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Sample records for spoiling bacteria electronic

  1. Sensitivity of spoiling and pathogen food-related bacteria to Origanum vulgare L. (Lamiaceae) essential oil

    OpenAIRE

    Souza,Evandro Leite de; Stamford,Tânia Lúcia Montenegro; Lima,Edeltrudes de Oliveira

    2006-01-01

    Origanum vulgare L. (oregano), Lamiaceae, has been known as plant specie with prominent biological properties for a long time. This study aimed to evaluate the antibacterial activity of Origanum vulgare essential oil on various Gram-positive and Gram-negative spoiling and/or pathogen food-related bacteria, as well as to observe its antimicrobial effectiveness in a food conservation micromodel. The results showed a strong antibacterial activity of the assayed essential oil noted by large growt...

  2. Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

    Science.gov (United States)

    Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

    2016-10-01

    Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.

  3. Generating femtosecond X-ray pulses using an emittance-spoiling foil in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y., E-mail: ding@slac.stanford.edu; Coffee, R.; Decker, F.-J.; Emma, P.; Field, C.; Huang, Z.; Krejcik, P.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Maxwell, T. J.; Turner, J. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Behrens, C. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg (Germany); Helml, W. [Technische Universität München, James-Franck-Straße 1, 85748 Garching (Germany)

    2015-11-09

    Generation of femtosecond to sub-femtosecond pulses is attracting much attention in X-ray free-electron laser user community. One method is to use a slotted, emittance-spoiling foil which was proposed before (P. Emma et al., Phys. Rev. Lett. 92, 074801 (2004)) and has been widely used at the Linac Coherent Light Source. Direct experimental characterization of the slotted-foil performance was previously unfeasible due to a lack of appropriate diagnostics. With a recently installed X-band radio-frequency transverse deflector, we are able to characterize the electron bunch spoiling effect and X-ray pulse when using the slotted foil. We show that few-femtosecond X-ray pulses are generated with flexible control of the single-pulse duration or double-pulse separation with comparison to the theoretical model.

  4. Electron transport chains of lactic acid bacteria

    NARCIS (Netherlands)

    Brooijmans, R.J.W.

    2008-01-01

    Lactic acid bacteria are generally considered facultative anaerobic obligate fermentative bacteria. They are unable to synthesize heme. Some lactic acid bacteria are unable to form menaquinone as well. Both these components are cofactors of respiratory (electron transport) chains of prokaryotic

  5. Symbiont effect of Rhizobium bacteria and vesicular arbuscular mycorrhizal fungi on Pisum sativum in recultivated mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Biro, B.; Voros, I.; Kovespechy, K.; Szegi, J. (Hungarian Academy of Sciences, Budapest (Hungary). Soil Science and Agricultural Chemistry Research Institute)

    The frequency (F%) of spontaneous endomycorrhizal fungal infection (AMF) and the root modulation of Pisum sativum L, was studied after 8 and 15 years of recultivation in 4 soils (andesitic tuff yellow sand, yellow clay, and grey clay) disturbed by mining activities. The effects of Rhizobium inoculation and the interaction of both microsymbionts with plant production were also examined along with humus content and the humus stability coefficient, in the following variations: control, NPK fertilizer, NPK+lignite, NPK+straw and sewage sludge. Dump spoils originating from deep geological layers were poor in organic materials. After 12 years of recultivation, the humus content increased significantly. No such increase was noted in grey clay and the natural, brown forest soil used as an undisturbed (control) sample. The degradation of soils by mining brings about a decrease in the rhizobial and mycorrhizal population, so the number of spontaneous Rhizobium nodules is relatively low and does not influence the yield of peas. Inoculation with a selected effective strain of Rhizobium leguminosarum bv. viceae, however, enhanced dry matter production in these microbiologically degraded soils. Although the frequency of AMF infection was also higher after rhizobial inoculation, no positive correlation was found between dry matter production of peas and the F% of AMF. Spoils treated with lignite, straw, and sewage sludge had an especially high level of spontaneous mycorrhizal populations, indicating that organic materials had a favorable effect on the recultivation processes and fertility of mine spoils.

  6. Photocatalytic inactivation of bacteria from spoiled raw chicken carcasses in aqueous suspensions by TiO2 nanoparticles

    Science.gov (United States)

    Bacterial spoilage is a major cause of reduced shelf life of fresh poultry; therefore, decreasing contamination by spoilage bacteria could increase the shelf life of these products. Titanium dioxide (TiO2) nanoparticles in the presence of UVA light possess antibacterial activities towards several ba...

  7. Bacteria classification using Cyranose 320 electronic nose

    Directory of Open Access Journals (Sweden)

    Gardner Julian W

    2002-10-01

    Full Text Available Abstract Background An electronic nose (e-nose, the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds. Method Linear Principal Component Analysis (PCA method was able to classify four classes of bacteria out of six classes though in reality other two classes were not better evident from PCA analysis and we got 74% classification accuracy from PCA. An innovative data clustering approach was investigated for these bacteria data by combining the 3-dimensional scatter plot, Fuzzy C Means (FCM and Self Organizing Map (SOM network. Using these three data clustering algorithms simultaneously better 'classification' of six eye bacteria classes were represented. Then three supervised classifiers, namely Multi Layer Perceptron (MLP, Probabilistic Neural network (PNN and Radial basis function network (RBF, were used to classify the six bacteria classes. Results A [6 × 1] SOM network gave 96% accuracy for bacteria classification which was best accuracy. A comparative evaluation of the classifiers was conducted for this application. The best results suggest that we are able to predict six classes of bacteria with up to 98% accuracy with the application of the RBF network. Conclusion This type of bacteria data analysis and feature extraction is very difficult. But we can conclude that this combined use of three nonlinear methods can solve the feature extraction problem with very complex data and enhance the performance of Cyranose 320.

