes were observed in the kidney, liver, spleen, lung and heart. Hemosiderin, a marker of iron accumulation in organs, was observed in the liver and spleen up to 14 days after HbV treatment, but no evidence of oxidative stress in the plasma and liver were observed. HbV is mainly distributed in the liver and spleen, and the lipid components are excreted into feces within 7 days. In conclusion, even under conditions of hepatic cirrhosis, HbV and its components exhibit the favorable metabolic and excretion profile at the putative clinical dose. These findings provide further support for the safety and effectiveness of HbV in clinical settings. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

  4. Associations among serum pro- and anti-inflammatory cytokines, metabolic mediators, body condition, and uterine disease in postpartum dairy cows

    Science.gov (United States)

    2013-01-01

    Background Adipose tissue is an active endocrine organ which secretes a wide range of hormones and protein factors, collectively termed adipokines. Adipokines affect appetite and satiety, glucose and lipid metabolism, inflammation and immune functions. The objectives were to evaluate serum concentrations of adipokines (adiponectin, leptin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6) in lactating dairy cows with postpartum uterine inflammatory conditions (metritis, clinical endometritis or subclinical endometritis) and in cows experiencing loss of body condition, and to assess the relationship of adipokines and body condition loss in the establishment of persistent uterine inflammatory conditions. Methods Lactating multiparous Holstein cows (N = 40), with body condition scores (BCS) from 2 to 4 (eight cows for each 0.5 score increment) were enrolled. Body condition was monitored for all cows weekly for 7 weeks post calving; cows with uterine inflammatory conditions were also re-evaluated 2 weeks later. Blood samples were collected from 1 week prior to calving to 7 weeks after calving for determination of serum concentrations of adipokines, insulin and insulin like growth factor (IGF)-1. Results Cows with metritis or clinical endometritis had higher serum concentrations of adiponectin, leptin, TNF-alpha, IL-1beta and IL-6 compared to normal cows (P cows with subclinical endometritis compared to normal cows (P cows with metritis or clinical endometritis. Cows with low BCS (2 and 2.5) had significantly higher adiponectin, TNF-alpha, IL-1beta and IL-6 than those with high BCS (3 to 4). Cows with persistent uterine inflammatory conditions had higher adiponectin, leptin TNF-alpha, IL-1beta and IL-6 and insulin compared to normal and spontaneously recovered cows, except for IGF-1 (P cows. PMID:24209779

  5. The succinate receptor as a novel therapeutic target for oxidative and metabolic stress-related conditions.

    Directory of Open Access Journals (Sweden)

    Ana Carolina eAriza

    2012-02-01

    Full Text Available The succinate receptor (also known as GPR91 is a G protein-coupled receptor that is closely related to the family of P2Y purinoreceptors. It is expressed in a variety of tissues, including blood cells, adipose tissue, the liver, retina and kidney. In these tissues, this receptor and its ligand succinate have recently emerged as novel mediators in local stress situations, including ischemia, hypoxia, toxicity and hyperglycemia. Amongst others, the succinate receptor is involved in recruitment of immune cells to transplanted tissues. Moreover, it was shown to play a key role in the development of diabetic retinopathy. However, most prominently, the role of locally increased succinate levels and succinate receptor activation in the kidney, stimulating the systemic and local renin-angiotensin system, starts to unfold: The succinate receptor is a key mediator in the development of hypertension and possibly fibrosis in diabetes mellitus and metabolic syndrome. This makes the succinate receptor a promising drug target to counteract or prevent cardiovascular and fibrotic defects in these expanding disorders. Recent development of SUCNR1-specific antagonists opens novel possibilities for research in models for these disorders and may eventually provide novel opportunities for the treatment of patients.

  6. Significant Association between Sulfate-Reducing Bacteria and Uranium-Reducing Microbial Communities as Revealed by a Combined Massively Parallel Sequencing-Indicator Species Approach▿ †

    Science.gov (United States)

    Cardenas, Erick; Wu, Wei-Min; Leigh, Mary Beth; Carley, Jack; Carroll, Sue; Gentry, Terry; Luo, Jian; Watson, David; Gu, Baohua; Ginder-Vogel, Matthew; Kitanidis, Peter K.; Jardine, Philip M.; Zhou, Jizhong; Criddle, Craig S.; Marsh, Terence L.; Tiedje, James M.

    2010-01-01

    Massively parallel sequencing has provided a more affordable and high-throughput method to study microbial communities, although it has mostly been used in an exploratory fashion. We combined pyrosequencing with a strict indicator species statistical analysis to test if bacteria specifically responded to ethanol injection that successfully promoted dissimilatory uranium(VI) reduction in the subsurface of a uranium contamination plume at the Oak Ridge Field Research Center in Tennessee. Remediation was achieved with a hydraulic flow control consisting of an inner loop, where ethanol was injected, and an outer loop for flow-field protection. This strategy reduced uranium concentrations in groundwater to levels below 0.126 μM and created geochemical gradients in electron donors from the inner-loop injection well toward the outer loop and downgradient flow path. Our analysis with 15 sediment samples from the entire test area found significant indicator species that showed a high degree of adaptation to the three different hydrochemical-created conditions. Castellaniella and Rhodanobacter characterized areas with low pH, heavy metals, and low bioactivity, while sulfate-, Fe(III)-, and U(VI)-reducing bacteria (Desulfovibrio, Anaeromyxobacter, and Desulfosporosinus) were indicators of areas where U(VI) reduction occurred. The abundance of these bacteria, as well as the Fe(III) and U(VI) reducer Geobacter, correlated with the hydraulic connectivity to the substrate injection site, suggesting that the selected populations were a direct response to electron donor addition by the groundwater flow path. A false-discovery-rate approach was implemented to discard false-positive results by chance, given the large amount of data compared. PMID:20729318

  7. Designing and implementing a longitudinal study of children with neurological, genetic or metabolic conditions: charting the territory

    Directory of Open Access Journals (Sweden)

    Davies Betty

    2010-09-01

    Full Text Available Abstract Background Children with progressive metabolic, neurological, or chromosomal conditions and their families anticipate an unknown lifespan, endure unstable and often painful symptoms, and cope with erratic emotional and spiritual crises as the condition progresses along an uncertain trajectory towards death. Much is known about the genetics and pathophysiology of these diseases, but very little has been documented about the trajectory of symptoms for children with these conditions or the associated experience of their families. A longitudinal study design will help to close this gap in knowledge. Methods/Design Charting the Territory is a longitudinal descriptive, correlational study currently underway with children 0-19 years who are diagnosed with progressive neurological, metabolic, or chromosomal conditions and their families. The purpose of the study is to determine and document the clinical progression of the condition and the associated bio-psychosocial-spiritual experiences of the parents and siblings age 7-18 years. Approximately 300 families, both newly diagnosed children and those with established conditions, are being recruited in six Canadian cities. Children and their families are being followed for a minimum of 18 months, depending on when they enroll in the study. Family data collection will continue after the child's death if the child dies during the study period. Data collection includes monthly parental assessment of the child's symptoms; an annual functional assessment of the child; and completion of established instruments every 6 months by parents to assess family functioning, marital satisfaction, health status, anxiety, depression, stress, burden, grief, spirituality, and growth, and by siblings to assess coping and health. Impact of participation on parents is assessed after 1 year and at the end of the study. Chart reviews are conducted at enrollment and at the conclusion of the study or at the time of the

  8. Effects of stevia on synaptic plasticity and NADPH oxidase level of CNS in conditions of metabolic disorders caused by fructose.

    Science.gov (United States)

    Chavushyan, V A; Simonyan, K V; Simonyan, R M; Isoyan, A S; Simonyan, G M; Babakhanyan, M A; Hovhannisyian, L E; Nahapetyan, Kh H; Avetisyan, L G; Simonyan, M A

    2017-12-19

    Excess dietary fructose intake associated with metabolic syndrome and insulin resistance and increased risk of developing type 2 diabetes. Previous animal studies have reported that diabetic animals have significantly impaired behavioural and cognitive functions, pathological synaptic function and impaired expression of glutamate receptors. Correction of the antioxidant status of laboratory rodents largely prevents the development of fructose-induced plurimetabolic changes in the nervous system. We suggest a novel concept of efficiency of Stevia leaves for treatment of central diabetic neuropathy. By in vivo extracellular studies induced spike activity of hippocampal neurons during high frequency stimulation of entorhinal cortex, as well as neurons of basolateral amygdala to high-frequency stimulation of the hippocampus effects of Stevia rebaudiana Bertoni plant evaluated in synaptic activity in the brain of fructose-enriched diet rats. In the conditions of metabolic disorders caused by fructose, antioxidant activity of Stevia rebaudiana was assessed by measuring the NOX activity of the hippocampus, amygdala and spinal cord. In this study, the characteristic features of the metabolic effects of dietary fructose on synaptic plasticity in hippocampal neurons and basolateral amygdala and the state of the NADPH oxidase (NOX) oxidative system of these brain formations are revealed, as well as the prospects for development of multitarget and polyfunctional phytopreparations (with adaptogenic, antioxidant, antidiabetic, nootropic activity) from native raw material of Stevia rebaudiana. Stevia modulates degree of expressiveness of potentiation/depression (approaches but fails to achieve the norm) by shifting the percentage balance in favor of depressor type of responses during high-frequency stimulation, indicating its adaptogenic role in plasticity of neural networks. Under the action of fructose an increase (3-5 times) in specific quantity of total fraction of NOX

  9. Carotenoid metabolism during bilberry (Vaccinium myrtillus L.) fruit development under different light conditions is regulated by biosynthesis and degradation.

    Science.gov (United States)

    Karppinen, Katja; Zoratti, Laura; Sarala, Marian; Carvalho, Elisabete; Hirsimäki, Jenni; Mentula, Helmi; Martens, Stefan; Häggman, Hely; Jaakola, Laura

    2016-04-21

    Carotenoids are important pigments and precursors for central signaling molecules associated in fruit development and ripening. Carotenoid metabolism has been studied especially in the climacteric tomato fruit but the content of carotenoids and the regulation of their metabolism have been shown to be highly variable between fruit species. Non-climacteric berries of the genus Vaccinium are among the best natural sources of health-beneficial flavonoids but not studied previously for carotenoid biosynthesis. In this study, carotenoid biosynthetic genes, PSY, PDS, ZDS, CRTISO, LCYB, LCYE, BCH and CYP450-BCH, as well as a carotenoid cleavage dioxygenase CCD1 were identified from bilberry (V. myrtillus L.) fruit and their expression was studied along with carotenoid composition during fruit development under different photoperiod and light quality conditions. Bilberry was found to be a good source of carotenoids among fruits and berries. The most abundant carotenoids throughout the berry development were lutein and β-carotene, which were accompanied by lower amounts of 9Z-β-carotene, violaxanthin, neoxanthin, zeaxanthin, antheraxanthin and β-cryptoxanthin. The expression patterns of the biosynthetic genes in ripening fruits indicated a metabolic flux towards β-branch of the carotenoid pathway. However, the carotenoid levels decreased in both the β-branch and ε,β-branch towards bilberry fruit ripening along with increased VmCCD1 expression, similarly to VmNCED1, indicating enzymatic carotenoid cleavage and degradation. Intense white light conditions increased the expression of the carotenoid biosynthetic genes but also the expression of the cleavage genes VmCCD1 and VmNCED1, especially in unripe fruits. Instead, mature bilberry fruits responded specifically to red/far-red light wavelengths by inducing the expression of both the carotenoid biosynthetic and the cleavage genes indicating tissue and developmental stage specific regulation of apocarotenoid formation by

  10. Normobaric hypoxic conditioning to maximize weight loss and ameliorate cardio-metabolic health in obese populations: a systematic review.

    Science.gov (United States)

    Hobbins, L; Hunter, S; Gaoua, N; Girard, O

    2017-09-01

    Normobaric hypoxic conditioning (HC) is defined as exposure to systemic and/or local hypoxia at rest (passive) or combined with exercise training (active). HC has been previously used by healthy and athletic populations to enhance their physical capacity and improve performance in the lead up to competition. Recently, HC has also been applied acutely (single exposure) and chronically (repeated exposure over several weeks) to overweight and obese populations with the intention of managing and potentially increasing cardio-metabolic health and weight loss. At present, it is unclear what the cardio-metabolic health and weight loss responses of obese populations are in response to passive and active HC. Exploration of potential benefits of exposure to both passive and active HC may provide pivotal findings for improving health and well being in these individuals. A systematic literature search for articles published between 2000 and 2017 was carried out. Studies investigating the effects of normobaric HC as a novel therapeutic approach to elicit improvements in the cardio-metabolic health and weight loss of obese populations were included. Studies investigated passive ( n = 7; 5 animals, 2 humans), active ( n = 4; all humans) and a combination of passive and active ( n = 4; 3 animals, 1 human) HC to an inspired oxygen fraction ([Formula: see text]) between 4.8 and 15.0%, ranging between a single session and daily sessions per week, lasting from 5 days up to 8 mo. Passive HC led to reduced insulin concentrations (-37 to -22%) in obese animals and increased energy expenditure (+12 to +16%) in obese humans, whereas active HC lead to reductions in body weight (-4 to -2%) in obese animals and humans, and blood pressure (-8 to -3%) in obese humans compared with a matched workload in normoxic conditions. Inconclusive findings, however, exist in determining the impact of acute and chronic HC on markers such as triglycerides, cholesterol levels, and fitness capacity

  11. Features of selenium metabolism in humans living under the conditions of North European Russia.

    Science.gov (United States)

    Parshukova, Olga; Potolitsyna, Natalya; Shadrina, Vera; Chernykh, Aleksei; Bojko, Evgeny

    2014-08-01

    Selenium supplementation and its effects on Northerners have been little studied. The aim of our study was to assess the selenium levels of the inhabitants of North European Russia, the seasonal aspects of selenium supplementation, and the interrelationships between selenium levels and the levels of thyroid gland hormones. To study the particular features of selenium metabolism in Northerners over the course of 1 year, 19 healthy male Caucasian volunteers (18-21 years old) were recruited for the present study. The subjects were military guards in a Northern European region of Russia (Syktyvkar, Russia, 62°N latitude) who spent 6-10-h outdoors daily. The study was conducted over a 12-month period. Selenium levels, glutathione peroxidase (GP) activity, as well as total triiodothyronine (T3), total thyroxin (T4), free thyroxin, free triiodothyronine, and thyrotropin (TSH) levels, were determined in the blood serum. The study subjects showed low levels of plasma selenium throughout the year. We observed a noticeable decrease in plasma selenium levels during the period from May to August, with the lowest levels in July. Selenium levels in the military guards correlated with the levels of selenium-dependent GP enzyme activity throughout the year. Additionally, we demonstrated a significant correlation between selenium and pituitary-thyroid axis hormones (total T3, free T4, and TSH) in periods in which plasma selenium levels were lower than the established normal ranges. Over the course of 1 year, low levels of plasma selenium affect GP activity and thyroid hormone levels in humans living in North European Russia.

  12. Pyruvate and lactate metabolism by Shewanella oneidensis MR-1 under fermentation, oxygen limitation, and fumarate respiration conditions.

    Science.gov (United States)

    Pinchuk, Grigoriy E; Geydebrekht, Oleg V; Hill, Eric A; Reed, Jennifer L; Konopka, Allan E; Beliaev, Alexander S; Fredrickson, Jim K

    2011-12-01

    Shewanella oneidensis MR-1 is a facultative anaerobe that derives energy by coupling organic matter oxidation to the reduction of a wide range of electron acceptors. Here, we quantitatively assessed the lactate and pyruvate metabolism of MR-1 under three distinct conditions: electron acceptor-limited growth on lactate with O(2), lactate with fumarate, and pyruvate fermentation. The latter does not support growth but provides energy for cell survival. Using physiological and genetic approaches combined with flux balance analysis, we showed that the proportion of ATP produced by substrate-level phosphorylation varied from 33% to 72.5% of that needed for growth depending on the electron acceptor nature and availability. While being indispensable for growth, the respiration of fumarate does not contribute significantly to ATP generation and likely serves to remove formate, a product of pyruvate formate-lyase-catalyzed pyruvate disproportionation. Under both tested respiratory conditions, S. oneidensis MR-1 carried out incomplete substrate oxidation, whereby the tricarboxylic acid (TCA) cycle did not contribute significantly. Pyruvate dehydrogenase was not involved in lactate metabolism under conditions of O(2) limitation but was required for anaerobic growth, likely by supplying reducing equivalents for biosynthesis. The results suggest that pyruvate fermentation by S. oneidensis MR-1 cells represents a combination of substrate-level phosphorylation and respiration, where pyruvate serves as an electron donor and an electron acceptor. Pyruvate reduction to lactate at the expense of formate oxidation is catalyzed by a recently described new type of oxidative NAD(P)H-independent d-lactate dehydrogenase (Dld-II). The results further indicate that pyruvate reduction coupled to formate oxidation may be accompanied by the generation of proton motive force.

  13. Metabolic Syndrome

    Science.gov (United States)

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

  14. Regulatory and metabolic networks for the adaptation of Pseudomonas aeruginosa biofilms to urinary tract-like conditions.

    Directory of Open Access Journals (Sweden)

    Petra Tielen

    Full Text Available Biofilms of the Gram-negative bacterium Pseudomonas aeruginosa are one of the major causes of complicated urinary tract infections with detrimental outcome. To develop novel therapeutic strategies the molecular adaption strategies of P. aeruginosa biofilms to the conditions of the urinary tract were investigated thoroughly at the systems level using transcriptome, proteome, metabolome and enzyme activity analyses. For this purpose biofilms were grown anaerobically in artificial urine medium (AUM. Obtained data were integrated bioinformatically into gene regulatory and metabolic networks. The dominating response at the transcriptome and proteome level was the adaptation to iron limitation via the broad Fur regulon including 19 sigma factors and up to 80 regulated target genes or operons. In agreement, reduction of the iron cofactor-dependent nitrate respiratory metabolism was detected. An adaptation of the central metabolism to lactate, citrate and amino acid as carbon sources with the induction of the glyoxylate bypass was observed, while other components of AUM like urea and creatinine were not used. Amino acid utilization pathways were found induced, while fatty acid biosynthesis was reduced. The high amounts of phosphate found in AUM explain the reduction of phosphate assimilation systems. Increased quorum sensing activity with the parallel reduction of chemotaxis and flagellum assembly underscored the importance of the biofilm life style. However, reduced formation of the extracellular polysaccharide alginate, typical for P. aeruginosa biofilms in lungs, indicated a different biofilm type for urinary tract infections. Furthermore, the obtained quorum sensing response results in an increased production of virulence factors like the extracellular lipase LipA and protease LasB and AprA explaining the harmful cause of these infections.

  15. Regulatory and Metabolic Networks for the Adaptation of Pseudomonas aeruginosa Biofilms to Urinary Tract-Like Conditions

    Science.gov (United States)

    Dohnt, Katrin; Haddad, Isam; Jänsch, Lothar; Klein, Johannes; Narten, Maike; Pommerenke, Claudia; Scheer, Maurice; Schobert, Max; Schomburg, Dietmar; Thielen, Bernhard; Jahn, Dieter

    2013-01-01

    Biofilms of the Gram-negative bacterium Pseudomonas aeruginosa are one of the major causes of complicated urinary tract infections with detrimental outcome. To develop novel therapeutic strategies the molecular adaption strategies of P. aeruginosa biofilms to the conditions of the urinary tract were investigated thoroughly at the systems level using transcriptome, proteome, metabolome and enzyme activity analyses. For this purpose biofilms were grown anaerobically in artificial urine medium (AUM). Obtained data were integrated bioinformatically into gene regulatory and metabolic networks. The dominating response at the transcriptome and proteome level was the adaptation to iron limitation via the broad Fur regulon including 19 sigma factors and up to 80 regulated target genes or operons. In agreement, reduction of the iron cofactor-dependent nitrate respiratory metabolism was detected. An adaptation of the central metabolism to lactate, citrate and amino acid as carbon sources with the induction of the glyoxylate bypass was observed, while other components of AUM like urea and creatinine were not used. Amino acid utilization pathways were found induced, while fatty acid biosynthesis was reduced. The high amounts of phosphate found in AUM explain the reduction of phosphate assimilation systems. Increased quorum sensing activity with the parallel reduction of chemotaxis and flagellum assembly underscored the importance of the biofilm life style. However, reduced formation of the extracellular polysaccharide alginate, typical for P. aeruginosa biofilms in lungs, indicated a different biofilm type for urinary tract infections. Furthermore, the obtained quorum sensing response results in an increased production of virulence factors like the extracellular lipase LipA and protease LasB and AprA explaining the harmful cause of these infections. PMID:23967252

  16. Metabolism of xenobiotics by Chlamydomonas reinhardtii: Phenol degradation under conditions affecting photosynthesis.

    Science.gov (United States)

    Nazos, Theocharis T; Kokarakis, Emmanouel J; Ghanotakis, Demetrios F

    2017-01-01

    In the present work, the biodegradation of phenol by axenic cultures of the unicellular microalga Chlamydomonas reinhardtii was investigated. Biodegradation proved to be a dynamic bioenergetic process, affected by changes in the culture conditions. Microalgae biodegraded defined amounts of phenol, as a result of the induced stress caused at high concentrations, despite the fact that this process proved to be energy demanding and thus affected growth of the culture. High levels of biodegradation were observed both in the absence of an alternative carbon source and in the presence of acetate as a carbon source. Biodegradation of phenol by Chlamydomonas proved to be an aerobic, photoregulated process. This is the first time that Chlamydomonas reinhardtii has been used for bioremediation purposes. This study has demonstrated that the most important factor in the biodegradation of phenol is the selection of the appropriate culture conditions (presence or absence of alternative carbon source, light intensity, and oxygen availability) that provide the best bioenergetic balance among growth, induced stress, and biodegradation of phenol.

