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Sample records for biogenic uraninite produced

  1. Comparative dissolution kinetics of biogenic and chemogenic uraninite under oxidizing conditions in the presence of carbonate

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    Ulrich, Kai-Uwe; Ilton, Eugene S.; Veeramani, Harish; Sharp, Jonathan O.; Bernier-Latmani, Rizlan; Schofield, Eleanor J.; Bargar, John R.; Giammar, Daniel E.

    2009-10-01

    The long-term stability of biogenic uraninite with respect to oxidative dissolution is pivotal to the success of in situ bioreduction strategies for the subsurface remediation of uranium legacies. Batch and flow-through dissolution experiments were conducted along with spectroscopic analyses to compare biogenic uraninite nanoparticles obtained from Shewanella oneidensis MR-1 and chemogenic UO 2.00 with respect to their equilibrium solubility, dissolution mechanisms, and dissolution kinetics in water of varied oxygen and carbonate concentrations. Both materials exhibited a similar intrinsic solubility of ˜10 -8 M under reducing conditions. The two materials had comparable dissolution rates under anoxic as well as oxidizing conditions, consistent with structural bulk homology of biogenic and stoichiometric uraninite. Carbonate reversibly promoted uraninite dissolution under both moderately oxidizing and reducing conditions, and the biogenic material yielded higher surface area-normalized dissolution rates than the chemogenic. This difference is in accordance with the higher proportion of U(V) detected on the biogenic uraninite surface by means of X-ray photoelectron spectroscopy. Reasonable sources of a stable U(V)-bearing intermediate phase are discussed. The observed increase of the dissolution rates can be explained by carbonate complexation of U(V) facilitating the detachment of U(V) from the uraninite surface. The fraction of surface-associated U(VI) increased with dissolved oxygen concentration. Simultaneously, X-ray absorption spectra showed conversion of the bulk from UO 2.0 to UO 2+x. In equilibrium with air, combined spectroscopic results support the formation of a near-surface layer of approximate composition UO 2.25 (U 4O 9) coated by an outer layer of U(VI). This result is in accordance with flow-through dissolution experiments that indicate control of the dissolution rate of surface-oxidized uraninite by the solubility of metaschoepite under the tested

  2. Oxidative dissolution of biogenic uraninite in groundwater at Old Rifle, CO

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    Campbell, Kate M.; Veeramani, Harish; Ulrich, Kai-Uwe; Blue, Lisa Y.; Giammar, Dianiel E.; Bernier-Latmani, Rizlan; Stubbs, Joanne E.; Suvorova, Elena; Yabusaki, Steve; Lezama-Pacheco, Juan S.; Mehta, Apurva; Long, Philip E.; Bargar, John R.

    2011-01-01

    Reductive bioremediation is currently being explored as a possible strategy for uranium-contaminated aquifers such as the Old Rifle site (Colorado). The stability of U(IV) phases under oxidizing conditions is key to the performance of this procedure. An in situ method was developed to study oxidative dissolution of biogenic uraninite (UO2), a desirable U(VI) bioreduction product, in the Old Rifle, CO, aquifer under different variable oxygen conditions. Overall uranium loss rates were 50–100 times slower than laboratory rates. After accounting for molecular diffusion through the sample holders, a reactive transport model using laboratory dissolution rates was able to predict overall uranium loss. The presence of biomass further retarded diffusion and oxidation rates. These results confirm the importance of diffusion in controlling in-aquifer U(IV) oxidation rates. Upon retrieval, uraninite was found to be free of U(VI), indicating dissolution occurred via oxidation and removal of surface atoms. Interaction of groundwater solutes such as Ca2+ or silicate with uraninite surfaces also may retard in-aquifer U loss rates. These results indicate that the prolonged stability of U(IV) species in aquifers is strongly influenced by permeability, the presence of bacterial cells and cell exudates, and groundwater geochemistry.

  3. Biogenic uraninite precipitation and its reoxidation by iron(III) (hydr)oxides: A reaction modeling approach

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    Spycher, Nicolas F.; Issarangkun, Montarat; Stewart, Brandy D.; Sevinç Şengör, S.; Belding, Eileen; Ginn, Tim R.; Peyton, Brent M.; Sani, Rajesh K.

    2011-08-01

    One option for immobilizing uranium present in subsurface contaminated groundwater is in situ bioremediation, whereby dissimilatory metal-reducing bacteria and/or sulfate-reducing bacteria are stimulated to catalyze the reduction of soluble U(VI) and precipitate it as uraninite (UO 2). This is typically accomplished by amending groundwater with an organic electron donor. It has been shown, however, that once the electron donor is entirely consumed, Fe(III) (hydr)oxides can reoxidize biogenically produced UO 2, thus potentially impeding cleanup efforts. On the basis of published experiments showing that such reoxidation takes place even under highly reducing conditions (e.g., sulfate-reducing conditions), thermodynamic and kinetic constraints affecting this reoxidation are examined using multicomponent biogeochemical simulations, with particular focus on the role of sulfide and Fe(II) in solution. The solubility of UO 2 and Fe(III) (hydr)oxides are presented, and the effect of nanoscale particle size on stability is discussed. Thermodynamically, sulfide is preferentially oxidized by Fe(III) (hydr)oxides, compared to biogenic UO 2, and for this reason the relative rates of sulfide and UO 2 oxidation play a key role on whether or not UO 2 reoxidizes. The amount of Fe(II) in solution is another important factor, with the precipitation of Fe(II) minerals lowering the Fe +2 activity in solution and increasing the potential for both sulfide and UO 2 reoxidation. The greater (and unintuitive) UO 2 reoxidation by hematite compared to ferrihydrite previously reported in some experiments can be explained by the exhaustion of this mineral from reaction with sulfide. Simulations also confirm previous studies suggesting that carbonate produced by the degradation of organic electron donors used for bioreduction may significantly increase the potential for UO 2 reoxidation through formation of uranyl carbonate aqueous complexes.

  4. Structural Characterization of Biogenic Manganese Oxides Produced in Sea Water

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    Webb, S. M.; Bargar, J. R.; Tebo, B. M.

    2003-12-01

    Manganese oxides have been coined as the "scavengers of the sea" and play important roles in both marine and freshwater systems. Natural manganese oxide nanoparticles and grain coatings are ubiquitous in the environment and profoundly impact the quality of sediments via their ability to degrade and sequester contaminants. These oxides are believed to form dominantly via oxidation of Mn(II) by marine and freshwater bacteria and have extremely high sorptive capacities for heavy metals. We have used XANES, EXAFS, and synchrotron (SR)-XRD techniques to study biogenic manganese oxides produced by spores of the marine Bacillus sp., strain SG-1 in seawater as a function of reaction time under fully in-situ conditions. The primary biogenic solid-phase Mn oxide product is a hexagonal layered phyollomanganate with an oxidation state similar to that in delta-MnO2. XRD data show the biooxides to have a phyllomanganate 10 basal plane spacing, suggesting the interlayer is hydrated and contains calcium. As the experiment continues, the initial biooxide changes to show triclinic symmetry. Fits to these EXAFS spectra suggest the octahedral layers have low Mn octahedral site vacancies in the lattice and the latyers bend to accommodate Jahn-Teller distortions creating the change in symmetry. The oxides observed in this study as models of Mn(II) bio-oxidation may be representative of the most abundant manganese oxide phase suspended in the oxic and sub-oxic zones of the oceanic water column.

  5. Concentration of Biogenic Amines in ‘Pinot Noir’ Wines Produced in Croatia

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    Ana Jeromel

    2012-03-01

    Full Text Available The origins of biogenic amines are sound grapes, alcoholic fermentations, malolactic fermentation and microbial activities during wine storage. These biologically produced amines are essential at low concentrations for optimal metabolic and physiological functions in animals, plants and micro-organisms. During alcoholic fermentation the degree of maceration is the first factor that affects the extraction of compounds present in the grape skin, among them aminoacids, precursors of biogenic amines. The aim of the present work was to study the changes of the concentration of biogenic amines in wines made from Vitis vinifera ‘Pinot noir’ from Plešivica (vintage 2009 produced with classical maceration, cold maceration and use of sur lie method. Biogenic amines were quantified using a reversed-phase high performance liquid chromatography (HPLC with fluorescence detection after pre-column derivatization with o-phthalaldehyde (OPA. In ‘Pinot noir’ wines tested, histamine was the most abundant biogenic amine followed by tryptamine and 2-Phenylethylamine. Total amount of biogenic amines ranged from 8.72 mg/L in wines made with classical maceration up to 9.34 mg/L in sur lie wines. In summary, from the results obtained in this study, it can be concluded that sur lie technology can influence the formation of biogenic acids since the release of amino acids is probably more pronounced in wines aged with lees and stirred weekly. No significant differences were found in the concentration of biogenic amines in relation to the used maceration process.

  6. Enhancement of Biogenic Coalbed Methane Production and Back Injection of Coalbed Methane Co-Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Song Jin

    2007-05-31

    Biogenic methane is a common constituent in deep subsurface environments such as coalbeds and oil shale beds. Coalbed methane (CBM) makes significant contributions to world natural gas industry and CBM production continues to increase. With increasing CBM production, the production of CBM co-produced water increases, which is an environmental concern. This study investigated the feasibility in re-using CBM co-produced water and other high sodic/saline water to enhance biogenic methane production from coal and other unconventional sources, such as oil shale. Microcosms were established with the selected carbon sources which included coal, oil shale, lignite, peat, and diesel-contaminated soil. Each microcosm contained either CBM coproduced water or groundwater with various enhancement and inhibitor combinations. Results indicated that the addition of nutrients and nutrients with additional carbon can enhance biogenic methane production from coal and oil shale. Methane production from oil shale was much greater than that from coal, which is possibly due to the greater amount of available Dissolved Organic Carbon (DOC) from oil shale. Inconclusive results were observed from the other sources since the incubation period was too low. WRI is continuing studies with biogenic methane production from oil shale.

  7. PCR detection of foodborne bacteria producing the biogenic amines histamine, tyramine, putrescine, and cadaverine.

    Science.gov (United States)

    de las Rivas, Blanca; Marcobal, Angela; Carrascosa, Alfonso V; Muñoz, Rosario

    2006-10-01

    This study describes an easy PCR method for the detection of foodborne bacteria that potentially produce histamine, tyramine, putrescine, and cadaverine. Synthetic oligonucleotide pairs for the specific detection of the gene coding for each group of bacterial histidine, tyrosine, ornithine, or lysine decarboxylases were designed. Under the conditions used in this study, the assay yielded fragments of 372 and 531 bp from histidine decarboxylase-encoding genes, a 825-bp fragment from tyrosine decarboxylases, fragments of 624 and 1,440 bp from ornithine decarboxylases, and 1,098- and 1,185-bp fragments from lysine decarboxylases. This is the first PCR method for detection of cadaverine-producing bacteria. The method was successfully applied to several biogenic amine-producing bacterial strains.

  8. Biogenic amine producing capability of bacterial populations isolated during processing of different types of dry fermented sausages

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    M. Vincenzini

    2010-04-01

    Full Text Available In order to assess the distribution of the biogenic amine (BA producing capability within the bacterial populations occurring during production of dry fermented sausages, four different types of sausage processing, three with the use of starter cultures and one without, were investigated. All the main bacterial populations involved in the sausage processing showed a diffuse and strain dependent capability to produce BAs. However, quantitative determination of individual BAs produced by the bacterial isolates suggests an important role of enterococci in the accumulation of tyramine, the most abundant biogenic amine found in all investigated sausages.

  9. Biofilm-forming capacity in biogenic amine-producing bacteria isolated from dairy products.

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    Maria eDiaz

    2016-05-01

    Full Text Available Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria - both spoilage and pathogenic. However, the capacity of biogenic amine (BA-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri and 7 Lactobacillus parabuchneri, all isolated from dairy products. Strains of all the tested species - except for L. vaginalis - were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms.

  10. Occurrence of biogenic amines in beers produced with malted organic Emmer wheat (Triticum dicoccum).

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    Mozzon, Massimo; Boselli, Emanuele; Obiedziński, Mieczysław W; Frega, Natale G

    2015-01-01

    Because several groups of microorganisms are able to decarboxylate amino acids, the presence of biogenic amines (BA) can be seen as an index of the microbiological quality of the brewing process. BAs were quantified for the first time in the intermediate products and craft beers produced with malted organic Emmer wheat (Triticum dicoccum) in a small size brewery in order to assess the possible presence of critical control points related to biological hazard in the brewing process. BA levels in beers produced exclusively from malted organic Emmer wheat were between 15.4 and 25.2 mg l(-1) in the samples of light beer (Lt) and between 8.9 and 15.3 mg l(-1) in double malt beers (DM) ready for consumption (the beers stored for 90 days at 1-2°C). Cadaverine and tyramine were the main BAs in the Lt and DM beers, respectively. Increased concentrations of BAs seemed to be more related to the heat treatment of the processing product during mashing and wort boiling, rather than to the fermentation process. Much lower concentrations were found in finished beers obtained from 50% malted organic Emmer wheat and 50% malted barley (up to 3.2 mg l(-1)) or from 30% malted Emmer wheat (up to 8.3 mg l(-1)). Thus, Emmer wheat malt can be a useful alternative to wheat and spelt for the production of beer with a limited content of BA, if the processing technology is kept under control.

  11. Sorption of arsenic to biogenic iron (oxyhydr)oxides produced in circumneutral environments

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    Sowers, Tyler D.; Harrington, James M.; Polizzotto, Matthew L.; Duckworth, Owen W.

    2017-02-01

    Arsenic (As) is a widespread and problematic pollutant that can be derived from natural or anthropogenic sources. Iron (oxyhydr)oxides readily sorb As and thus play critical roles in As cycling in terrestrial environments; however, little is known about the affinity and mechanism of As sorption by biogenic iron (oxyhydr)oxides formed in circumneutral environments. To investigate this, we conducted sorption isotherm and kinetics experiments to compare As(V) and As(III) sorption to synthetic 2-line ferrihydrite and iron biominerals harvested from the hyporheic zone of an uncontaminated creek. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify both As(V) and As(III), and X-ray absorption spectroscopy (XAS) was utilized to obtain As and Fe K-edge spectra for As(V) and As(III) sorbed to environmentally collected and laboratory produced Fe(III) minerals. All environmental Fe(III) biominerals were determined to be structurally similar to 2-line ferrihydrite. However, environmental Fe(III) biominerals have a surface area normalized affinity for As(V) and for As(III) that is greater than or equivalent to synthetic 2-line ferrihydrite. Whereas the extent of sorption was similar for As(III) on all minerals, As(V) sorption to environmental Fe(III) biominerals was approximately three times higher than what was observed for synthetic 2-line ferrihydrite. Structural modeling of EXAFS spectra revealed that the same surface complexation structure was formed by As(V) and by As(III) on environmental Fe(III) biominerals and ferrihydrite. These results suggest that, despite similarities in binding mechanisms, Fe(III) biominerals may be more reactive sorbents that synthetic surrogates often used to model environmental reactivity.

  12. Application of biogenic carbon dioxide produced by yeast with different carbon sources for attraction of mosquitoes towards adult mosquito traps.

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    Sukumaran, D; Ponmariappan, S; Sharma, Atul K; Jha, Hemendra K; Wasu, Yogesh H; Sharma, Ajay K

    2016-04-01

    Surveillance is a prime requisite for controlling arthropod vectors like mosquitoes that transmit diseases such as malaria, dengue and chikungunya. Carbon dioxide (CO2) is one of the main cues from vertebrate breath that attracts mosquitoes towards the host. Hence, CO2 is used as an attractant during surveillance of mosquitoes either from commercial cylinders or dry ice for mosquito traps. In the present study, the biogenic carbon dioxide production was optimized with different carbon sources such as glucose, simple sugar and jaggery with and without yeast peptone dextrose (YPD) media using commercial baker's yeast. The results showed that yeast produced more biogenic CO2 with simple sugar as compared to other carbon sources. Further substrate concentration was optimized for the continuous production of biogenic CO2 for a minimum of 12 h by using 10 g of baker's yeast with 50 g of simple sugar added to 1.5 l distilled water (without YPD media) in a 2-l plastic bottle. This setup was applied in field condition along with two different mosquito traps namely Mosquito Killing System (MKS) and Biogents Sentinel (BGS) trap. Biogenic CO2 from this setup has increased the trapping efficiency of MKS by 6.48-fold for Culex quinquefasciatus, 2.62-fold for Aedes albopictus and 1.5-fold for Anopheles stephensi. In the case of BGS, the efficiency was found to be increased by 3.54-fold for Ae. albopictus, 4.33-fold for An. stephensi and 1.3-fold for Armigeres subalbatus mosquitoes. On the whole, plastic bottle setup releasing biogenic CO2 from sugar and yeast has increased the efficiency of MKS traps by 6.38-fold and 2.74-fold for BGS traps as compared to traps without biogenic CO2. The present study reveals that, among different carbon sources used, simple sugar as a substance (which is economical and readily available across the world) yielded maximum biogenic CO2 with yeast. This setup can be used as an alternative to CO2 cylinder and dry ice in any adult mosquito traps to

  13. Sandbox experiments on Uraninite Ore: ERT and SP measurments.

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    Singh, R. K.

    2015-12-01

    Nuclear energy, considering its own intrinsic merits, would be a leading source for meeting the energy requirement in present and future scenario. Concealed Uranium deposits under sedimentary cover, with poor surface indications calls for reorientation of survey with large inputs involving integrated geophysical approach. Sand Box experiments have been carried out over Uraninite ore. The tank is a glass fish tank (height 39 cm, length 75 cm, width 30 cm). It was filled with sand up to 35 cm high. The sand was saturated from below to minimize the entrapment of the gas bubbles. The average size for sand grains is ~ 0.295mm. The formation factor of the sand is 3.5, with a negligible surface conductivity because of the coarse nature of the sand grains. The dimension of considered Uraninite ore sample is 4cm x 4cm x 4cm. The depth of top of the ore sample is kept at 3cm. In this paper both resistivity and self-potential measurements were carried out for possible detection of Uraninite. The resistivity measurements were made with 64 non-polarizable electrodes using Electrical Resistivity Tomography (ERT) equipment of FlashRes Universal developed by ZZ Resistivity Imaging Pty. Ltd. We have used screws of length 3cm as electrodes. The separation between these electrodes are ~ 1cm. The resistivity tomography results clearly outlines the target Uraninite body. The resistivity tomography results also detects small heterogeneities associated with air bubbles possibly due to unsaturated pore spaces. SP measurements were made using two non-polarizing Pb/PbCl2 electrodes and a Fluke 289 voltmeter (sensitivity 0.001 mV, internal impedance 100 MOhm). The reference electrode was located on the corner of the sandbox. The other electrode was used to scan the electrical potential at the surface of the sand. SP measurements were made with a spacing of 3 cm over the same ERT profile. The SP results also shows a dip (or a low SP anomaly) over the target ore body sample. Thus, both SP and

  14. Effect of the interaction between a low tyramine-producing Lactobacillus and proteolytic staphylococci on biogenic amine production during ripening and storage of dry sausages.

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    Bover-Cid, S; Izquierdo-Pulido, M; Vidal-Carou, M C

    2001-04-11

    The interaction between tyrosine-decarboxylase and proteolytic activities of a Lactobacillus curvatus and Staphylococcus xylosus, respectively, on biogenic amine production during the ripening and the storage of dry fermented sausages was investigated. Water content, pH, proteolysis parameters, microbial counts, and biogenic amine contents were monitored in spontaneously and starter fermented sausages. The use of proteolytic staphylococci as starter resulted in a higher content of non-protein nitrogen and total free amino acids. Tyramine was the main amine produced in all batches. However, tyrosine-decarboxylase activity of the L. curvatus starter strain was weak and yielded lower amounts of tyramine than those produced by the wild mioroflora in the control batch. Association between tyramine production and proteolysis could only be established in a defectively dried batch. Putrescine and cadaverine accumulation was efficiently reduced in the starter-mediated fermentation, in agreement with the lower development of enterobacteria. Phenylethylamine and tryptamine were only detected in the spontaneously fermented sausages, while histamine, spermine and spermidine did not vary during the ripening. Biogenic amine levels and related parameters showed significant changes during the storage of dry sausages depending on the temperature and the batch. As a general rule, changes in the pH, proteolysis, microbial counts, and biogenic amine contents were stronger at 19 degrees C than at 4 degrees C. The results suggest that refrigeration would be advisable for preventing further accumulation of biogenic amines during the storage of dry fermented sausages.

  15. Recent Advances in the Application of Metabolomics to Studies of Biogenic Volatile Organic Compounds (BVOC Produced by Plant

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    Yoko Iijima

    2014-08-01

    Full Text Available In many plants, biogenic volatile organic compounds (BVOCs are produced as specialized metabolites that contribute to the characteristics of each plant. The varieties and composition of BVOCs are chemically diverse by plant species and the circumstances in which the plants grow, and also influenced by herbivory damage and pathogen infection. Plant-produced BVOCs are receptive to many organisms, from microorganisms to human, as both airborne attractants and repellants. In addition, it is known that some BVOCs act as signals to prime a plant for the defense response in plant-to-plant communications. The compositional profiles of BVOCs can, thus, have profound influences in the physiological and ecological aspects of living organisms. Apart from that, some of them are commercially valuable as aroma/flavor compounds for human. Metabolomic technologies have recently revealed new insights in biological systems through metabolic dynamics. Here, the recent advances in metabolomics technologies focusing on plant-produced BVOC analyses are overviewed. Their application markedly improves our knowledge of the role of BVOCs in chemosystematics, ecological influences, and aroma research, as well as being useful to prove the biosynthetic mechanisms of BVOCs.

  16. On the oxidation of uraninite from natural reactor cores

    Energy Technology Data Exchange (ETDEWEB)

    Cui, D.; Eriksen, T.; Eklund, U.B.

    1999-07-01

    Natural nuclear reactors provide unique evidence in helping to understand the processes that might occur over long timescales in radioactive waste disposal sites. In the presented work, the extent and kinetics of oxidation of core material from the Oklo-Bangombe natural reactors are investigated. The X-ray powder diffraction analysis shows that the uraninites core samples from the Bangombe Reactor and Oklo Reactor 2, and Oklo Reactor 13 have the same unit-cell parameters as synthetic UO{sub 2.25}. A significant amount of fourmarierite, Pb(UO{sub 2}){sub 4}O{sub 3}(OH){sub 4}.4H{sub 2}O, was identified in the core samples from two shallow reactors Bangombe and Oklo 2, but not in the deeper reactor Oklo 13. The results of U(IV)/U(IV) measurements indicate that the extent of oxidative weathering of shallow reactors (Bangombe and Oklo 2) is greater than for the deeper reactor Oklo 13. Evaporable organic compounds found in the uraninite inclusion containing bitumen at the edge of Okelobondo Reactor (400 C) and in the black shale immediately above the Bangombe Reactor (260 C) may work as a reducing buffer or/and a hydrophobic water shield to depress the oxidative dissolution of the uraninite cores.

  17. Genome Sequence of Lactobacillus saerimneri 30a (Formerly Lactobacillus sp. Strain 30a), a Reference Lactic Acid Bacterium Strain Producing Biogenic Amines

    NARCIS (Netherlands)

    Romano, Andrea; Trip, Hein; Campbell-Sills, Hugo; Bouchez, Olivier; Sherman, David; Lolkema, Juke S.; Lucas, Patrick M.

    2013-01-01

    Lactobacillus sp. strain 30a (Lactobacillus saerimneri) produces the biogenic amines histamine, putrescine, and cadaverine by decarboxylating their amino acid precursors. We report its draft genome sequence (1,634,278 bases, 42.6% G+C content) and the principal findings from its annotation, which mi

  18. HPLC quantification of biogenic amines in cheeses: correlation with PCR-detection of tyramine-producing microorganisms.

    Science.gov (United States)

    Fernández, María; Linares, Daniel M; Del Río, Beatriz; Ladero, Victor; Alvarez, Miguel A

    2007-08-01

    The consumption of food and beverages containing high amounts of biogenic amines (BA) can have toxicological effects. BA found in foods and beverages are synthesized by the microbial decarboxylation of certain amino acids. This paper reports the concentrations of BAs in a number of commercial cheeses, as determined by HPLC. The cheeses studied were made from raw and pasteurized milk of different origin, and were subjected to different ripening periods. BA concentrations were lower in short ripening period than in long ripening period cheeses, and higher in cheeses made from raw milk than in those made from pasteurized milk. The highest BA concentrations were recorded in blue cheeses made from raw milk. Tyramine was the most commonly recorded and abundant BA. The presence of tyramine-producing bacteria was determined by PCR, and a good correlation obtained between the results of this method and tyramine detection by HPLC. These methods could be used to complement one another in the detection and quantification of tyramine in cheese prevention of tyramine accumulation in cheese.

  19. Palladium nanoparticles produced by fermentatively cultivated bacteria as catalyst for diatrizoate removal with biogenic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hennebel, T.; Fitts, J.; Nevel, S. V.; Verschuere, S.; De Corte, S.; De Gusseme, B.; Cuvelier, C.; van der Lelie, D.; Boon, N.; Verstraete, W.

    2011-05-17

    A new biological inspired method to produce nanopalladium is the precipitation of Pd on a bacterium, i.e., bio-Pd. This bio-Pd can be applied as catalyst in dehalogenation reactions. However, large amounts of hydrogen are required as electron donor in these reactions resulting in considerable costs. This study demonstrates how bacteria, cultivated under fermentative conditions, can be used to reductively precipitate bio-Pd catalysts and generate the electron donor hydrogen. In this way, one could avoid the costs coupled to hydrogen supply. The catalytic activities of Pd(0) nanoparticles produced by different strains of bacteria (bio-Pd) cultivated under fermentative conditions were compared in terms of their ability to dehalogenate the recalcitrant aqueous pollutants diatrizoate and trichloroethylene. While all of the fermentative bio-Pd preparations followed first order kinetics in the dehalogenation of diatrizoate, the catalytic activity differed systematically according to hydrogen production and starting Pd(II) concentration in solution. Batch reactors with nanoparticles formed by Citrobacter braakii showed the highest diatrizoate dehalogenation activity with first order constants of 0.45 {+-} 0.02 h{sup -1} and 5.58 {+-} 0.6 h{sup -1} in batches with initial concentrations of 10 and 50 mg L{sup -1} Pd, respectively. Nanoparticles on C. braakii, used in a membrane bioreactor treating influent containing 20 mg L{sup -1} diatrizoate, were capable of dehalogenating 22 mg diatrizoate mg{sup -1} Pd over a period of 19 days before bio-Pd catalytic activity was exhausted. This study demonstrates the possibility to use the combination of Pd(II), a carbon source and bacteria under fermentative conditions for the abatement of environmental halogenated contaminants.

  20. Species of Staphylococcus and Bacillus isolated from traditional sausages as producers of biogenic amines.

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    Roberto eBermúdez

    2012-04-01

    Full Text Available Histidine, lysine, ornithine and tyrosine decarboxylase activities were tested in 38 strains of Staphylococcus (15 of Staph. equorum, 11 of Staph. epidermidis, 7 of Staph. saprophyticus, and 5 of Staph. pasteuri and 19 strains of Bacillus (13 of B. subtilis and 6 of B. amyloliquefaciens isolated from two Spanish traditional sausage varieties.The four decarboxylase activities were present in most of the strains studied, but some variability was observed between strains within each microbial species.Accumulation of putrescine and cadaverine was assessed in the culture media of the strains that displayed ornithine and lysine decarboxylase activities. The aminogenic potential of the strains was low, with amounts accumulated lower than 25 mg/L for the putrescine and than 5 mg/L for the cadaverine, with the exception of a strain of Staph. equorum that produced 1415 mg/L of putrescine, and of a strain of Staph. epidermidis that accumulated 977 mg/L of putrescine and 36 mg/L of cadaverine.

  1. Uraninite recrystallization and Pb loss in the Oklo and Bangombé natural fission reactors, Gabon

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    Evins, Lena Z.; Jensen, Keld A.; Ewing, Rodney C.

    2005-03-01

    The Oklo and Bangombé natural fossil fission reactors formed ca. 2 Ga ago in the Franceville basin, Gabon. The response of uraninite in the natural reactors to different geological conditions has implications for the disposal of the UO 2 in spent nuclear fuel. Uraninite and galena from two reactor zones, RZ16 at Oklo and RZB at Bangombé, were studied to clarify the chronology and effect of alteration events on the reactor zones. In addition, ion microprobe U-Pb analysis of zircons from a dolerite dyke in the Oklo deposit were completed to better constrain the age of the dyke, and thereby testing the link between the dyke and an important alteration event in the reactor zones. The analyzed uraninite from RZ16 and RZB contains ca. 6 wt% PbO, indicating a substantial loss of radiogenic Pb. Transmission electron microscopy showed that microscopic uraninite grains in the reactor zones consist of mainly defect-free nanocrystalline to microcrystalline aggregates. However, the nanocrystalline regions have elevated Si contents and lower Pb contents than coarser uraninite crystallites. Single stage model ages of large, millimeter-sized galena grains at both RZ16 and RZB correlate well with the age of the Oklo dolerite dyke, 860 ± 39 Ma (2σ). Thus, the first major Pb loss from uraninite occurred at both Oklo and Bangombé during regional extension and the intrusion of a dyke swarm in the Franceville basin, ˜860-890 Ma ago. Uraninite Pb isotopes from RZ16 and RZB give lower ages of ca. 500 Ma. These ages agree with the "chemical" ages of the uraninite, and show that an ancient Pb loss occurred after the intrusion of the dolerite dykes. The presence of nanocrystallites in the reactor uraninite indicates internal recrystallization, which may have occurred around 500 Ma, resulting in the 6wt% PbO uraninite. It is suggested that leaching by fluid interaction triggered by the Pan-African orogeny was important during this second Pb-loss event. Thus, there are indications that

  2. U and Pb isotope analysis of uraninite and galena by ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Evins, L.Z.; Sunde, T.; Schoeberg, H. [Swedish Museum of Natural History, Stockholm (Sweden). Laboratory for Isotope Geology; Fayek, M. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences

    2001-10-01

    Accurate isotopic analysis of minerals by ion microprobe, or SIMS (Secondary Ion Mass Spectrometry) usually requires a standard to correct for instrumental mass bias effects that occur during analysis. We have calibrated two uraninite crystals and one galena crystal to be used as ion probe standards. As part of this study we describe the analytical procedures and problems encountered while trying to establish fractionation factors for U and Pb isotopes measured in galena and uraninite. Only the intra-element isotopic mass fractionation is considered and not the interelement fractionation. Galena and uraninite were analysed with TIMS (Thermal Ionisation Mass Spectrometry) prior to SIMS. One uraninite crystal (P88) comes from Sweden and is ca 900 Ma old, the other from Maine, USA (LAMNH-30222) and is ca 350 Ma old. The galena sample comes from the Paleoproterozoic ore district Bergslagen in Sweden. SIMS analyses were performed at two different laboratories: the NORDSM facility in Stockholm, which has a high resolution Cameca IMS 1270 ion microprobe, and the Oak Ridge National Laboratory (ORNL) in Tennessee, which has a Cameca IMS 4f ion microprobe. The results show that during the analysis of galena, Pb isotopes fractionate in favour of the lighter isotope by as much as 0.5%/amu. A Pb isotope fractionation factor for uraninite was more difficult to calculate, probably due to the formation of hydride interferences encountered during analysis with the Cameca IMS 1270 ion microprobe. However, drying the sample in vacuum prior to analysis, and using high-energy filtering and a cold trap during analysis can minimise these hydride interferences. A large fractionation of U isotopes of ca 1.4%/amu in favour of the lighter isotope was calculated for uraninite.

  3. Comparison of γ-aminobutyric acid and biogenic amine content of different types of ewe’s milk cheese produced in Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    Gavina Manca

    2015-06-01

    Full Text Available The bioactive compounds γ-aminobutyric acid (GABA and biogenic amines (BA, together with protein-free amino acids, were measured by high-performance liquid chromatography in ewe’s milk cheeses produced in Sardinia with different technological traits. The study included three types of cheese: Pecorino Sardo PDO, Pecorino and Casu Marzu. Farmhouse Casu Marzu and Pecorino showed GABA content (maximum levels: 1001.3 and 378.1 mg 100 g–1 respectively that had never been found so high in cheese before, suggesting that these types of cheese present ideal conditions to produce GABA. These two types of cheese also showed high levels of BA (their total maximum levels were 1035.7 and 288.0 mg 100 g–1 respectively. Pearson correlation analysis detected significant correlation between GABA and the main BA present in the cheeses (tyramine, cadaverine and putrescine, suggesting that the factors affecting the production of GABA are the same as those influencing BA formation.

  4. Thermogenic and secondary biogenic gases, San Juan Basin, Colorado and New Mexico - Implications for coalbed gas producibility

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A.R.; Kaiser, W.R. (Univ. of Texas, Austin, TX (United States)); Ayers, W.B. Jr. (Taurus Exploration, Inc., Birmingham, AL (United States))

    1994-08-01

    The objectives of this paper are to (1) describe the types and the major components of coalbed gases, (2) evaluate the variability of Fruitland coalbed gas composition across the basin, (3) assess factors affecting coalbed gas origin and composition, (4) determine the timing and extent of gas migration and entrapment, and (5) suggest application of these results to coalbed gas producibility. Data from more than 750 Fruitland coalbed gas wells were used to make gas-composition maps and to evaluate factors controlling gas origin. The gas data were divided into overpressured, underpressured, and transitional categories based on regional pressure regime. Also, [delta][sup 13]C isotopic values from 41 methane, 7 ethane and propane, 13 carbon dioxide, and 10 formation-water bicarbonate samples were evaluated to interpret gas origin. The data suggests that only 25-50% of the gas produced in the high-productivity fairway was generated in situ during coalification. 82 refs., 14 figs., 3 tabs.

  5. Biogenic amines in fermented foods

    NARCIS (Netherlands)

    Spano, G.; Russo, P.; Lonvaud-Funel, A.; Lucas, P.; Alexandre, H.; Grandvalet, C.; Coton, E.; Coton, M.; Barnavon, L.; Bach, B.; Rattray, F.; Bunte, A.; Magni, C.; Ladero, V.; Alvarez, M.; Fernández, M.; Lopez, P.; Palencia, P.F. de; Corbi, A.; Trip, H.; Lolkema, J.S.

    2010-01-01

    Food-fermenting lactic acid bacteria (LAB) are generally considered to be non-toxic and non-pathogenic. Some species of LAB, however, can produce biogenic amines (BAs). BAs are organic, basic, nitrogenous compounds, mainly formed through decarboxylation of amino acids. BAs are present in a wide rang

  6. Biogenic amines in beer

    OpenAIRE

    Čiháková, Dagmar

    2016-01-01

    This thesis deals with the technological process of brewing beer, describes the raw materials needed for its production, and points out the useful and harmful substances contained in beer as biogenic amines (BA). Furthermore, there are described the issues of biogenic amines in food and primarily in beer, which is a histamine, putrescine, cadaverine, tyramine and tryptamine. In the practical section BA was determined in lager bottom-fermented beers from local microbreweries and large industri...

  7. Uranium isotopic data in uraninite spent fuel from the Bangombe natural nuclear reactor (Gabon) and its surroundings

    Science.gov (United States)

    Fernandez-Diaz; Quejido; Crespo; Perez del Villar L; Martin-Sanchez; Lozano

    2000-07-01

    In the framework of the "Oklo-Natural Analogue Phase II" Project, uraninite from the Bangombe natural reactor and samples from its host rock were analyzed to determine their uranium isotopic composition by thermal ionisation mass spectrometry, inductively coupled plasma mass spectrometry and alpha spectrometry. There were several objectives for this work: (i) to validate the 235U/238U isotopic ratios obtained by these techniques; (ii) to test the use of the 235U/238U ratio of uraninite as a tracer of migration/retention processes of uranium from the source term to the far field; (iii) to evaluate the most recent migration/retention processes of uranium in the system by U-series disequilibrium.

  8. Uranium isotopic data in uraninite spent fuel from the Bangombe natural nuclear reactor (Gabon) and its surroundings

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Diaz, M.; Quejido, A.J.; Crespo, M.T.; Villar, L.P. del; Martin-Sanchez, A. E-mail: ams@unex.es; Lozano, J.C

    2000-07-15

    In the framework of the 'Oklo-Natural Analogue Phase II' Project, uraninite from the Bangombe natural reactor and samples from its host rock were analyzed to determine their uranium isotopic composition by thermal ionisation mass spectrometry, inductively coupled plasma mass spectrometry and alpha spectrometry. There were several objectives for this work: (i) to validate the {sup 235}U/{sup 238}U isotopic ratios obtained by these techniques; (ii) to test the use of the {sup 235}U/{sup 238}U ratio of uraninite as a tracer of migration/retention processes of uranium from the source term to the far field; (iii) to evaluate the most recent migration/retention processes of uranium in the system by U-series disequilibrium.

  9. Groundwater chemistry of the Okélobondo uraninite deposit area (Oklo, Gabon): two-dimensional reactive transport modelling

    Science.gov (United States)

    Salas, J.; Ayora, C.

    2004-03-01

    The stability of uranium-bearing minerals in natural environments is of interest to evaluate the feasibility of radioactive waste repositories. The uraninite bodies, UO 2(s), in the Oklo district (Gabon) are the result of a natural fission process, which took place 1970 Ma ago. These deposits can be regarded as natural analogues for spent fuel. One of the uraninite bodies, the Okélobondo deposit, is located at a depth of 300 m. Groundwater samples from boreholes located at shallow depths (100-200 m) show neutral to basic pH, anoxic conditions (Eh=0.10 to -0.05 V) and are saturated with respect to uraninite. In contrast, deeper samples collected in the vicinity of the ore body are oxidising (Eh=0.32-0.47 V), slightly basic (pH=7.0-8.5) and undersaturated with respect to uraninite. These oxidising conditions at depth, if present under repository conditions, may affect the stability of uranium oxide. In order to improve our understanding of the observed site geochemistry, the available information on the lithology and groundwater flow was integrated in a reactive transport model. The chemical composition and the pH-Eh values of the water sampled above and in the western side of the Okélobondo deposit can be explained by the interaction of meteoric recharge with pelites, dolomites and sandstones. The dissolution of Fe(II)-silicates and the oxidation of the Fe(II)-aqueous species maintained the pH-Eh distribution along the Fe 2+-Fe(OH) 3(am) equilibrium, with the result that uraninite does not dissolve. This may explain the lower uranium content in the water samples from pelites and dolomites above the Okélobondo deposit. The high Mn/Fe ratio and the high pH-Eh values of the water sampled at depth, close to the Okélobondo deposit, suggest a control by the Mn 2+-MnOOH(s) equilibrium. This control is attributed to the dissolution of a large rhodochrosite, MnCO 3(s), and manganite, MnOOH(s) deposit in the recharge area on the eastern side.

  10. Groundwater chemistry of the Okélobondo uraninite deposit area (Oklo, Gabon): two-dimensional reactive transport modelling.

    Science.gov (United States)

    Salas, J; Ayora, C

    2004-03-01

    The stability of uranium-bearing minerals in natural environments is of interest to evaluate the feasibility of radioactive waste repositories. The uraninite bodies, UO2(s), in the Oklo district (Gabon) are the result of a natural fission process, which took place 1970 Ma ago. These deposits can be regarded as natural analogues for spent fuel. One of the uraninite bodies, the Okélobondo deposit, is located at a depth of 300 m. Groundwater samples from boreholes located at shallow depths (100-200 m) show neutral to basic pH, anoxic conditions (Eh = 0.10 to -0.05 V) and are saturated with respect to uraninite. In contrast, deeper samples collected in the vicinity of the ore body are oxidising (Eh = 0.32-0.47 V), slightly basic (pH = 7.0-8.5) and undersaturated with respect to uraninite. These oxidising conditions at depth, if present under repository conditions, may affect the stability of uranium oxide. In order to improve our understanding of the observed site geochemistry, the available information on the lithology and groundwater flow was integrated in a reactive transport model. The chemical composition and the pH-Eh values of the water sampled above and in the western side of the Okélobondo deposit can be explained by the interaction of meteoric recharge with pelites, dolomites and sandstones. The dissolution of Fe(II)-silicates and the oxidation of the Fe(II)-aqueous species maintained the pH-Eh distribution along the Fe(2+)-Fe(OH)3(am) equilibrium, with the result that uraninite does not dissolve. This may explain the lower uranium content in the water samples from pelites and dolomites above the Okélobondo deposit. The high Mn/Fe ratio and the high pH-Eh values of the water sampled at depth, close to the Okélobondo deposit, suggest a control by the Mn(2+)-MnOOH(s) equilibrium. This control is attributed to the dissolution of a large rhodochrosite, MnCO3(s), and manganite, MnOOH(s) deposit in the recharge area on the eastern side.

  11. Synthesis of hydroxyapatite from biogenic wastes

    Directory of Open Access Journals (Sweden)

    Teerawat Laonapakul

    2015-09-01

    Full Text Available Hydroxyapatite (HAp is a major component of human bone, teeth and hard tissue. It is one of only a few bioactive materials. Since HAp is the most widely used ceramic biomaterial, various techniques have been developed to synthesize HAp. In recent years, the use of natural biogenic structures and materials for medical proposes has been motivated by limitations in producing synthetic materials. This article mainly focuses on the use of biogenic wastes to prepare HAp. These include bio-wastes, marine corals, eggshells, seashells and bio-membranes. In the present review, useful information about HAp preparation methodologies has been summarized for further research and development.

  12. Biogenic amine content in dry fermented sausages as influenced by a producer, spice mix, starter culture, sausage diameter and time of ripening.

    Science.gov (United States)

    Komprda, T; Sládková, P; Dohnal, V

    2009-11-01

    Sixteen types of dry fermented sausages were commercially produced as combinations of two producers (designated K and R), two starter cultures (Pediococcus pentosaceus, C; Lactobacillus curvatus+Staphylococcus carnosus, F), two spicing mixtures (H; P) and two casing diameters (4.5cm, T; 7cm, W), and were sampled at days zero, 14, 28 (end of ripening), 49, 70, 91 and 112 (samples were stored at 15°C and relative humidity of 70% between days 28 and 112). Tyramine and putrescine content (Y, mgkg(-1)) increased (Psausages as compared to the W, H and F counterparts, respectively; content of both amines was lower (Psausages than in the R-sausages. Tyramine content in the sausages at the time interval 28days of ripening+21days of storage was in the range from 170 (KHCU sausage combination) to 382 (RHFS) mgkg(-1).

  13. The Potential of the Yeast Debaryomyces hansenii H525 to Degrade Biogenic Amines in Food

    Directory of Open Access Journals (Sweden)

    Mathias Bäumlisberger

    2015-11-01

    Full Text Available Twenty-six yeasts from different genera were investigated for their ability to metabolize biogenic amines. About half of the yeast strains produced one or more different biogenic amines, but some strains of Debaryomyces hansenii and Yarrowia lipolytica were also able to degrade such compounds. The most effective strain D. hanseniii H525 metabolized a broad spectrum of biogenic amines by growing and resting cells. Degradation of biogenic amines by this yeast isolate could be attributed to a peroxisomal amine oxidase activity. Strain H525 may be useful as a starter culture to reduce biogenic amines in fermented food.

  14. Biogenic Methane from Coal: The Oxidation Factor

    Science.gov (United States)

    Gallagher, L. K.; Glossner, A. W.; Landkamer, L.; Figueroa, L. A.; Mandernack, K. W.; Munakata Marr, J.

    2011-12-01

    Vast reserves of coal represent an untapped resource that can be used to produce methane gas, a cleaner energy alternative compared to standard fossil fuels. Microorganisms have demonstrated the ability to utilize coal as a carbon source, producing biogenic methane. With increasing demand for cleaner energy resources, understanding and enhancing biogenic methane production has become an area of active research. The conversion of coal to methane by microorganisms has been demonstrated experimentally by a number of research groups, but the state of the coal used as a substrate has not always been reported and may impact biogenic methane production. Microcosm experiments were designed in order to assess how the oxidation state of coal might influence methane production (e.g. as in a dewatered coal-bed natural gas system). Oxidized and un-oxidized coal samples from the Powder River Basin were incubated in microcosms inoculated with an enrichment culture that was derived from coal. Microcosms were characterized by headspace gas analysis, organic acid production, functional gene abundance (qPCR), and pyrosequencing of the 16S rRNA gene. Although the microbial consortium demonstrated the ability to utilize both oxidized and un-oxidized coal as a sole carbon source to generate methane, it was produced in higher quantities from the un-oxidized coal. This microbial community was dominated by Methanobacteriaceae (45%), epsilon-Proteobacteria (32%) and delta-Proteobacteria (13%). The results of this study provide a basis to develop strategies to enhance biogenic methane production from coal, as well as demonstrate the need for careful substrate preparation for inter-study comparisons.

  15. Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite

    Energy Technology Data Exchange (ETDEWEB)

    Veeramani, Harish; Scheinost, Andreas; Monsegue, Niven; Qafoku, Nikolla; Kukkadapu, Ravi K.; Newville, Mathew; Lanzirotti, Anthony; Pruden, Amy; Murayama, Mitsuhiro; Hochella, Michael F.

    2013-03-01

    During subsurface bioremediation of uranium-contaminated sites, indigenous metal and sulfate-reducing bacteria may utilize a variety of electron acceptors, including ferric iron and sulfate that could lead to the formation of various biogenic minerals in-situ. Sulfides, as well as structural and adsorbed Fe(II) associated with biogenic Fe(II)-sulfide phases, can potentially catalyze abiotic U6+ reduction via direct electron transfer processes. In the present work, the propensity of biogenic mackinawite (Fe1+xS, x = 0 to 0.11) to reduce U6+ abiotically was investigated. The biogenic mackinawite produced by Shewanella putrefaciens strain CN32 was characterized by employing a suite of analytical techniques including TEM, SEM, XAS and Mössbauer analyses. Nanoscale and bulk analyses (microscopic and spectroscopic techniques, respectively) of biogenic mackinawite after exposure to U6+ indicate the formation of nanoparticulate UO2. This study suggests the relevance of Fe(II) and sulfide bearing biogenic minerals in mediating abiotic U6+ reduction, an alternative pathway in addition to direct enzymatic U6+ reduction.

  16. The Experimental Study of Synthetic Octagonal Uraninite%八面体晶质铀矿的人工合成实验研究

    Institute of Scientific and Technical Information of China (English)

    沈才卿; 赵凤民

    2014-01-01

    介绍了人工合成八面体晶质铀矿的实验成果,并对合成的晶质铀矿样品进行了矿物学研究,获取了重要数据:合成的晶质铀矿样品最大颗粒为2.5 mm ×3.5 mm ,黑色到乌黑色,沥青光泽到半金属光泽,密度为8.87~9.12 g/cm3,反射光下为灰白色。实验表明,有利于晶质铀矿生长的条件是:强还原场、温度>450℃、压力>120 M Pa 、强酸性(pH <4)、稀溶液(铀含量小于23.8 mg/mL)。%The experiment result of octagonal crystal uraninite was introduced and their mineralogy fea-ture was studied in this paper .The shape of uraninite synthesized in the laboratory pressure vessel is with different size and combination shape .The most common combinations are tower ,ribs ,leaves and bran-ches .The biggest synthetic cristal of unaninite is 2 .5mm × 3 .5mm ,which is black to jet -black in color and asphlt to semi-metallic in luster and 8 .87 to 9 .12 g/cm3 in density .The favor sythetic condition for uraninite is :strong reducing field ,above temperature 450℃ ,above 120M Pa ,strong acid (pH < 4 ) ,( 23 .8 / ) .

  17. Biogenic amines formation in Streptococcus thermophilus isolated from home-made natural yogurt.

    Science.gov (United States)

    Gezginc, Yekta; Akyol, Ismail; Kuley, Esmeray; Özogul, Fatih

    2013-05-01

    Twelve different biogenic amines formation in 58 isolates of Streptococcus thermophilus from home-made natural yogurt were investigated in histidine (HDB) and lysine decarboxylase broth (LDB). All S. thermophilus isolates had an ability to produce twelve different biogenic amines in HDB and LDB. Most of the S. thermophilus isolates formed low amounts of histamine (1-50 mg/L) from histidine. Apart from one isolate, S. thermophilus produced tyramine at low (47 isolates) and medium (10 isolates) levels. The amount of each specific biogenic amine produced by S. thermophilus was generally lower than 100 mg L(-1). Also, the presence of hdcA gene was investigated using PCR technique and relation between gene and histamine production was conducted in S. thermophilus isolates. This study showed that most of the S. thermophilus isolates have the ability to form biogenic amines, especially histamine, and tyramine, which is an important consideration when selecting strains as starter cultures.

  18. Biogenic amines in smear and mould-ripened cheeses

    Directory of Open Access Journals (Sweden)

    Pavel Pleva

    2014-02-01

    Full Text Available The aim of the study was the monitoring of six biogenic amines (histamine, tyramine, phenylethylamine, tryptamine, putrescine, and cadaverine and two polyamines (spermidine and spermine in 30 samples of dairy products purchased in the Czech Republic, namely in 15 samples of mould-ripened cheeses and in 15 samples of smear-ripened cheeses. A further goal was the microbiological analysis of the individual samples of cheeses (total count of microorganisms, number of enterobacteria, enterococci, lactic acid bacteria, yeasts and moulds. The monitored biogenic amines were analyzed by a high performance liquid chromatography equipped with a UV/VIS DAD detector. The amount of enterobacteria in fresh cheese exceeded 105 CFU.g‑1. In smear-ripened cheese flavourless (Romadur type, the amount was >103 CFU.g-1 and 104-105 CFU.g-1 in smear-ripened cheese with flavour. Biogenic amines were observed in two groups of blue cheeses (white veined cheese and blue veined cheese and smear-ripened cheeses. In both groups, there is a possibility of the presence of biogenic amines because the number of microorganisms and concentration of free amino acids increase during ripening. In ten samples of soft smear-ripening acid cheese and in smear-ripened cheese, the total content of biogenic amines were 22-1000 mg.kg-1 and in 5 samples of these cheeses, it was in range 1000-6000 mg.kg-1. The total amount of biogenic amines in the blue cheeses were in range 40-600 mg.kg-1. The presense of the tyramine was observed in the all analysed cheeses. The tyramine producing strains generated more than 900 mg.kg-1 of this biogenic amine. The production of tryptamine in the analysed cheeses was not proved by this study. The results of this study show that biogenic amines and polyamines are common in cheese. However, in some cases, they can pose a significant health danger for consumers. Any legislative control authority does not monitor them, as they are secondary metabolites even

  19. Dry fermented sausages of Southern Italy: a comparison of free amino acids and biogenic amines between industrial and homemade products.

    Science.gov (United States)

    Leggio, Antonella; Belsito, Emilia L; De Marco, Rosaria; Di Gioia, Maria L; Liguori, Angelo; Siciliano, Carlo; Spinella, Mariagiovanna

    2012-04-01

    This paper compares some important parameters and the free amino acid and biogenic amine contents of cured industrial and homemade meat products. To this aim, industrial and homemade "soppressata" and "salsiccia", typical dry fermented sausages produced in Southern Italy, were analyzed. The homemade sausages showed a higher level of free biogenic amines than that manufactured industrially, most likely because biogenic amine formation in industrial products is limited by the use of starter cultures. The industrial sausages are characterized by a higher total free amino acid content than the homemade products. Overall, free amino acid and biogenic amine contents demonstrated that appreciable differences exist between homemade and industrial sausages.

  20. Occurrence of biogenic amines in Miso, Japanese traditional fermented soybean paste.

    Science.gov (United States)

    Byun, Bo Young; Mah, Jae-Hyung

    2012-12-01

    The objective of this study was to analyze overall contents of biogenic amines in Miso and thereby evaluate the safety of the food. Through HPLC analysis of 22 different Miso products, it was found that most samples had low biogenic amine contents. However, some samples contained both histamine and tyramine close to hazardous levels of the amines, which indicate that the amounts of biogenic amines in Miso are not completely within the safe level for human health. Meanwhile, the biogenic amine contents showed no clear relationship with physicochemical parameters, whereas they revealed a good relationship with the ratio of soybean to other grains used in raw material. Thus, it turned out that biogenic amine contents in Miso are primarily affected by the ratio of raw ingredients, especially soybeans. The aerobic plate counts of Miso samples ranged from 3 to 8 Log CFU/g, and all the strains isolated from Miso samples were found to produce biogenic amines. Most strains were identified to be Bacillus subtilis, often regarded as the predominant contaminant bacteria in Miso, and highly capable of producing tyramine and spermine. Taken together, therefore, this study suggests that variability of biogenic amine contents in Miso are primarily attributed to the ratio of raw ingredients in the food that affects the relative contribution level of bacterial contaminants to the contents.

  1. A new test procedure for biogenic sulfuric acid corrosion of concrete

    Science.gov (United States)

    Vincke; Verstichel; Monteny; Verstraete

    1999-01-01

    A new test method is described for biogenic sulfuric acid corrosion of concrete, more specifically in sewer conditions. The aim of the new test method is the development of an accelerated and reproducible procedure for monitoring the resistance of different types of concrete with regard to biogenic sulfuric acid corrosion. This experimental procedure reflects worst case conditions by providing besides H2S, also an enrichment of thiobacilli and biologically produced sulfur. By simulating the cyclic processes occurring in sewer pipes, significant differences between concrete mixtures could be detected after 51 days. Concrete modified by a styrene-acrylic ester polymer demonstrated a higher resistance against biogenic sulfuric acid attack.

  2. Subsurface Uranium Fate and Transport: Integrated Experiments and Modeling of Coupled Biogeochemical Mechanisms of Nanocrystalline Uraninite Oxidation by Fe(III)-(hydr)oxides - Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peyton, Brent M. [Montana State Univ., Bozeman, MT (United States); Timothy, Ginn R. [Univ. of California, Davis, CA (United States); Sani, Rajesh K. [South Dakota School of Mines and Technology, Rapid City, SD (United States)

    2013-08-14

    Subsurface bacteria including sulfate reducing bacteria (SRB) reduce soluble U(VI) to insoluble U(IV) with subsequent precipitation of UO2. We have shown that SRB reduce U(VI) to nanometer-sized UO2 particles (1-5 nm) which are both intra- and extracellular, with UO2 inside the cell likely physically shielded from subsequent oxidation processes. We evaluated the UO2 nanoparticles produced by Desulfovibrio desulfuricans G20 under growth and non-growth conditions in the presence of lactate or pyruvate and sulfate, thiosulfate, or fumarate, using ultrafiltration and HR-TEM. Results showed that a significant mass fraction of bioreduced U (35-60%) existed as a mobile phase when the initial concentration of U(VI) was 160 µM. Further experiments with different initial U(VI) concentrations (25 - 900 M) in MTM with PIPES or bicarbonate buffers indicated that aggregation of uraninite depended on the initial concentrations of U(VI) and type of buffer. It is known that under some conditions SRB-mediated UO2 nanocrystals can be reoxidized (and thus remobilized) by Fe(III)-(hydr)oxides, common constituents of soils and sediments. To elucidate the mechanism of UO2 reoxidation by Fe(III) (hydr)oxides, we studied the impact of Fe and U chelating compounds (citrate, NTA, and EDTA) on reoxidation rates. Experiments were conducted in anaerobic batch systems in PIPES buffer. Results showed EDTA significantly accelerated UO2 reoxidation with an initial rate of 9.5 M day-1 for ferrihydrite. In all cases, bicarbonate increased the rate and extent of UO2 reoxidation with ferrihydrite. The highest rate of UO2 reoxidation occurred when the chelator promoted UO2 and Fe(III) (hydr)oxide dissolution as demonstrated with EDTA. When UO2 dissolution did not occur, UO2 reoxidation likely proceeded through an aqueous Fe(III) intermediate as observed for both NTA and

  3. Intolerance to dietary biogenic amines: A review

    NARCIS (Netherlands)

    Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

  4. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

    Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

  5. Biogenic amines degradation by malolactic bacteria: towards a potential application in wine

    Directory of Open Access Journals (Sweden)

    Vittorio eCapozzi

    2012-04-01

    Full Text Available Biogenic amines in wine represent a toxicological risk for the health of the consumer, with several trade implications. In this study 26 strains of Lactobacillus plantarum were analysed for their ability to degrade biogenic amines commonly found during wine fermentation. Two strains of L. plantarum were selected in reason of their ability to degrade putrescine and tyramine. The degradation was assessed in vitro, both in presence of the biogenic amines and in presence of the specific chemical precursor and of producer bacteria. The two L. plantarum biotypes were found capable to work synergically. In addition, the survival in wine-like medium and the aptitude to degrade malic acid after alcoholic fermentation of the selected L. plantarum strains was analysed. Our results suggest the potential application of wine L. plantarum strains to design malolactic starter cultures able to degrade biogenic amines in wine.

  6. Study on biogenic amines in various dry salted fish consumed in China

    Science.gov (United States)

    Wu, Yanyan; Chen, Yufeng; Li, Laihao; Yang, Xianqing; Yang, Shaoling; Lin, Wanling; Zhao, Yongqiang; Deng, Jianchao

    2016-08-01

    This study was carried out to investigate the biogenic amines (BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine (CAD) and putrescine (PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret ( Pampus argenteus) (347.79 mg kg-1). Five of forty three samples exceeded the acceptable content of TYR (100 mg kg-1), and 23.26% of dried-salted fish contained high contents of biogenic amines (above 600 mg kg-1). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count (TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.

  7. Biogenic amines in italian pecorino cheese.

    Science.gov (United States)

    Schirone, Maria; Tofalo, Rosanna; Visciano, Pierina; Corsetti, Aldo; Suzzi, Giovanna

    2012-01-01

    The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations, and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (∼62.000t of production in 2010). Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or pasteurized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA). Bacterial amino acid decarboxylase activity and BA content have to be investigated within the complex microbial community of raw milk cheese for different cheese technologies. The results emphasize the necessity of controlling the indigenous bacterial population responsible for high production of BA and the use of competitive adjunct cultures could be suggested. Several factors can contribute to the qualitative and quantitative profiles of BA's in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, water activity, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge), and the presence of cofactor (pyridoxal phosphate, availability of aminases and deaminases). In fact physico-chemical parameters seem to favor biogenic amine-positive microbiota; both of these environmental factors can easily be modulated, in order to control growth of undesirable microorganisms. Generally, the total content of BA's in Pecorino cheeses can range from about 100-2400

  8. Managing your wine fermentation to reduce the risk of biogenic amine formation

    Directory of Open Access Journals (Sweden)

    Anita Yolandi Smit

    2012-03-01

    Full Text Available Biogenic amines are nitrogenous organic compounds produced in wine from amino acid precursors mainly by microbial decarboxylation. The concentration of biogenic amines that can potentially be produced is dependent on the amount of amino acid precursors in the medium, the presence of decarboxylase positive microorganisms and conditions that enable microbial or biochemical activity such as the addition of nutrients to support the alcoholic and malolactic fermentation (MLF inoculated starter cultures. MLF can be conducted using co-inoculation or inoculated after the completion of alcoholic fermentation (AF that may also affect the level of biogenic amine in the wine. This study focussed on the impact the addition of complex commercial yeast and bacterial nutrients and the use of different MLF inoculation scenarios could have on the production of biogenic amine in the wine. Results obtained with wine showed that in this study the amine that was influenced by nutrient addition was histamine. In the synthetic winemaking using 12 different treatments no clear tendencies were observed. It was shown that in certain conditions co-inoculation could reduce the amount of biogenic amines produced.

  9. Observations of oxidation products above a forest imply biogenic emissions of very reactive compounds

    Directory of Open Access Journals (Sweden)

    R. Holzinger

    2005-01-01

    Full Text Available Vertical gradients of mixing ratios of volatile organic compounds have been measured in a Ponderosa pine forest in Central California (38.90° N, 120.63° W, 1315m. These measurements reveal large quantities of previously unreported oxidation products of short lived biogenic precursors. The emission of biogenic precursors must be in the range of 13-66µmol m-2h-1 to produce the observed oxidation products. That is 6-30 times the emissions of total monoterpenes observed above the forest canopy on a molar basis. These reactive precursors constitute a large fraction of biogenic emissions at this site, and are not included in current emission inventories. When oxidized by ozone they should efficiently produce secondary aerosol and hydroxyl radicals.

  10. Biogenic silicate accumulation in sediments, Jiaozhou Bay

    Institute of Scientific and Technical Information of China (English)

    LI Xuegang; SONG Jinming; DAI Jicui; YUAN Huamao; LI Ning; LI Fengye; SUN Song

    2006-01-01

    It has been widely recognized that low silicate content in seawater is a major limiting factor to phytoplankton primary production in Jiaozhou Bay. However the reason of Si-limitation remains poorly understood. In the present study we measured the biogenic silicate content and discussed the accumulation of silicate in Jiaozhou Bay sediment. The results show that the biogenic silica content in the sediment of the Jiaozhou Bay is obviously much higher than those in the Yellow Sea and the Bohai Sea. The BSi:TN ratios and BSi:16P ratios in the sediment are > 1 and the OC:BSi ratio in sediment is lower than these of Redfield ratio (106:16), indicating that the decomposition rate of OC is much higher than that for BSi in similar conditions. Therefore, the majority of the biogenic silicate was buried and thus did not participate in silicate recycling. Silicate accumulation in sediment may explain why Si limits the phytoplankton growth in the Jiaozhou Bay. Comparing the flux of biogenic silicate from sediments with primary production rate, it can be concluded that only 15.5% of biogenic silicate is hydrolyzed during the journey from surface to bottom in seawater, thus approximate 84.5% of biogenic silicate could reach the bottom. The silicate releasing rate from the sediment to seawater is considerably lower than that of sedimentation of biogenic silicate, indicating silicate accumulation in sediment too. In a word, the silicate accumulation in sediment is the key reason of silicate limiting to phytoplankton growth in Jiaozhou Bay.

  11. Presence of uraninite associated with copper and iron minerals in the region of the Serra do Sossego, north of Brazil; Presenca de uraninita associada a minerais de cobre e ferro na regiao da Serra do Sossego, norte do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Salas, Humberto Terrazas; Murta, Clecio Campi [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: salasht@urano.cdtn.br; Nalini Junior, Herminio Arias [Ouro Preto Univ., MG (Brazil). Escola de Minas. Dept. de Geologia

    2000-07-01

    In this work, results on studies carried out on radioactive samples from Serra do Sossego (close to Carajas , in the state of Para) are reported. According to studies of mineralogical characterization, involving petrographic and mineralographic analysis, complemented by other specific techniques, it was possible to determine the forms of presentation of the uraninite (UO{sub 2}), and its respective association to sulphide minerals rich in copper, primarily those with greater concentration, such as bornite (Cu{sub 5}FeS{sub 4}) and, secondarily, calcopirite (CuFeS{sub 2}). These sulphides come associated to abundant iron oxide, such as magnetite (Fe{sub 3}O{sub 4}) and its alteration products, and also assorted silicate minerals. From the results of autoradiographic tests and an electronic microprobe, a significant amount of uraninite was determined, showing that sulfites and oxides that occur associated to the uranium mineral, include this element in their crystalline lattices. (author)

  12. Microwave sintering of biogenic hydroxyapatite ceramics for reconstructive surgery

    Directory of Open Access Journals (Sweden)

    Hanna Tovstonoh

    2014-03-01

    Full Text Available Ceramics based on biogenic hydroxyapatite have been produced via a microwave sintering at 1000 °C for 5, 10, 15, 20 and 30 min. It was shown that all of the ceramics studied exhibit volumetric shrinkage (2.3–4.6 %, which increases with increasing sintering time at maximum temperature. It was established that the total porosity did not depend on sintering time at 1000 °C and was equal to 38–40 %. Moreover, in all of the materials an open porosity dominated. The ultimate compression strength was in the range 35–40 MPa.

  13. BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2015-02-01

    Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

  14. Biogenic amines in raw and processed seafood

    Directory of Open Access Journals (Sweden)

    Pierina eVisciano

    2012-06-01

    Full Text Available The presence of biogenic amines in raw and processed seafood, associated with either time/temperature conditions or food technologies is discussed in the present paper from a safety and prevention point of view. In particular, storage temperature, handling practices, presence of microbial populations with decarboxylase activity and availability of free amino acids are considered the most important factors affecting the production of biogenic amines in raw seafood. On the other hand, some food technological treatments such as salting, ripening, fermentation or marination can increase the levels of biogenic amines in processed seafood. The consumption of high amount of biogenic amines, above all histamine, can result in food borne poisoning which is a worldwide problem. The European Regulation established as maximum limits for histamine, in fishery products from fish species associated with high histidine amounts, values ranging from 100 to 200 mg/kg, while for products which have undergone enzyme maturation treatment in brine, the aforementioned limits rise to 200 and 400 mg/kg. Preventive measures and emerging methods aiming at controlling the production of biogenic amines are also reported for potential application in seafood industries.

  15. Forensic differentiation of biogenic organic compounds from petroleum hydrocarbons in biogenic and petrogenic compounds cross-contaminated soils and sediments.

    Science.gov (United States)

    Wang, Zhendi; Yang, C; Kelly-Hooper, F; Hollebone, B P; Peng, X; Brown, C E; Landriault, M; Sun, J; Yang, Z

    2009-02-13

    "Total petroleum hydrocarbons" (TPHs) or "petroleum hydrocarbons" (PHCs) are one of the most widespread soil pollutants in Canada, North America, and worldwide. Clean-up of PHC-contaminated soils and sediments costs the Canadian economy hundreds of million of dollars annually. Much of this activity is driven by the need to meet regulated levels of PHC in soil. These PHC values are legally required to be assessed using standard methods. The method most commonly used in Canada, specified by the Canadian Council of Ministers of the Environment (CCME), measures the total hydrocarbon concentrations in a soil by carbon range (Fraction 1: C(6)-C(10); Fraction 2: C(10)-C(16), Fraction 3: C(16)-C(34): and Fraction 4: C(34)+). Using the CCME method, all of the materials extractible by a mixture of 1:1 hexane:acetone are considered to be petroleum hydrocarbon contaminants. Many hydrocarbon compounds and other extractible materials in soil, however, may originate from non-petroleum sources. Biogenic organic compounds (BOCs) is a general term used to describe a mixture of organic compounds, including alkanes, sterols and sterones, fatty acids and fatty alcohols, and waxes and wax esters, biosynthesized by living organisms. BOCs are also produced during the early stages of diagenesis in recent aquatic sediments. BOC sources could include vascular plants, algae, bacteria and animals. Plants and algae produce BOCs as protective wax coating that are released back into the sediment at the end of their life cycle. BOCs are natural components of thriving plant communities. Many solvent-extraction methods for assessing soil hydrocarbons, however, such as the CCME method, do not differentiate PHCs from BOCs. The naturally occurring organics present in soils and wet sediments can be easily misidentified and quantified as regulated PHCs during analysis using such methods. In some cases, biogenic interferences can exceed regulatory levels, resulting in remediation of petroleum impacts that

  16. Additional studies on mixed uranyl oxide-hydroxide hydrate alteration products of uraninite from the palermo and ruggles granitic pegmatites, grafton county, New Hampshire

    Science.gov (United States)

    Foord, E.E.; Korzeb, S.L.; Lichte, F.E.; Fitzpatrick, J.J.

    1997-01-01

    Additional studies on an incompletely characterized secondary uranium "mineral" from the Ruggles and Palermo granitic pegmatites, New Hampshire, referred to as mineral "A" by Frondel (1956), reveal a mixture of schoepite-group minerals and related uranyl oxide-hydroxide hydrated compounds. A composite chemical analysis yielded (in wt.%): PbO 4.85 (EMP), UO3 83.5 (EMP), BaO 0.675 (av. of EMP and ICP), CaO 0.167 (av. of EMP and ICP), K2O 2.455 (av. of EMP and ICP), SrO 0.21 (ICP), ThO2 0.85 (ICP), H2O 6.9, ??99.61. Powder-diffraction X-ray studies indicate a close resemblance in patterns between mineral "A" and several uranyl oxide-hydroxide hydrated minerals, including the schoepite family of minerals and UO2(OH)2. The powder-diffraction data for mineral "A" are most similar to those for synthetic UO2.86??1.5H2O and UO2(OH)2, but other phases are likely present as well. TGA analysis of both mineral "A" and metaschoepite show similar weight-loss and first derivative curves. The dominant losses are at 100??C, with secondary events at 400?? and 600??C. IR spectra show the presence of (OH) and H2O. Uraninite from both pegmatites, analyzed by LAM-ICP-MS, shows the presence of Th, Pb, K and Ca.

  17. Biogenic amines in Italian Pecorino cheese

    Directory of Open Access Journals (Sweden)

    Maria eSchirone

    2012-05-01

    Full Text Available The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (approximately 53.727t of production. Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or thermized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA. Several factors can contribute to the qualitative and quantitative profiles of BA’s in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, aw, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge and the presence of cofactor. Generally, the total content of BA’s can range from about 100-2400 mg/kg, with a prevalence of toxicologically important BA’s, tyramine and histamine. The presence of BA in Pecorino cheeses is becoming increasingly important to consumers and cheese-maker alike, due to the potential threats of toxicity to humans and consequent trade implications.

  18. Seasonal trends of biogenic terpene emissions.

    Science.gov (United States)

    Helmig, Detlev; Daly, Ryan Woodfin; Milford, Jana; Guenther, Alex

    2013-09-01

    Biogenic volatile organic compound (BVOC) emissions from six coniferous tree species, i.e. Pinus ponderosa (Ponderosa Pine), Picea pungens (Blue Spruce), Pseudotsuga menziesii (Rocky Mountain Douglas Fir) and Pinus longaeva (Bristlecone Pine), as well as from two deciduous species, Quercus gambelii (Gamble Oak) and Betula occidentalis (Western River Birch) were studied over a full annual growing cycle. Monoterpene (MT) and sesquiterpene (SQT) emissions rates were quantified in a total of 1236 individual branch enclosure samples. MT dominated coniferous emissions, producing greater than 95% of BVOC emissions. MT and SQT demonstrated short-term emission dependence with temperature. Two oxygenated MT, 1,8-cineol and piperitone, were both light and temperature dependent. Basal emission rates (BER, normalized to 1000μmolm(-2)s(-1) and 30°C) were generally higher in spring and summer than in winter; MT seasonal BER from the coniferous trees maximized between 1.5 and 6.0μgg(-1)h(-1), while seasonal lows were near 0.1μgg(-1)h(-1). The fractional contribution of individual MT to total emissions was found to fluctuate with season. SQT BER measured from the coniferous trees ranged from temperature dependence in emissions modeling, was not found to exhibit discernible growth season trends. A seasonal correction factor proposed by others in previous work to account for a sinusoidal shaped emission pattern was applied to the data. Varying levels of agreement were found between the data and model results for the different plant species seasonal data sets using this correction. Consequently, the analyses on this extensive data set suggest that it is not feasible to apply a universal seasonal correction factor across different vegetation species. A modeling exercise comparing two case scenarios, (1) without and (2) with consideration of the seasonal changes in emission factors illustrated large deviations when emission factors are applied for other seasons than those in which

  19. Biogenic metals in advanced water treatment.

    Science.gov (United States)

    Hennebel, Tom; De Gusseme, Bart; Boon, Nico; Verstraete, Willy

    2009-02-01

    Microorganisms can change the oxidation state of metals and concomitantly deposit metal oxides and zerovalent metals on or into their cells. The microbial mechanisms involved in these processes have been extensively studied in natural environments, and researchers have recently gained interest in the applications of microbe-metal interactions in biotechnology. Because of their specific characteristics, such as high specific surface areas and high catalytic reactivity, biogenic metals offer promising perspectives for the sorption and (bio)degradation of contaminants. In this review, the precipitation of biogenic manganese and iron species and the microbial reduction of precious metals, such as palladium, platinum, silver and gold, are discussed with specific attention to the application of these biogenic metals in innovative remediation technologies in advanced water treatment.

  20. Biogenic crust dynamics on sand dunes

    CERN Document Server

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

    Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fixed crusted dunes and fixed vegetated dunes at low wind power, and fixed vegetated dunes and active dunes at high wind power. These results suggest a cross-over between two different forms of desertification.

  1. Melatonin is formed during winemaking at safe levels of biogenic amines.

    Science.gov (United States)

    Rodriguez-Naranjo, M Isabel; Ordóñez, José L; Callejón, Raquel M; Cantos-Villar, Emma; Garcia-Parrilla, M Carmen

    2013-07-01

    The European Food Safety Authority (EFSA) has accepted health claims for the food constituent melatonin because scientific evidence shows that it is effective at reducing sleep onset latency, and that it alleviates subjective feelings of jet lag. According to risk assessment data published by EFSA in 2011, histamine and tyramine are the most toxic biogenic amines and the ones that most affect food safety. The potential formation of biogenic amines is a concern in fermented foods because of the intense microbial activity. Conversely, Saccharomyces cerevisiase produces melatonin during fermentation in the winemaking process. This study aims to evaluate the production of potentially healthy melatonin and toxic biogenic amines during the winemaking process. To this end, 11 biogenic amines (agmatine, cadaverine, histamine, methylamine, 2-phenylethylamine, putrescine, spermidine, spermine, tyramine, tryptamine and melatonin) have been monitored during the making of 5 monovarietal wines (Merlot, Palomino Fino, Syrah, Tempranillo and Tintilla de Rota). This paper shows that alcoholic and malolactic fermentation plays a crucial role in the formation of these compounds. Bioactive melatonin is formed at safe levels of the other biogenic amines.