  8. Filamentous bacteria transport electrons over centimetre distances

    DEFF Research Database (Denmark)

    Pfeffer, Christian; Larsen, Steffen; Song, Jie

    2012-01-01

    across centimetre-wide zones. Here we present evidence that the native conductors are long, filamentous bacteria. They abounded in sediment zones with electric currents and along their length they contained strings with distinct properties in accordance with a function as electron transporters. Living...

  9. Spoiled child syndrome.

    Science.gov (United States)

    McIntosh, B J

    1989-01-01

    People often speak of children as being "spoiled" and many parents worry about the possibility of spoiling their infants and children. Many pediatricians, however, are uncomfortable with this term because it is a poorly defined and derogatory expression. Some would even deny that infants and children can be spoiled. Avoiding the use of the expression spoiled can create difficulties in communicating with parents concerned about their children's behavior. In this article, the spoiled child syndrome will be defined and those patterns of behavior that characterize it will be distinguished from other patterns of difficult behavior which may be confused with it. The spoiled child syndrome is characterized by excessive self-centered and immature behavior, resulting from the failure of parents to enforce consistent, age-appropriate limits. Many of the problem behaviors that cause parental concern are unrelated to spoiling as properly understood. Such behaviors are often age-related normal behaviors, reactions to family stresses, or patterns of behavior determined by factors inherent in the child. Pediatricians can provide counseling and reassurance for such behaviors and, by helping parents understand the etiology of true spoiling, can encourage the use of behavior modification techniques for its prevention and treatment.

  10. Spoils of Truce

    DEFF Research Database (Denmark)

    Haugbølle, Sune

    2014-01-01

    Review of Spoils of Truce. Corruption and stat building in Postwar Lebanon Reinoud Leenders Ithaca, NY, Cornell University Press, 2012, ISBN 978-0-8014-5100-3......Review of Spoils of Truce. Corruption and stat building in Postwar Lebanon Reinoud Leenders Ithaca, NY, Cornell University Press, 2012, ISBN 978-0-8014-5100-3...

  11. Beer-spoiling Ability of Lactic Acid Bacteria and its Relation with Genes horA, horC a hitA

    Czech Academy of Sciences Publication Activity Database

    Matoulková, D.; Kubizniaková, P.; Sigler, Karel

    2012-01-01

    Roč. 58, 11-12 (2012), s. 336-342 ISSN 0023-5830 R&D Projects: GA MŠk 1M0570 Institutional support: RVO:61388971 Keywords : beer spoilage * lactic acid bacteria Subject RIV: EE - Microbiology, Virology

  12. Visualizing aquatic bacteria by light and transmission electron microscopy.

    Science.gov (United States)

    Silva, Thiago P; Noyma, Natália P; Duque, Thabata L A; Gamalier, Juliana P; Vidal, Luciana O; Lobão, Lúcia M; Chiarini-Garcia, Hélio; Roland, Fábio; Melo, Rossana C N

    2014-01-01

    The understanding of the functional role of aquatic bacteria in microbial food webs is largely dependent on methods applied to the direct visualization and enumeration of these organisms. While the ultrastructure of aquatic bacteria is still poorly known, routine observation of aquatic bacteria by light microscopy requires staining with fluorochromes, followed by filtration and direct counting on filter surfaces. Here, we used a new strategy to visualize and enumerate aquatic bacteria by light microscopy. By spinning water samples from varied tropical ecosystems in a cytocentrifuge, we found that bacteria firmly adhere to regular slides, can be stained by fluorochoromes with no background formation and fast enumerated. Significant correlations were found between the cytocentrifugation and filter-based methods. Moreover, preparations through cytocentrifugation were more adequate for bacterial viability evaluation than filter-based preparations. Transmission electron microscopic analyses revealed a morphological diversity of bacteria with different internal and external structures, such as large variation in the cell envelope and capsule thickness, and presence or not of thylakoid membranes. Our results demonstrate that aquatic bacteria represent an ultrastructurally diverse population and open avenues for easy handling/quantification and better visualization of bacteria by light microscopy without the need of filter membranes.

  13. Thermophilic spore-forming bacteria isolated from spoiled canned food and their heat resistance. Results of a French ten-year survey.

    Science.gov (United States)

    André, S; Zuber, F; Remize, F

    2013-07-15

    Thermal processing of Low Acid Canned Foods (LACF), which are safe and shelf-stable at ambient temperature for several years, results in heat inactivation of all vegetative microorganisms and the partial or total inactivation of spores. Good Manufacturing Hygienic Practices include stability tests for managing the pathogen risk related to surviving mesophilic bacterial spores. LACF are also often submitted to additional incubation conditions, typically 55 °C for 7 days, to monitor spoilage by thermophiles. In this study we identified the bacterial species responsible for non-stability after prolonged at 55 °C of incubation of LACF from 455 samples collected from 122 French canneries over 10 years. Bacteria were identified by microsequencing or a recent developed tool for group-specific PCR detection (SporeTraQ™). A single species was identified for 93% of examined samples. Three genera were responsible for more than 80% of all non-stability cases: mostly Moorella (36%) and Geobacillus (35%), and less frequently Thermoanaerobacterium (10%). The other most frequent bacterial genera identified were Bacillus, Thermoanaerobacter, Caldanaerobius, Anoxybacillus, Paenibacillus and Clostridium. Species frequency was dependent on food category, i.e. vegetables, ready-made meals containing meat, seafood or other recipes, products containing fatty duck, and related to the intensity of the thermal treatment applied in these food categories. The spore heat resistance parameters (D or δ and z values) from 36 strains isolated in this study were determined. Taken together, our results single out the species most suitable for use as indicators for thermal process settings. This extensively-documented survey of the species that cause non-stability at 55 °C in LACF will help canneries to improve the management of microbial contamination. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Electron microscopic examination of uncultured soil-dwelling bacteria.