  17. Comprehensive proteomics of Methylobacterium extorquens AM1 metabolism under single carbon and non-methylotrophic conditions

    Science.gov (United States)

    Bosch, Gundula; Skovran, Elizabeth; Xia, Qiangwei; Wang, Tiansong; Taub, Fred; Miller, Jonathan A.; Lidstrom, Mary E.; Hackett, Murray

    2009-01-01

    In order to validate a gel free quantitative proteomics assay for the model methylotrophic bacterium Methylobacterium extorquens AM1, we examined the M. extorquens AM1 proteome under single carbon (methanol) and multi-carbon (succinate) growth, conditions that have been studied for decades and for which extensive corroborative data have been compiled. In total, 4,447 proteins from a database containing 7,556 putative ORFs from M. extorquens AM1 could be identified with two or more peptide sequences, corresponding to a qualitative proteome coverage of 58%. Statistically significant non-zero (log2 scale) differential abundance ratios of methanol/succinate could be detected for 317 proteins using summed ion intensity measurements and 585 proteins using spectral counting, at a q-value cut-off of 0.01, a measure of false discovery rate. The results were compared to recent microarray studies performed under equivalent chemostat conditions. The M. extorquens AM1 studies demonstrated the feasibility of scaling up the multidimensional capillary HPLC tandem mass spectrometry approach to a prokaryotic organism with a proteome more than three times the size of microbes we have investigated previously, while maintaining a high degree of proteome coverage and reliable quantitative abundance ratios. PMID:18686303

  18. Metabolic regulation during constant moderate physical exertion in extreme conditions in Type 1 diabetes.

    Science.gov (United States)

    Valletta, J J; Chipperfield, A J; Clough, G F; Byrne, C D

    2012-06-01

    Constant moderate intensity physical exertion in humid environments at altitude poses a considerable challenge to maintaining euglycaemia with Type 1 diabetes. Blood glucose concentrations and energy expenditure were continuously recorded in a person trekking at altitude in a tropical climate to quantify changes in glucose concentrations in relation to energy expenditure. Blood glucose concentrations and energy expenditure were continuously monitored with a Guardian® real-time continuous glucose monitoring system (CGMS) and a SenseWear® Pro3 armband (BodyMedia Inc., USA), in a 27-year-old woman with Type 1 diabetes, during her climb up Mount Kinabalu in Borneo (c. 4095 m). Comparative control data from the same person was collected in the UK (temperate climate at sea level) and Singapore (tropical climate at sea level). Maximum physical effort during the climb was < 60% VO(2MAX) (maximal oxygen consumption). Mean daily calorific intakes were 2300 kcal (UK), 2370 kcal (Singapore) and 2274 kcal (Mount Kinabalu), and mean daily insulin doses were 54 U (UK), 40 U (Singapore) and 47 U (Mount Kinabalu). Despite markedly increased energy expenditure during the climb [4202 kcal (Mount Kinabalu) vs. 2948 kcal (UK) and 2662 kcal (Singapore)], mean blood glucose was considerably higher during the trek up Mount Kinabalu [13.2 ± 5.9 mmol/l, vs. 7.9 ± 3.8 mmol/l (UK) and 8.6 ± 4.0 mmol/l (Singapore)]. Marked unexpected hyperglycaemia occurred while trekking on Mount Kinabalu, despite similar calorie consumption and insulin doses to control conditions. Because of the risk of unexpected hyperglycaemia in these conditions, we recommend that patients embarking on similar activity holidays undertake frequent blood glucose monitoring. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

  19. Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions

    DEFF Research Database (Denmark)

    Gregersen, N.T.; Bitz, C.; Krog-Mikkelsen, I.

    2009-01-01

    Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE......) and fat oxidation over a single day. Fifteen healthy, normal-weight males received capsules containing placebo, caffeine alone (150mg), or caffeine plus a catechin mixture (600 mg) enriched in either epigallocatechin-3-gallate (EGCG), epigallocatechin or a mix of catechins, in a randomised cross......-over double-blinded design. On each test day EE, respiratory quotient (RQ) and substrate oxidation were measured under sedentary conditions in a respiratory chamber for 13.5h. We found no significant treatment effect on EE (P=0.20) or RQ (P=0.68). EGCG with caffeine insignificantly raised EE and fat oxidation...

  20. Optimizing conditions of polysaccharide extraction from Shiitake mushroom using response surface methodology and its regulating lipid metabolism.

    Science.gov (United States)

    Zhu, Min; Nie, Ping; Liang, Yongkang; Wang, Bing

    2013-06-20

    Process conditions (extraction time, extraction temperature, water/solid ratio and incubation time) of Shiitake mushroom polysaccharides (SMP) were optimized by conducting experiments at three different levels using the response surface method (RSM). A second-order polynomial response surface equation was developed indicating the effect of variables on polysaccharides yield. Contour maps generated using the response surface equation showed that all the experimental variables significantly affected the yield. The effect of SMP on oxidative damage in mice fed by high cholesterol diet (HCD) was done in vivo. Results showed that SMP can decreased serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-c) levels, and increased high density lipoprotein (HDL-c) levels in HCD mice. Treatment with SMP reduced blood, liver lipid peroxidation level and increased antioxidant enzymes activities. Thus it can be concluded that SMP can improve lipid metabolism and decreased oxidative damage in HCD mice. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Weight, body condition, milk production, and metabolism of Nellore cows when their calves are submitted to different supplementation levels.

    Science.gov (United States)

    Gomes da Silva, Aline; Paulino, Mário Fonseca; da Silva Amorim, Lincoln; Detmann, Edenio; Rennó, Luciana Navajas; de Souza Duarte, Márcio; Henrique de Moura, Felipe; Prímola de Melo, Luciano; Henrique Silva E Paiva, Paulo; Manso, Marcos Rocha; Valério de Carvalho, Victor

    2017-02-01

    Creep feeding has been used to reduce calves' nutritional dependence on the cow, but research results under tropical conditions have not been conclusive about the effects on the cow. Therefore, this study was conducted to evaluate the effects of high and low supplementation levels for Nellore heifer calves on performance, milk production, and metabolic profile of their mothers. Fifty multiparous Nellore cows and their respective calves were used. The following treatments were evaluated: 0-control, no supplement was fed to calves; 3-calves received supplement in the amount of 3 g/kg of body weight (BW); 6-calves received supplement in the amount of 6 g/kg of BW. There was no significant effect of level of supplementation offered to offspring on cow BW, body condition score (BCS) and subcutaneous fat thickness (P > 0.05). Level of supplementation of heifer calves did not significantly affect milk production corrected to 4% of fat (P > 0.05). Fat, protein, lactose, and total solids of the milk also did not differ among supplementation strategies (P > 0.05). Level of supplement fed to calves had no effect on cows' glucose, total cholesterol, HDL, LDL, triglycerides, total protein, and albumin levels (P > 0.05), but cows nursing calves that did not receive supplement had lower level of serum urea N (SUN; P < 0.05). We conclude that creep feeding in the amounts of 3 or 6 g/kg of BW daily has no major impact on dams' performance and metabolism.

  2. Effects of ocean acidification and hydrodynamic conditions on carbon metabolism and dissolved organic carbon (DOC fluxes in seagrass populations.

    Directory of Open Access Journals (Sweden)

    Luis G Egea

    Full Text Available Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important

  3. Effects of ocean acidification and hydrodynamic conditions on carbon metabolism and dissolved organic carbon (DOC) fluxes in seagrass populations.

    Science.gov (United States)

    Egea, Luis G; Jiménez-Ramos, Rocío; Hernández, Ignacio; Bouma, Tjeerd J; Brun, Fernando G

    2018-01-01

    Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA) and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC) in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important implications for the

  4. Sulfate-reducing bacteria in human periodontitis

    NARCIS (Netherlands)

    Langendijk Genevaux, P.S.

    2001-01-01

    Periodontitis is the major cause of the loss of teeth among adults. A mixture of bacteria then settles under the gingiva, and is implicated in the degradation of tooth-supporting tissue. In the deepening lesion, or pocket, the adjacent bone is degraded too, which will eventually lead to the loss of

  5. Thermophilic methanol utilization by sulfate reducing bacteria

    NARCIS (Netherlands)

    Goorissen, Helene Petronel

    2002-01-01

    The deposition of sulfuroxyaninons like sulfate, sulfite, and thiosulfate by man causes severe environmental problems like anaerobiosis of surface water and acid rain. The classical way of treatment of sulfuroxyanions containing waste streams like flue- gases is a chemical process in which the

  6. Sulfate-reducing bacteria in anaerobic bioreactors

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the

  7. Decolorization of reactive azo dyes by Cunninghamella elegans UCP 542 under co-metabolic conditions.

    Science.gov (United States)

    Ambrósio, S T; Campos-Takaki, G M

    2004-01-01

    The inappropriate disposal of dyes in wastewater constitutes an environmental problem and can cause damage to the ecosystem. Alternative treatments have been reported that fungi are particularly effective in the decolorization of textile effluents. The decolorization of dyes with different molecular structures by Cunninghamella elegans was evaluated under several media conditions. The decolorization procedures consisted of adding 72 h of mycelium into the culture medium containing either orange or reactive black or reactive red or a mixture of these dyes in the presence or absence of sucrose and/or peptone. The decolorization profile was highly dependent upon the incubation time, the molecular structure of the dye and presence or absence of co-substrates. The presence of sucrose or both sucrose and peptone significantly increased the decolorization of the solutions, however, the presence of only the nitrogen source suppressed it. The ultraviolet spectra of the solutions before and after decolorization suggested the occurrence of biodegradation in addition to the biosorption of the dyes. All tested dyes, except for the reactive black, caused inhibition of respiration of Escherichia coli, which suggested that toxic metabolites were produced.

  8. Metabolic engineering of Saccharomyces cerevisiae for production of spermidine under optimal culture conditions.

    Science.gov (United States)

    Kim, Sun-Ki; Jo, Jung-Hyun; Park, Yong-Cheol; Jin, Yong-Su; Seo, Jin-Ho

    2017-06-01

    Spermidine is a polyamine compound exhibiting important biological activities, such as increasing lifespan, inflammation reduction, and plant growth control. As such, many applications of spermidine as a bio-modulating agent are anticipated. However, sustainable and scalable production of spermidine has not been achieved yet. Therefore, construction of a spermidine production system using Saccharomyces cerevisiae was attempted in this study. In order to secrete spermidine into fermentation broth, TPO1 coding for the polyamine transporter was overexpressed in an engineered S. cerevisiae strain capable of accumulating high concentrations of spermidine. Through optimization of fermentation conditions, the resulting strain (OS123/pTPO1) produced 63.6mg/l spermidine with a yield of 1.3mg spermidine/g glucose. However, we observed that spermidine production was repressed in the presence of glucose. To circumvent this problem, the genetic modifications for overproducing spermidine were introduced into an engineered S. cerevisiae capable of fermenting xylose. In a fed-batch fermentation using a mixture of glucose and xylose, the resulting strain (SR8 OS123/pTPO1) produced 224mg/l spermidine with a yield of 2.2mg spermidine/g sugars. These results suggest that engineered yeast constructed in this study can be employed for the production of spermidine. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Application of Pseudomonas fluorescens to Blackberry under Field Conditions Improves Fruit Quality by Modifying Flavonoid Metabolism.

    Directory of Open Access Journals (Sweden)

    Daniel Garcia-Seco

    Full Text Available Application of a plant growth promoting rhizobacterium (PGPR, Pseudomonas fluorescens N21.4, to roots of blackberries (Rubus sp. is part of an optimised cultivation practice to improve yields and quality of fruit throughout the year in this important fruit crop. Blackberries are especially rich in flavonoids and therefore offer potential benefits for human health in prevention or amelioration of chronic diseases. However, the phenylpropanoid pathway and its regulation during ripening have not been studied in detail, in this species. PGPR may trigger flavonoid biosynthesis as part of an induced systemic response (ISR given the important role of this pathway in plant defence, to cause increased levels of flavonoids in the fruit. We have identified structural genes encoding enzymes of the phenylpropanoid and flavonoid biosynthetic pathways catalysing the conversion of phenylalanine to the final products including flavonols, anthocyanins and catechins from blackberry, and regulatory genes likely involved in controlling the activity of pathway branches. We have also measured the major flavonols, anthocyanins and catechins at three stages during ripening. Our results demonstrate the coordinated expression of flavonoid biosynthetic genes with the accumulation of anthocyanins, catechins, and flavonols in developing fruits of blackberry. Elicitation of blackberry plants by treatment of roots with P.fluorescens N21.4, caused increased expression of some flavonoid biosynthetic genes and an accompanying increase in the concentration of selected flavonoids in fruits. Our data demonstrate the physiological mechanisms involved in the improvement of fruit quality by PGPR under field conditions, and highlight some of the genetic targets of elicitation by beneficial bacteria.

  10. Metabolic analysis of antibody producing Chinese hamster ovary cell culture under different stresses conditions.

    Science.gov (United States)

    Badsha, Md Bahadur; Kurata, Hiroyuki; Onitsuka, Masayoshi; Oga, Takushi; Omasa, Takeshi

    2016-07-01

    Chinese hamster ovary (CHO) cells are commonly used as the host cell lines concerning their ability to produce therapeutic proteins with complex post-translational modifications. In this study, we have investigated the time course extra- and intracellular metabolome data of the CHO-K1 cell line, under a control and stress conditions. The addition of NaCl and trehalose greatly suppressed cell growth, where the maximum viable cell density of NaCl and trehalose cultures were 2.2-fold and 2.8-fold less than that of a control culture. Contrariwise, the antibody production of both the NaCl and trehalose cultures was sustained for a longer time to surpass that of the control culture. The NaCl and trehalose cultures showed relatively similar dynamics of cell growth, antibody production, and substrate/product concentrations, while they indicated different dynamics from the control culture. The principal component analysis of extra- and intracellular metabolome dynamics indicated that their dynamic behaviors were consistent with biological functions. The qualitative pattern matching classification and hierarchical clustering analyses for the intracellular metabolome identified the metabolite clusters whose dynamic behaviors depend on NaCl and trehalose. The volcano plot revealed several reporter metabolites whose dynamics greatly change between in the NaCl and trehalose cultures. The elastic net identified some critical, intracellular metabolites that are distinct between the NaCl and trehalose. While a relatively small number of intracellular metabolites related to the cell growth, glucose, glutamine, lactate and ammonium ion concentrations, the mechanism of antibody production was suggested to be very complicated or not to be explained by elastic net regression analysis. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Reconstruction of Oryza sativa indica Genome Scale Metabolic Model and Its Responses to Varying RuBisCO Activity, Light Intensity, and Enzymatic Cost Conditions

    Directory of Open Access Journals (Sweden)

    Ankita Chatterjee

    2017-11-01

    Full Text Available To combat decrease in rice productivity under different stresses, an understanding of rice metabolism is needed. Though there are different genome scale metabolic models (GSMs of Oryza sativa japonica, no GSM with gene-protein-reaction association exist for Oryza sativa indica. Here, we report a GSM, OSI1136 of O.s. indica, which includes 3602 genes and 1136 metabolic reactions and transporters distributed across the cytosol, mitochondrion, peroxisome, and chloroplast compartments. Flux balance analysis of the model showed that for varying RuBisCO activity (Vc/Vo (i the activity of the chloroplastic malate valve increases to transport reducing equivalents out of the chloroplast under increased photorespiratory conditions and (ii glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase can act as source of cytosolic ATP under decreased photorespiration. Under increasing light conditions we observed metabolic flexibility, involving photorespiration, chloroplastic triose phosphate and the dicarboxylate transporters of the chloroplast and mitochondrion for redox and ATP exchanges across the intracellular compartments. Simulations under different enzymatic cost conditions revealed (i participation of peroxisomal glutathione-ascorbate cycle in photorespiratory H2O2 metabolism (ii different modes of the chloroplastic triose phosphate transporters and malate valve, and (iii two possible modes of chloroplastic Glu–Gln transporter which were related with the activity of chloroplastic and cytosolic isoforms of glutamine synthetase. Altogether, our results provide new insights into plant metabolism.

  12. Genome-Scale Metabolic Model for the Green Alga Chlorella vulgaris UTEX 395 Accurately Predicts Phenotypes under Autotrophic, Heterotrophic, and Mixotrophic Growth Conditions1

    Science.gov (United States)

    Zuñiga, Cristal; Li, Chien-Ting; Zielinski, Daniel C.; Guarnieri, Michael T.; Antoniewicz, Maciek R.; Zengler, Karsten

    2016-01-01

    The green microalga Chlorella vulgaris has been widely recognized as a promising candidate for biofuel production due to its ability to store high lipid content and its natural metabolic versatility. Compartmentalized genome-scale metabolic models constructed from genome sequences enable quantitative insight into the transport and metabolism of compounds within a target organism. These metabolic models have long been utilized to generate optimized design strategies for an improved production process. Here, we describe the reconstruction, validation, and application of a genome-scale metabolic model for C. vulgaris UTEX 395, iCZ843. The reconstruction represents the most comprehensive model for any eukaryotic photosynthetic organism to date, based on the genome size and number of genes in the reconstruction. The highly curated model accurately predicts phenotypes under photoautotrophic, heterotrophic, and mixotrophic conditions. The model was validated against experimental data and lays the foundation for model-driven strain design and medium alteration to improve yield. Calculated flux distributions under different trophic conditions show that a number of key pathways are affected by nitrogen starvation conditions, including central carbon metabolism and amino acid, nucleotide, and pigment biosynthetic pathways. Furthermore, model prediction of growth rates under various medium compositions and subsequent experimental validation showed an increased growth rate with the addition of tryptophan and methionine. PMID:27372244

  13. Genome-Scale Metabolic Model for the Green Alga Chlorella vulgaris UTEX 395 Accurately Predicts Phenotypes under Autotrophic, Heterotrophic, and Mixotrophic Growth Conditions.

    Science.gov (United States)

    Zuñiga, Cristal; Li, Chien-Ting; Huelsman, Tyler; Levering, Jennifer; Zielinski, Daniel C; McConnell, Brian O; Long, Christopher P; Knoshaug, Eric P; Guarnieri, Michael T; Antoniewicz, Maciek R; Betenbaugh, Michael J; Zengler, Karsten

    2016-09-01

    The green microalga Chlorella vulgaris has been widely recognized as a promising candidate for biofuel production due to its ability to store high lipid content and its natural metabolic versatility. Compartmentalized genome-scale metabolic models constructed from genome sequences enable quantitative insight into the transport and metabolism of compounds within a target organism. These metabolic models have long been utilized to generate optimized design strategies for an improved production process. Here, we describe the reconstruction, validation, and application of a genome-scale metabolic model for C. vulgaris UTEX 395, iCZ843. The reconstruction represents the most comprehensive model for any eukaryotic photosynthetic organism to date, based on the genome size and number of genes in the reconstruction. The highly curated model accurately predicts phenotypes under photoautotrophic, heterotrophic, and mixotrophic conditions. The model was validated against experimental data and lays the foundation for model-driven strain design and medium alteration to improve yield. Calculated flux distributions under different trophic conditions show that a number of key pathways are affected by nitrogen starvation conditions, including central carbon metabolism and amino acid, nucleotide, and pigment biosynthetic pathways. Furthermore, model prediction of growth rates under various medium compositions and subsequent experimental validation showed an increased growth rate with the addition of tryptophan and methionine. © 2016 American Society of Plant Biologists. All rights reserved.

  14. Changes in the metabolic footprint of placental explant-conditioned medium cultured in different oxygen tensions from placentas of small for gestational age and normal pregnancies.

    LENUS (Irish Health Repository)

    Horgan, R P

    2012-01-31

    Being born small for gestational age (SGA) confers significantly increased risks of perinatal morbidity and mortality. Accumulating evidence suggests that an SGA fetus results from a poorly perfused and abnormally developed placenta. Some of the placental features seen in SGA, such as abnormal cell turnover and impaired nutrient transport, can be reproduced by culture of placental explants in hypoxic conditions. Metabolic footprinting offers a hypothesis-generating strategy to investigate factors absorbed by and released from this tissue in vitro. Previously, metabolic footprinting of the conditioned culture media has identified differences in placental explants cultured under normoxic and hypoxic conditions and between normal pregnancies and those complicated by pre-eclampsia. In this study we aimed to examine the differences in the metabolic footprint of placental villous explants cultured at different oxygen (O(2)) tensions between women who deliver an SGA baby (n = 9) and those from normal controls (n = 8). Placental villous explants from cases and controls were cultured for 96 h in 1% (hypoxic), 6% (normoxic) and 20% (hyperoxic) O(2). Metabolic footprints were analysed by Ultra Performance Liquid Chromatography coupled to an electrospray hybrid LTQ-Orbitrap Mass Spectrometry (UPLC-MS). 574 metabolite features showed significant difference between SGA and normal at one or more of the oxygen tensions. SGA explant media cultured under hypoxic conditions was observed, on a univariate level, to exhibit the same metabolic signature as controls cultured under normoxic conditions in 49% of the metabolites of interest, suggesting that SGA tissue is acclimatised to hypoxic conditions in vivo. No such behaviour was observed under hyperoxic culture conditions. Glycerophospholipid and tryptophan metabolism were highlighted as areas of particular interest.

  15. Effect of culture conditions on producing and uptake hydrogen flux of biohydrogen fermentation by metabolic flux analysis method.

    Science.gov (United States)

    Niu, Kun; Zhang, Xu; Tan, Wen-Song; Zhu, Ming-Long

    2011-08-01

    In this work, metabolic flux analysis (MFA) method was used to estimate the effects of the culture conditions on both the producing and uptake hydrogen flux inside the cell of Klebsiella pneumoniae ECU-15. The results indicated that higher temperature could reduce the amount of the uptake hydrogen and enhance the hydrogen production from the NADH pathway. Moreover, both the producing hydrogen flux from formate and the uptake hydrogen flux were attained to the maximum at pH 7.0-7.5. The producing hydrogen flux was higher at 5g/L initial glucose than that of the other concentrations, and the uptake hydrogen flux showed the minimum value under the same condition. The apparent hydrogen generation was caused by the combined action of producing hydrogenase, uptake hydrogenase and bidirectional hydrogenase. These results were helpful to deeply understand the mechanism of the biohydrogen evolving process and establish the suitable molecular strategies for improving hydrogen production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Body condition score at calving affects systemic and hepatic transcriptome indicators of inflammation and nutrient metabolism in grazing dairy cows.