  2. Formation and occurrence of biogenic iron-rich minerals

    Science.gov (United States)

    Fortin, Danielle; Langley, Sean

    2005-09-01

    Iron cycling in the Earth's crust depends on redox reactions, which often trigger the precipitation and dissolution of Fe-rich minerals. Microbial activity is also an integral part of iron cycling, through carbon fixation, respiration and passive sorption reactions. Iron oxides formed in close association with bacteria (either as internal or external precipitates) are referred to as biogenic minerals. They form in several types of environments on Earth, from freshwater to marine systems, aquifers, soils and mining impacted systems. Biogenic iron oxides generally occur as nanocrystals and show a wide range of morphology and mineralogy. These minerals form as a result of the direct metabolic activity of bacteria or as a result of passive sorption and nucleation reactions. The metabolic activity of acidophilic and neutrophilic iron-oxidizing bacteria under oxic conditions promotes the oxidation of Fe(II) to Fe(III) and the precipitation of biogenic iron oxides as extracellular precipitates near or on the bacterial cells. Iron oxidation under anoxic conditions can also occur, as a result of the activity of nitrate-reducers and photoautotrophic bacteria using Fe(II) as an electron donor. Secondary Fe-oxide formation has been reported during the microbial reduction of iron oxides. Passive Fe sorption and nucleation onto bacterial cell walls represents another important mechanism leading to iron oxide formation. The surface reactivity of the bacterial surface under environmental pH conditions confers a net negative charge to the cell wall, which leads to the binding of soluble iron and eventually to the precipitation of iron oxides under saturation conditions. Extracellular polymers produced by bacteria can act as a template for iron sorption and Fe-oxide nucleation. Intracellular iron oxide formation has been observed in natural environments. Magnetotactic bacteria produce intracellular magnetosomes, occurring as chains of magnetite crystals within the cells, and an

  3. Organosulfate Formation in Biogenic Secondary Organic Aerosol

    Science.gov (United States)

    Organosulfates of isoprene, α-pinene, and β-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive seri...

  4. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Glasauer, Susan; Korenevsky, Anton; Ferris, F. Grant

    2000-08-08

    The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  5. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    2001-08-15

    The overall purpose of the project was to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addressed how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  6. Grain coarsening of calcite: Fundamental mechanisms and biogenic inhibition

    DEFF Research Database (Denmark)

    Schultz, Logan Nicholas

    In a saturated solution, submicrometer calcite (CaCO3) crystals recrystallize and coarsen to minimize surface area. The thermodynamic driving force is described by the Gibbs-Thomson equation, but the rates and mechanism are poorly understood. Calcite grain coarsening has many implications...... in industry and nature, but the specific focus of this research project was to understand how small, biogenic calcite particles in chalk have resisted grain coarsening for over 60 million years in saturated reservoir fluids. A new method was developed to produce pure calcite powder that has submicrometer...... coarsening – small grains coarsen by aggregation at high temperatures, followed by Ostwald ripening. Alginate, a model for the acidic polysaccharides produced by coccolithiphores, inhibited coarsening at a steady rate. A Pseudomonas aeruginosa biofilm preserved particles for at least 60 days before...

  7. Technological factors affecting biogenic amine content in foods: a review

    Directory of Open Access Journals (Sweden)

    Fausto Gardini

    2016-08-01

    Full Text Available Biogenic amines (BAs are molecules which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine and agmatine. The importance of preventing the excessive accumulation of BAs in food is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BA accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting biogenic amine content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity and other BAs, environmental factors influencing BA formation (temperature, salt concentration, pH. In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolising BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances are addressed.

  8. A biogenic volatile organic compounds emission inventory for Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-hui; BAI Yu-hua; ZHANG Shu-yu

    2005-01-01

    The first detailed inventory for volatile organic compounds(VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing(RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVl) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km × 5 km and a time resolution of 1 h.Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 × 1012 gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 × 1011 gCfor isoprene, 2.1 × 1011 gC for monoterpenes, and 2.6 × 1011 gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study.

  9. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    1999-06-01

    The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals, and the impact of these processes on the solubility of metal contaminants, e.g., uranium, chromium and nickel. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  10. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    DAI JinXing; MI JingKui; LI ZhiSheng; HU AnPing; YANG Chun; ZHOU QingHua; SHUAI YanHua; ZHANG Ying; MA ChengHua; ZOU CaiNeng; ZHANG ShuiChang; LI Jian; NI YunYan; HU GuoYi; LUO Xia; TAO ShiZhen; ZHU GuangYou

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and cliche values of abiogenic and biogenic (referring to the therrnogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2)Abiogenic alkane gases have a carbon isotopic reversal trend (Δ13c1>Δ13c2>Δ13c3>Δ13c4) with Δ13c1>-30‰ in general; 3) Gases with R/Ra>0.5 and Δ13c1- Δ13c2>0 are of abiogenic origin; 4) Gases (methane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  11. Cytotoxicity and genotoxicity of biogenic silver nanoparticles

    Science.gov (United States)

    Lima, R.; Feitosa, L. O.; Ballottin, D.; Marcato, P. D.; Tasic, L.; Durán, N.

    2013-04-01

    Biogenic silver nanoparticles with 40.3 ± 3.5 nm size and negative surface charge (- 40 mV) were prepared with Fusarium oxysporum. The cytotoxicity of 3T3 cell and human lymphocyte were studied by a TaliTM image-based cytometer and the genotoxicity through Allium cepa and comet assay. The results of BioAg-w (washed) and BioAg-nw (unwashed) biogenic silver nanoparticles showed cytotoxicity exceeding 50 μg/mL with no significant differences of response in 5 and 10 μg/mL regarding viability. Results of genotoxicity at concentrations 5.0 and 10.0 ug/mL show some response, but at concentrations 0.5 and 1.0 μg/mL the washed and unwashed silver nanoparticles did not present any effect. This in an important result since in tests with different bacteria species and strains, including resistant, MIC (minimal inhibitory concentration) had good answers at concentrations less than 1.9 μg/mL. This work concludes that biogenic silver nanoparticles may be a promising option for antimicrobial use in the range where no cyto or genotoxic effect were observed. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other cells.

  12. Rett syndrome - Stimulation of endogenous biogenic amines

    Science.gov (United States)

    Pelligra, R.; Norton, R. D.; Wilkinson, R.; Leon, H. A.; Matson, W. R.

    1992-01-01

    Transient hypercapnic hyperoxemia was induced in two Rett syndrome children by the administration of a gaseous mixture of 80 percent O2 and 20 percent CO2. Time course studies of neurotransmitters and their metabolites showed an immediate and marked increase in central biogenic amine turnover following inhalation of the gas mixture. The increased turnover of biogenic amines was associated with improved clinical changes. This suggests a coupled relationship and provides further support for an etiological role of neurotransmitter dysfunction in Rett syndrome. In a complementary study, elevation of pulmonary CO2 by application of a simple rebreathing device resulted in improvement of abnormal blood gases and elimination of the Cheyne-Stokes-like respiratory pattern of the Rett syndrome. Near normalization of the EEG occurred when a normal respiratory pattern was imposed by means of a respirator. Taken together, these results lead to the preliminary conclusion that cerebral hypoxemia secondary to abnormal respiratory function may contribute to diminished production of biogenic amines in Rett syndrome.

  13. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and CH4/3He values of abiogenic and biogenic (referring to the thermogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2) Abiogenic alkane gases have a carbon isotopic reversal trend (δ 13C1> δ 13C2> δ 13C3> δ 13C4) with δ 13C1>-30‰ in general; 3) Gases with R/Ra >0.5 and δ 13C11 δ 13C2>0 are of abiogenic origin; 4) Gases (meth- ane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  14. [The content of biogenic amines in canned fish from the Turkish market].

    Science.gov (United States)

    Erkan, N; Helle, N; Ozden, O

    2001-01-01

    This paper describes the determination of biogenic amines in a number of canned fish of the Turkish market by means of HPLC. Over all 39 cans of sardine, tuna, sardel, mackerel, pelamide and trout were tested. The determination of agmatine, cadaverine, histamine, putrescine and tyramine was performed by HPLC with post column derivatization with ortho-phthaldialdehyde. Four samples contained higher amounts of biogenic amines (three sardine samples contained more than 1000 mg/kg histamine) while all other samples were acceptable. These results demonstrate the need of instrumental analyses in the quality control system of Turkish producers of canned fish. The quality of the products at least of some producers has to be improved, e.g. by cooperation between the official food control and the quality assurance system of the producers.

  15. Ion-induced nucleation of pure biogenic particles

    CERN Document Server

    Kirkby, Jasper; Sengupta, Kamalika; Frege, Carla; Gordon, Hamish; Williamson, Christina; Heinritzi, Martin; Simon, Mario; Yan, Chao; Almeida, João; Tröstl, Jasmin; Nieminen, Tuomo; Ortega, Ismael K; Wagner, Robert; Adamov, Alexey; Amorim, Antonio; Bernhammer, Anne-Kathrin; Bianchi, Federico; Breitenlechner, Martin; Brilke, Sophia; Chen, Xuemeng; Craven, Jill; Dias, antonio; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Fuchs, Claudia; Guida, Roberto; Hakala, Jani; Hoyle, Christopher R; Jokinen, Tuija; Junninen, Heikki; Kangasluoma, Juha; Kim, Jaeseok; Krapf, Manuel; Kürten, andreas; Laaksonen, Ari; Lehtipalo, Katrianne; Makhmutov, Vladimir; Mathot, Serge; Molteni, Ugo; Onnela, antti; Peräkylä, Otso; Piel, Felix; Petäjä, Tuukka; Praplan, Arnaud P; Pringle, Kirsty; Rap, Alexandru; Richards, Nigel A D; Riipinen, Ilona; Rissanen, Matti P; Rondo, Linda; Sarnela, Nina; Schobesberger, Siegfried; Scott, Catherine E; Seinfeld, John H; Sipilä, Mikko; Steiner, Gerhard; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Virtanen, Annele; Vogel, Alexander L; Wagner, Andrea C; Wagner, Paul E; Weingartner, Ernest; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Zhang, Xuan; Hansel, Armin; Dommen, Josef; Donahue, Neil M; Worsnop, Douglas R; Baltensperger, Urs; Kulmala, Markku; Carslaw, Kenneth S; Curtius, Joachim

    2016-01-01

    Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood. Globally, around half of cloud condensation nuclei originate from nucleation of atmospheric vapours. It is thought that sulfuric acid is essential to initiate most particle formation in the atmosphere and that ions have a relatively minor role. Some laboratory studies, however, have reported organic particle formation without the intentional addition of sulfuric acid, although contamination could not be excluded. Here we present evidence for the formation of aerosol particles from highly oxidized biogenic vapours in the absence of sulfuric acid in a large chamber under atmospheric conditions. The highly oxygenated molecules (HOMs) are produced by ozonolysis of $\\alpha$-pinene. We find that ions from Galactic cosmic rays increase the nucleation rate by one to two orders of magnitude compared with neutral nucleation. Our experimental findings are supported...

  16. Inter-laboratory comparison of oxygen isotope compositions from biogenic silica

    Science.gov (United States)

    Chapligin, Bernhard; Leng, Melanie J.; Webb, Elizabeth; Alexandre, Anne; Dodd, Justin P.; Ijiri, Akira; Lücke, Andreas; Shemesh, Aldo; Abelmann, Andrea; Herzschuh, Ulrike; Longstaffe, Fred J.; Meyer, Hanno; Moschen, Robert; Okazaki, Yusuke; Rees, Nicholas H.; Sharp, Zachary D.; Sloane, Hilary J.; Sonzogni, Corinne; Swann, George E. A.; Sylvestre, Florence; Tyler, Jonathan J.; Yam, Ruth

    2011-11-01

    Several techniques have been introduced in the last decades for the dehydration and release of O 2 from biogenic silica (opal-A) for oxygen-isotope analysis. However, only one silica standard is universally available: a quartz standard (NBS28) distributed by the IAEA, Vienna. Hence, there is a need for biogenic silica working standards. This paper compares the existing methods of oxygen-isotope analyses of opal-A and aims to characterize additional possible working standards to calibrate the δ18O values of biogenic silica. For this purpose, an inter-laboratory comparison was organized. Six potential working standard materials were analysed repeatedly against NBS28 by eight participating laboratories using their specific analytical methods. The materials cover a wide range of δ18O values (+23 to +43‰) and include diatoms (marine, lacustrine), phytoliths and synthetically-produced hydrous silica. To characterize the proposed standards, chemical analyses and imaging by scanning electron microscopy (SEM) were also performed. Despite procedural differences at each laboratory, all methods are in reasonable agreement with a standard deviation (SD) for δ18O values between 0.3‰ and 0.9‰ (1σ). Based on the results, we propose four additional biogenic silica working standards (PS1772-8: 42.8‰; BFC: 29.0‰; MSG60: 37.0‰; G95-25-CL leaves: 36.6‰) for δ18O analyses, available on request through the relevant laboratories.

  17. Inhibitory Effects of Spices on Biogenic Amine Accumulation during Fish Sauce Fermentation.

    Science.gov (United States)

    Zhou, Xuxia; Qiu, Mengting; Zhao, Dandan; Lu, Fei; Ding, Yuting

    2016-04-01

    The presence of high levels of biogenic amines is detrimental to the quality and safety of fish sauce. This study investigated the effects of ethanol extracts of spices, including garlic, ginger, cinnamon, and star anise extracts, in reducing the accumulation of biogenic amines during fish sauce fermentation. The concentrations of biogenic amines, which include histamine, putrescine, tyramine, and spermidine, all increased during fish sauce fermentation. When compared with the samples without spices, the garlic and star anise extracts significantly reduced these increases. The greatest inhibitory effect was observed for the garlic ethanolic extracts. When compared with controls, the histamine, putrescine, tyramine, and spermidine contents and the overall biogenic amine levels of the garlic extract-treated samples were reduced by 30.49%, 17.65%, 26.03%, 37.20%, and 27.17%, respectively. The garlic, cinnamon, and star anise extracts showed significant inhibitory effects on aerobic bacteria counts. Furthermore, the garlic and star anise extracts showed antimicrobial activity against amine producers. These findings may be helpful for enhancing the safety of fish sauce.

  18. Electrocoagulation of colloidal biogenic selenium.

    Science.gov (United States)

    Staicu, Lucian C; van Hullebusch, Eric D; Lens, Piet N L; Pilon-Smits, Elizabeth A H; Oturan, Mehmet A

    2015-02-01

    Colloidal elemental selenium (Se(0)) adversely affects membrane separation processes and aquatic ecosystems. As a solution to this problem, we investigated for the first time the removal potential of Se(0) by electrocoagulation process. Colloidal Se(0) was produced by a strain of Pseudomonas fluorescens and showed limited gravitational settling. Therefore, iron (Fe) and aluminum (Al) sacrificial electrodes were used in a batch reactor under galvanostatic conditions. The best Se(0) turbidity removal (97 %) was achieved using iron electrodes at 200 mA. Aluminum electrodes removed 96 % of colloidal Se(0) only at a higher current intensity (300 mA). At the best Se(0) removal efficiency, electrocoagulation using Fe electrode removed 93 % of the Se concentration, whereas with Al electrodes the Se removal efficiency reached only 54 %. Due to the less compact nature of the Al flocs, the Se-Al sediment was three times more voluminous than the Se-Fe sediment. The toxicity characteristic leaching procedure (TCLP) test showed that the Fe-Se sediment released Se below the regulatory level (1 mg L(-1)), whereas the Se concentration leached from the Al-Se sediment exceeded the limit by about 20 times. This might be related to the mineralogical nature of the sediments. Electron scanning micrographs showed Fe-Se sediments with a reticular structure, whereas the Al-Se sediments lacked an organized structure. Overall, the results obtained showed that the use of Fe electrodes as soluble anode in electrocoagulation constitutes a better option than Al electrodes for the electrochemical sedimentation of colloidal Se(0).

  19. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    2002-08-10

    Radionuclide and heavy metal contaminants at DOE sites pose immediate and long-term environmental problems. Under the NABIR program, bacteria are being considered for their role in the cycling of these contaminants because they influence many redox reactions in the subsurface. Dissimilatory metal reducing bacteria (DMRB) are particularly important to controlling the biogeochemistry of subsurface environments through enzymatic reduction of iron and manganese minerals. During reduction of FeIII, biogenic FeII phases form at the cell-mineral interface which may profoundly influence metal reduction.

  20. Developmental expression analysis and immunolocalization of a biogenic amine receptor in Schistosoma mansoni

    OpenAIRE

    El-Shehabi, Fouad; Vermeire, Jon J.; Yoshino, Timothy P.; Ribeiro, Paula

    2009-01-01

    A Schistosoma mansoni G-protein coupled receptor (SmGPCR) was previously cloned and shown to be activated by the biogenic amine, histamine. Here we report a first investigation of the receptor’s subunit organization, tissue distribution and expression levels in different stages of the parasite. A polyclonal antibody was produced in rabbits against the recombinant third intracellular loop (il3) of SmGPCR. Western blot studies of the native receptor and recombinant protein expressed in HEK293 c...

  1. Bioassay for estimating the biogenic methane-generating potential of coal samples

    Science.gov (United States)

    Jones, E.J.P.; Voytek, M.A.; Warwick, P.D.; Corum, M.D.; Cohn, A.; Bunnell, J.E.; Clark, A.C.; Orem, W.H.

    2008-01-01

    Generation of secondary biogenic methane in coal beds is likely controlled by a combination of factors such as the bioavailability of coal carbon, the presence of a microbial community to convert coal carbon to methane, and an environment supporting microbial growth and methanogenesis. A set of treatments and controls was developed to bioassay the bioavailability of coal for conversion to methane under defined laboratory conditions. Treatments included adding a well-characterized consortium of bacteria and methanogens (enriched from modern wetland sediments) and providing conditions to support endemic microbial activity. The contribution of desorbed methane in the bioassays was determined in treatments with bromoethane sulfonic acid, an inhibitor of microbial methanogenesis. The bioassay compared 16 subbituminous coal samples collected from beds in Texas (TX), Wyoming (WY), and Alaska (AK), and two bituminous coal samples from Pennsylvania (PA). New biogenic methane was observed in several samples of subbituminous coal with the microbial consortium added, but endemic activity was less commonly observed. The highest methane generation [80????mol methane/g coal (56??scf/ton or 1.75??cm3/g)] was from a south TX coal sample that was collected from a non-gas-producing well. Subbituminous coals from the Powder River Basin, WY and North Slope Borough, AK contained more sorbed (original) methane than the TX coal sample and generated 0-23????mol/g (up to 16??scf/ton or 0.5??cm3/g) new biogenic methane in the bioassay. Standard indicators of thermal maturity such as burial depth, nitrogen content, and calorific value did not explain differences in biogenic methane among subbituminous coal samples. No original methane was observed in two bituminous samples from PA, nor was any new methane generated in bioassays of these samples. The bioassay offers a new tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the

  2. Differences between biogenic amine detection by HPLC methods using OPA and dansyl derivates.

    Science.gov (United States)

    Alberto, María R; Arena, Mario E; De Nadra, María C Manca

    2004-01-01

    Biogenic amines can be formed and degraded as a result of normal metabolic activity in animals, plants, and microorganisms and are usually produced by the decarboxylation of amino acids. Recent trends in food security are promoting an increasing search for trace compounds that can affect human health. Although they are present in fermented foods and beverages in low quantities, they exhibit interactions with normal human metabolism (e.g., having vasoactive or psychoactive properties) that justify the research on their presence in foods and the possible related toxicological effects that they may cause. Estimation of the biogenic amines histamine, tyramine, agmatine, putrescine, and cadaverine is important not only from the point of view of their toxicity, but also because they can be used as indicators of the degree of freshness or spoilage of food. Until recently, because of the difficulty in detecting and quantifying amines reliably we have had insufficient information about their occurrence in different types of foods and beverages. These problems are related to matrix interference (e.g., the presence of free amino acids) and the low levels at which the amines are found. Early techniques for the determination of biogenic amines in foods were based on thin-layer chromatography. More modern analytical techniques have since been developed that allow the acquisition of reliable quantitative data and better separation/resolution of various amines. The quantitative determination of biogenic amines is generally accomplished by overpressure-layer chromatography, high-performance liquid chromatography (HPLC), and gas chromatography. The use of reverse-phase column and precolumn derivatization was more efficient and faster than the conventional ion-exchange techniques. This study was conducted to evaluate two HPLC derivatization methods for quantitative determination of biogenic amines: the method described by Gonzales de Llano et al. for amino acid analysis and the

  3. Modeling biogenic gas bubbles formation and migration in coarse sand

    Science.gov (United States)

    Ye, S.

    2011-12-01

    Shujun Ye Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China; sjye@nju.edu.cn Brent E. Sleep Department of Civil Engineering, University of Toronto, Toronto, ON, M5S 1A4 CANADA; sleep@ecf.utoronto.ca Methane gas generation in porous media was investigated in an anaerobic two-dimensional sand-filled cell. Inoculation of the lower portion of the cell with a methanogenic culture and addition of methanol to the bottom of the cell led to biomass growth and formation of a gas phase. The formation, migration, distribution and saturation of gases in the cell were visualized by the charge-coupled device (CCD) camera. Gas generated at the bottom of the cell in the biologically active zone moved upwards in discrete fingers, so that gas phase saturations (gas-filled fraction of void space) in the biologically active zone at the bottom of the cell did not exceed 40-50%, while gas accumulation at the top of the cell produced gas phase saturations as high as 80%. Macroscopic invasion percolation (MIP) at near pore scale[Glass, et al., 2001; Kueper and McWhorter, 1992]was used to model gas bubbles growth in porous media. The nonwetting phase migration pathway can be yielded directly by MIP. MIP was adopted to simulate the expansion, fragmentation, and mobilization of gas clusters in the cell. The production of gas, and gas phash saturations were simulated by a continuum model - compositional simulator (COMPSIM) [Sleep and Sykes, 1993]. So a combination of a continuum model and a MIP model was used to simulate the formation, fragmentation and migration of biogenic gas bubbles. Key words: biogenic gas; two dimensional; porous media; MIP; COMPSIM

  4. Biogenic aerosol over the Amazon Basin

    Science.gov (United States)

    Guyon, P.; Mayol-Bracero, O. L.; Matthias-Maser, S.; Godoi, R. H.; van Grieken, R.; Ebert, M.; Huth, J.; Maenhaut, W.; Taylor, P.; Artaxo, P.; Andreae, M. O.

    2002-12-01

    Biogenic particles form the major component of the atmospheric aerosol above and within the vast Amazonian tropical rainforest under non-polluted "background" conditions. We have employed a variety of different analytical techniques in order to try to better characterise the composition and temporal variation of this aerosol fraction. Microscopic examination reveals that many different types of biological particles are present, including fungal and fern spores, pollen grains, microbes, plant debris and insect parts. These forest-derived particles, and the elements, ions and compounds associated with them, are abundant in both the coarse and fine aerosol fractions, with the highest mass concentrations generally in the coarse fraction. There is a distinct increase in their concentrations at ground level at night. This is probably due to the formation of a shallow nocturnal inversion, which reduces dispersion of the aerosol, whilst convective mixing during the day leads to efficient dilution with air from aloft. Preferential nighttime emission of some types of biogenic particles may also contribute to the observed day-night variation.

  5. Methyl chavicol: characterization of its biogenic emission rate

    NARCIS (Netherlands)

    Bouvier-Brown, N.C.; Goldstein, A.H.; Worton, D.R.; Matross, D.M.; Gilman, J.B.; Kuster, W.C.; Welsh-Bon, D.; Warneke, C.; de Gouw, J.A.; Cahill, M.J.; Holzinger, R.

    2009-01-01

    We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Meth

  6. Factors influencing biogenic amines accumulation in dairy products

    Directory of Open Access Journals (Sweden)

    Daniel M. eLinares

    2012-05-01

    Full Text Available Fermented foods are within the food products more often complained of having caused biogenic amines poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain significant levels of biogenic amines, specially tyramine, histamine and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report about cheese elaboration and processing technological aspects affecting biogenic amines levels. Synthesis of biogenic amines is possible only when three conditions converge: i availability of the substrate amino acids; ii presence of microorganisms with the appropriate catabolic pathway activated; and iii environmental conditions favorable to the decarboxilation activity. These conditions depend on several factors such as milk treatment (pasteurization, use of starter cultures, NaCl concentration, time and temperature of ripening and preservation, pH… which will be discussed in this chapter.

  7. Biogenic gas in the Cambrian-Ordovcian Alum Shale (Denmark and Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H.M.; Wirth, R.; Biermann, S.; Arning, E.T. [Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ, Potsdam (Germany); Krueger, M.; Straaten, N. [BGR Hannover (Germany); Bechtel, A. [Montanuniv. Leoben (Austria); Berk, W. van [Technical Univ. of Clausthal (Germany); Schovsbo, N.H. [Geological Survey of Denmark and Greenland - GEUS, Copenhagen (Denmark); Crabtree, Stephen [Gripen Gas (Sweden)

    2013-08-01

    Shale gas is mainly produced from thermally mature black shales. However, biogenic methane also represents a resource which is often underestimated. Today biogenic methane is being produced from the Upper Devonian Antrim Shale in the Michigan Basin which was the most successfully exploited shale gas system during the 1990-2000 decade in the U.S.A. before significant gas production from the Barnett Shale started (Curtis et al., 2008). The Cambro-Ordovician Alum Shale in northern Europe has thermal maturities ranging from overmature in southern areas (Denmark and southern Sweden) to immature conditions (central Sweden). Biogenic methane is recorded during drilling in central Sweden. The immature Alum Shale in central Sweden has total organic carbon (TOC) contents up to 20 wt%. The hydrogen index HI ranges from 380 to 560 mgHC/gTOC at very low oxygen index (OI) values of around 4 mg CO{sub 2}/gTOC, Tmax ranges between 420 - 430 C. The organic matter is highly porous. In general, the Alum Shale is a dense shale with intercalated sandy beds which may be dense due to carbonate cementation. Secondary porosity is created in some sandy beds due to feldspar dissolution and these beds serve as gas conduits. Methane production rates with shale as substrate in the laboratory are dependent on the kind of hydrocarbon-degrading microbial enrichment cultures used in the incubation experiments, ranging from 10-620 nmol/(g*d). In these experiments, the CO{sub 2} production rate was always higher than for methane. Like the northern part of North America, also Northern European has been covered by glaciers during the Pleistocene and similar geological processes may have developed leading to biogenic shale gas formation. For the Antrim Shale one hypothesis suggests that fresh waters, recharged from Pleistocene glaciation and modern precipitation, suppressed basinal brine salinity along the northern margins of the Michigan Basin to greater depths and thereby enhancing methanogenesis

  8. Model for The Diffusionof Biogenic Gases In Heterogeneous Reservoirs Undergoing Transient Flow

    Directory of Open Access Journals (Sweden)

    Nmegbu, Chukwuma Godwin Jacob

    2014-06-01

    Full Text Available Microbially enhanced petroleum reservoirs confirms a recovery of about 30-40 % residual oil, with an integral composition of wide range of oil recovery mechanisms including wettability alteration by biosurfactant production, selective plugging of highly permeable channels by biopolymer production, creating fluid flow channels in carbonate reservoirs by rock dissolution attributed to bioacid formation, and a range of other exploitable recovery techniques. This study presents an investigation of biogenic gas produced in-situ and its concentration profile across the reservoir. An increasing concentration trend in the grids was observed and these increments were owed to the fact that diffusion of the biogenic occurred. It was also observed that after 40days of Desulfovibro injection, the produced CO2 across the reservoir was tending towards being even in values of concentration, implying that diffusion rate was approaching a zero value. Also, the distorting effect of reservoir heterogeneity on biogenic gas concentration profile was also resolved by adopting the method of averaging for permeability and porosity in the reservoir.

  9. Biogenic amines at a low level of evolution: Production, functions and regulation in the unicellular Tetrahymena.

    Science.gov (United States)

    Csaba, György

    2015-06-01

    The unicellular eukaryote Tetrahymena synthesize, store and secrete biogenic amines (histamine, serotonin, epinephrine, dopamine, melatonin) and also can take up amines from the milieu. It also has (G-protein-coupled) receptors (binding sites) for these amines as well, as second messengers. The factors infuencing the mentioned processes are shown. For certain amines the genes and the coded enzymes are demonstrated. The amines influence phagocytosis, cell division, ciliary regeneration, glucose metabolism and chemotaxis. There are interhormone actions between the amines, and between the amines and other hormones produced by Tetrahymena. The critical review discusses the role of amines in the early stages of evolution and compares this to their functions in mammals. It tries to give answer how and why biogenic amines were selected to hormones, and why new functions formed for them in higher ranked animals, preserving also the ancient ones.

  10. Total balance of biogenic fuels for thermal uses; Ganzheitliche Bilanzierung verschiedener biogener Festbrennstoffe zur thermischen Nutzung

    Energy Technology Data Exchange (ETDEWEB)

    Becher, S.; Kaltschmitt, M. [Stuttgart Univ. (Germany). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER)

    1996-12-31

    In this situation of unfavourable energy price levels, the use of biogenic fuels for power supply can be recommended only if it serves to reduce environmental pollution. Against this background and on the basis of a primary energy balance, the authors attempted a total balance of selected enfironmental effects (global heating and acidification potential) of biomass use as compared to fossil fuel combustion. (orig) [Deutsch] ie Nutzung biogener Festbrennstoffe zur Energienachfragedeckung ist bei dem gegenwaertigen unguenstigen Energiepreisniveau nur dann zu rechtfertigen, wenn es durch die Biomassenutzung zu einer Reduzierung der energiebedingten Umwelteffekte kommt. Vor disem Hintergrund werden ausgehend von der Primaerenergiebilanz ausgewaehlte Umwelteffekte (d.h. das Treibhaus- und das Versauerungspotential) einer Biomassenutzung im Vergleich zu einer Nutzung fossiler Energietraeger ganzheitlich bilanziert. Die wesentlichen Ergebnisse werden zusammengefasst und interpretiert. (orig)

  11. Biogenic catalysis of soil formation on Mars?

    Science.gov (United States)

    Bishop, J. L.

    1998-01-01

    The high iron abundance and the weak ferric iron spectral features of martian surface material are consistent with nanophase (nm-sized) iron oxide minerals as a major source of iron in the bright region soil on Mars. Nanophase iron oxide minerals, such as ferrihydrite and schwertmannite, and nanophase forms of hematite and goethite are formed by both biotic and abiotic processes on Earth. The presence of these minerals on Mars does not indicate biological activity on Mars, but it does raise the possibility. This work includes speculation regarding the possibility of biogenic soils on Mars based on previous observations and analyses. A remote sensing goal of upcoming missions should be to determine if nanophase iron oxide minerals, clay silicates and carbonates are present in the martian surface material. These minerals are important indicators for exobiology and their presence on Mars would invoke a need for further investigation and sample return from these sites.

  12. BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

    Directory of Open Access Journals (Sweden)

    Radka Flasarová

    2012-02-01

    Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

  13. Biogenic amines in meat and fermented meat products

    Directory of Open Access Journals (Sweden)

    Joanna Stadnik

    2010-09-01

    Full Text Available Recent trends in food quality and safety promote an increasing search for trace compounds that can affect human health. Biogenic amines belong to this group of substances. They can cause distinctive pharmacological, physiological and toxic effects in organisms. Their amounts are usually increasing as a consequence of the use of poor quality raw materials, during controlled or spontaneous microbial fermentation or in the course of food spoilage. The origin of biogenic amines makes them suitable as chemical indicators of the hygienic quality and freshness of some foods being associated to the degree of food fermentation or degradation. The development of appropriate manufacturing technologies to obtain products free or nearly free from biogenic amines is a challenge for the meat industry. This review briefly summarises current knowledge on the biological implications of biogenic amines on human health and collects data on the factors affecting their formation in meat and fermented meat products.

  14. Origin of organism-dependent biogenic silica quartz formation.

    Science.gov (United States)

    Sato, Kiminori

    2011-12-15

    Organism-dependent biogenic quartz formation in the steady-state environment is a phenomenon that can address the global environmental issues such as diagenetic evolution, biogeochemical cycling, and reservoir formation, but detailed studies have not been performed so far. Here, steady-state quartz formation is studied for amorphous silica of different biogenic origin on the basis of the recently established mechanistic model [Sato et al., J. Phys. Chem. C 2011, 115, 18131]. Amorphous silica originated from rice husks possesses angstrom-scale pores larger by 1.3 Å than those originated from diatom algae. The slight difference of pore size dramatically reduces activation energies of water diffusion by 78% and reactions of water molecules at pore surfaces by 47%, resulting in the reduction of activation energy of biogenic quartz formation by 64%. The present findings evidence that angstrom-scale pores intrinsically residing in the amorphous matrix are the organism-dependent origin of steady-state biogenic quartz formation.

  15. Modelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarctica

    Directory of Open Access Journals (Sweden)

    M. Vichi

    2009-07-01

    Full Text Available Several biogeochemical data have been collected in the last 10 years of Italian activity in Antarctica (ABIOCLEAR, ROSSMIZE, BIOSESO-I/II. A comprehensive 1-D biogeochemical model was implemented as a tool to link observations with processes and to investigate the mechanisms that regulate the flux of biogenic material through the water column. The model is ideally located at station B (175° E–74° S and was set up to reproduce the seasonal cycle of phytoplankton and organic matter fluxes as forced by the dominant water column physics over the period 1990–2001. Austral spring-summer bloom conditions are assessed by comparing simulated nutrient drawdown, primary production rates, bacterial respiration and biomass with the available observations. The simulated biogenic fluxes of carbon, nitrogen and silica have been compared with the fluxes derived from sediment traps data. The model reproduces the observed magnitude of the biogenic fluxes, especially those found in the bottom sediment trap, but the peaks are markedly delayed in time. Sensitivity experiments have shown that the characterization of detritus, the choice of the sinking velocity and the degradation rates are crucial for the timing and magnitude of the vertical fluxes. An increase of velocity leads to a shift towards observation but also to an overestimation of the deposition flux which can be counteracted by higher bacterial remineralization rates. Model results suggest that the timing of the observed fluxes depends first and foremost on the timing of surface production and on a combination of size-distribution and quality of the autochtonous biogenic material. It is hypothesized that the bottom sediment trap collects material originated from the rapid sinking of freshly-produced particles and also from the previous year's production period.

  16. Absorption of Visible and Long-wave Radiation by Primary and Secondary Biogenic Aerosols.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.

    2008-12-01

    Field results for the 14C content of carbonaceous aerosols are presented that indicate significant biogenic sources of both primary and secondary aerosols in urban and regional environments. Samples collected in Mexico City and downwind of the urban area during the MILAGRO field study are compared with results reported previously in the literature indicating a significant amount of biogenic aerosols from both biomass burning and secondary photochemical production (e.g. terpene oxidations) are contributing to the overall carbonaceous aerosols in the optically active region of 0.1 to 1.0 micron. Samples in this size range collected on quartz fiber filters were also examined using an integrating sphere and FTIR diffuse reflectance techniques to obtain absorption spectra from 280 to the mid-IR. These data clearly indicate that the biogenic derived primary aerosols from agricultural and trash-burning, as well as secondary organic aerosols from isoprene and terpene oxidations will produce both UV-Visible (short-wave) absorbing substances as well as IR (long-wave) absorbing compounds including humic-like-substances (HULIS). With the anticipated increases in growing seasons (i.e. earlier springs and longer summers) the likely hood of increased fires (forest and grassland) as well as the continuing growth in agricultural burning activities, these primary sources are expected to increase and may play a role in heating of the atmosphere. The compound effects of these primary and secondary biogenic sources of absorbing aerosols to the total aerosol loading and regional climate will be discussed. This work was supported by the Office of Science (BER), U.S. Department of Energy, Grant No. DE-FG02-07ER64328 as part of the Atmospheric Science Program.

  17. Organosulfate formation in biogenic secondary organic aerosol.

    Science.gov (United States)

    Surratt, Jason D; Gómez-González, Yadian; Chan, Arthur W H; Vermeylen, Reinhilde; Shahgholi, Mona; Kleindienst, Tadeusz E; Edney, Edward O; Offenberg, John H; Lewandowski, Michael; Jaoui, Mohammed; Maenhaut, Willy; Claeys, Magda; Flagan, Richard C; Seinfeld, John H

    2008-09-11

    Organosulfates of isoprene, alpha-pinene, and beta-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive series of laboratory photooxidation (i.e., OH-initiated oxidation) and nighttime oxidation (i.e., NO3-initiated oxidation under dark conditions) experiments using nine monoterpenes (alpha-pinene, beta-pinene, d-limonene, l-limonene, alpha-terpinene, gamma-terpinene, terpinolene, Delta(3)-carene, and beta-phellandrene) and three monoterpenes (alpha-pinene, d-limonene, and l-limonene), respectively. Organosulfates were characterized using liquid chromatographic techniques coupled to electrospray ionization combined with both linear ion trap and high-resolution time-of-flight mass spectrometry. Organosulfates are formed only when monoterpenes are oxidized in the presence of acidified sulfate seed aerosol, a result consistent with prior work. Archived laboratory-generated isoprene SOA and ambient filter samples collected from the southeastern U.S. were reexamined for organosulfates. By comparing the tandem mass spectrometric and accurate mass measurements collected for both the laboratory-generated and ambient aerosol, previously uncharacterized ambient organic aerosol components are found to be organosulfates of isoprene, alpha-pinene, beta-pinene, and limonene-like monoterpenes (e.g., myrcene), demonstrating the ubiquity of organosulfate formation in ambient SOA. Several of the organosulfates of isoprene and of the monoterpenes characterized in this study are ambient tracer compounds for the occurrence of biogenic SOA formation under acidic conditions. Furthermore, the nighttime oxidation experiments conducted under highly acidic conditions reveal a viable mechanism for the formation of previously identified nitrooxy organosulfates found in ambient nighttime aerosol samples. We estimate

  18. Sub-Antarctic marine aerosol: significant contributions from biogenic sources

    Directory of Open Access Journals (Sweden)

    J. Schmale

    2013-03-01

    Full Text Available Biogenic influences on the composition and characteristics of aerosol were investigated on Bird Island (54°00' S, 38°03' W in the South Atlantic during November and December 2010. This remote marine environment is characterised by large seabird and seal colonies. The chemical composition of the submicron particles, measured by an aerosol mass spectrometer (AMS, was 21% non-sea salt sulfate 2% nitrate, 7% ammonium, 22% organics and 47% sea salt including sea salt sulfate. A new method to isolate the sea salt signature from the high-resolution AMS data was applied. Generally, the aerosol was found to be less acidic than in other marine environments due to the high availability of ammonia, from local fauna emissions. By positive matrix factorisation five different organic aerosol (OA profiles could be isolated: an amino acids/amine factor (AA-OA, 18% of OA mass, a methanesulfonic acid OA factor (MSA-OA, 25%, a marine oxygenated OA factor (M-OOA, 40%, a sea salt OA fraction (SS-OA, 7% and locally produced hydrocarbon-like OA (HOA, 9%. The AA-OA was dominant during the first two weeks of November and found to be related with the hatching of penguins in a nearby colony. This factor, rich in nitrogen (C : N ratio = 0.13, has implications for the biogeochemical cycling of nitrogen in the area as particulate matter is often transported over longer distances than gaseous N-rich compounds. The MSA-OA was mainly transported from more southerly latitudes where phytoplankton bloomed. The bloom was identified as one of three sources for particulate sulfate on Bird Island, next to sea salt sulfate and sulfate transported from South America. M-OOA was the dominant organic factor and found to be similar to marine OA observed at Mace Head, Ireland. An additional OA factor highly correlated with sea salt aerosol was identified (SS-OA. However, based on the available data the type of mixture, internal or external, could not be determined. Potassium was not

  19. Sub-Antarctic marine aerosol: dominant contributions from biogenic sources

    Directory of Open Access Journals (Sweden)

    J. Schmale

    2013-09-01

    Full Text Available Biogenic influences on the composition and characteristics of aerosol were investigated on Bird Island (54°00' S, 38°03' W in the South Atlantic during November and December 2010. This remote marine environment is characterised by large seabird and seal colonies. The chemical composition of the submicron particles, measured by an aerosol mass spectrometer (AMS, was 21% non-sea-salt sulfate, 2% nitrate, 8% ammonium, 22% organics and 47% sea salt including sea salt sulfate. A new method to isolate the sea spray signature from the high-resolution AMS data was applied. Generally, the aerosol was found to be less acidic than in other marine environments due to the high availability of ammonia, from local fauna emissions. By positive matrix factorisation five different organic aerosol (OA profiles could be isolated: an amino acid/amine factor (AA-OA, 18% of OA mass, a methanesulfonic acid OA factor (MSA-OA, 25%, a marine oxygenated OA factor (M-OOA, 41%, a sea spray OA fraction (SS-OA, 7% and locally produced hydrocarbon-like OA (HOA, 9%. The AA-OA was dominant during the first two weeks of November and found to be related with the hatching of penguins in a nearby colony. This factor, rich in nitrogen (N : C ratio = 0.13, has implications for the biogeochemical cycling of nitrogen in the area as particulate matter is often transported over longer distances than gaseous N-rich compounds. The MSA-OA was mainly transported from more southerly latitudes where phytoplankton bloomed. The bloom was identified as one of three sources for particulate sulfate on Bird Island, next to sea salt sulfate and sulfate transported from South America. M-OOA was the dominant organic factor and found to be similar to marine OA observed at Mace Head, Ireland. An additional OA factor highly correlated with sea spray aerosol was identified (SS-OA. However, based on the available data the type of mixture, internal or external, could not be determined. Potassium was not

  20. On Mineral Retrosynthesis of a Complex Biogenic Scaffold

    OpenAIRE

    Ashit Rao; José L Arias; Helmut Cölfen

    2017-01-01

    Synergistic relations between organic molecules and mineral precursors regulate biogenic mineralization. Given the remarkable material properties of the egg shell as a biogenic ceramic, it serves as an important model to elucidate biomineral growth. With established roles of complex anionic biopolymers and a heterogeneous organic scaffold in egg shell mineralization, the present study explores the regulation over mineralization attained by applying synthetic polymeric counterparts (polyethyle...

  1. Geochemical characteristics and origin of light hydrocarbons in biogenic gas

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The light hydrocarbon geochemical characteristics of biogenic gases from Sebei 1 gas field in the Qaidam Basin, Baoshan gas field in the Baoshan Basin and Alaxin gas field, Puqian gas pool, Aonan gas pool in the Songliao Basin are studied and the origin is discussed based on the composition and isotope data of gases. The isoalkane contents among light hydrocarbons in natural gas show a negative relationship with δ13C1 values. The isoalkane contents of the gases with δ13C1 values of less than ?60‰ are also high with more than 40% among light hydrocarbons in Sebei 1 gas field and Puqian gas pool. Moreover, the 2,2-dimethylbutane and 2-methylpentane, mainly sourced from bacteria, have predominance among isoalkanes, which suggests that light hydrocarbons in biogenic gases from these gas fields or pools were probably generated by microbial action. However, the cycloalkane contents among light hydrocarbons in biogenic gas are related to δ13C1 values positively. In Alaxin gas field and Aonan gas pool, where δ13C1 values of biogenic gases are less than ?60‰, the average contents of cycloalkane are higher than 44%. Light hydrocarbons among biogenic gases from these gas fields were probably generated by catalysis. The isoalkane and cycloalkane contents among light hydrocarbons from biogenic gases in the Baoshan gas field are both high, which might be generated by these two actions. The results show that the data of light hydrocarbons in biogenic gas can provide important information for understanding the generation mechanisms of light hydrocarbons during geological evolution and identifying biogenic gas and low mature gas.

  2. Biogenic aldehyde determination by reactive paper spray ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bag, Soumabha; Hendricks, P.I. [Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907 (United States); Reynolds, J.C. [Centre for Analytical Science, Loughborough University, Loughborough, Leicestershire (United Kingdom); Cooks, R.G., E-mail: cooks@purdue.edu [Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907 (United States)

    2015-02-20

    Highlights: • In-situ derivatization and simultaneous ionization used to detect aldehydes. • Biogenic aliphatic and aromatic aldehydes reacted with 4-aminophenol. • Derivatized products yield structurally characteristic fragment ions. • This measurement demonstrated using a miniaturized portable mass spectrometer. - Abstract: Ionization of aliphatic and aromatic aldehydes is improved by performing simultaneous chemical derivatization using 4-aminophenol to produce charged iminium ions during paper spray ionization. Accelerated reactions occur in the microdroplets generated during the paper spray ionization event for the tested aldehydes (formaldehyde, n-pentanaldehyde, n-nonanaldehyde, n-decanaldehyde, n-dodecanaldehyde, benzaldehyde, m-anisaldehyde, and p-hydroxybenzaldehyde). Tandem mass spectrometric analysis of the iminium ions using collision-induced dissociation demonstrated that straight chain aldehydes give a characteristic fragment at m/z 122 (shown to correspond to protonated 4-(methyleneamino)phenol), while the aromatic aldehyde iminium ions fragment to give a characteristic product ion at m/z 120. These features allow straightforward identification of linear and aromatic aldehydes. Quantitative analysis of n-nonaldehyde using a benchtop mass spectrometer demonstrated a linear response over 3 orders of magnitude from 2.5 ng to 5 μg of aldehyde loaded on the filter paper emitter. The limit of detection was determined to be 2.2 ng for this aldehyde. The method had a precision of 22%, relative standard deviation. The experiment was also implemented using a portable ion trap mass spectrometer.

  3. Biogenic amines and hygienic quality of lucerne silage

    Directory of Open Access Journals (Sweden)

    Mlejnkova Veronika

    2016-01-01

    Full Text Available This experiment examined the influence of two different silage additives of biological (Lactococcus lactis, Lactobacillus plantarum, Enterococcus faecium, enzyme xylanase and chemical (43% formic acid, 30% ammonium formate, 10% propionic acid, 2% benzoic acid types on biogenic amines concentration, nutrient content, fermentation process, and microbiologic indicators in lucerne (Medicago sativa silage after 90 days of fermentation. The biological additive significantly (P < 0.05 increased putrescine (+51%, lactic acid (+11% and protein content (+11% in comparison with control silage. It significantly decreased cadaverine (−29%, histamine (−57%, spermidine (−15%, spermine (−55%, acetic acid (−40%, ethanol (−55%, ammonium (−25% and ash (−9%. After the chemical-additive treatment, greater amounts of histamine and tyramine were recorded. Significant decrease was observed in the concentrations of putrescine (−18%, cadaverine (−55%, spermidine (−47%, spermine (−45%, lactic acid (−16%, acetic acid (−46%, ammonium (−59%, ash (−13% and fat (−24%. Populations of bacteria associated with lactic acid fermentation, moulds, yeasts, enterobacteria and total microorganisms count were also influenced. Both biological and chemical additives can be highly recommended for producing high-quality silages meeting hygienic requirements. In lucerne silage, the chemical preservative showed a stronger effect in achieving the health safety of silage compared to the biological inoculant.

  4. Technological Factors Affecting Biogenic Amine Content in Foods: A Review

    Science.gov (United States)

    Gardini, Fausto; Özogul, Yesim; Suzzi, Giovanna; Tabanelli, Giulia; Özogul, Fatih

    2016-01-01

    Biogenic amines (BAs) are molecules, which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine, and agmatine. The importance of preventing the excessive accumulation of BAs in foods is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BAs accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting BA content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity, and other BAs), environmental factors influencing BA formation (temperature, salt concentration, and pH). In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolizing BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances) are addressed. PMID:27570519

  5. Biogenic amines in wines from three Spanish regions.

    Science.gov (United States)

    Landete, José M; Ferrer, Sergi; Polo, Lucía; Pardo, Isabel

    2005-02-23

    One hundred and sixty-three wines from La Rioja, Utiel-Requena, and Tarragona were analyzed to determine if there were any differences in the concentrations of six biogenic amines that are found in these three regions. The influence of grape variety, type of vinification, wine pH, malolactic fermentation, and storage in bottle on biogenic amine concentrations was studied. Results show important differences in putrescine and histamine concentrations among regions, varieties of grape, and type of wine; differences were less appreciable for the remaining biogenic amines studied. Low pH prevented biogenic amine formation. Malolactic fermentation and short storage periods in bottle (3-6 months) showed increases in histamine concentration, whereas longer periods of storage led to a general decrease in histamine. Several strains of lactic acid bacteria were isolated in this work, and their ability to form biogenic amines was assayed in synthetic media, grape must, and wine. Grape varieties, different types of winemaking, pH, and lactic acid bacteria may be responsible for the differences observed in the biogenic amine concentrations of the wines analyzed.

  6. Biogenic amine production by Lactococcus lactis subsp. cremoris strains in the model system of Dutch-type cheese.

    Science.gov (United States)

    Flasarová, Radka; Pachlová, Vendula; Buňková, Leona; Menšíková, Anna; Georgová, Nikola; Dráb, Vladimír; Buňka, František

    2016-03-01

    The aim of this study was to compare the biogenic amine production of two starter strains of Lactococcus lactis subsp. cremoris (strains from the Culture Collection of Dairy Microorganisms - CCDM 824 and CCDM 946) with decarboxylase positive activity in a model system of Dutch-type cheese during a 90-day ripening period at 10°C. During ripening, biogenic amine and free amino acid content, microbiological characteristics and proximate chemical properties were observed. By the end of the ripening period, the putrescine content in both samples with the addition of the biogenic amine producing strain almost evened out and the concentration of putrescine was >800mg/kg. The amount of tyramine in the cheeses with the addition of the strain of CCDM 824 approached the limit of 400mg/kg by the end of ripening. In the cheeses with the addition of the strain of CCDM 946 it even exceeded 500mg/kg. In the control samples, the amount of biogenic amines was insignificant.

  7. Biogenic Carbon on Mars: A Subsurface Chauvinistic Viewpoint

    Science.gov (United States)

    Onstott, T. C.; Lau, C. Y. M.; Magnabosco, C.; Harris, R.; Chen, Y.; Slater, G.; Sherwood Lollar, B.; Kieft, T. L.; van Heerden, E.; Borgonie, G.; Dong, H.

    2015-12-01

    A review of 150 publications on the subsurface microbiology of the continental subsurface provides ~1,400 measurements of cellular abundances down to 4,800 meter depth. These data suggest that the continental subsurface biomass is comprised of ~1016-17 grams of carbon, which is higher than the most recent estimates of ~1015 grams of carbon (1 Gt) for the marine deep biosphere. If life developed early in Martian history and Mars sustained an active hydrological cycle during its first 500 million years, then is it possible that Mars could have developed a subsurface biomass of comparable size to that of Earth? Such a biomass would comprise a much larger fraction of the total known Martian carbon budget than does the subsurface biomass on Earth. More importantly could a remnant of this subsurface biosphere survive to the present day? To determine how sustainable subsurface life could be in isolation from the surface we have been studying subsurface fracture fluids from the Precambrian Shields in South Africa and Canada. In these environments the energetically efficient and deeply rooted acetyl-CoA pathway for carbon fixation plays a central role for chemolithoautotrophic primary producers that form the base of the biomass pyramid. These primary producers appear to be sustained indefinitely by H2 generated through serpentinization and radiolytic reactions. Carbon isotope data suggest that in some subsurface locations a much larger population of secondary consumers are sustained by the primary production of biogenic CH4 from a much smaller population of methanogens. These inverted biomass and energy pyramids sustained by the cycling of CH4 could have been and could still be active on Mars. The C and H isotopic signatures of Martian CH4 remain key tools in identifying potential signatures of an extant Martian biosphere. Based upon our results to date cavity ring-down spectroscopic technologies provide an option for making these measurements on future rover missions.

  8. Reactivity of biogenic manganese oxide for metal sequestration and photochemistry: Computational solid state physics study

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, K.D.; Sposito, G.

    2010-02-01

    Many microbes, including both bacteria and fungi, produce manganese (Mn) oxides by oxidizing soluble Mn(II) to form insoluble Mn(IV) oxide minerals, a kinetically much faster process than abiotic oxidation. These biogenic Mn oxides drive the Mn cycle, coupling it with diverse biogeochemical cycles and determining the bioavailability of environmental contaminants, mainly through strong adsorption and redox reactions. This mini review introduces recent findings based on quantum mechanical density functional theory that reveal the detailed mechanisms of toxic metal adsorption at Mn oxide surfaces and the remarkable role of Mn vacancies in the photochemistry of these minerals.

  9. Characterization of biogenic secondary organic aerosols using statistical methods; Charakterisierung Biogener Sekundaerer Organischer Aerosole mit Statistischen Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, Christian

    2010-07-01

    Atmospheric aerosols have important influence on the radiation balance of the Earth, on visibility and human health. Secondary organic aerosol is formed from gas-to-particle conversion of oxidized volatile organic compounds. A dominant fraction of the gases originates from plant emissions, making biogenic secondary organic aerosol (BSOA) an especially important constituent of the atmosphere. Knowing the chemical composition of BSOA particles is crucial for a thorough understanding of aerosol processes in the environment. In this work, the chemical composition of BSOA particles was measured with aerosol mass spectrometry and analyzed with statistical methods. The experimental part of the work comprises process studies of the formation and aging of biogenic aerosols in simulation chambers. Using a plant chamber, real tree emissions were used to produce particles in a way close to conditions in forest environments. In the outdoor chamber SAPHIR, OH-radicals were produced from the photooxidation of ozone under illumination with natural sunlight. Here, BSOA was produced from defined mixtures of mono- and sesquiterpenes that represent boreal forest emissions. A third kind of experiments was performed in the indoor chamber AIDA. Here, particles were produced from ozonolysis of single monoterpenes and aged by condensing OH-oxidation products. Two aerosol mass spectrometers (AMS) were used to measure the chemical composition of the particles. One of the instruments is equipped with a quadrupole mass spectrometer providing unit mass resolution. The second instrument contains a time-of-flight mass spectrometer and provides mass resolution sufficient to distinguish different fragments with the same nominal mass. Aerosol mass spectra obtained with these instruments are strongly fragmented due to electron impact ionization of the evaporated molecules. In addition, typical BSOA mass spectra are very similar to each other. In order to get a more detailed knowledge about the mass

  10. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

    Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three floral stages of a fig-wasp dependency mechanism: receptive, post pollinator and interfloral. Of 28 compounds detected, transcaryophyllene with trans-β-farnesene were the most important at the receptor stage, trans-caryophyllene was the most abundant at the post-pollinator stage, and isoprene was the most abundant in the interfloral stage. Alpinia kwangsiensis presents two morphologies for the reproductive parts of the flower. The "anaflexistyle" morphology has the flower style lowered in the

  11. Reversible and irreversible processing of biogenic olefins on acidic aerosols

    Directory of Open Access Journals (Sweden)

    J. Liggio

    2007-08-01

    Full Text Available Recent evidence has suggested that heterogeneous chemistry of oxygenated hydrocarbons, primarily carbonyls, plays a role in the formation of secondary organic aerosol (SOA; however, evidence is emerging that direct uptake of alkenes on acidic aerosols does occur and can contribute to SOA formation. In the present study, significant uptake of monoterpenes, oxygenated monoterpenes and sesquiterpenes to acidic sulfate aerosols is found under various conditions in a reaction chamber. Proton transfer mass spectrometry is used to quantify the organic gases, while an aerosol mass spectrometer is used to quantify the organic mass uptake and obtain structural information for heterogeneous products. Aerosol mass spectra are consistent with several mechanisms including acid catalyzed olefin hydration, cationic polymerization and organic ester formation, while measurable decreases in the sulfate mass on a per particle basis suggest that the formation of organosulfate compounds is also likely. A portion of the heterogeneous reactions appears to be reversible, consistent with reversible olefin hydration reactions. A slow increase in the organic mass after a fast initial uptake is attributed to irreversible reactions, consistent with polymerization and organosulfate formation. Uptake coefficients (γ were estimated for a fast initial uptake governed by the mass accommodation coefficient (α and ranged from 1×10-6–2.5×10−2. Uptake coefficients for a subsequent slower reactive uptake ranged from 1×10-7–1×10-4. These processes are estimated to potentially produce greater than 2.5 μg m−3 of SOA from the various biogenic hydrocarbons under atmospheric conditions, which can be highly significant given the large array of atmospheric olefins.

  12. Emissions of biogenic volatile organic compounds & their photochemical transformation

    Science.gov (United States)

    Yu, Zhujun; Hohaus, Thorsten; Tillmann, Ralf; Andres, Stefanie; Kuhn, Uwe; Rohrer, Franz; Wahner, Andreas; Kiendler-Scharr, Astrid

    2015-04-01

    Natural and anthropogenic activities emit volatile organic compounds (VOC) into the atmosphere. While it is known that land vegetation accounts for 90% of the global VOC emissions, only a few molecules' emission factors are understood. Through VOCs atmospheric oxidation intermediate products are formed. The detailed chemical mechanisms involved are insufficiently known to date and need to be understood for air quality management and climate change predictions. In an experiment using a PTR-ToF-MS with the new-built plant chamber SAPHIR-PLUS in Forschungszentrum Juelich, biogenic emissions of volatile organic compounds (BVOC) from Quercus ilex trees were measured. The BVOC emissions were dominated by monoterpenes, minor emissions of isoprene and methanol were also observed with the overall emission pattern typical for Quercus ilex trees in the growing season. Monoterpenes and isoprene emissions showed to be triggered by light. Additionally, their emissions showed clear exponential temperature dependence under constant light condition as reported in literature. As a tracer for leaf growth, methanol emission showed an abrupt increase at the beginning of light exposure. This is explained as instantaneous release of methanol produced during the night once stomata of leaves open upon light exposure. Emission of methanol showed a near linear increase with temperature in the range of 10 to 35 °C. BVOC were transferred from the plant chamber PLUS to the atmospheric simulation chamber SAPHIR, where their oxidation products from O3 oxidation were measured with PTR-ToF-MS. Gas phase oxidation products such as acetone and acetaldehyde were detected. A quantitative analysis of the data will be presented, including comparison of observations to the Master Chemical Mechanism model.

  13. Relationship between analgesia and turnover of brain biogenic amines.

    Science.gov (United States)

    Bensemana, D; Gascon, A L

    1978-10-01

    The analgesic activity of morphine, delta9THC, and sodium salicylate was studied concomitantly with changes in brainstem and cortex turnover of dopamine (DA), noradrenaline (NA), and serotonin (5HT). The results show that a correlation exists between the presence of analgesia and the increased turnover rates of the three biogenic amines. Morphine and sodium salicylate induced analgesia is accompanied by an increased turnover rate of all three biogenic amines; delta9THC-induced analgesia is accompanied by an increased turnover rate of DA and 5HT only. There is, however, no consistent relationship between the degree of analgesia and the degree of change in the turnover rates. The existence of the endogenous morphine-like substances, endorphines, may explain why morphine analgesia is distinct from that of delta9THC and sodium salicylate. The possible relationship between this morphine-like substance and biogenic amines is discussed.

  14. Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?

    Energy Technology Data Exchange (ETDEWEB)

    Paull, C.K.; Ussler, W. III; Borowski, W.S.

    1993-09-01

    Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.

  15. Voluntary drinking of ethanol by the rat: biogenic amines and possible underlying mechanism.

    Science.gov (United States)

    Messiha, F S

    1978-09-01

    The present study evaluates the possible relationship between certain biogenic amine metabolites-produced changes in voluntary drinking of ethyl alcohol (ET) solution by the rat and their in vivo effects on the enzymes primarily involved in the hepatic metabolism of ET, i.e., liver alcohol-(L-ADH) and aldehyde dehydrogenase (L-ALDH). In experiments on voluntary intake of ET solution by the rat, compounds selected were injected, 0.5 mM/kg, IP. Administration of vanillylmandelic acid (VMA) and 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) markedly reduced ET drinking. Similar significant effects were seen after administration of the neutral metabolites of the biogenic amines tested, after injection of metanephrine or 3-methoxy-4-hydroxyphenylpyruvic acid. Threodihydroxyphenylserine but not L-dopa reduced ET intake by the rat. Treatment with peripheral decarboxylase inhibitors, i.e., carbidopa, 50 mg/kg, IP, significantly reduced ET drinking as contrasted with nonsignificant decline in ET consumption following benserazide, 500 mg/kg, IP. In the biochemical study, short-term administration of the compounds selected produced varied effects on L-ADH and L-ADH. It is suggested that alteration of hepatic ADH by the compounds tested might account for the observation reduced ET drinking thereby, indicating the contribution of peripheral sources rather than central factors in mediating the behavioral effects studied.

  16. The irony of iron -- biogenic iron oxides as an iron source to the ocean

    Directory of Open Access Journals (Sweden)

    David eEmerson

    2016-01-01

    Full Text Available Primary productivity in at least a third of the sunlit open ocean is thought to be iron-limited. Primary sources of dissolved iron (dFe to the ocean are hydrothermal venting, flux from the sediments along continental margins, and airborne dust. This article provides a general review of sources of hydrothermal and sedimentary iron to the ocean, and speculates upon the role that iron-cycling microbes play in controlling iron dynamics from these sources. Special attention is paid to iron-oxidizing bacteria (FeOB that live by oxidizing iron and producing biogenic iron oxides as waste products. The presence and ubiquity of FeOB both at hydrothermal systems and in sediments is only beginning to be appreciated. The biogenic oxides they produce have unique properties that could contribute significantly to the dynamics of dFe in the ocean. Changes in the physical and chemical characteristics of the ocean due to climate change and ocean acidification will undoubtedly impact the microbial iron cycle. A better understanding of the contemporary role of microbes in the iron cycle will help in predicting how these changes could ultimately influence marine primary productivity.

  17. Biogenic gases in tropical floodplain river

    Directory of Open Access Journals (Sweden)

    Maria Victória Ramos Ballester

    2001-06-01

    Full Text Available Analysis of the distribution of biogenic gases in the floodplain of the Mogi-Guaçu River (São Paulo, Brazil enabled the establishment of a "redox hierarchy", in which the main channel was the most oxidizing environment, followed by Diogo Lake, with Infernão Lake having the most reducing conditions of the subsystems evaluated. Diogo Lake exported about 853.4 g C.m-2.year-1, of which, 14.6% was generated from methanogenesis and 36.7% by aerobic respiration. For Infernão Lake, these values were 2016 g C.m-2.year-1, 1.8 % and 41.5 %, respectively. Carbon export by these systems was predominantly in the form of CO2, which was responsible for the release of 728.78 g C.m-2.year-1 at Diogo Lake and 1979.72 g C.m-2. year-1 at Infernão Lake. Such patterns may result from the nature of the hydrological conditions, the action of the hydroperiod, and morphological characteristics of the environment.A análise da distribuição de gases biogênicos na planície de inundação do Rio Mogi Guaçu (São Paulo, Brasil possibilitou o estabelecimento de um gradiente redox para os sistemas aquáticos avaliados, em que o canal principal do rio apresentou-se como o ambiente mais oxidado, seguido da Lagoa do Diogo, e a Lagoa do Infernão apresentando as condições mais redutoras entre os ambientes em questão. A Lagoa do Diogo exporta um total de 853,4 g C.m-2.ano-1, do qual 14,6% é produzido pela metanogênese e 36,7% pela respiração aeróbia. Para a Lagoa do Infernão estes valores foram respectivamente de 2.016 g C.m-2.ano-1, 1,8% e de 41,5%. A exportação de carbono por estes sistemas é realizada, predominantemente na forma de CO2, nos valores de 728,78 g C.m-2.ano-1 para a Lagoa do Diogo e 1.979,72 g C.m-2.ano-1 para a Lagoa do Infernão. Estes padrões parecem estar relacionados com a natureza das condições hidrológicas, com a ação do hidroperíodo e com as características morfológicas do ambiente.

  18. Reaction of ozone with c5 and c6 biogenic volatile organic compounds

    Science.gov (United States)

    O Connor, M.; O Dwyer, M.; Wenger, J.

    2003-04-01

    REACTION OF OZONE WITH C5 AND C6 BIOGENIC VOLATILE ORGANIC COMPOUNDS M. O'Connor, M. O'Dwyer, J. Wenger CRAC-Centre for Research into Atmospheric Chemistry, Department of Chemistry, University College Cork, Ireland. jwenger@chemistry.ucc.ie Biogenic volatile organic compounds (BVOCs) account for around 90% of hydrocarbon emissionsinto the Earth's atmosphere. During the last ten years an increasing number of oxygenated BVOCs have also been detected in field measurement campaigns and plant emission studies. In particular a range of C5 and C6 oxygenates have been identifiedincluding compounds such as 1-penten-3-ol, E-2-hexenal and E-2-hexenyl acetate. The atmospheric impact of many of these compounds is largely unknown. The major atmospheric degradation processes for biogenic VOCs are gas-phase reaction with hydroxyl (OH) radicals, nitrate (NO3) radicals and ozone (O3). These reactions produce oxidized hydrocarbons, ozone and secondary organic aerosol and, as a result, exert a strong influence on the chemical compositionof the atmosphere. Although a number of studies have been made on the kinetics of the degradation of BVOCs, very few details are available concerning the reaction products and chemical mechanisms. In this work we have studied the reaction of O3 with a series of C5 unsaturated alcohols and C6 unsaturated aldehydes. Rate coefficients for these reactions have been studied using the relative rate method and gas-phase oxidation products have been identified using FTIR spectroscopy and PFBHA derivatisation coupled with GC-MS analysis. In addition secondary organic aerosol (SOA) formation has been studied as a function of humidity. The data obtained in this work will be used to further our knowledge of the atmospheric degradation of these naturally occurring compounds.

  19. Source of nutrient substrates for microbes in deep biosphere and characteristics of biogenic gas source rock

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    To understand the biogas formation in geological basins, the present work investigated the reactive organic matter in sediments of the Sanhu depression of Qaidam Basin, a prolific region of biogenic gases with a proved reserve of 300 bil steres. The ROC (reactive organic carbon) was obtained by ultrasonic extraction from sediment samples in the solution of 6 mol/L HCl and 5% K2SO4. To investigate the effect of early diagenesis, parts of the samples were heated at 80°C before extraction. The results showed that the ROC content at a constant temperature decreased with increasing burial depths, which should be attributed to the microbial consumption. For the same sample, the ROC content heated at 80°C was dramatically higher than the unheated. The increment of the ROC content for some samples was as high as 200% in the experiment. The dramatically increasing ROC by thermal action should be the major nutrient substrate for the deep biospheres in most geological basins. There is a positive correlation between the reactive organic carbon (ROC) and the traditional insoluble organic carbon (TOC), not only for its absolute content of the ROC, but also for the ’ROC’ produced in thermal action, all of these are clearly related with TOC. These data showed that higher abundance of organic matter can contribute more to the reactive organic matter, and is more favorable to the formation of biogenic gases. In the Sanhu depression of Qaidam Basin, more than 85% of the biogenic gas reserves occur in the lower layers (K5-K13) with a relatively high abundance of organic matter. The exploration has provided further evidence that deposits with higher abundance of organic matter are effective biogas source rocks.

  20. Use of biogenic sulfide for ZnS precipitation

    NARCIS (Netherlands)

    Esposito, G.; Veeken, A.; Weijma, J.; Lens, P.N.L.

    2006-01-01

    A 600 ml continuously stirred tank reactor was used to assess the performance of a zinc sulfide precipitation process using a biogenic sulfide solution (the effluent of a sulfate-reducing bioreactor) as sulfide source. In all experiments, a proportional-integral (PI) control algorithm was used to co

  1. Conditions allowing the formation of biogenic amines in cheese.

    NARCIS (Netherlands)

    Joosten, H.M.L.J.

    1988-01-01

    A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine formation may be observ

  2. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  3. Biogenic and synthetic high magnesium calcite - a review.

    Science.gov (United States)

    Long, Xia; Ma, Yurong; Qi, Limin

    2014-01-01

    Systematic studies on the Mg distributions, the crystal orientations, the formation mechanisms and the mechanical properties of biogenic high-Mg calcites in different marine organisms were summarized in detail in this review. The high-Mg calcites in the hard tissues of marine organisms mentioned generally own a few common features as follows. Firstly, the Mg distribution is not uniform in most of the minerals. Secondly, high-Mg calcite biominerals are usually composed of nanoparticles that own almost the same crystallographic orientations and thus they behave like single crystals or mesocrystals. Thirdly, the formation of thermodynamically unstable high-Mg calcites in marine organisms under mild conditions is affected by three key factors, that is, the formation of amorphous calcium (magnesium) carbonate precursor, the control of polymorph via biomolecules and the high Mg/Ca ratios in modern sea. Lastly, the existence of Mg ions in the Mg-containing calcite may improve the mechanical properties of biogenic minerals. Furthermore, the key progress in the synthesis of high-Mg calcites in the laboratory based on the formation mechanisms of the biogenic high-Mg calcites was reviewed. Many researchers have realized the synthesis of high-Mg calcites in the laboratory under ambient conditions with the help of intermediate amorphous phase, mixed solvents, organic/inorganic surfaces and soluble additives. Studies on the structural analysis and formation mechanisms of thermodynamically unstable biogenic high-Mg calcite minerals may shed light on the preparation of functional materials with enhanced mechanical properties.

  4. Influence of Thawing Methods and Storage Temperatures on Bacterial Diversity, Growth Kinetics, and Biogenic Amine Development in Atlantic Mackerel

    DEFF Research Database (Denmark)

    Onyang, S.; Palmadottir, H.; Tomason, T.;

    2016-01-01

    Limited knowledge is currently available on the influence of fish thawing and subsequent storage conditions on bacterial growth kinetics, succession, and diversity alongside the production of biogenic amines. This study aimed to address these factors during the thawing and subsequent storage...... time of hydrogen sulfide producing bacteria was significantly affected by both thawing methods, and further, the interaction between thawing and storage significantly affected the maximum growth rate of these bacteria. However, the maximum growth rate of Pseudomonas was higher during refrigerated......, and Pseudomonas. Maximum growth rate, population density, and lag time were fitted on the counts using the Baranyi model. The bacterial diversity and succession were based on sequencing of 16S rRNA amplicons, and biogenic amines were quantified on high-pressure liquid chromatography UV. The results show that lag...

  5. Preliminary investigation of biogenic gas production in Indonesian low rank coals and implications for a renewable energy source

    Science.gov (United States)

    Susilawati, Rita; Papendick, Sam L.; Gilcrease, Patrick C.; Esterle, Joan S.; Golding, Suzanne D.; Mares, Tennille E.

    2013-11-01

    Indonesia has abundant coal resources at depths suitable to contain substantial volumes of naturally occurring methane, which are currently being explored. Most Indonesian coals are thermally immature, but are composed of hydrogen-rich organic components that are presumed to make them excellent substrates for biogenic methane production. Gas isotope results from pilot wells in South Sumatra, reported in this study, are interpreted to indicate biogenic origins for the methane. Corresponding formation water samples were collected and incubated, and show the presence of indigenous microbial communities capable of producing methane from Indonesian and Australian coal. Although these results are only preliminary, they are promising and support the possibility of Indonesia developing bio renewable energy from coal seams.

  6. Effect of wine addition on microbiological characteristics, volatile molecule profiles and biogenic amine contents in fermented sausages.

    Science.gov (United States)

    Coloretti, Fabio; Tabanelli, Giulia; Chiavari, Cristiana; Lanciotti, Rosalba; Grazia, Luigi; Gardini, Fausto; Montanari, Chiara

    2014-03-01

    The aim was to evaluate the effect of wine addition during manufacturing of dry fermented sausages, in terms of safety aspects (biogenic amine accumulation), aroma profile and sensory characteristics. Three batches of salami were produced: without wine addition and with 7.5% or 15% (v/w) of white wine. The fermented sausages showed characteristics that can increase product diversification. Some of the sensory features (i.e. increased salty perception) can represent an important strategy because of the trend to reduce salt intake for health reasons. The presence of wine immediately reduced the pH and is a source of ethanol, which can have an inhibitory effect against undesirable microflora. The microbiological results observed regarding Enterobacteriaceae and enterococci were encouraging. The addition of wine did not negatively affect the ripening time or increase the presence of biogenic amines. The samples containing wine showed reduced concentrations of putrescine.

  7. Biostimulated uranium immobilization within aquifers – from bench scale to field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Kai-Uwe; Veeramani, Harish; Schofield, Eleanor J.; Sharp, Jonathan O.; Suvorova, Elena; Stubbs, Joanne E.; Lezama Pacheco, Juan S.; Barrows, Charles J.; Cerrato, Jose M.; Campbell, Kate M.; Yabusaki, Steven B.; Long, Philip E.; Bernier-Latmani, Rizlan; Giammar, Daniel E.; Bargar, John R.

    2011-12-29

    In situ bioremediation of uranium-contaminated aquifers through microbially catalyzed reduction of mobile U(VI) species can only be successful if the U(IV) products are immobilized over long time-scales. Although uraninite is known for its low solubility and has been produced in nano-particulate form by several species of metal- and sulfate-reducing bacteria in laboratory studies, little is known about the stability of biogenic U(IV) in the subsurface. Using an up-scaling approach, we investigated the chemical and environmental stability of biogenic UO₂ nano-solids. Our results show that diffusive limitations due to aquifer porosity and microstructure may retard uraninite corrosion. Corrosion was also retarded by adsorption or incorporation of manganese. On the other hand, U(VI) bioreduction in field sediments generated U(IV) that was more labile than biogenic UO₂.