    Science.gov (United States)

    Amako, Kazunobu; Takade, Akemi; Taniai, Hiroaki; Yoshida, Shin-ichi

    2008-05-01

    Bacteria living in soil collected from a rice paddy in Fukuoka, Japan, were examined by electron microscopy using a freeze-substitution fixation method. Most of the observed bacteria could be categorized, based on the structure of the cell envelope and overall morphology, into one of five groups: (i) bacterial spore; (ii) Gram-positive type; (iii) Gram-negative type; (iv) Mycobacterium like; and (v) Archaea like. However, a few of the bacteria could not be readily categorized into one of these groups because they had unique cell wall structures, basically resembling those of Gram-negative bacteria, but with the layer corresponding to the peptidoglycan layer in Gram-negative bacteria being extremely thick, like that of the cortex of a bacterial spore. The characteristic morphological features found in many of these uncultured, soil-dwelling cells were the nucleoid being in a condensed state and the cytoplasm being shrunken. We were able to produce similar morphologies in vitro using a Salmonella sp. by culturing under low-temperature, low-nutrient conditions, similar to those found in some natural environments. These unusual morphologies are therefore hypothesized to be characteristic of bacteria in resting or dormant stages.

  15. Placement of acid spoil materials

    Energy Technology Data Exchange (ETDEWEB)

    Pionke, H B; Rogowski, A S

    1982-06-01

    Potentially there are several chemical and hydrologic problems associated with placement of acid spoil materials. The rationale for a deep placement well below the soil surface, and preferably below a water table, is to prevent or minimize oxidation of pyrite to sulfuric acid and associated salts by reducing the supply of oxygen. If, however, substantial sulfuric acid or associated salts are already contained within the spoil because of present or previous mining, handling and reclamation operations (or if large supplies of indigenous salts exist, placement below a water table) may actually increase the rate of acid and salt leaching. Specific placement of acid- and salt-containing spoil should be aimed at preventing contact with percolating water or rising water tables. We recommend placement based on chemical and physical spoil properties that may affect water percolation O/sub 2/ diffusion rates in the profile. Both the deeper placement of acid spoil and coarser particle size can substantially reduce the amount of acid drainage. Placement above the water table with emphasis on percolate control may be better for high sulfate spoils, while placement below the non-fluctuating water table may be better for pyritic spoils.

  16. Non-thermal plasma mills bacteria: Scanning electron microscopy observations

    International Nuclear Information System (INIS)

    Lunov, O.; Churpita, O.; Zablotskii, V.; Jäger, A.; Dejneka, A.; Deyneka, I. G.; Meshkovskii, I. K.; Syková, E.; Kubinová, Š.

    2015-01-01

    Non-thermal plasmas hold great promise for a variety of biomedical applications. To ensure safe clinical application of plasma, a rigorous analysis of plasma-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal plasma remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric plasma on Gram-positive and Gram-negative bacteria. Using scanning electron microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium plasma. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin–stained rat skin sections from plasma–treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal plasma irradiation. Our findings disclose how helium plasma destroys bacteria and demonstrates the safe use of plasma treatment for MSCs and skin cells, highlighting the favorability of plasma applications for chronic wound therapy

  17. In Situ Electron Microscopy of Lactomicroselenium Particles in Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Gabor Nagy

    2016-06-01

    Full Text Available Electron microscopy was used to test whether or not (a in statu nascendi synthesized, and in situ measured, nanoparticle size does not differ significantly from the size of nanoparticles after their purification; and (b the generation of selenium is detrimental to the bacterial strains that produce them. Elemental nano-sized selenium produced by probiotic latic acid bacteria was used as a lactomicroselenium (lactomicroSel inhibitor of cell growth in the presence of lactomicroSel, and was followed by time-lapse microscopy. The size of lactomicroSel produced by probiotic bacteria was measured in situ and after isolation and purification. For these measurements the TESLA BS 540 transmission electron microscope was converted from analog (aTEM to digital processing (dTEM, and further to remote-access internet electron microscopy (iTEM. Lactobacillus acidophilus produced fewer, but larger, lactomicroSel nanoparticles (200–350 nm than Lactobacillus casei (L. casei, which generated many, smaller lactomicroSel particles (85–200 nm and grains as a cloudy, less electrodense material. Streptococcus thermophilus cells generated selenoparticles (60–280 nm in a suicidic manner. The size determined in situ in lactic acid bacteria was significantly lower than those measured by scanning electron microscopy after the isolation of lactomicroSel particles obtained from lactobacilli (100–500 nm, but higher relative to those isolated from Streptococcus thermopilus (50–100 nm. These differences indicate that smaller lactomicroSel particles could be more toxic to the producing bacteria themselves and discrepancies in size could have implications with respect to the applications of selenium nanoparticles as prebiotics.