    Science.gov (United States)

    Akbar, H; Grala, T M; Vailati Riboni, M; Cardoso, F C; Verkerk, G; McGowan, J; Macdonald, K; Webster, J; Schutz, K; Meier, S; Matthews, L; Roche, J R; Loor, J J

    2015-02-01

    Calving body condition score (BCS) is an important determinant of early-lactation dry matter intake, milk yield, and disease incidence. The current study investigated the metabolic and molecular changes induced by the change in BCS. A group of cows of mixed age and breed were managed from the second half of the previous lactation to achieve mean group BCS (10-point scale) that were high (HBCS, 5.5; n=20), medium (MBCS, 4.5; n=18), or low (LBCS, 3.5; n=19). Blood was sampled at wk -4, -3, -2, 1, 3, 5, and 6 relative to parturition to measure biomarkers of energy balance, inflammation, and liver function. Liver was biopsied on wk 1, 3, and 5 relative to parturition, and 10 cows per BCS group were used for transcript profiling via quantitative PCR. Cows in HBCS and MBCS produced more milk and had greater concentrations of nonesterified fatty acids and β-hydroxybutyrate postpartum than LBCS. Peak concentrations of nonesterified fatty acids and β-hydroxybutyrate and greater hepatic triacylglycerol concentrations were recorded in HBCS at wk 3. Consistent with blood biomarkers, HBCS and MBCS had greater expression of genes associated with fatty acid oxidation (CPT1A, ACOX1), ketogenesis (HMGCS2), and hepatokines (FGF21, ANGPTL4), whereas HBCS had the lowest expression of APOB (lipoprotein transport). Greater expression during early lactation of BBOX1 in MBCS and LBCS suggested greater de novo carnitine synthesis. The greater BCS was associated with lower expression of growth hormone/insulin-like growth factor-1 signaling axis genes (GHR1A, IGF1, and IGFALS) and greater expression of gluconeogenic genes. These likely contributed to the higher milk production and greater gluconeogenesis. Despite greater serum haptoglobin around calving, cows in HBCS and MBCS had greater blood albumin. Cows in MBCS, however, had a higher albumin:globulin ratio, probably indicating a less pronounced inflammatory status and better liver function. The marked decrease in expression of NFKB1

  17. Overexpression of genes encoding glycolytic enzymes in Corynebacterium glutamicum enhances glucose metabolism and alanine production under oxygen deprivation conditions.

    Science.gov (United States)

    Yamamoto, Shogo; Gunji, Wataru; Suzuki, Hiroaki; Toda, Hiroshi; Suda, Masako; Jojima, Toru; Inui, Masayuki; Yukawa, Hideaki

    2012-06-01

    We previously reported that Corynebacterium glutamicum strain ΔldhAΔppc+alaD+gapA, overexpressing glyceraldehyde-3-phosphate dehydrogenase-encoding gapA, shows significantly improved glucose consumption and alanine formation under oxygen deprivation conditions (T. Jojima, M. Fujii, E. Mori, M. Inui, and H. Yukawa, Appl. Microbiol. Biotechnol. 87:159-165, 2010). In this study, we employ stepwise overexpression and chromosomal integration of a total of four genes encoding glycolytic enzymes (herein referred to as glycolytic genes) to demonstrate further successive improvements in C. glutamicum glucose metabolism under oxygen deprivation. In addition to gapA, overexpressing pyruvate kinase-encoding pyk and phosphofructokinase-encoding pfk enabled strain GLY2/pCRD500 to realize respective 13% and 20% improved rates of glucose consumption and alanine formation compared to GLY1/pCRD500. Subsequent overexpression of glucose-6-phosphate isomerase-encoding gpi in strain GLY3/pCRD500 further improved its glucose metabolism. Notably, both alanine productivity and yield increased after each overexpression step. After 48 h of incubation, GLY3/pCRD500 produced 2,430 mM alanine at a yield of 91.8%. This was 6.4-fold higher productivity than that of the wild-type strain. Intracellular metabolite analysis showed that gapA overexpression led to a decreased concentration of metabolites upstream of glyceraldehyde-3-phosphate dehydrogenase, suggesting that the overexpression resolved a bottleneck in glycolysis. Changing ratios of the extracellular metabolites by overexpression of glycolytic genes resulted in reduction of the intracellular NADH/NAD(+) ratio, which also plays an important role on the improvement of glucose consumption. Enhanced alanine dehydrogenase activity using a high-copy-number plasmid further accelerated the overall alanine productivity. Increase in glycolytic enzyme activities is a promising approach to make drastic progress in growth-arrested bioprocesses.

  18. The degeneration of biological cardiovascular prostheses under pro-calcific metabolic conditions in a small animal model.

    Science.gov (United States)

    Assmann, Alexander; Zwirnmann, Kai; Heidelberg, Friederike; Schiffer, Franziska; Horstkötter, Kim; Munakata, Hiroshi; Gremse, Felix; Barth, Mareike; Lichtenberg, Artur; Akhyari, Payam

    2014-08-01

    In order to allow for a comparative evaluation of the in vivo degeneration of biological and tissue-engineered heart valves and vascular grafts, a small animal model of accelerated cardiovascular calcification is desired. Wistar rats (n = 102; 6 groups) were fed ad libitum with regular chow and 5 different regimens of pro-calcific diet supplemented with combinations of vitamin D (VD), cholesterol (CH) and dicalcium phosphate (PH). Moreover, cryopreserved (n = 7) or detergent-decellularized rat aortic conduit grafts (n = 6) were infrarenally implanted in Wistar rats under severely pro-calcific conditions. The follow-up lasted up to 12 weeks. High-dose application of VD (300,000 IU/kg), CH (2%) and PH (1.5%) resulted in elevated serum calcium and cholesterol levels as well as LDL/HDL ratio. It increased the tissue MMP activity visualized by in situ zymography and caused significantly aggravated calcification of the native aortic valve as well as the aortic wall as assessed by histology and micro-computed tomography. (Immuno)histology and quantitative real-time PCR revealed chondro-osteogenic cell transformation, lipid deposition, nitrosative stress and low-level inflammation to be involved in the formation of calcific lesions. Despite pro-calcific in vivo conditions, decellularization significantly reduced calcification, inflammation and intimal hyperplasia in aortic conduit implants. A well balanced dietary trigger for pathologic metabolic conditions may represent an appropriate mid-term treatment to induce calcifying degeneration of aortic valves as well as vascular structures in the systemic circulation in rats. With respect to experimental investigation focusing on calcifying degeneration of native or prosthetic tissue, this regimen may serve as a valuable tool with a rapid onset and multi-facetted character of cardiovascular degeneration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. A Review of Fatigue Condition in Patients with Type II Diabetes in Isfahan Endocrine and Metabolism Research Center

    Directory of Open Access Journals (Sweden)

    Nasim Vard

    2016-07-01

    Full Text Available Complications of Diabetes such as Fatigue is a serious obstacle hindering the enhancement of health behaviors, including participation in Diabetes self-care programs, and is considered as a challenging problem for nurses and health-care providers in the process of diseases’ treatments and therapies. These complications not only influence the patients’ quality of life, but also, increases the risk of complications. Hence, regarding the importance of the role of fatigue and its subsequent effects on Diabetes’ control as well as the paucity of studies carried out in this field, the current research intended to review fatigue condition in patients with type II Diabetes in Isfahan Endocrine and Metabolism Research Center. The nature of this study is a Quantitative-Descriptive research. For the purpose of the present study, 195 patients with type II Diabetes were selected as the target sample population, based on Non-probability Convenience Sampling Method, from Isfahan Endocrine and Metabolism Research Center. To collect the research data, the researcher used a two-part written questionnaire encompassing Personal Information and Multidimensional Fatigue Symptom Inventory- Short Form (MFSI-SF as the data collection tool. Each of the participants in the present research were briefly advised about the nature and objectives of the research and they were interviewed by the researcher to complete the questionnaire after consent reached with the patients. The collected data was analyzed by SPSS16 statistical analysis software; accordingly the significance level of all the tests was estimated as P˂0.05. The results of the data analysis showed that %85.1 of the patients suffered from fatigue. There was a statistically significant difference between the mean of the severity of fatigue condition between female and male patients in the present study, i.e.23.22 ± 17.49 for women and 13.24 ± 17.73 for men, indexing a significance level of P˂0

  20. conditions

    Directory of Open Access Journals (Sweden)

    M. Venkatesulu

    1996-01-01

    Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.

  1. Saccharomyces cerevisiae and metabolic activators: HXT3 gene expression and fructose/glucose discrepancy in sluggish fermentation conditions.

    Science.gov (United States)

    Díaz-Hellín, Patricia; Naranjo, Victoria; Úbeda, Juan; Briones, Ana

    2016-12-01

    When exposed to mixtures of glucose and fructose, as occurs during the fermentation of grape juice into wine, Saccharomyces cerevisiae uses these sugars at different rates. Moreover, glucose and fructose are transported by the same hexose transporters (HXT), which present a greater affinity for glucose, so that late in fermentation, fructose becomes the predominant sugar. Only a few commercial fermentation activators are available to optimally solve the problems this entails. The aim of this study was to investigate the relation between HXT3 gene expression and fructose/glucose discrepancy in two different media inoculated with a commercial wine strain of S. cerevisiae in the presence of three metabolic activators. Fermentation kinetics, vitality and major metabolites were also measured. Rehydration with ergosterol improved the area under the curve and the growth rate (µ max ) in both studied media. Also, the fructose/glucose discrepancy values were improved with all activator treatments, highlighting rehydration in the presence of ascorbic acid. The yeast rehydration process was demonstrated to influence HXT3 expression under the studied conditions. Tetrahydrofolic acid treatment greatly influenced HXT3 gene expression, especially on the 12th day of the fermentation process. To a lesser extent, ergosterol and ascorbic acid also improved this parameter.

  2. The diel imprint of leaf metabolism on the δ13 C signal of soil respiration under control and drought conditions.

    Science.gov (United States)

    Barthel, Matthias; Hammerle, Albin; Sturm, Patrick; Baur, Thomas; Gentsch, Lydia; Knohl, Alexander

    2011-12-01

    Recent (13) CO(2) canopy pulse chase labeling studies revealed that photosynthesis influences the carbon isotopic composition of soil respired CO(2) (δ(13) C(SR)) even on a diel timescale. However, the driving mechanisms underlying these short-term responses remain unclear, in particular under drought conditions. The gas exchange of CO(2) isotopes of canopy and soil was monitored in drought/nondrought-stressed beech (Fagus sylvatica) saplings after (13) CO(2) canopy pulse labeling. A combined canopy/soil chamber system with gas-tight separated soil and canopy compartments was coupled to a laser spectrometer measuring mixing ratios and isotopic composition of CO(2) in air at high temporal resolution. The measured δ(13) C(SR) signal was then explained and substantiated by a mechanistic carbon allocation model. Leaf metabolism had a strong imprint on diel cycles in control plants, as a result of an alternating substrate supply switching between sugar and transient starch. By contrast, diel cycles in drought-stressed plants were determined by the relative contributions of autotrophic and heterotrophic respiration throughout the day. Drought reduced the speed of the link between photosynthesis and soil respiration by a factor of c. 2.5, depending on the photosynthetic rate. Drought slows the coupling between photosynthesis and soil respiration and alters the underlying mechanism causing diel variations of δ(13) C(SR). © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  3. Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions.

    Science.gov (United States)

    Gregersen, Nikolaj T; Bitz, Christian; Krog-Mikkelsen, Inger; Hels, Ole; Kovacs, Eva M R; Rycroft, Jane A; Frandsen, Erik; Mela, David J; Astrup, Arne

    2009-10-01

    Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE) and fat oxidation over a single day. Fifteen healthy, normal-weight males received capsules containing placebo, caffeine alone (150 mg), or caffeine plus a catechin mixture (600 mg) enriched in either epigallocatechin-3-gallate (EGCG), epigallocatechin or a mix of catechins, in a randomised cross-over double-blinded design. On each test day EE, respiratory quotient (RQ) and substrate oxidation were measured under sedentary conditions in a respiratory chamber for 13.5 h. We found no significant treatment effect on EE (P = 0.20) or RQ (P = 0.68). EGCG with caffeine insignificantly raised EE and fat oxidation v. caffeine-only and placebo (EE 5.71 (SE 0.12) v. 5.68 (SE 0.14) v. 5.59 (SE 0.13) MJ/12.5 h, respectively; fat oxidation 84.8 (SE 5.2) v. 80.7 (SE 4.7) v. 76.8 (SE 4.0) g/12.5 h). Catechin/caffeine combinations at these dosages and mode of application had non-significant acute effects on EE and fat oxidation. The maximum observed effect on EE of about 2 % could still be meaningful for energy balance over much longer period of exposure. However, higher short-term effects reported in the literature may reflect variations in green tea extracts, added caffeine, or synergies with physical activity. The specific mechanisms and conditions that may underpin observed longer-term benefits of catechin-enriched green tea consumption on body composition remain to be confirmed.

  4. Influence of culture conditions on growth and protein metabolism in chlorella pyranosides; Influencia de las condiciones de cultivo sobre el crecimiento y metabolismo proteico de chlorella pyrenoidosa

    Energy Technology Data Exchange (ETDEWEB)

    Mazon Matanzo, M. P.; Fernandez Gonzalez, J.; Batuecas Suarez, B.

    1981-07-01

    Growth and protein metabolism of Chlorella pyranoside under different conditions of temperature, photo period and CO{sub 2} concentration was studied. The optimum of biomass production was observed at 25 degree centigree, 40.000 ppm of CO{sub 2} in air and a 20 h. light period, followed of 4 h. of darkness. Some variations in free aminoacids content was observed under different conditions but no change did occur in protein. (Author) 68 refs.

  5. Anthropogenic changes to seawater buffer capacity combined with natural reef metabolism induce extreme future coral reef CO2 conditions.

    Science.gov (United States)

    Shaw, Emily C; McNeil, Ben I; Tilbrook, Bronte; Matear, Richard; Bates, Michael L

    2013-05-01

    Ocean acidification, via an anthropogenic increase in seawater carbon dioxide (CO2 ), is potentially a major threat to coral reefs and other marine ecosystems. However, our understanding of how natural short-term diurnal CO2 variability in coral reefs influences longer term anthropogenic ocean acidification remains unclear. Here, we combine observed natural carbonate chemistry variability with future carbonate chemistry predictions for a coral reef flat in the Great Barrier Reef based on the RCP8.5 CO2 emissions scenario. Rather than observing a linear increase in reef flat partial pressure of CO2 (pCO2 ) in concert with rising atmospheric concentrations, the inclusion of in situ diurnal variability results in a highly nonlinear threefold amplification of the pCO2 signal by the end of the century. This significant nonlinear amplification of diurnal pCO2 variability occurs as a result of combining natural diurnal biological CO2 metabolism with long-term decreases in seawater buffer capacity, which occurs via increasing anthropogenic CO2 absorption by the ocean. Under the same benthic community composition, the amplification in the variability in pCO2 is likely to lead to exposure to mean maximum daily pCO2 levels of ca. 2100 μatm, with corrosive conditions with respect to aragonite by end-century at our study site. Minimum pCO2 levels will become lower relative to the mean offshore value (ca. threefold increase in the difference between offshore and minimum reef flat pCO2 ) by end-century, leading to a further increase in the pCO2 range that organisms are exposed to. The biological consequences of short-term exposure to these extreme CO2 conditions, coupled with elevated long-term mean CO2 conditions are currently unknown and future laboratory experiments will need to incorporate natural variability to test this. The amplification of pCO2 that we describe here is not unique to our study location, but will occur in all shallow coastal environments where high

  6. Localized corrosion of carbon steels due to sulfate-reducing bacteria. Development of a specific sensor; Corrosion localisee des aciers au carbone induite par des bacteries sulfato-reductrices. Developpement d'un capteur specifique

    Energy Technology Data Exchange (ETDEWEB)

    Monfort Moros, N.

    2001-11-01

    This work concerns the microbiologically influenced corrosion of carbon steels in saline anaerobic media (3% of NaCl) containing sulfato-reducing bacteria (Desulfovibrio gabonensis, DSM 10636). In these media, extreme localised corrosion occurs by pitting under the bio-film covering the metallic substrate. A sensor with concentric electrodes was designed to initiate the phenomenon of bio-corrosion, recreating the favourable conditions for growth of a corrosion pit, and then measuring the corrosion current maintained by bacterial activity. The pit initiation was achieved through either of two methods. The electrochemical conditioning involved driving the potential difference between inner and outer electrodes to values corresponding to a galvanic corrosion that can be maintained by the bacterial metabolism. The mechanical process involved removal of a portion of the bio-film by scratching, yielding galvanic potential differences equivalent to that found by the conditioning technique. This protocol was found to be applicable to a bio-corrosion study on industrial site for the monitoring of the metallic structures deterioration (patent EN 00/06114, May 2000). Thereafter, a fundamental application uses the bio-corrosion sensor for Electrochemical Impedance Spectroscopy (EIS), Electrochemical Noise Analysis (ENA) and current density cartography by the means of micro-electrodes. Thus, the EIS technique reveals the importance of the FeS corrosion products for initiation of bio-corrosion start on carbon steel. In addition, depending on the method used to create a pit, the ENA gives rise to supplementary processes (gaseous release) disturbing the bio-corrosion detection. The beginning of a bio-corrosion process on a clean surface surrounded with bio-film was confirmed by the current density cartography. These different results establish the sensor with concentric electrodes as an indispensable tool for bio-corrosion studies, both in the laboratory and on industrial sites

  7. Effects of different feeding time and frequency on metabolic conditions and milk production in heat-stressed dairy cows

    Science.gov (United States)

    Calamari, L.; Petrera, F.; Stefanini, L.; Abeni, F.

    2013-09-01

    The aim of this paper was to evaluate the effects of three different feeding management (FM) schedules on physiological markers of heat stress (HS), metabolic conditions, milk yield and quality during the hot season in dairy cows. The study involved 27 mid-lactating cows, subdivided in three homogeneous groups differing in feeding time and frequency: total mixed ration (TMR) delivered once daily in the morning (M); twice daily, half in the morning and half in the evening (ME); once daily in the evening (E). During the trial, blood samples were collected in the morning (a.m.) and in the evening (p.m.), breathing rate (BR), rectal temperature (RT), and milk yield were recorded and individual milk samples were collected. Microclimate data indicated that cows were subjected to mild-moderate HS. During the hotter days, cows receiving M treatment showed higher values of RT (38.97 °C vs 38.68 °C and 38.62 °C, in ME and E) and BR (71.44 vs 66.52 and 65.26 breaths min-1, in ME and E), a.m. plasma glucose was lower in M (3.69 vs 3.83 and 3.83 mmol L-1, in ME and E) and a.m. plasma urea was lower in E (4.82 vs 5.48 and 5.35 mmol L-1, in M and ME). Milk yield was unaffected by FM, as well as milk composition and cheese-making properties. Only milk protein content and yield were higher in M (3.42 vs 3.36 and 3.27 g 100 mL-1; and 1.11 vs 1.08 and 1.02 kg day-1, for ME and E). Our results on cow physiology indicate that M seems a less suitable FM to match cow welfare during the summer season.

  8. Desulfovibrio oceani subsp. oceani sp. nov., subsp. nov. and Desulfovibrio oceani subsp. galateae subsp. nov., novel sulfate-reducing bacteria isolated from the oxygen minimum zone off the coast of Peru.

    Science.gov (United States)

    Finster, Kai W; Kjeldsen, Kasper U

    2010-03-01

    Two deltaproteobacterial sulfate reducers, designated strain I.8.1(T) and I.9.1(T), were isolated from the oxygen minimum zone water column off the coast of Peru at 400 and 500 m water depth. The strains were Gram-negative, vibrio-shaped and motile. Both strains were psychrotolerant, grew optimally at 20 degrees C at pH 7.0-8.0 and at 2.5-3.5% NaCl (w/v). The strains grew by utilizing hydrogen/acetate, C(3-4) fatty acids, amino acids and glycerol as electron acceptors for sulfate reduction. Fumarate, lactate and pyruvate supported fermentative growth. Sulfate, sulfite, thiosulfate and taurin supported growth as electron acceptors. Both strains were catalase-positive and highly oxygen-tolerant, surviving 24 days of exposure to atmospheric concentrations. MK6 was the only respiratory quinone. The most prominent cellular fatty acid was iso-17:1-omega9c (18%) for strain I.8.1(T) and iso-17:0-omega9c (14%) for strain I.9.1(T). The G+C contents of their genomic DNA were 45-46 mol%. Phylogenetic analysis of 16S rRNA and dsrAB gene sequences showed that both strains belong to the genus Desulfovibrio. Desulfovibrio acrylicus DSM 10141(T) and Desulfovibrio marinisediminis JCM 14577(T) represented their closest validly described relatives with pairwise 16S rRNA gene sequence identities of 98-99%. The level of DNA-DNA hybridization between strains I.8.1(T) and I.9.1(T) was 30-38%. The two strains shared 10-26% DNA-DNA relatedness with D. acrylicus. Based on a polyphasic investigation it is proposed that strains I.8.1(T) and I.9.1(T) represent a novel species for which the name Desulfovibrio oceani sp. nov. is proposed with the two subspecies D. oceani subsp. oceani (type strain, I.8.1(T) = DSM 21390(T) = JCM 15970(T)) and D. oceani subsp. galateae (type strain, I.9.1(T) = DSM 21391(T) = JCM 15971(T)).