  8. Modeling biogenic and anthropogenic secondary organic aerosol in China

    Science.gov (United States)

    Hu, Jianlin; Wang, Peng; Ying, Qi; Zhang, Hongliang; Chen, Jianjun; Ge, Xinlei; Li, Xinghua; Jiang, Jingkun; Wang, Shuxiao; Zhang, Jie; Zhao, Yu; Zhang, Yingyi

    2017-01-01

    A revised Community Multi-scale Air Quality (CMAQ) model with updated secondary organic aerosol (SOA) yields and a more detailed description of SOA formation from isoprene oxidation was applied to study the spatial and temporal distribution of SOA in China in the entire year of 2013. Predicted organic carbon (OC), elemental carbon and volatile organic compounds agreed favorably with observations at several urban areas, although the high OC concentrations in wintertime in Beijing were under-predicted. Predicted summer SOA was generally higher (10-15 µg m-3) due to large contributions of isoprene (country average, 61 %), although the relative importance varies in different regions. Winter SOA was slightly lower and was mostly due to emissions of alkane and aromatic compounds (51 %). Contributions of monoterpene SOA was relatively constant (8-10 %). Overall, biogenic SOA accounted for approximately 75 % of total SOA in summer, 50-60 % in autumn and spring, and 24 % in winter. The Sichuan Basin had the highest predicted SOA concentrations in the country in all seasons, with hourly concentrations up to 50 µg m-3. Approximately half of the SOA in all seasons was due to the traditional equilibrium partitioning of semivolatile components followed by oligomerization, while the remaining SOA was mainly due to reactive surface uptake of isoprene epoxide (5-14 %), glyoxal (14-25 %) and methylglyoxal (23-28 %). Sensitivity analyses showed that formation of SOA from biogenic emissions was significantly enhanced due to anthropogenic emissions. Removing all anthropogenic emissions while keeping the biogenic emissions unchanged led to total SOA concentrations of less than 1 µg m-3, which suggests that manmade emissions facilitated biogenic SOA formation and controlling anthropogenic emissions would result in reduction of both anthropogenic and biogenic SOA.

  9. Utilisation of biogenic waste through hydrothermal carbonisation; Nutzung biogener Reststoffe mit hydrothermaler Carbonisierung

    Energy Technology Data Exchange (ETDEWEB)

    Badoux, Francois [AVA-CO2, Zug (Switzerland)

    2011-03-15

    If deployed properly, biogenic residues and biomass, which could not be used for food production, may serve as a valuable resource, too. The preferred method to do so profitably is hydrothermal carbonization (HTC). The Swiss company AVA-CO2 brought this process to industrial maturity and recently presented an HTC plant in Karlsruhe. Research partner is the Karlsruhe Institute of Technology (KIT). The HTC method processes various types of wet and dry biomass into CO{sub 2}-neutral biocoal with high calorific value or biochar for soil improvement. The process, running at a pressure of 22-25 bar and temperatures of 210-220 C, is robust and exothermic. The industrial-size demonstration plant features a 14-cubic-meter reactor and processes up to 8,400 tons of biomass per year. A typical plant for the industry will consist of 6 to 12 reactors, and thus have an annual capacity of 50,000 up to 100,000 tons of biomass. Thanks to the modular principle, a plant can at any time be increased to any desired capacity level. The HTC plant developed by AVA-CO2 is reliable and can be seamlessly integrated into a client's continuous production processes. (orig.)

  10. The antibacterial and anti-biofouling performance of biogenic silver nanoparticles by Lactobacillus fermentum.

    Science.gov (United States)

    Zhang, Manying; Zhang, Kaisong; De Gusseme, Bart; Verstraete, Willy; Field, Robert

    2014-01-01

    Biofouling is a major challenge in the water industry and public health. Silver nanoparticles (AgNPs) have excellent antimicrobial properties and are considered to be a promising anti-biofouling agent. A modified method was used to produce small sized and well-dispersed biogenic silver nanoparticles with a mean size of ~6 nm (Bio-Ag0-6) using Lactobacillus fermentum. The morphology, size distribution, zeta potential and oxidation state of the silver were systematically characterized. Determination of minimal inhibitory and bactericidal concentration results revealed that biogenic silver Bio-Ag(0-6) can effectively suppress the growth of the test bacteria. Additionally, the inhibition effects of Bio-Ag(0-6) on biofilm formation and on established biofilms were evaluated using P. aeruginosa (ATCC 27853) as the model bacterium. The results from microtiter plates and confocal laser scanning microscopy demonstrated that Bio-Ag(0-6) not only exhibited excellent antibacterial performance but also could control biofilm formation and induce detachment of the bulk of P. aeruginosa biofilms leaving a small residual matrix.

  11. Assessing the potential for using biogenic calcites as dosemeters for luminescence dating

    Energy Technology Data Exchange (ETDEWEB)

    Duller, G.A.T. [Institute of Geography and Earth Sciences, Aberystwyth University, Ceredigion, SY23 3DB (United Kingdom)], E-mail: ggd@aber.ac.uk; Penkman, K.E.H. [BioArCh, Department of Chemistry, University of York, YO10 5DD (United Kingdom); Wintle, A.G. [Institute of Geography and Earth Sciences, Aberystwyth University, Ceredigion, SY23 3DB (United Kingdom)

    2009-05-15

    Calcium carbonate emits an intense thermoluminescence (TL) signal and previous work has explored the potential of using this signal to date both inorganic carbonates such as limestones and stalagmites and biogenic calcite produced by marine organisms. Luminescence analysis of biogenic calcites directly dates the secretion of the mineral by the organism and is therefore not reliant upon exposure of the sample to daylight. A method is outlined for using the TL signals from slug plates, from the Limacidae family, and opercula from the snail Bithynia tentaculata to construct a single-aliquot regenerative-dose growth curve. Analysis of slug plates from a number of Quaternary sites show that the equivalent dose (D{sub e}) of a late Holocene sample is close to zero and that the D{sub e} increases with age over the last 500 ka. The TL signal from snail opercula is shown to increase up to doses over 4000 Gy. Replicate measurements from 16 opercula from a site {approx}220 ka show a broad distribution. Potential causes of this scatter are discussed along with recommendations about how it could be reduced. The major challenge which remains to be solved before slug plates or snail opercula could be used to calculate ages is to develop methods for calculating the dose rate received during burial.

  12. Succinylated Octopamine Ascarosides and a New Pathway of Biogenic Amine Metabolism in Caenorhabditis elegans*

    Science.gov (United States)

    Artyukhin, Alexander B.; Yim, Joshua J.; Srinivasan, Jagan; Izrayelit, Yevgeniy; Bose, Neelanjan; von Reuss, Stephan H.; Jo, Yeara; Jordan, James M.; Baugh, L. Ryan; Cheong, Micheong; Sternberg, Paul W.; Avery, Leon; Schroeder, Frank C.

    2013-01-01

    The ascarosides, small-molecule signals derived from combinatorial assembly of primary metabolism-derived building blocks, play a central role in Caenorhabditis elegans biology and regulate many aspects of development and behavior in this model organism as well as in other nematodes. Using HPLC-MS/MS-based targeted metabolomics, we identified novel ascarosides incorporating a side chain derived from succinylation of the neurotransmitter octopamine. These compounds, named osas#2, osas#9, and osas#10, are produced predominantly by L1 larvae, where they serve as part of a dispersal signal, whereas these ascarosides are largely absent from the metabolomes of other life stages. Investigating the biogenesis of these octopamine-derived ascarosides, we found that succinylation represents a previously unrecognized pathway of biogenic amine metabolism. At physiological concentrations, the neurotransmitters serotonin, dopamine, and octopamine are converted to a large extent into the corresponding succinates, in addition to the previously described acetates. Chemically, bimodal deactivation of biogenic amines via acetylation and succinylation parallels posttranslational modification of proteins via acetylation and succinylation of l-lysine. Our results reveal a small-molecule connection between neurotransmitter signaling and interorganismal regulation of behavior and suggest that ascaroside biosynthesis is based in part on co-option of degradative biochemical pathways. PMID:23689506

  13. Succinylated octopamine ascarosides and a new pathway of biogenic amine metabolism in Caenorhabditis elegans.

    Science.gov (United States)

    Artyukhin, Alexander B; Yim, Joshua J; Srinivasan, Jagan; Izrayelit, Yevgeniy; Bose, Neelanjan; von Reuss, Stephan H; Jo, Yeara; Jordan, James M; Baugh, L Ryan; Cheong, Micheong; Sternberg, Paul W; Avery, Leon; Schroeder, Frank C

    2013-06-28

    The ascarosides, small-molecule signals derived from combinatorial assembly of primary metabolism-derived building blocks, play a central role in Caenorhabditis elegans biology and regulate many aspects of development and behavior in this model organism as well as in other nematodes. Using HPLC-MS/MS-based targeted metabolomics, we identified novel ascarosides incorporating a side chain derived from succinylation of the neurotransmitter octopamine. These compounds, named osas#2, osas#9, and osas#10, are produced predominantly by L1 larvae, where they serve as part of a dispersal signal, whereas these ascarosides are largely absent from the metabolomes of other life stages. Investigating the biogenesis of these octopamine-derived ascarosides, we found that succinylation represents a previously unrecognized pathway of biogenic amine metabolism. At physiological concentrations, the neurotransmitters serotonin, dopamine, and octopamine are converted to a large extent into the corresponding succinates, in addition to the previously described acetates. Chemically, bimodal deactivation of biogenic amines via acetylation and succinylation parallels posttranslational modification of proteins via acetylation and succinylation of L-lysine. Our results reveal a small-molecule connection between neurotransmitter signaling and interorganismal regulation of behavior and suggest that ascaroside biosynthesis is based in part on co-option of degradative biochemical pathways.

  14. Tyrosine-containing peptides are precursors of tyramine produced by Lactobacillus plantarum strain IR BL0076 isolated from wine

    Directory of Open Access Journals (Sweden)

    Bonnin-Jusserand Maryse

    2012-09-01

    Full Text Available Abstract Background Biogenic amines are molecules with allergenic properties. They are found in fermented products and are synthesized by lactic acid bacteria through the decarboxylation of amino acids present in the food matrix. The concentration of biogenic amines in fermented foodstuffs is influenced by many environmental factors, and in particular, biogenic amine accumulation depends on the quantity of available precursors. Enological practices which lead to an enrichment in nitrogen compounds therefore favor biogenic amine production in wine. Free amino acids are the only known precursors for the synthesis of biogenic amines, and no direct link has previously been demonstrated between the use of peptides by lactic acid bacteria and biogenic amine synthesis. Results Here we demonstrate for the first time that a Lactobacillus plantarum strain isolated from a red wine can produce the biogenic amine tyramine from peptides containing tyrosine. In our conditions, most of the tyramine was produced during the late exponential growth phase, coinciding with the expression of the tyrDC and tyrP genes. The DNA sequences of tyrDC and tyrP in this strain share 98% identity with those in Lactobacillus brevis consistent with horizontal gene transfer from L. brevis to L. plantarum. Conclusion Peptides amino acids are precursors of biogenic amines for Lactobacillus plantarum strain IR BL0076.

  15. Probing tRNA interaction with biogenic polyamines.

    Science.gov (United States)

    Ouameur, Amin Ahmed; Bourassa, Philippe; Tajmir-Riahi, Heidar-Ali

    2010-10-01

    Biogenic polyamines are found to modulate protein synthesis at different levels. This effect may be explained by the ability of polyamines to bind and influence the secondary structure of tRNA, mRNA, and rRNA. We report the interaction between tRNA and the three biogenic polyamines putrescine, spermidine, spermine, and cobalt(III)hexamine at physiological conditions, using FTIR spectroscopy, capillary electrophoresis, and molecular modeling. The results indicated that tRNA was stabilized at low biogenic polyamine concentration, as a consequence of polyamine interaction with the backbone phosphate group. The main tRNA reactive sites for biogenic polyamine at low concentration were guanine-N7/O6, uracil-O2/O4, adenine-N3, and 2'OH of the ribose. At high polyamine concentration, the interaction involves guanine-N7/O6, adenine-N7, uracil-O2 reactive sites, and the backbone phosphate group. The participation of the polycation primary amino group, in the interaction and the presence of the hydrophobic contact, are also shown. The binding affinity of biogenic polyamine to tRNA molecule was in the order of spermine > spermidine > putrescine with K(Spm) = 8.7 × 10(5) M(-1), K(Spd) = 6.1 × 10(5) M(-1), and K(Put) = 1.0 × 10(5) M(-1), which correlates with their positively charged amino group content. Hill analysis showed positive cooperativity for the biogenic polyamines and negative cooperativity for cobalt-hexamine. Cobalt(III)hexamine contains high- and low-affinity sites in tRNA with K(1) = 3.2 × 10(5) M(-1) and K(2) = 1.7 × 10(5) M(-1), that have been attributed to the interactions with guanine-N7 sites and the backbone PO(2) group, respectively. This mechanism of tRNA binding could explain the condensation phenomenon observed at high Co(III) content, as previously shown in the Co(III)-DNA complexes.

  16. Binding to extracellular matrix proteins and formation of biogenic amines by food-associated coagulase-negative staphylococci.

    Science.gov (United States)

    Seitter, Marion; Geng, Bettina; Hertel, Christian

    2011-02-28

    In connection with a study on the DNA microarray based detection of genes involved in safety and technologically relevant properties (Seitter (née Resch) et al., 2011), food-associated coagulase-negative staphylococci (CNS) were investigated phenotypically with regard to their ability to bind to the extracellular matrix proteins (ECM) and to produce biogenic amines. The properties have been shown to be involved in the colonization of injured tissue and invasion into host cells as well as in pharmacologic effects on humans, respectively. The CNS exhibited a low, but nevertheless clearly measurable ECM binding capacity, except for strains of Staphylococcus equorum and Staphylococcus succinus, which show a comparable or even higher binding to fibrinogen and fibronectin than that of the control strain Staphylococcus aureus Cowan. Formation of biogenic amines could be often detected in S. carnosus, S. condimenti and S. strains, but rarely in S. equorum and not in S. succinus and S. xylosus strains. Mostly, 2-phenylethylamine, tyramine and tryptamine were formed by resting cells in amounts 100 mg/l) of 2-phenylethylamine and putrescine. This study confirmed the need of consideration of ECM binding and biogenic amine formation in the safety assessment of CNS used in the production of fermented foods.

  17. [Metabolism of various biogenic amines in acute viral neuroinfections].

    Science.gov (United States)

    Martynenko, I N; Shchegoleva, R A; Ponomarenko, V P; Leshchinskaia, E V; Kodkind, G Kh

    1983-01-01

    The metabolism of biogenic amines was examined in 62 patients with various acute viral neuroinfections. The control group consisted of 57 persons. Depending on the process character and disease period variations of the levels of serotonin, 5-hydroxyindolylacetic acid, coeruloplasmin and histamine were discovered. A comparison of the results obtained with the clinical course of the diseases revealed a certain correlation, especially in patients with acute meningoencephalitis.

  18. Ocean acidification can mediate biodiversity shifts by changing biogenic habitat

    Science.gov (United States)

    Sunday, Jennifer M.; Fabricius, Katharina E.; Kroeker, Kristy J.; Anderson, Kathryn M.; Brown, Norah E.; Barry, James P.; Connell, Sean D.; Dupont, Sam; Gaylord, Brian; Hall-Spencer, Jason M.; Klinger, Terrie; Milazzo, Marco; Munday, Philip L.; Russell, Bayden D.; Sanford, Eric; Thiyagarajan, Vengatesen; Vaughan, Megan L. H.; Widdicombe, Stephen; Harley, Christopher D. G.

    2017-01-01

    The effects of ocean acidification (OA) on the structure and complexity of coastal marine biogenic habitat have been broadly overlooked. Here we explore how declining pH and carbonate saturation may affect the structural complexity of four major biogenic habitats. Our analyses predict that indirect effects driven by OA on habitat-forming organisms could lead to lower species diversity in coral reefs, mussel beds and some macroalgal habitats, but increases in seagrass and other macroalgal habitats. Available in situ data support the prediction of decreased biodiversity in coral reefs, but not the prediction of seagrass bed gains. Thus, OA-driven habitat loss may exacerbate the direct negative effects of OA on coastal biodiversity; however, we lack evidence of the predicted biodiversity increase in systems where habitat-forming species could benefit from acidification. Overall, a combination of direct effects and community-mediated indirect effects will drive changes in the extent and structural complexity of biogenic habitat, which will have important ecosystem effects.

  19. On Mineral Retrosynthesis of a Complex Biogenic Scaffold

    Directory of Open Access Journals (Sweden)

    Ashit Rao

    2017-03-01

    Full Text Available Synergistic relations between organic molecules and mineral precursors regulate biogenic mineralization. Given the remarkable material properties of the egg shell as a biogenic ceramic, it serves as an important model to elucidate biomineral growth. With established roles of complex anionic biopolymers and a heterogeneous organic scaffold in egg shell mineralization, the present study explores the regulation over mineralization attained by applying synthetic polymeric counterparts (polyethylene glycol, poly(acrylic acid, poly(aspartic acid and poly(4-styrenesulfonic acid-co-maleic acid as additives during remineralization of decalcified eggshell membranes. By applying Mg2+ ions as a co-additive species, mineral retrosynthesis is achieved in a manner that modulates the polymorph and structure of mineral products. Notable features of the mineralization process include distinct local wettability of the biogenic organic scaffold by mineral precursors and mineralization-induced membrane actuation. Overall, the form, structure and polymorph of the mineralization products are synergistically affected by the additive and the content of Mg2+ ions. We also revisit the physicochemical nature of the biomineral scaffold and demonstrate the distinct spatial distribution of anionic biomolecules associated with the scaffold-mineral interface, as well as highlight the hydrogel-like properties of mammillae-associated macromolecules.

  20. Biogenic amines in rhizobia and legume root nodules.

    Science.gov (United States)

    Fujihara, Shinsuke

    2009-01-01

    Root-nodule bacteria (rhizobia) are of great importance for nitrogen acquisition through symbiotic nitrogen fixation in a wide variety of leguminous plants. These bacteria differ from most other soil microorganisms by taking dual forms, i.e. a free-living form in soils and a symbiotic form inside of host legumes. Therefore, they should have a versatile strategy for survival, whether inhabiting soils or root nodules formed through rhizobia-legume interactions. Rhizobia generally contain large amounts of the biogenic amine homospermidine, an analog of spermidine which is an essential cellular component in most living systems. The external pH, salinity and a rapid change in osmolarity are thought to be significant environmental factors affecting the persistence of rhizobia. The present review describes the regulation of homospermidine biosynthesis in response to environmental stress and its possible functional role in rhizobia. Legume root nodules, an alternative habitat of rhizobia, usually contain a variety of biogenic amines besides homospermidine and the occurrence of some of these amines is closely associated with rhizobial infections. In the second half of this review, novel biogenic amines found in certain legume root nodules and the mechanism of their synthesis involving cooperation between the rhizobia and host legume cells are also described.

  1. BAECC Biogenic Aerosols - Effects on Clouds and Climate

    Energy Technology Data Exchange (ETDEWEB)

    Petäjä, Tuukka [Univ. of Helsinki (Finland); Moisseev, Dmitri [Univ. of Helsinki (Finland); Sinclair, Victoria [Univ. of Helsinki (Finland); O' Connor, Ewan J. [Finnish Meteorological Institute, Helsinki (Finland); Manninen, Antti J. [Univ. of Helsinki (Finland); Levula, Janne [Univ. of Helsinki (Finland); Väänänen, Riikka [Univ. of Helsinki (Finland); Heikkinen, Liine [Univ. of Helsinki (Finland); Äijälä, Mikko [Univ. of Helsinki (Finland); Aalto, Juho [Univ. of Helsinki (Finland); Bäck, Jaana [University of Helsinki, Finland

    2015-11-01

    Biogenic Aerosols - Effects on Clouds and Climate (BAECC)”, featured the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program’s 2nd Mobile Facility (AMF2) in Hyytiälä, Finland. It operated for an 8-month intensive measurement campaign from February to September 2014. The main research goal was to understand the role of biogenic aerosols in cloud formation. One of the reasons to perform BAECC study in Hyytiälä was the fact that it hosts SMEAR-II (Station for Measuring Forest Ecosystem-Atmosphere Relations), which is one of the world’s most comprehensive surface in-situ observation sites in a boreal forest environment. The station has been measuring atmospheric aerosols, biogenic emissions and an extensive suite of parameters relevant to atmosphere-biosphere interactions continuously since 1996. The BAECC enables combining vertical profiles from AMF2 with surface-based in-situ SMEAR-II observations and allows the processes at the surface to be directly related to processes occurring throughout the entire tropospheric column. With the inclusion of extensive surface precipitation measurements, and intensive observation periods involving aircraft flights and novel radiosonde launches, the complementary observations of AMF2 and SMEAR-II provide a unique opportunity for investigating aerosol-cloud interactions, and cloud-to-precipitation processes. The BAECC dataset will initiate new opportunities for evaluating and improving models of aerosol sources and transport, cloud microphysical processes, and boundary-layer structures.

  2. Time Resolved Measurements of Primary Biogenic Aerosol Particles in Amazonia

    Science.gov (United States)

    Wollny, A. G.; Garland, R.; Pöschl, U.

    2009-04-01

    Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the Amazonian Aerosol Characterization Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. This presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 µm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as "viable aerosols" or "fluorescent bioparticles" (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. Data from the UVAPS were averaged over 5 minute time intervals. The presence of bioparticles in the observed size range has been

  3. Rainforest Aerosols as Biogenic Nuclei of Clouds and Precipitation in the Amazon

    Science.gov (United States)

    Pöschl, U.; Martin, S. T.; Sinha, B.; Chen, Q.; Gunthe, S. S.; Huffman, J. A.; Borrmann, S.; Farmer, D. K.; Garland, R. M.; Helas, G.; Jimenez, J. L.; King, S. M.; Manzi, A.; Mikhailov, E.; Pauliquevis, T.; Petters, M. D.; Prenni, A. J.; Roldin, P.; Rose, D.; Schneider, J.; Su, H.; Zorn, S. R.; Artaxo, P.; Andreae, M. O.

    2010-09-01

    The Amazon is one of the few continental regions where atmospheric aerosol particles and their effects on climate are not dominated by anthropogenic sources. During the wet season, the ambient conditions approach those of the pristine pre-industrial era. We show that the fine submicrometer particles accounting for most cloud condensation nuclei are predominantly composed of secondary organic material formed by oxidation of gaseous biogenic precursors. Supermicrometer particles, which are relevant as ice nuclei, consist mostly of primary biological material directly released from rainforest biota. The Amazon Basin appears to be a biogeochemical reactor, in which the biosphere and atmospheric photochemistry produce nuclei for clouds and precipitation sustaining the hydrological cycle. The prevailing regime of aerosol-cloud interactions in this natural environment is distinctly different from polluted regions.

  4. BIOGENIC AMINE CONTENT IN “PECORINO DEL PARCO DI MIGLIARINO - SAN ROSSORE”

    Directory of Open Access Journals (Sweden)

    F. Forzale

    2011-01-01

    Full Text Available Biogenic amines (BAs can be naturally present in several foods. They are mainly produced in large amounts by amino acid decarboxylases activity of bacteria. The BAs content has been associated to the quality of raw material and to fermentation or spoilage processes. The aim of the present study was to asses the content of BAs (single and total value in the core and in the external part of a Tuscan traditional pecorino cheese. Sixteen “Pecorino del Parco di Migliarino-San Rossore” cheeses belonging to same batch were tested during ripening time, up to 5 months. BAs content was analyzed by an HPLC-UV method. The BAs content was significantly higher in the core than in the external part. Tyramine was the amine most frequently detected and largely quantized, followed by putrescine, histamine and cadaverine.

  5. Evaluation of ELISA screening test for detecting aflatoxin in biogenic dust samples

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.T.

    1996-05-01

    Aflatoxin is a carcinogenic chemical that is sometimes produced when agricultural commodities are infested by the fungi Aspergillus flavus and A. Parasiticus. Aflatoxin has been found to be present in air samples taken around persons handling materials likely to be contaminated. The purpose of this investigation was to demonstrate the feasibility of using an Enzyme Linked Immunosorbent Assay (ELISA) test kit that was developed to screen for aflatoxin in bulk agricultural commodities, to an air sample. Samples were taken from two environments likely to be contaminated with aflatoxin, a dairy farm feed mixing operation and a peanut bagging operation. The dust collected from these environments was considered to be biogenic, in that it originated primarily from biological materials.

  6. Discovery Prospects for a Biogenic Supernova Signature

    CERN Document Server

    Bishop, Shawn

    2010-01-01

    Within the universe, the astrophysical sites responsible for the production of radioactive 60Fe, of half life 2.62 Myr, are primarily confined to two: Type 1a supernovae and massive stars that end their lives as Type II supernovae. Approximately 2.8 Myr before the present, our planet was subjected to the debris of a supernova explosion. The terrestrial proxy for this event was the discovery of live atoms of 60Fe in a deep sea ferromanganese crust, from which the terrestrial flux of supernova 60Fe was deduced. The signature for this supernova event should also be contained in microfossils produced by magnetotactic bacteria extant at the time of the Earth-supernova interaction. Using estimates for the terrestrial supernova 60Fe flux, combined with our empirically derived microfossil concentrations of a deep sea drill core, we deduce a conservative estimate of the 60Fe fraction as 60Fe/Fe = 3.6 x 10^{-15}; this value sits comfortably within the sensitivity limit of present accelerator mass spectrometry capabilit...

  7. Humidity-dependent phase state of SOA particles from biogenic and anthropogenic precursors

    Directory of Open Access Journals (Sweden)

    E. Saukko

    2012-02-01

    Full Text Available The physical phase state (solid, semi-solid, or liquid of secondary organic aerosol (SOA particles has important implications for a number of atmospheric processes. We report the phase state of SOA particles spanning a wide range of oxygen to carbon ratios (O/C, used here as a surrogate for SOA oxidation level, produced in a flow tube reactor by photo-oxidation of various atmospherically relevant surrogate anthropogenic and biogenic volatile organic compounds (VOCs. The phase state of laboratory-generated SOA was determined by the particle bounce behavior after inertial impaction on a polished steel substrate. The measured bounce fraction was evaluated as a function of relative humidity and SOA oxidation level (O/C measured by an Aerodyne high resolution time of flight aerosol mass spectrometer (HR-ToF AMS.

    The main findings of the study are: (1 Biogenic and anthropogenic SOA particles are found to be solid or semi-solid until a relative humidity of at least 50 % RH at impaction is reached. (2 Long-chain alkanes produce liquid SOA particles when generated at low oxidation level of O/C<0.2, but at higher oxidation levels they solidify. (3 Increasing sulphuric acid (H2SO4 within the SOA particles reduces the threshold of humidity-induced phase changes. (4 The bounce behavior of the various SOA systems did not show a consistent linear relationship with the particle O/C. Rather, the molar mass of the gas-phase VOC precursor showed a positive correlation with the resistance to the RH-induced phase change of the formed SOA particles.

  8. Distribution and accumulation of biogenic silica in the intertidal sediments of the Yangtze Estuary

    Institute of Scientific and Technical Information of China (English)

    HOU Lijun; LIU Min; XU Shiyuan; YAN Huimin; OU Dongni; CHENG Shubo; LIN Xiao

    2008-01-01

    Sedimentary biogenic silica is known to be all important parameter to understand biogeochemical processes and paleoenviromental records in estuarine and coastal ecosystems. Consequently, it is of great significance to investigate accumulation and distribution of biogenic silica in sediments. The two-step mild acid-mild alkaline extraction procedure was used to leach biogenic silica and its early diagenetic products in intertidal sediments of the Yangtze Estuary. The results showed that total biogenic silica(t-BSi)in the intertidal sediments varied from 237. 7-419. 4 μmol Si/g. while the mild acid leachable silica(Si-HCl)and the mild alkaline leachable silica(Si-Alk)were in the range of 25. 1-72. 9μmol Si/g and 208. 1-350. 4 μmol Si/g. respectively. Significant correlations were observed for the grain size distributions of sediments and different biogenic silica pools in intertidal sediments. This confirms that grain size distribution Can significantly affect biogenic silica contents in sediments. Close relationships of biogenic silica with organic carbon and nitrogen Were also found, reflecting that there is a strong coupling between biogenic silica and organic matter biogeochemical cycles in the intertidal system of the Yangtze Estuary. Additionally, the early diagenetic changes of biogenic silica in sediments are discussed in the present study.

  9. Control of biogenic amines in fermented sausages: role of starter cultures

    Directory of Open Access Journals (Sweden)

    Mariluz eLatorre-Moratalla

    2012-05-01

    Full Text Available Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

  10. Control of biogenic amines in fermented sausages: role of starter cultures.

    Science.gov (United States)

    Latorre-Moratalla, M L; Bover-Cid, Sara; Veciana-Nogués, M T; Vidal-Carou, M C

    2012-01-01

    Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

  11. Measurements of Biogenic and Anthropogenic Ozone and Aerosol Precursors during the SENEX (Southeast Nexus) Campaign 2013

    Science.gov (United States)

    Warneke, C.; Trainer, M.; De Gouw, J. A.

    2013-12-01

    Natural emissions of ozone and aerosol precursor gases such as isoprene and monoterpenes are the highest in the southeast of the U.S. and rival those found in tropical forests. In addition, anthropogenic emissions are significant in the Southeast and photochemistry is rapid. The southeast U.S. has not warmed like other parts of the U.S. in response to global climate change, and the temperature anomaly has been suggested to be related to aerosols derived from a combination of anthropogenic and biogenic precursors. The NOAA SENEX aircraft campaign took place in June-July 2013 in the southeast U.S. as part of the Southeast Atmosphere Study (SAS). The NOAA WP-3 aircraft conducted 20 research flights between May 27 and July 10, 2013 based out of Smyrna, TN. To investigate the combination of anthropogenic and biogenic emissions several flights were designed to follow the emissions of cities and power plants as they are transported over forested regions in the Southeast. For example, over-flights of Atlanta, Birmingham and Nashville were performed and the plumes were followed to the forested areas with high isoprene and monoterpene emissions. The same was done for several power plants such as EC Gaston, Scherer and Johnsonville. In the anthropogenic plumes, effects such as the modulation of the isoprene chemistry by high NOx and particle formation and growth were investigated. The same strategy was used for three nighttime flights over Atlanta, Birmingham and the New Madrid and White Bluff power plants. Flights over and downwind of St Lois and Indianapolis were used as a contrast in areas with smaller biogenic emissions. Other anthropogenic emissions sources that were investigated during SENEX included bio refineries, paper mills, coalmines, poultry and pork farming. Also biomass burning emissions were observed during one daytime and one nighttime flight. Another focus of the SENEX campaign was to determine the emissions of natural gas and oil production from the

  12. Biogenic syngenetic pyrite from tuffaceous sedimentary RF3-V rocks

    Science.gov (United States)

    Kozyreva, Irina; Nikulova, Natalia

    2015-04-01

    Biogenic framboidal pyrite was found in intraformational tuffaceous sedimentary gravelites, within basic volcanites (RF3-V) in Subpolar Urals (Sablya Ridge). Pyrite grains (Fe 44.07-44,33, S 50.22-53.31 wt. %) are composed of ball-like microconcretions, sometimes intergrown with crystals of pentagondodecahedron and cubic habit. The microconcretions (20 to 40 mcm) are roundish and composed of microcrystals, which end faces form spherical surface. The nuclei of the microconcretions are represented by frambohedrons 4-5 mcm in size, which are pyritized cells of sulphate-reducing colonial coccoid microfossils. The formation of the frambohedrons occurred synchronously to sedimentation in stagnant reducing environment at interaction of biogenic hydrogen sulphide with water-dissolved iron. The biogenic hydrogen sulphide is reduced by microorganisms in the conditions of free and unrestricted access of dissolved sulphate ions sourced from sulphur of fumarole gases. Iron came from washed-out basic volcanites. The growth of outer radial parts of microconcretions occurred during compaction of sediments in diagenetic stage. The quantity of dissolved sulphate and iron during pyrite formation exceeded possibilitites of bacterial "starters" which resulted in the formation of pyrites of other morphological varieties. This is confirmed by the accretion of concentric rays of the concretions and cubic microcrystals of pyrite in the aggregate grains. The formation of tuffaceous sediments occurred during temporary decrease of volcanic activity in a continuous linear water flow with stagnant areas composed of water-displaced pebbles from underlying metaterrigenous rocks (RF 1-2), which were exposed beyond the development area of volcanic strata, unchanged clasts of recent and synchronously formed basic and medium volcanites with participation of air-driven ashes and influence of volcanic gases in the presence of sulphate-reducing bacteria. The work is financially supported by the Program

  13. Biogenic influence on cloud microphysics over the global ocean

    Directory of Open Access Journals (Sweden)

    A. Lana

    2012-02-01

    Full Text Available Aerosols have a large potential to influence climate through their effects on the microphysics and optical properties of clouds and, hence, on the Earth's radiation budget. Aerosol-cloud interactions have been intensively studied in polluted air, but the possibility that the marine biosphere plays a role in regulating cloud brightness in the pristine oceanic atmosphere remains largely unexplored. We used 9 yr of global satellite data and ocean climatologies to derive parameterizations of (a production fluxes of sulfur aerosols formed by the oxidation of the biogenic gas dimethylsulfide emitted from the sea surface; (b production fluxes of secondary organic aerosols from biogenic organic volatiles; (c emission fluxes of biogenic primary organic aerosols ejected by wind action on sea surface; and (d emission fluxes of sea salt also lifted by the wind upon bubble bursting. Series of global weekly estimates of these fluxes were correlated to series of cloud droplet effective radius data derived from satellite (MODIS. Similar analyses were conducted in more detail at 6 locations spread among polluted and clean regions of the oceanic atmosphere. The outcome of the statistical analysis was that negative correlation was common at mid and high latitude for sulfur and organic secondary aerosols, indicating both might be important in seeding cloud droplet activation. Conversely, primary aerosols (organic and sea salt showed more variable, non-significant or positive correlations, indicating that, despite contributing to large shares of the marine aerosol mass, they are not major drivers of the variability of cloud microphysics. Uncertainties and synergisms are discussed, and recommendations of research needs are given.

  14. Post-speleogenetic biogenic modification of Gomantong Caves, Sabah, Borneo

    Science.gov (United States)

    Lundberg, Joyce; McFarlane, Donald A.

    2012-07-01

    The Gomantong cave system of eastern Sabah, Malaysia, is well-known as an important site for harvesting edible bird-nests and, more recently, as a tourist attraction. Although the biology of the Gomantong system has been repeatedly studied, very little attention has been given to the geomorphology. Here, we report on the impact of geobiological modification in the development of the modern aspect of the cave, an important but little recognized feature of tropical caves. Basic modeling of the metabolic outputs from bats and birds (CO2, H2O, heat) reveals that post-speleogenetic biogenic corrosion can erode bedrock by between ~ 3.0 mm/ka (1 m/~300 ka) and ~ 4.6 mm/ka (1 m/~200 ka). Modeling at high densities of bats yields rates of corrosion of ~ 34 mm/ka (or 1 m/~30 ka). Sub-aerial corrosion creates a previously undescribed speleological feature, the apse-flute, which is semicircular in cross-section and ~ 80 cm wide. It is vertical regardless of rock properties, developing in parallel but apparently completely independently, and often unbroken from roof to floor. They end at a blind hemi-spherical top with no extraneous water source. Half-dome ceiling conch pockets are remnants of previous apse-fluting. Sub-cutaneous corrosion creates the floor-level guano notch formed by organic acid dissolution of bedrock in contact with guano. Speleogenetic assessment suggests that as much as 70-95% of the total volume of the modern cave may have been opened by direct subaerial biogenic dissolution and biogenically-induced collapse, and by sub-cutaneous removal of limestone, over a timescale of 1-2 Ma.

  15. Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)

    Science.gov (United States)

    Koppmann, R.; Hoffmann, T.; Kesselmeier, J.; Schatzmann, M.

    Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in Jülich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.

  16. Genentech/BiogenIdec递交Rituxan治疗CLL的申请

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Genentech和Biogen Idec公司称已向美国食品和药物管理局(FDA)递交了两份补充生物制品许可证申请(sBLAs),申请Rituxan(rituximab)(Ⅰ)联合标准化疗方案用于初洽或已治慢性淋巴细胞白血病(CLL)。如获许可,公司将申请优先审查。

  17. Low-order models of biogenic ocean mixing

    Science.gov (United States)

    Dabiri, J. O.; Rosinelli, D.; Koumoutsakos, P.

    2009-12-01

    Biogenic ocean mixing, the process whereby swimming animals may affect ocean circulation, has primarily been studied using order-of-magnitude theoretical estimates and a small number of field observations. We describe numerical simulations of arrays of simplified animal shapes migrating in inviscid fluid and at finite Reynolds numbers. The effect of density stratification is modeled in the fluid dynamic equations of motion by a buoyancy acceleration term, which arises due to perturbations to the density field by the migrating bodies. The effects of fluid viscosity, body spacing, and array configuration are investigated to identify scenarios in which a meaningful contribution to ocean mixing by swimming animals is plausible.

  18. PROSPECTS OF MODIFICATION OF BALNEOLOGICAL REMEDIES WITH BIOGENEOUS METALLS NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    M. B. Mamuchieva

    2015-01-01

    Full Text Available The article considers the issues of mineral waters modification with biogeneous metals nanoparticles, since they have extremely important meaning for human's organism and their production in green and biologically compliant form is hard to overestimate. Russian scientists discovered low toxicity of these nanomaterials. So the use of biogeneuos metals in form of nanoparticles allows lowering of their toxicity compared with its use in forms of ions.

  19. Extracellular proteins limit the dispersal of biogenic nanoparticles

    Science.gov (United States)

    Moreau, J.W.; Weber, P.K.; Martin, M.C.; Gilbert, B.; Hutcheon, I.D.; Banfield, J.F.

    2007-01-01

    High-spatial-resolution secondary ion microprobe spectrometry, synchrotron radiation-based Fourier-transform infrared spectroscopy, and polyacrylamide gel analysis demonstrated the intimate association of proteins with spheroidal aggregates of biogenic zinc sulfide nanocrystals, an example of extracellular biomineralization. Experiments involving synthetic zinc sulfide nanoparticles and representative amino acids indicated a driving role for cysteine in rapid nanoparticle aggregation. These findings suggest that microbially derived extracellular proteins can limit the dispersal of nanoparticulate metal-bearing phases, such as the mineral products of bioremediation, that may otherwise be transported away from their source by subsurface fluid flow.

  20. Extracellular Proteins Limit the Dispersal of BiogenicNanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, John W.; Weber, Peter K.; Martin, Michael C.; Gilbert,Benjamin; Hutcheon, Ian D.; Banfield, Jillian F.

    2007-04-27

    High spatial-resolution secondaryion microprobespectrometry, synchrotron radiation Fourier-transform infraredspectroscopy and polyacrylamide gel analysis demonstrate the intimateassociation of proteins with spheroidal aggregates of biogenic zincsulfide nanocrystals, an example of extracellular biomineralization.Experiments involving synthetic ZnS nanoparticles and representativeamino acids indicate a driving role for cysteine in rapid nanoparticleaggregation. These findings suggest that microbially-derivedextracellular proteins can limit dispersal of nanoparticulatemetal-bearing phases, such as the mineral products of bioremediation,that may otherwise be transported away from their source by subsurfacefluid flow.

  1. The contribution of tephra constituents during biogenic silica determination: implications for soil and paleoecological studies

    Directory of Open Access Journals (Sweden)

    W. Clymans

    2015-02-01

    Full Text Available Biogenic silica (BSi is used as a proxy by soil scientists to identify biological effects on the Si cycle and by paleoecologists to study environmental changes. Alkaline extractions are typically used to measure BSi in both terrestrial and aquatic environments. The dissolution properties of volcanic glass in tephra deposits and their nano-crystalline weathering products are hypothesized to overlap those of BSi, however, data to support this behavior are lacking. The understanding that the Si-bearing fractions that dissolve in alkaline media (SiAlk do not necessarily correspond to BSi, question the applicability of BSi as a proxy. Here, analysis of 15 samples reported as tephra-containing allows us to reject the hypothesis that tephra constituents produce an identical dissolution signal to that of BSi during alkaline extraction. We found that dissolution of volcanic glass shards is incomplete during alkaline dissolution. Simultaneous measurement of Al and Si used here during alkaline dissolution provides an important parameter to enable us to separate glass shard dissolution from dissolution of BSi and other Si-bearing fractions. The contribution from volcanic glass shard (between 0.2–4 wt.% SiO2, the main constituent of distal tephra, during alkaline dissolution can be substantial depending on the total SiAlk. Hence, soils and lake sediments with low BSi concentrations are highly sensitive to the additional dissolution from tephra constituents and its weathering products. We advise evaluation of the potential for volcanic or other non-biogenic contributions for all types of studies using BSi as an environmental proxy.

  2. Modeling organic aerosols during MILAGRO: importance of biogenic secondary organic aerosols

    Directory of Open Access Journals (Sweden)

    A. Hodzic

    2009-09-01

    Full Text Available The meso-scale chemistry-transport model CHIMERE is used to assess our understanding of major sources and formation processes leading to a fairly large amount of organic aerosols – OA, including primary OA (POA and secondary OA (SOA – observed in Mexico City during the MILAGRO field project (March 2006. Chemical analyses of submicron aerosols from aerosol mass spectrometers (AMS indicate that organic particles found in the Mexico City basin contain a large fraction of oxygenated organic species (OOA which have strong correspondence with SOA, and that their production actively continues downwind of the city. The SOA formation is modeled here by the one-step oxidation of anthropogenic (i.e. aromatics, alkanes, biogenic (i.e. monoterpenes and isoprene, and biomass-burning SOA precursors and their partitioning into both organic and aqueous phases. Conservative assumptions are made for uncertain parameters to maximize the amount of SOA produced by the model. The near-surface model evaluation shows that predicted OA correlates reasonably well with measurements during the campaign, however it remains a factor of 2 lower than the measured total OA. Fairly good agreement is found between predicted and observed POA within the city suggesting that anthropogenic and biomass burning emissions are reasonably captured. Consistent with previous studies in Mexico City, large discrepancies are encountered for SOA, with a factor of 2–10 model underestimate. When only anthropogenic SOA precursors were considered, the model was able to reproduce within a factor of two the sharp increase in OOA concentrations during the late morning at both urban and near-urban locations but the discrepancy increases rapidly later in the day, consistent with previous results, and is especially obvious when the column-integrated SOA mass is considered instead of the surface concentration. The increase in the missing SOA mass in the afternoon coincides with the sharp drop in POA

  3. Comparative study of biogenic and abiotic iron-containing materials

    Science.gov (United States)

    Cherkezova-Zheleva, Z.; Shopska, M.; Paneva, D.; Kovacheva, D.; Kadinov, G.; Mitov, I.

    2016-12-01

    Series of iron-based biogenic materials prepared by cultivation of Leptothrix group of bacteria in different feeding media ( Sphaerotilus-Leptothrix group of bacteria isolation medium, Adler, Lieske and silicon-iron-glucose-peptone) were studied. Control samples were obtained in the same conditions and procedures but the nutrition media were not infected with bacteria, i.e. they were sterile. Room and low temperature Mössbauer spectroscopy, powder X-ray diffraction (XRD), and infrared spectroscopy (IRS) were used to reveal the composition and physicochemical properties of biomass and respective control samples. Comparative analysis showed differences in their composition and dispersity of present phases. Sample composition included different ratio of nanodimensional iron oxyhydroxide and oxide phases. Relaxation phenomena such as superparamagnetism or collective magnetic excitation behaviour were registered for some of them. The experimental data showed that the biogenic materials were enriched in oxyhydroxides of high dispersion. Catalytic behaviour of a selected biomass and abiotic material were studied in the reaction of CO oxidation. In situ diffuse-reflectance (DR) IRS was used to monitor the phase transformations in the biomass and CO conversion.

  4. Plio-Pleistocene Biogenic Opal Deposition in the Southern Ocean

    Science.gov (United States)

    Kuhn, G.; Gersonde, R.

    2002-12-01

    About 2/3 of the annual supply of silicic acid to the World Ocean is buried in the Southern Ocean as biogenic silica (BSi), formed by diatoms and radiolaria in surface waters and exported to the seafloor. Main BSi accumulation occurs in an area between the sea ice edge and the Polar Front Zone and seems to be steered by a complex interaction of biological and physical parameters governing the modern Southern Ocean ecosystem. Sediment cores recovered during Ocean Drilling Program Leg 177 and expeditions with RV POLARSTERN reveal the history of the opal deposition in the Atlantic and Pacific sector of the Southern Ocean during the Pliocene and the Pleistocene. This period is characterized by distinct changes and variability in global climate and ocean circulation that can be related to the spatial-temporal distribution of BSi deposition on long and short time scales. Changes in ocean circulation, water mass structure, sea ice and climatic variability that impact the distribution of silicic acid and the development of coarsly silicified diatoms (e.g. Actinocyclus ingens, Thalassiosira antarctica, Fragilariopsis kerguelensis), presenting the major carriers of biogenic opal, control past BSi deposition in the Southern Ocean. Major deposition in the area of the modern Southern Ocean opal belt starts at the Plio/Pleistocene transition. Such strong export of BSi and related organic carbon might have reinforced the trend of global cooling observed since the Mid-Pliocene climate optimum.

  5. Manganese carbonates as possible biogenic relics in Archean settings

    Science.gov (United States)

    Rincón-Tomás, Blanca; Khonsari, Bahar; Mühlen, Dominik; Wickbold, Christian; Schäfer, Nadine; Hause-Reitner, Dorothea; Hoppert, Michael; Reitner, Joachim

    2016-07-01

    Carbonate minerals such as dolomite, kutnahorite or rhodochrosite are frequently, but not exclusively generated by microbial processes. In recent anoxic sediments, Mn(II)carbonate minerals (e.g. rhodochrosite, kutnahorite) derive mainly from the reduction of Mn(IV) compounds by anaerobic respiration. The formation of huge manganese-rich (carbonate) deposits requires effective manganese redox cycling in an oxygenated atmosphere. However, putative anaerobic pathways such as microbial nitrate-dependent manganese oxidation, anoxygenic photosynthesis and oxidation in ultraviolet light may facilitate manganese cycling even in an early Archean environment, without the availability of oxygen. In addition, manganese carbonates precipitate by microbially induced processes without change of the oxidation state, e.g. by pH shift. Hence, there are several ways how these minerals could have been formed biogenically and deposited in Precambrian sediments. We will summarize microbially induced manganese carbonate deposition in the presence and absence of atmospheric oxygen and we will make some considerations about the biogenic deposition of manganese carbonates in early Archean settings.

  6. 78 FR 50135 - Soil Biogenics Ltd., File No. 500-1; Order of Suspension of Trading

    Science.gov (United States)

    2013-08-16

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Soil Biogenics Ltd., File No. 500-1; Order of Suspension of Trading August 14, 2013. It appears to... concerning the securities of Soil Biogenics Ltd. because it has not filed ] any periodic reports since...

  7. Methylotrophic methanogenesis governs the biogenic coal bed methane formation in Eastern Ordos Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Liu, Ruyin; Zhang, Hongxun; Zhong, Qiding; Xiong, Zhenghe

    2012-12-01

    To identify themethanogenic pathways present in a deep coal bed methane (CBM) reservoir associated with Eastern Ordos Basin in China, a series of geochemical and microbiological studies was performed using gas and water samples produced from the Liulin CBM reservoir. The composition and stable isotopic ratios of CBM implied a mixed biogenic and thermogenic origin of the methane. Archaeal 16S rRNA gene analysis revealed the dominance of the methylotrophic methanogen Methanolobus in the water produced. The high potential of methane production by methylotrophic methanogens was found in the enrichments using the water samples amended with methanol and incubated at 25 and 35 °C. Methylotrophic methanogens were the dominant archaea in both enrichments as shown by polymerase chain reaction (PCR)–denaturing gradient gel electrophoresis (DGGE). Bacterial 16S rRNA gene analysis revealed that fermentative, sulfate-reducing, and nitrate-reducing bacteria inhabiting the water produced were a factor in coal biodegradation to fuel methanogens. These results suggested that past and ongoing biodegradation of coal by methylotrophic methanogens and syntrophic bacteria, as well as thermogenic CBM production, contributed to the Liulin CBM reserves associated with the Eastern Ordos Basin.

  8. Carbon and hydrogen isotopic composition and generation pathway of biogenic gas in China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ping; WANG Xiaofeng; XU Yin; SHI Baoguang; XU Yongchang

    2009-01-01

    The carbon and hydrogen isotopic composition of biogenic gas is of great importance for the study of its generation pathway and reservoiring characteristics. In this paper, the formation pathways and reservoiring characteristics of biogenic gas reservoirs in China are described in terms of the carbon and hydrogen isotopic compositions of 31 gas samples from 10 biogenic gas reservoirs. The study shows that the hydrogen isotopic compositions of these biogenic gas reservoirs can be divided into three intervals:δDCH4>-200‰,-250‰<δDCH4<-200‰ and δDCH4<-250‰. The forerunners believed that the main generation pathway of biogenic gas under the condition of continental fresh water is acetic fermentation. Our research results showed that the generation pathway of biogenic gas under the condition of marine facies is typical CO2- reduction, the biogenic gas has heavy hydrogen isotopic composition: its δDCH4 values are higher than -200‰; that the biogenic gas under the condition of continental facies also was generated by the same way, but its hydrogen isotopic composition is lighter than that of biogenetic gas generated under typical marine facies condition: -250‰<δDCH4<-200‰, the δDCH4 values may be related to the salinity of the water medium in ancient lakes. From the relevant data of the Qaidam Basin, it can be seen that the hydrogen isotopic composition of biogenic methane has the same variation trend with increasing salinity of water medium. There are biogenic gas reservoirs formed in transitional regions under the condition of continental facies. These gas reservoirs resulted from both CO2- reduction and acetic fermentation, the formation of which may be related to the non-variant salinity of ancient water medium and the relatively high geothermal gradient, as is the case encountered in the Baoshan Basin. The biogenic gas generating in these regions has light hydrogen isotopic composition: δDCH4<-250‰, and relatively heavy carbon isotopic

  9. Fluxes of Primary and Secondary Biogenic Volatile Organic Compounds (BVOC) During the BEWA Field Experiments

    Science.gov (United States)

    Steinbrecher, R.; Rappenglück, B.; Steigner, D.; Hansel, A.; Graus, M.; Lindinger, C.

    2003-12-01

    and biogenic VOCs. However, they may also be emitted directly. Growing evidence shows that beside anthropogenic significant biogenic sources exist for both compounds. The results of the BEWA campaign reveal only a poor correlation between acetaldehyde and acetone (r2=0.02) indicating different origins of both species. The observations show that acetone deposition prevails suggesting that biogenic sources of acetone play a minor role, at least at this site. Acetaldehyde fluxes usually better agree with isoprene fluxes (r2=0.55). However, they correlate best with MVK+MAC fluxes (r2=0.81). This is an indication that acetaldehyde is primarily produced in photochemical degradation processes of VOC. Methanol canopy fluxes reached 22 nmol m-2 s-1 and daytime methanol mixing ratios were up to 15 ppbv and were comparable with previously reported values. The methanol mixing ratios are consistent with its relatively long atmospheric life time of approximately 16 days making advection an important issue. However, twig enclosure measurements during the summer 2002 intensive field experiment at the Waldstein site did not reveal significant direct methanol emissions.

  10. Formation of anthropogenic secondary organic aerosol (SOA and its influence on biogenic SOA properties

    Directory of Open Access Journals (Sweden)

    E. U. Emanuelsson

    2013-03-01

    Full Text Available Secondary organic aerosol (SOA formation from mixed anthropogenic and biogenic precursors has been studied exposing reaction mixtures to natural sunlight in the SAPHIR chamber in Jülich, Germany. In this study aromatic compounds served as examples of anthropogenic volatile organic compound (VOC and a mixture of α-pinene and limonene as an example for biogenic VOC. Several experiments with exclusively aromatic precursors were performed to establish a relationship between yield and organic aerosol mass loading for the atmospheric relevant range of aerosol loads of 0.01 to 10 μg m−3. The yields (0.5 to 9% were comparable to previous data and further used for the detailed evaluation of the mixed biogenic and anthropogenic experiments. For the mixed experiments a number of different oxidation schemes were addressed. The reactivity, the sequence of addition, and the amount of the precursors influenced the SOA properties. Monoterpene oxidation products, including carboxylic acids and dimer esters were identified in the aged aerosol at levels comparable to ambient air. OH radicals were measured by Laser Induced Fluorescence, which allowed for establishing relations of aerosol properties and composition to the experimental OH dose. Furthermore, the OH measurements in combination with the derived yields for aromatic SOA enabled application of a simplified model to calculate the chemical turnover of the aromatic precursor and corresponding anthropogenic contribution to the mixed aerosol. The estimated anthropogenic contributions were ranging from small (≈8% up to significant fraction (>50% providing a suitable range to study the effect of aerosol composition on the aerosol volatility (volume fraction remaining (VFR at 343 K: 0.86–0.94. The aromatic aerosol had higher oxygen to carbon ratio O/C and was less volatile than the biogenic fraction. However, in order to produce significant amount of aromatic SOA the reaction mixtures needed a higher

  11. An evaluation of pretreatment agents for the stimulation of secondary biogenic coalbed natural gas

    Science.gov (United States)

    Huang, Zaixing

    permanganate treated samples, which had a much lower TOC (5%), were more promising in terms of biological conversion potential. The biometer assay data indicated that up to 1.1% of the coal carbon was mineralized to carbon dioxide (CO2) within a period of two weeks. On this basis, permanganate treated samples were utilized in subsequent experiments to evaluate potential biogenic methane generation. For the permanganate treated samples, 5.4% of the coal carbon was solubilized/depolymerized, and 3.2% of the soluble carbon was converted to methane (CH4). The methane was rapidly generated and peaked at 40-days with a cumulative amount of 93.4 mumol/g coal (73.9 standard cubic feet (Scf)/ton coal equivalent using linear extrapolation). This compares very favorably to the 22-74 Scf/ton said to exist within the PBR coalbeds prior to resource exploitation. Our data also showed that a small fraction, 143 mumol/g coal, of the soluble carbon which was designated as the volatile fraction (i.e., the purgeable fraction removable by sparging with N2 gas) is essential to the generation of biogenic methane from coal derived constituents. Subsequent studies evaluating the influence of the chemical pretreatment agents (HNO3, NaOH, catalyzed H 2O2, KMnO4) on the subsequent enzymatic conversion of subbituminous coal using a fungal manganese peroxidase (MnP) produced by the agaric white-rot fungus Bjerkandera adusta have shown that chemical pretreatments can also enhance the coal solubilization performance of MnP.

  12. Formation of anthropogenic secondary organic aerosol (SOA) and its influence on biogenic SOA properties

    Science.gov (United States)

    Emanuelsson, E. U.; Hallquist, M.; Kristensen, K.; Glasius, M.; Bohn, B.; Fuchs, H.; Kammer, B.; Kiendler-Scharr, A.; Nehr, S.; Rubach, F.; Tillmann, R.; Wahner, A.; Wu, H.-C.; Mentel, Th. F.

    2013-03-01

    Secondary organic aerosol (SOA) formation from mixed anthropogenic and biogenic precursors has been studied exposing reaction mixtures to natural sunlight in the SAPHIR chamber in Jülich, Germany. In this study aromatic compounds served as examples of anthropogenic volatile organic compound (VOC) and a mixture of α-pinene and limonene as an example for biogenic VOC. Several experiments with exclusively aromatic precursors were performed to establish a relationship between yield and organic aerosol mass loading for the atmospheric relevant range of aerosol loads of 0.01 to 10 μg m-3. The yields (0.5 to 9%) were comparable to previous data and further used for the detailed evaluation of the mixed biogenic and anthropogenic experiments. For the mixed experiments a number of different oxidation schemes were addressed. The reactivity, the sequence of addition, and the amount of the precursors influenced the SOA properties. Monoterpene oxidation products, including carboxylic acids and dimer esters were identified in the aged aerosol at levels comparable to ambient air. OH radicals were measured by Laser Induced Fluorescence, which allowed for establishing relations of aerosol properties and composition to the experimental OH dose. Furthermore, the OH measurements in combination with the derived yields for aromatic SOA enabled application of a simplified model to calculate the chemical turnover of the aromatic precursor and corresponding anthropogenic contribution to the mixed aerosol. The estimated anthropogenic contributions were ranging from small (≈8%) up to significant fraction (>50%) providing a suitable range to study the effect of aerosol composition on the aerosol volatility (volume fraction remaining (VFR) at 343 K: 0.86-0.94). The aromatic aerosol had higher oxygen to carbon ratio O/C and was less volatile than the biogenic fraction. However, in order to produce significant amount of aromatic SOA the reaction mixtures needed a higher OH dose that also

  13. Effect of autochthonous starter cultures on the biogenic amine content of ewe's milk cheese throughout ripening.

    Science.gov (United States)

    Renes, E; Diezhandino, I; Fernández, D; Ferrazza, R E; Tornadijo, M E; Fresno, J M

    2014-12-01

    Cheese is among the most commonly implicated foods associated with biogenic amines poisoning. The aim of this study was to evaluate the effects of the type of autochthonous starter culture and ripening time on the concentration of biogenic amines (histamine, tyramine, putrescine, cadaverine, tryptamine, β-phenylethylamine, spermine and spermidine) in cheeses made from pasteurized ewe's milk. 4 cheese batches were made, in duplicate, and ripened for 7 months. The biogenic amines of 40 cheeses were analysed by high performance liquid chromatography. The predominant biogenic amines determined at the end of the ripening time were phenylethylamine, spermine and tryptamine. Together, these accounted for 81% of the total of biogenic amines studied. The type of starter culture used to make the ewe's cheese had a significant effect (p culture made up entirely of Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris or of the same in combination with Lactobacillus plantarum.

  14. Influence of pH, competing ions, and salinity on the sorption of strontium and cobalt onto biogenic hydroxyapatite

    Science.gov (United States)

    Handley-Sidhu, Stephanie; Mullan, Thomas K.; Grail, Quentin; Albadarneh, Malek; Ohnuki, Toshihiko; Macaskie, Lynne E.

    2016-03-01

    Anthropogenic radionuclides contaminate a range of environments as a result of nuclear activities, for example, leakage from waste storage tanks/ponds (e.g. Hanford, USA or Sellafield sites, UK) or as a result of large scale nuclear accidents (e.g. Chernobyl, Ukraine or Fukushima, Japan). One of the most widely applied remediation techniques for contaminated waters is the use of sorbent materials (e.g. zeolites and apatites). However, a key problem at nuclear contaminated sites is the remediation of radionuclides from complex chemical environments. In this study, biogenic hydroxyapatite (BHAP) produced by Serratia sp. bacteria was investigated for its potential to remediate surrogate radionuclides (Sr2+ and Co2+) from environmentally relevant waters by varying pH, salinity and the type and concentration of cations present. The sorption capacity of the BHAP for both Sr2+ and Co2+ was higher than for a synthetically produced hydroxyapatite (HAP) in the solutions tested. BHAP also compared favorably against a natural zeolite (as used in industrial decontamination) for Sr2+ and Co2+ uptake from saline waters. Results confirm that hydroxyapatite minerals of high surface area and amorphous calcium phosphate content, typical for biogenic sources, are suitable restoration or reactive barrier materials for the remediation of complex contaminated environments or wastewaters.

  15. Production of biogenic amines by lactic acid bacteria and enterobacteria isolated from fresh pork sausages packaged in different atmospheres and kept under refrigeration.

    Science.gov (United States)

    Curiel, J A; Ruiz-Capillas, C; de Las Rivas, B; Carrascosa, A V; Jiménez-Colmenero, F; Muñoz, R

    2011-07-01

    The occurrence of in vitro amino acid activity in bacterial strains associated with fresh pork sausages packaged in different atmospheres and kept in refrigeration was studied. The presence of biogenic amines in decarboxylase broth was confirmed by ion-exchange chromatography and by the presence of the corresponding decarboxylase genes by PCR. From the 93 lactic acid bacteria and 100 enterobacteria strains analysed, the decarboxylase medium underestimates the number of biogenic amine-producer strains. 28% of the lactic acid bacteria produced tyramine and presented the tdc gene. All the tyramine-producer strains were molecularly identified as Carnobacterium divergens. Differences on the relative abundance of C. divergens were observed among the different packaging atmospheres assayed. After 28 days of storage, the presence of argon seems to inhibit C. divergens growth, while packing under vacuum seems to favour it. Among enterobacteria, putrescine was the amine more frequently produced (87%), followed by cadaverine (85%); agmatine and tyramine were only produced by 13 and 1%, respectively, of the strains analysed. Packing under vacuum or in an atmosphere containing nitrogen seems to inhibit the growth of enterobacteria which produce simultaneously putrescine, cadaverine, and agmatine. Contrarily, over-wrapping or packing in an atmosphere containing argon seems to favour the growth of agmatine producer-enterobacteria. The production of putrescine and cadaverine was associated with the presence of the corresponding amino acid decarboxylase genes. The biogenic amine-producer strains were included in a wide range of enterobacterial species, including Kluyvera intermedia, Enterobacter aerogenes, Yersinia kristensenii, Serratia grimesii, Serratia ficaria, Yersinia rodhei, Providencia vermicola and Obesumbacterium proteus.

  16. Biogenic hydrogen production from organic raw materials and residues; Biogene Wasserstofferzeugung aus organischen Roh- und Reststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.; Rechtenbach, D.; Stegmann, R. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Inst. fuer AbfallRessourcenWirtschaft

    2007-02-15

    Hydrogen (H{sub 2}) is considered as an energy source for the future. Laboratory scale thermophilic fermentation tests were carried out in three different test systems (500 ml Sensomat system, 6 l anaerobic test system (ATS) and a 30 l continuously stirred tank reactor CSTR). Hydrogen was produced from glucose and agricultural products as substrates in batch and discontinuous tests at 60 C. The inoculum consisted of heat-treated digested sewage sludge. The best specific hydrogen production of 280 Nml H{sub 2}/g VSS was achieved with glucose at a pH 5.5 in batch operation in the CSTR. Corn starch produced 211 Nml H{sub 2}/g VSS and potato starch 123 Nml H{sub 2}/g VSS. The agricultural products sugar beet, fodder beet, potato, turnip, corn and bio-waste potato peel showed good potential for biological hydrogen production with conversion yields between 24 - 60%. In the discontinuous test system, hydrogen production rates of between 0.4 Nl/(l{sub R}.d) and 1.3 Nl/(l{sub R}.d) were produced, corresponding to yields of between 83 to 445 Nml H{sub 2}/g VSS. (orig.)

  17. Biogenic CO2 fluxes, changes in surface albedo and biodiversity impacts from establishment of a miscanthus plantation.

    Science.gov (United States)

    Jørgensen, Susanne V; Cherubini, Francesco; Michelsen, Ottar

    2014-12-15

    Depletion in oil resources and environmental concern related to the use of fossil fuels has increased the interest in using second generation biomass as alternative feedstock for fuels and materials. However, the land use and land use change for producing second generation (2G) biomass impacts the environment in various ways, of which not all are usually considered in life cycle assessment. This study assesses the biogenic CO2 fluxes, surface albedo changes and biodiversity impacts for 100 years after changing land use from forest or fallow land to miscanthus plantation in Wisconsin, US. Climate change impacts are addressed in terms of effective forcing, a mid-point indicator which can be used to compare impacts from biogenic CO2 fluxes and albedo changes. Biodiversity impacts are assessed through elaboration on two different existing approaches, to express the change in biodiversity impact from one human influenced state to another. Concerning the impacts from biogenic CO2 fluxes, in the case of conversion from a forest to a miscanthus plantation (case A) there is a contribution to global warming, whereas when a fallow land is converted (case B), there is a climate cooling. When the effects from albedo changes are included, both scenarios show a net cooling impact, which is more pronounced in case B. Both cases reduce biodiversity in the area where the miscanthus plantation is established, though most in case A. The results illustrate the relevance of these issues when considering environmental impacts of land use and land use change. The apparent trade-offs in terms of environmental impacts further highlight the importance of including these aspects in LCA of land use and land use changes, in order to enable informed decision making.

  18. Occurrence of gigantic biogenic magnetite during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Schumann, D.; Raub, T. D.; Kopp, R. E.; Guerquin-Kern, J. L.; Wu, T. D.; Rouiller, I.; Smirnov, A. V.; Sears, S. K.; Lücken, U.; Tikoo, S. M.; Hesse, R.; Kirschvink, J. L.; Vali, H.

    2009-04-01

    The Paleocene-Eocene Thermal Maximum (PETM) is one of the most severe climatic events of the Cenozoic Era. A massive injection of light carbon into the oceans and atmosphere over a few thousand of years triggered drastic perturbation of Earth's climate resulting in abrupt global warming of ~5-9oC [Sluijs et al., 2007] that persisted for ~180,000 years. This episode is marked by the diversification and radiation of terrestrial plants and mammals while in the marine realm numerous deep-sea benthic foraminifera species disappeared and new forms evolved. Sediments deposited during the PETM are clay-rich and contain distinct evidence of these climatic changes. Kopp et al., (2007) and Lippert & Zachos (2007) report an extraordinary magnetofossil ‘Lagerstätte' in lowermost Eocene kaolinite-rich clay sediments deposited at subtropical paleolatitude in the Atlantic Coastal Plain of New Jersey, USA. Magnetofossils are magnetic particles produced most abundantly by magnetotactic bacteria. Kopp et al. (2007) and Lippert & Zachos (2007) used ferromagnetic resonance (FMR) spectroscopy, other rock magnetic methods, and transmission electron microscopy (TEM) of magnetic separates to characterize sediments from boreholes at Ancora (ODP Leg 174AX) and Wilson Lake, NJ, respectively. These sediments contain abundant ~40- to 300-nm cuboidal, elongate-prismatic and bullet-shaped magnetofossils, sometimes arranged in short chains, resembling crystals in living magnetotactic bacteria. Despite the scarcity of intact magnetofossil chains, the asymmetry ratios of the FMR spectra reflects a profusion of elongate single domain (SD) crystals and/or chains. Here we address both conundrums by reporting the discovery from these same sediments of exceptionally large and novel biogenic magnetite crystals unlike any previously reported from living organisms or from sediments. Aside from abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite

  19. Biogenic emission measurement and inventories determination of biogenic emissions in the eastern United States and Texas and comparison with biogenic emission inventories

    Science.gov (United States)

    Warneke, C.; de Gouw, J. A.; Del Negro, L.; Brioude, J.; McKeen, S.; Stark, H.; Kuster, W. C.; Goldan, P. D.; Trainer, M.; Fehsenfeld, F. C.; Wiedinmyer, C.; Guenther, A. B.; Hansel, A.; Wisthaler, A.; Atlas, E.; Holloway, J. S.; Ryerson, T. B.; Peischl, J.; Huey, L. G.; Hanks, A. T. Case

    2010-04-01

    During the NOAA Southern Oxidant Study 1999 (SOS1999), Texas Air Quality Study 2000 (TexAQS2000), International Consortium for Atmospheric Research on Transport and Transformation (ICARTT2004), and Texas Air Quality Study 2006 (TexAQS2006) campaigns, airborne measurements of isoprene and monoterpenes were made in the eastern United States and in Texas, and the results are used to evaluate the biogenic emission inventories BEIS3.12, BEIS3.13, MEGAN2, and WM2001. Two methods are used for the evaluation. First, the emissions are directly estimated from the ambient isoprene and monoterpene measurements assuming a well-mixed boundary layer and are compared with the emissions from the inventories extracted along the flight tracks. Second, BEIS3.12 is incorporated into the detailed transport model FLEXPART, which allows the isoprene and monoterpene mixing ratios to be calculated and compared to the measurements. The overall agreement for all inventories is within a factor of 2 and the two methods give consistent results. MEGAN2 is in most cases higher, and BEIS3.12 and BEIS3.13 lower than the emissions determined from the measurements. Regions with clear discrepancies are identified. For example, an isoprene hot spot to the northwest of Houston, Texas, was expected from BEIS3 but not observed in the measurements. Interannual differences in emissions of about a factor of 2 were observed in Texas between 2000 and 2006.

  20. Rates of microbial sulfate reduction control the sizes of biogenic iron sulfide aggregates

    Science.gov (United States)

    Jin, Q.

    2005-12-01

    Sulfide minerals occur widely in freshwater and marine sediments as byproducts of microbial sulfate reduction and as end products of heavy metal bioremediation. They form when metals in the environments combine with sulfide produced from the metabolism of sulfate reducing bacteria. We used chemostat bioreactors to study sizes and crystal structures of iron sulfide (FeS) minerals produced by Desulfovibrio vulgaris, D. desulfuricans strain G20, and subspecies desulfuricans. FeS nanoparticles and their aggregates are characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS). FeS nanoparticles produced by sulfate reducing bacteria are extremely small, usually less than around 10 nm in diameter. Nanoparticles do not occur as individual nanoparticles, but as aggregates. The sizes of FeS aggregates are affected by sulfate reduction rates, Fe(II) concentration, pH, ionic strength, organic matter concentration, bacterial species, etc. Aggregate size ranges from about 500 nm at very large sulfate reduction rates to about 1,500 nm at very small rates. Variations in Fe(II) concentration also lead to a difference up to 500 nm in FeS aggregate size. Different bacterial species produce nanoparticle aggregates of different sizes under similar growth conditions. For example, D. vulgaris produces FeS aggregates with sizes 500 nm smaller than those by strain G20. The inverse relationship between FeS aggregate sizes and sulfate reduction rates is important in evaluating metal bioremediation strategies. Previous approaches have focused on stimulating microbial activities in natural environments. However, our experimental results suggest that increasing metabolic rates may decrease the aggregate size, increasing the mobility of colloidal aggregates. Therefore, the balance between microbial activities and sizes of biogenic aggregates may be an important consideration in the design and

  1. Organic nitrate aerosol formation via NO3 + biogenic volatile organic compounds in the southeastern United States

    Science.gov (United States)

    Ayres, B. R.; Allen, H. M.; Draper, D. C.; Brown, S. S.; Wild, R. J.; Jimenez, J. L.; Day, D. A.; Campuzano-Jost, P.; Hu, W.; de Gouw, J.; Koss, A.; Cohen, R. C.; Duffey, K. C.; Romer, P.; Baumann, K.; Edgerton, E.; Takahama, S.; Thornton, J. A.; Lee, B. H.; Lopez-Hilfiker, F. D.; Mohr, C.; Wennberg, P. O.; Nguyen, T. B.; Teng, A.; Goldstein, A. H.; Olson, K.; Fry, J. L.

    2015-12-01

    Gas- and aerosol-phase measurements of oxidants, biogenic volatile organic compounds (BVOCs) and organic nitrates made during the Southern Oxidant and Aerosol Study (SOAS campaign, Summer 2013) in central Alabama show that a nitrate radical (NO3) reaction with monoterpenes leads to significant secondary aerosol formation. Cumulative losses of NO3 to terpenes are correlated with increase in gas- and aerosol-organic nitrate concentrations made during the campaign. Correlation of NO3 radical consumption to organic nitrate aerosol formation as measured by aerosol mass spectrometry and thermal dissociation laser-induced fluorescence suggests a molar yield of aerosol-phase monoterpene nitrates of 23-44 %. Compounds observed via chemical ionization mass spectrometry (CIMS) are correlated to predicted nitrate loss to BVOCs and show C10H17NO5, likely a hydroperoxy nitrate, is a major nitrate-oxidized terpene product being incorporated into aerosols. The comparable isoprene product C5H9NO5 was observed to contribute less than 1 % of the total organic nitrate in the aerosol phase and correlations show that it is principally a gas-phase product from nitrate oxidation of isoprene. Organic nitrates comprise between 30 and 45 % of the NOy budget during SOAS. Inorganic nitrates were also monitored and showed that during incidents of increased coarse-mode mineral dust, HNO3 uptake produced nitrate aerosol mass loading at a rate comparable to that of organic nitrate produced via NO3 + BVOCs.

  2. Bacillus megaterium mediated mineralization of calcium carbonate as biogenic surface treatment of green building materials.

    Science.gov (United States)

    Dhami, Navdeep Kaur; Reddy, M Sudhakara; Mukherjee, Abhijit

    2013-12-01

    Microbially induced calcium carbonate precipitation is a biomineralization process that has various applications in remediation and restoration of range of building materials. In the present study, calcifying bacteria, Bacillus megaterium SS3 isolated from calcareous soil was applied as biosealant to enhance the durability of low energy, green building materials (soil-cement blocks). This bacterial isolate produced high amounts of urease, carbonic anhydrase, extra polymeric substances and biofilm. The calcium carbonate polymorphs produced by B. megaterium SS3 were analyzed by scanning electron microscopy, confocal laser scanning microscopy, X-ray diffraction and Fourier transmission infra red spectroscopy. These results suggested that calcite is the most predominant carbonate formed by this bacteria followed by vaterite. Application of B. megaterium SS3 as biogenic surface treatment led to 40 % decrease in water absorption, 31 % decrease in porosity and 18 % increase in compressive strength of low energy building materials. From the present investigation, it is clear that surface treatment of building materials by B. megaterium SS3 is very effective and eco friendly way of biodeposition of coherent carbonates that enhances the durability of building materials.

  3. Biogenic synthesis of gold and silver nanoparticles by seed plants.

    Science.gov (United States)

    Iyer, R Indira; Panda, Tapobrata

    2014-02-01

    Nanoparticles have an enormous range of biomedical and environmental applications and can be used for development of various nanodevices for diagnostics and drug delivery. Biogenic production of nanoparticles, that is of silver and gold, by seed plants, especially flowering plants, has evoked considerable interest in the last decade. Different organs of plants as well as callus cultures have been used for the production of these metal nanoparticles. It is possible to regulate the geometry of the nanoparticles by modifying the experimental parameters. In many cases the phytosynthesized gold and silver nanoparticles have been demonstrated to be potentially useful for treatment of various diseases. The production of gold and silver nanoparticles by diverse species of seed plants and their biological activity are discussed in this article.