  18. Intercellular wiring enables electron transfer between methanotrophic archaea and bacteria.

    Science.gov (United States)

    Wegener, Gunter; Krukenberg, Viola; Riedel, Dietmar; Tegetmeyer, Halina E; Boetius, Antje

    2015-10-22

    The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. In marine sediments, AOM is performed by dual-species consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) inhabiting the methane-sulfate transition zone. The biochemical pathways and biological adaptations enabling this globally relevant process are not fully understood. Here we study the syntrophic interaction in thermophilic AOM (TAOM) between ANME-1 archaea and their consortium partner SRB HotSeep-1 (ref. 6) at 60 °C to test the hypothesis of a direct interspecies exchange of electrons. The activity of TAOM consortia was compared to the first ANME-free culture of an AOM partner bacterium that grows using hydrogen as the sole electron donor. The thermophilic ANME-1 do not produce sufficient hydrogen to sustain the observed growth of the HotSeep-1 partner. Enhancing the growth of the HotSeep-1 partner by hydrogen addition represses methane oxidation and the metabolic activity of ANME-1. Further supporting the hypothesis of direct electron transfer between the partners, we observe that under TAOM conditions, both ANME and the HotSeep-1 bacteria overexpress genes for extracellular cytochrome production and form cell-to-cell connections that resemble the nanowire structures responsible for interspecies electron transfer between syntrophic consortia of Geobacter. HotSeep-1 highly expresses genes for pili production only during consortial growth using methane, and the nanowire-like structures are absent in HotSeep-1 cells isolated with hydrogen. These observations suggest that direct electron transfer is a principal mechanism in TAOM, which may also explain the enigmatic functioning and specificity of other methanotrophic ANME-SRB consortia.

  19. Useful materials from colliery spoil

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J

    1975-08-01

    This article is based on a paper presented by the author at a recent symposium on ''The technology of reclamation.'' He discusses the research that is being carried out at the N.C.B.'s Coal Research Establishment into ways of utilizing colliery spoil: unburnt spoil may be used in road construction as fill material or as cement-stabilized sub-bases; the heat-treated spoil can be used as lightweight aggregate in concrete blocks or as dense aggregate for non-skid roadstone. Information is also given about a project to examine the drying of washery tailings in a fluidized-bed combustion system: the material remaining in the bed is immediately usable as a lightweight aggregate, and the fine material blown from the bed and collected in cyclones might be used in the manufacture of cheap artifacts.

  20. Investigation on the spoiling of meat using PTR-MS

    International Nuclear Information System (INIS)

    Mayr, D.; Maerk, T.D.; Margesin, R.; Schinner, F.

    2002-01-01

    The spoiling of meat was investigated. Beef (pork) were wrapped into different kinds of packages (air and vacuum) and stored at 4 o C for 10 (13) days. The emitted volatile organic compounds (VOCs) in the course of time were measured and a large increase in these emissions after a few days of storage was found. Also a large difference in the spoiling behavior between vacuum- and air- packed meat was observed. The measurements were performed using a proton-transfer-reaction-mass spectrometer(PTR-MS) system, it allows on-line monitoring of volatile organic compounds (VOCs) concentrations. Ethylacetate, methylpropionate, and propylformate were detected as typical spoiling compounds in pork samples. After 3.5 days the concentrations started to exponentially increase, but after 6 days remained more or less unchanged. This VOCs behaviour corresponds to a typical bacterial growth curve. Therefore, it was concluded that bacteria produce these components. In a second measurements set, the VOCs emitted by beef under aerobic (normal packed) and anaerobic (vacuum packed) conditions were compared. In the case of normal air-packed beef, the above mentioned spoiling compounds strongly increased with the time, while with the vacuum-packed beef a strong increase of ethanol was detected. This method as a replacement of the bacteriological examinations of meat spoilage is proposed. (nevyjel)

  1. Heme and menaquinone induced electron transport in lactic acid bacteria

    OpenAIRE

    Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

    2009-01-01

    Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacill...

  2. Heme and menaquinone induced electron transport in lactic acid bacteria

    NARCIS (Netherlands)

    Brooijmans, R.J.W.; Smit, B.; Santos, dos F.; Riel, van J.; Vos, de W.M.; Hugenholtz, J.

    2009-01-01

    ABSTRACT: BACKGROUND: For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait.

  3. Reclamation of opencut spoil piles

    Energy Technology Data Exchange (ETDEWEB)

    1976-07-01

    A successful reclamation program requires definite physical/engineering guidelines, a specific time commitment and to be fully integrated in the mining operation enabling most efficient use of available resources. This statement should be immediately qualified by saying that there must be enough flexibility to allow for varying mine layouts, plans and conditions. Mine conditions include physical and chemical spoil properties, climatic conditions and local topographic effects. Whilst reclamation is the responsibility of individual mine managers, the author undertakes a co-ordinating function amongst mine environmental officers to ensure that experience gained is recorded. Exchange of information between mines is maintained and there is a minimum duplication of effort.

  4. Hydroseeding on anthracite coal-mine spoils

    Science.gov (United States)

    Miroslaw M. Czapowskyj; Ross Writer

    1970-01-01

    A study was made of the performance of selected species of legumes, grasses, and trees hydroseeded on anthracite coal-mine spoils in a slurry of lime, fertilizer, and mulch. Hydroseeding failed on coal-breaker refuse, but was partially successful on strip-mine spoils.

  5. Investigations of the effect of electron-beam irradiation on bacteria in sewage sludge

    International Nuclear Information System (INIS)

    Osterstock, G.