  9. Real-time PCR quantification and diversity analysis of the functional genes aprA and dsrA of sulfate-reducing bacteria in marine sediments of the Peru continental margin and the Black Sea

    Directory of Open Access Journals (Sweden)

    Axel eSchippers

    2011-12-01

    Full Text Available A quantitative, real-time PCR (Q-PCR assay for the functional gene adenosine 5´-phosphosulfate reductase (aprA of sulfate-reducing bacteria (SRB was designed. This assay was applied together with described Q-PCR assays for dissimilatory sulfite reductase (dsrA and the 16S rRNA gene of total Bacteria to marine sediments from the Peru margin (0 – 121 meters below seafloor (mbsf and the Black Sea (0 – 6 mbsf. Clone libraries of aprA show that all isolated sequences originate from SRB showing a close relationship to aprA of characterised species or form a new cluster with only distant relation to aprA of isolated SRB. Below 40 mbsf no aprA genes could be amplified. This finding corresponds with results of the applied new Q-PCR assay for aprA. In contrast to the aprA the dsrA gene could be amplified up to sediment depths of 121 mbsf. Even in such an extreme environment a high diversity of this gene was detected. The 16S rRNA gene copy numbers of total Bacteria were much higher than those of the functional genes at all sediment depths and used to calculate the proportion of SRB to the total Bacteria. The aprA and dsrA copy numbers comprised in average 0.5 - 1 % of the 16S rRNA gene copy numbers of total Bacteria in the sediments up to a depth of ca. 40 mbsf. Depth profiles of the aprA and dsrA copy numbers were almost equal for all sites. Gene copy numbers decreased concomitantly with depth from around 108 / g sediment close to the sediment surface to less than 105 / g sediment at 5 mbsf. In the zone without detectable sulfate in the pore water from ca. 40 – 121 mbsf (Peru margin ODP site 1227, only dsrA (but not aprA was detected with copy numbers of less than 104 / g sediment, comprising ca. 14 % of the 16S rRNA gene copy numbers of total Bacteria. In this zone sulfate might be provided for SRB by anaerobic sulfide oxidation.

  10. Real-Time PCR Quantification and Diversity Analysis of the Functional Genes aprA and dsrA of Sulfate-Reducing Prokaryotes in Marine Sediments of the Peru Continental Margin and the Black Sea.

    Science.gov (United States)

    Blazejak, Anna; Schippers, Axel

    2011-01-01

    Sulfate-reducing prokaryotes (SRP) are ubiquitous and quantitatively important members in many ecosystems, especially in marine sediments. However their abundance and diversity in subsurface marine sediments is poorly understood. In this study, the abundance and diversity of the functional genes for the enzymes adenosine 5'-phosphosulfate reductase (aprA) and dissimilatory sulfite reductase (dsrA) of SRP in marine sediments of the Peru continental margin and the Black Sea were analyzed, including samples from the deep biosphere (ODP site 1227). For aprA quantification a Q-PCR assay was designed and evaluated. Depth profiles of the aprA and dsrA copy numbers were almost equal for all sites. Gene copy numbers decreased concomitantly with depth from around 10(8)/g sediment close to the sediment surface to less than 10(5)/g sediment at 5 mbsf. The 16S rRNA gene copy numbers of total bacteria were much higher than those of the functional genes at all sediment depths and used to calculate the proportion of SRP to the total Bacteria. The aprA and dsrA copy numbers comprised in average 0.5-1% of the 16S rRNA gene copy numbers of total bacteria in the sediments up to a depth of ca. 40 mbsf. In the zone without detectable sulfate in the pore water from about 40-121 mbsf (Peru margin ODP site 1227), only dsrA (but not aprA) was detected with copy numbers of less than 10(4)/g sediment, comprising ca. 14% of the 16S rRNA gene copy numbers of total bacteria. In this zone, sulfate might be provided for SRP by anaerobic sulfide oxidation. Clone libraries of aprA showed that all isolated sequences originate from SRP showing a close relationship to aprA of characterized species or form a new cluster with only distant relation to aprA of isolated SRP. For dsrA a high diversity was detected, even up to 121 m sediment depth in the deep biosphere.

  11. Recovery of community genomes to assess subsurface metabolic potential: exploiting the capacity of next generation sequencing-based metagenomics

    Science.gov (United States)

    Wrighton, K. C.; Thomas, B.; Miller, C. S.; Sharon, I.; Wilkins, M. J.; VerBerkmoes, N. C.; Handley, K. M.; Lipton, M. S.; Hettich, R. L.; Williams, K. H.; Long, P. E.; Banfield, J. F.

    2011-12-01

    With the goal of developing a deterministic understanding of the microbiological and geochemical processes controlling subsurface environments, groundwater bacterial communities were collected from the Rifle Integrated Field Research Challenge (IFRC) site. Biomass from three temporal acetate-stimulated groundwater samples were collected during a period of dominant Fe(III)-reduction, in a region of the aquifer that had previously received acetate amendment the year prior. Phylogenetic analysis revealed a diverse Bacterial community, notably devoid of Archaea with 249 taxa from 9 Bacterial phyla including the dominance of uncultured candidate divisions, BD1-5, OD1, and OP11. We have reconstructed 86 partial to near-complete genomes and have performed a detailed characterization of the underlying metabolic potential of the ecosystem. We assessed the natural variation and redundancy in multi-heme c-type cytochromes, sulfite reductases, and central carbon metabolic pathways. Deep genomic sampling indicated the community contained various metabolic pathways: sulfur oxidation coupled to microaerophilic conditions, nitrate reduction with both acetate and inorganic compounds as donors, carbon and nitrogen fixation, antibiotic warfare, and heavy-metal detoxification. Proteomic investigations using predicted proteins from metagenomics corroborated that acetate oxidation is coupled to reduction of oxygen, sulfur, nitrogen, and iron across the samples. Of particular interest was the detection of acetate oxidizing and sulfate reducing proteins from a Desulfotalea-like bacterium in all three time points, suggesting that aqueous sulfide produced by active sulfate-reducing bacteria could contribute to abiotic iron reduction during the dominant iron reduction phase. Additionally, proteogenomic analysis verified that a large portion of the community, including members of the uncultivated BD1-5, are obligate fermenters, characterized by the presence of hydrogen-evolving hydrogenases

  12. Chronic Caloric Restriction and Exercise Improve Metabolic Conditions of Dietary-Induced Obese Mice in Autophagy Correlated Manner without Involving AMPK

    Directory of Open Access Journals (Sweden)

    Mingxia Cui

    2013-01-01

    Full Text Available Aim. To investigate the role of AMPK activation and autophagy in mediating the beneficial effects of exercise and caloric restriction in obesity. Methods. Dietary-induced obesity mice were made and divided into 5 groups; one additional group of normal mice serves as control. Mice in each group received different combinations of interventions including low fat diet, caloric restriction, and exercise. Then their metabolic conditions were assessed by measuring serum glucose and insulin, serum lipids, and liver function. AMPK phosphorylation and autophagy activity were detected by western blotting. Results. Obese mice models were successfully induced by high fat diet. Caloric restriction consistently improved the metabolic conditions of the obese mice, and the effects are more prominent than the mice that received only exercise. Also, caloric restriction, exercise, and low fat diet showed a synergistic effect in the improvement of metabolic conditions. Western blotting results showed that this improvement was not related with the activation of AMPK in liver, skeletal muscle, or heart but correlates well with the autophagy activity. Conclusion. Caloric restriction has more prominent beneficial effects than exercise in dietary-induced obese mice. These effects are correlated with the autophagy activity and may be independent of AMPK activation.

  13. Individual condition, standard metabolic rate, and rearing temperature influence steelhead and rainbow trout (Oncorhynchus mykiss) life histories

    Science.gov (United States)

    Matthew R. Sloat; Gordon H. Reeves

    2014-01-01

    We reared juvenile Oncorhychus mykiss with low and high standard metabolic rates (SMR) under alternative thermal regimes to determine how these proximate factors influence life histories in a partially migratory salmonid fish. High SMR significantly decreased rates of freshwater maturation and increased rates of smoltification in females, but not...

  14. Response of genes involved in lipid metabolism in rat epididymal white adipose tissue to different fasting conditions after long-term fructose consumption.

    Science.gov (United States)

    Li, Jin-Xiu; Ke, Da-Zhi; Yao, Ling; Wang, Shang; Ma, Peng; Liu, Li; Zuo, Guo-Wei; Jiang, Li-Rong; Wang, Jian-Wei

    2017-03-04

    There has been much concern regarding the dietary fructose contributes to the development of metabolic syndrome. High-fructose diet changes the expression of genes involved in lipid metabolism. Levels of a number of hepatic lipogenic enzymes are increased by a high-carbohydrate diet in fasted-refed model rats/mice. Both the white adipose tissue (WAT) and the liver play a key role in the maintenance of nutrient homeostasis. Here, the aim of this study was to analyze the expression of key genes related to lipid metabolism in epididymal WAT (eWAT) in response to different fasting condition after long-term chronic fructose consumption. Rats were fed standard chow supplemented with 10% w/v fructose solution for 5 weeks, and killed after chow-fasting and fructose withdrawal (fasting) or chow-fasting and continued fructose (fructose alone) for 14 h. Blood parameters and the expression of genes involved in fatty acid synthesis (ChREBP, SREBP-1c, FAS, SCD1), triglyceride biosynthesis (DGAT-1, DGAT-2) and lipid mobilization (ATGL, HSL) in eWAT were analyzed. In addition, mRNA levels of PPAR-γ, CD36 and LPL were also detected. As expected, fructose alone increased the mRNA expression of FAS, SCD1, and correspondingly decreased ATGL and HSL mRNA levels. However, ChREBP, DGAT-2, ATGL and HSL mRNA levels restored near to normal while FAS and SCD1 tend to basic level under fasting condition. The mRNA expression of SREBP-1c, PPAR-γ and LPL did not changed at any situations but CD36 mRNA decreased remarkably in fructose alone group. In conclusion, these findings demonstrate that genes involved in lipid metabolism in rat eWAT are varied in response to different fasting conditions after long-term fructose consumption. Copyright © 2017. Published by Elsevier Inc.

  15. Temporal variability of intertidal benthic metabolism under emersed conditions in an exposed sandy beach (Wimereux, eastern English Channel, France)

    Science.gov (United States)

    Spilmont, N.; Migné, A.; Lefebvre, A.; Artigas, L. F.; Rauch, M.; Davoult, D.

    2005-02-01

    Benthic community metabolism during emersion was measured in a three-year survey by monitoring CO 2 fluxes in benthic chambers on an exposed sandy beach of the eastern English Channel (Wimereux, France). The three-year chronology of variations in benthic metabolism was characterised by a high variability around a low value for gross community primary production (GCP: 17.47 ± 40.85 mgC m -2 h -1, mean ± SD) and community respiration (CR: 1.66 ± 1.97 mgC m -2 h -1, mean ± SD). Although benthic metabolism remained low most of the time, some high values of primary production and respiration were occasionally detected. High primary production rates (up to 213.94 mgC m -2 h -1 measured at the end of summer) matched with the development of Euglena sp., together with the occurrence of phytoplanktonic species on the sediment, whereas high community respiration rates were detected at the end of spring on Phaeocystis sp. foam deposits. Community respiration was positively correlated with bacterial abundance, suggesting that CR was mainly supported by microfauna.

  16. Dynamic simulation of red blood cell metabolism and its application to the analysis of a pathological condition

    Directory of Open Access Journals (Sweden)

    Kinoshita Ayako

    2005-05-01

    Full Text Available Abstract Background Cell simulation, which aims to predict the complex and dynamic behavior of living cells, is becoming a valuable tool. In silico models of human red blood cell (RBC metabolism have been developed by several laboratories. An RBC model using the E-Cell simulation system has been developed. This prototype model consists of three major metabolic pathways, namely, the glycolytic pathway, the pentose phosphate pathway and the nucleotide metabolic pathway. Like the previous model by Joshi and Palsson, it also models physical effects such as osmotic balance. This model was used here to reconstruct the pathology arising from hereditary glucose-6-phosphate dehydrogenase (G6PD deficiency, which is the most common deficiency in human RBC. Results Since the prototype model could not reproduce the state of G6PD deficiency, the model was modified to include a pathway for de novo glutathione synthesis and a glutathione disulfide (GSSG export system. The de novo glutathione (GSH synthesis pathway was found to compensate partially for the lowered GSH concentrations resulting from G6PD deficiency, with the result that GSSG could be maintained at a very low concentration due to the active export system. Conclusion The results of the simulation were consistent with the estimated situation of real G6PD-deficient cells. These results suggest that the de novo glutathione synthesis pathway and the GSSG export system play an important role in alleviating the consequences of G6PD deficiency.

  17. Cyanobacterial photosynthesis under sulfidic conditions: insights from the isolate Leptolyngbya sp. strain hensonii

    Science.gov (United States)

    Hamilton, Trinity L; Klatt, Judith M; de Beer, Dirk; Macalady, Jennifer L

    2018-01-01

    We report the isolation of a pinnacle-forming cyanobacterium isolated from a microbial mat covering the sediment surface at Little Salt Spring—a flooded sinkhole in Florida with a perennially microoxic and sulfidic water column. The draft genome of the isolate encodes all of the enzymatic machinery necessary for both oxygenic and anoxygenic photosynthesis, as well as genes for methylating hopanoids at the C-2 position. The physiological response of the isolate to H2S is complex: (i) no induction time is necessary for anoxygenic photosynthesis; (ii) rates of anoxygenic photosynthesis are regulated by both H2S and irradiance; (iii) O2 production is inhibited by H2S concentrations as low as 1 μM and the recovery rate of oxygenic photosynthesis is dependent on irradiance; (iv) under the optimal light conditions for oxygenic photosynthesis, rates of anoxygenic photosynthesis are nearly double those of oxygenic photosynthesis. We hypothesize that the specific adaptation mechanisms of the isolate to H2S emerged from a close spatial interaction with sulfate-reducing bacteria. The new isolate, Leptolyngbya sp. strain hensonii, is not closely related to other well-characterized Cyanobacteria that can perform anoxygenic photosynthesis, which further highlights the need to characterize the diversity and biogeography of metabolically versatile Cyanobacteria. The isolate will be an ideal model organism for exploring the adaptation of Cyanobacteria to sulfidic conditions. PMID:29328062

  18. Metabolic Changes during Storage of Brassica napus Seeds under Moist Conditions and the Consequences for the Sensory Quality of the Resulting Virgin Oil.

    Science.gov (United States)

    Bonte, Anja; Schweiger, Rabea; Pons, Caroline; Wagner, Claudia; Brühl, Ludger; Matthäus, Bertrand; Müller, Caroline

    2017-12-20

    Virgin rapeseed (Brassica napus) oil is a valuable niche product, if delivered with a high quality. In this study, the effects of moist storage of B. napus seeds for 1 to 4 days on the seed metabolome and the chemo-sensory properties of the produced oils were determined. The concentrations of several primary metabolites, including monosaccharides and amino acids, rapidly increased in the seeds, probably indicating the breakdown of storage compounds to support seed germination. Seed concentrations of indole glucosinolates increased with a slight time offset suggesting that amino acids may be used to modify secondary metabolism. The volatile profiles of the oils were pronouncedly influenced by moist seed storage, with the sensory quality of the oils decreasing. This study provides a direct time-resolved link between seed metabolism under moist conditions and the quality of the resulting oils, thereby emphasizing the crucial role of dry seed storage in ensuring high oil quality.

  19. Pluripotent and Metabolic Features of Two Types of Porcine iPSCs Derived from Defined Mouse and Human ES Cell Culture Conditions.

    Science.gov (United States)

    Zhang, Wei; Pei, Yangli; Zhong, Liang; Wen, Bingqiang; Cao, Suying; Han, Jianyong

    2015-01-01

    The domestic pig is an excellent animal model for stem cell research and clinical medicine. There is still no suitable culture condition to generate authentic porcine embryonic stem cells (pESCs) and high quality porcine induced pluripotent stem cells (piPSCs). In this study, we found that culture conditions affected pluripotent and metabolic features of piPSCs. Using defined human embryonic stem cell (hESC) and mouse ESC (mESC) culture conditions, we generated two types of piPSCs, one of which was morphologically similar to hESCs (here called hpiPSCs), the other resembled mESCs (here called mpiPSCs). Transcriptome analysis and signaling pathway inhibition results suggested that mpiPSCs shared more of mESC signaling pathways, such as the BMP pathway and JAK/STAT pathway and hpiPSCs shared more hESC signaling pathways, such as the FGF pathway. Importantly, the mpiPSCs performed embryonic chimera incorporation more efficiently than the hpiPSCs did. In addition, the mpiPSCs showed mitochondrial features of naive ESCs and lipid droplets accumulation. These evidences may facilitate understanding of the gene regulation network and metabolism in piPSCs and promote derivation of bona fide pESCs for translational medicine.

  20. Pluripotent and Metabolic Features of Two Types of Porcine iPSCs Derived from Defined Mouse and Human ES Cell Culture Conditions.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available The domestic pig is an excellent animal model for stem cell research and clinical medicine. There is still no suitable culture condition to generate authentic porcine embryonic stem cells (pESCs and high quality porcine induced pluripotent stem cells (piPSCs. In this study, we found that culture conditions affected pluripotent and metabolic features of piPSCs. Using defined human embryonic stem cell (hESC and mouse ESC (mESC culture conditions, we generated two types of piPSCs, one of which was morphologically similar to hESCs (here called hpiPSCs, the other resembled mESCs (here called mpiPSCs. Transcriptome analysis and signaling pathway inhibition results suggested that mpiPSCs shared more of mESC signaling pathways, such as the BMP pathway and JAK/STAT pathway and hpiPSCs shared more hESC signaling pathways, such as the FGF pathway. Importantly, the mpiPSCs performed embryonic chimera incorporation more efficiently than the hpiPSCs did. In addition, the mpiPSCs showed mitochondrial features of naive ESCs and lipid droplets accumulation. These evidences may facilitate understanding of the gene regulation network and metabolism in piPSCs and promote derivation of bona fide pESCs for translational medicine.

  1. Pyruvate dehydrogenase complex regulator (PdhR) gene deletion boosts glucose metabolism in Escherichia coli under oxygen-limited culture conditions.

    Science.gov (United States)

    Maeda, Soya; Shimizu, Kumiko; Kihira, Chie; Iwabu, Yuki; Kato, Ryuichi; Sugimoto, Makoto; Fukiya, Satoru; Wada, Masaru; Yokota, Atsushi

    2017-04-01

    Pyruvate dehydrogenase complex regulator (PdhR) is a transcriptional regulator that negatively regulates formation of pyruvate dehydrogenase complex (PDHc), NADH dehydrogenase (NDH)-2, and cytochrome bo 3 oxidase in Escherichia coli. To investigate the effects of a PdhR defect on glucose metabolism, a pdhR deletion mutant was derived from the wild-type E. coli W1485 strain by λ Red-mediated recombination. While no difference in the fermentation profiles was observed between the two strains under oxygen-sufficient conditions, under oxygen-limited conditions, the growth level of the wild-type strain was significantly decreased with retarded glucose consumption accompanied by by-production of substantial amounts of pyruvic acid and acetic acid. In contrast, the mutant grew and consumed glucose more efficiently than did the wild-type strain with enhanced respiration, little by-production of pyruvic acid, less production yield and rates of acetic acid, thus displaying robust metabolic activity. As expected, increased activities of PDHc and NDH-2 were observed in the mutant. The increased activity of PDHc may explain the loss of pyruvic acid by-production, probably leading to decreased acetic acid formation, and the increased activity of NDH-2 may explain the enhanced respiration. Measurement of the intracellular NAD + /NADH ratio in the mutant revealed more oxidative or more reductive intracellular environments than those in the wild-type strain under oxygen-sufficient and -limited conditions, respectively, suggesting another role of PdhR: maintaining redox balance in E. coli. The overall results demonstrate the biotechnological advantages of pdhR deletion in boosting glucose metabolism and also improve our understanding of the role of PdhR in bacterial physiology. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Influence of dietary chromium yeast supplementation on apparent trace elements metabolism in growing camel (Camelus dromedarius) reared under hot summer conditions.

    Science.gov (United States)

    Alhidary, Ibrahim A; Alsofi, M A; Abdoun, K A; Samara, E M; Okab, A B; Al-Haidary, A A

    2017-11-07

    This study aimed to evaluate the effect of dietary chromium (Cr) supplementation on the apparent metabolism of some trace elements in camel calves reared under hot summer conditions. The study was conducted on a total of 15 male camel calves (5-6 months old) reared under hot summer conditions for 12 weeks. The animals were housed individually under shelter and divided into three dietary treatment groups (diets supplemented with 0.0, 0.5, or 1.0 mg Cr/kg DM), five animals each. At the end of the study, a metabolic trial was conducted on all camels for the evaluation of trace elements metabolism. Cr excretion, absorption, and retention showed an increasing trend with the increasing level of dietary Cr supplementation. Dietary Cr supplementation at 0.5 mg Cr/kg DM to camel calves resulted in a significant (P < 0.05) increase in Cu and an increasing trend in Zn and Mn excretion via urine and feces. However, Fe retention increased significantly (P < 0.05) in camel calves fed on diet supplemented with Cr. Dietary Cr supplementation to camel calves resulted in an increasing trend of plasma Cr concentration, while plasma concentration of Cu and Zn tended to decrease and without any effect on plasma Fe concentration. The results of the present study suggests that care should be taken for the negative interaction of Cr with the utilization of other trace elements, in cases where Cr is supplemented to the diet as a feed additive to promote growth and immunity under hot climatic conditions.

  3. Dynamics of indicators of a metabolic exchange and condition of blood circulation of the bottom extremities after traction extension at patients with lumbar and sacral dorsopathy

    OpenAIRE

    Kotenko К.V.; Korchazhkina N.B.; Petrova М.S.; Ruzova Т.К.

    2013-01-01

    Aim: to study influence of traction therapy in a pulse mode in a complex with electrotherapy on a condition of blood circulation of the bottom extremities and level of a metabolic exchange. Material and methods. There had been examined 120 patients with a lumbar and sacral dorsopathy aged from 22 to 69 years (middle age of 49,5 years) with prescription of a disease from 1 to 5 years, among them men of 34,2%, women of 65,8%. Results. The analysis of effects of various medical methods on a cond...