  4. Development of biogenic VOC emission inventories for the boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, V.

    2008-07-01

    The volatile organic compounds (VOCs) emitted by vegetation, especially forests, can affect local and regional atmospheric photochemistry through their reactions with atmospheric oxidants. Their reaction products may also participate in the formation and growth of new particles which affect the radiation balance of the atmosphere, and thus climate, by scattering and absorbing shortwave and longwave radiation and by modifying the radiative properties, amount and lifetime of clouds. Globally, anthropogenic VOC emissions are far surpassed by the biogenic ones, making biogenic emission inventories an integral element in the development of efficient air quality and climate strategies. The inventories are typically constructed based on landcover information, measured emissions of different plants or vegetation types, and empirical dependencies of the emissions on environmental variables such as temperature and light. This thesis is focused on the VOC emissions from the boreal forest, the largest terrestrial biome with characteristic vegetation patterns and strong seasonality. The isoprene, monoterpene and sesquiterpene emissions of the most prevalent boreal tree species in Finland, Scots pine, have been measured and their seasonal variation and dependence on temperature and light have been studied. The measured emission data and other available observations of the emissions of the principal boreal trees have been used in a biogenic emission model developed for the boreal forests in Finland. The model utilizes satellite landcover information, Finnish forest classification and hourly meteorological data to calculate isoprene, monoterpene, sesquiterpene and other VOC emissions over the growing season. The principal compounds emitted by Scots pine are DELTA3-carene and alpha-pinene in the south boreal zone and alpha- and beta-pinene in the north boreal zone. The monoterpene emissions are dependent on temperature and have a clear seasonal cycle with high emissions in spring

  5. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...... dependent and the emissions will increase in a future warmer climate. The aims of this dissertation were to study BVOC emission rates and blends from arctic ecosystems and to reveal the effect of climate change on BVOC emissions from the Arctic. BVOC emissions were measured in ambient and modified...

  6. Constraining Anthropogenic and Biogenic Emissions Using Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Spencer, Kathleen M.

    Numerous gas-phase anthropogenic and biogenic compounds are emitted into the atmosphere. These gases undergo oxidation to form other gas-phase species and particulate matter. Whether directly or indirectly, primary pollutants, secondary gas-phase products, and particulate matter all pose health and environmental risks. In this work, ambient measurements conducted using chemical ionization mass spectrometry are used as a tool for investigating regional air quality. Ambient measurements of peroxynitric acid (HO2NO2) were conducted in Mexico City. A method of inferring the rate of ozone production, PO3, is developed based on observations of HO2NO 2, NO, and NO2. Comparison of this observationally based PO3 to a highly constrained photochemical box model indicates that regulations aimed at reducing ozone levels in Mexico City by reducing NOx concentrations may be effective at higher NO x levels than predicted using accepted photochemistry. Measurements of SO2 and particulate sulfate were conducted over the Los Angeles basin in 2008 and are compared to measurements made in 2002. A large decrease in SO2 concentration and a change in spatial distribution are observed. Nevertheless, only a modest reduction in sulfate concentration is observed at ground sites within the basin. Possible explanations for these trends are investigated. Two techniques, single and triple quadrupole chemical ionization mass spectrometry, were used to quantify ambient concentrations of biogenic oxidation products, hydroxyacetone and glycolaldehyde. The use of these techniques demonstrates the advantage of triple quadrupole mass spectrometry for separation of mass analogues, provided the collision-induced daughter ions are sufficiently distinct. Enhancement ratios of hydroxyacetone and glycolaldehyde in Californian biomass burning plumes are presented as are concentrations of these compounds at a rural ground site downwind of Sacramento.

  7. Biophysics of Magnetic Orientation: Radical Pairs, Biogenic Magnetite, or both?

    Science.gov (United States)

    Kirschvink, Joe

    2011-03-01

    Two major biophysical mechanisms for magnetoreception in terrestrial animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, have been the subject of experiment and debate for the past 30 years. The magnetite hypothesis has stood the test of time: biogenic magnetite is synthesized biochemically in Bacteria, Protists, and numerous Animal phyla, as well as in some plants. Chains of single-domain crystals have been detected by clean-lab based SQUID magnetometry in animal tissues in all major phyla, followed by high-resolution TEM in selected model organisms, as well as by electrophysiological studies demonstrating the role of the ophthalmic branch of the trigeminal nerve in the magnetoreceptive process. Pulse-remagnetization - configured to uniquely flip the polarity of single-domain ferromagnets - has dramatic effects on the behavior of many birds, honeybees, mole rats, turtles, and bats, to cite a growing list. Magnetite-containing cells in the vicinity of these neurons in fish are now the subject of intense study by our consortium. The existence of a specialized class of magnetite-containing magnetoreceptor cells in animal tissues is no longer controversial. In contrast, less success has been achieved in gaining experimental support across a range of taxa for the radical-pair hypothesis. Although this mechanism was proposed to explain an early observation that birds would not respond to complete inversion of the magnetic vector, many organisms (even some birds) do indeed respond to the field polarity. We also note that few, if any, of these critical experiments have been done using fully double-blind methods. This is joint work with: M. M. Walker (University of Auckland, New Zealand) and M. Winklhofer (LMU Munich, Germany).

  8. Understanding the contributions of anthropogenic and biogenic sources to CO enhancements and outflow observed over North America and the western Atlantic Ocean by TES and MOPITT

    Science.gov (United States)

    Choi, Yunsoo; Osterman, Gregory; Eldering, Annmarie; Wang, Yuhang; Edgerton, Eric

    2010-05-01

    We investigate the effects of anthropogenic and biogenic sources on tropospheric CO enhancements and outflow over North America and the Atlantic during July-August 2006, the 3rd warmest summer on record. The analysis is performed using the 3D Regional chEmical trAnsport Model (REAM), satellite data from TES on the Aura satellite, MOPITT on the Terra satellite and surface monitor data from the SEARCH network. The satellite measurements of CO provide insight into the location of regional CO enhancements along with the ability to resolve vertical features. Satellite and surface monitor data are used to compare with REAM, illustrating model's ability to reproduce observed CO concentrations. The REAM model used in this study features CO emissions reduced by 50% from the 1999 EPA NEI and biogenic VOC emissions scaled by EPA-observed isoprene concentrations (20% reduction). The REAM simulations show large variations in surface CO, lower tropospheric CO and column CO, which are also observed by the surface observations and satellite data. Over the US, during July-August 2006, the model estimates monthly CO production from anthropogenic sources (5.3 and 5.1 Tg CO) is generally larger than biogenic sources (4.3 and 3.5 Tg CO). However, the model shows that for very warm days, biogenic sources produce as much CO as anthropogenic sources, a result of increased biogenic production due to warmer temperatures. The satellite data show CO outflow occurs along the East Coast of the US and Canada in July and is more broadly distributed over the Atlantic in August. REAM results show the longitudinally exported CO enhancements from anthropogenic sources (3.3 and 3.9 Tg CO) are larger than biogenic sources (2.8 and 2.7 Tg CO) along the eastern boundary of REAM for July-August 2006. We show that when compared with the impacts of both sources on increasing tropospheric CO exports, the relative impacts in August are greater than in July because of preferable outflow transport.

  9. Operation of Marine Diesel Engines on Biogenic Fuels: Modification of Emissions and Resulting Climate Effects

    OpenAIRE

    Petzold, A.; P. Lauer; Fritsche, U.; Hasselbach, J.; Lichtenstern, M.; Schlager, H.; Fleischer, F.

    2011-01-01

    The modification of emissions of climate-sensitive exhaust compounds such as CO2, NOx, hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fue...

  10. Biogenic nanoparticles: copper, copper oxides, copper sulphides, complex copper nanostructures and their applications.

    Science.gov (United States)

    Rubilar, Olga; Rai, Mahendra; Tortella, Gonzalo; Diez, Maria Cristina; Seabra, Amedea B; Durán, Nelson

    2013-09-01

    Copper nanoparticles have been the focus of intensive study due to their potential applications in diverse fields including biomedicine, electronics, and optics. Copper-based nanostructured materials have been used in conductive films, lubrification, nanofluids, catalysis, and also as potent antimicrobial agent. The biogenic synthesis of metallic nanostructured nanoparticles is considered to be a green and eco-friendly technology since neither harmful chemicals nor high temperatures are involved in the process. The present review discusses the synthesis of copper nanostructured nanoparticles by bacteria, fungi, and plant extracts, showing that biogenic synthesis is an economically feasible, simple and non-polluting process. Applications for biogenic copper nanoparticles are also discussed.

  11. Impact of biogenic very short-lived bromine on the Antarctic ozone hole during the 21st century

    Science.gov (United States)

    Fernandez, Rafael P.; Kinnison, Douglas E.; Lamarque, Jean-Francois; Tilmes, Simone; Saiz-Lopez, Alfonso

    2017-02-01

    Active bromine released from the photochemical decomposition of biogenic very short-lived bromocarbons (VSLBr) enhances stratospheric ozone depletion. Based on a dual set of 1960-2100 coupled chemistry-climate simulations (i.e. with and without VSLBr), we show that the maximum Antarctic ozone hole depletion increases by up to 14 % when natural VSLBr are considered, which is in better agreement with ozone observations. The impact of the additional 5 pptv VSLBr on Antarctic ozone is most evident in the periphery of the ozone hole, producing an expansion of the ozone hole area of ˜ 5 million km2, which is equivalent in magnitude to the recently estimated Antarctic ozone healing due to the implementation of the Montreal Protocol. We find that the inclusion of VSLBr in CAM-Chem (Community Atmosphere Model with Chemistry, version 4.0) does not introduce a significant delay of the modelled ozone return date to 1980 October levels, but instead affects the depth and duration of the simulated ozone hole. Our analysis further shows that total bromine-catalysed ozone destruction in the lower stratosphere surpasses that of chlorine by the year 2070 and indicates that natural VSLBr chemistry would dominate Antarctic ozone seasonality before the end of the 21st century. This work suggests a large influence of biogenic bromine on the future Antarctic ozone layer.

  12. A review on biogenic synthesis of ZnO nanoparticles using plant extracts and microbes: A prospect towards green chemistry.

    Science.gov (United States)

    Ahmed, Shakeel; Annu; Chaudhry, Saif Ali; Ikram, Saiqa

    2017-01-01

    Nanotechnology is emerging as an important area of research with its tremendous applications in all fields of science, engineering, medicine, pharmacy, etc. It involves the materials and their applications having one dimension in the range of 1-100nm. Generally, various techniques are used for syntheses of nanoparticles (NPs) viz. laser ablation, chemical reduction, milling, sputtering, etc. These conventional techniques e.g. chemical reduction method, in which various hazardous chemicals are used for the synthesis of NPs later become liable for innumerable health risks due to their toxicity and endangering serious concerns for environment, while other approaches are expensive, need high energy for the synthesis of NPs. However, biogenic synthesis method to produce NPs is eco-friendly and free of chemical contaminants for biological applications where purity is of concerns. In biological method, different biological entities such as extract, enzymes or proteins of a natural product are used to reduce and stabilised formation of NPs. The nature of these biological entities also influence the structure, shape, size and morphology of synthesized NPs. In this review, biogenic synthesis of zinc oxide (ZnO) NPs, procedures of syntheses, mechanism of formation and their various applications have been discussed. Various entities such as proteins, enzymes, phytochemicals, etc. available in the natural reductants are responsible for synthesis of ZnO NPs.

  13. A contribution of hydrogenotrophic methanogenesis to the biogenic coal bed methane reserves of Southern Qinshui Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Thompson, Ian P; Zhang, Hongxun

    2014-11-01

    The activity of methanogens and related bacteria which inhabit the coal beds is essential for stimulating new biogenic coal bed methane (CBM) production from the coal matrix. In this study, the microbial community structure and methanogenesis were investigated in Southern Qinshui Basin in China, and the composition and stable isotopic ratios of CBM were also determined. Although geochemical analysis suggested a mainly thermogenic origin for CBM, the microbial community structure and activities strongly implied the presence of methanogens in situ. 454 pyrosequencing analysis combined with methyl coenzyme-M reductase (mcrA) gene clone library analysis revealed that the archaeal communities in the water samples from both coal seams were similar, with the dominance of hydrogenotrophic methanogen Methanobacterium. The activity and potential of these populations to produce methane were confirmed by the observation of methane production in enrichments supplemented with H2 + CO2 and formate, and the only archaea successfully propagated in the tested water samples was from the genus Methanobacterium. 454 pyrosequencing analysis also recovered the diverse bacterial communities in the water samples, which have the potential to play a role in the coal biodegradation fueling methanogens. These results suggest that the biogenic CBM was generated by coal degradation via the hydrogenotrophic methanogens and related bacteria, which also contribute to the huge CBM reserves in Southern Qinshui Basin, China.

  14. Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean

    Science.gov (United States)

    Vidya, P. J.; Prasanna Kumar, S.; Gauns, M.; Verenkar, A.; Unger, D.; Ramaswamy, V.

    2013-11-01

    Seasonal cycle of biogenic fluxes obtained from sediment trap at two locations 5°24' N, 86°46' E (southern Bay of Bengal trap; SBBT) and 3°34' N, 77°46' E (equatorial Indian Ocean trap; EIOT) within the equatorial Indian Ocean (EIO) were examined to understand the factors that control them. The sediment trap data at SBBT was collected for ten years from November 1987 while that at EIOT was for a one year period from January 1996. The characteristic of biogenic flux at SBBT was the strong seasonality with peak flux in August, while lack of seasonality characterised the flux at EIOT. The high chlorophyll biomass at the SBBT during the summer monsoon was supported by a combination of processes such as wind-mixing and advection, both of which supplied new nitrogen to the upper ocean. In contrast, the elevated chlorophyll at EIOT during summer monsoon was supported only by wind mixing. High cell counts of phytoplankton (> 5 μm) at SBBT dominated by diatoms suggest the operation of classical food web and high carbon export. On the contrary, dominance of pico-phytoplankton and one-and-a-half time higher magnitude of micro-zooplankton biomass along with 2-fold lesser meso-zooplankton at EIOT indicated the importance of microbial loop. The substantial decrease in the carbon export at EIOT indicated faster remineralization of photosynthetically produced organic matter.

  15. Microbially-Enhanced Coal Bed Methane: Strategies for Increased Biogenic Production

    Science.gov (United States)

    Davis, K.; Barhart, E. P.; Schweitzer, H. D.; Cunningham, A. B.; Gerlach, R.; Hiebert, R.; Fields, M. W.

    2014-12-01

    Coal is the largest fossil fuel resource in the United States. Most of this coal is deep in the subsurface making it costly and potentially dangerous to extract. However, in many of these deep coal seams, methane, the main component of natural gas, has been discovered and successfully harvested. Coal bed methane (CBM) currently accounts for approximately 7.5% of the natural gas produced in the U.S. Combustion of natural gas produces substantially less CO2 and toxic emissions (e.g. heavy metals) than combustion of coal or oil thereby making it a cleaner energy source. In the large coal seams of the Powder River Basin (PRB) in southeast Montana and northeast Wyoming, CBM is produced almost entirely by biogenic processes. The in situ conversion of coal to CBM by the native microbial community is of particular interest for present and future natural gas sources as it provides the potential to harvest energy from coal seams with lesser environmental impacts than mining and burning coal. Research at Montana State University has shown the potential for enhancing the subsurface microbial processes that produce CBM. Long-term batch enrichments have investigated the methane enhancement potential of yeast extract as well as algal and cyanobacterial biomass additions with increased methane production observed with all three additions when compared to no addition. Future work includes quantification of CBM enhancement and normalization of additions. This presentation addresses the options thus far investigated for increasing CBM production and the next steps for developing the enhanced in situ conversion of coal to CBM.

  16. A biogenic CO2 flux adjustment scheme for the mitigation of large-scale biases in global atmospheric CO2 analyses and forecasts

    Science.gov (United States)

    Agustí-Panareda, Anna; Massart, Sébastien; Chevallier, Frédéric; Balsamo, Gianpaolo; Boussetta, Souhail; Dutra, Emanuel; Beljaars, Anton

    2016-08-01

    Forecasting atmospheric CO2 daily at the global scale with a good accuracy like it is done for the weather is a challenging task. However, it is also one of the key areas of development to bridge the gaps between weather, air quality and climate models. The challenge stems from the fact that atmospheric CO2 is largely controlled by the CO2 fluxes at the surface, which are difficult to constrain with observations. In particular, the biogenic fluxes simulated by land surface models show skill in detecting synoptic and regional-scale disturbances up to sub-seasonal time-scales, but they are subject to large seasonal and annual budget errors at global scale, usually requiring a posteriori adjustment. This paper presents a scheme to diagnose and mitigate model errors associated with biogenic fluxes within an atmospheric CO2 forecasting system. The scheme is an adaptive scaling procedure referred to as a biogenic flux adjustment scheme (BFAS), and it can be applied automatically in real time throughout the forecast. The BFAS method generally improves the continental budget of CO2 fluxes in the model by combining information from three sources: (1) retrospective fluxes estimated by a global flux inversion system, (2) land-use information, (3) simulated fluxes from the model. The method is shown to produce enhanced skill in the daily CO2 10-day forecasts without requiring continuous manual intervention. Therefore, it is particularly suitable for near-real-time CO2 analysis and forecasting systems.

  17. Effect of spermidine and its metabolites on the activity of pea seedlings diamine oxidase and the problems of biosensing of biogenic amines with this enzyme.

    Science.gov (United States)

    Kivirand, K; Sõmerik, H; Oldekop, M-L; Rebane, R; Rinken, T

    2016-01-01

    Spermidine is one of the several biogenic amines, produced during the microbial decarboxylation of proteins. Individual biogenic amines in the formed mixtures are frequently analyzed with oxygen sensor based biosensors, as their content serves as a good biomarker for the determination of food quality. In these biosensors, diamine oxidase from pea seedlings (PSAO), catalyzing the oxidation of various biogenic amines by dissolved oxygen is commonly used for the bio-recognition of amines. However, in the presence of spermidine and/or its metabolite 1,3-diaminopropane, the activity of PSAO and the sensitivity of PSAO-based biosensors decrease due to inhibition. The inhibition constant of soluble spermidine, acting as an inhibiting substrate toward PSAO, was found to be (40±15) mM in freshly prepared solution and (0.28±0.05) mM in solution, incubated 30 days at room temperature. The inhibition constant of 1,3-diaminopropane, acting as a competitive inhibitor, was (0.43±0.12) mM as determined through the oxidation reaction of cadaverine. The metabolic half-life of soluble spermidine was 7 days at room temperature and 186 days at 4 °C. The kinetic measurements were carried out with an oxygen sensor; the composition of the solution of degraded spermidine was analyzed with MS.

  18. Airborne flux measurements of biogenic isoprene over California

    Science.gov (United States)

    Misztal, P. K.; Karl, T.; Weber, R.; Jonsson, H. H.; Guenther, A. B.; Goldstein, A. H.

    2014-10-01

    Biogenic isoprene fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne Biogenic volatile organic compound (BVOC) Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a proton transfer reaction mass spectrometer (PTR-MS) and a wind radome probe to directly determine fluxes of isoprene over 7400 km of flight paths focusing on areas of California predicted to have the largest emissions. The fast Fourier transform (FFT) approach was used to calculate fluxes of isoprene over long transects of more than 15 km, most commonly between 50 and 150 km. The continuous wavelet transformation (CWT) approach was used over the same transects to also calculate instantaneous isoprene fluxes with localization of both frequency and time independent of non-stationarities. Fluxes were generally measured by flying consistently at 400 m ± 50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence determined in the racetrack-stacked profiles. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to basal emission factor (BEF) land-cover data sets used to drive BVOC emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m-2 h-1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. Even though the isoprene emissions from agricultural crop regions, shrublands, and coniferous forests were extremely low, observations at the Walnut Grove tower south of Sacramento demonstrate that isoprene oxidation products from the high emitting regions in the surrounding oak woodlands accumulate at night in

  19. Evolution of cyclonic eddies and biogenic fluxes in the northern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Nuncio, M.; PrasannaKumar, S.

    of westward propagating Rossby waves. The sediment trap data provided the observational evidence that eddy-induced biological productivity is an important mechanism in the Bay of Bengal that contributes significantly to the mid-depth biogenic flux....

  20. Light Absorption of Biogenic Aerosol Particles in Amazonia

    Science.gov (United States)

    Holanda, B. A.; Artaxo, P.; Ferreira De Brito, J.; Barbosa, H. M.; Andreae, M. O.; Saturno, J.; Pöhlker, C.; Holben, B. N.; Schafer, J.

    2014-12-01

    Aerosol absorption is a key issue in proper calculation of aerosol radiative forcing. Especially in the tropics with the dominance of natural biogenic aerosol and brown carbon, the so called anomalous absorption is of particular interest. A special experiment was designed to study the wavelength dependence of aerosol absorption for PM2.5 as well as for PM10 particles in the wet season in Central Amazonia. Aerosol analysis occurred from May to August 2014, in the ZF2 ecological reservation, situated at about 55 km North of Manaus in very pristine conditions Two 7 wavelengths AE33 Aethalometers were deployed measuring in parallel, but with a PM2.5 and PM10 inlets. Two MAAP (Multiangle Aerosol Absorption Photometer) were operated in parallel with the AE33 exactly at the same PM2.5 and PM10 inlets. Organic and elemental carbon was analyzed using collection with quartz filters and analysis using a Sunset OC/EC analyzer. Aerosol light scattering for 3 wavelengths was measured using Air Photon and TSI Nephelometers. Aerosol size distribution was measured with one TSI SMPS and a GRIMM OPC to have the size range from 10 nm to 10 micrometers. Particles were measured under dry conditions using diffusion dryers. Aerosol optical depth and absorption was also measured with an AERONET sunphotometer operated close to the site. As the experiment was run in the wet season, very low equivalent black carbon (EBC) were measured, with average concentrations around 50 ng/m³ during May, increasing to 130 ng/m³ in June and July. The measurements adjusted for similar wavelengths shows excellent agreement between the MAAP and AE33 for both inlets (PM2.5 and PM10). It was not possible statistically infer absorption from the coarse mode biogenic particles, since the absorption was completely dominated by fine mode particles. AERONET measurements shows very low values of AOD, at 0.17 at 500 nm and 0.13 at 870 nm, with very low absorption AOD values at 0.00086 at 676 nm and 0.0068 at 872 nm

  1. Biogenic hardparts: Difficult archives of the geological past (Invited)

    Science.gov (United States)

    Immenhauser, A.; Schone, B. R.; Hoffmann, R.; Niedermayr, A.

    2013-12-01

    Biomineralized exo- or endoskeletons of fossil marine invertebrates are widespread and diverse components of the Phanerozoic rock record of Earth's past and present oceans. Exoskeletons serve as protection against environmental pressure or predators, whilst endoskeletons can act as support or serve as an attachment for muscles and ligaments and hence as a mechanism for transmitting muscular forces. Biogenic hard parts represent sophisticated products resulting from the hierarchical interaction of inorganic minerals (95%) and macromolecular organic matrices, forming commonly less than 5%. The significance of many biogenic carbonate archives lies in the time-resolved growth patterns and their ability to record ambient environmental conditions in the form of multiple geochemical properties (multi-proxy archives) that have been widely used to assess past oceanic seawater properties. Here, we compile and review published work dealing with crystallization pathways of skeletal hard parts secreted by mollusks (i.e., bivalves and cephalopods) as well as brachiopods as widely used archives of ancient neritic epeiric settings. Bivalves and cephalopods (e.g., extinct ammonoids and belemnites and extant Sepia, Nautilus and Spirula) all form accretionary calcitic, aragonitic or vateritic skeletal hard parts. Despite the fact that mollusks and brachiopods form part of very different branches of the animal phylogenetic tree, their biomineralization strategies are surprisingly similar. Our main focus lies in a critical assessment of the complex pathways of ions and aquo-complexes from their source (seawater) to the final product (biomineral). We do this as an attempt to critically test the commonly held hypothesis that many fossil hard parts precipitated (under favorable conditions and pending subsequent diagenetic alteration) in equilibrium with seawater. Two main observations stand out: (1) the present knowledge on pathways and mechanisms (e.g., ion channel trans-membrane or

  2. Anthropogenic impact on biogenic Si pools in temperate soils

    Directory of Open Access Journals (Sweden)

    W. Clymans

    2011-05-01

    Full Text Available Human land use changes directly affect silica (Si mobilisation and Si storage in terrestrial ecosystems and influence Si export from the continents, although the magnitudes of the impact are unknown. Yet biogenic silica (BSi in soils is an understudied aspect. We have quantified and compared total biogenic (PSia and easily soluble (PSie Si pools at four sites along a gradient of disturbance in southern Sweden. An estimate of the magnitude of change in temperate continental BSi pools due to human disturbance is provided. Land use clearly affects BSi pools and their distribution. Total PSia and PSie for a continuous forested site at Siggaboda Nature Reserve (66 900 ± 22 800 kg SiO2 ha−1 and 952 ± 16 kg SiO2 ha−1 are significantly higher than disturbed land use types from the Råshult Culture Reserve including arable land (28 800 ± 7200 kg SiO2 ha−1 and 239 ± 91 kg SiO2 ha−1, pasture sites (27 300 ± 5980 kg SiO2 ha−1 and 370 ± 129 kg SiO2 ha−1 and grazed forest (23 600 ± 6370 kg SiO2 ha−1 and 346 ± 123 kg SiO2 ha−1. Vertical PSia and PSie profiles show significant (p<0.05 variation among the sites. These differences in size and distribution are interpreted as the long-term effect of reduced BSi replenishment and increased mobilisation of the PSia in disturbed soils. In temperate regions, total PSia showed a 10 % decline since agricultural development (3000BCE. Recent agricultural expansion (after 1700CE has resulted in an average export of 1.1 ± 0.8 Tmol Si yr−1, leading to an annual contribution of ca. 20 % to the global land-ocean Si flux carried by rivers. Human activities clearly exert a long-term influence on Si cycling in soils and

  3. Airborne flux measurements of biogenic volatile organic compounds over California

    Science.gov (United States)

    Misztal, P. K.; Karl, T.; Weber, R.; Jonsson, H. H.; Guenther, A. B.; Goldstein, A. H.

    2014-03-01

    Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT) approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT) approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi). Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF) landcover datasets used to drive biogenic VOC (BVOC) emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m-2 h-1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions, shrublands, and

  4. Humidity-dependent phase state of SOA particles from biogenic and anthropogenic precursors

    Directory of Open Access Journals (Sweden)

    E. Saukko

    2012-08-01

    Full Text Available The physical phase state (solid, semi-solid, or liquid of secondary organic aerosol (SOA particles has important implications for a number of atmospheric processes. We report the phase state of SOA particles spanning a wide range of oxygen to carbon ratios (O / C, used here as a surrogate for SOA oxidation level, produced in a flow tube reactor by photo-oxidation of various atmospherically relevant surrogate anthropogenic and biogenic volatile organic compounds (VOCs. The phase state of laboratory-generated SOA was determined by the particle bounce behavior after inertial impaction on a polished steel substrate. The measured bounce fraction was evaluated as a function of relative humidity and SOA oxidation level (O / C measured by an Aerodyne high resolution time of flight aerosol mass spectrometer (HR-ToF AMS.

    The main findings of the study are: (1 biogenic and anthropogenic SOA particles are found to be amorphous solid or semi-solid based on the measured bounced fraction (BF, which was typically higher than 0.6 on a 0 to 1 scale. A decrease in the BF is observed for most systems after the SOA is exposed to relative humidity of at least 80% RH, corresponding to a RH at impaction of 55%. (2 Long-chain alkanes have a low BF (indicating a "liquid-like", less viscous phase particles at low oxidation levels (BF < 0.2 ± 0.05 for O / C = 0.1. However, BF increases substantially upon increasing oxidation. (3 Increasing the concentration of sulphuric acid (H2SO4 in solid SOA particles (here tested for longifolene SOA causes a decrease in BF levels. (4 In the majority of cases the bounce behavior of the various SOA systems did not show correlation with the particle O / C. Rather, the molar mass of the gas-phase VOC precursor showed a positive correlation with the resistance to the RH-induced phase change of the formed SOA particles.

  5. Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions

    Science.gov (United States)

    Baghi, R.; Helmig, D.; Guenther, A.; Duhl, T.; Daly, R.

    2012-10-01

    Emissions of biogenic volatile organic compounds (BVOC) from urban trees during and after blooming were measured during spring and early summer 2009 in Boulder, Colorado. Air samples were collected onto solid adsorbent cartridges from branch enclosures on the tree species crabapple (Malus sp.), horse chestnut (Aesculus carnea, "Ft. McNair"), honey locust (Gleditsia triacanthos, "Sunburst"), and hawthorn (Crataegus laevigata, "Pauls Scarlet"). These species constitute ~ 65% of the insect-pollinated fraction of the flowering tree canopy (excluding catkin-producing trees) from the street area managed by the City of Boulder. Samples were analyzed for C10-C15 BVOC by thermal desorption and gas chromatography coupled to a flame ionization detector and a mass spectrometer (GC/FID/MS). Identified emissions and emission rates from these four tree species during the flowering phase were found to vary over a wide range. Monoterpene emissions were identified for honey locust, horse chestnut and hawthorn. Sesquiterpene emissions were observed in horse chestnut and hawthorn samples. Crabapple flowers were found to emit significant amounts of benzyl alcohol and benzaldehyde. Floral BVOC emissions increased with temperature, generally exhibiting exponential temperature dependence. Changes in BVOC speciation during and after the flowering period were observed for every tree studied. Emission rates were significantly higher during the blooming compared to the post-blooming state for crabapple and honey locust. The results were scaled to the dry mass of leaves and flowers contained in the enclosure. Only flower dry mass was accounted for crabapple emission rates as leaves appeared at the end of the flowering period. Total normalized (30 °C) monoterpene emissions from honey locust were higher during flowering (5.3 μgC g-1 h-1) than after flowering (1.2 μgC g-1 h-1). The total normalized BVOC emission rate from crabapple (93 μgC g-1 h-1) during the flowering period is of the same

  6. Elucidating Protein Involvement in the Stabilization of the Biogenic Silver Nanoparticles

    Science.gov (United States)

    Ballottin, Daniela; Fulaz, Stephanie; Souza, Michele L.; Corio, Paola; Rodrigues, Alexandre G.; Souza, Ana O.; Gaspari, Priscyla M.; Gomes, Alexandre F.; Gozzo, Fábio; Tasic, Ljubica

    2016-06-01

    Silver nanoparticles (AgNPs) have been broadly used as antibacterial and antiviral agents. Further, interests for green AgNP synthesis have increased in recent years and several results for AgNP biological synthesis have been reported using bacteria, fungi and plant extracts. The understanding of the role and nature of fungal proteins, their interaction with AgNPs and the subsequent stabilization of nanosilver is yet to be deeply investigated. Therefore, in an attempt to better understand biogenic AgNP stabilization with the extracellular fungal proteins and to describe these supramolecular interactions between proteins and silver nanoparticles, AgNPs, produced extracellularly by Aspergillus tubingensis—isolated as an endophytic fungus from Rizophora mangle—were characterized in order to study their physical characteristics, identify the involved proteins, and shed light into the interactions among protein-NPs by several techniques. AgNPs of around 35 nm in diameter as measured by TEM and a positive zeta potential of +8.48 mV were obtained. These AgNPs exhibited a surface plasmon resonance (SPR) band at 440 nm, indicating the nanoparticles formation, and another band at 280 nm, attributed to the electronic excitations in tryptophan, tyrosine, and/or phenylalanine residues in fungal proteins. Fungal proteins were covalently bounded to the AgNPs, mainly through S-Ag bonds due to cysteine residues (HS-) and with few N-Ag bonds from H2N- groups, as verified by Raman spectroscopy. Observed supramolecular interactions also occur by electrostatic and other protein-protein interactions. Furthermore, proteins that remain free on AgNP surface may perform hydrogen bonds with other proteins or water increasing thus the capping layer around the AgNPs and consequently expanding the hydrodynamic diameter of the particles (~264 nm, measured by DLS). FTIR results enabled us to state that proteins adsorbed to the AgNPs did not suffer relevant secondary structure alteration upon

  7. Seasonal variations of biogenic secondary organic aerosol tracers in ambient aerosols from Alaska

    Science.gov (United States)

    Haque, Md. Mozammel; Kawamura, Kimitaka; Kim, Yongwon

    2016-04-01

    We investigated total suspended particles (TSP) collected from central Alaska, USA for molecular compositions of secondary organic aerosol (SOA) derived from the oxidation of biogenic volatile organic compounds (BVOCs). Isoprene-, α-/β-pinene- and β-caryophyllene-SOA tracers were determined using gas chromatography-mass spectrometry. The concentration ranges of isoprene, α-/β-pinene and β-caryophyllene oxidation products were 0.02-18.6 ng m-3 (ave. 4.14 ng m-3), 0.42-8.24 ng m-3 (2.01 ng m-3) and 0.10-9 ng m-3 (1.53 ng m-3), respectively. Isoprene-SOA tracers showed higher concentrations in summer (ave. 8.77 ng m-3), whereas α-/β-pinene- and β-caryophyllene-SOA tracers exhibited highest levels in spring (3.55 ng m-3) and winter (4.04 ng m-3), respectively. β-Caryophyllinic acid and levoglucosan showed a positive correlation, indicating that biomass burning may be a major source for β-caryophyllene. We found that mean contributions of isoprene oxidation products to organic carbon (OC) and water-soluble organic (WSOC) (0.56% and 1.2%, respectively) were higher than those of α-/β-pinene (0.31% and 0.55%) and β-caryophyllene (0.08% and 0.13%). Using a tracer-based method, we estimated the concentrations of secondary organic carbon (SOC) produced from isoprene, α-/β-pinene and β-caryophyllene to be 0.66-718 ngC m-3 (ave. 159 ngC m-3), 7.4-143 ngC m-3 (35 ngC m-3) and 4.5-391 ngC m-3 (66.3 ngC m-3), respectively. Based on SOA tracers, this study suggests that isoprene is a more important precursor for the production of biogenic SOA than α-/β-pinene and β-caryophyllene in subarctic Alaska.

  8. Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions

    Directory of Open Access Journals (Sweden)

    R. Baghi

    2012-03-01

    Full Text Available Emissions of biogenic volatile organic compounds (BVOC from urban trees during and after blooming were measured during spring and early summer 2009 in Boulder, Colorado. Air samples were collected onto solid adsorbent cartridges from branch enclosures on the tree species crabapple, horse chestnut, honey locust, and hawthorn. These species constitute ~65 % of the insect-pollinated fraction of the flowering tree canopy (excluding catkin-producing trees from the street area managed by the City of Boulder. Samples were analyzed for C10–C15 BVOC by thermal desorption and gas chromatography coupled to a flame ionization detector and a mass spectrometer (GC/FID/MS. Identified emissions and emission rates from these four tree species during the flowering phase were found to vary over a wide range. Monoterpene emissions were identified for honey locust, horse chestnut and hawthorn. Sesquiterpene emissions were observed in horse chestnut and hawthorn samples. Crabapple flowers were found to emit significant amounts of benzyl alcohol and benzaldehyde. Floral BVOC emissions increased with temperature, generally exhibiting exponential temperature dependence. Changes in BVOC speciation during and after the flowering period were observed for every tree studied. Emission rates were significantly higher during the blooming compared to the vegetative state for crabapple and honey locust. Total normalized (30 °C monoterpene emissions from honey locust were higher during flowering (5.26 μg Cg−1 h−1 than after flowering (1.23 μg Cg−1 h−1. The total normalized BVOC emission rate from crabapple (93 μg Cg−1 h−1 during the flowering period is of the same order as isoprene emissions from oak trees, which are among the highest BVOC emissions observed from plants to date. These findings illustrate that during the relatively brief springtime flowering period, floral

  9. Metabolism of biogenic amines in acute cerebral ischemia: Influence of systemic hyperglycemia

    Directory of Open Access Journals (Sweden)

    Milovanović Aleksandar

    2012-01-01

    Full Text Available Dopamine, norepinephrine and serotonin are biogenic amines which are transmitters of the central nervous system. The effects of ischemia on the brain parenchyma depends on many factors, such is the mechanism of blood flow interruption, velocity of the occurring blood flow interruption, duration of an ischemic episode, organization of anatomical structures of the brain blood vessels etc., which all influence the final outcome. During interruption of the brain circulation in experimental or clinical conditions, neurotransmitter metabolism, primarily of biogenic amines, is disturbed. Many researches with various experimental models of complete ischemia reported a decrease in the content of norepinephrine, dopamine and serotonin in the CNS tissue. It was proven that hyperglycemia can drastically increase cerebral injury followed by short-term cerebral ischemia. Considering the fact that biogenic amines (dopamine, norepinephrine and serotonin influence the size of neurologic damage, as well as the fact that in hyperglycemic conditions infarct size (from the morphological aspect is larger relative to normoglycemic status, the intention was to evaluate the role of biogenic amines in occurrence of damage in conditions of hyperglycemia, i.e. in the case of brain apoplexia in diabetics. Analysis of biogenic amines metabolism in states of acute hyperglycemia, as well as analysis of the effects of reversible and irreversible brain ischemia on metabolism of serotonin, dopamine and norepinephrine, showed that acute hyperglycemia slows down serotonin, dopamine and norepinephrine metabolism in the cerebral cortex and n. caudatus. Brain ischemia in normoglycemic animals by itself has no influence on biogenic amines metabolism, but the effect of ischemia becomes apparent during reperfusion. In recirculation, which corresponds to the occurrences in penumbra, release of biogenic amines is uncontrolled and increased. Brain ischemia in acute hyperglycemic animals

  10. Unusual biogenic calcite structures in two shallow lakes, James Ross Island, Antarctica

    Science.gov (United States)

    Elster, J.; Nedbalová, L.; Vodrážka, R.; Láska, K.; Haloda, J.; Komárek, J.

    2016-01-01

    The floors of two shallow endorheic lakes, located on volcanic surfaces on James Ross Island, are covered with calcareous organosedimentary structures. Their biological and chemical composition, lake water characteristics, and seasonal variability of the thermal regime are introduced. The lakes are frozen down to the bottom for 8-9 months a year and their water chemistry is characterised by low conductivity and neutral to slightly alkaline pH. The photosynthetic microbial mat is composed of filamentous cyanobacteria and microalgae that are considered to be Antarctic endemic species. The mucilaginous black biofilm is covered by green spots formed by a green microalga and the macroscopic structures are packed together with fine material. Thin sections consist of rock substrate, soft biofilm, calcite spicules and mineral grains originating from different sources. The morphology of the spicules is typical of calcium carbonate monocrystals having a layered structure and specific surface texture, which reflect growth and degradation processes. The spicules' chemical composition and structure correspond to pure calcite. The lakes' age, altitude, morphometry, geomorphological and hydrological stability, including low sedimentation rates, together with thermal regime predispose the existence of this community. We hypothesise that the precipitation of calcite is connected with the photosynthetic activity of the green microalgae that were not recorded in any other lake in the region. This study has shown that the unique community producing biogenic calcite spicules is quite different to any yet described.

  11. Vaginal Biogenic Amines: Biomarkers of Bacterial Vaginosis or Precursors to Vaginal Dysbiosis?

    Directory of Open Access Journals (Sweden)

    Tiffanie Maree Nelson

    2015-09-01

    Full Text Available Bacterial vaginosis (BV is the most common vaginal disorder among reproductive age women. One clinical indicator of BV is a ‘fishy’ odor. This odor has been associated with increases in several biogenic amines (BAs that may serve as important biomarkers. Within the vagina, BA production has been linked to various vaginal taxa, yet their genetic capability to synthesize BAs is unknown. Using a bioinformatics approach, we show that relatively few vaginal taxa are predicted to be capable of producing BAs. Many of these taxa (Dialister, Prevotella, Parvimonas, Megasphaera, Peptostreptococcus, and Veillonella spp. are more abundant in the vaginal microbial community state type (CST IV, which is depleted in lactobacilli. Several of the major Lactobacillus species (L. crispatus, L. jensenii, and L. gasseri were identified as possessing gene sequences for proteins predicted to be capable of putrescine production. Finally, we show in a small cross sectional study of 37 women that the BAs putrescine, cadaverine and tyramine are significantly higher in CST IV over CSTs I and III. These data support the hypothesis that BA production is conducted by few vaginal taxa and may be important to the outgrowth of BV-associated (vaginal dysbiosis vaginal bacteria.

  12. Synthesis of gold and silver nanoparticles using leaf extract of Perilla frutescens--a biogenic approach.

    Science.gov (United States)

    Basavegowda, Nagaraj; Lee, Yong Rok

    2014-06-01

    The present investigation demonstrates a rapid biogenic approach for the synthesis of gold and silver nanoparticles using biologically active and medicinal important Perilla frutescens leaf extract as a reducing and stabilizing agent under ambient conditions. Gold and silver nanoparticles were first synthesized from Perilla frutescens leaf extract which was used as a vegetable and in traditional medicines for a long time in Korea, Japan, and China. The nanoparticles obtained were characterized by UV-vis spectroscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Surface plasmon resonance spectra of gold and silver nanoparticles were obtained at 540 and 430 nm and triangular and spherical shape respectively. TEM studies showed that the particle sizes of gold and silver nanoparticles ranges -50 nm and -40 nm respectively. X-ray diffraction studies confirm that the biosynthesized nanoparticles were crystalline gold and silver. Fourier transform infra-red spectroscopy revealed that biomolecules were involved in the synthesis and capping of the nanoparticles produced. XRD and EDX confirmed the formation of gold and silver nanoparticles. This is a simple, efficient and rapid method to synthesize gold and silver nanoparticles at room temperature without use of toxic chemicals. Obtained gold and silver nanoparticles can be used in various biomedical and biotechnological applications.

  13. Vitis vinifera juice ameliorates depression-like behavior in mice by modulating biogenic amine neurotransmitters

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam

    2015-12-01

    Full Text Available The advantageous effects of Vitis vinifera juice on depressive model mice were examined utilizing a blend of behavioral evaluations and biogenic amine neurotransmitter estimations. During the behavioral evaluations, immobility time on the forced swimming test and tail suspension test were measured in unstressed and immobilization-induced stressed mice. V. vinifera juice (4 mL/kg and 8 mL/kg and fluoxetine (20 mg/kg produced a significant decrease in immobility time of both unstressed and stressed mice when compared with their respective saline-treated control groups in both paradigms. Neurotransmitters were measured using high-performance liquid chromatography with electrochemical detector. V. vinifera juice raised the levels of both serotonin (p<0.001 and noradrenalin (p<0.001 in brain tissue. These outcomes give significant mechanistic insights into the protective effect of V. vinifera juice against depressive disorders. Our results showed that V. vinifera juice could relieve depressive manifestations in the rodent model of depression.

  14. Polyvinyl alcohol electrospun nanofibers containing Ag nanoparticles used as sensors for the detection of biogenic amines

    Science.gov (United States)

    Marega, Carla; Maculan, Jenny; Rizzi, Gian Andrea; Saini, Roberta; Cavaliere, Emanuele; Gavioli, Luca; Cattelan, Mattia; Giallongo, Giuseppe; Marigo, Antonio; Granozzi, Gaetano

    2015-02-01

    Polyvinyl alcohol (PVA) electrospun nanofibers containing Ag nanoparticles (NPs) have been deposited on glass substrates. The aim of the work was to test the feasibility of this approach for the detection of biogenic amines by using either the Ag localized surface plasmon resonance quenching caused by the adsorption of amines on Ag NPs or by detecting the amines by surface enhanced Raman spectroscopy (SERS) after adsorption, from the gas phase, on the metal NPs. Two different approaches have been adopted. In the first one an ethanol/water solution containing AgNO3 was used directly in the electrospinning apparatus. In this way, a simple heat treatment of the nanofibers mat was sufficient to obtain the formation of Ag NPs inside the nanofibers and a partial cross-link of PVA. In the second procedure, the Ag NPs were deposited on PVA nanofibers by using the supersonic cluster beam deposition method, so that a beam of pure Ag NPs of controlled size was obtained. Exposure of the PVA mat to the beam produced a uniform distribution of the NPs on the nanofibers surface. Ethylendiamine vapors and volatile amines released from fresh shrimp meat were chemisorbed on the nanofibers mats. A SERS spectrum characterized by a diagnostic Ag-N stretching vibration at 230 cm-1 was obtained. The results allow to compare the two different approaches in the detection of ammines.

  15. Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments

    Science.gov (United States)

    Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

    2017-01-01

    Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). In this study we calculated the GWPbio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWPbio factors ranged from 0.13–0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWPbio. Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWPbio and energy conversion efficiency. By considering the GWPbio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWPbio. PMID:28045111

  16. Investigation of colloidal biogenic sulfur flocculation: Optimization using response surface analysis.

    Science.gov (United States)

    Chen, Fan; Yuan, Ye; Chen, Chuan; Zhao, Youkang; Tan, Wenbo; Huang, Cong; Xu, Xijun; Wang, Aijie

    2016-04-01

    The colloidal properties of biogenic elemental sulfur (S(0)) cause solid-liquid separation problems, such as poor settling and membrane fouling. In this study, the separation of S(0) from bulk liquids was performed using flocculation. Polyaluminum chloride (PAC), polyacrylamide (PAM) and microbial flocculant (MBF) were compared to investigate their abilities to flocculate S(0) produced during the treatment of sulfate-containing wastewater. A novel approach with response surface methodology (RSM) was employed to evaluate the effects and interactions of flocculant dose, pH and stirring intensity, on the treatment efficiency in terms of the S(0) flocculation and the supernatant turbidity removal. The dose optimization results indicated that the S(0) flocculation efficiency decreased in the following order PAC>MBF>PAM. Optimum S(0) flocculation conditions were observed at pH4.73, a stirring speed of 129 r/min and a flocculant dose of 2.42 mg PAC/mgS. During optimum flocculation conditions, the S(0) flocculation rate reached 97.53%. Confirmation experiments demonstrated that employing PAC for S(0) flocculation is feasible and RSM is an efficient approach for optimizing the process of S(0) flocculation. The results provide basic parameters and conditions for recovering sulfur during the treatment of sulfate-laden wastewaters.

  17. Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments

    Science.gov (United States)

    Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

    2017-01-01

    Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). In this study we calculated the GWPbio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWPbio factors ranged from 0.13–0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWPbio. Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWPbio and energy conversion efficiency. By considering the GWPbio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWPbio.

  18. In Vivo Evaluation of Complex Biogenic Silver Nanoparticle and Enoxaparin in Wound Healing

    Directory of Open Access Journals (Sweden)

    P. D. Marcato

    2015-01-01

    Full Text Available The burns treatment is difficult, uncomfortable for the patient, and expensive for health system. Due to antimicrobial properties of silver nanoparticles (AgNP, these particles can avoid bacterial infection in wound and accelerate the wound healing. Furthermore, the complexation of AgNP with enoxaparin (low molecular weight heparin may improve the healing process of lesions due to anti-inflammatory and angiogenic activity of enoxaparin (Enox. The aim of this study was evaluated the activity and toxicity of biogenic AgNP and AgNP complexed with Enox in in vivo burn wound model. AgNP was produced by biosynthesis method using Fusarium oxysporum. AgNP (20–40 nm exhibited high stability due to protein capping around the particles that was confirmed by TEM, fluorescence spectroscopy, and FTIR. The wound contraction in in vivo model, after 28 days of treatment, was 55, 89, 91, and 95% for control, Enox, AgNP, and AgNP-Enox groups, respectively. No clear toxic effects in the biochemistry and hematological parameters were verified in all treated groups. However, in the AgNP-Enox group, a statistically significant increase in the urea levels was observed indicating increased proteolysis due to inflammation process. The results demonstrated that the complex AgNP-Enox is interesting for wound healing decreasing the time of lesions healing.

  19. Changes in biogenic carbon flow in response to sea surface warming.

    Science.gov (United States)

    Wohlers, Julia; Engel, Anja; Zöllner, Eckart; Breithaupt, Petra; Jürgens, Klaus; Hoppe, Hans-Georg; Sommer, Ulrich; Riebesell, Ulf

    2009-04-28

    The pelagic ocean harbors one of the largest ecosystems on Earth. It is responsible for approximately half of global primary production, sustains worldwide fisheries, and plays an important role in the global carbon cycle. Ocean warming caused by anthropogenic climate change is already starting to impact the marine biota, with possible consequences for ocean productivity and ecosystem services. Because temperature sensitivities of marine autotrophic and heterotrophic processes differ greatly, ocean warming is expected to cause major shifts in the flow of carbon and energy through the pelagic system. Attempts to integrate such biological responses into marine ecosystem and biogeochemical models suffer from a lack of empirical data. Here, we show, using an indoor-mesocosm approach, that rising temperature accelerates respiratory consumption of organic carbon relative to autotrophic production in a natural plankton community. Increasing temperature by 2-6 degrees C hence decreased the biological drawdown of dissolved inorganic carbon in the surface layer by up to 31%. Moreover, warming shifted the partitioning between particulate and dissolved organic carbon toward an enhanced accumulation of dissolved compounds. In line with these findings, the loss of organic carbon through sinking was significantly reduced at elevated temperatures. The observed changes in biogenic carbon flow have the potential to reduce the transfer of primary produced organic matter to higher trophic levels, weaken the ocean's biological carbon pump, and hence provide a positive feedback to rising atmospheric CO(2).

  20. Using biogenic sulfur gases as remotely detectable biosignatures on anoxic planets.

    Science.gov (United States)

    Domagal-Goldman, Shawn D; Meadows, Victoria S; Claire, Mark W; Kasting, James F

    2011-06-01

    We used one-dimensional photochemical and radiative transfer models to study the potential of organic sulfur compounds (CS(2), OCS, CH(3)SH, CH(3)SCH(3), and CH(3)S(2)CH(3)) to act as remotely detectable biosignatures in anoxic exoplanetary atmospheres. Concentrations of organic sulfur gases were predicted for various biogenic sulfur fluxes into anoxic atmospheres and were found to increase with decreasing UV fluxes. Dimethyl sulfide (CH(3)SCH(3), or DMS) and dimethyl disulfide (CH(3)S(2)CH(3), or DMDS) concentrations could increase to remotely detectable levels, but only in cases of extremely low UV fluxes, which may occur in the habitable zone of an inactive M dwarf. The most detectable feature of organic sulfur gases is an indirect one that results from an increase in ethane (C(2)H(6)) over that which would be predicted based on the planet's methane (CH(4)) concentration. Thus, a characterization mission could detect these organic sulfur gases-and therefore the life that produces them-if it could sufficiently quantify the ethane and methane in the exoplanet's atmosphere.

  1. Operation of marine diesel engines on biogenic fuels: modification of emissions and resulting climate effects.

    Science.gov (United States)

    Petzold, Andreas; Lauer, Peter; Fritsche, Uwe; Hasselbach, Jan; Lichtenstern, Michael; Schlager, Hans; Fleischer, Fritz

    2011-12-15

    The modification of emissions of climate-sensitive exhaust compounds such as CO(2), NO(x), hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fuel life cycle analysis which included land use changes associated with the growth of energy plants. Emissions of CO(2) and NO(x) per kWh were found to be similar for fossil fuels and biogenic fuels. PM mass emission was reduced to 10-15% of HFO emissions for all low-sulfur fuels including MGO as a fossil fuel. Black carbon emissions were reduced significantly to 13-30% of HFO. Changes in emissions were predominantly related to particulate sulfate, while differences between low-sulfur fossil fuels and low-sulfur biogenic fuels were of minor significance. GHG emissions from the biogenic fuel life cycle (FLC) depend crucially on energy plant production conditions and have the potential of shifting the overall GHG budget from positive to negative compared to fossil fuels.

  2. Characteristics of Carbon Isotopes of Alkane Components and Identification Marks of Biogenic Gases in China

    Institute of Scientific and Technical Information of China (English)

    戴金星; 陈英

    1994-01-01

    The carbon isotope composition of alkane component in biogenic gases of China has the following characteristics:with the increase of carbon number of the alkane molecules in biogenic gases, (i) the distribution range of the δ13C values and their main frequency sections become narrower, and both the heaviest and the lightest δ13C boundary values shift to their heavier end; (ii) the δ13C values of ethane and propane in biogenic gases present a positive linear relationship and (iii) the values of δ13C1, δ13C2 and δ13C3 tend to become heavier with the increase of heavy alkane component (C2+3) in biogenic gases. The authors studied the relationship between the δ13C values and the amount of heavy alkane components in biogenic gases (δ13C1 -C2+3(%). δ13C2 -C2+3(%) ,δ13C3-C2+3(%) for the first time and set up the interrelated regression equations between δ13C and C2+3 content (C2+3%), and advance that δ13C1< -55‰ and C2+3<0. 5% are two fine marks for identification of biogenic gases of China. δ13C

  3. HOx Radical Behavior in Urban, Biogenic and Mixed Environments

    Science.gov (United States)

    Cantrell, C. A.; Mauldin, L.; Schardt, N.; Mukherjee, A. D.

    2014-12-01

    The importance of HOx radicals in tropospheric chemistry is well-recognized. These roles include control of the lifetimes of a wide variety of trace gases, and control of photochemical ozone formation. The continued advance in understanding comes from laboratory investigations and field observations especially as part of comprehensive measurement campaigns. We participated in two recent observational campaigns aboard the NSF/NCAR C-130 aircraft platform: NOMADSS (Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks) and FRAPPE (Front Range Atmospheric Pollution and Photochemistry Experiment). During these studies, a wide varieties of air masses were sampled ranging from fresh urban to rural both without and without biogenic influence to marine, and including the impacts of emissions from oil and gas extraction and animal production. Among the wide variety of parameters and species related to tropospheric chemistry that were measured, our group made observations of HOx and related species: OH, HO2, HO2+RO2, H2SO4, and stabilized Criegee intermediates (sCIs) using selected ion chemical ionization mass spectrometry. The paper discusses the functional dependence of these species on other measures of the chemical environment (e.g. NO, VOCs, j-values) as well as comparison of model estimates with the observations.

  4. Analysis of Some Biogenic Amines by Micellar Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Irena Malinowska

    2012-01-01

    Full Text Available Micellar liquid chromatography (MLC with the use of high performance liquid chromatography (HPLC was used to determine some physicochemical parameters of six biogenic amines: adrenaline, dopamine, octopamine, histamine, 2-phenylethylamine, and tyramine. In this paper, an influence of surfactant’s concentration and pH of the micellar mobile phase on the retention of the tested substances was examined. To determine the influence of surfactant’s concentration on the retention of the tested amines, buffered solutions (at pH 7.4 of ionic surfactant—sodium dodecyl sulfate SDS (at different concentrations with acetonitrile as an organic modifier (0.8/0.2 v/v were used as the micellar mobile phases. To determine the influence of pH of the micellar mobile phase on the retention, mobile phases contained buffered solutions (at different pH values of sodium dodecyl sulfate SDS (at 0.1 M with acetonitrile (0.8/0.2 v/v. The inverse of value of retention factor (1/ versus concentration of micelles ( relationships were examined. Other physicochemical parameters of solutes such as an association constant analyte—micelle (ma—and partition coefficient of analyte between stationary phase and water (hydrophobicity descriptor (swΦ were determined by the use of Foley’s equation.

  5. Biogenic Emissions of Volatile Organic Compounds by Urban Forests

    Institute of Scientific and Technical Information of China (English)

    CENTRITTOMauro; LIUShirong; LORETOFrancesco

    2005-01-01

    All plants emit a wide range of volatile compounds, the so-called biogenic volatile organic compounds (BVOC). BVOC emissions have received increased scientific attention in the last two decades because they may profoundly influence the chemical and physical properties of the atmosphere, and may modulate plant tolerance to heat, pollutants, oxidative stress and abiotic stresses, and affect plant-plant and plant-insect interactions. Urban forestry may have a high impact on atmospheric composition, air quality, environment,and quality of life in urban areas. However, few studies have been carried out where the emission of BVOC could have important consequence for the quality of air and contribute to pollution episodes. A screening of BVOC emission by the mixed stand constituting urban forests is therefore required if emissions are to be reliably predicted. Monitoring the emission rates simultaneously with measurements of air quality, plant physiology and micrometeorology on selected urban forests, will allow detailed quantitative information on the inventory of BVOC emissions by urban vegetation to be compiled. This information will make it possible to propose an innovative management of urban vegetation in cities characterised by heavy emissions of anthropogenic pollutants, aiming at the abatement of BVOC emissions through the introduction or selection of non-BVOC emitting species in urban areas subjected to pollution episodes and in the new afforestation areas covering peri-urban parks, green belts and green corridors between peri-urban rural areas and the conurbations.

  6. Ambient Gas-Particle Partitioning of Tracers for Biogenic Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Isaacman-VanWertz, Gabriel; Yee, Lindsay D.; Kreisberg, Nathan M.; Wernis, Rebecca; Moss, Joshua A.; Hering, Susanne V.; de Sa, Suzanne; Martin, Scot T.; Alexander, Mikaela L.; Palm, Brett B.; Hu, Weiwei; Campuzano-Jost, Pedro; Day, Douglas; Jimenez, Jose L.; Riva, Matthieu; Surratt, Jason D.; Viegas, Juarez; Manzi, Antonio; Edgerton, Eric S.; Baumann, K.; Souza, Rodrigo A.; Artaxo, Paulo; Goldstein, Allen H.

    2016-08-23

    Exchange of atmospheric organic compounds between gas and particle phases is important in the production and chemistry of particle-phase mass but is poorly understood due to a lack of simultaneous measurements in both phases of individual compounds. Measurements of particle- and gas phase organic compounds are reported here for the southeastern United States and central Amazonia. Polyols formed from isoprene oxidation contribute 8% and 15% on average to particle-phase organic mass at these sites but are also observed to have substantial gas-phase concentrations contrary to many models that treat these compounds as nonvolatile. The results of the present study show that the gas-particle partitioning of approximately 100 known and newly observed oxidation products is not well explained by environmental factors (e.g., temperature). Compounds having high vapor pressures have higher particle fractions than expected from absorptive equilibrium partitioning models. These observations support the conclusion that many commonly measured biogenic oxidation products may be bound in low-volatility mass (e.g., accretion products, inorganic organic adducts) that decomposes to individual compounds on analysis. However, the nature and extent of any such bonding remains uncertain. Similar conclusions are reach for both study locations, and average particle fractions for a given compound are consistent within similar to 25% across measurement sites.

  7. A marine biogenic source of atmospheric ice-nucleating particles

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T. W.; Ladino, L. A.; Alpert, Peter A.; Breckels, M. N.; Brooks, I. M.; Browse, J.; Burrows, Susannah M.; Carslaw, K. S.; Huffman, J. A.; Judd, C.; Kilthau, W. P.; Mason, R. H.; McFiggans, Gordon; Miller, L. A.; Najera, J.; Polishchuk, E. A.; Rae, S.; Schiller, C. L.; Si, M.; Vergara Temprado, J.; Whale, Thomas; Wong, J P S; Wurl, O.; Yakobi-Hancock, J. D.; Abbatt, JPD; Aller, Josephine Y.; Bertram, Allan K.; Knopf, Daniel A.; Murray, Benjamin J.

    2015-09-09

    The formation of ice in clouds is facilitated by the presence of airborne ice nucleating particles1,2. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice3–11. Here we show that material in the sea surface microlayer, which is enriched in surface active organic material representative of that found in sub-micron sea- spray aerosol12–21, nucleates ice under conditions that occur in mixed-phase clouds and high-altitude ice clouds. The ice active material is likely biogenic and is less than ~0.2 ?m in size. We also show that organic material (exudate) released by a common marine diatom nucleates ice when separated from cells and propose that organic material associated with phytoplankton cell exudates are a candidate for the observed ice nucleating ability of the microlayer samples. By combining our measurements with global model simulations of marine organic aerosol, we show that ice nucleating particles of marine origin are dominant in remote marine environments, such as the Southern Ocean, the North Pacific and the North Atlantic.

  8. Producing Presences

    OpenAIRE

    Mandagará, Pedro

    2008-01-01

    Resenha de MENDES, Victor K.; ROCHA, João Cezar de Castro (Eds.). Producing Presences: branching out from Gumbrecht’s work. Dartmouth, Massachusetts: University of Massachusetts Dartmouth, 2007. (Adamastor book series, 2)

  9. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Peter D.; Hackley, Paul C. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Breland, F. Clayton Jr. [Louisiana Department of Natural Resources, 617 North 3rd Street, Baton Rouge, LA 70802 (United States)

    2008-10-02

    coal gases primarily are generated in saline formation water by bacterial reduction of CO{sub 2}. Shallow (< 150 m) Wilcox coal beds containing freshwater have little or no biogenic gas. Molecular and isotopic analyses of gas samples collected from conventional gas and oil wells suggests that both biogenic and thermogenic gases are present in and adjacent to the Wilcox intervals that contain biogenic coal gases. Oil, probably sourced from thermally mature, down-structural-dip parts of the Wilcox Group, is produced from sandstones within the coal-bearing interval. Gas chromatograms of C{sub 10+} saturated hydrocarbons from Wilcox oils show a depletion of n-alkanes probably resulting from biodegradation of the oil. Isotopic composition of the gases associated with the oils is of mixed themogenic and biogenic origin (average {delta}{sup 13}C{sub CH4} = - 44.4 permille VPDB, and average {delta}D{sub CH4} = - 182.4 permille VSMOW). (author)

  10. Molecular composition of aged secondary organic aerosol generated from a mixture of biogenic volatile compounds using ultrahigh resolution mass spectrometry

    Directory of Open Access Journals (Sweden)

    I. Kourtchev

    2015-02-01

    Full Text Available Field observations over the past decade indicate that a significant fraction of organic aerosol in remote areas may contain highly oxidised molecules. Aerosol processing or further oxidation (ageing of organic aerosol has been suggested to be responsible for their formation through heterogeneous uptake of oxidants and multigenerational oxidation of vapours by OH radicals. In this study we investigated the influence of several ageing processes on the molecular composition of secondary organic aerosols (SOA using direct infusion and liquid chromatography ultrahigh resolution mass spectrometry. SOA was formed in simulation chamber experiments from ozonolysis of a mixture of four biogenic volatile organic compounds (BVOC: α-pinene, β-pinene, Δ3-carene and isoprene. The SOA was subsequently aged under three different sets of conditions: in the dark in the presence of residual ozone, with UV irradiation and OH radicals, and using UV light only. Among all studied conditions, only OH radical-initiated ageing was found to influence the molecular composition of the aerosol and showed an increase in carbon oxidation state (OSC and elemental O/C ratios of the SOA components. None of the ageing processes produced an observable effect on the oligomers formed from ozonolysis of the BVOC mixture, which were found to be equally abundant in both "fresh" and "aged" SOA. Additional experiments using α-pinene as the sole precursor demonstrated that oligomers are an important group of compounds in SOA produced from both ozonolysis and OH radical-initiated oxidation processes; however, a completely different set of oligomers is formed under these two oxidation regimes. SOA from the OH radical-initiated α-pinene oxidation had a significantly higher overall OSC and O/C compared to that from pure ozonolysis experiments confirming that the OH radical reaction is more likely to be responsible for the occurrence of highly oxidised species in ambient biogenic SOA.

  11. Is the production of the biogenic amines tyramine and putrescine a species-level trait in enterococci?

    Science.gov (United States)

    Ladero, Victor; Fernández, María; Calles-Enríquez, Marina; Sánchez-Llana, Esther; Cañedo, Elena; Martín, M Cruz; Alvarez, Miguel A

    2012-05-01

    Biogenic amines (BA) are toxic nitrogenous compounds that can be accumulated in foods via the microbial decarboxylation of certain amino acids. Lactic acid bacteria (LAB) strains belonging to different species and genera have been described as BA producers and are mainly responsible for their synthesis in fermented foods. It is generally accepted that the capacity to produced BAs is strain-dependent. However, the large number of enterococci identified as BA producers suggests that the aminogenic trait may be a species-level characteristic. Enterococcus faecalis, Enterococcus faecium and Enterococcus durans strains of different origin were analysed to determine their capacity to produce tyramine and putrescine. The presence of the genes responsible for this and the identity of their flanking regions were checked by PCR. The results suggest that tyramine biosynthesis is a species-level characteristic in E. faecalis, E. faecium and E. durans. Putrescine synthesis was found to be a species-level trait of E. faecalis, with production occurring via the agmatine deamination pathway. Some E. faecium strains of human origin also produced putrescine; this trait was probably acquired via horizontal gene transfer.

  12. Stable silicon isotope signatures of marine pore waters - Biogenic opal dissolution versus authigenic clay mineral formation

    Science.gov (United States)

    Ehlert, Claudia; Doering, Kristin; Wallmann, Klaus; Scholz, Florian; Sommer, Stefan; Grasse, Patricia; Geilert, Sonja; Frank, Martin

    2016-10-01

    Dissolved silicon isotope compositions have been analysed for the first time in pore waters (δ30SiPW) of three short sediment cores from the Peruvian margin upwelling region with distinctly different biogenic opal content in order to investigate silicon isotope fractionation behaviour during early diagenetic turnover of biogenic opal in marine sediments. The δ30SiPW varies between +1.1‰ and +1.9‰ with the highest values occurring in the uppermost part close to the sediment-water interface. These values are of the same order or higher than the δ30Si of the biogenic opal extracted from the same sediments (+0.3‰ to +1.2‰) and of the overlying bottom waters (+1.1‰ to +1.5‰). Together with dissolved silicic acid concentrations well below biogenic opal saturation, our collective observations are consistent with the formation of authigenic alumino-silicates from the dissolving biogenic opal. Using a numerical transport-reaction model we find that approximately 24% of the dissolving biogenic opal is re-precipitated in the sediments in the form of these authigenic phases at a relatively low precipitation rate of 56 μmol Si cm-2 yr-1. The fractionation factor between the precipitates and the pore waters is estimated at -2.0‰. Dissolved and solid cation concentrations further indicate that off Peru, where biogenic opal concentrations in the sediments are high, the availability of reactive terrigenous material is the limiting factor for the formation of authigenic alumino-silicate phases.

  13. Airborne flux measurements of Biogenic Isoprene over California

    Energy Technology Data Exchange (ETDEWEB)

    Misztal, P.; Karl, Thomas G.; Weber, Robin; Jonsson, H. H.; Guenther, Alex B.; Goldstein, Allen H.

    2014-10-10

    Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK+MAC, methanol, monoterpenes, and MBO over ~10,000-km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT) approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT) approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z/zi). Fluxes were generally measured by flying consistently 1 at 400 m ±50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF) landcover datasets used to drive biogenic VOC (BVOC) emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m-2 h-1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions, shrublands, and

  14. Airborne flux measurements of biogenic volatile organic compounds over California

    Directory of Open Access Journals (Sweden)

    P. K. Misztal

    2014-03-01

    Full Text Available Biogenic Volatile Organic Compound (BVOC fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi. Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l. altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF landcover datasets used to drive biogenic VOC (BVOC emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m−2 h−1 above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions

  15. Airborne observations of vegetation and implications for biogenic emission characterization.

    Science.gov (United States)

    Hawes, Amy K; Solomon, Susan; Portmann, Robert W; Daniel, John S; Langford, Andrew O; Miller, H LeRoy; Eubank, Charles S; Goldan, Paul; Wiedinmyer, Christine; Atlas, Elliot; Hansel, Armin; Wisthaler, Armin

    2003-12-01

    Measuring hydrocarbons from aircraft represents one way to infer biogenic emissions at the surface. The focus of this paper is to show that complementary remote sensing information can be provided by optical measurements of a vegetation index, which is readily measured with high temporal coverage using reflectance data. We examine the similarities between the vegetation index and in situ measurements of the chemicals isoprene, methacrolein, and alpha-pinene to estimate whether the temporal behavior of the in situ measurements of these chemicals could be better understood by the addition of the vegetation index. Data were compared for flights conducted around Houston in August and September 2000. The three independent sets of chemical measurements examined correspond reasonably well with the vegetation index curves for the majority of flight days. While low values of the vegetation index always correspond to low values of the in situ chemical measurements, high values of the index correspond to both high and low values of the chemical measurements. In this sense it represents an upper limit when compared with in situ data (assuming the calibration constant is adequately chosen). This result suggests that while the vegetation index cannot represent a purely predictive quantity for the in situ measurements, it represents a complementary measurement that can be useful in understanding comparisons of various in situ observations, particularly when these observations occur with relatively low temporal frequency. In situ isoprene measurements and the vegetation index were also compared to an isoprene emission inventory to provide additional insight on broad issues relating to the use of vegetation indices in emission database development.

  16. Biogenic carbon fluxes from global agricultural production and consumption

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Julie; West, Tristram O.; Le Page, Yannick LB; Kyle, G. Page; Zhang, Xuesong; Collatz, George; Imhoff, Marc L.

    2015-10-01

    Quantification of biogenic carbon fluxes from agricultural lands is needed to generate comprehensive bottom-up estimates of net carbon exchange for global and regional carbon monitoring. We estimated global agricultural carbon fluxes associated with annual crop net primary production (NPP), harvested biomass, and consumption of biomass by humans and livestock. These estimates were combined for a single estimate of net carbon exchange (NCE) and spatially distributed to 0.05 degree resolution using MODIS satellite land cover data. Global crop NPP in 2011 was estimated at 5.25 ± 0.46 Pg C yr-1, of which 2.05 ± 0.05 Pg C yr-1 was harvested and 0.54 Pg C yr-1 was collected from crop residues for livestock fodder. Total livestock feed intake in 2011 was 2.42 ± 0.21 Pg C yr-1, of which 2.31 ± 0.21 Pg C yr-1 was emitted as CO2, 0.07 ± 0.01 Pg C yr-1 was emitted as CH4, and 0.04 Pg C yr-1 was contained within milk and egg production. Livestock grazed an estimated 1.27 Pg C yr-1 in 2011, which constituted 52.4% of total feed intake. Global human food intake was 0.57 ± 0.03 Pg C yr-1 in 2011, the majority of which is respired as CO2. Completed global cropland carbon budgets accounted for the ultimate use of ca. 80% of harvested biomass. The spatial distribution of these fluxes may be used for global carbon monitoring, estimation of regional uncertainty, and for use as input to Earth system models.

  17. Biogenic silver nanoparticles: efficient and effective antifungal agents

    Science.gov (United States)

    Netala, Vasudeva Reddy; Kotakadi, Venkata Subbaiah; Domdi, Latha; Gaddam, Susmila Aparna; Bobbu, Pushpalatha; Venkata, Sucharitha K.; Ghosh, Sukhendu Bikash; Tartte, Vijaya

    2016-04-01

    Biogenic synthesis of silver nanoparticles (AgNPs) by exploiting various plant materials is an emerging field and considered green nanotechnology as it involves simple, cost effective and ecofriendly procedure. In the present study AgNPs were successfully synthesized using aqueous callus extract of Gymnema sylvestre. The aqueous callus extract treated with 1nM silver nitrate solution resulted in the formation of AgNPs and the surface plasmon resonance (SPR) of the formed AgNPs showed a peak at 437 nm in the UV Visible spectrum. The synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and X-ray diffraction spectroscopy (XRD). FTIR spectra showed the peaks at 3333, 2928, 2361, 1600, 1357 and 1028 cm-1 which revealed the role of different functional groups possibly involved in the synthesis and stabilization of AgNPs. TEM micrograph clearly revealed the size of the AgNPs to be in the range of 3-30 nm with spherical shape and poly-dispersed nature; it is further confirmed by Particle size analysis that the stability of AgNPs is due its high negative Zeta potential (-36.1 mV). XRD pattern revealed the crystal nature of the AgNPs by showing the braggs peaks corresponding to (111), (200), (220) and (311) planes of face-centered cubic crystal phase of silver. Selected area electron diffraction pattern showed diffraction rings and confirmed the crystalline nature of synthesized AgNPs. The synthesized AgNPs exhibited effective antifungal activity against Candida albicans, Candida nonalbicans and Candida tropicalis.

  18. Hyperspectral observation of anthropogenic and biogenic pollution in coastal zone

    Science.gov (United States)

    Lavrova, Olga; Loupian, Evgeny; Mityagina, Marina; Uvarov, Ivan

    The work presents results of anthropogenic and biogenic pollution detection in coastal zones of the Black and Caspian Seas based on satellite hyperspetral data provided by the Hyperion and HICO instruments. Techniques developed on the basis of the analysis of spectral characteristics calculated in special points were employed to address the following problems: (a) assessment of the blooming intensity of cyanobacteria and their distribution in bays of western Crimea and discrimination between anthropogenic pollutant discharge events and algae bloom; (b) detection of anthropogenic pollution in Crimean lakes utilized as industrial liquid discharge reservoirs; (c) detection of oil pollution in areas of shelf oil production in the Caspian Sea. Information values of different spectral bands and their composites were estimated in connection with the retrieval of the main sea water components: phytoplankton, suspended matter and colored organic matter, and also various anthropogenic pollutants, including oil. Software tools for thematic hyperspectral data processing in application to the investigation of sea coastal zones and internal water bodies were developed on the basis of the See the Sea geoportal created by the Space Research Institute RAS. The geoportal is focused on the study of processes in the world ocean with the emphasis on the advantages of satellite systems of observation. The tools that were introduced into the portal allow joint analysis of quasi-simultaneous satellite data, in particular data from the Hyperion, HICO, OLI Landsat-8, ETM Landsat-7 and TM Landsat-5 instruments. Results of analysis attempts combining data from different sensors are discussed. Their strong and weak points are highlighted. The study was completed with partial financial support from The Russian Foundation for Basic Research grants # 14-05-00520-a and 13-07-12017.