    1976-01-01

    The effect of electron beams on bacteria was investigated in 2 experimental facilities. A 400 kV electron accelerator was used to irradiate sludge quantities of 10 l and 180 l. The total bacterial count, the number of coliform bacteria and, in injected sludge, the relative bacteria density of salmonella were investigated. A dose of 0.5 to 0.75 Mrad was required to reduce coliform bacteria to below the detectable level in 0.1 ml. With a dose of 1.5 Mrad salmonella were reduced by 6 orders of magnitude on the average. In addition, the dependence of the reduction in bacteria on the dose rate as well as on mixing of the irradiated material was investigated. Substantial reproduction of bacteria in digested sludge was found in all cases after the irradiation. (orig./MG) [de

  6. Investigations of the effect of electron-beam irradiation on bacteria in sewage sludge

    International Nuclear Information System (INIS)

    Osterstock, G.

    1976-01-01

    The effect of electron beams on bacteria was investigated in 2 experimental facilities. A 400 kV electron accelerator was used to irradiate sludge quantities of 10 l and 180 l. The total bacterial count, number of coliform bacteria and, in injected sludge, the relative bacteria density of salmonella were investigated. A dose of 0.5 to 0.75 Mrad was required to reduce coliform bacteria to below the detectable level in 0.1 ml. With a dose of 1.5 Mrad salmonella were reduced by 6 orders of magnitude on the average. In addition, the dependence of the reduction in bacteria on the dose rate as well as on mixing of the irradiation material was investigated. Substantial reproduction of bacteria in digested sludge was found in all cases after the irradiation. (author)

  7. Bioleaching of metals from electronic scrap by moderately thermophilic acidophilic bacteria

    NARCIS (Netherlands)

    Ilyas, Sadia; Anwar, Munir A.; Niazi, Shahida B.; Ghauri, M. Afzal

    The present work was aimed at studying the bioleachability of metals from electronic scrap by the selected moderately thermophilic strains of acidophilic chemolithotrophic and acidophilic heterotrophic bacteria. These included Sulfobacillus thermosulfidooxidans and an unidentified acidophilic

  8. Heme and menaquinone induced electron transport in lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Santos Filipe

    2009-05-01

    Full Text Available Abstract Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. Conclusion We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

  9. Heme and menaquinone induced electron transport in lactic acid bacteria.

    Science.gov (United States)

    Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

    2009-05-29

    For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

  10. Electron uptake by iron-oxidizing phototrophic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Bose, A; Gardel, EJ; Vidoudez, C; Parra, EA; Girguis, PR

    2014-02-26

    Oxidation-reduction reactions underlie energy generation in nearly all life forms. Although most organisms use soluble oxidants and reductants, some microbes can access solid-phase materials as electron-acceptors or -donors via extracellular electron transfer. Many studies have focused on the reduction of solid-phase oxidants. Far less is known about electron uptake via microbial extracellular electron transfer, and almost nothing is known about the associated mechanisms. Here we show that the iron-oxidizing photoautotroph Rhodopseudomonas palustris TIE-1 accepts electrons from a poised electrode, with carbon dioxide as the sole carbon source/electron acceptor. Both electron uptake and ruBisCo form I expression are stimulated by light. Electron uptake also occurs in the dark, uncoupled from photosynthesis. Notably, the pioABC operon, which encodes a protein system essential for photoautotrophic growth by ferrous iron oxidation, influences electron uptake. These data reveal a previously unknown metabolic versatility of photoferrotrophs to use extracellular electron transfer for electron uptake.

  11. The challenge of non-invasive cognitive physiology of the human brain: how to negotiate the irrelevant background noise without spoiling the recorded data through electronic averaging.

    Science.gov (United States)

    Tomberg, C; Desmedt, J E

    1999-07-29

    Brain mechanisms involved in selective attention in humans can be studied by measures of regional blood flow and metabolism (by positron emission tomography) which help identify the various locations with enhanced activities over a period of time of seconds. The physiological measures provided by scalp-recorded brain electrical potentials have a better resolution (milliseconds) and can reveal the actual sequences of distinct neural events and their precise timing. We studied selective attention to sensory inputs from fingers because the brain somatic representations are deployed over the brain convexity under the scalp thereby making it possible to assess distinct stages of cortical processing and representation through their characteristic scalp topographies. In the electrical response to a finger input attended by the subject, the well-known P300 manifests a widespread inhibitory mechanism which is released after a target stimulus has been identified. P300 is preceded by distinct cognitive electrogeneses such as P40, P100 and N140 which can be differentiated from the control (obligatory) profile by superimposition or electronic subtraction. The first cortical response N20 is stable across conditions, suggesting that the first afferent thalamocortical volley is not affected by selective attention. At the next stage of modality-specific cortex in which the sensory features are processed and represented, responses were enhanced (cognitive P40) only a very few milliseconds after arrival of the afferent volley at the cortex, thus documenting a remarkable precocity of attention gain control in the somatic modality. The physiology of selective attention also provides useful cues in relation to non-target inputs which the subject must differentiate in order to perform the task. When having to tell fingers apart, the brain strategy for non-target fingers is not to inhibit or filter them out, but rather to submit their input to several processing operations that are

  12. Non-thermal plasma mills bacteria: scanning electron microscopy observations

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg; Churpita, Olexandr; Zablotskyy, Vitaliy A.; Deyneka, I.G.; Meshkovskii, I.K.; Jäger, Aleš; Syková, Eva; Kubinová, Šárka; Dejneka, Alexandr

    2015-01-01

    Roč. 106, č. 5 (2015), "053703-1"-"053703-5" ISSN 0003-6951 R&D Projects: GA MŠk(CZ) LM2011029; GA MŠk(CZ) LM2011026; GA MŠk LO1309 Grant - others:AV ČR(CZ) M100101219; SAFMAT(XE) CZ.2.16/3.1.00/22132 Institutional support: RVO:68378271 ; RVO:68378041 Keywords : non-thermal plasma * plasma medicine * bacteria * cells Subject RIV: BO - Biophysics Impact factor: 3.142, year: 2015

  13. Electronic Nose Characterization of the Quality Parameters of Freeze-Dried Bacteria

    Science.gov (United States)

    Capuano, R.; Santonico, M.; Martinelli, E.; Paolesse, R.; Passot, S.; Fonseca, F.; Cenard, S.; Trelea, C.; Di Natale, C.