  4. Supplemental feeding with glycerol or propylene glycol of dairy cows in early lactation - Effects on metabolic status, body condition, and milk yield

    DEFF Research Database (Denmark)

    Lomander, H; Frössling, J; Ingvartsen, Klaus Lønne

    2012-01-01

    The objective of this field study was to evaluate the effect of supplemental feeding with glycerol or propylene glycol to dairy cows in early lactation on metabolic status, body condition and milk yield. In total, 673 newly calved cows from 12 commercial Swedish dairy herds were randomized to daily...... supplementation with 450 g of glycerol (GLY), 300 g of propylene glycol (PG), or nothing (control, CON). Supplements were fed twice daily from 0 to 21 d in milk (DIM) as a top dress on concentrates. For each cow, data on parity, breed, calving date, monthly test-day milk yield, and cases of diseases were...

  5. Effects of Varroa destructor on temperature and humidity conditions and expression of energy metabolism genes in infested honeybee colonies.

    Science.gov (United States)

    Hou, C S; Li, B B; Deng, S; Diao, Q Y

    2016-09-23

    Varroa destructor mites pose an increasing global threat to the apicultural industry and agricultural ecology; however, the issue of whether certain environmental factors reflect the level of mite infection is far from resolved. Here, a wireless sensor network (WSN) system was used to examine how V. destructor, which has vital impacts on honeybee (Apis mellifera) health and survival, affects the temperature and humidity of honeybee hives in a field experiment. This approach may facilitate early identification of V. destructor in hives, and thus enable timely remedial action. Using quantitative PCR, we also evaluated the expression of two genes, adipokinetic hormone (AKH) and adipokinetic hormone receptor (AKHR).The results showed that temperature in highly infested broods was higher than that in broods with low infestation. Moreover, mite infection in honeybee colonies was positively correlated with temperature but negatively correlated with humidity (P Varroa infection not only causes changes in temperature inside honeybee colonies, but also affects the expression of honeybee energy metabolism genes.

  6. Metabolic and functional phenotypic profiling of Drosophila melanogaster reveals reduced sex differentiation under stressful environmental conditions

    DEFF Research Database (Denmark)

    Ørsted, Michael; Malmendal, Anders; Muñoz, Joaquin

    2017-01-01

    sexual dimorphism in stressful environment might be caused by a lower investment in sex specific characteristics in harsh environments, and our results provide support for the longstanding idea that ecological factors are important for shaping sexual dimorphism and possibly sexual selection.......Strong sexual dimorphism is commonly observed across species and e.g. trade-offs between reproduction and maintenance are thought to explain this dimorphism. Here we test how the metabolic and functional phenotypic responses to varying types of environmental stress differ in male and female...... Drosophila melanogaster (Diptera: Drosophilidae), and how this impacts the magnitude of sexual dimorphism. Experimental stressors that we exposed flies to during development were heat stress, poor nutrition, high acidity, high levels of ammonia and ethanol. Emerged male and female flies from the different...

  7. Metabolic and cardiorespiratory reactions in tennis-players in laboratory testing and under sport-specific conditions.

    Science.gov (United States)

    Smekal, G; Baron, R; Pokan, R; Dirninger, K; Bachl, N

    1995-01-01

    Metabolic and cardiorespiratory reactions were investigated during a sport-specific incremental field test (FT) for tennis and compared with a treadmill step test (TT) in a group of 13 trained male tennis players. In both the FT and the TT lactate acid (La), heart rate and oxygen uptake (VO2) were measured. VO2 was determined using a portable telemetric system (K2, Cosmed, Italy). Aerobic- (AT) and anaerobic threshold (ANT) at a blood lactate concentration of 2 mmol/l and at 4 mmol/l respectively was indicated to characterize the endurance capacity of the athletes. In both FT and TT, minimum value of lactate equivalent (LE(min)), measured in every exercise test, was also registered. At AT and ANT values for HR (AT: p advantage of combining an individually intensity-controlled specific endurance training for tennis with a training of technical skills.

  8. Metabolically active extracellular vesicles released from hepatocytes under drug-induced liver-damaging conditions modify serum metabolome and might affect different pathophysiological processes.

    Science.gov (United States)

    Royo, Felix; Palomo, Laura; Mleczko, Justyna; Gonzalez, Esperanza; Alonso, Cristina; Martínez, Ibon; Pérez-Cormenzana, Miriam; Castro, Azucena; Falcon-Perez, Juan M

    2017-02-15

    Hepatocytes are involved in the endogenous and drug metabolism; many of the enzymes involved in those processes are incorporated into extracellular vesicles and secreted into the bloodstream. Liver-damaging conditions modify the molecular cargo of those vesicles significantly. However, no information about the effect of these hepatic vesicles on the extracellular environment is available. Drug-induced liver damage increases the number of circulating extracellular vesicles and affects the release and content of hepatocyte-derived vesicles. In this work, we evaluated the metabolic effect of these vesicles on the composition of the serum. We performed a targeted ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) metabolomics analysis of serum samples. The samples had been first incubated with hepatic extracellular vesicles from hepatocytes challenged with acetaminophen or diclofenac. The incubation affected the serum levels of 67 metabolites, such as amino acids and different species of lipids. The metabolites included various species of phosphatidylcholines and phosphatidylethanolamines. These compounds are the components of biological membranes; our observations suggest that the vesicles might take part in remodelling and maintenance of the membranes. Alterations in the levels of some other serum metabolites might have deleterious consequences, for example, the tetracosanoic acid with its cardiovascular effects. However, some of the metabolites whose levels were increased, including alpha-linoleic and tauroursodeoxycholic acids, have been reported to have a protective effect. Our targeted metabolomics analysis indicated that the hepatic extracellular vesicles act as nano-metabolic machines supplying the extracellular environment with the means to integrate diverse tissue responses. In conclusion, we show that the hepatic extracellular vesicles are metabolically active and might play a role in the physiopathological response to hepatic insults

  9. Metabolic profiling of urine and blood plasma in rat models of drug addiction on the basis of morphine, methamphetamine, and cocaine-induced conditioned place preference.

    Science.gov (United States)

    Zaitsu, Kei; Miyawaki, Izuru; Bando, Kiyoko; Horie, Hiroshi; Shima, Noriaki; Katagi, Munehiro; Tatsuno, Michiaki; Bamba, Takeshi; Sato, Takako; Ishii, Akira; Tsuchihashi, Hitoshi; Suzuki, Koichi; Fukusaki, Eiichiro

    2014-02-01

    The metabolic profiles of urine and blood plasma in drug-addicted rat models based on morphine (MOR), methamphetamine (MA), and cocaine (COC)-induced conditioned place preference (CPP) were investigated. Rewarding effects induced by each drug were assessed by use of the CPP model. A mass spectrometry (MS)-based metabolomics approach was applied to urine and plasma of MOR, MA, and COC-addicted rats. In total, 57 metabolites in plasma and 70 metabolites in urine were identified by gas chromatography-MS. The metabolomics approach revealed that amounts of some metabolites, including tricarboxylic acid cycle intermediates, significantly changed in the urine of MOR-addicted rats. This result indicated that disruption of energy metabolism is deeply relevant to MOR addiction. In addition, 3-hydroxybutyric acid, L-tryptophan, cystine, and n-propylamine levels were significantly changed in the plasma of MOR-addicted rats. Lactose, spermidine, and stearic acid levels were significantly changed in the urine of MA-addicted rats. Threonine, cystine, and spermidine levels were significantly increased in the plasma of COC-addicted rats. In conclusion, differences in the metabolic profiles were suggestive of different biological states of MOR, MA, and COC addiction; these may be attributed to the different actions of the drugs on the brain reward circuitry and the resulting adaptation. In addition, the results showed possibility of predict the extent of MOR addiction by metabolic profiling. This is the first study to apply metabolomics to CPP models of drug addiction, and we demonstrated that metabolomics can be a multilateral approach to investigating the mechanism of drug addiction.

  10. [Update of recommendations for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Working Group on Osteoporosis and Mineral Metabolism of the Spanish Society of Endocrinology].

    Science.gov (United States)

    Reyes-García, Rebeca; García-Martín, Antonia; Varsavsky, Mariela; Rozas-Moreno, Pedro; Cortés-Berdonces, María; Luque-Fernández, Inés; Gómez Sáez, José Manuel; Vidal Casariego, Alfonso; Romero Muñoz, Manuel; Guadalix Iglesias, Sonsoles; Fernández García, Diego; Jódar Gimeno, Esteban; Muñoz Torres, Manuel

    2015-05-01

    To update previous recommendations developed by the Working Group on Osteoporosis and Mineral Metabolism of the Spanish Society of Endocrinology and Nutrition for the evaluation and treatment of osteoporosis associated to different endocrine and nutritional diseases. Members of the Working Group on Osteoporosis and Mineral Metabolism of the Spanish Society of Endocrinology and Nutrition. Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed) using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date between 18 October 2011 and 30 October 2014 were included. The recommendations were discussed and approved by all members of the Working Group. This update summarizes the new data regarding evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

  11. Glycogen phosphorylase inhibitor N-(3,5-dimethyl-Benzoyl-N'-(β-D-glucopyranosylurea improves glucose tolerance under normoglycemic and diabetic conditions and rearranges hepatic metabolism.

    Directory of Open Access Journals (Sweden)

    Lilla Nagy

    Full Text Available Glycogen phosphorylase (GP catalyzes the breakdown of glycogen and largely contributes to hepatic glucose production making GP inhibition an attractive target to modulate glucose levels in diabetes. Hereby we present the metabolic effects of a novel, potent, glucose-based GP inhibitor (KB228 tested in vitro and in vivo under normoglycemic and diabetic conditions. KB228 administration enhanced glucose sensitivity in chow-fed and obese, diabetic mice that was a result of higher hepatic glucose uptake. Besides improved glucose sensitivity, we have observed further unexpected metabolic rearrangements. KB228 administration increased oxygen consumption that was probably due to the overexpression of uncoupling protein-2 (UCP2 that was observed in animal and cellular models. Furthermore, KB228 treatment induced mammalian target of rapamycin complex 2 (mTORC2 in mice. Our data demonstrate that glucose based GP inhibitors are capable of reducing glucose levels in mice under normo and hyperglycemic conditions. Moreover, these GP inhibitors induce accommodation in addition to GP inhibition--such as enhanced mitochondrial oxidation and mTORC2 signaling--to cope with the glucose influx and increased glycogen deposition in the cells, however the molecular mechanism of accommodation is unexplored.

  12. Pattern of γ-glutamyl transferase activity in cow milk throughout lactation and relationships with metabolic conditions and milk composition.

    Science.gov (United States)

    Calamari, L; Gobbi, L; Russo, F; Cappelli, F Piccioli

    2015-08-01

    The main objective of this experiment was to study the γ-glutamyl transferase (GGT) activity in milk during lactation and its relationship with metabolic status of dairy cows, milk yield, milk composition, and cheesemaking properties. The study was performed in a tied stall barn and involved 20 lactations from 12 healthy multiparous Italian Friesian dairy cows. During lactation starting at d 10, milk samples were collected weekly and analyzed for composition, somatic cells count, titratable acidity, and milk coagulation properties. The GGT activity was measured in defatted samples. Blood samples were collected weekly to assess biochemical indicators related to energy, protein, and mineral metabolism, markers of inflammation and some enzyme activities. The lactations of each cow were retrospectively categorized into 2 groups according to their milk GGT activity value through lactation. A median value of GGT activity in the milk of all lactations was calculated (3,045 U/L), and 10 lactations with lower GGT activity were classified as low while 10 lactations with greater GGT activity were classified as high. The average value of milk GGT activity during lactation was 3,863 and 3,024 U/L for high and low, respectively. The GGT activity decreased in early lactation and reached minimum values in the second month (3,289 and 2,355 U/L for high and low, respectively). Thereafter GGT activity increased progressively, reaching values in late lactation of 4,511 and 3,540 U/L in high and low, respectively. On average, milk yield was 40.81 and 42.76 kg/d in high and low, respectively, and a negative partial correlation with milk GGT activity was observed. A greater milk protein concentration was observed in high (3.39%) compared with low (3.18%), and a positive partial correlation with milk GGT activity was observed. Greater titratable acidity in high than that in low (3.75 vs. 3.45 degrees Soxhlet-Henkel/50 mL, respectively) was also observed. Plasma glucose was greater in

  13. Studies of Aqueous U(IV) Complexation under Thiol-rich Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Wansik; Cho, Hyeryun; Jung, Euo Chang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Organic thiol compounds and hydrogen sulfide (H{sub 2}S) are electron donors and metabolic products of sulfate reducing bacteria. In addition, they are among redox potential (Eh) determinants of groundwater systems due to their redox characteristics. The low values of acid dissociation constants for .SH (pK{sub a}, 7-9) compared to those of aliphatic or phenolic .OH, impart greater anionic and metal-binding properties to the molecules. Recently, we demonstrated that a thiol compound (i. e., thiosalicylate) enhances the solubility of U(VI) at higher pH levels (< ∼9). In this study, to have a better knowledge of the behaviors of U(IV) species under anaerobic conditions, the U(IV)-OH complex formation in the presence of thiol was examined using UV-Vis spectrophotometry and TRLFS (time-resolved laser-induced fluorescence spectroscopy). A TRLFS-based U(IV) quantification methodology developed earlier was applied to examine the effects of thiol species on the dissolution behaviors. Based on UV-Vis absorption monitoring, the presence of thiol does not result in a significant changes in the low-pH hydrolysis behaviors of U(IV). However, the concentration of U(IV) dissolved in bulk phase of aqueous solutions increased with the increase of thiol concentration. The formation of soluble thiol complexes or the stabilization of UO{sub 2} nanoparticles may explain the observed solubility increase.

  14. Social hierarchies, growth and brain serotonin metabolism in Atlantic salmon (Salmo salar) kept under commercial rearing conditions.

    Science.gov (United States)

    Cubitt, K Fiona; Winberg, Svante; Huntingford, Felicity A; Kadri, Sunil; Crampton, Vivian O; Overli, Oyvind

    2008-07-05

    Monitoring social interactions between individuals in large, high-density groups poses several challenges. Here we demonstrate that relative concentrations of serotonin (5-Hydroxytryptamine, 5-HT) and its principal catabolite 5-Hydroxyindoleacetic acid (5-HIAA) in brain tissue of individual fish reflect social organisation in large groups of farmed Atlantic salmon. In the central nervous system of vertebrates, the monoamine neurotransmitter/neuromodulator 5-HT is critical for maintaining adaptive physiological, cognitive and emotional processes. In both teleost fish and mammals it has previously been shown that social interactions in small groups lead to elevated 5-HT release and/or metabolism in subordinate individuals, as indicated by the 5-HIAA/5-HT concentration ratio. In the current study, evidence is presented of non-linear dominance hierarchies in farmed Atlantic salmon (Salmo salar) kept at high rearing densities. The physiological effect of these hierarchies was decreased when food resources were abundant, although some subordinate fish still showed altered brain serotonergic activity and failed to grow even feed was available in excess. The largest effect of decreased feed rations was seen in fish of intermediate size, where competition appeared to increase with reduced access to feed. The largest individuals in each rearing unit showed low 5-HIAA/5-HT ratios independent of feeding regime. A novel observation, with respect to previous studies, was that elevated brain 5-HIAA/5-HT ratios resulted from decreased 5-HT concentrations rather than elevated 5-HIAA in small fish. Thus, in light of the serotonin deficit hypothesis of depression, it cannot be excluded that social stress is important for animal welfare even in large, relatively homogenous groups of animals reared in captivity.

  15. Candidate gene association study conditioning on individual ancestry in patients with type 2 diabetes and metabolic syndrome from Mexico City.

    Science.gov (United States)

    Cruz, M; Valladares-Salgado, A; Garcia-Mena, J; Ross, K; Edwards, M; Angeles-Martinez, J; Ortega-Camarillo, C; de la Peña, J Escobedo; Burguete-Garcia, A I; Wacher-Rodarte, N; Ambriz, R; Rivera, R; D'artote, A L; Peralta, J; Parra, Esteban J; Kumate, J

    2010-05-01

    Type 2 diabetes (T2D) is influenced by diverse environmental and genetic risk factors. Metabolic syndrome (MS) increases the risk of cardiovascular disease and diabetes. We analysed 14 cases of polymorphisms located in 10 candidate loci, in a sample of patients with T2D and controls from Mexico City. We analysed the association of 14 polymorphisms located within 10 genes (TCF7L2, ENPP1, ADRB3, KCNJ11, LEPR, PPARgamma, FTO, CDKAL1, SIRT1 and HHEX) with T2D and MS. The analysis included 519 subjects with T2D defined according to the ADA criteria, 389 with MS defined according to the AHA/NHLBI criteria and 547 controls. Association was tested with the program ADMIXMAP including individual ancestry, age, sex, education and in some cases body mass index (BMI), in a logistic regression model. The two markers located within the TCF7L2 gene showed strong associations with T2D (rs7903146, T allele, odd ratio (OR) = 1.76, p = 0.001 and rs12255372, T allele, OR = 1.78, p = 0.002), but did not show significant association with MS. The non-synonymous rs4994 polymorphism of the ADRB3 gene was associated with T2D (Trp allele, OR = 0.62, p = 0.001) and MS (Trp allele, OR = 0.74, p = 0.018). Nominally significant associations were also observed between T2D and the SIRT1 rs3758391 SNP and MS and the HHEX rs5015480 polymorphism. Variants located within the gene TCF7L2 are strongly associated with T2D but not with MS, providing support to previous evidence indicating that polymorphisms at the TCF7L2 gene increase T2D risk. In contrast, the non-synonymous ADRB3 rs4994 polymorphism is associated with T2D and MS.

  16. NMR and GC-MS Based Metabolic Profiling and Free-Radical Scavenging Activities of Cordyceps pruinosa Mycelia Cultivated under Different Media and Light Conditions

    Science.gov (United States)

    Oh, Taek-Joo; Hyun, Sun-Hee; Lee, Seul-Gi; Chun, Young-Jin; Sung, Gi-Ho; Choi, Hyung-Kyoon

    2014-01-01

    Variation of metabolic profiles in Cordyceps pruinosa mycelia cultivated under various media and light conditions was investigated using 1H nuclear magnetic resonance (NMR) analysis and gas chromatography mass spectrometry (GC-MS) with multivariate statistical analysis. A total of 71 metabolites were identified (5 alcohols, 21 amino acids, 15 organic acids, 4 purines, 3 pyrimidines, 7 sugars, 11 fatty acids, and 5 other metabolites) by NMR and GC-MS analysis. The mycelia grown in nitrogen media and under dark conditions showed the lowest growth and ergosterol levels, essential to a functional fungal cell membrane; these mycelia, however, had the highest levels of putrescine, which is involved in abiotic stress tolerance. In contrast, mycelia cultivated in sabouraud dextrose agar with yeast extract (SDAY) media and under light conditions contained relatively higher levels of fatty acids, including valeric acid, stearic acid, lignoceric acid, myristic acid, oleic acid, palmitoleic acid, hepadecenoic acid, and linoleic acid. These mycelia also had the highest phenolic content and antioxidant activity, and did not exhibit growth retardation due to enhanced asexual development caused by higher levels of linoleic acid. Therefore, we suggested that a light-enriched environment with SDAY media was more optimal than dark condition for cultivation of C. pruinosa mycelia as biopharmaceutical or nutraceutical resources. PMID:24608751

  17. Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

    Science.gov (United States)

    Sperlich, D.; Chang, C. T.; Peñuelas, J.; Gracia, C.; Sabaté, S.

    2014-10-01

    Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (advantage of evergreen species that are able to photosynthesize all year round where a significant fraction can be attributed to winter months, compensates for the lower carbon uptake during spring and summer in comparison to deciduous species. We investigated the ecophysiological behaviour of three co-occurring mature evergreen tree species (Quercus ilex L., Pinus halepensis Mill., and Arbutus unedo L.). Therefore, we collected twigs from the field during a period of mild winter conditions and after a sudden cold period. After both periods, the state of the photosynthetic machinery was tested in the laboratory by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc, max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). The responses of Vc, max and Jmax were highly species specific, with Q. ilex exhibiting the highest and P. halepensis the lowest reductions. In contrast, the optimal fluorometric quantum yield of photosystem II (Fv/Fm) was significantly

  18. Rhamdia quelen (Quoy & Gaimard, 1824, submitted to a stressful condition: effect of dietary addition of the essential oil of Lippia alba on metabolism, osmoregulation and endocrinology

    Directory of Open Access Journals (Sweden)

    Carine de Freitas Souza

    Full Text Available ABSTRACT The aim of this study was to evaluate the effect of the essential oil of Lippia alba (EOLA as a feed additive on ionoregulatory and metabolic parameters and pituitary hormones expression in silver catfish, Rhamdia quelen , submitted to a stressful condition (stocking density of 10.6 kg m-3 and limited space. Fish were fed with different concentrations of EOLA (0.0 - control, 0.25 and 0.50 mL kg food-1 for 20 days. Metabolic parameters were not affected by the diet, with the exception of alanine aminotransferase, which was higher in the liver of fish fed 0.50 mL EOLA kg food-1. Plasma ions and activity of H+-ATPase did not change, but fish fed 0.25 mL EOLA kg food-1 presented higher Na+/K+-ATPase activity. Somatolactin expression in the pituitary was higher in the fish fed 0.25 mL EOLA kg food -1, but the expression of growth hormone and prolactin did not change. Therefore, dietary EOLA does not exert a protective effect in R. quelen submitted to a stressful situation because it did not alter most measured parameters. The use of 0.25 mL EOLA kg food-1 seems to be more suitable than 0.50 mL EOLA kg food-1 since the latter may be related to liver damage.

  19. NTproBNP in insulin-resistance mediated conditions: overweight/obesity, metabolic syndrome and diabetes. The population-based Casale Monferrato Study.