  19. Reversible and irreversible processing of biogenic olefins on acidic aerosols

    Directory of Open Access Journals (Sweden)

    J. Liggio

    2008-04-01

    Full Text Available Recent evidence has suggested that heterogeneous chemistry of oxygenated hydrocarbons, primarily carbonyls, plays a role in the formation of secondary organic aerosol (SOA; however, evidence is emerging that direct uptake of alkenes on acidic aerosols does occur and can contribute to SOA formation. In the present study, significant uptake of monoterpenes, oxygenated monoterpenes and sesquiterpenes to acidic sulfate aerosols is found under various conditions in a reaction chamber. Proton transfer mass spectrometry is used to quantify the organic gases, while an aerosol mass spectrometer is used to quantify the organic mass uptake and obtain structural information for heterogeneous products. Aerosol mass spectra are consistent with several mechanisms including acid catalyzed olefin hydration, cationic polymerization and organic ether formation, while measurable decreases in the sulfate mass on a per particle basis suggest that the formation of organosulfate compounds is also likely. A portion of the heterogeneous reactions appears to be reversible, consistent with reversible olefin hydration reactions. A slow increase in the organic mass after a fast initial uptake is attributed to irreversible reactions, consistent with polymerization and organosulfate formation. Uptake coefficients (γ were estimated for a fast initial uptake governed by the mass accommodation coefficient (α and ranged from 1×10-6-2.5×10-2. Uptake coefficients for a subsequent slower reactive uptake ranged from 1×10-7-1×10-4. These processes may potentially lead to a considerable amount of SOA from the various biogenic hydrocarbons under acidic conditions, which can be highly significant for freshly nucleated aerosols, particularly given the large array of atmospheric olefins.

  20. Reversible and irreversible processing of biogenic olefins on acidic aerosols

    Science.gov (United States)

    Liggio, J.; Li, S.-M.

    2008-04-01

    Recent evidence has suggested that heterogeneous chemistry of oxygenated hydrocarbons, primarily carbonyls, plays a role in the formation of secondary organic aerosol (SOA); however, evidence is emerging that direct uptake of alkenes on acidic aerosols does occur and can contribute to SOA formation. In the present study, significant uptake of monoterpenes, oxygenated monoterpenes and sesquiterpenes to acidic sulfate aerosols is found under various conditions in a reaction chamber. Proton transfer mass spectrometry is used to quantify the organic gases, while an aerosol mass spectrometer is used to quantify the organic mass uptake and obtain structural information for heterogeneous products. Aerosol mass spectra are consistent with several mechanisms including acid catalyzed olefin hydration, cationic polymerization and organic ether formation, while measurable decreases in the sulfate mass on a per particle basis suggest that the formation of organosulfate compounds is also likely. A portion of the heterogeneous reactions appears to be reversible, consistent with reversible olefin hydration reactions. A slow increase in the organic mass after a fast initial uptake is attributed to irreversible reactions, consistent with polymerization and organosulfate formation. Uptake coefficients (γ) were estimated for a fast initial uptake governed by the mass accommodation coefficient (α) and ranged from 1×10-6-2.5×10-2. Uptake coefficients for a subsequent slower reactive uptake ranged from 1×10-7-1×10-4. These processes may potentially lead to a considerable amount of SOA from the various biogenic hydrocarbons under acidic conditions, which can be highly significant for freshly nucleated aerosols, particularly given the large array of atmospheric olefins.

  1. Biogenicity of an Early Quaternary iron formation, Milos Island, Greece.

    Science.gov (United States)

    Chi Fru, E; Ivarsson, M; Kilias, S P; Frings, P J; Hemmingsson, C; Broman, C; Bengtson, S; Chatzitheodoridis, E

    2015-05-01

    A ~2.0-million-year-old shallow-submarine sedimentary deposit on Milos Island, Greece, harbours an unmetamorphosed fossiliferous iron formation (IF) comparable to Precambrian banded iron formations (BIFs). This Milos IF holds the potential to provide clues to the origin of Precambrian BIFs, relative to biotic and abiotic processes. Here, we combine field stratigraphic observations, stable isotopes of C, S and Si, rock petrography and microfossil evidence from a ~5-m-thick outcrop to track potential biogeochemical processes that may have contributed to the formation of the BIF-type rocks and the abrupt transition to an overlying conglomerate-hosted IF (CIF). Bulk δ(13) C isotopic compositions lower than -25‰ provide evidence for biological contribution by the Calvin and reductive acetyl-CoA carbon fixation cycles to the origin of both the BIF-type and CIF strata. Low S levels of ~0.04 wt.% combined with δ(34) S estimates of up to ~18‰ point to a non-sulphidic depository. Positive δ(30) Si records of up to +0.53‰ in the finely laminated BIF-type rocks indicate chemical deposition on the seafloor during weak periods of arc magmatism. Negative δ(30) Si data are consistent with geological observations suggesting a sudden change to intense arc volcanism potentially terminated the deposition of the BIF-type layer. The typical Precambrian rhythmic rocks of alternating Fe- and Si-rich bands are associated with abundant and spatially distinct microbial fossil assemblages. Together with previously proposed anoxygenic photoferrotrophic iron cycling and low sedimentary N and C potentially connected to diagenetic denitrification, the Milos IF is a biogenic submarine volcano-sedimentary IF showing depositional conditions analogous to Archaean Algoma-type BIFs.

  2. The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

    Science.gov (United States)

    Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

    2015-04-01

    late compressive strength, the worst performing cement was the one with the lowest reactive silica content with biogenic opal-A as the only reactive pozzolana constituent. Cements produced with perlites, raw materials consisting mainly of a glassy phase, were characterized by higher strength and a rather ordinary specific surface area. Cements produced with Turkish zeolite tuff and Milos glassy tuff exhibited higher late compressive strength than those mentioned above. The highest strength was achieved by the implementation of Australian diatomite for cement production. Its 28 day strength exceeded that of the control mixture consisting of 95% clinker and 5% gypsum. That could be attributed to both, high specific surface of cement and reactive SiO2 of diatomite. Therefore, a preliminary assessment regarding late strength of pozzolanic cements could be obtained by the consideration of two main parameters, namely: specific surface area of cement and reactive silica content of pozzolana.

  3. Mineralization of Bacteria in Terrestrial Basaltic Rocks: Comparison With Possible Biogenic Features in Martian Meteorite Allan Hills 84001

    Science.gov (United States)

    Thomas-Keprta, K. L.; McKay, D. S.; Wentworth, S. J.; Stevens, T. O.; Taunton, A. E.; Allen, C. C.; Gibson, E. K., Jr.; Romanek, C. S.

    1998-01-01

    The identification of biogenic features altered by diagenesis or mineralization is important in determining whether specific features in terrestrial rocks and in meteorites may have a biogenic origin. Unfortunately, few studies have addressed the formation of biogenic features in igneous rocks, which may be important to these phenomena, including the controversy over possible biogenic features in basaltic martian meteorite ALH84001. To explore the presence of biogenic features in igneous rocks, we examined microcosms growing in basaltic small-scale experimental growth chambers or microcosms. Microbial communities were harvested from aquifers of the Columbia River Basalt (CRB) group and grown in a microcosm containing unweathered basalt chips and groundwater (technique described in. These microcosms simulated natural growth conditions in the deep subsurface of the CRB, which should be a good terrestrial analog for any putative martian subsurface ecosystem that may have once included ALH84001. Here we present new size measurements and photomicrographs comparing the putative martian fossils to biogenic material in the CRB microcosms. The range of size and shapes of the biogenic features on the CRB microcosm chips overlaps with and is similar to those on ALH84001 chips. Although this present work does not provide evidence for the biogenicity of ALH84001 features, we believe that, based on criteria of size, shape, and general morphology, a biogenic interpretation for the ALH84001 features remains plausible.

  4. The impact of biogenic VOC emissions on photochemical ozone formation during a high ozone pollution episode in the Iberian Peninsula in the 2003 summer season

    Directory of Open Access Journals (Sweden)

    N. Castell

    2008-04-01

    Full Text Available Throughout Europe the summer of 2003 was exceptionally warm, especially July and August. The European Environment Agency (EEA reported several ozone episodes, mainly in the first half of August. These episodes were exceptionally long-lasting, spatially extensive, and associated to high temperatures. In this paper, the 10$ndash;15 August 2003 ozone pollution event has been analyzed using meteorological and regional air quality modelling. During this period the threshold values of the European Directive 2002/3/EC were exceeded in various areas of the Iberian Peninsula.

    The aim of this paper is to computationally understand and quantify the influence of biogenic volatile organic compound (BVOC emissions in the formation of tropospheric ozone during this high ozone episode. Being able to differentiate how much ozone comes from biogenic emissions alone and how much comes from the interaction between anthropogenic and biogenic emissions would be helpful to develop a feasible and effective ozone control strategy. The impact on ozone formation was also studied in combination with various anthropogenic emission reduction strategies, i.e., when anthropogenic VOC emissions and/or NOx emissions are reduced. The results show a great dependency of the BVOC contribution to ozone formation on the antropoghenic reduction scenario. In rural areas, the impact due to a NOx and/or VOC reduction does not change the BVOC impact. Nevertheless, within big cities or industrial zones, a NOx reduction results in a decrease of the biogenic impact in ozone levels that can reach 85 μg/m3, whereas an Anthropogenic Volatile Organic Compound (AVOC reduction results in a decrease of the BVOC contribution on ozone formation that varies from 0 to 30 μg/m3 with respect to the contribution at the same points in the 2003 base scenario. On the other hand, downwind of the big cities, a decrease in NOx produces

  5. Biogenic amines in food and their determination methods%食品中的生物胺及其检测方法

    Institute of Scientific and Technical Information of China (English)

    王颖; 邱璠; 韩北忠; 殷丽君

    2011-01-01

    生物胺普遍存在于生物体中,有重要的生理功能.许多天然食品中都含有生物胺.摄入大量生物胺会引起身体不适,严重的还可能危及生命.引起食物中毒的生物胺主要包括组胺和酪胺.此外,存在大量微生物的食品中,生物胺的含量较高,同类食品中生物胺的种类和含量又有很大的变化,这一现象受许多因素影响,如微生物的种类和数量、温度、pH值等.生物胺含量还与食品的腐败变质有关,是食品品质的指示器,因此对于生物胺的检测受到重视.目前检测食品中生物胺含量的方法主要有薄层色谱、气相色谱、毛细管电泳和高效液相色谱.%Biogenic amines (BA) which commonly present in living organisms play important roles in essential functions. Many natural foods contain biogenic amines. Biogenic amines can be produced by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern, even life-threatening. Histamine and tyramine are the main amines which are causative agents in food poisoning episodes. In addition, high microbial counts often lead to considerable accumulation of biogenic amines. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the composition of microflora, temperature, pH value, and so on. Biogenic amines are indicators of spoilage of food and the analytical methods used for quanti?cation of BA are mainly based on chromato-graphic methods: thin layer chromatography, gas chromatography, capillary electrophoresis and high-performance liquid chromatography.

  6. Piezo-tolerant natural gas-producing microbes under accumulating pCO2

    NARCIS (Netherlands)

    Lindeboom, Ralph E.F.; Shin, Seung Gu; Weijma, Jan; Lier, van Jules B.; Plugge, Caroline M.

    2016-01-01


    Background

    It is known that a part of natural gas is produced by biogenic degradation of organic matter, but the microbial pathways resulting in the formation of pressurized gas fields remain unknown. Autogeneration of biogas pressure of up to 20 bar has been shown to improve the quali

  7. Integration of biogenic emissions in environmental fate, transport, and exposure systems

    Science.gov (United States)

    Efstathiou, Christos I.

    Biogenic emissions make a significant contribution to the levels of aeroallergens and secondary air pollutants such as ozone. Understanding major factors contributing to allergic airway diseases requires accurate characterization of emissions and transport/transformation of biogenic emissions. However, biogenic emission estimates are laden with large uncertainties. Furthermore, the current biogenic emission estimation models use low-resolution data for estimating land use, vegetation biomass and VOC emissions. Furthermore, there are currently no established methods for estimating bioaerosol emissions over continental or regional scale, which can impact the ambient levels of pollent that have synergestic effects with other gaseous pollutants. In the first part of the thesis, an detailed review of different approaches and available databases for estimating biogenic emissions was conducted, and multiple geodatabases and satellite imagery were used in a consistent manner to improve the estimates of biogenic emissions over the continental United States. These emissions represent more realistic, higher resolution estimates of biogenic emissions (including those of highly reactive species such as isoprene). The impact of these emissions on tropospheric ozone levels was studied at a regional scale through the application of the USEPA's Community Multiscale Air Quality (CMAQ) model. Minor, but significant differences in the levels of ambient ozone were observed. In the second part of the thesis, an algorithm for estimating emissions of pollen particles from major allergenic tree and plant families in the United States was developed, extending the approach for modeling biogenic gas emissions in the Biogenic Emission Inventory System (BEIS). A spatio-temporal vegetation map was constructed from different remote sensing sources and local surveys, and was coupled with a meteorological model to develop pollen emissions rates. This model overcomes limitations posed by the lack of

  8. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2012-10-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus, were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources.

    The biogenic factor was strongly correlated (r ~ 0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp < 100 nm (r~ 0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r ~ 0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with

  9. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2013-03-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign, when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July, the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs, and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r~0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dpr~0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r~0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp>100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering the biogenic

  10. Safety assessment of the biogenic amines in fermented soya beans and fermented bean curd.

    Science.gov (United States)

    Yang, Juan; Ding, Xiaowen; Qin, Yingrui; Zeng, Yitao

    2014-08-06

    To evaluate the safety of biogenic amines, high performance liquid chromatography (HPLC) was used to evaluate the levels of biogenic amines in fermented soya beans and fermented bean curd. In fermented soya beans, the total biogenic amines content was in a relatively safe range in many samples, although the concentration of histamine, tyramine, and β-phenethylamine was high enough in some samples to cause a possible safety threat, and 8 of the 30 samples were deemed unsafe. In fermented bean curd, the total biogenic amines content was more than 900 mg/kg in 19 white sufu amples, a level that has been determined to pose a safety hazard; putrescine was the only one detected in all samples and also had the highest concentration, which made samples a safety hazard; the content of tryptamine, β-phenethylamine, tyramine, and histamine had reached the level of threat to human health in some white and green sufu samples, and that may imply another potential safety risk; and 25 of the 33 samples were unsafe. In conclusion, the content of biogenic amines in all fermented soya bean products should be studied and appropriate limits determined to ensure the safety of eating these foods.

  11. Oligocene biogenic siliceous deposits on the slope of the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The abundance of radiolarian, diatom and sponge spicule and H4SiO4 in pore-waters increase abruptly at the boundary between Early and Late Oligocene (about 30-27.5 Ma) at Site 1148 of the northern South China Sea (SCS), indicating high biogenic silica accumulation during this time. At the same time (about 30-28 Ma), high biogenic silica deposition occurred in the cen tral equatorial Pacific. Comparison of the biogenic silica accumulation at Site 1148 of the SCS with that at Site 929 of the Atlantic verifies that the biogenic silica accumulation between the low lati tude Pacific and Atlantic oceans expresses the evident relationship of compensation during theOligocene. Biogenic silica accumulation decreased in the Atlantic, whereas it increased in the Pa cific at the boundary between the Early and Late Oligocene. It resulted from the formation and presence of North Atlantic deep water (NADW) in the Atlantic basin, indicating an intensive basin-basin fractionation. XRD analysis and SEM observation of the samples from Site 1148 demon strate that most of radiolarian, diatom and sponge spicule have suffered from dissolution and reprecipitation, suggested by the opal-A→opal-CT transformation. As a result of the transformation,porosity increased, but dry and bulk densities decreased, reflecting the consequence of diagenesis on the physical property of sediment.

  12. Cocaine affects foraging behaviour and biogenic amine modulated behavioural reflexes in honey bees

    Directory of Open Access Journals (Sweden)

    Eirik Søvik

    2014-11-01

    Full Text Available In humans and other mammals, drugs of abuse alter the function of biogenic amine pathways in the brain leading to the subjective experience of reward and euphoria. Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear. Previously, it has been shown that bees are more likely to dance (a signal of perceived reward when returning from a sucrose feeder after cocaine treatment. Here we examined more broadly whether cocaine altered reward-related behaviour, and biogenic amine modulated behavioural responses in bees. Bees developed a preference for locations at which they received cocaine, and when foraging at low quality sucrose feeders increase their foraging rate in response to cocaine treatment. Cocaine also increased reflexive proboscis extension to sucrose, and sting extension to electric shock. Both of these simple reflexes are modulated by biogenic amines. This shows that systemic cocaine treatment alters behavioural responses that are modulated by biogenic amines in insects. Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees. We discuss the implications of these results for understanding the ecology of cocaine as a plant defence compound. Our findings further validate the honey bee as a model system for understanding the behavioural impacts of cocaine, and potentially other drugs of abuse.

  13. BIOGENIC AMINES CONTENT IN SELECTED COMMERCIAL FERMENTED PRODUCTS OF ANIMAL ORIGIN

    Directory of Open Access Journals (Sweden)

    Vendula Pachlová

    2012-08-01

    Full Text Available The aim of this study was to monitor of biogenic amines contents in commercial fermented products, especially various type of ripening cheeses and fermented meat products (15 cheese samples and nine dry fermented meat products obtained from Czech Republic, Slovak Republic, Poland, and Germany. Furthermore, the changes in samples during storage were also observed. The samples were stored at 6±1°C. The samples were taken the first day of storage and the last day of shelf-life. The biogenic amines content was determined using ion-exchange liquid chromatography with post-column derivatization and photometric detection. The content of biogenic amines increased during storage. The highest biogenic amines content at the end of storage was observed in Dutch-type cheeses and in Smear cheeses, in both the concentrations exceeded 1 000 mg.kg-1. Latter mentioned amount may have serious negative impact on consumer health. The lowest concentration of biogenic amines was detected in Blue cheese.

  14. Sensitivity of global biogenic isoprenoid emissions to climate variability and atmospheric CO2

    Science.gov (United States)

    Naik, Vaishali; Delire, Christine; Wuebbles, Donald J.

    2004-03-01

    Isoprenoids (isoprene and monoterpenes) are the most dominant class of biogenic volatile organic compounds (BVOCs) and have been shown to significantly affect global tropospheric chemistry and composition, climate, and the global carbon cycle. In this study we assess the sensitivity of biogenic isoprene and monoterpene emissions to combined and isolated fluctuations in observed global climate and atmospheric carbon dioxide (CO2) concentration during the period 1971-1990. We integrate surface emission algorithms within the framework of a dynamic global ecosystem model, the Integrated Biospheric Simulator (IBIS), to simulate biogenic fluxes of isoprenoids as a component of the climate-vegetation dynamics. IBIS predicts global land surface isoprene emissions of 454 Tg C and monoterpenes of 72 Tg C annually and captures the spatial and temporal patterns well. The combined fluctuations in climate and atmospheric CO2 during 1971-1990 caused significant interannual and seasonal variability in global biogenic isoprenoid fluxes that was somewhat related to the El Niño-Southern Oscillation. Furthermore, an increasing trend in the simulated emissions was seen during this period that is attributed partly to the warming trend and partly to CO2 fertilization effect. The isolated effect of increasing CO2 during this period was to steadily increase emissions as a result of increases in foliar biomass. These fluctuations in biogenic emissions could have significant impacts on regional and global atmospheric chemistry and the global carbon budget.

  15. Colloidal properties of nanoparticular biogenic selenium govern environmental fate and bioremediation effectiveness.

    Science.gov (United States)

    Buchs, Benjamin; Evangelou, Michael W H; Winkel, Lenny H E; Lenz, Markus

    2013-03-05

    Microbial selenium (Se) bioremediation is based on conversion of water soluble, toxic Se oxyanions to water insoluble, elemental Se. Formed biogenic elemental Se is of nanometer size, hampering straightforward separation from the aqueous phase. This study represents the first systematic investigation on colloidal properties of pure biogenic Se suspensions, linking electrophoretic mobility (ζ-potential) to column settling behavior. It was demonstrated that circumneutral pH, commonly applied in bioremediation, is not appropriate for gravitational separation due to the negative ζ-potential preventing agglomeration. Mono/di/trivalent counter cations and acidity (protons) were used to screen efficiently the intrinsic negative charge of biogenic Se suspensions at circumneutral pH. Fast settling was induced by La(3+) addition in the micromolar range (86.2 ± 3.5% within 0.5 h), whereas considerably higher concentrations were needed when Ca(2+) or Na(+) was used. Colloidal stability was furthermore studied in different model waters. It was demonstrated that surface waters as such represent a fragile system regarding colloidal stability of biogenic Se suspensions (ζ-potential ∼ -30 mV), whereas dissolved organic matter increases colloidal stability. In marine waters, biogenic Se is colloidally destabilized and is thus expected to settle, representing a potential sink for Se during transport in the aquatic environment.

  16. The Effects of Drought on Predictions of Air Quality in Texas: Vegetation and Biogenic Hydrocarbons

    Science.gov (United States)

    McDonald-Buller, E.; Huang, L.; McGaughey, G.; Kimura, Y.; Allen, D.

    2014-12-01

    Biogenic hydrocarbons, primarily isoprene and monoterpenes, are important precursors for tropospheric ozone and secondary organic aerosol formation. Annual biogenic emissions in Texas ranked first within the continental United States in the 2011 National Emission Inventory. In recent years, the effects of drought in Texas have been among the most severe in the southern United States; during 2011, more than 80% of the state was under exceptional drought. Understanding the effects of drought on vegetation and biogenic emissions is important as the state concurrently faces requirements to achieve and maintain attainment with the National Ambient Air Quality Standard (NAAQS) for ozone in several large metropolitan areas. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) has been utilized extensively for the estimation of biogenic emissions on global and regional scales. This research investigates the interannual variability in leaf area index and isoprene and monoterpene emissions estimates from MEGAN in eastern Texas climate regions with diverse climatology and land cover. In MEGAN, the adjustment to emissions from a standardized set of environmental conditions is determined using a multiplication of individual activity factors for leaf age, soil moisture, and the canopy environment. The research also interprets and quantifies differences in environmental activity factors between years with extreme to exceptional drought and average to above average precipitation in eastern Texas and identifies influences on biogenic emissions estimates from MEGAN.

  17. Biogenic amines in table olives. Analysis by high-performance liquid chromatography.

    Science.gov (United States)

    Hornero-Méndez, D; Garrido-Fernández, A

    1994-09-01

    Biogenic amines in fermented vegetables have scarcely been studied. Available data show that in table olives and fermented cucumbers their presence is rare and any determinations made have been restricted mainly to histamine. However, some microorganisms, especially those related to spoilage, found in the fermentation brines of such products may have amino acid decarboxylase activity and give rise to biogenic amines by unusual processes. A method for the simultaneous determination of eight biogenic amines (tryptamine, beta-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) has been developed to study their occurrence in fermented vegetables in more detail. The method consists of extraction of the amines from olive paste with 5% m/v trichloracetic acid and successive transfers into water-saturated n-BuOH and 0.1 mol l-1 HCl. An aliquot of this mixture is dried and derivatized with dansyl chloride. The dansyl derivatives are then analysed by high-performance liquid chromatography. Special emphasis has been given to optimization of the n-BuOH and 0.1 mol l-1 HCl extractions and to the derivatization conditions. By applying this method to the analysis of spoilt olives, the presence of some biogenic amines has been demonstrated. Thus a new method for monitoring the presence of biogenic amines during the fermentation of olives and for detecting anomalous fermentations is envisaged.

  18. Recent trends in the determination of biogenic amines in fermented beverages - A review.

    Science.gov (United States)

    Ordóñez, José Luis; Troncoso, Ana Maria; García-Parrilla, Maria Del Carmen; Callejón, Raquel Maria

    2016-10-05

    Biogenic amines (BA) are generally considered as a food hazard, even though there is not a threshold for these biomolecules in the European legislation, except for histamine in fishery products. These compounds are formed during the storage and processing of certain foods through microbiological activity, and when present in high concentrations, could have toxicological effects, causing health problems in consumers, especially to sensitive persons. This fact, in addition to the economical concern involved, makes it necessary to control the amounts of biogenic amines in foods. For all these reasons, literature on biogenic amines in different food products, especially in fermented beverages, is extensive. This review provides an overview of the most recent trends in the determination of biogenic amines in fermented beverages focusing on novelty, improvement and optimization of analytical methods. Hence, the different sample treatment procedures (including derivatization), the most important analytical techniques and the most frequent applications are described and discussed. Although biogenic amines have been determined in wine and other fermented beverages for decades, new advancements and technical possibilities have allowed to increase the accuracy and sensitivity of analytical methods, in order to overcome the challenges posed by the complex matrices and their high intrinsic variability. Thus, the different purposes of BA determination (food safety, production process or food microbiology research) and the most widely employed analytical techniques have been reviewed.

  19. The Deep-Sea Natural Products, Biogenic Polyphosphate (Bio-PolyP and Biogenic Silica (Bio-Silica, as Biomimetic Scaffolds for Bone Tissue Engineering: Fabrication of a Morphogenetically-Active Polymer

    Directory of Open Access Journals (Sweden)

    Florian Draenert

    2013-03-01

    Full Text Available Bone defects in human, caused by fractures/nonunions or trauma, gain increasing impact and have become a medical challenge in the present-day aging population. Frequently, those fractures require surgical intervention which ideally relies on autografts or suboptimally on allografts. Therefore, it is pressing and likewise challenging to develop bone substitution materials to heal bone defects. During the differentiation of osteoblasts from their mesenchymal progenitor/stem cells and of osteoclasts from their hemopoietic precursor cells, a lineage-specific release of growth factors and a trans-lineage homeostatic cross-talk via signaling molecules take place. Hence, the major hurdle is to fabricate a template that is functioning in a way mimicking the morphogenetic, inductive role(s of the native extracellular matrix. In the last few years, two naturally occurring polymers that are produced by deep-sea sponges, the biogenic polyphosphate (bio-polyP and biogenic silica (bio-silica have also been identified as promoting morphogenetic on both osteoblasts and osteoclasts. These polymers elicit cytokines that affect bone mineralization (hydroxyapatite formation. In this manner, bio-silica and bio-polyP cause an increased release of BMP-2, the key mediator activating the anabolic arm of the hydroxyapatite forming cells, and of RANKL. In addition, bio-polyP inhibits the progression of the pre-osteoclasts to functionally active osteoclasts. Based on these findings, new bioinspired strategies for the fabrication of bone biomimetic templates have been developed applying 3D-printing techniques. Finally, a strategy is outlined by which these two morphogenetically active polymers might be used to develop a novel functionally active polymer.

  20. Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean

    Directory of Open Access Journals (Sweden)

    P. J. Vidya

    2013-02-01

    Full Text Available Seasonal cycle of biogenic fluxes obtained from sediment trap at two locations 5° 24′ N, 86° 46′ E (SBBT and 3° 34′ N, 77° 46′ E (EIOT within the equatorial Indian Ocean (EIO were examined to understand the factors that control them. The sediment trap data at SBBT were collected for ten years from November 1987 while that at EIOT was for one year period from January 1996. The characteristic of biogenic flux at SBBT was the strong seasonality with peak flux in August, while lack of seasonality characterized the flux at EIOT. At the SBBT and EIOT, the higher chlorophyll biomass during summer monsoon was supported by wind-mixing, which supplied new nitrogen to the upper ocean. The stronger winds at SBBT compared to EIOT resulted in greater entrainment of nutrients to the euphotic zone, which supported higher chlorophyll biomass. High cell counts of phytoplankton (> 5 μm at SBBT dominated by diatoms suggest the operation of classical food web and high carbon export. On the contrary, one-and-half time higher magnitude of micro-zooplankton biomass dominated by picophytoplankton along with 2-fold lesser meso-zooplankton at EIOT indicated the importance of microbial loop. The substantial decrease in the carbon export at EIOT indicated faster remineralization of photosynthetically produced organic matter. We see a striking similarity between the biological process that operates in the SBBT with that of the equatorial Atlantic and EIOT with that of the equatorial Pacific, though the physical forcing in these three regions, namely EIO, the equatorial Atlantic and the equatorial Pacific, are very different.

  1. The biogenic emission potential of nitric oxide from sandy soils

    Science.gov (United States)

    Yu, J. B.; Meixner, F. X.; Sun, Z. G.; Chen, X. B.; Mamtimin, B.

    2009-04-01

    There are about 160.9 Mha of sandy land in China, about 17.6% of total Chinese area, which mainly distributed in 35°-50° N. The western Songnen Plain, which located in the semi-arid region of Northeastern China, is one of the main sandy soil distribution regions. The changes of land use in sandy soil are accompanied by changes in biogeochemical cycles of nutrients, particularly of the air-surface exchange of trace gases like nitric oxide. Our study, based on results obtained by a laboratory incubation technique, focuses on (a) NO production and consumption in sandy soils from two types of land use as function of soil temperature and soil moisture, and (b) The biogenic emission potential of nitric oxide from sandy soils in semi-arid region. At 25˚C, average NO production (in terms of mass of N) was 0.016,and 0.013 ng kg-1s-1 in sandy soils from soybean land (SL) and man-made forest (MF), re¬spectively. NO consumption rate constant ranged from 0.26×10-6 to 7.28×10-6 m3 kg-1s-1. At 25˚C and under optimum soil moisture conditions for NO production, the NO compensation point mixing ratio was about 266 and 161 ug m-3 (465,and 281 ppb) for soils of SL and MF, respectively. Statistically sound relationships have been observed between NO fluxes and soil moisture (optimum curves). NO fluxes also increased exponentially with soil temperature at any given soil moisture. The optimum soil moisture for which maximum NO flux was observed was independent of soil temperature. The maximum of NO flux potentials for SL and MF soils (at 25°C) were 59.6 and 36.5 ng m-2s-1 at water-filled pore space (%WFPS) of 26 and 24, respectively. The NO flux potential was about 2 times larger for cropland soil than for man-made forest soils, most likely due to fertilizer application to the cropland soils.

  2. A comparison between acoustic properties and heat effects in biogenic (magnetosomes) and abiotic magnetite nanoparticle suspensions

    Science.gov (United States)

    Józefczak, A.; Leszczyński, B.; Skumiel, A.; Hornowski, T.

    2016-06-01

    Magnetic nanoparticles show unique properties and find many applications because of the possibility to control their properties using magnetic field. Magnetic nanoparticles are usually synthesized chemically and modification of the particle surface is necessary. Another source of magnetic nanoparticles are various magnetotactic bacteria. These biogenic nanoparticles (magnetosomes) represent an attractive alternative to chemically synthesized iron oxide particles because of their unique characteristics and a high potential for biotechnological and biomedical applications. This work presents a comparison between acoustic properties of biogenic and abiotic magnetite nanoparticle suspensions. Experimental studies have shown the influence of a biological membrane on the ultrasound properties of magnetosomes suspension. Finally the heat effect in synthetic and biogenic magnetite nanoparticles is also discussed. The experimental study shows that magnetosomes present good heating efficiency.

  3. Geological and geochemical characteristics of the secondary biogenic gas in coalbed gases, Huainan coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Xiaojun, Zhang; Zhenglin, Cao; Mingxin, Tao; Wanchun, Wang; Jinlong, Ma

    2010-09-15

    The research results show that the compositions of coalbed gases in Huainan coalfield have high content methane, low content heavy hydrocarbons and carbon dioxide, and special dry gas. The evolution coal is at the stage of generation of thermogenic gases, but the d13C1 values within the range of biogenic gas (d13C1 values from -56.7{per_thousand} to -67.9{per_thousand}). The d13C2 value of coalbed gases in Huainan coalfield shows not only the features of the thermogenic ethane, but also the mixed features of the biogenic methane and thermogenic ethane. In geological characteristics, Huainan coalfield has favorable conditions of generation of secondary biogenic gas.

  4. Evaluation of larvicidal activity of biogenic nanoparticles against filariasis causing Culex mosquito vector

    Science.gov (United States)

    Dhanasekaran, Dharumadurai; Thangaraj, Ramasamy

    2013-01-01

    Objective To evaluate the larvicidal activity of biogenic nanoparticles against filariasis causing Culex mosquito vector. Methods The synthesized AgNPs were characterized by UV-vis. spectrum, Fourier transform infrared and X-ray diffraction. Larvae were exposed to varying concentrations of aqueous extract of synthesized AgNPs for 10 min. The different concentrations of 5, 2.5, 1.25, 0.625 and 0.312 mg/L silver nanoparticles were tested against the Culex larvae. Results The mortality rate of Agaricus bisporus biogenic nanoparticles against Culex larvae are 5 mg/L (100%), 2.5 mg/L (81%), 1.25 mg/L (62%), 0.625 mg/L (28%) and 0.312 mg/L (11%). Conclusions These results suggest that the synthesized biogenic AgNPs have the potential to be used as an ideal eco-friendly approach for controlling Culex larvae.

  5. Carbonyl sulfide as an inverse tracer for biogenic organic carbon in gas and aerosol phases

    Science.gov (United States)

    de Gouw, J. A.; Warneke, C.; Montzka, S. A.; Holloway, J. S.; Parrish, D. D.; Fehsenfeld, F. C.; Atlas, E. L.; Weber, R. J.; Flocke, F. M.

    2009-03-01

    Carbonyl sulfide (COS) is a long-lived trace gas in the atmosphere with an oceanic source and a surface sink through the uptake by vegetation and soils. We demonstrate the use of COS as an inverse tracer for the impact of biogenic emissions on an air mass including the formation of secondary organic aerosol (SOA). Using airborne data from the summer of 2004 over the northeastern U.S., we find that air masses with reduced COS in the continental boundary layer had on average higher mixing ratios of biogenic VOCs (isoprene, monoterpenes, methanol) and their photo-oxidation products (methacrolein, methyl vinyl ketone, methyl furan and MPAN, a peroxyacyl nitrate derived from isoprene). Measurements of water-soluble organic carbon were only weakly correlated with COS, indicating that SOA formation from biogenic precursors was a small contribution to the total.

  6. Altervalent substitution of sodium for calcium in biogenic calcite and aragonite

    Science.gov (United States)

    Yoshimura, Toshihiro; Tamenori, Yusuke; Suzuki, Atsushi; Kawahata, Hodaka; Iwasaki, Nozomu; Hasegawa, Hiroshi; Nguyen, Luan T.; Kuroyanagi, Azumi; Yamazaki, Toshitsugu; Kuroda, Junichiro; Ohkouchi, Naohiko

    2017-04-01

    Sodium concentrations in biogenic CaCO3 are several thousands of parts per million, and, on a molar basis, Na is among the most abundant constituent minor element in these carbonates. Nevertheless, the chemical form of Na in CaCO3 is not well constrained. We used synchrotron X-ray spectroscopy to identify the dominant molecular host sites for Na in biogenic calcite and aragonite precipitated by corals, bivalves, and foraminifera. We also used the K-edge X-ray absorption near-edge structure to investigate the chemical environment of Na in biogenic calcium carbonates and identify the altervalent substitution of Na into Ca sites in the lattice structures of calcite and aragonite. Minor cation and anion concentrations in biogenic CaCO3 suggest that the principal substitution mechanism involves charge compensation through the creation of CO32- vacancies. The mostly homogeneous Na concentrations in the skeletal microstructures of the various biota we examined indicate that environmental and biological controls, such as temperature, skeletal microstructure, and calcification rates, have only minor influences on skeletal Na concentrations. A decrease of Na:Ca ratios with increasing age of foraminiferal shells picked from a Quaternary sediment core, indicates progressive release of Na, which suggests that structurally-substituted Na in biogenic CaCO3 is readily leached during burial diagenesis. Whereas the sediment that undergo diagenesis release some Na back to the water column, sodium co-precipitation in biogenic CaCO3 serves as a potential sink of Na for the ocean.

  7. Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments.

    Science.gov (United States)

    Durán, Nelson; Nakazato, Gerson; Seabra, Amedea B

    2016-08-01

    The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations (Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols.

  8. Experimental assessment of the liquefaction resistance of calcareous biogenous sands

    Directory of Open Access Journals (Sweden)

    Sandoval Eimar

    2012-10-01

    Full Text Available

    ABSTRACT

    Liquefaction is a phenomenon in which soils, typically sands, suddenly loose a substantial amount of their shear strength and stiffness, this often triggered by large-magnitude earthquakes. Most liquefaction research has focused on silicate-based sands and not on other sand types, such as calcareous biogenous sands Calcareous sands are usually composed of skeletal or non-skeletal remains of marine organisms, with unique characteristics in terms of their mineralogy surface roughness, particle shape, crushability, and intraparticle porosity. The unique characteristics of calcareous sands suggest that their geotechnical engineering behaviour can be substantially different compared to that of terrigenous sands, including their behaviour under seismic loading, which have not been very well studied

    This paper presents the results of an experimental programme aimed at studying the cyclic liquefaction resistance of uncemented calcareous biogenous sands retrieved from south-western Puerto Rico Evaluation of liquefaction potential involved a comprehensive set of isotropically consolidated undrained cyclic triaxial tests on reconstituted samples of this calcareous sand. The programme also included tests on Ottawa terrigenous silica sand samples prepared and tested in similar conditions for comparison purposes.

    In general, the experimental results showed that Cabo Rojo calcareous sands had higher liquefaction resistance compared to Ottawa silica sands tested under similar conditions. Important differences between calcareous and silica sands regarding pore pressure generation characteristics and axial strain accumulation were also observed


  9. Biogenic amine content, histamine-forming bacteria, and adulteration of pork in tuna sausage products.

    Science.gov (United States)

    Kung, Hsien-Feng; Tsai, Yung-Hsiang; Chang, Shih-Chih; Hong, Tang-Yao

    2012-10-01

    Twenty-five tuna sausage products were purchased from retail markets in Taiwan. The rates of occurrence of biogenic amines, histamine-forming bacteria, and adulteration by pork and poultry were determined. The average content of various biogenic amines in all tested samples was less than 2.0 mg/100 g (sausage. The fish species in the tuna sausage samples were identified as Thunnus albacares for 22 samples (88%), Thunnus alalunga for 1 sample (4%), and Thunnus thynnus for 1 sample (4%), whereas the remaining sample was identified as Makaira nigricans (blue marlin).

  10. Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Brandy M.; Santelli, Cara M.; Marcus, Matthew A.; Wirth, Richard; Chan, Clara S.; McCollom, Thomas; Bach, Wolfgang; Edwards, Katrina J.

    2008-05-22

    Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and secondary oxyhydroxide minerals was resolved. The Fe-encrusted biofilms formed preferentially at pyrrhotite-rich (Fe1-xS, 0<_ x<_ 0.2) regions of the incubated chimney sulfide. At the nanometer spatial scale, particles within the biofilm exhibiting lattice fringing and diffraction patterns consistent with 2-line ferrihydrite were identified infrequently. At the micron spatial scale, Fe mu EXAFS spectroscopy and mu XRD measurements indicate that the dominant form of biofilm Fe is a short-range ordered Fe oxyhydroxide characterized by pervasive edge-sharing Fe-O6 octahedral linkages. Double corner-sharing Fe-O6 linkages, which are common to Fe oxyhydroxide mineral structures of 2-line ferrihydrite, 6-line ferrihydrite, and goethite, were not detected in the biogenic iron oxyhydroxide (BIO). The suspended development of the BIO mineral structure is consistent with Fe(III) hydrolysis and polymerization in the presence of high concentrations of Fe-complexing ligands. We hypothesize that

  11. Biogenic amine production by the wine Lactobacillus brevis IOEB 9809 in systems that partially mimic the gastrointestinal tract stress

    Directory of Open Access Journals (Sweden)

    Russo Pasquale

    2012-10-01

    Full Text Available Abstract Background Ingestion of fermented foods containing high levels of biogenic amines (BA can be deleterious to human health. Less obvious is the threat posed by BA producing organisms contained within the food which, in principle, could form BA after ingestion even if the food product itself does not initially contain high BA levels. In this work we have investigated the production of tyramine and putrescine by Lactobacillus brevis IOEB 9809, of wine origin, under simulated gastrointestinal tract (GIT conditions. Results An in vitro model that simulates the normal physiological conditions in the human digestive tract, as well as Caco-2 epithelial human cell lines, was used to challenge L. brevis IOEB 9809, which produced both tyramine and putrescine under all conditions tested. In the presence of BA precursors and under mild gastric stress, a correlation between enhancement of bacterial survival and a synchronous transcriptional activation of the tyramine and putrescine biosynthetic pathways was detected. High levels of both BA were observed after exposure of the bacterium to Caco-2 cells. Conclusions L. brevis IOEB 9809 can produce tyramine and putrescine under simulated human digestive tract conditions. The results indicate that BA production may be a mechanism that increases bacterial survival under gastric stress.

  12. Microbial succession of grass carp (Ctenopharyngodon idellus) filets during storage at 4°C and its contribution to biogenic amines' formation.

    Science.gov (United States)

    Wang, Hang; Luo, Yongkang; Huang, Heping; Xu, Qian

    2014-11-03

    Investigation on the microbial succession of grass carp filets during storage at 4°C was carried out. For identification, 16S rRNA genes of the isolated pure strains were sequenced and analyzed. Acinetobacter was dominant in fresh grass carp. Species from the genera Brevundimonas, Empedobacter, Pseudomonas, Microbacterium, Flavobacterium, Moraxella, Shewanella and Soonwooa were also detected at the initial day. The communities were dominated by Aeromonas and Acinetobacter after 6days. Aeromonas followed by Pseudomonas was the predominant genera at the end of shelf-life of grass carp, while other genera such as Shewanella, Acinetobacter, Flavobacteriaceae and Psychrobacter were present in smaller numbers. We investigated biogenic amines' (BAs) production by six strains isolated from spoiled grass carp filets. Shewanella putrefaciens showed significantly higher abilities to produce putrescine, than those from other genera. Aeromonas veronii revealed a strong ability to produce putrescine and cadaverine. However, Pseudomonas and Acinetobacter showed little ability to produce BAs.

  13. Natural biogenic solid fuels - environmentally relevant characteristics and possible influences. Final report; Naturbelassene biogene Festbrennstoffe - umweltrelevante Eigenschaften und Einflussmoeglichkeiten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, H.; Boehm, T.; Maier, L. [Bayerische Landesanstalt fuer Landtechnik, Friesing-Weihenstephan (Germany). Arbeitsgruppe Festbrennstoffe

    2000-09-01

    , Weizenstroh und Weizenganzpflanzen. Eine Datenbank fuer naturbelassene biogene Festbrennstoffe wurde errichtet. Hierfuer wurde ein relationales Datenbankmodell gewaehlt. Dessen Struktur wurde so angelegt, dass neben den eigentlichen Messgroessen auch eine Vielzahl weiterer Eigenschaften und Informationen zum Brennstoff sowie seine Herkunftsmerkmale und die verwendeten Analyseverfahren festgehalten werden konnten. Die in den eigenen Versuchsserien zustande gekommenen Analyseergebnisse wurden durch weitere Daten aus einer umfangreichen Recherche (Befragung) sowie aus Literaturangaben ergaenzt, so dass insgesamt ca. 1.238 Datensaetze (Stand April 1999) zusammengetragen werden konnten. (orig.)

  14. Fertilizer impact on biogenic nitric oxide emissions from agricultural soils of the Taklimakan desert (Xinjiang, China)

    Science.gov (United States)

    Fechner, A. D.; Behrendt, T.; Bruse, M.; Mamtimin, B.; Andreae, M. O.; Meixner, F. X.

    2012-04-01

    It is known that soil microbial processes play a crucial role in the production and consumption of atmospheric trace gases worldwide. Soils are mostly a major source of biogenic nitric oxide (NO). The main influencing factors controlling soil NO emissions are soil moisture, soil temperature, as well as nutrient availability. Adding fertilizer to agricultural soils changes the pool of nutrients and impacts the net NO emission from these soils. Irrigated and fertilized oases around the great Central Asian Taklamakan desert form the backbone of the agricultural output (80% of the Chinese cotton production) of the Xinjiang Uygur Autonomous Region (NW-China). While nowadays 90% of the agricultural output is produced on just 4.3% of Xinjiang's total area, recent and future enlargement of farmland and intensification of agriculture will definitely impact the regional soil NO emission and consequently the budget of nitrogen oxides and ozone. We present a systematic laboratory study of the influence of urea (CH4N2O) and diammonium hydrogen phosphate ((NH4)2HPO4, DAP) fertilizer on NO emissions from Xinjiang soil samples. Urea is the most widely and excessively applied fertilizer in Xinjiang. Typically, about 600 kg ha-1 yr-1(in terms of mass of nitrogen) were applied to a cotton field in four separate events. In the laboratory, the fertilizer was applied accordingly, ranging from one quarter of the field amount within one of the four events (i.e. 37.5 kg ha-1 yr-1) to quadruple of that (150 kg ha-1 yr-1). Two different measurement series have been performed on six sub- samples (each out of a total of three soil samples taken in Xinjiang): the first series was conducted solely with urea fertilizer, the second one with a mixture of urea and DAP (2:1). All sub-samples were prepared in a standardized way: a fixed mass of soil (~0.06 kg, dried in field) was sieved (2 mm) and stored at 4° C. Then it was wetted up to a soil moisture tension of 1.8 pF. Subsequently, fertilizer was

  15. Self Assembly of Biogenic Surfactants at Mineral Surfaces and Their Effect on Biological Iron Acquisition

    Science.gov (United States)

    Kraemer, S. M.

    2005-12-01

    Microorganisms exude biogenic surfactants to modify the physical and chemical properties of mineral-water interfaces. Surfactants with negatively charged hydrophilic head groups interact strongly with oppositely charged mineral surfaces such as iron or aluminum oxides. Surfactant self assembly at mineral surfaces can result in the formation of admicelles that have a significant effect on the surface charge and hydrophobicity. These effects are exploited by microorganisms to facilitate attachment to mineral surfaces. Similarly, plants exude surfactants into the rhizosphere and change the surface tension and flow of soil water. Other surface active compounds that are typically found in soils and surface waters are humic substances and fatty acids that are produced by degradation of biomass. In general, surface active compounds are ubiquitous in natural systems. In this study we investigated how surfactants influence bio-mineral interactions using the example of siderophore promoted iron acquisition. Siderophore promoted iron acquisition involves the adsorption of a biogenic iron specific ligand (i.e. the siderophore) to iron oxides and the subsequent siderophore promoted iron oxide dissolution. The hypothesis of this project is that the modification of the iron oxide surface charge and hydrophobicity by adsorbed surfactants will have an important effect on siderophore adsorption and dissolution kinetics. We approached this subject by investigating the adsorption of a natural surfactant (rhamnolipids: RhL) and the synthetic surfactant (sodium dodecyl sulfate: SDS) on goethite (α-FeOOH, a common pedogenic iron oxide) and observing the effect of surfactant self assembly on the properties of the mineral water interface. We observed fast adsorption kinetics at pH 3 and slow adsorption at pH 6. The adsorbed surfactants reversed the surface potential of goethite (as evidenced by electrophoretic mobility measurements) at soluble surfactant concentrations below 10 μM (SDS

  16. Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions

    Directory of Open Access Journals (Sweden)

    R. Baghi

    2012-10-01

    Full Text Available Emissions of biogenic volatile organic compounds (BVOC from urban trees during and after blooming were measured during spring and early summer 2009 in Boulder, Colorado. Air samples were collected onto solid adsorbent cartridges from branch enclosures on the tree species crabapple (Malus sp., horse chestnut (Aesculus carnea, "Ft. McNair", honey locust (Gleditsia triacanthos, "Sunburst", and hawthorn (Crataegus laevigata, "Pauls Scarlet". These species constitute ~ 65% of the insect-pollinated fraction of the flowering tree canopy (excluding catkin-producing trees from the street area managed by the City of Boulder. Samples were analyzed for C10–C15 BVOC by thermal desorption and gas chromatography coupled to a flame ionization detector and a mass spectrometer (GC/FID/MS. Identified emissions and emission rates from these four tree species during the flowering phase were found to vary over a wide range. Monoterpene emissions were identified for honey locust, horse chestnut and hawthorn. Sesquiterpene emissions were observed in horse chestnut and hawthorn samples. Crabapple flowers were found to emit significant amounts of benzyl alcohol and benzaldehyde. Floral BVOC emissions increased with temperature, generally exhibiting exponential temperature dependence. Changes in BVOC speciation during and after the flowering period were observed for every tree studied. Emission rates were significantly higher during the blooming compared to the post-blooming state for crabapple and honey locust. The results were scaled to the dry mass of leaves and flowers contained in the enclosure. Only flower dry mass was accounted for crabapple emission rates as leaves appeared at the end of the flowering period. Total normalized (30 °C monoterpene emissions from honey locust were higher during flowering (5.3 μgC g−1 h−1 than after flowering (1.2 μgC g−1 h−1. The total normalized BVOC

  17. Biogenic arsenic volatilisation from an acidic wetland soil

    Science.gov (United States)

    Ilgen, Gunter; Huang, Jen-How; Lu, Shipeng; Tian, Liyan; Alewell, Christine

    2014-05-01

    Biogenic arsenic (As) volatilisation was budgeted at 26000 t yr-1as the largest input of the global As release into the atmosphere, thereby playing an important role in the biogeochemical cycle of As in the surface environment. In order to quantify As volatilisation from wetland soils and to elucidate the geochemical and microbiological factors governing As volatilisation, a series of incubations with an acidic wetland soil collected in NE-Bavaria in Germany were performed at 15oC for 4 months with addition of NaN3, arsenite (As(III)), FeCl3, NaSO4 and NaOAc with N2 and air in the headspace. Speciation of gaseous As in the headspace using GC-ICP-MS/ ESI-MS coupling showed the predominance of either arsine (AsH3) or trimethylarsine ((CH3)3As) in all treatments during the time course of incubation. Monomethylarsine ((CH3)AsH2) and dimethylarsine ((CH3)2AsH) could be only detected in trace amounts. Arsenic speciation in porewater with HPLC-ICP-MS revealed the predominance of As(III) and methylated As was never detectable. Arsenic volatilisation summed to 2.3 ng As (88% as AsH3) in the control incubations, which accounted for ~0.25 % of the total As storage in the wetland soil. Treatments with 10 mM NaN3 resulted in emission of only 0.03 ng As. In contrast, addition of 10 mM NaOAc stimulated microbial activities in wetland soils and subsequently rose As volatilisation to 8.5 ng As. It could be therefore concluded that As volatilisation from the wetland soils was mainly biological. Spiking 67 μM As(III) increased 10 times of As volatilisation and the proportion of methylated arsines increased to 66%, which is supposed to be caused by the largely enhanced As availability in porewater for microbes (480 ppb, ~65 times higher than those in the controls). Adding 10 mM FeCl3 stimulated microbial Fe(III) reducing activities but suppressed other microbial activities by lowering soil pH from 5 to 3.6, decreasing consequently As volatilisation to 0.3 ng As. The much lower redox

  18. Analysis of biogenic amines in wines by salting-out assisted liquid-liquid extraction and high-performance liquid chromatography with fluorimetric detection.

    Science.gov (United States)

    Ramos, Rui Miguel; Valente, Inês Maria; Rodrigues, José António

    2014-06-01

    Biogenic amines are nitrogenous organic compounds of low molecular weight that are either formed or metabolized in cells of living organisms and can be found in several food products, being produced mainly by amino acid decarboxylation. When ingested in high concentrations they can induce several health problems in humans. In alcoholic beverages, and especially in wine, they are formed during the vinification process as a result of the action of microorganisms. In this work it is proposed a new methodology for the determination of biogenic amines in wines, which includes a sample preparation approach based on salting-out assisted liquid-liquid extraction, the use of dansyl chloride for the derivatization and chromatographic separation by high-performance liquid chromatography with fluorimetric detection. The salting-out effect is used to promote phase separation between water and a water-miscible organic solvent, while improving the extraction of organic or inorganic species. Several extraction parameters were optimized, such as the dansyl chloride concentration, pH and the effects caused by the order in which the extraction and derivatization were performed. Extraction of amines, and consequent detection, depends on the presence of dansyl chloride in solution prior to extraction. The results showed the possibility to simultaneously perform the extraction and the derivatization, making sample preparation easier and less time-consuming. The methodology was successfully applied to the determination of biogenic amines in five wines (white, red and rosé). This method has the potential to be a good alternative to existing methods since it is cheaper, easier and simplifies the sample preparation step.

  19. Carbon-14 based determination of the biogenic fraction of industrial CO2 emissions : Application and validation

    NARCIS (Netherlands)

    Palstra, S. W. L.; Meijer, H. A. J.

    2010-01-01

    The C-14 method is a very reliable and sensitive method for industrial plants, emission authorities and emission inventories to verify data estimations of biogenic fractions of CO2 emissions. The applicability of the method is shown for flue gas CO2 samples that have been sampled in I-h intervals at

  20. Ozone Tendency in Biomass Burning Plumes: Influence of Biogenic and Anthropogenic Emissions Downwind of Forest Fires

    Science.gov (United States)

    Finch, D.; Palmer, P. I.

    2015-12-01

    Forest fires emit pollutants that can influence downwind surface concentrations of ozone, with potential implications for exceeding air quality regulations. The influence of emissions from biogenic and anthropogenic sources that are mixed into a biomass burning plume as it travels downwind is not well understood. Using the GEOS-Chem atmospheric chemistry transport model and a novel method to track the centre of biomass burning plumes, we identify the chemical reactions that determine ozone production and loss along the plume trajectory. Using a series of sensitivity runs, we quantify the role of biogenic and anthropogenic emissions on the importance of individual chemical reactions. We illustrate the method using data collected during the BORTAS aircraft campaign over eastern Canada during summer 2011. We focus on two contrasting plume trajectories originating from the same multi-day fire in Ontario. The first plume trajectory on 16th July 2011 travels eastward from the fire and eventually mixes with anthropogenic emissions travelling up the east coast of the United States before outflow over the North Atlantic. The second plume trajectory we follow is three days later and travels eastward with a strong northeast component away from large anthropogenic sources. Both trajectories are influenced by downwind biogenic emissions. We generate a chemical reaction narrative for each plume trajectory, allowing is to quantify how mixing pyrogenic, biogenic and anthropogenic emissions influences downwind ozone photochemistry.

  1. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM A LOWLAND TROPICAL WET FOREST IN COSTA RICA

    Science.gov (United States)

    Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCS) at a lowland tropical wet forest site in Costa Rica. Ten of the species. examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total bas...

  2. Detection and quantification of biogenic amines in fermented food products sold in Botswana.

    Science.gov (United States)

    Magwamba, Clement; Matsheka, Maitshwarelo Ignatius; Mpuchane, Sisai; Gashe, Berhanu Abegaz

    2010-09-01

    The incidence and concentrations associated with four important biogenic amines in leading commercial fermented beverages consumed in Botswana were determined using high-performance liquid chromatography. In 87 sorghum brew and 84 sour milk (madila, amasi) samples tested, putrescine was the most prevalent biogenic amine (63 and 61%, respectively), while histamine was the least prevalent (24 and 8%, respectively). Cadaverine was the most frequently detected biogenic amine in 79 of the commercial sour maize beverage (mageu/mahewu) samples tested (found in 70% of the samples), while tyramine was the least detected (occurring in 3% of the samples). In sorghum brew and sour milk, tyramine was found to be the most concentrated (mean concentration of 2.08 mg/100 ml and 3.2 mg/100 ml, respectively), and histamine was found to be the least concentrated (mean concentration of 0.94 mg/100 ml and 0.31 mg/100 ml, respectively). Overall, the biogenic amine concentrations of all three fermented products were within acceptable limits. However, one sorghum brew sample had a histamine content of 5.8 mg/ 100 ml, which was above the 5.0 mg/100 g allowable limit suggested by the U.S. Food and Drug Administration.

  3. Biogenic amines determination in some traditional cheeses in West Azerbaijan province of Iran

    Directory of Open Access Journals (Sweden)

    Seyed Mehdi Razavi Rohani

    2013-06-01

    Full Text Available Biogenic amines (BA are nitrogenous compounds that possess biological activity. The source of production is the microbial decarboxylation of amino acids. This compounds are found in various types of cheese. The aim of this work was to evaluate the BA content of some traditional cheeses in West Azerbaijan province Iran. For this purpose, 70 samples of Koopeh, 10 samples of Lighvan and 5 samples of Red Salmas cheeses were obtained from local supermarkets of different cities of West Azerbaijan province. After preparation of samples, biogenic amines content was evaluated by modified HPLC method. The presence of histamine, cadaverine, putrescine and tyramine in tested cheeses were observed. Total amount of biogenic amines was highest in Red Salmas cheese with 1426.91 ppm. It followed by Lighvan cheese and Koopeh cheese with 1008.98 and 517.71 ppm, respectively. Putrescine, cadaverine, histamine and tyramine were detected in Koopeh cheese at levels up to 156.09, 282.34, 70.80, 8.48 ppm respectively. These amines were detected also in Lighvan cheese at levels up to 277.53, 342.74, 37.58, 351.12 ppm and in Red Salmas cheese samples at levels up to 438.03, 701.05, 105.21, 182.62 ppm, respectively. Large amounts of biogenic amines can indicate non hygienic conditions and contamination of used milk for cheese production.

  4. Biogenic amines in fish: roles in intoxication, spoilage, and nitrosamine formation--a review.

    Science.gov (United States)

    Al Bulushi, Ismail; Poole, Susan; Deeth, Hilton C; Dykes, Gary A

    2009-04-01

    Biogenic amines are non-volatile amines formed by decarboxylation of amino acids. Although many biogenic amines have been found in fish, only histamine, cadaverine, and putrescine have been found to be significant in fish safety and quality determination. Despite a widely reported association between histamine and scombroid food poisoning, histamine alone appears to be insufficient to cause food toxicity. Putrescine and cadaverine have been suggested to potentiate histamine toxicity. With respect to spoilage on the other hand, only cadaverine has been found to be a useful index of the initial stage of fish decomposition. The relationship between biogenic amines, sensory evaluation, and trimethylamine during spoilage are influenced by bacterial composition and free amino acid content. A mesophilic bacterial count of log 6-7 cfu/g has been found to be associated with 5 mg histamine/100 g fish, the Food and Drug Administration (FDA) maximum allowable histamine level. In vitro studies have shown the involvement of cadaverine and putrescine in the formation of nitrosamines, nitrosopiperidine (NPIP), and nitrosopyrrolidine (NPYR), respectively. In addition, impure salt, high temperature, and low pH enhance nitrosamine formation, whereas pure sodium chloride inhibits their formation. Understanding the relationships between biogenic amines and their involvement in the formation of nitrosamines could explain the mechanism of scombroid poisoning and assure the safety of many fish products.

  5. The impact of biogenic carbon sources on aerosol absorption in Mexico City

    Science.gov (United States)

    Marley, N. A.; Gaffney, J. S.; Tackett, M.; Sturchio, N. C.; Heraty, L.; Martinez, N.; Hardy, K. D.; Marchany-Rivera, A.; Guilderson, T.; MacMillan, A.; Steelman, K.

    2009-03-01

    In order to determine the wavelength dependence of fine (C-4 plants) in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components.

  6. UNITED STATES LAND USE INVENTORY FOR ESTIMATING BIOGENIC OZONE PRECURSOR EMISSIONS

    Science.gov (United States)

    The U.S. Geological Survey's (USGS) Earth Resources Observation System (EROS) Data Center's (EDC) 1-km classified land cover data are combined with other land use data using a Geographic Information System (GIS) to create the Biogenic Emissions Landcover Database (BELD). The land...

  7. Biogenic silica microfossils in sediments of the Permian - Carboniferous Unayzah Formation, Saudi Arabia

    NARCIS (Netherlands)

    Garming, J.F.L.; Franks, S.G.; Cremer, H.; Abbink, O.A.

    2010-01-01

    Biogenic silica particles (BSPs) have been discovered in sediments of the Permian - Carboniferous Unayzah Formation of Saudi Arabia. The BSPs are extracted from sediments that are generally barren of macro- or microfossils. BSPs have been found in the Basal Khuff Clastics (BKC), and the Unayzah A, B

  8. Biogenic silica in space and time in sediments of Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Gupta, S.M.; Mudholkar, A.V.; Parthiban, G.

    silica (30-35%) in the surface sediments from 11 degrees to 13 degrees S, may be due to higher productivity and better preservation of siliceous tests. The lowest biogenic silica at approximately 100 to 140 x 10 sup(3) y BP is suppressed with higher...

  9. Distinguishing black carbon from biogenic humic substances in soil clay fractions

    Science.gov (United States)

    Laird, D.A.; Chappell, M.A.; Martens, D.A.; Wershaw, R. L.; Thompson, M.

    2008-01-01

    Most models of soil humic substances include a substantial component of aromatic C either as the backbone of humic heteropolymers or as a significant component of supramolecular aggregates of degraded biopolymers. We physically separated coarse (0.2-2.0????m e.s.d.), medium (0.02-0.2????m e.s.d.), and fine (> 0.02????m e.s.d.) clay subfractions from three Midwestern soils and characterized the organic material associated with these subfractions using 13C-CPMAS-NMR, DTG, SEM-EDX, incubations, and radiocarbon age. Most of the C in the coarse clay subfraction was present as discrete particles (0.2-5????m as seen in SEM images) of black carbon (BC) and consisted of approximately 60% aromatic C, with the remainder being a mixture of aliphatic, anomeric and carboxylic C. We hypothesize that BC particles were originally charcoal formed during prairie fires. As the BC particles aged in soil their surfaces were oxidized to form carboxylic groups and anomeric and aliphatic C accumulated in the BC particles either by adsorption of dissolved biogenic compounds from the soil solution or by direct deposition of biogenic materials from microbes living within the BC particles. The biogenic soil organic matter was physically separated with the medium and fine clay subfractions and was dominated by aliphatic, anomeric, and carboxylic C. The results indicate that the biogenic humic materials in our soils have little aromatic C, which is inconsistent with the traditional heteropolymer model of humic substances.

  10. Colloidal properties of nanoparticular biogenic selenium govern environmental fate and bioremediation effectiveness

    NARCIS (Netherlands)

    Buchs, B.; Evangelou, M.H.W.; Winkel, L.; Lenz, M.

    2013-01-01

    Microbial selenium (Se) bioremediation is based on conversion of water soluble, toxic Se oxyanions to water insoluble, elemental Se. Formed biogenic elemental Se is of nanometer size, hampering straightforward separation from the aqueous phase. This study represents the first systematic investigatio

  11. The effect of wind and precipitation on vegetation and biogenic crust covers in the Sde-Hallamish sand dunes

    Science.gov (United States)

    Amir, Raz; Kinast, Shai; Tsoar, Haim; Yizhaq, Hezi; Zaady, Eli; Ashkenazy, Yosef

    2014-03-01

    Vegetation and biogenic crust covers play an important role in sand dune stabilization, yet there is a lack of high temporal and spatial resolution data on sand dune cover. A field experiment, aimed at measuring the dynamics of biogenic crust and vegetation in sand dunes, was conducted at the Sde-Hallamish sand dunes in the northwestern Negev Desert, Israel, from July 2008 to August 2010. The climate of the Sde-Hallamish sand dunes is arid (the mean annual precipitation over the past 13 years is 61 mm), and the dunes are linear and partially stable, mainly due to the presence of biogenic crust and partially due to the presence of vegetation. In July 2008, 10×10 m plots on the four dune habitats (crest, interdune, north slope, and south slope) were treated as follows: (i) removal of vegetation and biogenic crust, (ii) removal of biogenic crust only, (iii) removal of vegetation only, (iv) partial removal of biogenic crust and vegetation, and (v) control plot. The surface coverage of sand, biogenic crust, and vegetation was monitored on a monthly basis, using a remote-sensing technique especially developed for the Sde-Hallamish sand dunes. It was found that strong wind events, with durations of several days, accounted for the coverage changes in biogenic crust and vegetation. The response to precipitation was much slower. In addition, no rehabilitation of biogenic crust and vegetation was observed within the experiment time period. The changes in biogenic crust cover were not necessarily related to changes in dune dynamics, since often an increase in biogenic crust cover is a result of wind erosion that exposes old crust that was buried under the sand; wind hardly erodes biogenic crust at all due to its high durability to wind action. The Sde-Hallamish dunes seem to have become more active as a result of a prolonged drought during the past several years. The field experiment reported here indicates that biogenic crust cover exhibits large seasonal variations that are

  12. New procedure of selected biogenic amines determination in wine samples by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

    2014-06-27

    Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

  13. Biocompatibility assessment of rice husk-derived biogenic silica nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Alshatwi, Ali A., E-mail: alshatwi@ksu.edu.sa; Athinarayanan, Jegan; Periasamy, Vaiyapuri Subbarayan

    2015-02-01

    Synthetic forms of silica have low biocompatibility, whereas biogenic forms have myriad beneficial effects in current toxicological applications. Among the various sources of biogenic silica, rice husk is considered a valuable agricultural biomass material and a cost-effective resource that can provide biogenic silica for biomedical applications. In the present study, highly pure biogenic silica nanoparticles (bSNPs) were successfully harvested from rice husks using acid digestion under pressurized conditions at 120 °C followed by a calcination process. The obtained bSNPs were subjected to phase identification analysis using X-ray diffraction, which revealed the amorphous nature of the bSNPs. The morphologies of the bSNPs were observed using transmission electron microscopy (TEM), which revealed spherical particles 10 to 30 nm in diameter. Furthermore, the biocompatibility of the bSNPs with human lung fibroblast cells (hLFCs) was investigated using a viability assay and assessing cellular morphological changes, intracellular ROS generation, mitochondrial transmembrane potential and oxidative stress-related gene expression. Our results revealed that the bSNPs did not have any significant incompatibility in these in vitro cell-based approaches. These preliminary findings suggest that bSNPs are biocompatible, could be the best alternative to synthetic forms of silica and are applicable to food additive and biomedical applications. - Highlights: • Simple, rapid and convenient process • Amorphous and spherical with 10–30 nm size SiO{sub 2} nanoparticles were fabricated. • Biogenic silica nanoparticles showed biocompatibility. • bSNPs are an alternative to synthetic forms of silica.

  14. Modeling of microbial gas generation: application to the eastern Mediterranean “Biogenic Play”

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.; Dubille, M.; Montadert, L.

    2016-07-01

    Biogenic gas is becoming increasingly important as an exploration target in the petroleum industry because it occurs in geologically predictable circumstances and in large quantities at shallow depths as free gas or gas hydrates. As accumulations of biogenic gas result in a subtle synchronization between early generation and early trapping, we integrated a macroscopic model of microbial gas generation within a 3D basin and petroleum system forward simulator. The macroscopic model is based on a microscopic model, which consists in a 1D sedimentary column that accounts for sedimentation, compaction, Darcy flow and Diffusion flow. The organic carbon is the only non-soluble element considered in this version of the model. The dissolved elements are O2, SO4 2-, H2, CH3COOH, and CH4. Methane is dissolved in water or present as a free phase if its concentration exceeds its solubility at given pressure and temperature. In this microscopic model, the transformation of substrate into biomass is described through a set of logistic equations coupled with the transport equations (advection and diffusion). Based on the microscopic considerations we developed the macroscopic model of low maturity/biogenic gas generation in which hydrocarbons are generated through first order kinetic reactions at low maturity. This macroscopic model is adapted to petroleum system modeling at basin scale with TemisFlow®, which aims to understand and predict hydrocarbon generation, migration, and accumulation. It is composed of: i) A source rock criteria which allow defining the biogenic gas source rocks potential and ii) A kinetic model of methane generation. The previous model has been successfully applied on different basins such as the Carupano Basin from the offshore Venezuela, the Magdalena Delta (offshore Colombia) and the offshore Vietnam where direct observations of low-maturity gas were available. Furthermore, it has been applied in the offshore Lebanon in order to check the viability of

  15. Improved MEGAN predictions of biogenic isoprene in the contiguous United States

    Science.gov (United States)

    Wang, Peng; Schade, Gunnar; Estes, Mark; Ying, Qi

    2017-01-01

    Isoprene emitted from biogenic sources significantly contributes to ozone and secondary organic aerosol formation in the troposphere. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) has been widely used to estimate isoprene emissions from local to global scales. However, previous studies have shown that MEGAN significantly over-predicts isoprene emissions in the contiguous United States (US). In this study, ambient isoprene concentrations in the US were simulated by the Community Multiscale Air Quality (CMAQ) model (v5.0.1) using biogenic emissions estimated by MEGAN v2.10 with several different gridded isoprene emission factor (EF) fields. Best isoprene predictions were obtained with the EF field based on the Biogenic Emissions Landcover Database v4 (BELD4) from US EPA for its Biogenic Emission Inventory System (BEIS) model v3.61 (MEGAN-BEIS361). A seven-month simulation (April to October 2011) of isoprene emissions with MEGAN-BEIS361 and ambient concentrations using CMAQ shows that observed spatial and temporal variations (both diurnal and seasonal) of isoprene concentrations can be well predicted at most non-urban monitors using isoprene emission estimation from the MEGAN-BEIS361 without significant biases. The predicted monthly average vertical column density of formaldehyde (HCHO), a reactive volatile organic compound with significant contributions from isoprene oxidation, generally agree with the spatial distribution of HCHO column density derived using satellite data collected by the Ozone Monitoring Instrument (OMI), although summer month vertical column densities in the southeast US were overestimated, which suggests that isoprene emission might still be overestimated in that region. The agreement between observation and prediction may be further improved if more accurate PAR values, such as those derived from satellite-based observations, were used in modeling the biogenic emissions.

  16. Arsenite Removal from Simulated Groundwater by Biogenic Schwertmannite: A Column Trial

    Institute of Scientific and Technical Information of China (English)

    XIE Yue; ZHOU Li-Xiang

    2013-01-01

    To assess the feasibility of biogenic schwertmannite to act as a sorbent for removing arsenite from groundwater,a series of biogenic schwertmannite-packed column adsorption experiments were conducted on simulated As(Ⅲ)-containing groundwater.Empty bed contact time (EBCT),As(Ⅲ) concentration in effluent,and the removal efficiency of As(Ⅲ) through the column were investigated at pH 8.0 and temperature 25 ± 0.5 ℃.The results showed that the breakthrough curves were mainly dependent on EBCT values when the influent As(Ⅲ) concentration was 500 μg L-1 and the optimum EBCT was 4.0 min.When the effluent As(Ⅲ) concentration reached 10 and 50 μg L-1,the breakthrough volumes for the schwertmannite adsorption column were 4200 and 5600 bed volume (BV),with As(Ⅲ) adsorption capacity of 2.1 and 2.8 mg g-1,respectively.Biogenic schwertmannite could be regenerated by 1.0 mol L-1 NaOH solution,and more than 80% of As(Ⅲ) adsorbed on the surface of schwertmannite could be released after 3 successive regenerations.The breakthrough volume for the regenerated schwertmannite-packed column still maintained 4 000-4 200 BV when the As(Ⅲ) concentration in effluent was below 10 μg L-1.Compared with other sorbents for As(Ⅲ) removal,the biogenic schwertmannitepacked column had a higher breakthrough volume and a much higher adsorption capacity,implying that biogenic schwertmannite was a highly efficient and potential sorbent to purify As(Ⅲ)-contaminated groundwater.

  17. 酿酒工艺对葡萄酒中生物胺的影响%Effects of Different Vintage Technologies on the Formation of Biogenic Amines in Dry Red Wines

    Institute of Scientific and Technical Information of China (English)

    于英; 李记明; 姜文广; 赵荣华

    2011-01-01

    The effects of different vintage technologies(pectases,yeasts,malolactic bacterias and fermentation temperature) on the formation of biogenic amines(histamine,2-phenylethylamine,tyramine,tryptamine,putrescine, cadaverine,spermidine and spermine) in Cabernet Gernischt wines during vinification were studied using high pressure liquid chromatography.The results showed that biogenic amines were generated mainly from alcoholic fermentation and malo-lactic fermentation during winemaking,and the former had low concentrations of biogenic amines.The concentrations of putrescine and spermine produced during alcoholic fermentation could be controlled by pectases,inoculum concentration of yeast,fermentation temperature.The biogenic amines in dry red wines were produced mostly by malolactic bacterias,and histamine and tryptamine were largely from malo-lactic fermentation.%探讨了不同酿酒工艺对葡萄酒中生物胺(组胺、苯乙胺、酪胺、色胺、腐胺、尸胺、精胺和亚精胺)含量的影响。结果显示,葡萄酒酿造过程中生物胺主要在酒精发酵和苹果酸-乳酸发酵过程产生。酒精发酵过程生成量较少,主要产生腐胺和精胺,果胶酶的使用、酵母接种量、发酵温度等因素可以调节酒精发酵过程生物胺的生成量;乳酸菌是葡萄酒生物胺最主要来源,在苹果酸-乳酸发酵过程中会产生大量的组胺和色胺。

  18. Biogenic nanoparticle-mediated augmentation of seed germination, growth, and antioxidant level of Eruca sativa mill. varieties.

    Science.gov (United States)

    Ushahra, Jyoti; Bhati-Kushwaha, Himakshi; Malik, C P

    2014-09-01

    A study was undertaken to examine the influence of biogenic nanoparticles synthesized from Tridax procumbens on different parameters of seed germination, seedling growth, and various biochemical parameters in four Eruca sativa varieties having low percentage of germination. Seeds were treated with different concentrations (30 and 40 ppm) of biogenic nanoparticles, of which 30 ppm was found to be the most effective and was therefore used for subsequent studies. Initially, the effect of biogenic nanoparticles on germination percentage, speed of germination, coefficient of germination, mean germination time, shoot and root length, fresh and dry matter, and vigor index was studied. From the experiments performed and the results obtained, it was evident that the treatment with biogenic nanoparticles decreased the electrolyte leakage and level of malondialdehyde as compared to control. The treatment with biogenic nanoparticles enhanced the levels of proline and ascorbic acid and stimulated the antioxidant enzyme activities resulting in the reduced level of reactive oxygen species. These activities were found to be variety-dependent. The possible involvement of biogenic nanoparticles in the production of new pores in seed coat during their penetration, resulting in the influx of the nutrients inside the seed, is suggested. This accelerated seed germination is followed by rapid seedling growth. The present findings indicated that biogenic nanoparticles promote seed germination in E. sativa by overcoming the detrimental effects of reactive oxygen species (ROS) and improving the antioxidative defense system which finally result in increased seedling growth.