    2011-09-01

    Freeze-drying is the method of choice for preserving heat sensitive biological products such as microorganisms. The development of a fast analytical method for evaluating the properties of the dehydrated bacteria is then necessary for a proper utilization of the product in several food processes. In this paper, dried bacteria headspace is analyzed by a GC-MS and an electronic nose. Results indicate that headspace contains enough information to assess the products quality.

  14. Enumeration and biomass estimation of planktonic bacteria and viruses by transmission electron microscopy

    International Nuclear Information System (INIS)

    Borsheim, K.Y.; Bratbak, G.; Heldal, M.

    1990-01-01

    Bacteria and virus particles were harvested from water samples by ultracentrifugation directly onto Formvar-coated electron microscopy grids and counted in a transmission electron microscope. With this technique, we have counted and sized bacteria and viruses in marine water samples and during laboratory incubations. By X-ray microanalysis, we could determine the elemental composition and dry-matter content of individual bacteria. The dry weight/volume ratio for the bacteria was 600 fg of dry weight microns-3. The potassium content of the bacteria was normal compared with previous estimates from other bacterial assemblages; thus, this harvesting procedure did not disrupt the bacterial cells. Virus particles were, by an order of magnitude, more abundant than bacteria in marine coastal waters. During the first 5 to 7 days of incubation, the total number of viruses increased exponentially at a rate of 0.4 day-1 and thereafter declined. The high proliferation rate suggests that viral parasitism may affect mortality of bacteria in aquatic environments

  15. Long-distance electron transport in individual, living cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper T; Boschker, Henricus T S; Larsen, Steffen

    2018-01-01

    redox potential was detected, which immediately broke down upon removal of oxygen or laser cutting of the filaments. Without access to oxygen, a rapid shift toward more reduced cytochromes was observed, as electrons were no longer drained from the filament but accumulated in the cellular cytochromes...

  16. Electron transport chains in organohalide-respiring bacteria and bioremediation implications.

    Science.gov (United States)

    Wang, Shanquan; Qiu, Lan; Liu, Xiaowei; Xu, Guofang; Siegert, Michael; Lu, Qihong; Juneau, Philippe; Yu, Ling; Liang, Dawei; He, Zhili; Qiu, Rongliang

    2018-04-06

    In situ remediation employing organohalide-respiring bacteria represents a promising solution for cleanup of persistent organohalide pollutants. The organohalide-respiring bacteria conserve energy by utilizing H 2 or organic compounds as electron donors and organohalides as electron acceptors. Reductive dehalogenase (RDase), a terminal reductase of the electron transport chain in organohalide-respiring bacteria, is the key enzyme that catalyzes halogen removal. Accumulating experimental evidence thus far suggests that there are distinct models for respiratory electron transfer in organohalide-respirers of different lineages, e.g., Dehalococcoides, Dehalobacter, Desulfitobacterium and Sulfurospirillum. In this review, to connect the knowledge in organohalide-respiratory electron transport chains to bioremediation applications, we first comprehensively review molecular components and their organization, together with energetics of the organohalide-respiratory electron transport chains, as well as recent elucidation of intramolecular electron shuttling and halogen elimination mechanisms of RDases. We then highlight the implications of organohalide-respiratory electron transport chains in stimulated bioremediation. In addition, major challenges and further developments toward understanding the organohalide-respiratory electron transport chains and their bioremediation applications are identified and discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Bacteria Associated with Fresh Tilapia Fish (Oreochromis niloticus ...

    African Journals Online (AJOL)

    acer

    Keywords: Bacteria, Tilapia fish and Sokoto central market. INTRODUCTION ... The bacteria are transmitted by fish that have made contact ... with which a product spoils is also related to the .... Base on the percentage frequency of occurance ,.

  18. Classification of human pathogen bacteria for early screening using electronic nose

    Science.gov (United States)

    Zulkifli, Syahida Amani; Mohamad, Che Wan Syarifah Robiah; Abdullah, Abu Hassan

    2017-10-01

    This paper present human pathogen bacteria for early screening using electronic nose. Electronic nose (E-nose) known as gas sensor array is a device that analyze the odor measurement give the fast response and less time consuming for clinical diagnosis. Many bacterial pathogens could lead to life threatening infections. Accurate and rapid diagnosis is crucial for the successful management of these infections disease. The conventional method need more time to detect the growth of bacterial. Alternatively, the bacteria are Pseudomonas aeruginosa and Shigella cultured on different media agar can be detected and classifies according to the volatile compound in shorter time using electronic nose (E-nose). Then, the data from electronic nose (E-nose) is processed using statistical method which is principal component analysis (PCA). The study shows the capability of electronic nose (E-nose) for early screening for bacterial infection in human stomach.