    Science.gov (United States)

    Baldassarre, Stefano; Fragapani, Salvatore; Panero, Antonio; Fedele, Debora; Pinach, Silvia; Lucchiari, Manuela; Vitale, Anna Rita; Mengozzi, Giulio; Gruden, Gabriella; Bruno, Graziella

    2017-09-25

    NTproBNP and BNP levels are reduced in obese subjects, but population-based data comparing the pattern of this relationship in the full spectrum of insulin-resistance mediated conditions, overweight/obesity, metabolic syndrome and diabetes, are limited. The study-base were 3244 individuals aged 45-74 years, none of whom had heart failure, 1880 without diabetes and 1364 with diabetes, identified as part of two surveys of the population-based Casale Monferrato Study. All measurements were centralized. We examined with multiple linear regression and cubic regression splines the relationship between NTproBNP and BMI, independently of known risk factors and confounders. A logistic regression analysis was also performed to assess the effect of overweight/obesity (BMI ≥ 25 kg/m(2)), diabetes and metabolic syndrome on NTproBNP values. Out of the overall cohort of 3244 people, overweight/obesity was observed in 1118 (59.4%) non-diabetic and 917 (67.2%) diabetic subjects, respectively. In logistic regression, compared to normal weight individuals, those with a BMI ≥ 25 kg/m(2) had a OR of 0.70 (95% CI 0.56-0.87) of having high NTproBNP values, independently of diabetes. As interaction between diabetes and NTproBNP was evident (p obesity or metabolic syndrome enhanced fourfold and over the OR of having high NTproBNP levels, while the presence of metabolic syndrome alone had a more modest effect (OR 1.54, 1.18-2.01) even after having excluded individuals with CVD. In the non-diabetic cohort, obesity/overweight and HOMA-IR ≥ 2.0 decreased to a similar extent the ORs of high NTproBNP [0.76 (0.60-0.95) and 0.74 (0.59-0.93)], but the association between overweight/obesity and NTproBNP was no longer significant after the inclusion into the model of HOMA-IR, whereas CRP > 3 mg/dl conferred a fully adjusted OR of 0.65 (0.49-0.86). NT-proBNP levels are lower in overweight/obesity, even in those with diabetes. Both insulin-resistance and chronic low-grade inflammation

  20. Modelling and analysis of central metabolism operating regulatory interactions in salt stress conditions in a L-carnitine overproducing E. coli strain.

    Directory of Open Access Journals (Sweden)

    Guido Santos

    Full Text Available Based on experimental data from E. coli cultures, we have devised a mathematical model in the GMA-power law formalism that describes the central and L-carnitine metabolism in and between two steady states, non-osmotic and hyperosmotic (0.3 M NaCl. A key feature of this model is the introduction of type of kinetic order, the osmotic stress kinetic orders (g(OSn, derived from the power law general formalism, which represent the effect of osmotic stress in each metabolic process of the model.By considering the values of the g(OSn linked to each metabolic process we found that osmotic stress has a positive and determinant influence on the increase in flux in energetic metabolism (glycolysis; L-carnitine biosynthesis production; the transformation/excretion of Acetyl-CoA into acetate and ethanol; the input flux of peptone into the cell; the anabolic use of pyruvate and biomass decomposition. In contrast, we found that although the osmotic stress has an inhibitory effect on the transformation flux from the glycolytic end products (pyruvate to Acetyl-CoA, this inhibition is counteracted by other effects (the increase in pyruvate concentration to the extent that the whole flux increases. In the same vein, the down regulation exerted by osmotic stress on fumarate uptake and its oxidation and the production and export of lactate and pyruvate are reversed by other factors up to the point that the first increased and the second remained unchanged.The model analysis shows that in osmotic conditions the energy and fermentation pathways undergo substantial rearrangement. This is illustrated by the observation that the increase in the fermentation fluxes is not connected with fluxes towards the tricaboxylic acid intermediates and the synthesis of biomass. The osmotic stress associated with these fluxes reflects these changes. All these observations support that the responses to salt stress observed in E. coli might be conserved in halophiles.Flux evolution

  1. Metabolic Syndrome and Migraine

    OpenAIRE

    Amit eSachdev; Michael eMarmura

    2012-01-01

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

  2. Restoration of Impaired Metabolic Energy Balance (ATP Pool and Tube Formation Potential of Endothelial Cells under “high glucose”, Diabetic Conditions by the Bioinorganic Polymer Polyphosphate

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2017-11-01

    Full Text Available Micro-vascularization is a fast, energy-dependent process that is compromised by elevated glucose concentrations such as in diabetes mellitus disease. Here, we studied the effect of the physiological bioinorganic polymer, polyphosphate (polyP, on the reduced ATP content and impaired function of endothelial cells cultivated under “high glucose” (35 mM diabetes mellitus conditions concentrations. This high-energy biopolymer has been shown to provide a source of metabolic energy, stored in its phosphoanhydride bonds. We show that exposure of human umbilical vein endothelial cells (HUVEC cells to “high glucose” levels results in reduced cell viability, increased apoptotic cell death, and a decline in intracellular ATP level. As a consequence, the ability of HUVEC cells to form tube-like structures in the in vitro cell tube formation assay was almost completely abolished under “high glucose” conditions. Those cells were grown onto a physiological collagen scaffold (collagen/basement membrane extract. We demonstrate that these adverse effects of increased glucose levels can be reversed by administration of polyP to almost normal values. Using Na-polyP, complexed in a stoichiometric (molar ratio to Ca2+ ions and in the physiological concentration range between 30 and 300 µM, an almost complete restoration of the reduced ATP pool of cells exposed to “high glucose” was found, as well as a normalization of the number of apoptotic cells and energy-dependent tube formation. It is concluded that the adverse effects on endothelial cells caused by the metabolic energy imbalance at elevated glucose concentrations can be counterbalanced by polyP, potentially opening new strategies for treatment of the micro-vascular complications in diabetic patients.

  3. Impaired quality of life in growth hormone-deficient adults is independent of the altered skeletal muscle oxidative metabolism found in conditions with peripheral fatigue.

    Science.gov (United States)

    Sinha, Akash; Hollingsworth, Kieren G; Ball, Steve; Cheetham, Tim

    2014-01-01

    Growth hormone-deficient (GHD) adults often report impaired quality of life (QoL) - with fatigue, a key element. This deficit can improve following GH replacement. The basis of this response is unclear. Perturbations in skeletal muscle metabolism have been demonstrated in several conditions in which fatigue is a prominent symptom. We wished to define the role of skeletal muscle metabolism in the impaired QoL observed in patients with GHD. To compare in vivo skeletal muscle mitochondrial oxidative phosphorylation using phosphorus-31 magnetic resonance spectroscopy in matched untreated GHD adults, treated GHD adults and healthy volunteers. Twenty-two untreated GHD adults, 23 treated GHD adults and 20 healthy volunteers were recruited at a regional centre. All patients underwent assessment of muscle mitochondrial function (τ₁/₂ PCr) and proton handling using spectroscopy. Fasting biochemical analyses and anthropometric measurement were obtained. All patients completed the QoL-AGHDA and physical activity assessment (IPAQ) questionnaires. Untreated and treated GHD adults complained of significantly increased fatigue and an impaired QoL (P = 0·002) when compared to healthy controls. There was no difference in maximal mitochondrial function (P = 0·53) nor pH recovery (P = 0·38) of skeletal muscle between the three groups. Untreated GHD patients had significantly lower IGF-1 than both treated GHD and healthy volunteers (P muscle spectroscopic 'footprint' of altered mitochondrial oxidative function, anaerobic glycolysis or proton clearance that are a feature of several conditions in which fatigue is a prominent feature. These data suggest that the pathophysiology of fatigue and impaired QoL in GHD may have a significant central rather than peripheral (skeletal muscle) component. © 2013 John Wiley & Sons Ltd.

  4. System-Wide Adaptations of Desulfovibrio alaskensis G20 to Phosphate-Limited Conditions.

    Directory of Open Access Journals (Sweden)

    Tanja Bosak

    Full Text Available The prevalence of lipids devoid of phosphorus suggests that the availability of phosphorus limits microbial growth and activity in many anoxic, stratified environments. To better understand the response of anaerobic bacteria to phosphate limitation and starvation, this study combines microscopic and lipid analyses with the measurements of fitness of pooled barcoded transposon mutants of the model sulfate reducing bacterium Desulfovibrio alaskensis G20. Phosphate-limited G20 has lower growth rates and replaces more than 90% of its membrane phospholipids by a mixture of monoglycosyl diacylglycerol (MGDG, glycuronic acid diacylglycerol (GADG and ornithine lipids, lacks polyphosphate granules, and synthesizes other cellular inclusions. Analyses of pooled and individual mutants reveal the importance of the high-affinity phosphate transport system (the Pst system, PhoR, and glycolipid and ornithine lipid synthases during phosphate limitation. The phosphate-dependent synthesis of MGDG in G20 and the widespread occurrence of the MGDG/GADG synthase among sulfate reducing ∂-Proteobacteria implicate these microbes in the production of abundant MGDG in anaerobic environments where the concentrations of phosphate are lower than 10 μM. Numerous predicted changes in the composition of the cell envelope and systems involved in transport, maintenance of cytoplasmic redox potential, central metabolism and regulatory pathways also suggest an impact of phosphate limitation on the susceptibility of sulfate reducing bacteria to other anthropogenic or environmental stresses.

  5. Kinetics of organic transformations under mild aqueous conditions: implications for the origin of life and its metabolism

    Science.gov (United States)

    Weber, Arthur L.

    2004-01-01

    The rates of thermal transformation of organic molecules containing carbon, hydrogen, and oxygen were systematically examined in order to identify the kinetic constraints that governed origin-of-life organic chemistry under mild aqueous conditions. Arrhenius plots of the kinetic data were used to estimate the reaction of half-lifes at 50 degrees C. This survey showed that hydrocarbons and organic substances containing a single oxygenated group were kinetically the most stable; whereas organic substances containing two oxygenated groups in which one group was an alpha- or beta-positioned carbonyl group were the most reactive. Compounds with an alpha- or beta-positioned carbonyl group (aldehyde or ketone) had rates of reaction that were up to 10(24)-times faster than rates of similar molecules lacking the carbonyl group. This survey of organic reactivity, together with estimates of the molecular containment properties of lipid vesicles and liquid spherules, indicates that an origins process in a small domain that used C,H,O-intermediates had to be catalytic and use the most reactive organic molecules to prevent escape of its reaction intermediates.

  6. Effects of chromium and chromium + vitamin C combination on metabolic, oxidative, and fear responses of broilers transported under summer conditions

    Science.gov (United States)

    Perai, A. H.; Kermanshahi, H.; Moghaddam, H. Nassiri; Zarban, A.

    2015-04-01

    A total of 240 female broilers (42 days old) were randomly assigned to four groups with six replicates and fed either a basal diet (two control groups) or a basal diet supplemented with either 1,200 μg Cr+3 from chromium (Cr) methionine/kg (Cr group) or 1,200 μg Cr+3 from Cr methionine plus 800 mg vitamin C (Vit C)/kg of diet (Cr + Vit C group). After 7 days on the dietary treatment, all groups except one of the controls were transported for 3 h under the summer conditions. Performance parameters were not influenced by dietary treatments. The plasma concentrations of insulin, triiodothyronine, triglyceride, and the ratio of triiodothyronine/thyroxin were decreased and the ratio of glucose/insulin was increased due to transport process. Road transportation also increased the plasma concentrations of protein, cholesterol, aspartate aminotransferase, and creatine kinase and decreased the concentration of low-density lipoprotein cholesterol in the Cr + Vit C group. The pretransport concentrations of insulin and triiodothyronine were highest in the Cr + Vit C group. The concentration of phosphorous was lower in the Cr group than that in the other groups after transport. No significant effects of dietary treatments were observed on the other biochemical parameters. Transport increased malondialdehyde concentration in the control group and did not change plasma total antioxidant capacity and erythrocyte glutathione peroxidase activity. Either in combination or alone, Cr increased plasma total antioxidant capacity (before transport P ≤ 0.05, after transport P = 0.07) but did not affect the concentration of malondialdehyde and activity of glutathione peroxidase. The duration of tonic immobility (TI) was similar between nontransported control chicks and transported chicks without any supplements. Pretreatment with Cr + Vit C significantly reduced the duration of TI.

  7. Metabolism and antioxidant defense in the larval chironomid Tanytarsus minutipalpus: adjustments to diel variations in the extreme conditions of Lake Magadi

    Directory of Open Access Journals (Sweden)

    Lucas F. Bianchini

    2017-01-01

    Full Text Available Insect larvae are reported to be a major component of the simple but highly productive trophic web found in Lake Magadi (Kenya, Africa, which is considered to be one of the most extreme aquatic environments on Earth. Previous studies show that fish must display biochemical and physiological adjustments to thrive under the extreme conditions of the lake. However, information for invertebrates is lacking. In the present study, the occurrence of the larval chironomid Tanytarsus minutipalpus is reported in Lake Magadi for the first time. Additionally, changes in larval metabolism and antioxidant defense correlated with diel variations in the extremely hostile environmental conditions of the lake are described. Wide variations in water temperature (20.2-29.3°C and dissolved oxygen content (3.2-18.6 mg O2 l−1 were observed at different times of day, without significant change in water pH (10.0±0.03. Temperature and dissolved oxygen were higher at 13:00 h (29.3±0.4°C and 18.6±1.0 mg O2 l−1 and 19:00 h (29.3±0.8°C and 16.2±1.6 mg O2 l−1 and lower at 01:00 h (21.1±0.1°C and 10.7±0.03 mg O2 l−1 and 07:00 h (20.2±0.4°C and 3.2±0.7 mg O2 l−1. Significant and parallel increases in parameters related to metabolism (cholinesterase, glucose, cholesterol, urea, creatinine and hemoglobin and the antioxidant system (SOD, GPx, GR, GSH and GSSG were observed in larvae collected at 13:00 h. In contrast, no significant changes were observed in pro-oxidants (ROS and NO, TOSC and oxidative damage parameters (LPO and DNA damage. Therefore, the observed increases in temperature and dissolved O2 content in Lake Magadi were associated with changes in the antioxidant system of T. minutipalpus larvae. Adjustments performed by the chironomid larvae were efficient in maintaining body homeostasis, as well as protecting biomolecules against oxidative damage, so that oxidative stress did not occur. GSH-GSSG and GPx-GR systems appeared to

  8. Dynamics of indicators of a metabolic exchange and condition of blood circulation of the bottom extremities after traction extension at patients with lumbar and sacral dorsopathy

    Directory of Open Access Journals (Sweden)

    Kotenko К.V.

    2013-12-01

    Full Text Available Aim: to study influence of traction therapy in a pulse mode in a complex with electrotherapy on a condition of blood circulation of the bottom extremities and level of a metabolic exchange. Material and methods. There had been examined 120 patients with a lumbar and sacral dorsopathy aged from 22 to 69 years (middle age of 49,5 years with prescription of a disease from 1 to 5 years, among them men of 34,2%, women of 65,8%. Results. The analysis of effects of various medical methods on a condition of local blood circulation in the bottom extremities showed that the most expressed its compensation is noted at complex application of mechanical pulse traction influence and electrotherapy for patients with a dorsopathy of lumbar and sacral department of a backbone that is confirmed by restoration to normal values of all indicators rheovasogramm. Conclusion. High clinical results of application of the combined medical and rehabilitation complex are based on compensation of local blood circulation that is shown in elimination of deficiency of blood supply due to improvement of a tone of arterial vessels and elimination of venous stagnation, and also due to increase of linear speed of a blood-groove and development of collateral blood circulation. Application of electrical impulse and mechanical traction influences, more at their combination promotes fermentative activity of the systems responsible for a protein exchange that is important for prevention of degenerate and dystrophic process progressing.

  9. Purine metabolism in response to hypoxic conditions associated with breath-hold diving and exercise in erythrocytes and plasma from bottlenose dolphins (Tursiops truncatus).

    Science.gov (United States)

    Del Castillo Velasco-Martínez, Iris; Hernández-Camacho, Claudia J; Méndez-Rodríguez, Lía C; Zenteno-Savín, Tania

    2016-01-01

    In mammalian tissues under hypoxic conditions, ATP degradation results in accumulation of purine metabolites. During exercise, muscle energetic demand increases and oxygen consumption can exceed its supply. During breath-hold diving, oxygen supply is reduced and, although oxygen utilization is regulated by bradycardia (low heart rate) and peripheral vasoconstriction, tissues with low blood flow (ischemia) may become hypoxic. The goal of this study was to evaluate potential differences in the circulating levels of purine metabolism components between diving and exercise in bottlenose dolphins (Tursiops truncatus). Blood samples were taken from captive dolphins following a swimming routine (n=8) and after a 2min dive (n=8). Activity of enzymes involved in purine metabolism (hypoxanthine guanine phosphoribosyl transferase (HGPRT), inosine monophosphate deshydrogenase (IMPDH), xanthine oxidase (XO), purine nucleoside phosphorylase (PNP)), and purine metabolite (hypoxanthine (HX), xanthine (X), uric acid (UA), inosine monophosphate (IMP), inosine, nicotinamide adenine dinucleotide (NAD(+)), adenosine, adenosine monophosphate (AMP), adenosine diphosphate (ADP), ATP, guanosine diphosphate (GDP), guanosine triphosphate (GTP)) concentrations were quantified in erythrocyte and plasma samples. Enzymatic activity and purine metabolite concentrations involved in purine synthesis and degradation, were not significantly different between diving and exercise. Plasma adenosine concentration was higher after diving than exercise (p=0.03); this may be related to dive-induced ischemia. In erythrocytes, HGPRT activity was higher after diving than exercise (p=0.007), suggesting an increased capacity for purine recycling and ATP synthesis from IMP in ischemic tissues of bottlenose dolphins during diving. Purine recycling and physiological adaptations may maintain the ATP concentrations in bottlenose dolphins after diving and exercise. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Indicadores metabólicos en razas lecheras especializadas en condiciones tropicales en Colombia Metabolic profile in dairy cows under tropical conditions in Colombia

    Directory of Open Access Journals (Sweden)

    Rómulo Campos G

    2007-06-01

    Full Text Available Se ha seleccionado un alto número de razas bovinas para producción de leche, sin embargo, las de origen Bos taurus no han logrado adaptarse a las condiciones tropicales. El objetivo del trabajo fue analizar el comportamiento metabólico de siete razas (Ayrshire, Girolando, Holstein Friesian, Jersey, Lucerna, Pardo Suizo y Simenthal a través de 15 metabolitos. Se emplearon 28 animales por raza, distribuidos en cuatro grupos fisiológicos: novillas, inicio y final de lactancia y vacas secas (final de gestación. Los valores medios de los indicadores metabólicos fueron: BOH 0.5 mmol/l; glucosa 2.8 mmol/l; colesterol 2.5 mmol/l; potasio 4.1 mmol/l; calcio 2.0 mmol/l; fósforo inorgánico 1.7 mmol/l; magnesio 1.1 mmol/l; proteínas totales 66.2 mg/dl; albúmina 25.8 mg/dl; globulinas 40.2 mg/dl; creatinina 109 µmol/l; BUN 3.8 mmol/l; ALT 32.2 UI/l; AST 56.6 UI/l; GGT 12.3 UI/l; bilirrubina total 0.2 µmol/l; bilirrubina conjugada 0.08 µmol/l. Los valores medios de la condición corporal y el hematocrito fueron 3.25% y 27.0% respectivamente. Se encontraron diferencias estadísticas significativas entre grupos raciales y entre grupos de producción. Los animales de menor peso metabólico (Jersey presentaron mejor homeostasis que los de pesos mayores (Simenthal, Holstein.High numbers of bovine breeds have been selected as milk producers, but those derived from the Bos taurus breeds have been unable to adapt to tropical conditions. The aim of this work was to analyze the metabolic profile of the seven breeds (Ayrshire, Girolando, Holstein Friesian, Jersey , Lucerna, Brown Swiss and Simmental through the use of 15 metabolites. For each breed, 28 animals were used, divided into four physiological different groups: heifers, cows from the first stages and last stages of the lactation process and dry cows. The mean values of metabolites indicators were as follow: BOH 0.5 mmol/l; glucose 2.8 mmol/l; cholesterol 2.5 mmol/l; potassium 4.1 mmol/l; calcium 2

  11. Metabolic and transcriptomic response of the wine yeast Saccharomyces cerevisiae strain EC1118 after an oxygen impulse under carbon-sufficient, nitrogen-limited fermentative conditions.

    Science.gov (United States)

    Orellana, Marcelo; Aceituno, Felipe F; Slater, Alex W; Almonacid, Leonardo I; Melo, Francisco; Agosin, Eduardo

    2014-05-01

    During alcoholic fermentation, Saccharomyces cerevisiae is exposed to continuously changing environmental conditions, such as decreasing sugar and increasing ethanol concentrations. Oxygen, a critical nutrient to avoid stuck and sluggish fermentations, is only discretely available throughout the process after pump-over operation. In this work, we studied the physiological response of the wine yeast S. cerevisiae strain EC1118 to a sudden increase in dissolved oxygen, simulating pump-over operation. With this aim, an impulse of dissolved oxygen was added to carbon-sufficient, nitrogen-limited anaerobic continuous cultures. Results showed that genes related to mitochondrial respiration, ergosterol biosynthesis, and oxidative stress, among other metabolic pathways, were induced after the oxygen impulse. On the other hand, mannoprotein coding genes were repressed. The changes in the expression of these genes are coordinated responses that share common elements at the level of transcriptional regulation. Beneficial and detrimental effects of these physiological processes on wine quality highlight the dual role of oxygen in 'making or breaking wines'. These findings will facilitate the development of oxygen addition strategies to optimize yeast performance in industrial fermentations. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. Decontamination of acid mine water from Ronneburg/Thueringen which is high in sulfates and metals using sulfate-reducing bacteria. Pt. 2. Biological bases. Final report of the preliminary phase; Mikrobiologisches Verfahren zur Reinigung radioaktiv und chemisch belasteter Waesser des Sanierungsgebietes Ronneburg. T. 2. Biologische Grundlagen. Abschlussbericht zur Vorphase

    Energy Technology Data Exchange (ETDEWEB)

    Hard, B.; Friedrich, S.