  19. Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality

    Science.gov (United States)

    Gentner, D. R.; Ormeño, E.; Fares, S.; Ford, T. B.; Weber, R.; Park, J.-H.; Brioude, J.; Angevine, W. M.; Karlik, J. F.; Goldstein, A. H.

    2014-06-01

    Agriculture comprises a substantial, and increasing, fraction of land use in many regions of the world. Emissions from agricultural vegetation and other biogenic and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of particulate matter (PM2.5). Using data from three measurement campaigns, we examine the magnitude and composition of reactive gas-phase organic carbon emissions from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions from motor vehicles in California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone PM2.5. Emission rates for a suite of terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008. Ambient measurements of terpenoids and other biogenic compounds in the volatile and intermediate-volatility organic compound ranges were made in the urban area of Bakersfield and over an orange orchard in a rural area of the San Joaquin Valley during two 2010 seasons: summer and spring flowering. We combined measurements from the orchard site with ozone modeling methods to assess the net effect of the orange trees on regional ozone. When accounting for both emissions of reactive precursors and the deposition of ozone to the orchard, the orange trees are a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall, when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such biogenic emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by several factors to over an order of magnitude. In regions like the San Joaquin Valley, the mass of biogenic

  20. Origin of the Putrescine-Producing Ability of the Coagulase-Negative Bacterium Staphylococcus epidermidis 2015B

    NARCIS (Netherlands)

    Coton, Emmanuel; Mulder, Niels; Coton, Monika; Pochet, Sylvie; Trip, Hein; Lolkema, Juke S.

    2010-01-01

    A multiplex PCR method, aimed at the detection of genes associated with biogenic amine production, identified the odc gene encoding ornithine decarboxylase in 1 of 15 strains of Staphylococcus epidermidis. The ability of the positive strain, S. epidermidis 2015B, to produce putrescine in vitro was d

  1. Biogenic amines as freshness index of meat wrapped in a new active packaging system formulated with essential oils of Rosmarinus officinalis.

    Science.gov (United States)

    Sirocchi, Veronica; Caprioli, Giovanni; Cecchini, Cinzia; Coman, Maria Magdalena; Cresci, Alberto; Maggi, Filippo; Papa, Fabrizio; Ricciutelli, Massimo; Vittori, Sauro; Sagratini, Gianni

    2013-12-01

    Biogenic amines (BAs) are considered as an important indicator of freshness and quality of food. In this work, a new active packaging (AP) system for meat that, incorporating essential oil of Rosmarinus officinalis at 4% (w/w), inhibits the increase of BAs and the bacteria involved into their production was developed. BAs were analyzed by a SPE-HPLC-DAD method during the storage time of meat (0-7 d, 4 °C). Results showed that, in each monitored day, Biogenic Amine Index (BAI) expressed in mg kg(-1) is lower in meat wrapped in AP with respect to that packed in polycoupled packaging (PP) (from 19% to 62%). A strong correlation was found between the inhibition of increase of putrescine, cadaverine, histamine and their bacteria producers such as Enterobacteriaceae, Pseudomonas spp. and Brocothrix thermospacta. By exploiting antimicrobial and antioxidant action of essential oil of R. officinalis, the new APs contribute to increase the shelf life of fresh meat and to preserve its important nutrients.

  2. High-temperature removal of sulphur for biogenic gas products; Hochtemperatur-Entschwefelung fuer biogene Produktgase. Design und Optimierung - Schlussbericht/Jahresbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schildhauer, T.; Biollaz, S.

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning the development of basics ideas on the design and optimisation of high-temperature methods for the removal of sulphur from biogenic gas products. Tests made as part of the 'Methane from Wood' project at pilot installations in Switzerland and Austria are discussed. Low temperature and high-temperature methods are examined and discussed. A number of sulphur compounds were tested. Also, experiments made using nickel, HDS and CPO catalysers are discussed.

  3. Biogenic precipitation of manganese oxides and enrichment of heavy metals at acidic soil pH

    Science.gov (United States)

    Mayanna, Sathish; Peacock, Caroline L.; Schäffner, Franziska; Grawunder, Anja; Merten, Dirk; Kothe, Erika; Büchel, Georg

    2014-05-01

    The precipitation of biogenic Mn oxides at acidic pH is rarely reported and poorly understood, compared to biogenic Mn oxide precipitation at near neutral conditions. Here we identified and investigated the precipitation of biogenic Mn oxides in acidic soil, and studied their role in the retention of heavy metals, at the former uranium mining site of Ronneburg, Germany. The site is characterized by acidic pH, low carbon content and high heavy metal loads including rare earth elements. Specifically, the Mn oxides were present in layers identified by detailed soil profiling and within these layers pH varied from 4.7 to 5.1, Eh varied from 640 to 660 mV and there were enriched total metal contents for Ba, Ni, Co, Cd and Zn in addition to high Mn levels. Using electron microprobe analysis, synchrotron X-ray diffraction and X-ray absorption spectroscopy, we identified poorly crystalline birnessite (δ-MnO2) as the dominant Mn oxide in the Mn layers, present as coatings covering and cementing quartz grains. With geochemical modelling we found that the environmental conditions at the site were not favourable for chemical oxidation of Mn(II), and thus we performed 16S rDNA sequencing to isolate the bacterial strains present in the Mn layers. Bacterial phyla present in the Mn layers belonged to Firmicutes, Actinobacteria and Proteobacteria, and from these phyla we isolated six strains of Mn(II) oxidizing bacteria and confirmed their ability to oxidise Mn(II) in the laboratory. The biogenic Mn oxide layers act as a sink for metals and the bioavailability of these metals was much lower in the Mn layers than in adjacent layers, reflecting their preferential sorption to the biogenic Mn oxide. In this presentation we will report our findings, concluding that the formation of natural biogenic poorly crystalline birnessite can occur at acidic pH, resulting in the formation of a biogeochemical barrier which, in turn, can control the mobility and bioavailability of heavy metals in

  4. Biogenic isoprene and implications for oxidant levels in Beijing during the 2008 Olympic Games

    Science.gov (United States)

    Chang, C.-C.; Shao, M.; Chou, C. C. K.; Liu, S.-C.; Wang, J.-L.; Lee, K.-Z.; Lai, C.-H.; Zhu, T.; Lin, P.-H.

    2013-10-01

    As the host of the 2008 Summer Olympic Games, Beijing implemented a series of stringent, short-term air quality control measures to reduce the emissions of anthropogenic air pollutants. Large reductions in the daily average concentrations of primary pollutants, e.g., non-methane hydrocarbons (NMHCs) and nitrogen oxides (NOx) of approximately 50% were observed at the air quality observatory of Peking University. Nevertheless, high levels of ozone were present during the control period. Although anthropogenic precursors were greatly reduced, the meteorological conditions in summer, including high temperature and light flux, are conducive to the production of large amounts of biogenic isoprene, which is extremely reactive. The diurnal pattern of isoprene showed daily maximum mixing ratios of 0.83 ppbv at noon and a minimum at night, reflecting its primarily biogenic properties. Using the ratio of isoprene to vehicle exhaust tracers, approximately 92% of the daytime isoprene was estimated from biogenic sources, and only 8% was attributed to vehicular emissions. In terms of OH reactivity and the ozone formation potential (OFP), biogenic isoprene with its midday surge can contribute approximately 20% of the total OFPs and 40-50% of the total OH reactivities of the 65 measured NMHCs during the midday hours. The discrepancy between decreased precursor levels and the observed high ozone was most likely caused by a combination of many factors. The changes in the partition among the components of oxidation products (O3, NO2 and NOz) and the contribution of air pollutants from regional sources outside Beijing should be two primary reasons. Furthermore, the influences of biogenic isoprene as well as the non-linearity of O3-VOC-NOx chemistry are other major concerns that can reduce the effectiveness of the control measures for decreasing ozone formation. Although anthropogenic precursors were greatly reduced during the Olympic Games, sufficient biogenic isoprene and moderate NOx

  5. Biogenic isoprene and implications for oxidant levels in Beijing during the 2008 Olympic Games

    Science.gov (United States)

    Chang, Chih-Chung; Shao, Min; Chou, Charles C. K.; Liu, Shaw-Chen; Zhu, Tong; Lee, Kun-Zhang; Lai, Cheng-Hsun; Lin, Po-Hsiung; Wang*, Jia-Lin

    2014-05-01

    As the host of the 2008 Summer Olympic Games, Beijing implemented a series of stringent, short-term air quality control measures to reduce the emissions of anthropogenic air pollutants. Large reductions in the daily average concentrations of primary pollutants, e.g., non-methane hydrocarbons (NMHCs) and nitrogen oxides (NOx) of approximately 50% were observed at the air quality observatory of Peking University. Nevertheless, high levels of ozone were present during the control period. Although anthropogenic precursors were greatly reduced, the meteorological conditions in summer, including high temperature and light flux, are conducive to the production of large amounts of biogenic isoprene, which is extremely reactive. The diurnal pattern of isoprene showed daily maximum mixing ratios of 0.83 ppbv at noon and a minimum at night, reflecting its primarily biogenic properties. Using the ratio of isoprene to vehicle exhaust tracers, approximately 92% of the daytime isoprene was estimated from biogenic sources, and only 8% was attributed to vehicular emissions. In terms of OH reactivity and the ozone formation potential (OFP), biogenic isoprene with its midday surge can contribute approximately 20% of the total OFPs and 40-50% of the total OH reactivities of the 65 measured NMHCs during the midday hours. The discrepancy between decreased precursor levels and the observed high ozone was most likely caused by a combination of many factors. The changes in the partition among the components of oxidation products (O3, NO2 and NOz) and the contribution of air pollutants from regional sources outside Beijing should be two primary reasons. Furthermore, the influences of biogenic isoprene as well as the non-linearity of O3-VOC-NOx chemistry are other major concerns that can reduce the effectiveness of the control measures for decreasing ozone formation. Although anthropogenic precursors were greatly reduced during the Olympic Games, the presence of sufficient biogenic isoprene

  6. Cavity-Enhanced Gas Analyzer for In-Situ Sampling of Biogenic Gases and Their Isotopes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project concerns the novel application of cavity-enhanced absorption spectroscopy to quantify biogenic gases (CH4,...

  7. Salting-out assisted liquid-liquid extraction for the determination of biogenic amines in fruit juices and alcoholic beverages after derivatization with 1-naphthylisothiocyanate and high performance liquid chromatography.

    Science.gov (United States)

    Jain, Archana; Gupta, Manju; Verma, Krishna K

    2015-11-27

    A new method for determining biogenic amines in fruit juices and alcoholic beverages is described involving reaction of biogenic amines with 1-naphthylisothiocyanate followed by extraction of 1-naphthylthiourea derivatives with water-miscible organic solvent acetonitrile when solvents phase separation occurred using ammonium sulphate, a process called salting-out assisted liquid-liquid extraction. The extract was analyzed by high-performance liquid chromatography with UV detection at 254nm. The new reagent avoided many of the inconveniences as observed with existing derivatizing agents, such as dansyl chloride and benzoyl chloride, in regard to their inselectivity, instability, adverse effect of excess reagent, and necessity to remove excess reagent. The procedure has been optimized with respect to reaction time and temperature, water-miscible extraction solvent, and salt for solvents phase separation. Use of reagent as dispersed phase in aqueous medium produced derivatives in high yield. A linear calibration was obtained between the amount of biogenic amines in range 1-1000μgL(-1) and peak areas of corresponding thioureas formed; the correlation coefficient was 0.9965, and the limit of detection and limit of quantification found were 1.1μgL(-1) and 3.2μgL(-1), respectively. The pre-concentration method gave an average enrichment factor of 94. The application of the method has been demonstrated in the determination of biogenic amines in commercial samples of fruit juices and alcoholic beverages. In spiking experiments to real samples, the average recovery found by the present method was 94.5% that agreed well with 95.8% obtained by established comparison methods.

  8. Biogenic amine accumulation in silver carp sausage inoculated with Lactobacillus plantarum plus Saccharomyces cerevisiae.

    Science.gov (United States)

    Nie, Xiaohua; Zhang, Qilin; Lin, Shengli

    2014-06-15

    The effect of an amine-negative mixed starter culture (Lactobacillus plantarum ZY40 plus Saccharomyces cerevisiae JM19) on biogenic amine accumulation in fermented silver carp sausage was studied. Microbial counts, pH, titratable acid and free amino acids were also determined. Putrescine, cadaverine and tyramine were the main amines formed during sausage fermentation. The contents of putrescine and cadaverine were greatly reduced by the addition of L. plantarum ZY40 plus S. cerevisiae JM19, whereas tyramine accumulation was enhanced as compared to the control batch. Histamine and spermidine were not affected by the mixed starter culture, and their levels varied slightly throughout the fermentation. Besides, no positive correction between pH, free amino acid content and biogenic amine accumulation were found.

  9. Biogenic carbon in combustible waste: Waste composition, variability and measurement uncertainty

    DEFF Research Database (Denmark)

    Larsen, Anna Warberg; Fuglsang, Karsten; Pedersen, Niels H.;

    2013-01-01

    described in the literature. This study addressed the variability of biogenic and fossil carbon in combustible waste received at a municipal solid waste incinerator. Two approaches were compared: (1) radiocarbon dating (14C analysis) of carbon dioxide sampled from the flue gas, and (2) mass and energy...... balance calculations using the balance method. The ability of the two approaches to accurately describe short-term day-to-day variations in carbon emissions, and to which extent these short-term variations could be explained by controlled changes in waste input composition, was evaluated. Finally...... method and the balance method represented promising methods able to provide good quality data for the ratio between biogenic and fossil carbon in waste. The relative uncertainty in the individual experiments was 7–10% (95% confidence interval) for the 14C method and slightly lower for the balance method....

  10. Biogenic Amines as Quality Marker in Organic and Fair-Trade Cocoa-Based Products

    Directory of Open Access Journals (Sweden)

    Donatella Restuccia

    2016-08-01

    Full Text Available In this study, the quantitative determination of eight biogenic amines (cadaverine, serotonin, histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine by an liquid chromatography method with evaporative light scattering detection was performed. The analysis of several samples of conventional, organic and fair trade cocoa-derivatives showed that organic and fair trade samples always contain much lower amine concentrations in comparison with their conventional counterparts, supporting the idea that biogenic amines can be regarded as cocoa quality markers. Irrespective of the kind of sample, results also showed that the most abundant amines were histamine, tyramine, spermidine, putrescine and spermine while β-phenylethylamine, cadaverine and serotonine have been found more rarely, all the amines never reaching dangerous amounts for consumer health. With the aim to confirm the experimental results, clustering analysis was performed on samples and instrumental results using principal component analysis.

  11. BIOGENIC INFLUENCES ON THE FORMATION AND LONG-TERM DYNAMICS OF COHESIVE SEDIMENTS

    Institute of Scientific and Technical Information of China (English)

    Joern V. PROCHNOW; C. SCHWEIM; Juergen KOENGETER

    2001-01-01

    Biogenic stabilization processes that result in the formation of biofilms and interparticle-networks can significantly alter the transport characteristics of finegrained sediment layers. The increase in the threshold of sediment motion can amount to up to several hundred percent. While planctic organisms are involved in the formation of depositing flocs and the early stages of consolidation, the secondary consolidation is controlled by microbial breakdown processes, leading to changes in the mechanical properties of cohesive sediments. While the primary stage of consolidation is completed in days, the secondary processes can last for decades. A preliminary series of erosion tests in an annular flume revealed demonstrated the biogenic impact in the early stages of sediment formation. Surrogate materials were used to simulate the governing properties of natural soft sediments.

  12. The effects of atmospheric [CO2] on carbon isotope fractionation and magnesium incorporation into biogenic marine calcite

    Science.gov (United States)

    Vieira, Veronica

    1997-01-01

    The influences of atmospheric carbon dioxide on the fractionation of carbon isotopes and the magnesium incorporation into biogenic marine calcite were investigated using samples of the calcareous alga Amphiroa and benthic foraminifer Sorites grown in the Biosphere 2 Ocean system under variable atmospheric CO2 concentrations (approximately 500 to 1200 ppm). Carbon isotope fractionation was studied in both the organic matter and the skeletal carbonate. Magnesium analysis was to be performed on the carbonate removed during decalcification. These data have not been collected due to technical problems. Carbon isotope data from Amphiroa yields a linear relation between [CO2] and Delta(sup 13)C(sub Corg)values suggesting that the fractionation of carbon isotopes during photosynthesis is positively correlated with atmospheric [CO2]. [CO2] and Delta(sup 13)C(sub Corg) values for Sorites produce a relation that is best described by a hyperbolic function where Delta(sup 13)C(sub Corg) values increase between 300 and 700 ppm and decrease from 700 to 1200 ppm. Further investigation of this relation and Sorites physiology is needed.

  13. Assessment of the genetic polymorphism and biogenic amine production of indigenous Oenococcus oeni strains isolated from Greek red wines.

    Science.gov (United States)

    Pramateftaki, P V; Metafa, M; Karapetrou, G; Marmaras, G

    2012-02-01

    In the warm climate country of Greece malolactic fermentation (MLF) has received limited attention. Molecular techniques and High Performance Liquid Chromatography (HPLC) were used to study the genetic polymorphism of autochthonous lactic acid bacteria developing towards the end of spontaneous MLF of Greek red wines and for the assessment of their potential to produce harmful biogenic amines. This research revealed that native Oenococcus oeni isolates are very much adapted to specific winery conditions since the majority of spontaneous MLF were driven mostly or exclusively by a single strain of O. oeni. Native O. oeni strains showed only limited dispersion since cluster analysis uncovered only few common genotypes among indigenous isolates from different wineries. The genotype of a frequently used malolactic starter was more than often detected among autochthonous isolates without nevertheless compromising the biodiversity of natural microflora residing in wineries but rather becoming a part of it. For the majority of the wine samples studied, MLF implementation and storage in bottles resulted in negligible changes on the levels of the BA histamine, tyramine, phenylethylamine, cadaverine as well as of ethylamine, methylamine, isobutylamine. We provide evidence that autochthonous O. oeni isolates can only contribute to putrescine accumulation in Greek wines but still the specific trait behaves as strain-specific with a limited dispersion.

  14. Truncated Hexa-Octahedral Magnetite Crystals in Martian Meteorite ALH84001: Evidence of Biogenic Activity on Early Mars

    Science.gov (United States)

    Thomas-Keprta, K.; Clemett, S. J.; Schwartz, C.; McIntosh, J. R.; Bazylinski, D. A.; Kirschvink, J.; McKay, D. S.; Gibson, E. K.; Vali, H.; Romanek, C. S.

    2004-01-01

    The landmark paper by McKay et al. [1] cited four lines of evidence associated with the Martian meteorite ALH84001 to support the hypothesis that life existed on Mars approximately 4 Ga ago. Now, more than five years later, attention has focused on the ALH84001 magnetite grains embedded within carbonate globules in the ALH84001 meteorite. We have suggested that up to approx.25% of the ALH84001 magnetite crystals are products of biological activity [e.g., 2]. The remaining magnetites lack sufficient characteristics to constrain their origin. The papers of Thomas Keprta et al. were criticized arguing that the three dimensional structure of ALH84001 magnetite crystals can only be unambiguously determined using electron tomographic techniques. Clemett et al. [3] confirmed that magnetites produced by magnetotactic bacteria strain MV-I display a truncated hexa-octahedral geometry using electron tomography and validated the use of the multi-tilt classical transmission microscopy technique used by [2]. Recently the geometry of the purported martian biogenic magnetites was shown be identical to that for MV-1 magnetites using electron tomography [6].

  15. 800 year ice-core record of nitrogen deposition in Svalbard linked to ocean productivity and biogenic emissions

    Directory of Open Access Journals (Sweden)

    I. A. Wendl

    2014-09-01

    Full Text Available We present the records of the two nitrogen species nitrate (NO3− and ammonium (NH4+ analysed in a new ice core from Lomonosovfonna, Svalbard, in the Eurasian Arctic covering the period 1222–2009. We investigate the emission sources and the influence of melt on the records. During the 20th century both records are influenced by anthropogenic pollution from Eurasia. In pre-industrial times NO3− is highly correlated with methane-sulfonate (MSA on decadal time-scales, which we explain by a fertilising effect. Enhanced atmospheric NO3− concentrations and the corresponding nitrogen input to the ocean trigger the growth of dimethyl-sulfide-(DMS-producing phytoplankton. Increased DMS production results in elevated fluxes to the atmosphere where it is oxidised to MSA. Eurasia was presumably the main source area also for pre-industrial NO3−, but a more exact source apportionment could not be performed based on our data. This is different for NH4+, where biogenic ammonia (NH3 emissions from Siberian boreal forests were identified as the dominant source of pre-industrial NH4+. Changes in melt at the Lomonosovfonna glacier are excluded as major driving force for the decadal variations of the investigated compounds.

  16. Biogenic methanol and its impacts on tropospheric oxidants

    Science.gov (United States)

    Tie, Xuexi; Guenther, Alex; Holland, Elisabeth

    2003-09-01

    We use a global chemical transport model (MOZART-2) to estimate the effects of surface emissions of methanol on tropospheric oxidants. The importance of methanol in tropospheric chemistry is two fold. First, methanol has a relatively large surface emission with an estimated global emission of 70 to 350 Tg methanol/year. The estimated methanol flux is comparable to other major hydrocarbon surface emissions such as isoprene and total monoterpenes, but the chemical lifetime of methanol is several days (in the boundary layer) to a few weeks (in the upper troposphere), which is much longer than the chemical lifetime of isoprene or monoterpenes (For example, the chemical lifetime of isoprene is about 2 hours). With a surface emission of 104 to 312 Tg methanol/year (encompasses estimated uncertainty in methanol emissions), the calculation shows that on average, the inclusion of methanol emission produces approximately 1-2% increase in O3, 1-3% decrease in OH, 3-5% increase in HO2, and 3-9% increase in CH2O globally. The maximum perturbation to the oxidants occurs in the tropical upper troposphere. However, the uncertainty associated with current methanol emission estimates produces significantly different model predictions of tropospheric oxidant distributions.

  17. Incremental Reactivity Effects on Secondary Organic Aerosol Formation in Urban Atmospheres with and without Biogenic Influence

    Science.gov (United States)

    Kacarab, Mary; Li, Lijie; Carter, William P. L.; Cocker, David R., III

    2016-04-01

    Two different surrogate mixtures of anthropogenic and biogenic volatile organic compounds (VOCs) were developed to study secondary organic aerosol (SOA) formation at atmospheric reactivities similar to urban regions with varying biogenic influence levels. Environmental chamber simulations were designed to enable the study of the incremental aerosol formation from select anthropogenic (m-Xylene, 1,2,4-Trimethylbenzene, and 1-Methylnaphthalene) and biogenic (α-pinene) precursors under the chemical reactivity set by the two different surrogate mixtures. The surrogate reactive organic gas (ROG) mixtures were based on that used to develop the maximum incremental reactivity (MIR) factors for evaluation of O3 forming potential. Multiple incremental aerosol formation experiments were performed in the University of California Riverside (UCR) College of Engineering Center for Environmental Research and Technology (CE-CERT) dual 90m3 environmental chambers. Incremental aerosol yields were determined for each of the VOCs studied and compared to yields found from single precursor studies. Aerosol physical properties of density, volatility, and hygroscopicity were monitored throughout experiments. Bulk elemental chemical composition from high-resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) data will also be presented. Incremental yields and SOA chemical and physical characteristics will be compared with data from previous single VOC studies conducted for these aerosol precursors following traditional VOC/NOx chamber experiments. Evaluation of the incremental effects of VOCs on SOA formation and properties are paramount in evaluating how to best extrapolate environmental chamber observations to the ambient atmosphere and provides useful insights into current SOA formation models. Further, the comparison of incremental SOA from VOCs in varying surrogate urban atmospheres (with and without strong biogenic influence) allows for a unique perspective on the impacts

  18. Structure, Function, and Evolution of Biogenic Amine-binding Proteins in Soft Ticks

    Energy Technology Data Exchange (ETDEWEB)

    Mans, Ben J.; Ribeiro, Jose M.C.; Andersen, John F. (NIH)

    2008-08-19

    Two highly abundant lipocalins, monomine and monotonin, have been isolated from the salivary gland of the soft tick Argas monolakensis and shown to bind histamine and 5-hydroxytryptamine (5-HT), respectively. The crystal structures of monomine and a paralog of monotonin were determined in the presence of ligands to compare the determinants of ligand binding. Both the structures and binding measurements indicate that the proteins have a single binding site rather than the two sites previously described for the female-specific histamine-binding protein (FS-HBP), the histamine-binding lipocalin of the tick Rhipicephalus appendiculatus. The binding sites of monomine and monotonin are similar to the lower, low affinity site of FS-HBP. The interaction of the protein with the aliphatic amine group of the ligand is very similar for the all of the proteins, whereas specificity is determined by interactions with the aromatic portion of the ligand. Interestingly, protein interaction with the imidazole ring of histamine differs significantly between the low affinity binding site of FS-HBP and monomine, suggesting that histamine binding has evolved independently in the two lineages. From the conserved features of these proteins, a tick lipocalin biogenic amine-binding motif could be derived that was used to predict biogenic amine-binding function in other tick lipocalins. Heterologous expression of genes from salivary gland libraries led to the discovery of biogenic amine-binding proteins in soft (Ornithodoros) and hard (Ixodes) tick genera. The data generated were used to reconstruct the most probable evolutionary pathway for the evolution of biogenic amine-binding in tick lipocalins.

  19. Aging of biogenic secondary organic aerosol via gas-phase OH radical reactions

    DEFF Research Database (Denmark)

    Donahue, Neil M.; Henry, Kaytlin M.; Mentel, Thomas F.;

    2012-01-01

    The Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) tested the hypothesis that hydroxyl radical (OH) aging significantly increases the concentration of first-generation biogenic secondary organic aerosol (SOA). OH is the dominant atmospheric oxidant, and MUCHACHAS employed environmental...... with an existing gap between global SOA sources and those predicted in models, and can be described by a mechanism suitable for implementation in those models....

  20. A Review: Microbiological, Physicochemical and Health Impact of High Level of Biogenic Amines in Fish Sauce

    Directory of Open Access Journals (Sweden)

    Muhammad Z. Zaman

    2009-01-01

    Full Text Available Problem statement: Biogenic amines are basic nitrogenous compounds present in a wide variety of foods and beverages. Their formations were mainly due to the amino acids decarboxylase activity of certain microorganisms. Excessive intake of biogenic amines could induce many undesirable physiological effects determined by their psychoactive and vasoactive action. Fish sauce which is considered as a good source of dietary protein, amino acids, vitamins and minerals was a popular condiment in Southeast Asian countries. However, it has also been reported that fish sauce contain high amount of amines. Hence, attention should be given to ensure the safety of this product. Approach: A review study was conducted to deliver an overview on the presence of biogenic amines in fish sauce and to discuss the important factors affecting their accumulation. Impact of amines on human health and efforts to reduce their accumulation in fish sauce were also discussed to give a comprehensive view. Results: Histamine, putrescine and cadaverine is the most abundant amines in fish sauce with maximum reported value of 1220, 1257 and 1429 ppm, respectively. Tyramine present in a lesser amount with maximum reported value of 1178 ppm. Other amines such as tryptamine, phenylethylamine, spermine and spermidine were considered as minor amines. However, different profiles of amines were reported in different type of products. This was depended on microbial flora, availability of precursors and physicochemical factors such as temperature, pH, salt, oxygen and sugar concentration. In synergistically supporting physicochemical factors, several microorganisms such as Enterobacteriaceae, Micrococci and Lactobacilli were responsible for biogenic amines formation in fish sauce. Conclusion: Since the formation of amines in fish sauce was a result of many factors, it was almost virtually impossible to control each factor during fermentation. Addition of amines degrading bacteria into fish

  1. PM10-biogenic fraction drives the seasonal variation of proinflammatory response in A549 cells.

    Science.gov (United States)

    Camatini, Marina; Corvaja, Viviana; Pezzolato, Eleonora; Mantecca, Paride; Gualtieri, Maurizio

    2012-02-01

    PM10 was collected in a Milan urban site, representative of the city air quality, during winter and summer 2006. Mean daily PM10 concentration was 48 μg m(-3) during summer and 148 μg m(-3) during winter. Particles collected on Teflon filters were chemically characterized and the endotoxin content determined by the LAL test. PM10-induced cell toxicity, assessed with MTT and LDH methods, and proinflammatory potential, monitored by IL-6 and IL-8 cytokines release, were investigated on the human alveolar epithelial cell line A549 exposed to increasing doses of PM. Besides untreated cells, exposure to inert carbon particles (2-12 μm) was also used as additional control. Both cell toxicity and proinflammatory potency resulted to be higher for summer PM10 with respect of winter PM10, with IL-6 showing the highest dose-dependent release. The relevance of biogenic components adsorbed onto PM10 in eliciting the proinflammatory mediators release was investigated by inhibition experiments. Polymixin B (Poly) was used to inhibit particle-bind LPS while Toll-like receptor-2 antibody (a-TLR2) to specifically block the activation of this receptor. While cell viability was not modulated in cells coexposed to PM10 and Poly or a-TLR2 or both, inflammatory response did it, with IL-6 release being the most inhibited. In conclusion, Milan PM10-induced seasonal-dependent biological effects, with summer particles showing higher cytotoxic and proinflammatory potential. Cytotoxicity seemed to be unaffected by the PM biogenic components, while inflammation was significantly reduced after the inhibition of some biogenic activated pathways. Besides, the PM-associated biogenic activity does not entirely justify the PM-induced inflammatory effects. © 2010 Wiley Periodicals, Inc. Environ Toxicol 2012.

  2. Methyl chavicol: characterization of its biogenic emission rate, abundance, and oxidation products in the atmosphere

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2009-03-01

    Full Text Available We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol was detected simultaneously by three in-situ instruments – a gas chromatograph with mass spectrometer detector (GC-MS, a proton transfer reaction mass spectrometer (PTR-MS, and a thermal desorption aerosol GC-MS (TAG – and found to be abundant within and above Blodgett Forest. Methyl chavicol atmospheric mixing ratios are strongly correlated with 2-methyl-3-buten-2-ol (MBO, a light- and temperature-dependent biogenic emission from the ponderosa pine trees at Blodgett Forest. Scaling from this correlation, methyl chavicol emissions account for 4–68% of the carbon mass emitted as MBO in the daytime, depending on the season. From this relationship, we estimate a daytime basal emission rate of 0.72–10.2 μgCg−1 h−1, depending on needle age and seasonality. We also present the first observations of its oxidation products (4-methoxybenzaldehyde and 4-methyoxy benzene acetaldehyde in the ambient atmosphere. Methyl chavicol is a major essential oil component of many plant species. This work suggests that methyl chavicol plays a significant role in the atmospheric chemistry of Blodgett Forest, and potentially other sites, and should be included explicitly in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  3. Methyl chavicol: characterization of its biogenic emission rate, abundance, and oxidation products in the atmosphere

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2008-11-01

    Full Text Available We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol was detected simultaneously by three in-situ instruments – a gas chromatograph with mass spectrometer detector (GC-MS, a proton transfer reaction mass spectrometer (PTR-MS, and a thermal desorption aerosol GC-MS (TAG – and found to be abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Methyl chavicol atmospheric mixing ratios are strongly correlated with 2-methyl-3-buten-2-ol (MBO, a light- and temperature-dependent biogenic emission from the ponderosa pine trees at Blodgett Forest. Scaling from this correlation, methyl chavicol emissions account for 4–68% of the carbon mass emitted as MBO in the daytime, depending on the season. From this relationship, we estimate a daytime basal emission rate of 0.72–10.2 μgCg−1h−1, depending on needle age and seasonality. We also present the first observations of its oxidation products (4-methoxybenzaldehyde and 4-methyoxy benzene acetaldehyde in the ambient atmosphere. Methyl chavicol is a major essential oil component of many plant species. This work suggests that methyl chavicol plays a significant role in the atmospheric chemistry of Blodgett Forest, and potentially other sites, and should be included explicitly in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  4. Quantitative laboratory measurements of biogeochemical processes controlling biogenic calcite carbon sequestration.

    Energy Technology Data Exchange (ETDEWEB)

    Zendejas, Frank; Lane, Todd W.; Lane, Pamela D.

    2011-01-01

    The purpose of this LDRD was to generate data that could be used to populate and thereby reduce the uncertainty in global carbon cycle models. These efforts were focused on developing a system for determining the dissolution rate of biogenic calcite under oceanic pressure and temperature conditions and on carrying out a digital transcriptomic analysis of gene expression in response to changes in pCO2, and the consequent acidification of the growth medium.

  5. Life Cycle Assessment of age-related environmental impact of biogenic hydraulic fluids; Life Cycle Assessment der alterungsbedingten Umweltvertraeglichkeit biogener Hydraulik-Schmierstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Bressling, Jana

    2012-07-01

    Biogenic hydraulic fluids, based on synthetic esters (category: HEES), have an excellent environmental profile in the unused state, so that they are typically classified into water hazard class 1 or as ''not hazardous to water''. During storage at room temperature and tribological application, occurring chemical and toxicological changes take no account in the classification of lubricants until now. However, the ageing and oxidation stability gets increasing importance, since it determines the service life of lubricants in tribological systems in addition to the storage time. Since it always comes to direct and uncontrolled entries into the environment in case of accidents or hydraulic leaks, it is essential to assess whether there is an environmental hazard by waste oils. With an increased use of biogenic hydraulic fluids in environmentally sensitive areas, thus the need for an appropriate monitoring and assessment approach as part of a Life Cycle Assessment (LCA). The aquatic and miniaturised test procedures applied in this work with the Water Soluble Fraction (WSF) concept, allows a simple and quick screening of age-related ecotoxic potential of lubricants by oxidative processes and tribological application. For detection of genotoxic potential the umu-test is a suitable indicator test to detect geno- and cytotoxic effects by oxidative reactions. The determination of biodegradability is essential for the assessment of the environmental impact of hydraulic fluids. The optimised biodegradability test system ''O2/CO2-Headspace Test'' has proved itself as a suitable procedure for the investigation of biogenic lubricants within the scope of a LCA and shows therefore a comparable method of the required test procedures for the assignment of ecolabels. In addition, the combination of biological test procedures and chemical analysis allows a comprehensive investigation of effects and causes of age-related changes of hydraulic

  6. Biogenic Amine Degradation by Bacillus Species Isolated from Traditional Fermented Soybean Food and Detection of Decarboxylase-Related Genes.

    Science.gov (United States)

    Eom, Jeong Seon; Seo, Bo Young; Choi, Hye Sun

    2015-09-01

    Biogenic amines in some food products present considerable toxicological risks as potential human carcinogens when consumed in excess concentrations. In this study, we investigated the degradation of the biogenic amines histamine and tyramine and the presence of genes encoding histidine and tyrosine decarboxylases and amine oxidase in Bacillus species isolated from fermented soybean food. No expression of histidine and tyrosine decarboxylase genes (hdc and tydc) were detected in the Bacillus species isolated (B. subtilis HJ0-6, B. subtilis D'J53-4, and B. idriensis RD13-10), although substantial levels of amine oxidase gene (yobN) expression were observed. We also found that the three selected strains, as non-biogenic amineproducing bacteria, were significantly able to degrade the biogenic amines histamine and tyramine. These results indicated that the selected Bacillus species could be used as a starter culture for the control of biogenic amine accumulation and degradation in food. Our study findings also provided the basis for the development of potential biological control agents against these biogenic amines for use in the food preservation and food safety sectors.

  7. Biogenic non-methane hydrocarbons (NMHC). Nature`s contribution to regional and global atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Klockow, D.; Hoffman, T. [Inst. of Spectrochemistry and Applied Spectroscopy, Dortmund (Germany)

    1995-12-31

    Terrestrial vegetation provides an important source of volatile hydrocarbons, especially isoprene, monoterpenes and in addition possibly sesquiterpenes as well as oxygenated compounds. Although there exist considerable uncertainties in the estimation of the magnitude of these biogenic NMHC emissions, it is generally accepted that the majority of global NMHC release is from natural and not from anthropogenic sources. Taking into consideration the high reactivity of the mostly unsaturated biogenic emissions, their impact on tropospheric processes can be assumed to be of great importance. Together with anthropogenic NO{sub x} emissions, the highly reactive natural alkenes can act as precursors in photochemical oxidant formation and contribute to regional-scale air pollution. Their oxidation in the atmosphere and the subsequent gas-to-particle conversion of the products lead to the formation of organic aerosols. Because of the formation of phytotoxic compounds, the interaction of the biogenic hydrocarbons with ozone inside or outside the leaves and needles of plants has been suggested to play a role in forest decline. (author)

  8. Neogene biogenic sediments of onshore Peru: part I, sedimentology and stratigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Marty, R.C.; Dunbar, R.B.; Baker, P.

    1985-01-01

    The Sechura (approx.6/sup 0/S) and Pisco (approx.14/sup 0/S) Basins of onshore Peru contain Miocene diatom and phosphate rich sediments which sharply contrast with underlying clastics. In the Sechura Basin the Miocene clastic Mancora, Heath and Montera Formations are overlain by the Zapallal Formation which grades upwards from a weakly biogenic base into fairly pure diatomites (biogenic silica >20%) and ore grade phosphorite (P/sub 2/O/sub 5/>20%). Biogeneic content decreases in the eastern basin as clastic content increases. The base of the Zapallal Formation has been dated at between 12.2 and 14.0 mybp using radiolaria correlated to magnetic stratigraphy by Theyer, et al (1978), and the phosphatic section yields dates of between 8.0 and 11.2 my. In the Pisco Basin the Eocene clastic Paracas Formation is overlain unconformably by the Miocene Pisco Formation which contains a basal sequence of cross-bedded clastics, tuffs, and partially recrystallized diatomites; a phosphorite bearing middle sequence; and a diatom rich top. Current direction from the cross beds of the basal Pisco Formation indicate a generally southerly transport direction but with considerable directional variability. This may be related to the Peru under-current which shows highly variable strength and direction near 15/sup 0/S.

  9. The Functions of China Marginal Sea Sediments in the Cycle of Biogenic Elements

    Institute of Scientific and Technical Information of China (English)

    Sun Yunming; Song Jinming

    2002-01-01

    The contents of biogenic elements in China marginal sea sediments are related to their grain sizes, river transport, et al. In general, the finer the grain size is, the higher the contents of organic matter and OC, N, P are, the lower the contents of S and Si are. The biogeochemical environments of sediments are related to Eh, pH, temperature content of OC,Fe3+/Fe2+ radio, water dynamics condition, grain size of sediment, S system in sediment interstitial waters, et al., and they influence the early diageneses and cycle of biogenic elements in sediments. In most regions of China marginal sea, the flux directions of S2-, HS-,3- NH4+H4SiO4, PO4 , across the sediment-water interface are from sediment to the overlying seawater, the flux directions of SO42-, HCO3-, NO3-, NO2- across the sediment-water interface are from the overlying seawater to sediment. The irrigation of living things is important in the cycle of the biogenic elements across sediment-water interfaces.

  10. Biogen's portfolio and research efforts in multiple sclerosis: an interview with Dr Ralph Kern.

    Science.gov (United States)

    Kern, Ralph

    2017-02-01

    Ralph Kern speaks to Laura Dormer, Commissioning Editor: Dr Ralph Kern is Senior Vice President and Head of Worldwide Medical at Biogen in Cambridge, MA, USA. In this role, he oversees Biogen's global therapeutic, regional and country medical teams, global medical operations, as well as medical research and scientific communications functions. Prior to joining Biogen, he was head of the Neuroscience Medical Unit at Novartis Pharmaceuticals Corporation and held various medical and commercial leadership roles at Genzyme Corporation. Prior to joining industry, he was a consultant neurologist at Mount Sinai Hospital and the University Health Network in Toronto, Ontario and was head of the neurology postgraduate academic program at the University of Toronto. Ralph completed neurology postgraduate training at McGill University and completed a masters of health administration from the Institute for Health Policy, Management and Evaluation at the University of Toronto. He is a member of the College of Physicians and Surgeons of Ontario and the Royal College of Physicians and Surgeons of Canada.

  11. Identification of the biogenic compounds responsible for size-dependent nanoparticle growth

    Science.gov (United States)

    Winkler, Paul M.; Ortega, John; Karl, Thomas; Cappellin, Luca; Friedli, Hans R.; Barsanti, Kelley; McMurry, Peter H.; Smith, James N.

    2012-10-01

    The probability that freshly nucleated nanoparticles can survive to become cloud condensation nuclei is highly sensitive to particle growth rates. Much of the growth of newly formed ambient nanoparticles can be attributed to oxidized organic vapors originating from biogenic precursor gases. In this study we investigated the chemical composition of size-selected biogenic nanoparticles in the size range from 10 to 40 nm. Particles were formed in a flow tube reactor by ozonolysis of α-pinene and analyzed with a Thermal Desorption Chemical Ionization Mass Spectrometer. While we found similar composition in 10 and 20 nm particles, the relative amounts of individual species varied significantly when compared to 40 nm particles. Smaller particles (10 and 20 nm) were characterized by enhancements in carboxylic acids and larger particles (40 nm) showed higher concentrations of carbonyl-containing compounds and low molecular weight organic acids. This composition change from smaller to larger size particles reflects a vapor pressure increase of the condensing vapors by 1-2 orders of magnitude indicating that the Kelvin effect plays a decisive role in the growth of biogenic nanoparticles.

  12. Estimates for biogenic non-methane hydrocarbons and nitric oxide emissions in the Valley of Mexico

    Science.gov (United States)

    Velasco, Erik

    Biogenic non-methane hydrocarbons (NMHC), 2-methyl-3-buten-2-ol (methylbutenol or MBO) and nitrogen oxide (NO) emissions were estimated for the Valley of Mexico developing a spatially and temporally resolved emission inventory for air quality models. The modeling domain includes all the Metropolitan Mexico City Area, the surrounding forests and agriculture fields. The estimates were based on several sources of land use and land cover data and a biogenic emission model; the biomass density and tree characteristics were obtained from reforestation program data. The biogenic emissions depend also on climatic conditions, mainly temperature and solar radiation. The temperature was obtained from a statistical revision of the last 10 yr data reported by the Mexico City Automatic Atmospheric Monitoring Network, while the solar radiation data were obtained from measurements performed in a typical oak forest in the Valley and from sources of total solar radiation data for Mexico City. The results indicated that 7% of total hydrocarbon emissions in Mexico Valley are due to vegetation and NO emissions from soil contribute with 1% to the total NO x emissions.

  13. Evidence for the biogenic origin of manganese-enriched layers in Lake Superior sediments.

    Science.gov (United States)

    Palermo, Christine; Dittrich, Maria

    2016-04-01

    Manganese (Mn) and iron (Fe)-enriched sediment layers were discovered in Lake Superior within, above and below the oxic-anoxic interface. While the role of bacteria in redox reactions with Mn is known to be significant, little information exists about indigenous microbial communities in many freshwater environments. This study examined the bacterial communities of Mn-enriched layers in Lake Superior to identify the potential Mn(II) oxidizers responsible for the formation of Mn oxides. Anaerobic Mn(II) oxidation occurring in the Mn-enriched layers at the oxic-anoxic interface was investigated using Mn(II)-enriched cultures. High-resolution microscopic and spectroscopic investigations provided evidence of the biogenic formation of Mn oxides on cell surfaces. Spectroscopic mapping confirmed high levels of Mn in structures resembling biogenic Mn oxides. These structures were observed in enrichment cultures and in Mn-enriched layer sediment samples, indicating the significance of biogenic Mn oxidation occurring in situ. 16S ribosomal DNA pyrosequencing was used to identify the bacteria potentially responsible for Mnoxide formation in the enrichment cultures and Mn-enriched layers, revealing that the Mn-enriched layer contains classes with known Mn(II)-oxidizing members. Pyrosequencing of bacterial cultures suggested that these bacteria may be Bacillus strains, and that anaerobic microbial-mediated Mn(II) oxidation contributes to the formation of the layers.

  14. BIOGENIC AMINE CONTENT AND CHEMICAL AND PHYSICAL FEATURES OF ITALIAN FORMAGGIO DI FOSSA

    Directory of Open Access Journals (Sweden)

    S Rea

    2010-06-01

    Full Text Available Formaggio di Fossa is an Italian traditional cheese of the Montefeltro area (Emilia Romagna and Marche regions characterized by a particular step of ripening that is carried out into pits (infossamento borne in the sandstone. Since the XIV century, the inhabitants were used to set food, especially cereals and cheese, into pits to preserve them during winter and to protect them from invaders. The aim of the present work is to study physical and chemical features of this product with particular reference to the presence of the most important biogenic amines ( -Phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermine and spermidine, compared with a control cheese fully ripened in factory. Formaggio di Fossa showed higher values of Aw, pH, humidity, proteins, pH 4,6-soluble nitrogen (NCN and water soluble nitrogen (NPN and much lower amounts of fat. Much higher amounts of total biogenic amines were detected in Formaggio di Fossa than in control cheese, where their concentration was very low. Cadaverine, putrescine and tyramine were the most concentrated biogenic amines. Nevertheless, thyramine was present at levels suggested as compatible with GMPs. Histamine was detected at low amounts, far from potentially toxic levels.

  15. Biogenic iron mineralization at Iron Mountain, CA with implications for detection with the Mars Curiosity rover

    Science.gov (United States)

    Williams, Amy J.; Sumner, Dawn Y.; Alpers, Charles N.; Campbell, Kate M.; Nordstrom, D. Kirk

    2014-01-01

    (Introduction) Microbe-mineral interactions and biosignature preservation in oxidized sulfidic ore bodies (gossans) are prime candidates for astrobiological study. Such oxidized iron systems have been proposed as analogs for some Martian environments. Recent studies identified microbial fossils preserved as mineral-coated filaments. This study documents microbially-mediated mineral biosignatures in hydrous ferric oxide (HFO) and ferric oxyhydroxysulfates (FOHS) in three environments at Iron Mountain, CA. We investigated microbial community preservation via HFO and FOHS precipitation and the formation of filamentous mineral biosignatures. These environments included 1) actively precipitating (1000's yrs), naturally weathered HFO from in situ gossan, and 3) remobilized iron deposits, which contained lithified clastics and zones of HFO precipitate. We used published biogenicity criteria as guidelines to characterize the biogenicity of mineral filaments. These criteria included A) an actively precipitating environment where microbes are known to be coated in minerals, B) presence of extant microbial communities with carbon signatures, C) structures observable as a part of the host rock, and D) biological morphology, including cellular lumina, multiple member population, numerous taxa, variable and 3-D preservation, biological size ranges, uniform diameter, and evidence of flexibility. This study explores the relevance and detection of these biosignatures to possible Martian biosignatures. Similar filamentous biosignatures are resolvable by the Mars Hand Lens Imager (MAHLI) onboard the Mars Science Laboratory (MSL) rover, Curiosity, and may be identifiable as biogenic if present on Mars.

  16. Role of biogenic amines in pathogenesis of dust induced respiratory diseases

    Energy Technology Data Exchange (ETDEWEB)

    Talakin, Yu.N.; Deinega, V.G.; Gridneva, N.V.; Levitskaya, V.A.

    1987-06-01

    Studies metabolism of biogenic amines, catecholamine, histamine and serotonin and their part in pathophysiologic mechanisms of bronchial obstruction in chronic dust bronchitits of coal miners. Three groups of miners, 50 healthy controls, 200 with pneumoconiosis and 95 with chronic dust bronchitis were tested to determine content in blood of histamine, serotonin, activity of histaminase, monoaminoxidase (MAO), daily elimination in urine of 5-oxyindoleacetic acid, adrenalin, noradrelin, dopamine and dopa. Results processed statistically are shown in a table (changes of indices of metabolism of biogenic amines in blood of coal miners). Healthy miners show increased catabolism of serotonin. During stage 1 pneumoconiosis, evacuation of noradrenalin is increased and emission of dopamine with urine decreases, level of histamine in blood rises, activity of MOA and excretion of 5-oxyindoleacetic acid increase. In chronic dust bronchitis depression of mediator link of sympathetic adrenalin system is augmented, level of histamine of blood rises with lowered histaminopexia. Activity of MAO and evacuation of 5-oxyindoleacetic increase. To evaluate the condition of metabolism of biogenic amines, it is advisable in clinical practice to use informative biochemical criteria in combination with physiologic methods of investigation to conduct provocative and pharmacologic tests in order to approach differentially establishment of a basic curative treatment complex and improve effectiveness of therapy. 16 refs.

  17. Effects of biogenic amines on the testicular development in mud crabs Scylla serrata

    Institute of Scientific and Technical Information of China (English)

    YE Haihui; HUANG Huiyang; LI Shaojing; WANG Guizhong; LI Qifu

    2006-01-01

    The regulation of three biogenic amines over the reproductive neuroendocrine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the mature sections in testes, and the ratio of Type B cells in androgenic gland were taken as the quantitative indexes. The in vivo injections indicated that: 5-HT can significantly promote the testicular development and the secretion of the androgenic gland in S. serrata; DA can inhibit the testicular development, but no influence on the secretion of the androgenic gland was found; no significant difference was observed between the OA-injected group and the concurrent control group. In vitro incubations showed that: 5-HT can stimulate the secretion of the brain and the thoracic ganglia, thus accelerating that of the androgenic gland; however, neither OA nor DA showed any significant influence on the secretion of the brain and the thoracic ganglionic mass. As to the optic ganglia, the three biogenic amines hardly have any effect on its secretion. It is the first time to report the regulation of biogenic amines over the reproductive neuroendocrine of male crustaceans through vitro experiments.Results corroborate that 5-HT activates the brain and the thoracic ganglia to secret GSH first, then promote the testicular development through the activity of the androgenic gland.

  18. Organic aerosol formation from biogenic compounds over the Ponderosa pine forest in Colorado

    Science.gov (United States)

    Roux, Alma Hodzic; Lee-Taylor, Julia; Cui, Yuyan; Madronich, Sasha

    2013-05-01

    The secondary organic aerosol (SOA) formation and regional growth from biogenic precursors is of particular interest given their abundance in the atmosphere, and has been investigated during the Rocky Mountain Biogenic Aerosol field Study in 2011 in the pine forest canopy (dominated by terpene emissions) using both WRF/Chem 4km simulations and the GECKO-A explicit chemistry box-model runs. We have quantified the relative contribution of different biogenic precursors to SOA levels that were measured by the aerosol mass spectrometer at the site, and investigated the relative contribution of OH, O3 and NO3 chemistry to the formed SOA mass during day-and nighttime. Although, the local production and mass concentrations of submicron organic aerosols at the site seem relatively modest ˜1-2 ug/m3, we show that the optically active regional mass is increased as the SOA formation continues for several days in the background forest air. We investigate whether the simplified SOA parameterizations used in 3D models can capture this growth. In addition, preliminary comparisons of the number concentrations and the composition of ultrafine particles (8 - 30nm) from WRF/Chem simulations and TD-CIMS measurements are also discussed, and the contribution of organic aerosols to CCN formation is quantified.

  19. Seasonal variation in utilization of biogenic microhabitats by littorinid snails on tropical rocky shores.

    Science.gov (United States)

    Cartwright, Stephen R; Williams, Gray A

    2012-01-01

    Mobile species may actively seek refuge from stressful conditions in biogenic habitats on rocky shores. In Hong Kong, the upper intertidal zone is extremely stressful, especially in summer when organisms are emersed for long periods in hot desiccating conditions. As a result, many species migrate downshore between winter and summer to reduce these stressful conditions. The littorinids Echinolittorina malaccana and E. vidua, for example, are found on open rock surfaces high on the shore in winter but the majority migrate downshore in summer to the same tidal height as a common barnacle, Tetraclita japonica. In the laboratory, where environmental conditions could be controlled to approximate those occurring on the shore, we tested whether the downshore migration allowed littorinids to select barnacles as biogenic habitats to reduce stress and if this behaviour varied between seasons. In summer, littorinids demonstrated a strong active preference for the barnacles, which was not observed in the cool winter conditions, when animals were found on open rock surfaces even when barnacles were present. Littorinids, therefore, only actively select biogenic habitats during the summer in Hong Kong when they migrate downshore, suggesting that such habitats may play an important, temporal, role in mitigating environmental stress on tropical shores.

  20. Can the biogenicity of Europa's surfical sulfur be tested simultaneously with penetrators and ion traps?

    Science.gov (United States)

    Chela-Flores, J.; Bhattacherjee, A. B.; Dudeja, S.; Kumar, N.; Seckbach, J.

    2009-04-01

    We suggest a biogenic interpretation of the sulfur patches on the Europan icy surface. This hypothesis is testable by LAPLACE, or a later mission, in which the instrumentation on board are penetrators, or ion traps, with component selection including miniaturized mass spectrometry. The argument in favor of such instrumentation and component selection is as follows: Extreme environments with microbes can act as models for extraterrestrial life (Seckbach et al., 2008). Suggestions have ranged from Venusian environments (Sagan, 1967, Seckbach and Libby, 1970) to Mars (Grilli Caiola and Billi, 2007). Active photosynthetic microbial communities are found on Antarctica, both in and on ice, in fresh water, in saline lakes and streams and within rocks. In the dry valley lakes of Antarctica close to the McMurdo Base, microbial mats are known to selectively remove a huge quantity of sulfur (Parker et al., 1982). Lake Vostok in Antarctica possesses a perennially thick (3 to 4 km) ice-cover that precludes photosynthesis, thus making this subglacial environment a good model system for determining how a potential Europan biota might emerge, evolve and distribute itself. Jupiter's moon Europa may harbor a subsurface water ocean, which lies beneath an ice layer that might be too thick to allow photosynthesis, just as in Lake Vostok. However, disequilibrium chemistry driven by charged particles from Jupiter's magnetosphere could produce sufficient organic and oxidant molecules for an Europan biosphere (Chyba, 2000). We restrict our attention to microbial mats that could still be thriving in spite of the extreme conditions of radiation on Europa. We are especially concerned with sulfur patches discovered by the Galileo mission. In the near future there are technologies available to settle the question of habitability on Europa, such as penetrators that are currently being developed for preliminary trials nearer to the Earth—the Moon-Lite mission (Smith et al., 2008). If analogies

  1. Deforestation and Biogenic Trace Emissions from Brazilian Cerrado

    Science.gov (United States)

    Sinha, Ravi; Geol, P.

    1996-01-01

    The overall goal of NASA's SCAR (Smoke, Cloud and Radiation) Program is to obtain physical and chemical properties of the smoke produced by biomass burning and the effects of the smoke on the earth's radiation balance and climate. It is a joint project with the Brazilian government and their organizations, including INPE (Instituto Nacional Pesquisas Espaciais) who actively participate in all activities. Appropriate estimates of the biomass buming in the tropics is therefore essential to determine its effect on the atmosphere and on climate. The SCAR series of experiments is designed with that purpose. The present study of evaluating the burnt-out areas is to augment the data collected to date to help evaluate the effect of biomass burning.

  2. Microbes produce nanobacteria-like structures, avoiding cell entombment

    Science.gov (United States)

    Bontognali, Tomaso R. R.; Vasconcelos, Crisógono; Warthmann, Rolf J.; Dupraz, Christophe; Bernasconi, Stefano M.; McKenzie, Judith A.

    2008-08-01

    Microsedimentary structures referred to as nanobacteria-likeparticles were described from modern carbonate environments,where they form in close spatial association with sulfate-reducingbacteria (SRB). However, the exact mechanism of their formation,as well as their paleontological significance, remains controversial.Here we report on an investigation of microbe-mineral interactionsin experimentally produced carbonate globules. The experimentswere carried out under anoxic conditions at 30 °C with Desulfovibriobrasiliensis, a SRB known to mediate dolomite formation. Weobserved that extracellular polymeric substances (EPS) secretedby the microbial community play a key role in the mineralizationprocess. Nanobacteria-like particles represent the early stageof carbonate nucleation within the EPS, which progressivelyevolve to larger globules displaying a grainy texture. We excludedthe possibilities that these structures are fossils of nanobacteria,dissolution surfaces, or artifacts created during sample preparation.D. brasiliensis cells are predominantly located outside of theEPS aggregates where mineral growth takes place. As a result,they remain mobile and are rarely entombed within the mineral.This self-preservation behavior may not be limited to D. brasiliensis.Other microbes may produce, or may have produced during thegeological past, biogenic minerals through a similar process.Mineralization within EPS explains why microbial relics arenot necessarily present in biogenic carbonates.

  3. The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates

    Science.gov (United States)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2017-04-01

    Rare earth elements (REEs) are commonly used proxies to reconstruct water chemistry and oxygen saturation during the formation of authigenic and biogenic phosphates in marine environments. In the modern ocean REEs exhibit a distinct pattern with enrichment of heavy REEs and strong depletion in cerium (Ce). The wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry has been very different in the Earth's past. However, both early and late diagenesis are known to affect REE signatures in phosphates altering primary marine signals. Herein we present a dataset of REE signatures in 38 grain specific LA-ICP-MS measurements of isolated phosphate and carbonate grains in three discrete rock samples. The phosphates mainly consist of authigenic phosphates and phosphatized microfossils that formed in a microbially mediated micro-milieu. In addition, isolated biogenic and reworked phosphatic grains are also present. The phosphates are emplaced in bioclastic grain- to packstones deposited on a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene Monterey event. The results reveal markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Grain shape and REE patterns together indicate that authigenic, biogenic and reworked phosphates have distinct REE patterns irrespective of the sample. Our study shows that while REE patterns in phosphates do reflect water chemistry during authigenesis, they are often already heavily altered during reworking, a process, which can occur in geologically negligible timespans. REE patterns are therefore more likely to reflect complex enrichment processes after their formation. Similarities in the REE patterns of reworked and biogenic phosphate further suggest that the

  4. Measurements of Primary Biogenic Aerosol Particles with an Ultraviolet Aerodynamic Particle Sizer (UVAPS) During AMAZE-08

    Science.gov (United States)

    Wollny, A. G.; Garland, R.; Pöschl, U.

    2008-12-01

    Biogenic aerosols are ubiquitous in the Earth's atmosphere and they influence atmospheric chemistry and physics, the biosphere, climate, and public health. They play an important role in the spread of biological organisms and reproductive materials, and they can cause or enhance human, animal, and plant diseases. Moreover, they influence the Earth's energy budget by scattering and absorbing radiation, and they can initiate the formation of clouds and precipitation as cloud condensation and ice nuclei. The composition, abundance, and origin of biogenic aerosol particles and components are, however, still not well understood and poorly quantified. Prominent examples of primary biogenic aerosol particles, which are directly emitted from the biosphere to the atmosphere, are pollen, bacteria, fungal spores, viruses, and fragments of animals and plants. During the AMazonian Aerosol CharacteriZation Experiment (AMAZE-08) a large number of aerosol and gas-phase measurements were taken on a remote site close to Manaus, Brazil, during a period of five weeks in February and March 2008. The presented study is focused on data from an ultraviolet aerodynamic particle sizer (UVAPS, TSI inc.) that has been deployed for the first time in Amazonia. In this instrument, particle counting and aerodynamic sizing over the range of 0.5-20 μm are complemented by the measurement of UV fluorescence at 355 nm (excitation) and 420-575 nm (emission), respectively. Fluorescence at these wavelengths is characteristic for reduced pyridine nucleotides (e.g., NAD(P)H) and for riboflavin, which are specific for living cells. Thus particles exhibiting fluorescence signals can be regarded as 'viable aerosols' or 'fluorescent bioparticles' (FBAP), and their concentration can be considered as lower limit for the actual abundance of primary biogenic aerosol particles. First data analyses show a pronounced peak of FBAP at diameters around 2-3 μm. In this size range the biogenic particle fraction was

  5. Brown carbon formation from ketoaldehydes of biogenic monoterpenes

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tran B.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2013-04-10

    Sources and chemical composition of the brown carbon are poorly understood, and even less is known about the mechanisms of its atmospheric transformations. This work presents molecular level investigation of the reactive compound ketolimononaldehyde (KLA, C9H14O3), a second generation ozonolysis product of limonene (C10H16), as a potent brown carbon precursor in secondary organic aerosol (SOA) through its reactions with reduced nitrogen compounds such as ammonium ion (NH4+), ammonia, and amino acids. The reactions of synthesized and purified KLA with NH4+ and glycine resulted in the formation of chromophores nearly identical in spectral properties and formation rates to those found in similarly-aged limonene/O3 SOA. Similar chemical reaction processes of limononaldehyde (LA, C10H16O2) and pinonaldehyde (PA, C10H16O2), the first-generation ozonolysis products in the oxidation of limonene and α-pinene, respectively, were also studied, but the resulting products did not exhibit light absorption properties of brown carbon, suggesting that the unique molecular structure of KLA produces visible-light-absorbing compounds. The KLA/NH4+ and KLA/GLY reactions produce water-soluble, hydrolysis-resilient chromophores with high mass absorption coefficients (MAC = 2000-4000 cm2 g-1) at λ ~ 500 nm, precisely at the maximum of the solar emission spectrum. Liquid chromatography was used to isolate the light-absorbing fraction, and UV-Vis, FTIR, NMR and high-resolution mass spectrometry (HR-MS) techniques were used to investigate the structures and chemical properties of the light-absorbing compounds. The KLA browning reaction generates a diverse mixture of light-absorbing compounds, with the majority of the observable products containing 1-4 units of KLA and 0-2 nitrogen atoms. Based on the HR-MS product distribution, conjugated aldol condensates, secondary imines (Schiff bases), and N-heterocycles like pyrroles may contribute in varying degree to the light-absorbing properties

  6. Studies on the immune response and preparation of antibodies against a large panel of conjugated neurotransmitters and biogenic amines: specific polyclonal antibody response and tolerance.

    Science.gov (United States)

    Huisman, Han; Wynveen, Paul; Setter, Peter W

    2010-02-01

    We described the production and characterization of antibodies against three important groups of neuro-active haptens, e.g., neurotransmitters and biogenic amines. First, from the tryptophane metabolic pathway: tryptamine, serotonin, 5-hydroxy-indole acetic acid, and melatonin. Secondly, the tyrosine metabolic pathway: tyramine, dopamine, dihydroxyphenyl acetic acid, and norepinephrine. Thirdly, antibodies against excitatory and inhibitory neurotransmitters: glycine, glutamate, glutamine, and GABA. Immunogenic conjugates were prepared after linking haptens to carrier proteins. Most antibodies displayed high specificity against corresponding neuro-active haptens conjugated in vitro and in situ in biological specimens, but not to closely related conjugated metabolites, precursors, pharmaceuticals, agonists, antagonists, or free neuro-active haptens. Conjugated norepinephrine was highly tolerant in different animal species and produced incidentally a short specific antibody response.

  7. Relationships linking primary production, sea ice melting, and biogenic aerosol in the Arctic

    Science.gov (United States)

    Becagli, S.; Lazzara, L.; Marchese, C.; Dayan, U.; Ascanius, S. E.; Cacciani, M.; Caiazzo, L.; Di Biagio, C.; Di Iorio, T.; di Sarra, A.; Eriksen, P.; Fani, F.; Giardi, F.; Meloni, D.; Muscari, G.; Pace, G.; Severi, M.; Traversi, R.; Udisti, R.

    2016-07-01

    This study examines the relationships linking methanesulfonic acid (MSA, arising from the atmospheric oxidation of the biogenic dimethylsulfide, DMS) in atmospheric aerosol, satellite-derived chlorophyll a (Chl-a), and oceanic primary production (PP), also as a function of sea ice melting (SIM) and extension of the ice free area in the marginal ice zone (IF-MIZ) in the Arctic. MSA was determined in PM10 samples collected over the period 2010-2012 at two Arctic sites, Ny Ålesund (78.9°N, 11.9°E), Svalbard islands, and Thule Air Base (76.5°N, 68.8°W), Greenland. PP is calculated by means of a bio-optical, physiologically based, semi-analytical model in the potential source areas located in the surrounding oceanic regions (Barents and Greenland Seas for Ny Ålesund, and Baffin Bay for Thule). Chl-a peaks in May in the Barents sea and in the Baffin Bay, and has maxima in June in the Greenland sea; PP follows the same seasonal pattern of Chl-a, although the differences in absolute values of PP in the three seas during the blooms are less marked than for Chl-a. MSA shows a better correlation with PP than with Chl-a, besides, the source intensity (expressed by PP) is able to explain more than 30% of the MSA variability at the two sites; the other factors explaining the MSA variability are taxonomic differences in the phytoplanktonic assemblages, and transport processes from the DMS source areas to the sampling sites. The taxonomic differences are also evident from the slopes of the correlation plots between MSA and PP: similar slopes (in the range 34.2-36.2 ng m-3of MSA/(gC m-2 d-1)) are found for the correlation between MSA at Ny Ålesund and PP in Barents Sea, and between MSA at Thule and PP in the Baffin Bay; conversely, the slope of the correlation between MSA at Ny Ålesund and PP in the Greenland Sea in summer is smaller (16.7 ng m-3of MSA/(gC m-2 d-1)). This is due to the fact that DMS emission from the Barents Sea and Baffin Bay is mainly related to the MIZ

  8. Nature and origin of the resistant carbonaceous polymorphs involved the fossilization of biogenic soil-aggregates

    Science.gov (United States)

    Courty, M.-A.

    2012-04-01

    The rare occurrence of organic-rich surface horizons in soil archives is widely accepted to resulting from their rapid degradation. We intend here to further elucidate how pedogenic signatures that initially formed at the soil surface could resist over long timescales to burial processes. We focus on the structural evolution of the biogenic soil aggregates that is controlled by the complex interaction of bioturbation, root colonization, microbial decomposition, chemical weathering and physical processes. The nature and origin of carbonaceous components that could possibly contribute to the long term preservation of biogenic soil-aggregates is particularly examined. The study is based on the comparison of pedogenic aggregated microfacies from present-day situations and the ones encountered in soil archives from contrasting edaphic conditions: Arctic Holocene soils from Spitsbergen, hyper-arid soils from the Moche valley (Peru), Holocene semi-arid Mediterranean soils from Northern Syria, late Pleistocene paleosols from lake Mungo (South Wales Australia) and late Pleistocene paleosols from the Ardeche valley (France). The assemblage and composition of biogenic soil-aggregated horizons has been characterized under the binocular microscope and in thin sections. The basic components have been separated by water sieving. A typology of carbonaceous polymorphs and associated composite materials has been established under the binocular. They have been characterized by SEM-EDS, Raman spectrometry, X-ray diffraction and TEM. The comparative study shows that all the biogenic soil-aggregates from the soil archives contain a high amount of similar exotic components that contrast from the parent materials by their fresh aspect and their hydrophobic properties. This exotic assemblage comprises various types of aliphatic carbonaceous polymorphs (filaments, agglutinates, spherules) and aromatic ones (vitrous char, graphite), carbon cenospheres, fine grained sandstones and rock clasts

  9. European Biogenic Volatile Organic Compound emissions estimate using MEGAN v2.10

    Science.gov (United States)

    Dawoud, M.; Pozzoli, L.; Unal, A.; Kindap, T.; Poupkou, A.; Katragou, E.; Melas, D.

    2013-12-01

    Biogenic emissions estimations are essential to obtain a comprehensive understanding of both anthropogenic and biogenic contributions of the emissions. In this paper we have calculated the Biogenic Volatile Organic Compound (BVOC) emissions from vegetation over Europe using the newly developed Model of Emissions of Gases and Aerosols from Nature version 2.10 (MEGAN2.10). We performed a simulation of the entire year 2008 for a domain covering all Europe at a resolution of 30 x 30 km. The meteorological fields needed to calculate the BVOC emissions (surface temperature and shortwave radiation) were provided by a WRFv3.3 simulation (driven by NCEP/FNL global reanalysis data at 1° x 1°) and interfaced to MEGAN with MCIPv3.6. We used the global dataset provided with the MEGAN2.10 model containing the Plant Functional Types (PFT, at 0.5° x 0.5°), Leaf Area Indices (LAI, at 30s resolution) and Emission Factors (EF, at 0.01° x 0.01°). The motivation behind this study is to quantify the biogenic emissions as calculated from the new version of MEGAN over Europe for the entire annual cycle, and in second step to quantify the impact of biogenic emissions on air quality, using the Community Multiscale Air Quality model (CMAQ). Isoprene emissions comprise about half of the total global biogenic volatile organic compound (BVOC) estimated using MEGAN2.10, while all Terpenes comprise about 18% of the estimated total global BVOC emissions. Our simulations showed that Isoprene emissions are ranging from 10.7 Gg/month in December to 6572.8 Gg/month over Europe in July, while Terpenes emissions range from 38 Gg/month in January and 1598.23 Gg/month in July. Around 15 Tg/year and 5 Tg/year are estimated as total annual emissions of Isoprene and Terpenes, respectively. In comparison with a previous study using the Natural Emission Model (NEMO), for the same period and the similar domain and resolution, for July we found 70% higher Isoprene emissions and 30% lower Terpenes emissions

  10. Determination of the Three-Dimensional Morphology of ALH84001 and Biogenic MV-1 Magnetite: Comparison of Results from Electron Tomography and Classical Transmission Electron Microscopy

    Science.gov (United States)

    Thomas-Keprta, Kathie L.; Clemett, Simon J.; Schwartz, Cindy; Morphew, Mary; McIntosh, J. Richard; Bazylinski, Dennis A.; Kirschvink, Joseph L.; Wentworth, Susan J.; McKay, David S.; Vali, Hojatollah

    2004-01-01

    Dated at approximately 3.9 billion years of age, carbonate disks, found within fractures of the host rock of Martian meteorite ALH84001, have been interpreted as secondary minerals that formed at low temperature in an aqueous medium. Heterogeneously distributed within these disks are magnetite nanocrystals that are of Martian origin. Approximately one quarter of these magnetites have morphological and chemical similarities to magnetite particles produced by magnetotactic bacteria strain MV-1, which are ubiquitous in aquatic habitats on Earth. Moreover, these types of magnetite particles are not known or expected to be produced by abiotic means either through geological processes or synthetically in the laboratory. The remaining three quarters of the ALH84001 magnetites are likely products of multiple processes including, but not limited to, precipitation from a hydrothermal fluid, thermal decomposition of the carbonate matrix in which they are embedded, and extracellular formation by dissimilatory Fe-reducing bacteria. We have proposed that the origins of magnetites in ALH84001 can be best explained as the products of multiple processes, one of which is biological. Recently the three-dimensional (3-D) external morphology of the purported biogenic fraction of the ALH84001 magnetites has been the subject of considerable debate. We report here the 3-D geometry of biogenic magnetite crystals extracted from MV-1 and of those extracted from ALH84001 carbonate disks using a combination of high resolution classical and tomographic transmission electron microscopy (TEM). We focus on answering the following questions: (1) which technique provides adequate information to deduce the 3-D external crystal morphology?; and, (2) what is the precise 3-D geometry of the ALH84001 and MV-1 magnetites?

  11. Biogenic smectite clay formation in subsurface granitic environments

    Science.gov (United States)

    Tuck, V.; Edyvean, R.; West, J.; Bateman, K.; Coombs, P.; Milodowski, A.

    2003-04-01

    groundwater through the column. There was also evidence of possible bio-surfactant activity causing the mobilization and trapping of fine-grained materials (<5µm) which had been produced during the crushing process and which had originally adhered to the larger grain surfaces. In contrast, the columns containing either no bacteria or only the sulphate-reducing bacteria D. aespoeensis showed no evidence of clay or biofilament formation, and little evidence of mobilization of fine particulates.

  12. Deciphering Carbon Isotope Excursions in Separated Biogenic and Diagenetic Carbonates

    Science.gov (United States)

    Hermoso, M.; Minoletti, F.; Hesselbo, S.; Jenkyns, H.; Rickaby, R.; Diester-Haass, L.; Delsate, D.