  19. Bioleaching of electronic waste using bacteria isolated from the marine sponge Hymeniacidon heliophila (Porifera).

    Science.gov (United States)

    Rozas, Enrique E; Mendes, Maria A; Nascimento, Claudio A O; Espinosa, Denise C R; Oliveira, Renato; Oliveira, Guilherme; Custodio, Marcio R

    2017-05-05

    The bacteria isolated from Hymeniacidon heliophila sponge cells showed bioleaching activity. The most active strain, Hyhel-1, identified as Bacillus sp., was selected for bioleaching tests under two different temperatures, 30°C and 40°C, showing rod-shaped cells and filamentous growth, respectively. At 30°C, the bacteria secreted substances which linked to the leached copper, and at 40°C metallic nanoparticles were produced inside the cells. In addition, infrared analysis detected COOH groups and linear peptides in the tested bacteria at both temperatures. The Hyhel-1 strain in presence of electronic waste (e-waste) induced the formation of crust, which could be observed due to bacteria growing on the e-waste fragment. SEM-EDS measurements showed that the bacterial net surface was composed mostly of iron (16.1% w/w), while a higher concentration of copper was observed in the supernatant (1.7% w/w) and in the precipitated (49.8% w/w). The substances linked to copper in the supernatant were sequenced by MALDI-TOF-ms/ms and identified as macrocyclic surfactin-like peptides, similar to the basic sequence of Iturin, a lipopeptide from Bacillus subtilis. Finally, the results showed that Hyhel-1 is a bioleaching bacteria and cooper nanoparticles producer and that this bacteria could be used as a copper recovery tool from electronic waste. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The biological costs of not reclaiming bentonite mine spoils

    Science.gov (United States)

    Carolyn Hull Sieg; Daniel W. Uresk; Richard M. Hansen

    1982-01-01

    Bentonite clay has been mined in the northern Great Plains for more than 80 years. Until the late 1960's, mine spoil materials were left in steep piles and no effort was made to restore biological productivity to these disturbed sites. As a result, unreclaimed spoils are barren and eroded. The biological costs of not reclaiming these spoils are examined in this...

  1. Race, Commitment to Deviance, and Spoiled Identity

    Science.gov (United States)

    Harris, Anthony R.

    1976-01-01

    Data generated by 234 young black and white inmates in 1971 challenge the assumption that spoiled identity is a necessary, socially invariant outcome of deviant commitment and self-definition. For blacks, the relationship between criminal self-typing and stability and esteem is negative but inconsequential; for whites, the relationship is negative…

  2. A Spectral Emissivity Library of Spoil Substrates

    Czech Academy of Sciences Publication Activity Database

    Pivovarník, Marek; Pikl, Miroslav; Frouz, J.; Zemek, František; Kopačková, V.; Notesco, G.; Ben Dor, E.

    2016-01-01

    Roč. 1, č. 2 (2016) E-ISSN 2306-5729 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : post-mining sites * spectral emissivity * spectral library * spoil substrates Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

  3. Sensitivity of spoiling and pathogen food-related bacteria to Origanum vulgare L. (Lamiaceae essential oil Sensibilidade de bactérias deteriorantes e patogênicas de interesse em alimentos ao óleo essencial de Origanum vulgare L. (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Evandro Leite de Souza

    2006-12-01

    Full Text Available Origanum vulgare L. (oregano, Lamiaceae, has been known as plant specie with prominent biological properties for a long time. This study aimed to evaluate the antibacterial activity of Origanum vulgare essential oil on various Gram-positive and Gram-negative spoiling and/or pathogen food-related bacteria, as well as to observe its antimicrobial effectiveness in a food conservation micromodel. The results showed a strong antibacterial activity of the assayed essential oil noted by large growth inhibition zones (30-37 mm. MIC values were between 20-40 µL/mL for the most bacteria strains. Essential oil was able to cause significant (POriganum vulgare L. (orégano, Lamiaceae, tem sido reconhecida como uma espécie vegetal com destacáveis propriedades biológicas por um longo tempo. Este estudo objetivou avaliar a atividade antibacteriana do óleo essencial de Origanum vulgare L. sobre várias bactérias Gram positivas e Gram negativas deteriorantes e/ou patogênicas de interesse em alimentos, bem como observar sua efetividade antimicrobiana em um micromodelo de conservação de alimentos. Os resultados mostraram uma considerável atividade antibacteriana do óleo essencial ensaiado notada por grandes zonas de inibição do crescimento bacteriano (30-37 mm. Os valores de CIM encontrados oscilaram entre 20-40 µL/mL para a maioria das bactérias. A CIM do óleo essencial causou um significante (P<0.05 efeito inibitório sobre a viabilidade bacteriana, sendo caracterizado uma propriedade bacteriostática após 24 horas de exposição. Ainda, a CIM causou uma diminuição significante (P<0.05 da contagem da flora bacteriana autóctone em carne moída armazenada sob refrigeração. Estes dados suportam a possibilidade do uso do óleo essencial de Origanum vulgare L. como composto antimicrobiano alternativo em sistemas de conservação de alimentos.

  4. Protective-decorative revegetation of spoil banks in the Donbass

    Energy Technology Data Exchange (ETDEWEB)

    Baklanov, V.I.; Podkopaev, A.A.

    1985-05-01

    Spoil bank reclamation in the Donbass is discussed, where there were 1195 spoil banks from underground coal mines in 1984, 80% of which were conic shaped. The average spoil bank was 60 to 80 m high, base surface was 4.2 ha, volume amounted to 1,144,000 mT. Ninety-five spoil banks were situated in cities or towns and were a source of environmental pollution. Reclamation of a spoil bank in the No 6/14 coal mine in the Makeevugol' association is analyzed. Buildup of the spoil bank started in 1930. The spoil bank was 72 m high, its base was 8.05 ha large, slopes were inclined at 25 to 36 degrees, volume of material amounted to 2.2 million mT. From 1973 to 1978 shape of the spoil bank was changed: its height was reduced to 40 m, slope inclination was reduced to 25 degrees. Spontaneous combustion was controlled by changing spoil bank shape. Slopes were divided into a number of terraces. The spoil bank was covered with a 0.3 m thick soil cover suitable for vegetation. Sainfoin (Onobrychis) was sown on leveled zones of the spoil bank and false acacia (Robinia pseudoacacia) was planted on the terraces. Plant growth in the first and second years was satisfactory.