    1995-07-25

    The mining in Eastern Europe, particularly in East-Germany, is a major source of pollution to the surrounding areas of the mines. With the end of the cold war the demand for uranium has drastically declined. Many of the pits have therefore been closed down or are in the process of closure such as the uranium mine in Ronneburg in Thueringen. One major problem is the safe-making of the pits and dumps as they are highly radioactive through naturally occurring uranium and other radioactive elements. Because of the leaching process through bacteria, drainage water is very acidic, with pH-values between 1-2. The water is very rich in magnesium, iron and aluminium sulfate. Here the application of a microbial process to decontaminate acid mine drainage was investigated. Decontamination of the water includes: - Increase in pH - decrease in sulfate concentrations - minimization of the metal and radionuclide load. Sulfate-reducing bacteria seem suitable for this process. In order for such a microbial process to be economically viable a cheap and widely available electron donar has to be used eg. methanol. The work carried out reports on the isolation, characterization and physiology of sulfate-reducing methylotrophic bacteria and their suitability for a decontamination process of sulfuric acid uranium mine water. (orig.) [Deutsch] Ziel der Untersuchungen war, die Moeglichkeit der mikrobiellen Behandlung der Sickerwaesser (stark sauer, radionuklidhaltig, hoher Sulfat- und Metallgehalt) des Sanierungsgebietes Ronneburg zu pruefen. Die mikrobiologische Behandlung soll folgende Problemloesungen liefern: - Reduzierung des Sulfatgehaltes durch sulfatreduzierende Mikroorganismen, - Senkung des Schwermetallgehaltes durch die Faellung als Sulfide, - Abtrennung der Radionuklide durch Faellung, Reduktion, Biosorption oder Akkumulation, - pH-Wert-Verschiebung in den neutralen pH-Bereich waehrend der Sulfatreduktion. In orientierenden Versuchen konnte nachgewiesen werden, dass das

  13. Top-down and bottom-up lipidomic analysis of rabbit lipoproteins under different metabolic conditions using flow field-flow fractionation, nanoflow liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Byeon, Seul Kee; Kim, Jin Yong; Lee, Ju Yong; Chung, Bong Chul; Seo, Hong Seog; Moon, Myeong Hee

    2015-07-31

    This study demonstrated the performances of top-down and bottom-up approaches in lipidomic analysis of lipoproteins from rabbits raised under different metabolic conditions: healthy controls, carrageenan-induced inflammation, dehydration, high cholesterol (HC) diet, and highest cholesterol diet with inflammation (HCI). In the bottom-up approach, the high density lipoproteins (HDL) and the low density lipoproteins (LDL) were size-sorted and collected on a semi-preparative scale using a multiplexed hollow fiber flow field-flow fractionation (MxHF5), followed by nanoflow liquid chromatography-ESI-MS/MS (nLC-ESI-MS/MS) analysis of the lipids extracted from each lipoprotein fraction. In the top-down method, size-fractionated lipoproteins were directly infused to MS for quantitative analysis of targeted lipids using chip-type asymmetrical flow field-flow fractionation-electrospray ionization-tandem mass spectrometry (cAF4-ESI-MS/MS) in selected reaction monitoring (SRM) mode. The comprehensive bottom-up analysis yielded 122 and 104 lipids from HDL and LDL, respectively. Rabbits within the HC and HCI groups had lipid patterns that contrasted most substantially from those of controls, suggesting that HC diet significantly alters the lipid composition of lipoproteins. Among the identified lipids, 20 lipid species that exhibited large differences (>10-fold) were selected as targets for the top-down quantitative analysis in order to compare the results with those from the bottom-up method. Statistical comparison of the results from the two methods revealed that the results were not significantly different for most of the selected species, except for those species with only small differences in concentration between groups. The current study demonstrated that top-down lipid analysis using cAF4-ESI-MS/MS is a powerful high-speed analytical platform for targeted lipidomic analysis that does not require the extraction of lipids from blood samples. Copyright © 2015 Elsevier B

  14. A possible association between space weather conditions and the risk of acute coronary syndrome in patients with diabetes and the metabolic syndrome

    Science.gov (United States)

    Vencloviene, Jone; Babarskiene, Ruta Marija; Kiznys, Deivydas

    2017-01-01

    Hyperglycemia negatively affects cardiovascular variables that are also adversely affected by increased geomagnetic activity. It is likely that geomagnetic storms (GS) could have a stronger negative impact on these patients. We analyzed data on 1548 randomly selected patients with acute coronary syndrome (ACS) who were admitted inpatient treatment in Kaunas city, during 2000-2003. We evaluated the associations of GS, solar proton events (SPE), and high-speed solar wind (HSSW) (solar wind speed ≥600 km/s) with the risk of ACS in patients with diabetes mellitus (DM) and the metabolic syndrome (MS) by using logistic regression with categorical predictors. During days of HSSW, the risk of ACS in DM patients increased by 1.95 times (OR = 1.95, 95 % CI 1.36-2.79) as compared to days without either of these events or 2 days prior to or after them. In the multivariate model, the risk of ACS in DM patients was associated with days of HSSW and 1-2 days after (OR = 1.40, 95 % CI 1.01-1.93), with days of GS lasting >1 day and occurring on days of HSSW or 1-2 days after (OR = 2.31, 95 % CI 1.28-4.17), and with the onset of SPE (OR = 2.72 (1.09-6.83)). The risk of ACS in MS patients was associated with days of GS and 1-2 days prior or after GS (OR = 1.31 (1.00-1.73)); an additional impact was established if these days coincided with days of HSSW or 1-2 days before (OR = 2.16 (1.39-3.35)). These findings suggest that not only GS but also HSSW and changes in space weather conditions prior to SPE affect the human cardiovascular system.

  15. Mercury and lead tolerance in hypersaline sulfate-reducing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Harithsa, S.; Kerkar, S.; LokaBharathi, P.A.

    found to be widely distributed in the marine and estuarine environments (Sanzgiry et al., 1988; George, 1988). Studies on metal microbe interactions are generally restrictedtoaerobicbacteria(Foster,1983;Aikingetal., 1985),anaerobicconsortia...(WhiteandGadd,1996)and sometimes to mesophilic SRB(Loka Bharathi et al., 1990).Thepresentworkhasexaminedtheinteractionof a few hypersaline isolates of SRBwith Hg and Pb at elevated concentrations of the metal salts, as saltpans * Corresponding author. Tel.: +91...

  16. Microbial corrosion of carbon steel by sulfate-reducing bacteria:

    DEFF Research Database (Denmark)

    Nielsen, Lars Vendelbo; Hilbert, Lisbeth Rischel

    1997-01-01

    Electrochemical measurements (EIS and DC-polarisation curves) have been conducted on carbon steel coupons exposed in SRB-active environments. Results from EIS measurements show that very large interfacial capacities are found in such systems, and consequently high capacitive currents are to be ex...

  17. Deciphering the prokaryotic community and metabolisms in South African deep-mine biofilms through antibody microarrays and graph theory.

    Directory of Open Access Journals (Sweden)

    Yolanda Blanco

    Full Text Available In the South African deep mines, a variety of biofilms growing in mine corridor walls as water seeps from intersections or from fractures represents excellent proxies for deep-subsurface environments. However, they may be greatly affected by the oxygen inputs through the galleries of mining activities. As a consequence, the interaction between the anaerobic water coming out from the walls with the oxygen inputs creates new conditions that support rich microbial communities. The inherent difficulties for sampling these delicate habitats, together with transport and storage conditions may alter the community features and composition. Therefore, the development of in situ monitoring methods would be desirable for quick evaluation of the microbial community. In this work, we report the usefulness of an antibody-microarray (EMChip66 immunoassay for a quick check of the microbial diversity of biofilms located at 1.3 km below surface within the Beatrix deep gold mine (South Africa. In addition, a deconvolution method, previously described and used for environmental monitoring, based on graph theory and applied on antibody cross-reactivity was used to interpret the immunoassay results. The results were corroborated and further expanded by 16S rRNA gene sequencing analysis. Both culture-independent techniques coincided in detecting features related to aerobic sulfur-oxidizers, aerobic chemoorganotrophic Alphaproteobacteria and metanotrophic Gammaproteobacteria. 16S rRNA gene sequencing detected phylotypes related to nitrate-reducers and anaerobic sulfur-oxidizers, whereas the EMChip66 detected immunological features from methanogens and sulfate-reducers. The results reveal a diverse microbial community with syntrophic metabolisms both anaerobic (fermentation, methanogenesis, sulphate and nitrate reduction and aerobic (methanotrophy, sulphur oxidation. The presence of oxygen-scavenging microbes might indicate that the system is modified by the artificial

  18. Proteomic approaches for the study of tissue specific effects of 3,5,3’-triiodo-L-thyronine and 3,5-diiodo-L-thyronine in conditions of altered energy metabolism.

    Directory of Open Access Journals (Sweden)

    Elena eSilvestri

    2014-12-01

    Full Text Available In vertebrates and, specifically, in mammals, energy homeostasis is achieved by the integration of metabolic and neuroendocrine signals linked to one another in an intricate network hierarchically responding to the tight modulating action of hormones among which thyroid hormones (THs play a central role. At the cellular level, 3,5,3’-triiodo-L-thyronine (T3 acts mainly by binding to specific nuclear receptors (TRs but actually it is becoming more and more evident that some T3- actions are independent of TRs and that other iodothyronines, such as 3,5-diiodo-L-thyronine (T2, affect energy metabolism and adiposity. In the postgenomic era, clinical and basic biological researches are increasingly benefiting from the recently developed new omics approaches including, among the others, proteomics. Considering the recognized value of proteins as excellent targets in physiology, the functional and simultaneous analysis of the expression level and the cellular localization of multiple proteins can actually be considered fundamental in the understanding of complex mechanisms such as those involved in thyroid control of metabolism. Here, we will discuss new leads (i.e. target proteins and metabolic pathways emerging in applying proteomics to the actions of T3 and T2 in conditions of altered energy metabolism in animal tissues having a central role in the control of energy balance.

  19. Proteomic approaches for the study of tissue specific effects of 3,5,3'-triiodo-L-thyronine and 3,5-diiodo-L-thyronine in conditions of altered energy metabolism.

    Science.gov (United States)

    Silvestri, Elena; Coppola, Maria; Cioffi, Federica; Goglia, Fernando

    2014-01-01

    In vertebrates and, specifically, in mammals, energy homeostasis is achieved by the integration of metabolic and neuroendocrine signals linked to one another in an intricate network hierarchically responding to the tight modulating action of hormones among which thyroid hormones (THs) play a central role. At the cellular level, 3,5,3'-triiodo-L-thyronine (T3) acts mainly by binding to specific nuclear receptors (TRs) but actually it is becoming more and more evident that some T3- actions are independent of TRs and that other iodothyronines, such as 3,5-diiodo-L-thyronine (T2), affect energy metabolism and adiposity. In the postgenomic era, clinical and basic biological researches are increasingly benefiting from the recently developed new omics approaches including, among the others, proteomics. Considering the recognized value of proteins as excellent targets in physiology, the functional and simultaneous analysis of the expression level and the cellular localization of multiple proteins can actually be considered fundamental in the understanding of complex mechanisms such as those involved in thyroid control of metabolism. Here, we will discuss new leads (i.e., target proteins and metabolic pathways) emerging in applying proteomics to the actions of T3 and T2 in conditions of altered energy metabolism in animal tissues having a central role in the control of energy balance.

  20. Metabolic syndrome and migraine

    Directory of Open Access Journals (Sweden)

    Amit eSachdev

    2012-11-01

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

  1. Metabolic syndrome and migraine.

    Science.gov (United States)

    Sachdev, Amit; Marmura, Michael J

    2012-01-01

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

  2. Treatment of Amino Acid Metabolism Disorders

    Science.gov (United States)

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

  3. Central metabolism in Mycobacterium smegmatis during the transition from O2-rich to O2-poor conditions as studied by isotopomer-assisted metabolite analysis.

    Science.gov (United States)

    Tang, Yinjie J; Shui, Wenqing; Myers, Samuel; Feng, Xueyang; Bertozzi, Carolyn; Keasling, Jay D

    2009-08-01

    Isotopomer-assisted metabolite analysis was used to investigate the central metabolism of Mycobacterium smegmatis and its transition from normal growth to a non-replicating state under a hypoxic environment. Tween 80 significantly promoted aerobic growth by improving O(2) transfer, while only small amount was degraded and metabolized via the TCA cycle for biomass synthesis. As the bacillus encountered hypoxic stress, isotopomer analysis suggested: (1) isocitrate lyase activity increased, which further induced glyoxylate pathway and glycine dehydrogenase for replenishing NAD(+); (2) the relative amount of acetyl-CoA entering the TCA cycle was doubled, whereas little entered the glycolytic and pentose phosphate pathways.

  4. Imprint of past and present environmental conditions on microbiology and biogeochemistry of coastal Quaternary sediments

    Directory of Open Access Journals (Sweden)

    M. Beck

    2011-01-01

    Full Text Available To date, North Sea tidal-flat sediments have been intensively studied down to a depth of 5 m below seafloor (mbsf. However, little is known about the biogeochemistry, microbial abundance, and activity of sulfate reducers as well as methanogens in deeper layers. In this study, two 20 m-long cores were retrieved from the tidal-flat area of Spiekeroog Island, NW Germany. The drill sites were selected with a close distance of 900 m allowing to compare two depositional settings: first, a paleo-channel filled with Holocene sediments and second, a mainly Pleistocene sedimentary succession. Analyzing these cores, we wanted to test to which degree the paleo-environmental imprint is superimposed by present processes.

    In general, the numbers of bacterial 16S rRNA genes are one to two orders of magnitude higher than those of Archaea. The abundances of key genes for sulfate reduction and methanogenesis (dsrA and mcrA correspond to the sulfate and methane profiles. A co-variance of these key genes at sulfate-methane interfaces and enhanced ex situ AOM rates suggest that anaerobic oxidation of methane may occur in these layers. Microbial and biogeochemical profiles are vertically stretched relative to 5 m-deep cores from shallower sediments in the same study area, but still appear compressed compared to deep sea sediments. Our interdisciplinary analysis shows that the microbial abundances and metabolic rates are elevated in the Holocene compared to Pleistocene sediments. However, this is mainly due to present environmental conditions such as pore water flow and organic matter availability. The paleo-environmental imprint is still visible but superimposed by these processes.

  5. Metabolic fates and effects of nitrite in brown trout under normoxic and hypoxic conditions: blood and tissue nitrite metabolism and interactions with branchial NOS, Na+/K+-ATPase and hsp70 expression

    DEFF Research Database (Denmark)

    Jensen, Frank Bo; Gerber, Lucie; Hansen, Marie Niemann

    2015-01-01

    Nitrite secures essential nitric oxide (NO) bioavailability in hypoxia at low endogenous concentrations, whereas it becomes toxic at high concentrations. We exposed brown trout to normoxic and hypoxic water in the absence and presence of added ambient nitrite to decipher the cellular metabolism...... and effects of nitrite at basal and elevated concentrations under different oxygen regimes. We also tested hypotheses concerning the influence of nitrite on branchial nitric oxide synthase (NOS), Na+/K+-ATPase (nka) and heat shock protein (hsp70) mRNA expression. Basal plasma and erythrocyte nitrite levels...... were higher in hypoxia than normoxia, suggesting increased NOS activity. Nitrite exposure strongly elevated nitrite concentrations in plasma, erythrocytes, heart tissue and white muscle, which was associated with an extensive metabolism of nitrite to nitrate and to iron-nitrosylated and S...

  6. Feeding conditions control the expression of genes involved in sterol metabolism in peripheral blood mononuclear cells of normoweight and diet-induced (cafeteria) obese rats

    NARCIS (Netherlands)

    Caimari, A.; Oliver, P.; Rodenburg, W.; Keijer, J.; Palou, A.

    2010-01-01

    Peripheral blood mononuclear cells (PBMC) are easily obtainable cells from blood whose gene expression profiles have been proven to be highly robust in distinguishing a disease state from healthy state. Sterol metabolism is of physiological importance, and although its nutritional response in liver

  7. Effect of dietary protein levels on rumen metabolism and milk yield in mid-lactating cows under hot and humid conditions

    NARCIS (Netherlands)

    Thiangtum, W.; Schonewille, J.T.; Yawongsa, A.; Rukkwamsuk, T.; Kanjanapruthipong, J.; Verstegen, M.W.A.; Hendriks, W.H.

    2014-01-01

    An experiment was conducted to investigate the effects of 2 levels of dietary Crude Protein (CP) in concentrates with similar proportions of Rumen Undegradable Protein (RUP) on rumen metabolism, milk yield and composition in mid lactating cows in Thailand. Eight 87.5% Holsteinx12.5% indigenous

  8. Effect of dietary protein levels on rumen metabolism and milk yield in mid-lactating cows under hot and humid conditions.

    NARCIS (Netherlands)

    Thiangtum, W; Schonewille, Thomas; Yawongsa, A; Rukkwamsuk, T; Kanjanapruthipon, J; Verstegen, M.W.A.; Hendriks, Wouter

    2014-01-01

    An experiment was conducted to investigate the effects of 2 levels of dietary Crude Protein (CP) in concentrates with similar proportions of Rumen Undegradable Protein (RUP) on rumen metabolism, milk yield and composition in mid lactating cows in Thailand. Eight 87.5% Holsteinx12.5% indigenous

  9. Metabolic Panel

    Science.gov (United States)

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

  10. Metabolic acidosis

    Science.gov (United States)

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

  11. Metabolic neuropathies

    Science.gov (United States)

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

  12. Metabolic flexibility

    National Research Council Canada - National Science Library

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

    2004-01-01

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

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

    National Research Council Canada - National Science Library

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

    2014-01-01

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

  14. Mathematical modelling of metabolism

    DEFF Research Database (Denmark)

    Gombert, Andreas Karoly; Nielsen, Jens

    2000-01-01

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

  15. [The specific features of the development of metabolic and regenerative processes under the action of low-intensity electromagnetic radiation in radiation exposure conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Yu N; Mihajlik, L V; Nikulina, L A; Geniatulina, M S

    2017-01-01

    The experiments on male white rats with the use of biochemical, photo-optical, and electron-microscopic techniques have demonstrated that the use of low-intensity electromagnetic radiation of ultrahigh frequency (EMR UHF) and low-intensity low-frequency magnetic field (MF) during the post-irradiation period (within 21 days after exposure to radiation) enhanced the metabolic and regenerative processes in the testes and liver. It was shown that the application of MF largely intensified the antioxidant activity whereas EMR UHF preferentially stimulated the biosynthetic processes as well as the processes of cellular and intracellular regeneration.

  16. Northern fowl mite (Ornithonyssus sylviarum) effects on metabolism, body temperatures, skin condition, and egg production as a function of hen MHC haplotype.

    Science.gov (United States)

    Murillo, Amy C; Chappell, Mark A; Owen, Jeb P; Mullens, Bradley A

    2016-11-01

    The northern fowl mite, Ornithonyssus sylviarum, is the most damaging ectoparasite on egg-laying hens in the United States. One potential strategy for management is breeding for mite resistance. Genes of white leghorn chickens linked to the major histocompatibility complex (MHC) were previously identified as conferring more (B21 haplotype) or less (B15 haplotype) mite resistance. However, immune responses can be energetically costly to the host and affect the economic damage incurred from mite infestations. We tested energy costs (resting metabolic rate) of mite infestations on egg-laying birds of both MHC B-haplotypes. Resting metabolic rates were documented before (pre-) mite infestation, during (mid-) infestation, and after peak (late) mite infestation. Mite scores, economic parameters (egg production, feed consumption), and physiological aspects such as skin inflammation and skin temperature were recorded weekly. Across experiments and different infestation time points, resting metabolic rates generally were not affected by mite infestation or haplotype, although there were instances of lower metabolic rates in infested versus control hens. Skin temperatures were recorded both at the site of mite feeding damage (vent) and under the wing (no mites), which possibly would reflect a systemic fever response. Ambient temperatures modified skin surface temperature, which generally was not affected by mites or haplotype. Feed conversion efficiency was significantly worse (4.9 to 17.0% depending on trial) in birds infested with mites. Overall egg production and average egg weight were not affected significantly, although there was a trend toward reduced egg production (2 to 8%) by infested hens. The MHC haplotype significantly affected vent skin inflammation. Birds with the mite-resistant B21 haplotype showed earlier onset of inflammation, but a reduced overall area of inflammation compared to mite-susceptible B15 birds. No significant differences in resting energy

  17. Metabolism at Evolutionary Optimal States

    Directory of Open Access Journals (Sweden)

    Iraes Rabbers

    2015-06-01

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

  18. Comparative genomics reveals adaptation by Alteromonas sp. SN2 to marine tidal-flat conditions: cold tolerance and aromatic hydrocarbon metabolism.

    Directory of Open Access Journals (Sweden)

    Renukaradhya K Math

    Full Text Available Alteromonas species are globally distributed copiotrophic bacteria in marine habitats. Among these, sea-tidal flats are distinctive: undergoing seasonal temperature and oxygen-tension changes, plus periodic exposure to petroleum hydrocarbons. Strain SN2 of the genus Alteromonas was isolated from hydrocarbon-contaminated sea-tidal flat sediment and has been shown to metabolize aromatic hydrocarbons there. Strain SN2's genomic features were analyzed bioinformatically and compared to those of Alteromonas macleodii ecotypes: AltDE and ATCC 27126. Strain SN2's genome differs from that of the other two strains in: size, average nucleotide identity value, tRNA genes, noncoding RNAs, dioxygenase gene content, signal transduction genes, and the degree to which genes collected during the Global Ocean Sampling project are represented. Patterns in genetic characteristics (e.g., GC content, GC skew, Karlin signature, CRISPR gene homology indicate that strain SN2's genome architecture has been altered via horizontal gene transfer (HGT. Experiments proved that strain SN2 was far more cold tolerant, especially at 5°C, than the other two strains. Consistent with the HGT hypothesis, a total of 15 genomic islands in strain SN2 likely confer ecological fitness traits (especially membrane transport, aromatic hydrocarbon metabolism, and fatty acid biosynthesis specific to the adaptation of strain SN2 to its seasonally cold sea-tidal flat habitat.