    2008-12-01

    The long-term evolution of the carbon-isotope ratio in the sedimentary archive is classically linked with changes in primary productivity and organic matter burial. There have been sudden and pronounced shifts, so-called Carbon Isotope Excursions (CIEs) in the long-term trends as evidenced by synchronous shifts from various basins. These geochemical perturbations may have various explanations such as changes of the efficiency of the carbon sink; sudden infusion of isotopically-light carbon into the Ocean-Atmosphere system; or advection of 12C-rich source from bottom water in a stratified water column. Beside the record of primary changes in seawater chemistry, a possible diagenetic overprint may also mime such CIEs in the sedimentary record. The aim of this contribution is to illustrate through three critical intervals (the Early Toarcian, the K-P boundary and the Mid-Miocene Montery Event) how the various micron-sized sedimentary particles specifically record these CIEs, which are respectively associated with major paleoceanographical events. New techniques for getting monotaxic calcareous nannofossil assemblages from the sediment (Minoletti et al., accepted) enable the isotopic measurement at various depths within the surface water and from bottom water by analyzing early diagenetic precipitations (rhombs and micarbs). The integration of these high-resolution isotopic signals in terms of amplitudes affords to recognize diagenetic artifacts in some sections displaying coeval decrease in the carbonate content. For both Early Toarcian and K-P events, corroborative records of CIE records in both primary calcite and bottom water carbonate indicate a global C-isotope perturbation of the water column. For the Monterey event, the evolution of calcareous nannoplankton and the foraminifera isotopic records are in overall agreement, but in detail, the coccolith-discoaster and foraminifer ratio in the sediment, related to environmental changes, is likely to produce isotopic

  13. Physiology and Genetics of Biogenic Methane-Production from Acetate

    Energy Technology Data Exchange (ETDEWEB)

    Sowers, Kevin R

    2013-04-04

    Biomass conversion catalyzed by methanogenic consortia is a widely available, renewable resource for both energy production and waste treatment. The efficiency of this process is directly dependent upon the interaction of three metabolically distinct groups of microorganisms; the fermentative and acetogenic Bacteria and the methanogenic Archaea. One of the rate limiting steps in the degradation of soluble organic matter is the dismutation of acetate, a predominant intermediate in the process, which accounts for 70 % or more of the methane produced by the methanogens. Acetate utilization is controlled by regulation of expression of carbon monoxide dehydrogensase (COdh), which catalyzes the dismutation of acetate. However, physiological and molecular factors that control differential substrate utilization have not been identified in these Archaea. Our laboratory has identified sequence elements near the promoter of the gene (cdh) encoding for COdh and we have confirmed that these sequences have a role in the in vivo expression of cdh. The current proposal focuses on identifying the regulatory components that interact with DNA and RNA elements, and identifying the mechanisms used to control cdh expression. We will determine whether expression is controlled at the level of transcription or if it is mediated by coordinate interaction of transcription initiation with other processes such as transcription elongation rate and differential mRNA stability. Utilizing recently sequenced methanosarcinal genomes and a DNA microarray currently under development genes that encode regulatory proteins and transcription factors will be identified and function confirmed by gene disruption and subsequent screening on different substrates. Functional interactions will be determined in vivo by assaying the effects of gene dosage and site-directed mutagenesis of the regulatory gene on the expression of a cdh::lacZ operon fusion. Results of this study will reveal whether this critical

  14. MICROALGAE AS TOCOPHEROL PRODUCERS

    Directory of Open Access Journals (Sweden)

    V. M. Mokrosnop

    2014-04-01

    Full Text Available Microalgae are able to accumulate considerable amounts of tocopherols (up to 4 mg/g dry weight. The content of α-tocopherol to plant oils is low, whereas microalgae contain up to 97% of the tocochromanols that provides high bioactivity. The data about the content of tocopherols in eukaryotic microalgae Dunaliella tertiolecta, Nannochloropsis oculata, Isochrysis galbana, Euglena gracilis, Tetraselmis suecica, Diacronema vlkianum, as well as in the cyanobacterium Spirulina platensis are given in the paper. The largest amounts of tocopherols are synthesized by Euglena gracilis cells at mixotrophic cultivation. The level of tocopherols in microalgae depends on cultivation conditions. Two-stage biotech cultivation techniques, limiting nutrition in some biogenic elements, the introduction of exogenous carbon sources are used to increase the yield of tocopherol from microalgae. The approaches to the genetic transformation of plants leading to higher content of active vitamin E are rewieved as well.

  15. Electrolyte-promoted demineralization of biogenic, vitreous, and crystalline silica: A density functional investigation

    Science.gov (United States)

    Dove, P. M.; Wallace, A. F.; Gibbs, G. V.

    2007-12-01

    The dissolution of amorphous and crystalline varieties of SiO2 is an integral part of the global biogeochemical cycle of silicon. Nanoparticulate biogenic silica produced by marine phytoplankton and terrestrial plants are of particular interest because their enhanced reactivity and abundance make them important sources and sinks of dissolved silicon in natural environments. Recent experimental results on (100) surfaces of quartz show that the dominant dissolution mechanism in simple H2O solutions is by retreat of Q2 groups along step edges. In the presence of electrolytes, rates are accelerated by up to 100X in the presence by a crossover in the dominant dissolution mechanism to nucleation of vacancy islands at Q3 terminated species (Dove et al., PNAS, 2005). While the control of surface coordination in reactivity is clear, the molecular pathway by which electrolytes induce dissolution by a nucleated process remains poorly understood. The results of previous ab initio investigations of Si-O bond hydrolysis by water have demonstrated that the reaction proceeds through the dissociative adsorption of H2O at the silica surface, resulting in the formation of a pentacoordinated Si transition state, followed by the transfer of one of the water bound hydrogen atoms to a bridging oxygen in the SiO2 bonded network, and breakage of the Si-O bond. Assuming a similar reaction path, the specific effects of hydrated group II metal cations (Mg2+, Ca2+, Sr2+, Ba2+) on the energetics of Si-O bond hydrolysis have been investigated with density functional methods (B3LYP) and a relatively large neutral silica cluster (H8Si6O16). Reactant, product, and transition states for Q3 to Q2 hydrolysis in the presence and absence of the afore-mentioned cations have been determined with all electron (6-31G(d)) and effective core potential (SDDALL) Gaussian basis sets. The free energy of activation for Q3 to Q2 Si-O bond hydrolysis was determined to be approximately 5 kJ/mol lower for Ca2+ than Mg

  16. Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-02-01

    The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines.

  17. CHANGES IN COUNTS OF MICROORGANISMS AND BIOGENIC AMINES PRODUCTION DURING THE MANUFACTURE OF FERMENTED SAUSAGES POLIČAN

    Directory of Open Access Journals (Sweden)

    Libor Kalhotka

    2012-10-01

    Full Text Available Poličan is classic raw fermented sausage with low acidity. Dry fermented sausages Poličan were used for the analysis and drawn once a week during production from ripening chambers of meat-packing plants. Those sausages ripened for 35 days under controlled temperature and humidity conditions. The aim of this article is to evaluate microorganisms accompanying ripening of fermented sausages Poličan and characterize relationships between activity of microorganisms and content of biogenic amines. Lactic acid bacteria are the most important group of microorganisms. Their counts are relatively high already at the beginning of ripening - about 106 CFU.g-1. During the first week of ripening, their numbers increased to 107 CFU.g-1 and has not changed much further. Due to the minimal counts of coliform bacteria and micromycetes at the end of ripening, both series of these products can be considered as good and safe. In freshly made sausages, the amount of biogenic amines was low. Spermidine, spermine and tyramine were quantitatively the most important. During ripening, the content of biogenic amines was increasing. Significant difference in biogenic amines between I. and II. series was found only for tyramine which was detected in difference exceeding 100 mg.kg-1 at the end of ripening. Sausages from II. series with high levels of tyramine may present a risk for sensitive individuals. Due to low levels of biogenic amines, other samples may be regarded as unproblematic.

  18. Tethered balloon measurements of biogenic volatile organic compounds at a Boreal forest site

    Directory of Open Access Journals (Sweden)

    C. Spirig

    2004-01-01

    Full Text Available Measurements of biogenic volatile organic compounds (VOCs were performed at Hyytiälä, a Boreal forest site in Southern Finland as part of the OSOA (origin and formation of secondary organic aerosol project in August 2001. At this site, frequent formation of new particles has been observed and the role of biogenic VOCs in this process is still unclear. Tethered balloons served as platforms to collect VOC samples within the planetary boundary layer at heights up to 1.2 km above ground during daytime. Mean mixed layer concentrations of total monoterpenes varied between 10 and 170 pptv, with a-pinene, limonene and D3-carene as major compounds, isoprene was detected at levels of 2-35 pptv. A mixed layer gradient technique and a budget approach are applied to derive surface fluxes representative for areas of tens to hundreds of square kilometres. Effects of spatial heterogeneity in surface emissions are examined with a footprint analysis. Depending on the source area considered, mean afternoon emissions of the sum of terpenes range between 180 and 300 mg m-2 h-1 for the period of 2-12 August 2001. Surface fluxes close to Hyytiälä were higher than the regional average, and agree well with mean emissions predicted by a biogenic VOC emission model. Total rates of monoterpene oxidation were calculated with a photochemical model. The rates did not correlate with the occurrence of new particle formation, but the ozone pathway was of more importance on days with particle formation. Condensable vapour production from the oxidation of monoterpenes throughout the mixed layer can only account for a fraction of the increase in aerosol mass observed at the surface.

  19. Chemistry of rain events in West Africa: evidence of dust and biogenic influence in convective systems

    Directory of Open Access Journals (Sweden)

    K. Desboeufs

    2010-10-01

    Full Text Available This paper documents the chemical composition of 7 rain events associated with mesoscale convective systems sampled at the supersite of Banizoumbou, Niger, during the first special observation periods (June–July 2006 of the African Monsoon Multidisciplinary Analyses (AMMA experiment. Time-resolved rain sampling was performed in order to discriminate the local dust scavenged at the beginning of rain event from the aerosol particles incorporated in the cloud at the end of the rain. The total elemental composition is dominated by Al, Si, Fe and Ca, indicating a high influence of dust and limited marine or anthropogenic contribution. After the aerosol wash-out, the elemental concentrations normalized to Al and the microscopic observations of diatoms, a tracer of the Bodélé depression, both indicate that the total elemental composition of rainwater is controlled by dust originating from North-eastern Saharan sources and probably incorporated in the convective cloud from the Harmattan layer. The low variability of the rain composition over the measurement period indicates a regional and temporal homogeneity of dust composition in the Harmattan layer. In the dissolved phase, the dominant anions are nitrate (NO3, sulphate (SO42− and chloride (Cl. However, between June and July we observe an increasing contribution of the organic anions (formate, acetate, oxalate associated with biogenic emissions to the total ion composition. These results confirm the large influence of biogenic emissions on the rain composition over Sahel during the wet season. The paper concludes on the capacity of mesoscale convective systems to carry simultaneously dust and biogenic compounds originating from different locations and depose them jointly. It also discusses the potential biogeochemical impact of such a phenomenon.

  20. Soil biogenic emissions of nitric oxide from a semi-arid savanna in South Africa

    Science.gov (United States)

    Feig, G. T.; Mamtimin, B.; Meixner, F. X.

    2008-12-01

    Soils of arid and semi-arid ecosystems are important biogenic sources of atmospheric nitric oxide (NO), however, there is still a shortage of measurements from these systems. Here we present the results of a laboratory study of the biogenic emission of NO from four different landscape positions of the Kruger National Park (KNP), a large conservation area in a semi-arid region of South Africa. Results show that the highest net potential NO fluxes come from the low lying (footslope) landscape regions, which have the largest nitrogen stocks and highest rates of nitrogen input into the soil. Net potential NO fluxes from midslope and crest regions were considerably lower. The maximum release of NO occurred at fairly low soil moisture contents of 10%-20% water filled pore space. Using soil moisture and temperature data obtained in situ at the Kruger National Park flux tower site, net potential NO fluxes obtained in the laboratory were converted to field fluxes for each of the four landscape positions for the period 2003 to 2005. The highest field NO flux is from footslope positions, during each of these years and emissions ranged from 1.5-8.5 kg ha a (in terms of mass of nitrogen). Remote sensing and Geographic Information Systems techniques were used to up-scale field NO fluxes on a regional basis indicating that the highest emissions occurred from the midslope positions, due to their large geographical extent in the considered research area. Emissions for the KNP Skukuza land type (56 000 ha) ranged from 20×103 kg in 2004 to 34×103 kg in 2003. The importance of landscape characteristics in the determination of regional biogenic NO soil emission is emphasized.

  1. Magnetic Dinner Salads: The Role of Biogenic Magnetite in Cryopreservation for Common Food Plants

    Science.gov (United States)

    Chaffee, T. M.; Kirschvink, J. L.; Kobayashi, A. K.

    2015-12-01

    Biogenically-precipitated magnetite has been found in organisms ranging from Bacteria, single-celled protists, and many of the animal phyla, where its major function is navigation and magnetoreception. To date there is but a single report of biogenic magnetite in plants (essentially, magnetoferritin), and that is in common grass (Festuca species, from Gajdardziska-Josifovska et. al. doi:10.1127/0935-1221/2001/0013/0863). Recent developments in cryopreservation suggest that ~ 1 mT, ~ 10 Hz oscillating magnetic fields can drastically reduce ice nucleation during freezing, promote supercooling, and minimize cellular damage in living tissues (e.g., Kaku et al., doi: 10.1016/j.cryobiol.2012.02.001). Kobayashi & Kirschvink (2014, doi:10.1016/j.cryobiol.2013.12.002) suggest that biogenic magnetite crystals could be the nucleating site for damaging ice crystals, and that they would be driven magneto-mechanically to rotate in those oscillating fields which could inhibit the ice crystal nucleation process. This prompted our investigation into the magnetite content of ordinary fruit and vegetable food products, as knowledge of the natural levels of biogenic magnetite in the human food supply could guide the selection of which foods might work for this type of cryopreservation. Our study involved a range of common foods including avocados, bananas, garlic, and apples. Samples were prepared in a clean lab environment kept free of contaminant particles, and subjected to a variety of standard rock-magnetic tests including IRM and ARM acquisition, and the corresponding Af demagnetization, on a standard 2G™ SRM. Results are consistent with moderately interacting single-domain magnetite (see figure), with moderate inter-particle interaction effects. Typical magnetite concentrations in these samples are in the range of .1 to 1 ng/g for room temperature samples, increasing to the range of 1-10 ng/g when measured frozen (to inhibit thermal rotation of small particles and clumps). If

  2. Synthetic and biogenic magnetite nanoparticles for tracking of stem cells and dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Sebastian [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Fernandes, Fabiana [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Department of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Sanroman, Laura [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Hodenius, Michael [Institute for Biomedical Engineering and Helmholtz Institute for Biomedical Engineering, Department of Applied Medical Engineering, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Lang, Claus [Department of Microbiology, Ludwig-Maximillians-University of Munich, Maria-Ward-Str. 1a, 80638 Munich (Germany); Himmelreich, Uwe [In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Gleueler Str. 50, 50931 Cologne (Germany); Biomedical NMR Unit, MoSAIC, Faculty of Medicine, KU Leuven, Onderwijs en Navorsing 1, bus 505, 3000 Leuven (Belgium); Schmitz-Rode, Thomas [Institute for Biomedical Engineering and Helmholtz Institute for Biomedical Engineering, Department of Applied Medical Engineering, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Schueler, Dirk [Department of Microbiology, Ludwig-Maximillians-University of Munich, Maria-Ward-Str. 1a, 80638 Munich (Germany); Hoehn, Mathias [In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Gleueler Str. 50, 50931 Cologne (Germany)] (and others)

    2009-05-15

    Accurate delivery of cells to target organs is critical for success of cell-based therapies with stem cells or immune cells such as antigen-presenting dendritic cells (DC). Labeling with contrast agents before implantation provides a powerful means for monitoring cellular migration using magnetic resonance imaging (MRI). In this study, we investigated the uptake of fully synthesized or bacterial magnetic nanoparticles (MNPs) into hematopoietic Flt3{sup +} stem cells and DC from mouse bone marrow. We show that (i) uptake of both synthetic and biogenic nanoparticles into cells endow magnetic activity and (ii) low numbers of MNP-loaded cells are readily detected by MRI.

  3. Reduction of Biogenic Amines during Miso Fermentation by Lactobacillus plantarum as a Starter Culture.

    Science.gov (United States)

    Lee, Yi-Chen; Kung, Hsien-Feng; Huang, Ya-Ling; Wu, Chien-Hui; Huang, Yu-Ru; Tsai, Yung-Hsiang

    2016-09-01

    Lactobacillus plantarum D-103 isolated from a miso product that possesses amine-degrading activity was used as a starter culture in miso fermentation (25°C for 120 days) in this study. The salt content in control samples (without starter culture) and inoculated samples (inoculated with L. plantarum D-103) remained constant at 10.4% of the original salt concentration throughout fermentation, whereas the pH value decreased from 6.2 to 4.6 during fermentation. The inoculated samples had significantly lower (P culture with amine-degrading activity in miso products was effective in reducing the accumulation of biogenic amines.

  4. Structural distortion of biogenic aragonite in strongly textured mollusc shell layers

    Energy Technology Data Exchange (ETDEWEB)

    Chateigner, D., E-mail: daniel.chateigner@ensicaen.f [CRISMAT-ENSICAEN, Universite de Caen Basse-Normandie, 6 Bd. M. Juin, 14050 Caen (France); Ouhenia, S. [CRISMAT-ENSICAEN, Universite de Caen Basse-Normandie, 6 Bd. M. Juin, 14050 Caen (France); Lab. De Physique, Faculte des Sciences Exactes, Bejaia 06000 (Algeria); Krauss, C. [CRISMAT-ENSICAEN, Universite de Caen Basse-Normandie, 6 Bd. M. Juin, 14050 Caen (France); Belkhir, M. [Lab. De Physique, Faculte des Sciences Exactes, Bejaia 06000 (Algeria); Morales, M. [CIMAP-ENSICAEN, Universite de Caen Basse-Normandie, 6 Bd. M. Juin, 14050 Caen (France)

    2010-02-15

    The stabilisation of strong textures in mollusc shells has for long been a strong drawback towards precise structural determinations of these natural biocomposites. We demonstrate here on several crossed lamellar and nacre layers from two gastropods (Charonia lampas lampas and Haliotis tuberculata tuberculata) and one bivalve (Pinctada maxima), that on real specimens (without grinding or specific preparation), the textural information can be used efficiently for precise structural determination of the biogenic aragonite. This is done through the combination of orientation distribution function and cyclic Rietveld refinements on several hundreds to thousands of diffractions diagrams.

  5. Elevated Glyoxal Concentrations over the Eastern Equatorial Pacific: A Direct Biogenic Source?

    Science.gov (United States)

    Zhang, R.; Wang, Y.; Lerot, C.

    2014-12-01

    Elevated atmospheric glyoxal (CHOCHO) was observed over the eastern equatorial Pacific by satellite and ship measurements. We investigated the source contributions through inverse modeling using GOME-2 observations (2007-2012) and the GEOS-Chem model. The observed high glyoxal to HCHO column ratio over the region indicates the potential presence of a direct source of glyoxal rather than secondary production. A bimodal seasonal cycle of glyoxal concentrations was found, providing further evidence for a biogenic origin of glyoxal emission. The estimate of the primary glyoxal emission over the eastern equatorial Pacific is 20-40Tg/yr, which is comparable to the previous estimate of the global continential glyoxal emission.

  6. Uraniferous minerals - uraninite and derived or related uraniferous minerals; Mineraux uraniferes - uraninite et mineraux uraniferes derives ou associes

    Energy Technology Data Exchange (ETDEWEB)

    Lebrun, P.; Cesbron, F.; Le Cleac' h, J.M.; Lebocey, J.

    2009-07-01

    This special issue of 'Mineraux et Fossiles' journal (no.28) proposes a real trip in the uranium world with the exception of the industrial and military applications. The book comprises 6 chapters fully illustrated with figures and photos of minerals dealing with: 1 - a brief history of uranium (including radioactivity); 2 - crystallo-chemistry of some uranium minerals; 3 - uranium minerals with a presentation of the most important species ('remarkable' species); 4 - classification of uranium deposits; 5 - most famous uranium deposits which played an important role in the development of nuclear industry (Jachymov deposit in Czech Republic, Shinkolobwe in Katanga, Oklo in Gabon etc); 6 - uranium usages, in particular in glass and ceramics coloring and in geochronology. (J.S.)

  7. Biogenic amine formation and nitrite reactions in meat batter as affected by high-pressure processing and chilled storage.

    Science.gov (United States)

    Ruiz-Capillas, C; Aller-Guiote, P; Carballo, J; Colmenero, F Jiménez

    2006-12-27

    Changes in biogenic amine formation and nitrite depletion in meat batters as affected by pressure-temperature combinations (300 MPa/30 min/7, 20, and 40 degrees C), cooking process (70 degrees C/30 min), and storage (54 days/2 degrees C) were studied. Changes in residual nitrite concentration in raw meat batters were conditioned by the temperature and not by the pressure applied. Cooking process decreased (P batters. High-pressure processing conditions had no effect on the rate of residual nitrite loss throughout the storage. The application of high pressure decreased (P < 0.05) the concentration of some biogenic amines (tyramine, agmatine, and spermine). Irrespective of the high processing conditions, generally, throughout storage biogenic amine levels did not change or increased, although quantitatively this effect was not very important.

  8. Biogenic Fe(III) minerals lower the efficiency of iron-mineral-based commercial filter systems for arsenic removal.

    Science.gov (United States)

    Kleinert, Susanne; Muehe, Eva M; Posth, Nicole R; Dippon, Urs; Daus, Birgit; Kappler, Andreas

    2011-09-01

    Millions of people worldwide are affected by As (arsenic) contaminated groundwater. Fe(III) (oxy)hydroxides sorb As efficiently and are therefore used in water purification filters. Commercial filters containing abiogenic Fe(III) (oxy)hydroxides (GEH) showed varying As removal, and it was unclear whether Fe(II)-oxidizing bacteria influenced filter efficiency. We found up to 10(7) Fe(II)-oxidizing bacteria/g dry-weight in GEH-filters and determined the performance of filter material in the presence and absence of Fe(II)-oxidizing bacteria. GEH-material sorbed 1.7 mmol As(V)/g Fe and was ~8 times more efficient than biogenic Fe(III) minerals that sorbed only 208.3 μmol As(V)/g Fe. This was also ~5 times more efficient than a 10:1-mixture of GEH-material and biogenic Fe(III) minerals that bound 322.6 μmol As(V)/g Fe. Coprecipitation of As(V) with biogenic Fe(III) minerals removed 343.0 μmol As(V)/g Fe, while As removal by coprecipitation with biogenic minerals in the presence of GEH-material was slightly less efficient as GEH-material only and yielded 1.5 mmol As(V)/g Fe. The present study thus suggests that the formation of biogenic Fe(III) minerals lowers rather than increases As removal efficiency of the filters probably due to the repulsion of the negatively charged arsenate by the negatively charged biogenic minerals. For this reason we recommend excluding microorganisms from filters (e.g., by activated carbon filters) to maintain their high As removal capacity.

  9. Influence of ripening time on the amount of certain biogenic amines in rind and core of cow milk Livno cheese

    Directory of Open Access Journals (Sweden)

    Antonela Marijan

    2014-09-01

    Full Text Available Determining the levels of biogenic amines in cheese except that it has significance for determining the nutritional value and hygienic accuracy, cheese as food can be used as a parameter to evaluate the conditions of production and/or ripening of products, and particularly in the selection of bacterial cultures. The purpose of this paper was to determine the effect of the ripening process on the amount of biogenic amines in cheese. For this purpose were conducted physico-chemical analysis, determination of biogenic amines and microbiological analysis. During the process of ripening Livno cheese from three different batches was taken one cheese from prime day and 9th, 20th, 29th, 50th, 60th and 105th day. From each cheese two samples were taken, one from the middle and one from the cheese rind. During 105th day of ripening Livno cheese, the presence of triptamin, ß-feniletlamine, putrescine, cadaverine, histamine, tyramine, spermine and spermidine were determinated. The maximum total values of searched biogenic amines were found 105th day, in the middle 184.13 mg/kg and 76.26 mg/kg in the rind of cheese. With an indication that the largest share of value rep¬resent histamine with 43.9 % and tyramine with 38.2 % in the middle, respectively histamine with 31.6 % and tyramine with 31.5 % in the rind of cheese. The values of putrescine and spermine were in small ranges and they are not identified in all samples. The values of histamine and tyramine are almost a third more at 105th than 60th day. There was a significant difference between the middle and the rind of cheese in the values of biogenic amines. Correlation between biogenic amines and microorganisms has not been determined.

  10. Insights into the optical and anti-bacterial properties of biogenic PbSe quantum rods

    Directory of Open Access Journals (Sweden)

    Jaya Mary Jacob

    2016-07-01

    Full Text Available The detailed optical properties of lead selenide (PbSe quantum rods biosynthesized in marine Aspergillus terreus were apprehended theoretically using ab initio calculations based on the experimental absorption spectrum. These studies indicate that the absorption coefficient of the biosynthesized PbSe quantum rods increases linearly with incident photon energies. The variation of other optical constants like extinction coefficient, refractive index and reflectance was comparable to that of the chemically synthesized counterparts. Further, the high dielectric constant and remarkable fluorescence of the biogenic PbSe quantum rods pronounce their application in opto-electronic devices in the Near Infra-Red and Ultraviolet spectral regime. The biosynthesized PbSe quantum rods were also found to possess appreciable anti-bacterial activity against various gram positive and gram negative bacterial species thus enhancing the relevance of the same for practical utility. Based on these results it can be concluded that biogenic PbSe quantum rods can be envisaged as potential candidates for bio-imaging, bio-sensing and other photo-voltaic applications.

  11. Determination of biogenic amines in beer and wine by capillary electrophoresis-tandem mass spectrometry.

    Science.gov (United States)

    Daniel, Daniela; Dos Santos, Vagner Bezerra; Vidal, Denis Tadeu Rajh; do Lago, Claudimir Lucio

    2015-10-16

    A capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) method for the simultaneous assessment of nine biogenic amines (spermine, spermidine, putrescine, cadaverine, histamine, phenylethylamine, tryptamine, tyramine, and urocanic acid) in commercial samples of beer and wine is introduced. The samples were submitted to a simple clean-up step with poly(vinylpolypyrrolidone) followed by filtration. Electrophoretic separation in a polyvinyl alcohol (PVA)-coated capillary using 0.5 mol L(-1) acetic acid (pH 2.5) as background electrolyte and detection by electrospray-tandem mass spectrometry was employed. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.996-0.999, and the limits of detection and limits of quantification were in the range of 1-2 μg L(-1) and 3-8 μg L(-1), respectively. The recovery values for samples spiked at three concentration levels (0.2, 0.5, and 1.0 mg L(-1)) ranged from 87 to 113% with standard deviation not greater than 5.8%. The use of a PVA-coated silica capillary allows suppressing the electroosmotic flow and, consequently, increasing of the separation efficiency. The method was successfully used to determine biogenic amines in commercial samples of beer and wine.

  12. Biogenic Aerosols Over the Amazon Basin: Optical Properties and Relationship With Elemental and Ionic Composition

    Science.gov (United States)

    Artaxo, P.; Martin, S. T.; Andreae, M. O.; Godoy, J. M.; Godoy, M. L.; Rizzo, L. V.; Paixao, M.

    2008-12-01

    We investigated the optical properties of natural biogenic aerosol particles over the central Amazon Basin near Manaus during the wet season in February and March 2008. The measurements were conducted as part of the AMAZE-08 (Amazonian Aerosol Characterization Experiment) sampling campaign. Light absorption was determined with the use of an Aethalometer and an MAAP (Multi Angle Absorption Photometer). Light scattering was measured with a 3 wavelength TSI nephelometer and an Ecotech nephelometer. The elemental composition was measured trough PIXE and IC. Single scattering albedo shows relatively low values varying from 0.86 to 0.95. Very low fine mode aerosol mass was measured, and coarse mode particles are responsible for a significant fraction of scattering and absorption. Sulfur was observed in very low concentrations, and most of the aerosol mass was organic. Long range transport of soil dust from Sahara were observed and reflected in the light scattering coefficient. Wavelength dependence of absorption indicates the strong influence of coarse mode aerosol. Aerosol optical thickness shows low values, but with significant single scattering albedo values, showing strong absorption properties of these biogenic aerosols. Size distribution measurements shows consistence with the scattering coefficients measured, if the coarse mode particles are taken into account.

  13. Validation of a Fluorescence Sensor Microtiterplate for Biogenic Amines in Meat and Cheese.

    Science.gov (United States)

    Khairy, Gasser M; Azab, Hassan A; El-Korashy, Sabry A; Steiner, Mark-Steven; Duerkop, Axel

    2016-09-01

    An optical sensor microtiterplate for quantitative analysis of the total content of biogenic amines (TAC) in meat and cheese was developed and validated for the first time. In the plate, a chameleon dye (Py-1) is embedded in a polymeric cocktail which is deposited on the bottom of the wells in a common microtiterplate. On reaction with biogenic amines (BAs), the fluorescence of Py-1 at 620 nm rapidly delivers a precise TAC. After 10 min incubation at 25 °C the determination of the TAC in various (real) samples is possible in high-throughput with a standard microplate reader. The optimized fluorescence method was validated for linearity, sensitivity, accuracy, precision (intraday and inter day repeatability) and recovery using histamine (HIS) as a representative BA. The sensor microtiterplate was successfully applied to quantitatively analyze the TAC in 10 real samples of cheese and meat obtained from various Egyptian markets. The TAC of these real samples obtained by the sensor microtiterplate was validated against the contents of BAs obtained by GC-MS at various times of storage. The data of the sensor microtiterplate agreed well with those of GC-MS. This demonstrates that the sensor microtiterplate is a reliable screening tool for the degradation status of food samples.

  14. Large increases in Arctic biogenic volatile emissions are a direct effect of warming

    Science.gov (United States)

    Kramshøj, Magnus; Vedel-Petersen, Ida; Schollert, Michelle; Rinnan, Åsmund; Nymand, Josephine; Ro-Poulsen, Helge; Rinnan, Riikka

    2016-05-01

    Biogenic volatile organic compounds are reactive gases that can contribute to atmospheric aerosol formation. Their emission from vegetation is dependent on temperature and light availability. Increasing temperature, changing cloud cover and shifting composition of vegetation communities can be expected to affect emissions in the Arctic, where the ongoing climate changes are particularly severe. Here we present biogenic volatile organic compound emission data from Arctic tundra exposed to six years of experimental warming or reduced sunlight treatment in a randomized block design. By separately assessing the emission response of the whole ecosystem, plant shoots and soil in four measurements covering the growing season, we have identified that warming increased the emissions directly rather than via a change in the plant biomass and species composition. Warming caused a 260% increase in total emission rate for the ecosystem and a 90% increase in emission rates for plants, while having no effect on soil emissions. Compared to the control, reduced sunlight decreased emissions by 69% for the ecosystem, 61-65% for plants and 78% for soil. The detected strong emission response is considerably higher than observed at more southern latitudes, emphasizing the high temperature sensitivity of ecosystem processes in the changing Arctic.

  15. Secondary aerosol formation from stress-induced biogenic emissions and possible climate feedbacks

    Directory of Open Access Journals (Sweden)

    Th. F. Mentel

    2013-09-01

    Full Text Available Atmospheric aerosols impact climate by scattering and absorbing solar radiation and by acting as ice and cloud condensation nuclei. Biogenic secondary organic aerosols (BSOAs comprise an important component of atmospheric aerosols. Biogenic volatile organic compounds (BVOCs emitted by vegetation are the source of BSOAs. Pathogens and insect attacks, heat waves and droughts can induce stress to plants that may impact their BVOC emissions, and hence the yield and type of formed BSOAs, and possibly their climatic effects. This raises questions of whether stress-induced changes in BSOA formation may attenuate or amplify effects of climate change. In this study we assess the potential impact of stress-induced BVOC emissions on BSOA formation for tree species typical for mixed deciduous and Boreal Eurasian forests. We studied the photochemical BSOA formation for plants infested by aphids in a laboratory setup under well-controlled conditions and applied in addition heat and drought stress. The results indicate that stress conditions substantially modify BSOA formation and yield. Stress-induced emissions of sesquiterpenes, methyl salicylate, and C17-BVOCs increase BSOA yields. Mixtures including these compounds exhibit BSOA yields between 17 and 33%, significantly higher than mixtures containing mainly monoterpenes (4–6% yield. Green leaf volatiles suppress SOA formation, presumably by scavenging OH, similar to isoprene. By classifying emission types, stressors and BSOA formation potential, we discuss possible climatic feedbacks regarding aerosol effects. We conclude that stress situations for plants due to climate change should be considered in climate–vegetation feedback mechanisms.

  16. Biogenic metallic nanoparticles as catalyst for bioelectricity production: A novel approach in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saravanakumar, Kandasamy, E-mail: saravana732@gmail.com [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China); MubarakAli, Davoodbasha [Microbial Genetic Engineering Laboratory, Division of Bioengineering, College of Life Science and Bioengineering, Incheon National University, Songdo 406772, Incheon (Korea, Republic of); Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Kathiresan, Kandasamy [Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai 608 502, Tamil Nadu (India); Thajuddin, Nooruddin [Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Alharbi, Naiyf S. [Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Chen, Jie, E-mail: jiechen59@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China)

    2016-01-15

    Highlights: • Trichoderma sp., showed an abilities to synthesis of AgNPs and AuNPs with an excellent stability. • AuNPs significantly enhanced the bioelectricity production by MFC of anaerobic fermentation as catalyst. • Maximum bioelectricity production was optimized and obtained the voltage of 432.80 mA using RSM. - Abstract: The present work aimed to use the biogenic metallic nanoparticles as catalyst for bioelectricity production in microbial fuel cell (MFC) approach under anaerobic condition. Silver and gold nanoparticles (AuNPs) were synthesized using Trichoderma sp. Particle size and cystallinity were measured by X-ray diffraction revealed the crystalline structure with average size of 36.17 nm. Electron microscopic studies showed spherical shaped silver nanoparticles (AgNPs) and cubical shaped AuNPs with size ranges from 50 to 150 nm. The concentration of biogenic metallic nanoparticles as catalyst for enhanced bioelectricity generations and estimated by response surface methodology (RSM) and found at the greatest of 342.80 mA under optimized conditions are time interval, temperature, nanoparticles used as 63 h, 28 ± 2.0 °C, 22.54 mg l{sup −1} (AgNPs) and 25.62 mg l{sup −1} (AuNPs) in a batch reactor. AuNPs acted as an excellent catalyst to enhance the bioelectricity production. This novel technique could be used for eco-friendly, economically feasible and facile electricity production.

  17. Conjugation of biogenic and synthetic polyamines with serum proteins: A comprehensive review.

    Science.gov (United States)

    Chanphai, P; Thomas, T J; Tajmir-Riahi, H A

    2016-11-01

    We have reviewed the conjugation of biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) with human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. The results of multiple spectroscopic methods and molecular modeling were analysed here and correlations between polyamine binding mode and protein structural changes were estabilished. Polyamine-protein bindings are mainly via hydrophilic and H-bonding contacts. BSA forms more stable conjugates than HSA and b-LG. Biogenic polyamines form more stable complexes than synthetic polyamines except in the case of b-LG, where the protein shows more hydrophobic character than HSA and BSA. The loading efficacies were 40-52%. Modeling showed the presence of several H-bonding systems, which stabilized polyamine-protein conjugates. Polyamine conjugation induced major alterations of serum protein conformations. The potential application of serum proteins in delivery of polyamines is evaluated here.

  18. Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles.

    Science.gov (United States)

    Składanowski, M; Golinska, P; Rudnicka, K; Dahm, H; Rai, M

    2016-12-01

    The study was focused on assessment of antibacterial activity, cytotoxicity and immune compatibility of biogenic silver nanoparticles (AgNPs) synthesized from Streptomyces sp. NH28 strain. Nanoparticles were biosynthesized and characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nanoparticle tracking analysis system and zeta potential. Antibacterial activity was tested against Gram-positive and Gram-negative bacteria; minimal inhibitory concentration was recorded. Cytotoxicity was estimated using L929 mouse fibroblasts via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Biocompatibility of AgNPs was performed using THP1-XBlue™ cells. Biogenic AgNPs presented high antibacterial activity against all tested bacteria. Minimum inhibitory concentration of AgNPs against bacterial cells was found to be in range of 1.25-10 μg/mL. Silver nanoparticles did not show any harmful interaction to mouse fibroblast cell line, and no activation of nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cells was observed at concentration below 10 µg/mL. The half-maximal inhibitory concentration (IC50) value was established at 64.5 μg/mL. Biological synthesis of silver can be used as an effective system for formation of metal nanoparticles. Biosynthesized AgNPs can be used as an antibacterial agent, which can be safe for eukaryotic cells.

  19. Skeletonema cf. costatum biogenic silica production rate determinated by PDMPO method

    Science.gov (United States)

    Zhang, Guicheng; Leng, Xiaoyun; Feng, Yuanyuan; Li, Xia; Sun, Jun

    2017-04-01

    Diatoms are the only ecological phytoplankton that require silicic acid for growth. They are also the dominant contributor of ocean's total primary productivity. Generation and circulation with silica walls, which the siliceous organisms form, is an important component of the marine biological pump. It is crucial to the study of the operational mechanisms of biological pump with different sea areas. Moreover, it is the key link to the study of global silicon cycle. This paper introduces the basic mechanism of the formation of diatom silica walls and a new way of researching silicic acid metabolism, namely the 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)- methoxy)phenyl)oxazole (PDMPO) dyeing method. Under a fluorescence microscope after excitation with bright green fluorescence, it can combine with silicic acid to form a complex into the Si deposition within diatom cells. The advantage of this method is that it can monitor the metabolism of silicate after adding PDMPO. For experimentation and sample collection in each of the specified time points, samples were determinated through the unutilized silicic acid, silica dissoluble intracellular and Si deposition within diatom cells, not only using hot alkaline digestions method but also PDMPO dyeing method. Results showed a good linear relationship between PDMPO fluorescent value and biogenic silica concentration. It was also indicated that PDMPO had no deleterious impact on Skeletonema cf. costatum growth for 34 h and was useful for tracking newly-deposited biogenic silica in diatoms' frustules.

  20. Milankovitch-scale correlations between deeply buried microbial populations and biogenic ooze lithology

    Science.gov (United States)

    Aiello, I.W.; Bekins, B.A.

    2010-01-01

    The recent discoveries of large, active populations of microbes in the subseafloor of the world's oceans supports the impact of the deep biosphere biota on global biogeochemical cycles and raises important questions concerning the functioning of these extreme environments for life. These investigations demonstrated that subseafloor microbes are unevenly distributed and that cell abundances and metabolic activities are often independent from sediment depths, with increased prokaryotic activity at geochemical and/or sedimentary interfaces. In this study we demonstrate that microbial populations vary at the scale of individual beds in the biogenic oozes of a drill site in the eastern equatorial Pacific (Ocean Drilling Program Leg 201, Site 1226). We relate bedding-scale changes in biogenic ooze sediment composition to organic carbon (OC) and microbial cell concentrations using high-resolution color reflectance data as proxy for lithology. Our analyses demonstrate that microbial concentrations are an order of magnitude higher in the more organic-rich diatom oozes than in the nannofossil oozes. The variations mimic small-scale variations in diatom abundance and OC, indicating that the modern distribution of microbial biomass is ultimately controlled by Milankovitch-frequency variations in past oceanographic conditions. ?? 2010 Geological Society of America.

  1. Forensic source differentiation of petrogenic, pyrogenic, and biogenic hydrocarbons in Canadian oil sands environmental samples.

    Science.gov (United States)

    Wang, Zhendi; Yang, C; Parrott, J L; Frank, R A; Yang, Z; Brown, C E; Hollebone, B P; Landriault, M; Fieldhouse, B; Liu, Y; Zhang, G; Hewitt, L M

    2014-04-30

    To facilitate monitoring efforts, a forensic chemical fingerprinting methodology has been applied to characterize and differentiate pyrogenic (combustion derived) and biogenic (organism derived) hydrocarbons from petrogenic (petroleum derived) hydrocarbons in environmental samples from the Canadian oil sands region. Between 2009 and 2012, hundreds of oil sands environmental samples including water (snowmelt water, river water, and tailings pond water) and sediments (from river beds and tailings ponds) have been analyzed. These samples were taken from sites where assessments of wild fish health, invertebrate communities, toxicology and detailed chemistry are being conducted as part of the Canada-Alberta Joint Oil Sands Monitoring Plan (JOSMP). This study describes the distribution patterns and potential sources of PAHs from these integrated JOSMP study sites, and findings will be linked to responses in laboratory bioassays and in wild organisms collected from these same sites. It was determined that hydrocarbons in Athabasca River sediments and waters were most likely from four sources: (1) petrogenic heavy oil sands bitumen; (2) biogenic compounds; (3) petrogenic hydrocarbons of other lighter fuel oils; and (4) pyrogenic PAHs. PAHs and biomarkers detected in snowmelt water samples collected near mining operations imply that these materials are derived from oil sands particulates (from open pit mines, stacks and coke piles).

  2. Enzyme sensor array for the determination of biogenic amines in food samples

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Jana [University of Greifswald, Institute for Chemistry and Biochemistry (Germany); Wittmann, Christine [Fachhochschule Neubrandenburg, Department of Technology (Germany)

    2002-01-01

    An enzyme sensor array for the simultaneous determination of the three biogenic amines (histamine, tyramine and putrescine) by pattern recognition using an artificial neural network and its application to different food samples is described. A combination of a monoamine oxidase, a tyramine oxidase and a diamine oxidase (with specific activities sufficient for rapid detection) are immobilised each on a separate screen-printed thick-film electrode via transglutaminase and glutaraldehyde to compare these cross-linking reagents with regard to their suitability. To calculate the amount of a specific biogenic amine, the raw data from multichannel software were transferred to a neural network. The sensor array takes 20 min to complete (excluding statistical data analysis) with only one extraction and subsequent neutralisation step required prior to sensor measurement. The lower detection limits with the enzyme sensor were 10 mg/kg for histamine and tyramine, and 5 mg/kg for putrescine with a linear range up to 200 mg/kg for histamine and tyramine and 100 mg/kg for putrescine. The application area of the enzyme sensor array was tested from fish to meat products, sauerkraut, beer, dairy products, wine and further fermented foods and compared with the data of conventional LC analyses (mean correlation coefficient: 0.854). (orig.)

  3. Ultra-performance convergence chromatography (UPC²) method for the analysis of biogenic amines in fermented foods.

    Science.gov (United States)

    Gong, Xiao; Qi, Ningli; Wang, Xiaoxi; Lin, Lijing; Li, Jihua

    2014-11-01

    A rapid ultra-performance convergence chromatography (UPC(2)) method for the determination of eight biogenic amines (spermine, spermidine, putrescine, cadaverine, tryptamine, phenylethylamine, histamine and tyramine) in fermented foods was developed. The amines were pre-column derivatized with dansyl chloride and separated on UPC(2) system with a HSS C18 SB column (3.0 × 100 mm, 1.8 μm) using gradient elution with a binary system of CO2 and n-hexane:isopropanol:ammonium hydroxide (70:30:0.15, v/v/v), back pressure of 2,000 psi, flow rate of 2.0 ml/min and DAD detection at 254 nm. The result showed excellent linearity (r=0.9995-1.0000). Limits of detection (LOD) and limits of quantification (LOQ) were 21-67 ng/L and 72-224 ng/L, respectively. Relative standard deviations (RSD) for repeatability and reproducibility were 0.21-0.87% and 1.98-4.02%, respectively. Furthermore, this method was successfully applied to analysis of biogenic amines in Yulu and Sufu samples.

  4. Tropospheric methanol observations from space: constraints on the seasonality of biogenic emissions

    Science.gov (United States)

    Wells, K. C.; Millet, D. B.; Cady-Pereira, K. E.; Shephard, M. W.; Xiao, Y.; Razavi, A.; Clerbaux, C.

    2011-12-01

    Methanol is the most abundant non-methane organic compound in the atmosphere, and is an important precursor of atmospheric pollutants such as CO and formaldehyde. The recent development of methanol retrievals from nadir-viewing satellite-based platforms offers powerful new information for quantifying methanol emissions on a global scale. This study uses methanol observations from the Tropospheric Emission Spectrometer (TES) on the Aura satellite and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A satellite, in conjunction with aircraft data, to investigate methanol emissions from major plant functional types in the GEOS-Chem global chemical transport model (driven with MEGAN biogenic emissions). We first evaluate the TES methanol retrievals by comparing to simulation results and flight observations from several North American field campaigns. Results show that the retrieval performs well when the degrees of freedom for signal are above 0.5. We analyze one full year of TES and IASI observations and find a persistent model underestimate in springtime, and make recommendations for an improved seasonal distribution of biogenic methanol emissions over temperate regions of the globe.

  5. Engineering biogenic magnetite for sustained Cr(VI) remediation in flow-through systems.

    Science.gov (United States)

    Crean, Daniel E; Coker, Victoria S; van der Laan, Gerrit; Lloyd, Jonathan R

    2012-03-20

    In this work, we report a route to enhance the reactivity and longevity of biogenic magnetite in Cr(VI) remediation under continuous-flow conditions by combining functionalization of the biomagnetite surface with a precious metal catalyst, nanoscale palladium, and exposure to formate. Column influent conditions were varied to simulate oxic, anoxic, and nitrate cocontaminated environments. The addition of sodium formate as an electron donor for Pd-functionalized magnetite increased capacity and longevity allowing 80% removal of Cr(VI) after 300 h in anoxic conditions, whereas complete breakthrough occurred after 60 h in anoxic nonformate and nonfunctionalized systems. Removal of Cr(VI) was optimized under anoxic conditions, and the presence of oxidizing agents results in a modest loss in reductive capacity. Examination of reacted Pd-functionalized magnetite reveals close association of Fe with Cr, suggesting that Pd-coupled oxidation of formate serves to regenerate the reactive surface. XMCD studies revealed that Cr(III) is partially substituted for Fe in the magnetite structure, which serves to immobilize Cr. No evidence for a mechanistic interference by nitrate cocontamination was observed, suggesting that this novel system could provide robust, effective and sustained reduction of contaminants, even in the presence of common oxidizing cocontaminants, outperforming the reductive capacity of nonfunctionalized biogenic magnetite.

  6. Processing and characterization of glass reinforced biogenic hydroxyapatite composites with ferromagnetic additives

    Directory of Open Access Journals (Sweden)

    Nataliya Pinchuk

    2008-06-01

    Full Text Available Biogenic hydroxyapatite-glass composites, with addition of up to 2 wt.% of Fe or Fe3O4, were fabricated from biogenic hydroxyapatite powder and four types of reinforcing glasses by sintering under different conditions. It has been established that the relative density, mechanical and magnetic properties of the prepared composites depend on the composition and sintering conditions. The composites with 1 wt.% Fe or Fe3O4 sintered at 500°С in vacuum have a magnetic susceptibility of 2–3·10-3 cm3/g. This parameter decreases to 0.858·10-3 cm3/g for the specimens with 1 wt.% additives sintered at 800°С in vacuum and to 0.27–1.3·10-3cm3/g for the specimens with 2 wt.% additives sintered at 500°С under the usual atmospheric conditions. The magnetic susceptibility for the specimens with 2 wt.% additives sintered at 780°С under the same atmospheric conditions decreases to 0.24–1.25·10-6 cm3/g. These ferromagnetic additives influence the degradation rate in vitro within the first 40 min of the composite soaking. Short-term treatment of specimens by the magnetic field leads to an increase in the initial degradation rate, but insignificantly influences it within more prolonged soaking.

  7. Evidence for the presence of biogenic magnetic particles in the nocturnal migratory brown planthopper, Nilaparvata lugens.

    Science.gov (United States)

    Pan, Weidong; Wan, Guijun; Xu, Jingjing; Li, Xiaoming; Liu, Yuxin; Qi, Liping; Chen, Fajun

    2016-01-05

    Biogenic magnetic particles have been detected in some migratory insects, which implies the basis of magnetoreception mechanism for orientation and navigation. Here, the biogenic magnetic particles in the migratory brown planthopper (BPH), Nilaparvata lugens were qualitatively measured by SQUID magnetometry, and their characteristics were further determined by Prussian Blue staining, electron microscopy and energy dispersive x-ray spectroscopy. The results indicate that there were remarkable magnetic materials in the abdomens and not in the head or thorax of the 3(rd)-5(th) instar nymphs, and in macropterous and brachypterous female and male adults of BPH. The size of magnetic particles was shown to be between 50-450 nm with a shape factor estimate of between 0.8-1.0 for all the tested BPHs. Moreover, the amount of magnetic particles was associated with the developmental stage (the 3(rd)-5(th) instar), wing form (macropterous vs. brachypterous) and sex. The macropterous female adults had the largest amount of magnetic particles. Although the existence of magnetic particles in the abdomens of BPH provides sound basis for the assumption of magnetic orientation, further behavioral studies and complementary physical characterization experiments should be conducted to determine whether the orientation behavior of BPH is associated with the magnetic particles detected in this study.

  8. 'Nano' Morphology and Element Signatures of Early Life on Earth: A New Tool for Assessing Biogenicity

    Science.gov (United States)

    Oehler, D. Z.; Mostefaoui, S.; Meibom, A.; Selo, M.; McKay, D. S.; Robert, F.

    2006-01-01

    The relatively young technology of NanoSIMS is unlocking an exciting new level of information from organic matter in ancient sediments. We are using this technique to characterize Proterozoic organic material that is clearly biogenic as a guide for interpreting controversial organic structures in either terrestrial or extraterrestrial samples. NanoSIMS is secondary ion mass spectrometry for trace element and isotope analysis at sub-micron resolution. In 2005, Robert et al. [1] combined NanoSIMS element maps with optical microscopic imagery in an effort to develop a new method for assessing biogenicity of Precambrian structures. The ability of NanoSIMS to map simultaneously the distribution of organic elements with a 50 nm spatial resolution provides new biologic markers that could help define the timing of life s development on Earth. The current study corroborates the work of Robert et al. and builds on their study by using NanoSIMS to map C, N (as CN), S, Si and O of both excellently preserved microfossils and less well preserved, non-descript organics in Proterozoic chert from the ca. 0.8 Ga Bitter Springs Formation of Australia.

  9. Effects of biogenic nitrate chemistry on the NOx lifetime in remote continental regions

    Science.gov (United States)

    Browne, E. C.; Cohen, R. C.

    2012-12-01

    We present an analysis of the NOx budget in conditions of low NOx (NOx = NO + NO2) and high biogenic volatile organic compound (BVOC) concentrations that are characteristic of most continental boundary layers. Using a steady-state model, we show that below 500 pptv of NOx, the NOx lifetime is extremely sensitive to organic nitrate (RONO2) formation rates. We find that even for RONO2 formation values that are an order of magnitude smaller than is typical for continental conditions significant reductions in NOx lifetime, and consequently ozone production efficiency, are caused by nitrate forming reactions. Comparison of the steady-state box model to a 3-D chemical transport model (CTM) confirms that the concepts illustrated by the simpler model are a useful approximation of predictions provided by the full CTM. This implies that the regional and global budgets of NOx, OH, and ozone will be sensitive to assumptions regarding organic nitrate chemistry. Changes in the budgets of these species affect the representation of processes important to air quality and climate. Consequently, CTMs must include an accurate representation of organic nitrate chemistry in order to provide accurate assessments of past, present, and future air quality and climate. These findings suggest the need for further experimental constraints on the formation and fate of biogenic RONO2.

  10. Biogenic amine – surfactant interactions at the air-water interface.

    Science.gov (United States)

    Penfold, J; Thomas, R K; Li, P X

    2015-07-01

    The strong interaction between polyamines and anionic surfactants results in pronounced adsorption at the air-water interface and can lead to the formation of layered surface structures. The transition from monolayer adsorption to more complex surface structures depends upon solution pH, and the structure and molecular weight of the polyamine. The effects of manipulating the polyamine molecular weight and structure on the adsorption of the anionic surfactant sodium dodecyl sulphate at the air-water interface are investigated using neutron reflectivity and surface tension, for the biogenic amines putrescine, spermidine and spermine. The results show how changing the number of amine groups and the spacing between the amine groups impacts upon the surface adsorption. At lower pH, 3-7, and for the higher molecular weight polyamines, spermidine and spermine, ordered multilayer structures are observed. For putrescine at all pH and for spermidine and spermine at high pH, monolayer adsorption with enhanced surfactant adsorption compared to the pure surfactant is observed. The data for the biogenic amines, when compared with similar data for the polyamines ethylenediamine, diethylenetriamine and triethylenetetramine, indicate that the spacing between amines groups is more optimal for the formation of ordered surface multilayer structures.

  11. Biogenic hydrogen peroxide as a possible adaptation of life on Mars: the search for biosignatures

    Science.gov (United States)

    Houtkooper, J. M.; Schulze-Makuch, D.

    2007-08-01

    , 2007), it may be interesting to consider possible biosignatures in the environment, based on what might be inferred from the putative organisms. The metabolism is constrained by the necessity to produce an excess of H2O2 from the environment and the release of possible metabolites. The production of H2O2 can be realized from the available constituents in the atmosphere, CO2, H2O and O2. The last two components are present as a small fraction of the Martian atmosphere, but so is CO2 in Earth's atmosphere. Possible overall metabolic pathways are: CO2 + 3 H2O !CH2O + 2 H2O2(1) CO2 + 6 H2O !CH4 + 4 H2O2(2) CO2 + H2O !CO + H2O2(3) O2 + 2 H2O !2 H2O2(4) These pathways produce the following metabolites: (1) either organic macromolecules, which stay in or at the organisms, or, formaldehyde, released into the atmosphere; (2) methane, released into the atmosphere; (3) carbon monoxide, released into the atmosphere; and (4) only H2O2; this last pathway is energetically the least costly way to produce H2O2, despite O2 being a minor component (0.1%) of the atmosphere. As the amount of biomass in the Martian soil could be as high as 1300 ppm (Houtkooper and Schulze-Makuch, 2007), it might be possible to detect seasonal variations in the metabolic endproducts of formaldehyde, CH4, CO and O2. Even more interesting would be the observation of local variations in the surface boundary layer, in which diurnal rhythms might be revealed. Since a metabolic pathway would be involved, an additional signature could be the isotopic ratios of carbon and oxygen. Continuous monitoring of the composition, especially of the minor constituents of the atmosphere should therefore have a high priority in future missions to Mars, especially lander missions. Other signatures to be watched for are the spectral absorption of pigments providing UV shielding and photosynthesis. References: Houtkooper, J.M., and Schulze-Makuch, D. (2007) A Possible Biogenic Origin for Hydrogen Peroxide on Mars: The Viking

  12. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A

    Science.gov (United States)

    Warwick, P.D.; Breland, F.C.; Hackley, P.C.

    2008-01-01

    New coal-gas exploration and production in northern Louisiana and south-central Mississippi, Gulf of Mexico Basin, is focused on the Wilcox Group (Paleocene-Eocene), where the depth to targeted subbituminous C to high volatile C bituminous coal beds ranges from 300 to 1680??m, and individual coal beds have a maximum thickness of about 6??m. Total gas content (generally excluding residual gas) of the coal beds ranges from less than 0.37??cm3/g (as-analyzed or raw basis; 1.2??cm3/g, dry, ash free basis, daf) at depths less than 400??m, to greater than 7.3??cm3/g (as-analyzed basis; 8.76??cm3/g, daf) in deeper (> 1,500??m) parts of the basin. About 20 Wilcox coal-gas wells in northern Louisiana produce from 200 to 6485??m3 of gas/day and cumulative gas production from these wells is approximately 25??million m3 (as of December, 2006). U.S. Geological Survey assessment of undiscovered, technically recoverable gas resources in the Gulf of Mexico Coastal Plain, including northern and south-central Mississippi, indicates that coal beds of the Wilcox Group contain an estimated mean total 109.3??million m3 (3.86??trillion ft3) of producible natural gas. To determine the origin of the Wilcox Group coal gases in northern Louisiana, samples of gas, water, and oil were collected from Wilcox coal and sandstone reservoirs and from under- and overlying Late Cretaceous and Eocene carbonate and sandstone reservoirs. Isotopic data from Wilcox coal-gas samples have an average ??13CCH4 value of - 62.6??? VPDB (relative to Vienna Peedee Belemnite) and an average ??DCH4 value of - 199.9??? VSMOW (relative to Vienna Standard Mean Ocean Water). Values of ??13CCO2 range from - 25.4 to 3.42??? VPDB. Produced Wilcox saline water collected from oil, conventional gas, and coalbed gas wells have ??DH2O values that range from - 27.3 to - 18.0??? VSMOW. These data suggest that the coal gases primarily are generated in saline formation water by bacterial reduction of CO2. Shallow (hydrocarbons from

  13. Past Warmer Climate Periods at the Antarctic Margin Detected From Proxies and Measurements of Biogenic Opal in the AND-1B Core: The XRF Spectral Silver (Ag) Peak Used as a new Tool for Biogenic Opal Quantification.

    Science.gov (United States)

    Kuhn, G.; Helling, D.; von Eynatten, H.; Niessen, F.; Magens, D.

    2008-12-01

    Quantification of biogenic opal in marine sediments is a time consuming job, but the results could indicate periods of higher bioproductivity and warmer conditions than today at the Antarctic margin. Within the international Antarctic Geological Drilling Program (ANDRILL), core AND-1B was drilled and recovered a 1285 m sequence from a flexural moat basin filled with glacimarine, terrigenous, volcanic and biogenic sediments below the McMurdo Ice Shelf. Our main goal is to study the variability and the stability of the Ross Ice Shelf from Miocene to Recent. The melting and collapse of large Antarctic ice shelves may cause a significant sea level rise because of accelerated inland ice glacier surges into the ocean. Biogenic opal content in sediments can be deduced indirectly from grain density measurements on single samples, or faster and more continuous by gamma ray attenuation measurements on the core, with subsequent wet bulk and grain density calculations. Spectral colour reflectance (b* value) measurements on the split core surface can also be a fast tool for opal content quantification. Of course, they all have disadvantages in comparison to direct measurement on samples using X-ray diffraction or geochemical leaching methods. Some major and minor chemical elements were measured directly on split core surfaces with a non- destructive X-Ray Fluorescence Core Scanner method (XRF-CS, Avaatech) in the field. Quantitative geochemical analyses like determination of total inorganic and organic carbon (TOC), biogenic opal as well as major and minor elements were done on core samples. We found a strong positive correlation between the counts per second of the XRF-CS Ag peak area and the biogenic opal content of the samples (r=0.81) not only in the AND-1B core but in others as well from the Antarctic margin. In literature, it is noted that diatoms could accumulate Ag in sediments, so at first we were pleased to find this Ag enrichment with our tool. But further

  14. Early PCR detection of tyramine-producing bacteria during cheese production.

    Science.gov (United States)

    Fernández, María; Belén Flórez, Ana; Linares, Daniel M; Mayo, Baltasar; Alvarez, Miguel A

    2006-08-01

    Biogenic amines (BA) are toxic substances that appear in foods and beverages. Tyramine is the most abundant BA in cheeses. A PCR method was developed to detect the presence of tyramine-producing bacteria during cheese manufacture and ripening. Six different batches of a farmhouse blue cheese were analysed by PCR. Tyramine concentrations were also determined by HPLC. The PCR method was able to anticipate tyramine accumulation in the cheeses; the presence of tyramine-producing microorganisms in the early stages of manufacture correlated well with a high concentration of BA in mature cheese samples.

  15. Determination of the biogenic secondary organic aerosol fraction in the boreal forest by NMR spectroscopy

    Directory of Open Access Journals (Sweden)

    E. Finessi

    2012-01-01

    Full Text Available The study investigates the sources of fine organic aerosol (OA in the boreal forest, based on measurements including both filter sampling (PM1 and online methods and carried out during a one-month campaign held in Hyytiälä, Finland, in spring 2007. Two aerosol mass spectrometers (Q-AMS, ToF-AMS were employed to measure on-line concentrations of major non-refractory aerosol species, while the water extracts of the filter samples were analyzed by nuclear magnetic resonance (NMR spectroscopy for organic functional group characterization of the polar organic fraction of the aerosol. AMS and NMR spectra were processed separately by non-negative factorization algorithms, in order to apportion the main components underlying the submicrometer organic aerosol composition and depict them in terms of both mass fragmentation patterns and functional group compositions.

    The NMR results supported the AMS speciation of oxidized organic aerosol (OOA into two main fractions, which could be generally labelled as more and less oxidized organics. The more oxidized component was characterized by a mass spectrum dominated by the m/z 44 peak, and in parallel by a NMR spectrum showing aromatic and aliphatic backbones highly substituted with oxygenated functional groups (carbonyls/carboxyls and hydroxyls. Such component, contributing on average 50% of the OA mass throughout the observing period, was associated with pollution outbreaks from the Central Europe. The less oxidized component was enhanced in concomitance with air masses originating from the North-to-West sector, in agreement with previous investigations conducted at this site. NMR factor analysis was able to separate two distinct components under the less oxidized fraction of OA. One of these NMR-factors was associated with the formation of terrestrial biogenic secondary organic aerosol (BSOA, based on the comparison with spectral profiles obtained from laboratory experiments of

  16. Chemistry of new particle growth in mixed urban and biogenic emissions – insights from CARES

    Directory of Open Access Journals (Sweden)

    A. Setyan

    2014-01-01

    carbon, CO, NOx, and toluene were significantly higher whereas the photo-oxidation products of biogenic VOC and the biogenically-influenced SOA also increased moderately during the NPE days compared to the non-event days. These results indicate that the frequently occurring NPE over the Sacramento and Sierra Nevada regions were mainly driven by urban plumes from Sacramento and that the interaction of regional biogenic emissions with the urban plumes has enhanced the new particle growth. This finding has important implication for quantifying the climate impacts of NPE on global scale.

  17. Dynamics of biogenic Si in freshwater tidal marshes: Si generation and retention in marsh sediments (Scheldt estuary)

    NARCIS (Netherlands)

    Struyf, E.; Temmerman, S.; Meire, P.

    2007-01-01

    The sequestration and recycling of biogenic silica (BSi) in freshwater tidal marshes was modelled through the combination of short-term year round sediment trap data with a long-term sedimentation model, MARSED. The modelling was implemented through the complete evolution from a young rapidly rising

  18. Low-temperature magnetic properties of pelagic carbonates: Oxidation of biogenic magnetite and identification of magnetosome chains

    NARCIS (Netherlands)

    Chang, L.; Winklhofer, M.; Roberts, A.P.; Heslop, D.; Florindo, F.; Dekkers, M.J.; Krijgsman, W.; Kodama, K.; Yamamoto, Y.

    2013-01-01

    Pelagic marine carbonates provide important records of past environmental change. We carried out detailed low-temperature magnetic measurements on biogenic magnetite-bearing sediments from the Southern Ocean (Ocean Drilling Program (ODP) Holes 738B, 738C, 689D, and 690C) and on samples containing wh

  19. Use of small diameter column particles to enhance HPLC determination of histamine and other biogenic amines in seafood

    DEFF Research Database (Denmark)

    Simat, Vida; Dalgaard, Paw

    2011-01-01

    Pre-column and post-column HPLC derivatization methods were modified and evaluated for the identification and quantification of nine biogenic amines in seafood Two HPLC methods with column particles of 1 8 mu m or 3 mu m in diameter were modified and compared to classical methods using 5 mu m col...

  20. Composition and variability in the export of biogenic silica in the Changjiang River and the effect of Three Gorges Reservoir

    NARCIS (Netherlands)

    Ran, X.; Liu, S.; Liu, J.; Zang, J.; Che, H.; Ma, Y.; Wang, Y.

    2016-01-01

    Silicon (Si) plays an essential role in biogeochemical processes, but is still poorly characterized in the river system. This study addressed the biogenic silica (BSi) composition, origin and variation in the Changjiang River, and estimated the impacts of natural processes and human activities on th

  1. Study on biogenic amines formation and influencing factors in Chinese rice wine%黄酒中生物胺的形成及其影响因素

    Institute of Scientific and Technical Information of China (English)

    张凤杰; 薛洁; 王异静; 王德良; 周建弟; 谢广发

    2013-01-01

    The aim of present work was to study the produce of biogenic amines during brewing process for Chinese rice wine, and the influencing factors including raw material, Wheat Qu, seed starter, amino acid, brewing technique and ageing.Biogenic amines were quantified by a pre-column derivatization by high performance liquid chromatography ( HPLC).Putrescine and tryamine were the most prevalent amine.None of amines were detected in water.The aliphatic amines ( putrescine, cadaverine, spermine) were present in glutinous rice and wheat Qu, but the content was not over 6.01 mg/kg.Significantly different contents depended on seed starters (P <0.01) ranging from 16.43 to 87.72mg/L.There was a positive correlation between the content of biogenic amines and total acid, but significant negative correlation between this content and alcohol and the sense organ taste.The total content of biogenic amines during traditional brewing process was higher than that during mechanized brewing process, but both had same change tendency, i.e., increasing in early fermentation period and followed with decreasing, which was the same to bacterial count.Statistically significant increase was found in analyzed amino acids, but there was no correlation between it and the content of biogenic amines.Slight decreases came about during ageing for traditional rice wine, but irregular changes for mechanized rice wine.Overall, total content of biogenic amines ranging from 0.14 to 175.15 mg/L were within the safe level for human health .%采用高效液相色谱技术,分析了黄酒酿造原料、发酵剂和不同年份酒中的生物胺含量,并对传统工艺和机械化生产过程中生物胺含量的变化进行了跟踪分析,剖析了影响生物胺含量的因素.结果表明,腐胺和酪胺是黄酒中的主要生物胺,糯米原料和曲中生物胺含量很低,检出的3种脂肪族生物胺(腐胺、尸胺和精胺)总量不超过6.0lmg/kg;7种酒母中生物胺总含量差异极显著(P<0

  2. A new method to determine the ratio of electricity production from fossil and biogenic sources in waste-to-Energy plants.

    Science.gov (United States)

    Fellner, Johann; Cencic, Oliver; Rechberger, Helmut

    2007-04-01

    New directives of the European Union require operators of waste-to-energy (WTE) plants to report the amount of electricity that is produced from renewable sources in the waste feed. Until now, the standard method to determine the portion of renewable electricity is sorting the wastes into defined fractions of fossil organic and biogenic waste components and determining the lower heating value of these fractions. Out of it the amount of electricity production from renewables is calculated. This practice is labor and cost intensive. Therefore, it is usually carried out once a year which provides only a snapshot analysis of limited significance. This paper proposes a method to calculate the portion of electricity produced from renewable materials in waste continuously by solving a set of equations. All data required are either available from literature or from operating data routinely measured in WTE plants. The advantages are statistically derived uncertainty of the result, temporal resolution of the result down to daily mean values, low implementation efforts, and virtually no operational costs. An example of the implementation of the method to a 60 000 tons per year WTE plant is given.

  3. Biogenic Aerosols—Effects on Clouds and Climate (BAECC) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Petäjä, T [Atmospheric Radiation Measurement, Washington, DC (United States); Moisseev, D [Univ. of Helsinki (Finland); Atmospheric Radiation Measurement, Washington, DC (United States); Sinclair, V [Atmospheric Radiation Measurement, Washington, DC (United States); O’Connor, E [Atmospheric Radiation Measurement, Washington, DC (United States); Manninen, A [Univ. of Helsinki (Finland); Atmospheric Radiation Measurement, Washington, DC (United States); Levula, J [Univ. of Helsinki (Finland); Atmospheric Radiation Measurement, Washington, DC (United States); Väänänen, R [Atmospheric Radiation Measurement, Washington, DC (United States); Heikkinen, L [Atmospheric Radiation Measurement, Washington, DC (United States); Äijälä, M [Atmospheric Radiation Measurement, Washington, DC (United States); Aalto, J [Atmospheric Radiation Measurement, Washington, DC (United States); Thornton, JA [Atmospheric Radiation Measurement, Washington, DC (United States)

    2016-03-01

    Atmospheric aerosol particles impact human health in urban environments, while on regional and global scales they can affect climate patterns, the hydrological cycle, and the intensity of radiation that reaches the Earth’s surface. In spite of recent advances in the understanding of aerosol formation processes and the links between aerosol dynamics and biosphere-atmosphere-climate interactions, great challenges remain in the analysis of related processes on a global scale. Boreal forests, situated in a circumpolar belt in the Northern latitudes throughout the United States, Canada, Russia, and Scandinavia, are, of all biomes, among the most active areas of atmospheric aerosol formation. The formation of aerosol particles and their growth to cloud condensation nuclei sizes in these areas are associated with biogenic volatile organic emissions (BVOC) from vegetation and soil.

  4. Metabolites of Microbial Origin with an Impact on Health: Ochratoxin A and Biogenic Amines

    Science.gov (United States)

    Russo, Pasquale; Capozzi, Vittorio; Spano, Giuseppe; Corbo, Maria R.; Sinigaglia, Milena; Bevilacqua, Antonio

    2016-01-01

    Safety and quality are significant challenges for food; namely, safety represents a big threat all over the world and is one of the most important goal to be achieved in both Western Society and Developing Countries. Wine safety mainly relies upon some metabolites and many of them are of microbial origin. The main goal of this review is a focus on two kinds of compounds (biogenic amines and mycotoxins, mainly Ochratoxin A) for their deleterious effects on health. For each class of compounds, we will focus on two different traits: (a) synthesis of the compounds in wine, with a brief description of the most important microorganisms and factors leading this phenomenon; (b) prevention and/or correction strategies and new trends. In addition, there is a focus on a recent predictive tool able to predict toxin contamination of grape, in order to perform some prevention approaches and achieve safe wine. PMID:27092133

  5. Increased biogenic catecholamine and metabolite levels in two patients with malignant catatonia

    Directory of Open Access Journals (Sweden)

    Nisijima K

    2013-08-01

    Full Text Available Koichi Nisijima Department of Psychiatry, Jichi Medical University, Tochigi, Japan Abstract: The pathophysiology of malignant catatonia, a rare life-threatening psychiatric syndrome, has not yet been elucidated. This paper reports on two patients with malignant catatonia who showed elevated urinary or plasma catecholamine levels. Patient 1 had high catecholamine and metabolite levels in a 24-hour urine sample, and patient 2 had elevated plasma catecholamine levels. These findings indicate the presence of peripheral sympathetic nervous system hyperactivity in malignant catatonia. Symptoms of autonomic dysfunction, including tachycardia, labile blood pressure, and diaphoresis, are typical features of malignant catatonia and may be related to the increased levels of biogenic amines in these cases. Although the findings in the present study cannot entirely explain the pathophysiology of malignant catatonia, they do indicate that hyperactivity of the sympathetic nervous system may be involved in the pathology of this condition. Keywords: malignant catatonia, catecholamine levels, neuroleptic malignant syndrome

  6. Off-season biogenic volatile organic compound emissions from heath mesocosms

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Gierth, Diana; Bilde, Merete;

    2013-01-01

    measured in growth chambers by an enclosure method using gas chromatography-mass spectrometry. CO2 exchange, soil microbial biomass and soil carbon and nitrogen concentrations were also analyzed. Vegetation cutting increased BVOC emissions by more than 20-fold, and the induced compounds were mainly eight-carbon......Biogenic volatile organic compounds (BVOCs) affect both atmospheric processes and ecological interactions. Our primary aim was to differentiate between BVOC emissions from above- and belowground plant parts and heath soil outside the growing season. The second aim was to assess emissions from...... compounds and sesquiterpenes. In the Deschampsia heath, the overall low BVOC emissions originated mainly from soil. In the mixed heath, root and soil emissions were negligible. Net BVOC emissions from roots and soil of these well-drained heaths do not significantly contribute to ecosystem emissions...

  7. Secondary Organic Aerosol from biogenic VOCs over West Africa during AMMA

    Directory of Open Access Journals (Sweden)

    G. Capes

    2009-01-01

    Full Text Available This paper presents measurements of organic aerosols above subtropical West Africa during the wet season using data from the UK Facility for Airborne Atmospheric Measurements (FAAM aircraft. Measurements of biogenic volatile organic compounds (BVOC at low altitudes over these subtropical forests were made during the African Monsoon Multidisciplinary Analysis (AMMA field experiment during July and August 2006 mainly above Benin, Nigeria and Niger. Data from an Aerodyne Quadrupole Aerosol Mass Spectrometer show a median organic aerosol loading of 1.08 μg m−3 over tropical West Africa, which represents the first regionally averaged assessment of organic aerosol mass (OM in this region during the wet season. This is in good agreement with predictions based on aerosol yields from isoprene and monoterpenes during chamber studies and model predictions based on partitioning schemes, contrasting markedly with the large under representations of OM in similar models when compared with data from mid latitudes.

  8. Comparative analysis of the in vitro cytotoxicity of the dietary biogenic amines tyramine and histamine.

    Science.gov (United States)

    Linares, Daniel M; del Rio, Beatriz; Redruello, Begoña; Ladero, Victor; Martin, M Cruz; Fernandez, Maria; Ruas-Madiedo, Patricia; Alvarez, Miguel A

    2016-04-15

    Tyramine and histamine, the most toxic biogenic amines (BA), are often found in high concentrations in certain foods. Prompted by the limited knowledge of BA toxicity, and increasing awareness of the risks associated with high intakes of dietary BA, the in vitro cytotoxicity of tyramine and histamine was investigated. Tyramine and histamine were toxic for HT29 intestinal cell cultures at concentrations commonly found in BA-rich food, as determined by real-time cell analysis. Surprisingly, tyramine had a stronger and more rapid cytotoxic effect than histamine. Their mode of action was also different, while tyramine caused cell necrosis, histamine induced apoptosis. To avoid health risks, the BA content of foods should be reduced and legal limits established for tyramine.

  9. The dietary biogenic amines tyramine and histamine show synergistic toxicity towards intestinal cells in culture.

    Science.gov (United States)

    Del Rio, Beatriz; Redruello, Begoña; Linares, Daniel M; Ladero, Victor; Fernandez, Maria; Martin, Maria Cruz; Ruas-Madiedo, Patricia; Alvarez, Miguel A

    2017-03-01

    Tyramine and histamine are the biogenic amines (BA) most commonly found at high concentrations in food; they may even appear together at toxic concentrations. The present work examines, via real-time cell analysis, whether histamine and tyramine show synergistic toxicity towards intestinal cell cultures. Employing a constant equipotency ratio, their interaction was examined via the combination index (CI) method of Chou & Talalay. Co-treatment with tyramine and histamine was associated with a stronger cytotoxic effect than was treatment with either BA or on its own. Indeed, a synergistic interaction (CIhistamine, at concentrations below the legal limit, increases the cytotoxicity of tyramine at concentrations frequently reached in some foods. The synergistic cytotoxicity of tyramine and histamine should be taken into account when establishing legal limits designed to ensure consumer safety.