  19. Metabolic regulation of inflammation.

    Science.gov (United States)

    Gaber, Timo; Strehl, Cindy; Buttgereit, Frank

    2017-05-01

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

  20. High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling.

    Science.gov (United States)

    Gómez-Ruiz, Ana; Milagro, Fermín I; Campión, Javier; Martínez, J Alfredo; de Miguel, Carlos

    2011-04-13

    The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP) and subcutaneous (SC) adipose tissue, comparing fasted (F) to not fasted (NF) rats that had been fed a control or high-fat (HF) diet for 72 days. Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4) were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test. High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF) induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF) also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF) in animals fed either diet. In RP adipocytes of control animals, food intake (NF) decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF) did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF) decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet. Animals fed a control-diet show a normal response to food intake (NF), with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet

  1. Metabolic Disorders

    Science.gov (United States)

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

  2. Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: Functional imaging in freely behaving rodent pups

    Directory of Open Access Journals (Sweden)

    Joerg eBock

    2012-05-01

    Full Text Available The trumpet-tailed rat or degu (Octodon degus is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behaviour. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method in 8 day old male degu pups the following stress conditions were compared: (A pups together with parents and siblings (control, (B separation of the litter from the parents, (C individual separation from parents and siblings, (D individual separation and presentation of maternal calls. Condition (B significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C, where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D maternal vocalizations reactivated brain activity in the cingulate and precentral medial cortex, nucleus accumbens and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other

  3. Colour and in vitro quality attributes of walnuts from different growing conditions correlate with key precursors of primary and secondary metabolism.

    Science.gov (United States)

    Fuentealba, Claudia; Hernández, Ignacia; Saa, Sebastian; Toledo, Lea; Burdiles, Pamela; Chirinos, Rosana; Campos, David; Brown, Patrick; Pedreschi, Romina

    2017-10-01

    Walnuts (Juglans regia L.) are well known for their flavour, nutritional and health properties. The light colour of walnuts is a quality attribute that leads to consumer preference. The aim of this study was to correlate attributes such as colour and antioxidant capacity with the precursors of primary and secondary metabolism. Two growing areas and four different colours of walnuts cv. Chandler from the central region of Chile were evaluated. Walnuts grown in the zone with Andes Mountains influence showed higher (p<0.05) sugar and unsaturated fatty acid contents, which could be attributed to lower minimum temperatures during seed filling. Extra light walnuts had higher (p<0.05) total phenolic compounds, antioxidant capacity and arbutin levels than amber walnuts. To the best of our knowledge, this is the first time that arbutin has been reported in walnuts and could provide the first insight into how enzymatic browning is prevented in the Chandler cultivar. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Characterization of fat metabolism in the fatty liver caused by a high-fat, low-carbohydrate diet: A study under equal energy conditions.

    Science.gov (United States)

    Kurosaka, Yuka; Shiroya, Yoko; Yamauchi, Hideki; Kitamura, Hiromi; Minato, Kumiko

    2017-05-20

    The pathology of fatty liver due to increased percentage of calories derived from fat without increased overall caloric intake is largely unclear. In this study, we aimed to characterize fat metabolism in rats with fatty liver resulting from consumption of a high-fat, low-carbohydrate (HFLC) diet without increased caloric intake. Four-week-old male Sprague-Dawley rats were randomly assigned to the control (Con) and HFLC groups, and rats were fed the corresponding diets ad libitum. Significant decreases in food intake per gram body weight were observed in the HFLC group compared with that in the Con group. Thus, there were no significant differences in body weights or caloric intake per gram body weight between the two groups. Marked progressive fat accumulation was observed in the livers of rats in the HFLC group, accompanied by suppression of de novo lipogenesis (DNL)-related proteins in the liver and increased leptin concentrations in the blood. In addition, electron microscopic observations revealed that many lipid droplets had accumulated within the hepatocytes, and mitochondrial numbers were reduced in the hepatocytes of rats in the HFLC group. Our findings confirmed that consumption of the HFLC diet induced fatty liver, even without increased caloric intake. Furthermore, DNL was not likely to be a crucial factor inducing fatty liver with standard energy intake. Instead, ultrastructural abnormalities found in mitochondria, which may cause a decline in β-oxidation, could contribute to the development of fatty liver. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Tobacco and metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Yatan Pal Singh Balhara

    2012-01-01

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

  6. The Mice Drawer System (MDS) Tissue Sharing Programme: effect of space conditions on skin metabolic activity and vascularization and potential impact of radiations in mice.

    Science.gov (United States)

    Nusgens, Betty; Lambert, Charles; Liu, Yi; Cancedda, Ranieri; Tavella, Sara; Ruggiu, Alessandra; Colige, Alain

    Our aim was to investigate the effect of prolonged microgravity on skin physiology in mice and to identify potentially altered metabolic and vascular parameters. Osteoporosis-induced microgravity is a well documented space flight problem in Man and animals.We have previously demonstrated that fibroblasts from the dermis also sense and react to mechanical forces issued from the surrounding extracellular matrix. Conversely, fibroblasts are able to remodel their environment by a dynamic process of synthesis and degradation. Fibroblasts and cells of the vascular network also react to soluble mediators secreted by the keratinocytes such as IL-1, IL-6, VEGF, .... Skin fibroblasts upon relaxation of mechanical tension adopt a catabolic phenotype and produce significant amount of IL-1 and IL-6, of various matrix metalloproteinases (MMP) while the collagen synthesis is reduced. In microgravity, we have shown that the expression of MMP-1 and IL-6 by dermal fibroblasts is increased indicating that cell might interpret micro-gravity as a mechanical relaxation. This concept is supported by a reduction of the actin stress fibers and focal adhesions in fibroblasts in microgravity. Altogether, microgravity might alter metabolic equilibrium of the skin and perhaps of other soft connective tissues such as tendons or interstitial matrix of internal organs. The Mice Drawer System (MDS) is an Italian Space Agency facility which is able to support mice onboard the International Space Station during long-duration exploration missions by providing living space, food, water, ventilation and light-ing. Details on the mission that took place from August 28, 2009 to November 27, 2009, can be found at the URL indicated below. A similar ground control mission has been performed using the same wild type and transgenic mice overexpressing OSF-1. Upon receiving mice at KSC, the team has collected pieces of skin that were handled for histological, transcriptomic and biochemical analyses. The

  7. Effects of low pH and raised temperature on egg production, hatching and metabolic rates of a Mediterranean copepod species (Acartia clausi under oligotrophic conditions

    Directory of Open Access Journals (Sweden)

    S. ZERVOUDAKI

    2013-09-01

    Full Text Available This study includes the first information on the combined effect of low pH and raised temperature on egg production rate (EP, hatching success (HS, excretion and respiration of the Mediterranean copepod Acartia clausi. Adult individuals of A. clausi and fresh surface seawater were collected at a coastal station in Saronikos Gulf during April 2012. Four different conditions were applied: two different pH levels (present: 8.09 and future: 7.83 at two temperature values (present: 16°C and present+4 °C= 20°C. EP and HS success decreased significantly over the duration of exposure at future pH at both temperature conditions. However, the analysis of the combined effect of pH, T, chlorophyll α and the duration of the experiments on EP and HS revealed that ocean acidification had no discernible effect, whereas warming; food and the duration of exposure were more significant for the reproductive output of A. clausi. Temperature appeared to have a positive effect on respiration and excretion. Acidification had no clear effect on respiration, but a negative effect on the A. clausi excretion was observed. Acidification and warming resulted in the increase of the excretion rate and the increase was higher than that observed by warming only. Our findings showed that a direct effect of ocean acidification on copepod’s vital rates was not obvious, except maybe in the case of excretion. Therefore, the combination of acidification with the ambient oligotrophic conditions and the warming could result in species being less able to allocate resources for coping with multiple stressors.

  8. Novel insights into E. coli's hexuronate metabolism: KduI facilitates the conversion of galacturonate and glucuronate under osmotic stress conditions.

    Directory of Open Access Journals (Sweden)

    Monique Rothe

    Full Text Available Using a gnotobiotic mouse model, we previously observed the upregulation of 2-deoxy-D-gluconate 3-dehydrogenase (KduD in intestinal E. coli of mice fed a lactose-rich diet and the downregulation of this enzyme and of 5-keto 4-deoxyuronate isomerase (KduI on a casein-rich diet. The present study aimed to define the role of the so far poorly characterized E. coli proteins KduD and KduI in vitro. Galacturonate and glucuronate induced kduD and kduI gene expression 3-fold and 7 to 11-fold, respectively, under aerobic conditions as well as 9 to 20-fold and 19 to 54-fold, respectively, under anaerobic conditions. KduI facilitated the breakdown of these hexuronates. In E. coli, galacturonate and glucuronate are normally degraded by UxaABC and UxuAB. However, osmotic stress represses the expression of the corresponding genes in an OxyR-dependent manner. When grown in the presence of galacturonate or glucuronate, kduID-deficient E. coli had a 30% to 80% lower maximal cell density and 1.5 to 2-fold longer doubling times under osmotic stress conditions than wild type E. coli. Growth on lactose promoted the intracellular formation of hexuronates, which possibly explain the induction of KduD on a lactose-rich diet. These results indicate a novel function of KduI and KduD in E. coli and demonstrate the crucial influence of osmotic stress on the gene expression of hexuronate degrading enzymes.

  9. Genomic and Evolutionary Perspectives on Sulfur Metabolism in Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) are anaerobic photoautotrophs that oxidize sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for growth. We present here an analysis of the distribution and evolution of enzymes involved in oxidation of sulfur compounds in GSB based on genome sequence......, in combination with phylogenetic analyses, suggests that the Dsr system in GSB could be a recent acquisition, which was obtained by lateral gene transfer in part from sulfideoxidizing bacteria and in part from sulfate-reducing bacteria. All thiosulfate-utilizing GSB strains have an identical sox gene cluster...... in some, but not all sulfide-utilizing strains. Even though different GSB strains superficially exhibit a similar sulfur oxidation phenotype, this may be caused by different combinations of enzymes. Thus, genome analyses have revealed that GSB have greater diversity in sulfur metabolism than previously...

  10. The condition of the metabolism of the brain and liver during the experimental application of a microwave field of nonthermal intensities

    Energy Technology Data Exchange (ETDEWEB)

    Belokrinitskii, V.S.; Tomashevskaia, L.A.

    1982-10-01

    The effects of small doses of a nonthermal microwave field (50 microwatts/sq cm for 6 hr), repeated 10 times, on histochemical and biochemical parameters of the brain and liver of white rats are investigated. Also studied are the resistance of the animals following irradiation to hypoxia and to a single larger dose of radiation. Results show that the radiation exposures change the structural-functional basis of the mechanisms of the regulation of oxidative processes, disconnects oxidative phosphorylation, and causes compensatory increases in glycolysis and in the synthesis of enzymes. In addition, it is found that exposures to small doses of radiation increase the resistance of the animals to conditions of hypoxia.

  11. Metabolically active microbial communities in marine sediment under high-CO(2) and low-pH extremes.

    Science.gov (United States)

    Yanagawa, Katsunori; Morono, Yuki; de Beer, Dirk; Haeckel, Matthias; Sunamura, Michinari; Futagami, Taiki; Hoshino, Tatsuhiko; Terada, Takeshi; Nakamura, Ko-Ichi; Urabe, Tetsuro; Rehder, Gregor; Boetius, Antje; Inagaki, Fumio

    2013-03-01

    Sediment-hosting hydrothermal systems in the Okinawa Trough maintain a large amount of liquid, supercritical and hydrate phases of CO(2) in the seabed. The emission of CO(2) may critically impact the geochemical, geophysical and ecological characteristics of the deep-sea sedimentary environment. So far it remains unclear whether microbial communities that have been detected in such high-CO(2) and low-pH habitats are metabolically active, and if so, what the biogeochemical and ecological consequences for the environment are. In this study, RNA-based molecular approaches and radioactive tracer-based respiration rate assays were combined to study the density, diversity and metabolic activity of microbial communities in CO(2)-seep sediment at the Yonaguni Knoll IV hydrothermal field of the southern Okinawa Trough. In general, the number of microbes decreased sharply with increasing sediment depth and CO(2) concentration. Phylogenetic analyses of community structure using reverse-transcribed 16S ribosomal RNA showed that the active microbial community became less diverse with increasing sediment depth and CO(2) concentration, indicating that microbial activity and community structure are sensitive to CO(2) venting. Analyses of RNA-based pyrosequences and catalyzed reporter deposition-fluorescence in situ hybridization data revealed that members of the SEEP-SRB2 group within the Deltaproteobacteria and anaerobic methanotrophic archaea (ANME-2a and -2c) were confined to the top seafloor, and active archaea were not detected in deeper sediments (13-30 cm in depth) characterized by high CO(2). Measurement of the potential sulfate reduction rate at pH conditions of 3-9 with and without methane in the headspace indicated that acidophilic sulfate reduction possibly occurs in the presence of methane, even at very low pH of 3. These results suggest that some members of the anaerobic methanotrophs and sulfate reducers can adapt to the CO(2)-seep sedimentary environment; however

  12. Metabolically active microbial communities in marine sediment under high-CO2 and low-pH extremes

    Science.gov (United States)

    Yanagawa, Katsunori; Morono, Yuki; de Beer, Dirk; Haeckel, Matthias; Sunamura, Michinari; Futagami, Taiki; Hoshino, Tatsuhiko; Terada, Takeshi; Nakamura, Ko-ichi; Urabe, Tetsuro; Rehder, Gregor; Boetius, Antje; Inagaki, Fumio

    2013-01-01

    Sediment-hosting hydrothermal systems in the Okinawa Trough maintain a large amount of liquid, supercritical and hydrate phases of CO2 in the seabed. The emission of CO2 may critically impact the geochemical, geophysical and ecological characteristics of the deep-sea sedimentary environment. So far it remains unclear whether microbial communities that have been detected in such high-CO2 and low-pH habitats are metabolically active, and if so, what the biogeochemical and ecological consequences for the environment are. In this study, RNA-based molecular approaches and radioactive tracer-based respiration rate assays were combined to study the density, diversity and metabolic activity of microbial communities in CO2-seep sediment at the Yonaguni Knoll IV hydrothermal field of the southern Okinawa Trough. In general, the number of microbes decreased sharply with increasing sediment depth and CO2 concentration. Phylogenetic analyses of community structure using reverse-transcribed 16S ribosomal RNA showed that the active microbial community became less diverse with increasing sediment depth and CO2 concentration, indicating that microbial activity and community structure are sensitive to CO2 venting. Analyses of RNA-based pyrosequences and catalyzed reporter deposition-fluorescence in situ hybridization data revealed that members of the SEEP-SRB2 group within the Deltaproteobacteria and anaerobic methanotrophic archaea (ANME-2a and -2c) were confined to the top seafloor, and active archaea were not detected in deeper sediments (13–30 cm in depth) characterized by high CO2. Measurement of the potential sulfate reduction rate at pH conditions of 3–9 with and without methane in the headspace indicated that acidophilic sulfate reduction possibly occurs in the presence of methane, even at very low pH of 3. These results suggest that some members of the anaerobic methanotrophs and sulfate reducers can adapt to the CO2-seep sedimentary environment; however, CO2 and p

  13. Nucleotide Metabolism

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  14. Metabolic myopathies

    Science.gov (United States)

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

    1994-01-01

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

  15. Distribution and metabolism of quaternary amines in salt marshes

    Science.gov (United States)

    King, Gary M.

    1985-01-01

    Quaternary amines such as glycine betaine (GBT) are common osmotically active solutes in much of the marine biota. GBT is accumulated by various bacteria, algae, higher plants, invertebrates, and vertebrates in response to salinity or water stresses; in some species, GBT occurs at tens to hundreds of millimolar concentrations and can account for a significant fraction of total nitrogen. Initial studies suggest that GBT is readily converted to two potential methane precursors, trimethylamine (TMA) and acetate, in anoxic sediments. TMA is apparently the most important methane precursor in surface sediments containing sulfate reducing bacteria. In salt marshes, the bulk of the methane formed may be due to the metabolism of TMA rather than other substrates. Current research is focussed on testing this hypothesis and on determining the role of quaternary amino osmoregulatory solutes in methane fluxes from marine environments. Preliminary studies have dealt with several problems: (1) determination of GBT concentrations in the dominant flora and fauna of salt marshes; (2) synthesis of radiolabelled GBT for metabolic studies; and (3) determination of fates of BGT in marine sediments using radiotracers. Both GC and HPLC techniques have been used to assay GBT concentrations in plant and animal tissues. S. alterniflora is probably the only significant source of GBT (and indirectly of methane) since the biomass and distribution of most other species is limited. Current estimates suggest that S. alterniflora GBT could account for most of the methane efflux from salt marshes.

  16. Metabolic Syndrome after Kidney Transplantation - Are You at Risk?

    Science.gov (United States)

    ... Events Advocacy Donate A to Z Health Guide Metabolic Syndrome after Kidney Transplantation: —Are You at Risk? Print ... be talking with your physician about something called metabolic syndrome. Metabolic syndrome is a condition where you have ...

  17. Metabolic Syndrome

    Science.gov (United States)

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

  18. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

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

  19. Metabolism of

    African Journals Online (AJOL)

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

  20. [Metabolic acidosis].

    Science.gov (United States)

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

    2016-01-01

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

  1. Metabolic depression in fish measured by direct calorimetry: A review

    NARCIS (Netherlands)

    Ginneken, van V.J.T.; Thillart, van den G.

    2009-01-01

    In nature under adverse conditions like low oxygen conditions or starvation fish often lower their metabolism: `metabolic depression¿. This strategy of lowering the metabolic rate is a survival strategy and is used to save energy stores and diminish end-product accumulation. The overall metabolic

  2. Drug-Induced Metabolic Acidosis

    Science.gov (United States)

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

    2015-01-01

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

  3. Identification of Metabolic Pathway Systems

    National Research Council Canada - National Science Library

    Dolatshahi, Sepideh; Voit, Eberhard O

    2016-01-01

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

  4. 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 ...

  5. METABOLIC SYNDROME

    OpenAIRE

    Dikanović, Marinko

    2015-01-01

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

  6. Extranuclear Sirtuins and Metabolic Stress.

    Science.gov (United States)

    Elkhwanky, Mahmoud-Sobhy; Hakkola, Jukka

    2018-03-10

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

  7. Structural Control of Metabolic Flux

    Science.gov (United States)

    Sajitz-Hermstein, Max; Nikoloski, Zoran

    2013-01-01

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

  8. Abatement of acid mine drainage : sulfate reduction and iron sulfide formation at low pH conditions

    Energy Technology Data Exchange (ETDEWEB)

    Meier, J.; Piva, A.; Lutzu, G.; Fortin, D. [Ottawa Univ., ON (Canada). Dept. of Earth Sciences

    2007-07-01

    The oxidation of metal sulfides that accumulate during ore and coal mining from overburden and tailings material cause the formation of acidic and metal rich waters which are generally referred to as acid mine drainage (AMD). Environments impacted by AMD are generally rich in ferric iron and sulfate, providing possible habitats for iron and sulfate reducing microorganisms. Microbial iron and sulfate reduction have been reported for mine tailings and sediments of acidic pit lakes. Bioremediation strategies for the treatment of AMD can implement dissimilatory sulfate reduction to generate alkalinity and to precipitate metal cations. The success of on-site treatments depends on the performance of the microorganisms and on the achievement of metal sulfide formation under the prevailing conditions. This paper presented the results of an investigation on sulfate reduction and iron sulfide formation under low pH conditions and characterized bacterial communities and mineral precipitates emerging under different pH values. The paper discussed the materials and methods used in the study, including source of enrichment culture; medium and experimental set up; and analysis. The results of this study demonstrated that sulfate reducing bacteria could be enriched under low pH conditions in the presence of elevated aluminum and ferrous iron concentrations and with hydrogen/carbon dioxide as the electron donor/carbon source. 17 refs., 2 tabs., 4 figs.

  9. 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 ...

  10. Role of genetic factors in the development of metabolic and immune response in the cases of acute respiratory infections complicated by pneumonia in the conditions of the far north in various ethnic groups

    Directory of Open Access Journals (Sweden)

    V. V. Ivanova

    2012-01-01

     intensity, regulating cell activation, synthesis of protection mediators and the level of hormones in blood, as well as cytotoxic properties of lymphocytes interact with each other, influencing the regulation of metabolism and separate mechanisms of immune response. This type of influence is to a greater degree expressed in children of Yakuts to compare with Russians. Depending on the combination of acetylation type and free-radical oxidation level during an acute phase of acute respiratory infection there is a change of a profile of immune protection due to the activation of cellular Th1-response or IgA production in mucous membranes. It is demonstrated that the stimulation of cellular response is more characteristic for Yakut-children, and humoral one for Russian-children. There have been revealed the features of pneumonia course, the metabolic laws of the development of adaptation response to infectious stress and the maintenance of immune homeostasis with taking into account a genophenotype of acute respiratory infection complicated by pneumonia in children of the Far North. The value of the research of N-АТ activity level in cases of acute respiratory infection complicated by pneumonia in ill children (Yakuts and Russians in the conditions of the Far North is underlined as the reason for its further use as a marker of the predisposing factor for complicated acute respiratory infection and other infections.

  11. Metabolic Engineering

    Indian Academy of Sciences (India)

    IAS Admin

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

  12. Metabolic Analysis

    Science.gov (United States)

    Tolstikov, Vladimir V.

    Analysis of the metabolome with coverage of all of the possibly detectable components in the sample, rather than analysis of each individual metabolite at a given time, can be accomplished by metabolic