  10. Biogenic Fabrication of Iron/Iron Oxide Nanoparticles and Their Application

    Science.gov (United States)

    Siddiqi, Khwaja Salahuddin; ur Rahman, Aziz; Tajuddin; Husen, Azamal

    2016-11-01

    Enshrined in this review are the biogenic fabrication and applications of coated and uncoated iron and iron oxide nanoparticles. Depending on their magnetic properties, they have been used in the treatment of cancer, drug delivery system, MRI, and catalysis and removal of pesticides from potable water. The polymer-coated iron and iron oxide nanoparticles are made biocompatible, and their slow release makes them more effective and lasting. Their cytotoxicity against microbes under aerobic/anaerobic conditions has also been discussed. The magnetic moment of superparamagnetic iron oxide nanoparticles changes with their interaction with biomolecules as a consequence of which their size decreases. Their biological efficacy has been found to be dependent on the shape, size, and concentration of these nanoparticles.

  11. Development of biogenic amines during the ripening of Italian dry sausages.

    Science.gov (United States)

    Anastasio, Aniello; Draisci, Rosa; Pepe, Tiziana; Mercogliano, Raffaelina; Quadri, Fernanda Delli; Luppi, Giovanni; Cortesi, Maria Luisa

    2010-01-01

    The effect of modification of different chemical and microbiological parameters and the production of biogenic amines (histamine, cadaverine, putrescine, and tyramine) was examined during ripening of various types of typical Italian dry sausages (salami). Water activity decreased from 0.97 to 0.87, and pH reached the lowest value between the 13th and the 20th day of the ripening period, and then increased. Putrescine (up to 122.7 mg/kg) and tyramine (up to 105.9 mg/kg) mean levels showed dominance in comparison with cadaverine (up to 26.1 mg/kg) and histamine (up to 6.2 mg/kg) mean values in all sausage types. The highest putrescine and tyramine concentrations were observed in salami with the largest diameters. This comparative study suggests a good correlation between microbial behavior and amine evolution, particularly tyramine and putrescine, in dry sausage production.

  12. Deposition of Biogenic Iron Minerals in a Methane Oxidizing Microbial Mat

    Directory of Open Access Journals (Sweden)

    Christoph Wrede

    2013-01-01

    Full Text Available The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  13. Global climate impacts of bioenergy from forests: implications from biogenic CO2 fluxes and surface albedo

    Science.gov (United States)

    Cherubini, Francesco; Bright, Ryan; Strømman, Anders

    2013-04-01

    Production of biomass for bioenergy can alter biogeochemical and biogeophysical mechanisms, thus affecting local and global climate. Recent scientific developments mainly embraced impacts from land use changes resulting from area-expanded biomass production, with several extensive insights available. Comparably less attention, however, is given to the assessment of direct land surface-atmosphere climate impacts of bioenergy systems under rotation such as in plantations and forested ecosystems, whereby land use disturbances are only temporary. In this work, we assess bioenergy systems representative of various biomass species (spruce, pine, aspen, etc.) and climatic regions (US, Canada, Norway, etc.), for both stationary and vehicle applications. In addition to conventional greenhouse gas (GHG) emissions through life cycle activities (harvest, transport, processing, etc.), we evaluate the contributions to global warming of temporary effects resulting from the perturbation in atmospheric carbon dioxide (CO2) concentration caused by the timing of biogenic CO2 fluxes and in surface reflectivity (albedo). Biogenic CO2 fluxes on site after harvest are directly measured through Net Ecosystem Productivity (NEP) chronosequences from flux towers established at the interface between the forest canopy and the atmosphere and are inclusive of all CO2 exchanges occurring in the forest (e.g., sequestration of CO2 in growing trees, emissions from soil respiration and decomposition of dead organic materials). These primary data based on empirical measurements provide an accurate representation of the forest carbon sink behavior over time, and they are used in the elaboration of high-resolution IRFs for biogenic CO2 emissions. Chronosequence of albedo values from clear-cut to pre-harvest levels are gathered from satellite data (MODIS black-sky shortwave broadband, Collection 5, MCD43A). Following the cause-effect chain from emissions to damages, through radiative forcing and changes

  14. Biogenic amines formation in high-pressure processed pike flesh (Esox lucius) during storage.

    Science.gov (United States)

    Křížek, Martin; Matějková, Kateřina; Vácha, František; Dadáková, Eva

    2014-05-15

    The effects of vacuum packaging followed by high pressure processing on the shelf-life of fillets of pike (Esox lucius) were examined. Samples were pressure-treated at 300 and 500 MPa and stored at 3.5 and 12 °C for up to 70 days. The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined. Putrescine showed very good correspondence with the level of applied pressure and organoleptic properties. Polyamines spermidine and spermine did not show statistically significant changes with the level of applied pressure and the time of storage. Increased cadaverine and tyramine contents were found in samples with good sensory signs, stored for longer time and/or kept at 12 °C, thus indicating the loss of freshness. Tryptamine and phenylethylamine were not detected in pressure-treated samples kept at 3.5 °C. Histamine was not detected in samples of good quality.

  15. Science Plan Biogenic Aerosols – Effects on Clouds and Climate (BAECC)

    Energy Technology Data Exchange (ETDEWEB)

    Petäjä, T

    2013-12-01

    Atmospheric aerosol particles impact human health in urban environments, while on regional and global scales they can affect climate patterns, the hydrological cycle, and the intensity of radiation that reaches the Earth’s surface. In spite of recent advances in the understanding of aerosol formation processes and the links between aerosol dynamics and biosphere-atmosphere-climate interactions, great challenges remain in the analysis of related processes on a global scale. Boreal forests, situated in a circumpolar belt in the northern latitudes throughout the United States, Canada, Russia and Scandinavia, are among the most active areas of atmospheric aerosol formation among all biomes. The formation of aerosol particles and their growth to the sizes of cloud condensation nuclei in these areas are associated with biogenic volatile organic emissions from vegetation and soil.

  16. Deposition of biogenic iron minerals in a methane oxidizing microbial mat.

    Science.gov (United States)

    Wrede, Christoph; Kokoschka, Sebastian; Dreier, Anne; Heller, Christina; Reitner, Joachim; Hoppert, Michael

    2013-01-01

    The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  17. Recovery of memory following forgetting induced by depletion of biogenic amines.

    Science.gov (United States)

    Quartermain, D; Judge, M E

    1983-02-01

    Following depletion of biogenic amines by reserpine, mice were trained to avoid one compartment of a shuttle box by employing the procedures of Pavlovian fear conditioning. Retention was tested one week later using both an active and a passive measure. A robust amnesia was apparent in reserpine-treated animals on both retention measures. Treatment with the mixed dopamine-serotonin agonist lisuride 30 min prior to the test alleviated the memory loss. Since improved retention in the drug treated mice was indexed by increased response latencies in the passive test and decreased latencies in the active test it is unlikely that the improvement in performance was the result of non-specific effects on activity. The results are consistent with the hypothesis that lisuride treatment before testing facilitates retrieval processes.

  18. Modulation by Biogenic Amines for the Hemocyte Count and Prophenoloxidase Exocytosis via Receptors in Litopenaeus vannamei

    Institute of Scientific and Technical Information of China (English)

    PAN Luqing; LIU Huijie; YU Jinhong

    2011-01-01

    Hemocyte counts and phenoloxidase (PO) activity were examined after hemolymph being incubated in dopamine (DA),noradrenaline (NE) and serotonin (5-HT).Results showed that all the three biogenic amines (BAs) had a significant impact on total hemocyte count (THC),differential hemocyte count (DHC),and intracelluar and extracelluar phenoloxidase (PO) activity.Among these Bas,DA had the strongest effect on the above parameters,whereas 5-HT had the least effect.Preincubation with D1 receptor antagonist SCH23390,D2 receptor antagonist Sulpiride and 1∶1 admixture of the two could significantly inhibit the effect of DA on these parameters.SCH23390 showed a stronger inhibitory effect than Sulpiride,and the admixture exhibited the strongest effect.These results suggested that the change of hemocyte count and activation of prophenoloxidase (proPO) system in Litopenaeusvannamei hemocyte can be regulated by BAs,and DA modulates the two parameters via its receptors.

  19. Evidence of Aqueous Secondary Organic Aerosol Formation from Biogenic Emissions in the North American Sonoran Desert

    Science.gov (United States)

    Sorooshian, A.; Youn, J.; Wang, Z.; Wonaschuetz, A.; Arellano, A. F.; Betterton, E. A.

    2013-12-01

    This study examines the role of aqueous secondary organic aerosol (SOA) formation in the North American Sonoran Desert as a result of intense solar radiation, enhanced moisture, and biogenic volatile organic compounds (BVOCs). The ratio of water-soluble organic carbon (WSOC) to organic carbon (OC) nearly doubles during the monsoon season relative to other seasons of the year. When normalized by mixing height, the WSOC enhancement during monsoon months relative to preceding dry months (May - June) exceeds that of sulfate by nearly a factor of ten. WSOC:OC and WSOC are most strongly correlated with moisture parameters, temperature, and concentrations of ozone and BVOCs. No positive relationship was identified between WSOC or WSOC:OC and anthropogenic tracers such as carbon monoxide over a full year. These results are especially of significance as recent modeling studies suggest that aqueous SOA formation is geographically concentrated in the eastern United States and likely unimportant in other areas such as the Southwest.

  20. Concentrations of biogenic amines in fish, squid and octopus and their changes during storage.

    Science.gov (United States)

    Hu, Yue; Huang, Zhiyong; Li, Jian; Yang, Hong

    2012-12-15

    The concentrations of seven biogenic amines (BA) were simultaneously determined in 74 samples of fish, squid and octopus, by the method of HPLC coupled with pre-column derivatisation. The relationship between the formation of BA in aquatic products and the growth of microbial flora during storage was also investigated. Results showed that putrescine, cadaverine, histamine and tyramine were the dominant BA in the studied samples, but the concentrations of histamine and tyramine were mostly less than 50 and 100 mgkg(-1), respectively. Freezing can effectively prevent the formation of BA, but the levels of putrescine, cadaverine, histamine and tyramine significantly increased (poctopus strongly and positively correlated with the formation of amines (such as putrescine, cadaverine, histamine and tyramine) during storage, except for histamine in octopus.

  1. Arctic Vegetation under Climate Change – Biogenic Volatile Organic Compound Emissions and Leaf Anatomy

    DEFF Research Database (Denmark)

    Schollert, Michelle

    Biogenic volatile organic compounds (BVOCs) emitted from terrestrial vegetation are highly reactive non-methane hydrocarbons which participate in oxidative reactions in the atmosphere prolonging the lifetime of methane and contribute to the formation of secondary organic aerosols. The BVOC...... measurements in this thesis were performed using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analyzed by gas chromatography-mass spectrometry following thermal desorption. Also modifications in leaf anatomy in response to the studied effects of climate change were assessed...... by the use of light microscopy and scanning electron microscopy. This thesis reports the first estimates of high arctic BVOC emissions, which suggest that arctic environments can be a considerable source of BVOCs to the atmosphere. The BVOC emissions differed qualitatively and quantitatively for the studied...

  2. Continuous Underway Seawater Measurements of Biogenic Volatile Organic Compounds in the Western Atlantic Ocean

    Science.gov (United States)

    Zoerb, M.; Kim, M.; Bertram, T. H.

    2014-12-01

    The products of isoprene and terpene oxidation have been shown to contribute significantly to secondary aerosol production rates over continental regions, where the emission rates have been well characterized. Significantly less is known about the emission of isoprene and monoterpenes from marine sources. We discuss the development of a chemical ionization mass spectrometer (CIMS) employing benzene reagent ion chemistry for the selective detection of biogenic volatile organic compounds. The CIMS was coupled to a seawater equilibrator for the measurement of dissolved gases in surface seawater. This system was deployed aboard the R/V Knorr during the Western Atlantic Climate Study II in Spring 2014. Here, we report surface seawater (5 m depth) concentrations of dimethyl sulfide, isoprene, and alpha-pinene. The concentration measurements are discussed in terms of surface seawater temperature, nutrient availability, and primary productivity.

  3. Novel biogenic aggregation of moss gemmae on a disappearing African glacier.

    Directory of Open Access Journals (Sweden)

    Jun Uetake

    Full Text Available Tropical regions are not well represented in glacier biology, yet many tropical glaciers are under threat of disappearance due to climate change. Here we report a novel biogenic aggregation at the terminus of a glacier in the Rwenzori Mountains, Uganda. The material was formed by uniseriate protonemal moss gemmae and protonema. Molecular analysis of five genetic markers determined the taxon as Ceratodon purpureus, a cosmopolitan species that is widespread in tropical to polar region. Given optimal growing temperatures of isolate is 20-30 °C, the cold glacier surface might seem unsuitable for this species. However, the cluster of protonema growth reached approximately 10 °C in daytime, suggesting that diurnal increase in temperature may contribute to the moss's ability to inhabit the glacier surface. The aggregation is also a habitat for microorganisms, and the disappearance of this glacier will lead to the loss of this unique ecosystem.

  4. Biogenic silver nanoparticles based on trichoderma harzianum: synthesis, characterization, toxicity evaluation and biological activity

    Science.gov (United States)

    Guilger, Mariana; Pasquoto-Stigliani, Tatiane; Bilesky-Jose, Natália; Grillo, Renato; Abhilash, P. C.; Fraceto, Leonardo Fernandes; Lima, Renata De

    2017-03-01

    White mold is an agricultural disease caused by the fungus Sclerotinia sclerotiorum, which affects important crops. There are different ways of controlling this organism, but none provides inhibition of its resistance structures (sclerotia). Nanotechnology offers promising applications in agricultural area. Here, silver nanoparticles were biogenically synthesized using the fungus Trichoderma harzianum and characterized. Cytotoxicity and genotoxicity were evaluated, and the nanoparticles were initially tested against white mold sclerotia. Their effects on soybean were also investigated with no effects observed. The nanoparticles showed potential against S. sclerotiorum, inhibiting sclerotia germination and mycelial growth. Nanoparticle characterization data indicated spherical morphology, satisfactory polydispersity and size distribution. Cytotoxicity and genotoxicity assays showed that the nanoparticles caused both the effects, although, the most toxic concentrations were above those applied for white mold control. Given the potential of the nanoparticles against S. sclerotiorum, we conclude that this study presents a first step for a new alternative in white mold control.

  5. Measurement of biogenic sulfur gases emission from some Chinese and Japanese soils

    Science.gov (United States)

    Yang, Z.; Kanda, K.; Tsuruta, H.; Minami, K.

    Emission of volatile sulfur gases from waterlogged paddy soils and upland soils of China and Japan was studied in the laboratory. Emission of hydrogen sulfide (H 2S), carbonyl sulfide (COS), methyl mercaptan (CH 3SH), dimethyl sulfide (DMS), carbon disulfide (CS 2) and dimethyl disulfide (DMDS) were detected. Emission of sulfur gases from paddy soil was more than that from upland, and emission from the Chinese paddy soils was more than that from Japanese. At the same soil, emission of sulfur gases, when both organic manure and chemical fertilizer were applied was higher than when only organic manure or only chemical fertilizer was applied. Under anaerobic conditions, detected biogenic sulfur gases were far more than that under aerobic conditions, H 2S was the most obvious. The results have also shown that, at higher temperature, emission and expiration rate of volatile sulfur gases were higher than that at lower temperature.

  6. Sensitivity of biogenic volatile organic compounds to land surface parameterizations and vegetation distributions in California

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chun; Huang, Maoyi; Fast, Jerome D.; Berg, Larry K.; Qian, Yun; Guenther , A.; Gu, Dasa; Shrivastava, ManishKumar B.; Liu, Ying; Walters, Stacy; Pfister, G.; Jin, Jiming; Shilling, John E.; Warneke, Carsten

    2016-05-27

    Current climate models still have large uncertainties 24 in estimating biogenic trace gases, which can significantly affect atmospheric chemistry and secondary aerosol formation that ultimately influences air quality and aerosol radiative forcing. These uncertainties result from many factors, including uncertainties in land-surface processes and specification of vegetation types, both of which can affect the simulated near-surface fluxes of biogenic volatile organic compounds (BVOCs). In this study, the latest version of Model of Emissions of Gases and Aerosols from Nature MEGAN (MEGAN v2.1) is coupled within the land surface parameterization CLM4 in the Weather Research and Forecasting model with chemistry (WRF-Chem). In this implement, MEGAN v2.1 shares a consistent vegetation map with CLM4 for estimating BVOC emissions. This is unlike MEGAN v2.0 in the public version of WRF-Chem that uses a standalone vegetation map that differs from what is used by land surface parameterizations. This improved modeling framework is used to investigate the impact of two land surface parameterizations, CLM4 and Noah, on BVOCs and examine the sensitivity of BVOCs to vegetation distributions in California. The measurements collected during the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the California Nexus of Air Quality and Climate Experiment (CalNex) conducted during June of 2010 provide an opportunity to evaluate the simulated BVOCs. Sensitivity experiments show that land surface parameterizations do influence the simulated BVOCs, but that impact is much smaller than that of vegetation distributions. This study indicates that more effort is needed to obtain the most appropriate and accurate land cover datasets for climate and air quality models in terms of simulating BVOCs, oxidant chemistry, and consequently secondary organic aerosol formation.

  7. Seasonal cycles of biogenic volatile organic compound fluxes and concentrations in a California citrus orchard

    Science.gov (United States)

    Fares, S.; Park, J.-H.; Gentner, D. R.; Weber, R.; Ormeño, E.; Karlik, J.; Goldstein, A. H.

    2012-10-01

    Orange trees are widely cultivated in Mediterranean climatic regions where they are an important agricultural crop. Citrus have been characterized as emitters of volatile organic compounds (VOC) in chamber studies under controlled environmental conditions, but an extensive characterization at field scale has never been performed using modern measurement methods, and is particularly needed considering the complex interactions between the orchards and the polluted atmosphere in which Citrus is often cultivated. For one year, in a Valencia orange orchard in Exeter, California, we measured fluxes using PTRMS (Proton Transfer Reaction Mass Spectrometer) and eddy covariance for the most abundant VOC typically emitted from citrus vegetation: methanol, acetone, and isoprenoids. Concentration gradients of additional oxygenated and aromatic compounds from the ground level to above the canopy were also measured. In order to characterize concentrations of speciated biogenic VOC (BVOC) in leaves, we analyzed leaf content by GC-MS (Gas Chromatography - Mass Spectrometery) regularly throughout the year. We also characterized in more detail concentrations of speciated BVOC in the air above the orchard by in-situ GC-MS during a few weeks in spring flowering and summer periods. Here we report concentrations and fluxes of the main VOC species emitted by the orchard, discuss how fluxes measured in the field relate to previous studies made with plant enclosures, and describe how VOC content in leaves and emissions change during the year in response to phenological and environmental parameters. The orchard was a source of monoterpenes and oxygenated VOC. The highest emissions were observed during the springtime flowering period, with mid-day fluxes above 2 nmol m-2 s-1 for methanol and up to 1 nmol m-2 s-1 for acetone and monoterpenes. During hot summer days emissions were not as high as we expected considering the known dependence of biogenic emissions on temperature. We provide

  8. The Influence of Pyrogenic, Biogenic and Anthropogenic Emissions on Ozone Production Downwind from Boreal Forest Fires

    Science.gov (United States)

    Finch, Douglas; Palmer, Paul

    2016-04-01

    Boreal forest fires emit pollutants that can have a strong influence on downwind surface ozone concentrations, with potential implications for exceeding air quality regulations. The influence of the mixing of pyrogenic, biogenic and anthropogenic emissions on ozone is not well understood. Using the nested 0.5° latitude x 0.667° longitude GEOS-Chem chemical transport model we track biomass burning plumes in North America. We identify the changes in key chemical reactions within these plumes as well as the sensitivity of ozone to the different emission sources. We illustrate the importance of this method using a case study of a multi-day forest fire during the BORTAS aircraft campaign over eastern Canada during summer 2011. We focus on emissions from the fire on the 17th of July and follow the plume for eight days. After the initial 24 hours of pyrogenic emissions the main source of VOCs is biogenic with increasing emissions from anthropogenic sources including outflow from Quebec City and Newfoundland. Using a Lagrangian framework, we show that the ozone production efficiency (OPE) of this plume decreases steadily as it moves away from the fire but increases rapidly as the plume reaches the east coast of Canada. Using a Eulerian framework we show that ozone mixing ratios of a east coast receptor region increase by approximately 15% even though the ozone tendency of the regional air mass is negative, which we find is due to the arrival of ozone precursors in the plume. We also consider the contribution of anthropogenic outflow over Nova Scotia that originates from the eastern seaboard of the United States to the local chemistry. Using these sensitivity model runs we generate a chemical reaction narrative for the plume trajectory that helps to understand the attribution of observed ozone variations.

  9. Anthropogenic and biogenic hydrocarbons in soils and vegetation from the South Shetland Islands (Antarctica).

    Science.gov (United States)

    Cabrerizo, Ana; Tejedo, Pablo; Dachs, Jordi; Benayas, Javier

    2016-11-01

    Two Antarctic expeditions (in 2009 and 2011) were carried out to assess the local and remote anthropogenic sources of aliphatic and aromatic hydrocarbons, as well as potential biogenic hydrocarbons. Polycyclic aromatic hydrocarbons (PAHs), n-alkanes, biomarkers such as phytane (Ph) and pristane (Pr), and the aliphatic unresolved complex mixture (UCM), were analysed in soil and vegetation samples collected at Deception, Livingston, Barrientos and Penguin Islands (South Shetland Islands, Antarctica). Overall, the patterns of n-alkanes in lichens, mosses and grass were dominated by odd-over-even carbon number alkanes. Mosses and vascular plants showed high abundances of n-C21 to n-C35, while lichens also showed high abundances of n-C17 and n-C19. The lipid content was an important factor controlling the concentrations of n-alkanes in Antarctic vegetation (r(2)=0.28-0.53, p-level<0.05). n-C12 to n-C35 n-alkanes were analysed in soils with a predominance of odd C number n-alkanes (n-C25, n-C27, n-C29, and n-C31), especially in the background soils not influenced by anthropogenic sources. The large values for the carbon predominance index (CPI) and the correlations between odd alkanes and some PAHs suggest the potential biogenic sources of these hydrocarbons in Antarctica. Unresolved complex mixture and CPI values ~1 detected at soils collected at intertidal areas and within the perimeter of Juan Carlos research station, further supported the evidence that even a small settlement (20 persons during the austral summer) can affect the loading of aliphatic and aromatic hydrocarbons in nearby soils. Nevertheless, the assessment of Pr/n-C17 and Ph/n-C18 ratios showed that hydrocarbon degradation is occurring in these soils.

  10. Determining the Biogenicity of Microfossils in the Apex Chert, Western Australia, Using Transmission Electron Microscopy

    Science.gov (United States)

    DeGregorio, B. T.; Sharp, T. G.

    2003-01-01

    For over a decade, the oldest evidence for life on this planet has been microfossils in the 3.5 Ga Apex Chert in Western Australia. Recently, the biogenicity of these carbon-rich structures has been called into question through reanalysis of the local geology and reinterpretation of the original thin sections. Although initially described as a stratiform, bedded chert of siliceous clasts, the unit is now thought to be a brecciated hydrothermal vein chert. The high temperatures of a hydrothermal environment would probably have detrimental effects to early non-hyperthermophilic life, compared to that of a shallow sea. Conversely, a hydrothermal origin would suggest that if the microfossils were valid, they might have been hyperthermophilic. Apex Chert controversy. The Apex Chert microfossils were originally described as septate filaments composed of kerogen similar in morphology to Proterozoic and modern cyanobacteria. However new thin section analysis shows that these carbonaceous structures are not simple filaments. Many of the original microfossils are branched and have variable thickness when the plane of focus is changed. Hydrothermal alteration of organic remains has also been suggested for the creation of these strange morphologies. Another point of contention lies with the nature of the carbon material in these proposed microfossils. Kerogen is structurally amorphous, but transforms into well-ordered graphite under high pressures and temperatures. Raman spectrometry of the carbonaceous material in the proposed microfossils has been interpreted both as partially graphitized kerogen and amorphous graphite. However, these results are inconclusive, since Raman spectrometry cannot adequately discriminate between kerogen and disordered graphite. There are also opposing views for the origin of the carbon in the Apex Chert. The carbon would be biogenic if the proposed microfossils are indeed the remains of former living organisms. However, an inorganic Fischer

  11. Heavy Metals and Biogenic Elements in Aquatic Systems of the Don River Delta

    Science.gov (United States)

    Tkachenko, Anna; Tkachenko, Oleg

    2014-05-01

    River deltas are located in the lower parts of the cascade landscape-geochemical systems of the river basins, so their geochemical conditions often characterize the anthropogenic impact on whole river system. The Don River runs through the one of the most agriculturally developed and densely populated area of Russia, and flows into the Azov Sea - the smallest and shallowest sea in the world. These factors determine the geochemical features of aquatic systems of the Don River mouth area and the specificity of the "river-sea" geochemical barrier zone. The paper presents results of the field studies of the geochemical structure of the Don River mouth area, which were conducted in frames of the RFBR project in 2012-2013. Major types of the deltaic water streams and bodies were studied in different hydrological seasons: spring floods, summer, autumn and winter low water periods. About 50 samples of water, suspended matter and 60 samples of bottom sediments have been collected and analyzed for heavy metals (Fe, Mn, Zn, Cu, Ni, Co, Pb, Cr, Cd etc.) and biogenic elements (nitrate, nitrite, ammonium, phosphates, silica, total nitrogen and phosphorus, dissolved oxygen and chlorophyll) content. To assess the toxicity degree and nutrient potential of water, bioassay test conducted by growing daphnia in water samples were held. The study shows that the Don River delta water is characterized by the relatively low values of dissolved heavy metal content. Significantly higher values of heavy metals were determined in the vicinity of settlements only. Metal accumulation in bottom sediments can be associated mainly with the rate of water flow. Higher values were found in sediments of small channels with weak flow velocity and prevailing processes of the suspended matter deposition. The data on the seasonal dynamics of nutrients and spatial variability of their forms have been obtained. The maximum concentration of nitrogen, phosphorus, silicon, and other biogenic elements are

  12. A stromatolite exhibiting both biogenic and abiogenic growth phases from the Eocene Green River Formation

    Science.gov (United States)

    Frantz, C. M.; Petryshyn, V. A.; Corsetti, F. A.; Bhartia, R.; Salas, E. C.; Nealson, K. H.

    2012-12-01

    The microstructure of microdigitate carbonate stromatolites from the Rife Bed of the Eocene Green River Formation (located near Rock Springs, Wyoming) alternates between calcite fans and micrite. Chemical and petrographic analysis of the stromatolites suggests the different microstructures result from significantly different growth regimes, potentially involving the biogenicity of the microfabrics. The calcite fan fabric is generally considered an abiogenic fabric. The micrite fabric, on the other hand, contains grains trapped at angles well beyond the angle of repose, suggesting the presence of a sticky substance (hypothesized to be microbial mats) during formation. Magnetic susceptibility has been recently developed by Petryshyn et al as a biosignature using the premise that microbial mats can trap very fine grains (including magnetic grains, ubiquitous in terrestrial environments) past the angle of repose while abiogenic structures with the same topography cannot. In these stromatolites, micritic layers have a greater magnetic susceptibility than calcite fan layers, consistent with the petrographic results. In addition, organic material was mapped within the stromatolites using deep-UV native fluorescence spectroscopy, a new technique that highlights π bond-containing organic molecules and avoids problems with mineral fluorescence inherent in other fluorescent techniques. Distinct organic features were present in the micritic layers and absent in the calcite fan layers. Attempts were made to identify the specific organic compounds mapped using organic extractions and traditional Raman spectroscopy. While trace amounts of organic compounds were detected in bulk organic extractions from the stromatolite, specific compounds could not be successfully correlated to deep-UV signatures. Strong calcite fluorescence prevented the detection of organic compounds using visible Raman scattering. Thus, at the time of abstract submission the organic material present had not

  13. The coordination of sulfur in synthetic and biogenic Mg calcites: The red coral case

    Science.gov (United States)

    Perrin, J.; Rivard, C.; Vielzeuf, D.; Laporte, D.; Fonquernie, C.; Ricolleau, A.; Cotte, M.; Floquet, N.

    2017-01-01

    Sulfur has been recognized in biogenic calcites for a long time. However, its structural position is matter of debate. For some authors, sulfur is a marker of the organic matrix while it is part of the calcite structure itself for others. To better understand the place of sulfur in calcite, sulfated magnesian calcites (S-MgCalcite) have been synthetized at high pressure and temperature and studied by μ-XANES spectroscopy. S-MgCalcite XANES spectra show two different types of sulfur: sulfate (SO42-) as a predominant species and a small contribution of sulfite (SO32-), both substituting for carbonate ions in the calcite structure. To address the question of the position of sulfur in biogenic calcites, the oxidation states of sulfur in the skeleton and organic tissues of Corallium rubrum have been investigated by micro X-ray fluorescence (μ-XRF) and sulfur K-edge micro X-ray absorption near edge structure (μ-XANES) spectroscopy at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) on beamline ID21. In the skeleton, sulfur is mainly present as oxidized sulfur SO42- (+VI), plus a weak sulfite contribution. XANES spectra indicate that sulfur is inorganically incorporated as sulfur structurally substituted to carbonate ions (SSS). Although an organic matrix is present in the red coral skeleton, reduced organic sulfur could not be detected by μ-XANES spectroscopy in the skeleton probably due to low organic/inorganic sulfur ratio. In the organic tissues surrounding the skeleton, several sulfur oxidation states have been detected including disulfide (S-S), thioether (R-S-CH3), sulfoxide (SO2), sulfonate (SO2O-) and sulfate (SO42-). The unexpected occurrence of inorganic sulfate within the organic tissues suggests the presence of pre-organized organic/inorganic complexes in the circulatory system of the red coral, precursors to biomineralization ahead of the growth front.

  14. The effect of coal bed dewatering and partial oxidation on biogenic methane potential

    Science.gov (United States)

    Jones, Elizabeth J.P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

    2013-01-01

    Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

  15. Horizontal Flux of Biogenic Elements through PN Section in April 1994

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The horizontal flux of biogenic elements through PN section in April 1994 was calculated in the present paper using output of the OPYC model, which is a very general global model solving the full primitive equations forced by the atmospheric wind stress, observed heat flux, freshwater flux and cloudiness including a sea ice model both poles with rheology. However, since it is a global model, its resolution is rather coarse, less than 1°×1° horizontally and only 1 layer on continental shelf and 7 layers in the Okinawa Trough. We reconstructed the velocity profiles by ocean current modes evaluated from the hydrographic data along PN section and then used it to determine the flux of biogenic elements with the data collected during the Japanese cruise K94-04.   The results shown that the volume transport was about 33×1012cm3/s consistent with the OPYC model output, the maximum nitrate and phosphate flux densities were right on the shelf margin at the depth of about 300 m with the total fluxes 1.95×105 and 0.15×105 mol/s, respectively, the maximum dissolved oxygen and total carbon dioxide flux densities were on the surface layer near western side of the shelf margin and in the thermocline near the eastern side of the shelf margin with the total fluxes 1.43×108 L/s and 0.69×108 mol/s,respectively, through PN section in April 1994.

  16. Biogenic emissions and CO 2 gas exchange investigated on four Mediterranean shrubs

    Science.gov (United States)

    Hansen, U.; van Eijk, J.; Bertin, N.; Staudt, M.; Kotzias, D.; Seufert, G.; Fugit, J.-L.; Torres, L.; Cecinato, A.; Brancaleoni, E.; Ciccioli, P.; Bomboi, T.

    In order to investigate the impact of plant physiology on emissions of biogenic volatile organic compounds monoterpene emission rates from Rosmarinus officinalis (L.) and Pistacia lentiscus (L.) and isoprene emission rates from Erica arborea (L.) and Myrtus communis (L.) were determined. The study, an activity in the framework of BEMA (Biogenic Emissions in the Mediterranean Area), was carried out in May 1994 at Castelporziano near Rome in Italy, using a dynamic enclosure technique combined with recording CO 2 gas exchange, temperature and irradiance data. The monoterpenes dominating the emission pattern were 1,8-cineol, α-pinene and β-pinene for rosemary and α-pinene, linalool and β-pinene + sabinene for pistachio. Total monoterpene emission rates standardized to 30°C of 1.84 ± 0.24 and 0.35 ± 0.04 μg Cg -1 dw h -1 were found for rosemary and pistachio, respectively (on a leaf dry weight basis). Myrtle emitted 22.2 ± 4.9 μg C g -1 dw h -1 at standard conditions (30°C, PAR 1000 μmol photons m -2 s -1 as isoprene and erica 5.61 μg C g -1 dw h -1 The carbon loss due to terpenoid emissions per photosynthetically carbon uptake was about 0.01-0.1% for the monoterpene emitters. The isoprene emitting shrubs lost 0-0.9% of the assimilated carbon. The rapid induction of emissions in the sun after temporary shading indicates that isoprene emissions were closely linked to photosynthesis. A higher proportion of the assimilated carbon was lost as isoprene under conditions of high light and temperature compared to the morning and evening hours.

  17. 两种发酵工艺下低盐固态酱油中生物胺的变化%Changes in biogenic amines during low-salt solid-state fermentation of soy sauce by different technologies

    Institute of Scientific and Technical Information of China (English)

    钱雨林; 闫寅卓; 李兆杰; 陈晶瑜; 韩北忠

    2012-01-01

    生物胺常被作为衡量食品安全水平的标志.本研究采用高效液相色谱法分别测定2种发酵工艺下低盐固态酱油中生物胺的变化,同时检测分析发酵过程中微生物数量、水分含量、氯化钠含量的变化情况.结果表明,肠道菌的数量与组胺、酪胺的含量积累有密切关系:相较于移位发酵法,采用原池淋浇发酵工艺其发酵末期的酱醅中水分和氯化钠的含量更高;苯乙胺和腐胺是移位发酵工艺主要的生物胺,腐胺、组胺和酪胺是原池淋浇发酵工艺主要的生物胺.%The content of biogenic amines is a quality index which reflects the level of food safety. In this study, the changes in biogenic amines during low-salt solid-state fermentation of soy sauces by two different technologies, two-step fermentation and spraying-extraction fermentation, were investigated by high performance liquid chromatography (HPLC). Changes in microbial counts, water and NaCl contents during soy sauce fermentation were also detected. Results showed that the level of Enterobacteria was relevant to the accumulation of histamine and tyramine. At the end of fermentation, the water and NaCl contents in spraying-extraction fermentation were significantly higher than those in two-step fermentation. Putrescine and P-phenylethylamine were main biogenic amines produced during two-step fermentation, while putrescine, histamine and tyramine were main biogenic amines in spraying-extraction fermentation.

  18. Biomineralization of Uranium:A Simulated Experiment and Its Significance

    Institute of Scientific and Technical Information of China (English)

    MIN Maozhong; Huifang XU; L. L. BARTON; WANG Jinping; PENG Xinjian; H. WIATROWSKI

    2005-01-01

    A simulated experimental reduction of UⅥ and the synthesis of uraninite by a sulfate-reducing bacteria,Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were:35℃, pH=7.0--7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments,might have participated in the biomineralization of this uranium deposit. There is an important difference in the orderdisorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.

  19. Brookhaven Linac Isotope Producer

    Data.gov (United States)

    Federal Laboratory Consortium — The Brookhaven Linac Isoptope Producer (BLIP)—positioned at the forefront of research into radioisotopes used in cancer treatment and diagnosis—produces commercially...

  20. Spatial distribution of biogenic sulphur compounds in the Arctic aerosol collected during the AREX 2011 and 2012 Oceania ship cruises

    Science.gov (United States)

    Udisti, Roberto; Rugi, Francesco; Becagli, Silvia; Bolzacchini, Ezio; Calzolai, Giulia; Chiari, Massimo; Frosini, Daniele; Ghedini, Costanza; Marconi, Miriam; Grazia Perrone, Maria; Sangiorgi, Giorgia; Severi, Mirko; Traversi, Rita; Walczowski, Waldek; Zielinski, Timon

    2013-04-01

    The sea area between Norway and Svalbard Islands (Norwegian and Greenland Seas) is a critical site to study the effects of the climate change on the high-latitude Northern-Hemisphere regions. In particular, changes in extension and/or in the persistence of annual sea-ice, availability of nutrients and trace-elements in the biological-active marine layers and sea surface temperatures could affect the marine primary productivity and the emission into the atmosphere of dimethylsulphide (DMS), produced by phytoplankton metabolic processes. This volatile compound is oxidised in the atmosphere mainly to sulphuric acid and Methanesulphonic acid (MSA), which undergo gas-to-particle processes and form secondary sub-micrometric aerosol particles. In this way, they play a relevant role as cloud concentration nuclei (CCN), therefore controlling the climate through scattering/absorption of solar irradiation and changes in cloud coverage (and so affecting albedo). Here, we report the spatial distribution of MSA and H2SO4 measured on 12-h aerosol samples (PM10) collected during two summer cruises of the Oceania ship (AREX 2011 and 2012 oceanographic cruises). The samples were collected on Teflon filters along several marine transects starting from Tromso (Norway) to Svalbard Island and along the Western side of Svalbard Islands. S-compounds distribution was also compared with the organic carbon (OC) aerosol fraction, determined by a EC/OC thermo-optical analyser, and with the atmospheric concentration of selected carboxylic acids (measured by ion chromatography). Preliminary results on the AREX 2011 aerosol samples show two sharp maxima of non-sea-salt sulphate and MSA in June, in phase one with each other, while lower contribution of biogenic emission are recorded in the filters collected in July. Besides, no clear trend along coastal to open-sea transects is evident. Higher MSA concentrations (up to 120 ng/m3) were measured near the Norwegian coast, along the Tromso

  1. Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    S. D. D'Andrea

    2014-10-01

    Full Text Available Emissions of biogenic volatile organic compounds (BVOC have changed in the past millennium due to changes in land use, temperature and CO2 concentrations. Recent model reconstructions of BVOC emissions over the past millennium predicted changes in dominant secondary organic aerosol (SOA producing BVOC classes (isoprene, monoterpenes and sesquiterpenes. The reconstructions predicted that global isoprene emissions have decreased (land-use changes to crop/grazing land dominate the reduction, while monoterpene and sesquiterpene emissions have increased (temperature increases dominate the increases; however, all three show regional variability due to competition between the various influencing factors. These BVOC changes have largely been anthropogenic in nature, and land-use change was shown to have the most dramatic effect by decreasing isoprene emissions. In this work, we use two modeled estimates of BVOC emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on SOA formation, global aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS global aerosol microphysics model. With anthropogenic emissions (e.g. SO2, NOx, primary aerosols held at present day values and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size Dp > 80 nm (N80 of >25% in year 2000 relative to year 1000 were predicted in regions with extensive land-use changes since year 1000 which led to regional increases in direct plus indirect aerosol radiative effect of >0.5 W m−2 in these regions. We test the sensitivity of our results to BVOC emissions inventory, SOA yields and the presence of anthropogenic emissions; however, the qualitative response of the model to historic BVOC changes remains the same in all cases. Accounting for these uncertainties, we estimate millennial changes in BVOC emissions cause a global mean direct effect of between +0.022 and

  2. Effect of starter culture, spice mix and storage time and temperature on biogenic amine content of dry fermented sausages.

    Science.gov (United States)

    Komprda, T; Smělá, D; Pechová, P; Kalhotka, L; Stencl, J; Klejdus, B

    2004-08-01

    Two types of dry fermented sausage differing in spicing mixture and the diameter (low content of red pepper+diameter 80 mm, H-sausage; high content of red pepper+diameter 55 mm, P-sausage, respectively) were produced in parallel with two different starter cultures (Pediococcus pentosaceus+Staphylococcus carnosus, B-samples and S. carnosus+Staphylococcus xylosus+Lactobacillus farciminis, F-samples, respectively). The sausages were ripened 21 days and subsequently stored 91 days at the room temperature. Concentration of both most abundant amines, putrescine and tyramine (y; mg/kg DM) increased significantly (P<0.01) in HB-sausage during ripening (x; days): y=2.5+18.13x-0.3144x(2) (R(2)=0.99) and y=0.7+8.17x-0.1130x(2) (R(2)=0.99), and also during storage: y=127.3+5.123x (R(2)=0.79) and y=26.0+3.211x (R(2)=0.74), respectively. At the end of ripening, putrescine (247 mg/kg DM) and tyramine (123 mg/kg DM) content in the HB-sausage was higher (P<0.05) than in the PB-sausage (12 and 9 mg/kg DM, respectively), concentration of either of these amines was negligible (1 mg/kg DM) in either type of F-inoculated sausage. Both starter culture and sausage type influenced significantly (P<0.001) both putrescine and tyramine content in the sausage; starter accounted for 57% and 55% of total variability in putrescine and tyramine content, respectively. Due to the significant (P<0.05) increase of total aerobic counts in the HB-sausage between the end of ripening and the 7th day of storage, followed by the significant (P<0.01) increase of the sum of total biogenic amines between the end of ripening (425 mg/kg DM) and the end of storage (1029 mg/kg DM), the storage of the dry fermented sausages at the room temperature should not be recommended.

  3. Producing Against Poverty

    NARCIS (Netherlands)

    Ypeij, Annelou

    2000-01-01

    Producing against Poverty is an anthropological research on micro-entrepreneurs in Lima, Peru. It analyses the way micro-producers accumulate capital. The anthropological approach of the book starts with an analysis of the daily lives of the micro-producers. Its gender approach makes a comparison be

  4. Multi-model simulation of CO and HCHO in the Southern Hemisphere: comparison with observations and impact of biogenic emissions

    Science.gov (United States)

    Zeng, G.; Williams, J. E.; Fisher, J. A.; Emmons, L. K.; Jones, N. B.; Morgenstern, O.; Robinson, J.; Smale, D.; Paton-Walsh, C.; Griffith, D. W. T.

    2015-07-01

    We investigate the impact of biogenic emissions on carbon monoxide (CO) and formaldehyde (HCHO) in the Southern Hemisphere (SH), with simulations using two different biogenic emission inventories for isoprene and monoterpenes. Results from four atmospheric chemistry models are compared to continuous long-term ground-based CO and HCHO column measurements at the SH Network for the Detection of Atmospheric Composition Change (NDACC) sites, the satellite measurement of tropospheric CO columns from the Measurement of Pollution in the Troposphere (MOPITT), and in situ surface CO measurements from across the SH, representing a subset of the National Oceanic and Atmospheric Administration's Global Monitoring Division (NOAA GMD) network. Simulated mean model CO using the Model of Emissions of Gases and Aerosols from Nature (v2.1) computed in the frame work of the Land Community Model (CLM-MEGANv2.1) inventory is in better agreement with both column and surface observations than simulations adopting the emission inventory generated from the LPJ-GUESS dynamical vegetation model framework, which markedly underestimate measured column and surface CO at most sites. Differences in biogenic emissions cause large differences in CO in the source regions which propagate to the remote SH. Significant inter-model differences exist in modelled column and surface CO, and secondary production of CO dominates these inter-model differences, due mainly to differences in the models' oxidation schemes for volatile organic compounds, predominantly isoprene oxidation. While biogenic emissions are a significant factor in modelling SH CO, inter-model differences pose an additional challenge to constrain these emissions. Corresponding comparisons of HCHO columns at two SH mid-latitude sites reveal that all models significantly underestimate the observed values by approximately a factor of 2. There is a much smaller impact on HCHO of the significantly different biogenic emissions in remote regions

  5. Evolution of free amino acids, biogenic amines and n-nitrosoamines throughout ageing in organic fermented beef

    Directory of Open Access Journals (Sweden)

    Karolina M. Wójciak

    2016-06-01

    Full Text Available Background. In recent years, interest in uncured meat products has grown and studies were carried out on the use of substances which could replace nitrites, such as acid whey. In spite of this problem in fermented meat products, there is no information regarding the effects of prolonged ageing on the formation of chemi- cal (nitrosoamines, biogenic amines, secondary lipid oxidation products and microbiological (L. monocy- togenes, S. aureus, OLD toxicants in fermented beef marinated with acid whey. The aim of this study was to determine the selected pathogenic bacteria, biogenic amines, N-nitrosamines contents in fermented beef subjected to extended ageing. Material and methods. In this study, selected pathogenic bacteria, N-nitrosamines, biogenic amines, amino acids, TBARS values changes during the ageing of fermented beef marinated with acid whey were analyzed in 0-, 2- and 36-month-old samples. Results. The pH values of fermented beef aged for 2 months (5.68, 5.49 and 5.68 respectively were sig- nificantly lower (p < 0.05 than those obtained after the end of the manufacturing ripening period (5.96, 5.97 and 5.74 respectively, which confirmed the effectiveness of the fermentation process of acidification on beef. The high Lactic Acid Bacteria content (5.64–6.30 log cfu/g confirmed this finding. Histamine was not detected in either of the products. The highest concentration of total biogenic amine (i.e. 1159.0 mg/kg was found in fermented beef marinated with acid whey, whereas a total of only 209.8 mg/kg, was observed in control beef with nitrate and nitrite. N-nitrosamines were not detected in any of the ageing beef samples. Conclusion. In this study, marinating beef in acid whey did not inhibit the production of biogenic amines in the samples analyzed. The high concentration of FAAs, the potential precursor of BA, could lead to intense peptidase activity. The results obtained indicate that biogenic amines are not direct precursors

  6. A method for the evaluation of a system for the disposal and use of biogenic wastes and farm manure; Vorstudie fuer eine Methode zur Bewertung der Entsorgungs- und Nutzungsverfahren von biogenen Abfaellen und Hofduenger. Entwicklung der Methodik und Anwendung auf ausgewaehlte Technologien

    Energy Technology Data Exchange (ETDEWEB)

    Baettig, M.; Klingler, G.; Dettli, R. [econcept AG, Zuerich (Switzerland); Frischknecht, R.; Tuchschmid, M. [ESU-Services Ltd., fair consulting in sustainability, Uster (Switzerland)

    2009-06-15

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) deals with the evaluation of a system for the disposal and use of biogenic wastes and farm dung. The principle aim of the study was to develop a method for the evaluation of the various methods for the disposal and use of biogenic wastes and the manure produced in agriculture. A further aim was the exemplary use of the method on a selection of waste disposal methods and the drawing of initial conclusions from the ecological, economic and social points of view. The report provides details on the biomass fractions examined and their energy content. The fundamentals on which the development of the methods used are based are described. Test use of the multi-criterion analysis developed is discussed as is sensitivity analysis. Finally conclusions concerning the evaluation are presented and recommendations are made. The appendix to the report contains details on the comprehensive questionnaire used to collect information and the results of an on-line survey on the weighting of the criteria. Also, fact sheets on the 24 disposal and usage variants examined and an overview of disposal and collection costs are presented. The appendix also contains result tables on the use of the method for biogenic wastes, sewage sludge, farm manure, wood wastes and scrap wood.

  7. Multiplex PCR for colony direct detection of Gram-positive histamine- and tyramine-producing bacteria.

    Science.gov (United States)

    Coton, Emmanuel; Coton, Monika

    2005-12-01

    Formation of biogenic amines (BA) may occur in fermented foods and beverages due to the amino acid decarboxylase activities of Gram-positive bacteria. These compounds may cause food poisoning and therefore could imply food exportation problems. A set of consensual primers based on histidine decarboxylase gene (hdc) sequences of different bacteria was designed for the detection of histamine-producing Gram-positive bacteria. A multiplex PCR based on these hdc primers and recently designed primers targeting the tyrosine decarboxylase (tyrdc) gene was created. A third set of primers targeting the 16S rRNA gene of eubacteria was also used as an internal control. This multiplex PCR was performed on extracted DNA as well as directly on cell colonies. The results obtained show that this new molecular tool allowed for the detection of Gram-positive histamine- and/or tyramine-producing bacteria. The use of this molecular tool for early and rapid detection of Gram-positive BA-producing bacteria is of interest in evaluating the potential of cultured indigenous strains to produce biogenic amines in a fermented food product as well as to validate the innocuity of potential starter strains in the food industry.

  8. Clinical and radiographic evaluation of Bio-Gen with biocollagen compared with Bio-Gen with connective tissue in the treatment of class II furcation defects: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Niloofar Jenabian

    2013-09-01

    Full Text Available OBJECTIVE: Treatment of furcation defects are thought to be challenging. The purpose of this study was to evaluate the clinical and radiographic parameters of Bio-Gen with Biocollagen compared with Bio-Gen with connective tissue in the treatment of Class II furcation defects. MATERIAL AND METHODS: In this clinical trial, 24 patients with Class II furcation defect on a buccal or lingual mandibular molar were recruited. After oral hygiene instruction, scaling and root planing and achievement of acceptable plaque control, the patients were randomly chosen to receive either connective tissue and Bio-Gen (case group or Biocollagen and Bio-Gen (control group. The following parameters were recorded before the first and re-entry surgery (six months later: vertical clinical attachment level (VCAL, gingival index (GI, plaque index (PI, horizontal probing depth (HPD, vertical probing depth (VPD, gingival recession (GR, furcation vertical component (FVC, furcation to alveolar crest (FAC, fornix to base of defect (FBD, and furcation horizontal component (FHC were calculated at the time of first surgery and during re-entry. A digital periapical radiograph was taken in parallel before first surgery and re-entry. The radiographs were then analyzed by digital subtraction. The differences with p value <0.05 were considered significant. RESULTS: Only the mean changes of FAC, FHC, mean of FHC, FBD in re-entry revealed statistically significant differences between the two groups. HPD, VPD, FBD, FAC, and FHC showed statistically significant differences after 6 months in the case group. However, in the control group, statistically significant differences were found in GR and HPD. We did not observe any significant difference in radiographic changes among the two groups. CONCLUSION: The results of this trial indicate that better clinical outcomes can be obtained with connective tissue grafts in combination with bone material compared with a resorbable barrier with bone

  9. Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season

    Science.gov (United States)

    Whitehead, James D.; Darbyshire, Eoghan; Brito, Joel; Barbosa, Henrique M. J.; Crawford, Ian; Stern, Rafael; Gallagher, Martin W.; Kaye, Paul H.; Allan, James D.; Coe, Hugh; Artaxo, Paulo; McFiggans, Gordon

    2016-08-01

    The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the properties of the natural biogenic aerosol particles over the Amazon rainforest is key to understanding their influence on regional and global climate. While there have been a number of studies during the wet season, and of biomass burning particles in the dry season, there has been relatively little work on the transition period - the start of the dry season in the absence of biomass burning. As part of the Brazil-UK Network for Investigation of Amazonian Atmospheric Composition and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Amazon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before significant biomass burning occurs in the region. Median particle number concentrations were 266 cm-3, with size distributions dominated by an accumulation mode of 130-150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an enhancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry season, when significant biomass burning takes place. Submicron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was dominated by organic material (around 81 %). Aerosol hygroscopicity was probed using measurements from a hygroscopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ, was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent

  10. Chemistry of new particle growth in mixed urban and biogenic emissions – insights from CARES

    Energy Technology Data Exchange (ETDEWEB)

    Setyan, Ari; Song, Chen; Merkel, M.; Knighton, M.; Onasch, Timothy B.; Canagaratna, M. R.; Worsnop, Douglas R.; Wiedensohler, A.; Shilling, John E.; Zhang, Qi

    2014-07-01

    plumes. In addition, the concentrations of species representative of urban emissions (e.g., black carbon,CO, NOx, and toluene) were significantly higher whereas thephoto-oxidation products of biogenic VOCs (volatile organic compounds) and the biogenically influenced SOA also increased moderately during the NPE days compared to the non-event days. These results indicate that the frequently occurring NPEs over the Sacramento and Sierra Nevada regions were mainly driven by urban plumes from Sacramento and the San Francisco Bay Area, and that the interaction of regional biogenic emissions with the urban plumes has enhanced the new particle growth. This finding has important implications for quantifying the climate impacts of NPEs on global scale.

  11. Study of Biogenic Volatile Organic Compounds at the French Guiana Tropical Forest

    Science.gov (United States)

    Corain Lopes, Paula Regina; Guenther, Alex; Turnipseed, Andrew; Bonal, Damien; Serça, Dominique; Burban, Benôit; Siebicke, Lukas; Emmons, Louisa; Bustillos, José Oscar W. V.

    2013-04-01

    Biogenic volatile organic compound (BVOCs) emissions play an important role in regional air quality and global atmospheric chemistry. In addition, these natural VOC emissions serve important biological functions including attracting and repelling pollinators and herbivores. Some biological organisms use ambient air as a communication medium and the oxidation of these compounds brings about the concentration gradients sensed by insects and other organisms. Isoprene is the predominant BVOC emitted by vegetation and tropical forests are the dominant global source. This compound is very reactive in the atmosphere and contributes to the reactions that control tropospheric oxidant concentrations and thus the concentrations and lifetimes of longer-lived species. This paper presents a study on the seasonal variations in isoprene and some other significant BVOCs such as α-pinene, β-pinene, limonene, e-β ocimene and longifolene, measured at the Guyaflux Tower located in a wet tropical forest in Paracou French Guiana (5o16´54´´N, 52o54´44´´W), during the year of 2011, using the Relaxed Eddy Accumulation technique at approximately 20 meters high above the canopy. The results show a lower concentration of isoprene during the month of February and March which correspond to the wet season with an average of 0,545 μg/m3 and 0,341 μg/m3, respectively followed by a slight increase in middle April (still wet season) and a higher concentration later in mid-June. The same behavior was observed for α-pinene with higher concentrations for the same periods as isoprene however with a smaller increase. All the other compounds had concentrations below 1 μg/m3during the whole year. The monoterpene, e-β ocimene, was observed and is known as a stress compound but the vegetation at the site did not face any known severe stress condition such as excessive drought or flooding. Concerning the fluxes, the results showed that just a small amount of BVOCs were deposited by wet or dry

  12. Simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell cultures and in sub-regions of guinea pig brain

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie Voigt; Hansen, Stine Normann; Tveden-Nyborg, Pernille

    2016-01-01

    In the present paper, we describe a validated chromatographic method for the simultaneous quantification of monoamine neurotransmitters and their biogenic metabolites intracellularly and extracellularly in primary neuronal cell culture and in sub-regions of the guinea pig brain. Electrochemical...

  13. Image analysis techniques and gray-level co-occurrence matrices (GLCM) for calculating bioturbation indices and characterizing biogenic sedimentary structures

    Science.gov (United States)

    Honeycutt, Chris Ebey; Plotnick, Roy

    2008-11-01

    Aspects of texture and structure in a bed resulting from bioturbation can provide valuable information about the ecology and environment at the time of deposition. However, not only the degree of bioturbation, but the structure of the burrows is important for interpreting biogenic fabrics. Here, image analysis is applied to real and artificial images of biogenic sedimentary structures. Image segmentation was applied to images of Middle Ordovician biogenic sedimentary structures from Dixon, Illinois (Pecatonica Formation), isolating the biogenic sedimentary structures. A gray-level co-occurrence matrix (GLCM) is calculated from the segmented image and eight artificial images representing different levels of image noise. Texture measures were calculated from the GLCMs and compared with identify scale and directional structural differences between the images. Principal component analysis was used to statistically group the images. Artificial images were found to be distinguishable from the real images by GLCM texture measures, and the real images differed most significantly at the largest scales.

  14. Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes

    Directory of Open Access Journals (Sweden)

    F. Fripiat

    2011-09-01

    Full Text Available Silicon isotopic signatures (δ30Si of water column silicic acid (Si(OH4 were measured in the Southern Ocean, along a meridional transect from South Africa (Subtropical Zone down to 57° S (northern Weddell Gyre. This provides the first reported data of a summer transect across the whole Antarctic Circumpolar Current (ACC. δ30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional water transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determine different mixing interfaces: the Antarctic Surface Water (AASW, the Antarctic Intermediate Water (AAIW, and thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the δ30Si alteration of the mixing products and with the exception of AASW, all mixing interfaces have a highly Si-depleted mixed layer end-member. These processes deplete the silicic acid AASW concentration northward, across the different interfaces, without significantly changing the AASW δ30Si composition. By comparing our new results with a previous study in the Australian sector we show that during the circumpolar transport of the ACC eastward, the δ30Si composition of the silicic acid pools is getting slightly, but significantly lighter from the Atlantic to the Australian sectors. This results either from the dissolution of biogenic silica in the deeper layers and/or from an isopycnal mixing with the deep water masses in the different oceanic basins: North Atlantic Deep Water in the Atlantic, and Indian Ocean deep water in the Indo-Australian sector. This isotopic trend is further transmitted to the subsurface waters, representing mixing interfaces between the surface and deeper layers.

  15. A comparison of biogenic iron quotas during a diatom spring bloom using multiple approaches

    Directory of Open Access Journals (Sweden)

    A. L. King

    2012-02-01

    Full Text Available Biogenic Fe quotas were determined using three distinct techniques on samples collected concurrently in the subtropical Pacific Ocean east of New Zealand. Fe quotas were measured using radioisotope uptake experiments (24 h incubation, bulk filtration and analysis by inductively-coupled plasma mass spectrometer (ICPMS, and single-cell synchrotron x-ray fluorescence (SXRF analysis over a sixteen-day period (year days 263 to 278 of 2008 during a quasi-Lagrangian drifter experiment that tracked the evolution of the annual spring diatom bloom within a counter-clockwise open-ocean eddy. Overall, radioisotope uptake-determined Fe quotas (washed with oxalate reagent to remove extracellular Fe were the lowest (0.5–1.0 mmol Fe:mol P; 4–8 μmol Fe:mol C, followed by single-cell Fe quotas (2.3–7.5 mmol Fe:mol P; 17–57 μmol Fe:mol C, and the highest and most variable quotas were from the bulk filtration ICPMS approach that used the oxalate reagent wash, corrected for lithogenic Fe using Al (0.8–21 mmol Fe:mol P; 4–136 μmol Fe:mol C. During the evolution of the spring bloom within the eddy (year days 263 to 272, the surface mixed layer inventories of particulate biogenic elements (C, N, P, Si and chlorophyll increased while Fe quotas estimated from all three approaches exhibited a general decline. After the onset of the bloom decline, the drogued buoys exited the eddy center (days 273 to 277. Fe quotas returned to pre-bloom values during this part of the study. Our standardized and coordinated sampling protocols reveal the general observed trend in Fe quotas: ICPMS > SXRF > radioisotope uptake. We discuss the inherent differences between the techniques and argue that each technique has its individual merits and uniquely contributes to the characterization of the oceanic particulate Fe pool.

  16. Neodymium isotopes in biogenic carbonates: reliable archives of ɛNd

    Science.gov (United States)

    Montagna, P.; Goldstein, S. L.; Taviani, M.; Frank, N.; McCulloch, M. T.

    2010-12-01

    Neodymium isotope (143Nd/144Nd) compositions from dispersed authigenic ferromanganese oxide fraction in marine sediments, ferromanganese crusts, foraminiferal shells and fossil fish teeth are employed to trace provenance and water mass mixing in the past, having the advantage of not being fractionated by biological processes in the water column. In the modern ocean the different water masses ultimately derive their ɛNd values through continental weathering, erosion and particle-seawater interactions. This geochemical tracer has been only recently applied to scleractinian deep-water coral skeletons sourced from various sites and depths in the Atlantic ocean. Aragonitic corals can be precisely dated by U-series, potentially providing century-long records of intermediate and bathyal zone variability at sub-decadal resolution. Motivated by these recent findings we have investigated the Nd isotopic compositions of living specimens of various calcifying organisms collected in two key locations of the Mediterranean Sea and in the Southern Ocean. In particular, we analyzed several specimens of the aragonitic deep-water corals Desmophyllum dianthus, Lophelia pertusa, Madrepora oculata, Flabellum impensum, the temperate coral Cladocora caespitosa, the calcitic gorgonian coral Corallium rubrum, the bivalves Glans aculeata and Karnekampia bruei and the polychate Serpula vermicularis. Most of the samples were retrieved from the Strait of Sicily and the Southern Adriatic Sea at different water depths. Ten seawater samples from three new profiles in the Mediterranean were also collected at the same locations and depths, offering a unique opportunity to compare the Nd isotopic composition of biogenic carbonates directly with the surrounding ambient seawater. The Mediterranean Sea is particularly suited for this comparison exercise since it is characterized by water masses displaying a large range of ɛNd values, from -10.5 in the Western Mediterranean to -4.8 in the Eastern

  17. Silicon pool dynamics and biogenic silica export in the Southern Ocean, inferred from Si-isotopes

    Directory of Open Access Journals (Sweden)

    F. Fripiat

    2011-03-01

    Full Text Available Water column silicon isotopic signatures (δ30Si of silicic acid (Si(OH4 in the Southern Ocean were measured along a meridional transect from South Africa (Subtropical Zone down to 57° S (northern Weddell Gyre. These data are the first reported for a summer transect across the whole Antarctic Circumpolar Current (ACC. δ30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determined different mixing interfaces between ACC water masses: the Antarctic Surface Water (AASW, the Antarctic Intermediate Water (AAIW, and the thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the δ30Si alteration of the mixing products. With the exception of AASW, all mixing interfaces have a highly Si-depleted mixed layer end-member. These processes deplete the silicic acid AASW concentration across the different interfaces northward without significantly changing the AASW δ30Si. By comparing our new results with a previous study in the Australian sector we show that during the circumpolar transport of the ACC eastward, there is a slight but significant Si-isotopic lightening of the silicic acid pools from the Atlantic to the Australian sectors. This results either from the dissolution of biogenic silica in the deeper layers and/or from an isopycnal mixing with the deep water masses in the different oceanic basins: North Atlantic Deep Water in the Atlantic, and Indian Ocean deep water in the Indo-Australian sector. This eastward lightening is further transmitted to the subsurface waters, representing mixing interfaces between the surface and deeper layers.

    Using the Si

  18. Virus disinfection in water by biogenic silver immobilized in polyvinylidene fluoride membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gusseme, B.D.; Fitts, J.; Hennebel, T.; Christiaens, E.; Saveyn, H.; Verbeken, K.; Boon, N.; Verstraete, W.

    2011-03-01

    The development of innovative water disinfection strategies is of utmost importance to prevent outbreaks of waterborne diseases related to poor treatment of (drinking) water. Recently, the association of silver nanoparticles with the bacterial cell surface of Lactobacillus fermentum (referred to as biogenic silver or bio-Ag{sup 0}) has been reported to exhibit antiviral properties. The microscale bacterial carrier matrix serves as a scaffold for Ag{sup 0} particles, preventing aggregation during encapsulation. In this study, bio-Ag{sup 0} was immobilized in different microporous PVDF membranes using two different pre-treatments of bio-Ag{sup 0} and the immersion-precipitation method. Inactivation of UZ1 bacteriophages using these membranes was successfully demonstrated and was most probably related to the slow release of Ag{sup +} from the membranes. At least a 3.4 log decrease of viruses was achieved by application of a membrane containing 2500 mg bio-Ag{sub powder}{sup 0} m{sup -2} in a submerged plate membrane reactor operated at a flux of 3.1 L m{sup -2} h{sup -1}. Upon startup, the silver concentration in the effluent initially increased to 271 {micro}g L{sup -1} but after filtration of 31 L m{sup -2}, the concentration approached the drinking water limit (= 100 {micro}g L{sup -1}). A virus decline of more than 3 log was achieved at a membrane flux of 75 L m{sup -2} h{sup -1}, showing the potential of this membrane technology for water disinfection on small scale. In biogenic silver, silver nanoparticles are attached to a bacterial carrier matrix. Bio-Ag{sup 0} was successfully immobilized in PVDF membranes using immersion-precipitation. The antiviral activity of this material was demonstrated in a plate membrane reactor. The antimicrobial mechanism was most probably related to the slow release of Ag{sup +} ions. The membranes can be applied for treatment of limited volumes of contaminated water.

  19. New Environmentalconditions Responsible for the amount of mg Incorporated in Biogenic Carbonates

    Science.gov (United States)

    Zuddas, P.; Cherchi, A.; DeGiudici, G. B.; Buosi, C.

    2012-12-01

    The composition of carbonate minerals formed in past and present oceans is assumed to be significantly controlled by temperature and seawater composition. Several kinetic laboratory investigations have suggested that the temperature is kinetically responsible for the amount of Mg incorporated in both abiotic and biogenic calcites and that variation of kinetic reaction mechanism resulting from the temperature changes are correlated with the variable amount of Mg incorporated in calcites. These results explain why in present-day marine carbonates low-Mg calcite cements are mainly associated with cool water while high-Mg carbonates are dominantly found in warm-water environments. An apparent inverse relationship between the global average paleo-temperature and the Mg/Ca ratio is however observed in the past formed marine carbonate. This apparent contradiction has been interpreted as resulting from a possible changing in the relative seawater geochemical cycles of these cations. Recent monitoring of costal areas in presence of heavy metals and CO2 released from industrial polluted area reveals the presence of porcelanaceous miliolids infested by microscopic boring microflora (cyanobacteria, algae and fungi). Here, benthonic foraminifera have Mg/Ca molar ratio by one order of magnitude higher when compared to the average value of the same genus living under uncontaminated environments. A similar behaviour has been found for Zn, Cd and Pb. In these contaminated environments, temperature and average major seawater composition remain constant, while PCO2 partial pressure (estimated by pH and alkalinity using the ion pairing model) is 3-5 times higher than the average for the open sea nearby. Geochemical models predicts that CO2 increase is affecting carbonate saturation state of surface water in the twenty-first century indicating that calcareous organisms may have difficulty calcifying leading to production of weaker skeletons and greater vulnerability to erosion. The

  20. Biogenic Volatile Organic Compound Emission Rates From Urban Vegetation in Southeast China

    Science.gov (United States)

    Baker, B.; Graessli, M.; Bai, J.; Huang, A.; Li, N.; Guenther, A.

    2005-12-01

    Currently, the country of China is growing economically at an extraordinary pace. With this growth comes an increase in emissions of anthropogenic pollutants such as hydrocarbons and nitrogen oxides from factories and vehicles. To accurately determine the effects of these pollutants on regional ozone production, and to best determine mitigation strategies, biogenic volatile organic compound (BVOC) emissions must be considered in regional atmospheric chemistry models. To date, few studies have been carried out to determine BVOC emission factors for plant species that occur in China. Considering that approximately 20% of the world's population resides in this region, it is important to develop accurate databases for BVOC emissions for the country of China. This experiment took place during May and June of 2005 and was based in the Fairy Lake Botanical Gardens (FLBG) located to the northeast of the city of Shenzhen. The city of Shenzhen is located in southeast China in Guangdong province. The city was designated a 'special economic zone' in 1980 and has experienced intense population and economic growth ever since. The dense city is surrounded by hilly rural areas of forest on three sides, and Hong Kong to the south. The purpose of the experiment was to evaluate emissions of BVOC from plants that are important to the Shenzhen region as well as to southeastern China. Over 150 species of plants were screened for emissions of isoprene and monoterpenes. These species include most of the dominant trees and shrubs planted in the Shenzhen area. Samples were collected at the FLBG as well as at various locations around the city of Shenzhen. BVOC emission samples were collected and analyzed in one of two ways. First, a Teflon enclosure was placed over a plant's branch with a constant flow of ambient air passing through the enclosure. Samples were then pumped into a Teflon bag for analysis. Samples were analyzed within 30 minutes by gas chromatography (GC) with either a photo

  1. Investigation of formation and ageing of biogenic secondary aerosols by soft ionization aerosol mass spectrometry

    Science.gov (United States)

    Müller, Lars; Reinnig, Marc-Christopher; Vogel, Alexander; Mentel, Thomas; Tillmann, Ralf; Schlosser, E.; Wahner, Andreas; Donahue, Neil; Saathoff, Harald; Hoffmann, Thorsten

    2010-05-01

    The knowledge of the chemical composition of secondary organic aerosol is one essential key to understand the significance and fate of SOA in the atmosphere. However, the chemical evolution of SOA, from the very first condensing/nucleating molecules to the final oxidation products is still insufficiently understood and object of current research [1-3]. Consequently, the formation and photochemical ageing of secondary organic aerosol (SOA) was investigated in a series of reaction chamber experiments by applying on-line aerosol mass spectrometry (atmospheric pressure chemical ionization mass spectrometry (APCI/MS)) as well as off-line high performance liquid chromatography mass spectrometry (HPLC-MS). In a set of experiments, performed in the large outdoor reaction chamber SAPHIR (Jülich, Germany), SOA was generated from a boreal mixture of biogenic VOCs. During a two-day experiment the generated biogenic SOA was exposed to OH-radicals and the temporal evolution of the chemical composition was characterized. The applied on-line MS method not only provides highly time resolved chemical information (such as an AMS) but also allows molecular identification/quantification of specific marker compounds. Several first and higher generation BSOA products were identified. Among the higher generation products, especially a tricarboxylic acid (3-methyl-1,2,3-butanetricarboxylic acid) [2] was observed as an eye-catching oxidative processing marker. A more detailed investigation of hydroxyl radical induced SOA aging at the AIDA chamber facility in Karlsruhe, again using terpenes as SOA precursors, clearly showed that the formation of the tricarboxylic acid takes place in the gas phase by the reaction of semivolatile first generation products and hydroxyl radicals. Actually, there were no indications for OH induced oxidation of compounds in the condensed phase. The consequences of these results will be discussed in the contribution. 1. Rudich, Y., N.M. Donahue, and T.F. Mentel

  2. In Vitro Investigation of Bioactive Glass-Ceramic Composites Based on Biogenic Hydroxyapatite or Synthetic Calcium Phosphates

    Science.gov (United States)

    Pinchuk, Nataliia; Parkhomey, Oleksandr; Sych, Olena

    2017-02-01

    This in vitro investigation of the behavior of two types of calcium phosphate glass ceramics on the basis of phosphates of biogenic or synthetic origin prepared from initial mixtures with different particle size has revealed that some different factors affect the behavior, namely the phase composition of composite, fraction of open porosity, and average diameter of pore channels. It was established that the solubility of the composites on the basis of synthetic calcium phosphates and glass after 2 and 7 days contact with saline composites is the highest among the materials under study. First of all, this fact is related to the peculiarities of their phase composition, high fraction of open porosity, and high permeability. As for biogenic hydroxyapatite/glass materials, their solubility is several times lower in spite of close total porosity. The particle size of initial mixture practically does not affect the material solubility; the latter is only slightly lower for smaller particles.

  3. Chlorophyll a in suspended particulate matter of the Caspian Sea as an indicator of biogenic sedimentation conditions

    Science.gov (United States)

    Kravchishina, M. D.; Klyuvitkin, A. A.; Pautova, L. A.; Politova, N. V.; Lein, A. Yu.; Lisitzin, A. P.

    2015-11-01

    The conditions of biogenic sedimentation (concentration of chlorophyll a (chl a), particulate organic carbon (POC), and its isotope composition (δ13CPOC)), as well as the quantitative characteristics of phytoplankton, and the total concentration of suspended particulate matter have been studied in the Caspian Sea in May and June 2012. The vertical (from the surface layer to bottom) distribution and precipitation of the biogenic component of suspended particulate matter have been determined. It was found that only 5% of the particulate matter and around 3% of POC reached the Middle Caspian after passing through a marginal filter (Volga River delta-Northern Caspian). The subsurface chl a maximum layer (around 20-60 m) with a cold-water phytoplankton community was revealed in the Middle and Southern Caspian. The subsurface region of accumulation of chl a and phytoplankton in the subthermocline layer has been extended from the southern periphery of the Derbent Depression to the Absheron Sill.

  4. Changes in the Content of Biogenic Amines and Fatty Acids in High Pressure-Processed Carp Flesh (Cyprinus carpio).

    Science.gov (United States)

    KříŽek, Martin; Matějkoá, Kateřina; Dadáková, Eva; Špička, Jiří; Vácha, František; Vrchotová, NaděŽda

    2015-08-01

    Biogenic amine and fatty acid contents were determined in vacuum-packed fillets of common carp (Cyprinus carpio). Samples were pressure treated at 300 and 500 MPa and were stored at 3.5 and 12°C for up to 28 days (control, 0 MPa) and 70 days (pressure-treated). The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine, and phenylethylamine) were determined. Putrescine and cadaverine were influenced by all factors (temperature, pressurization level, and time of storage). Tyramine content was the most sensitive indicator of the improper status of sample; levels exceeding 10 mg/kg indicated both the loss of meat freshness and temperature abuse, in spite of persisting good sensory indices. Neither storage temperature nor pressurization level had a statistically important effect on the contents of fatty acids. Only polyunsaturated fatty acids decreased slightly if the storage time exceeded 42 days.

  5. Nitrogen Oxide biogenic emissions from soils: impact on NOx and ozone formation in West Africa during AMMA (African Monsoon Multidisciplinary Analysis)

    OpenAIRE

    2007-01-01

    International audience; Nitrogen Oxide biogenic emissions from soils are driven by soil and environmental parameters. The relationship between these parameters and NO fluxes is highly non linear. A new algorithm, based on a neural network calculation, is used to reproduce the NO biogenic emissions in West Africa during the AMMA campaign, in August 2006. It has been coupled in the surface scheme of a coupled chemistry dynamics model to estimate the impact of the NO emissions on NOx and O3 form...

  6. MS/MS studies for the selective detection of isomeric biogenic VOCs using a Townsend Discharge Triple Quadrupole Tandem MS and a PTR-Linear Ion Trap MS

    Directory of Open Access Journals (Sweden)

    M. Müller

    2009-08-01

    Full Text Available We performed MS/MS investigations of biogenic volatile organic compounds (BVOC using a triple quadrupole tandem mass spectrometer (QqQ-MS equipped with a Townsend Discharge ion source and a Proton Transfer Reaction Linear Ion Trap (PTR-LIT mass spectrometer. Both instruments use H2O chemical ionization to produce protonated molecular ions. Here we report a study of the application of these instruments to determine methyl vinyl ketone (MVK and methacrolein (MA