  5. Spoil characteristics and vegetation development of an age series of mine spoils in a dry tropical environment

    Energy Technology Data Exchange (ETDEWEB)

    Jha, A K; Singh, J S [Banaras Hindu University, Varanasi (India). Dept. of Botany

    1991-12-01

    A series of coal mine spoils (5,10,12,16 and 20-yr old) in a dry tropical environment was sampled to assess the changes with time in spoil characteristics, species composition and plant biomass. Coarse fragments ({gt} 2 mm) decreased with age of mine spoil while the proportion of 0.2-0.1 mm particles increased. Total soil N, mineral N, NaHCO{sub 3}-extractable P, and exchangeable K increased with age of mine spoil and these parameters were lower in mine spoils than native forest soil even after 20 years of succession. Exchangeable Na decreased with age of mine spoil and in 20-yr old spoil it was higher than native forest soil. Plant community composition changed with age. Only a few species participated in community formation. Species richness increased with age, while evenness and species diversity declined from 5-yr old to 16-yr old community with an increase in the 20-yr old community. A reverse trend occurred for concentration of dominance. Area-weighted shoot and root biomass of other species increased with the age of the mine spoil while that of Xanthium strumarium patches declined with age. Data collection on spoil features, microbial C, N and P,and shoot and root biomass when subjected to Discriminant Analysis indicated a continued profound effect of age. 10 and 12-yr old mine spoils were closer to each other and 5 and 20-yr old spoils were farthest apart.

  6. Spoil characteristics and vegetation development of an age series of mine spoils in a dry tropical environment

    International Nuclear Information System (INIS)

    Jha, A.K.; Singh, J.S.

    1991-01-01

    A series of coal mine spoils (5,10,12,16 and 20-yr old) in a dry tropical environment was sampled to assess the changes with time in spoil characteristics, species composition and plant biomass. Coarse fragments (> 2 mm) decreased with age of mine spoil while the proportion of 0.2-0.1 mm particles increased. Total soil N, mineral N, NaHCO 3 -extractable P, and exchangeable K increased with age of mine spoil and these parameters were lower in mine spoils than native forest soil even after 20 years of succession. Exchangeable Na decreased with age of mine spoil and in 20-yr old spoil it was higher than native forest soil. Plant community composition changed with age. Only a few species participated in community formation. Species richness increased with age, while evenness and species diversity declined from 5-yr old to 16-yr old community with an increase in the 20-yr old community. A reverse trend occurred for concentration of dominance. Area-weighted shoot and root biomass of other species increased with the age of the mine spoil while that of Xanthium strumarium patches declined with age. Data collection on spoil features, microbial C, N and P,and shoot and root biomass when subjected to Discriminant Analysis indicated a continued profound effect of age. 10 and 12-yr old mine spoils were closer to each other and 5 and 20-yr old spoils were farthest apart

  7. Isolation of acetogenic bacteria that induce biocorrosion by utilizing metallic iron as the sole electron donor.

    Science.gov (United States)

    Kato, Souichiro; Yumoto, Isao; Kamagata, Yoichi

    2015-01-01

    Corrosion of iron occurring under anoxic conditions, which is termed microbiologically influenced corrosion (MIC) or biocorrosion, is mostly caused by microbial activities. Microbial activity that enhances corrosion via uptake of electrons from metallic iron [Fe(0)] has been regarded as one of the major causative factors. In addition to sulfate-reducing bacteria and methanogenic archaea in marine environments, acetogenic bacteria in freshwater environments have recently been suggested to cause MIC under anoxic conditions. However, no microorganisms that perform acetogenesis-dependent MIC have been isolated or had their MIC-inducing mechanisms characterized. Here, we enriched and isolated acetogenic bacteria that induce iron corrosion by utilizing Fe(0) as the sole electron donor under freshwater, sulfate-free, and anoxic conditions. The enriched communities produced significantly larger amounts of Fe(II) than the abiotic controls and produced acetate coupled with Fe(0) oxidation prior to CH4 production. Microbial community analysis revealed that Sporomusa sp. and Desulfovibrio sp. dominated in the enrichments. Strain GT1, which is closely related to the acetogen Sporomusa sphaeroides, was eventually isolated from the enrichment. Strain GT1 grew acetogenetically with Fe(0) as the sole electron donor and enhanced iron corrosion, which is the first demonstration of MIC mediated by a pure culture of an acetogen. Other well-known acetogenic bacteria, including Sporomusa ovata and Acetobacterium spp., did not grow well on Fe(0). These results indicate that very few species of acetogens have specific mechanisms to efficiently utilize cathodic electrons derived from Fe(0) oxidation and induce iron corrosion. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Spoil dump design and rehabilitation management practices (Australia)

    International Nuclear Information System (INIS)

    Goh, E.K.H.; Aspinall, T.O.; Kuszmaul, J.S.

    1998-01-01

    The environmental impact of mining and evolving environmental legislation has been receiving increased attention worldwide in the last two decades. The potential impacts associated with unstable spoil dumps from mine operations is the focus of concern both by the mining industry, environmental legislative agencies and members of the public. Engineered slopes of mine spoils may be stable at the end of construction, but they can deteriorate over time. There is thus the need to increase the base of knowledge on the existing practices of spoil dump design and rehabilitation. Information concluded from the analysis of the industrial survey carried out on Australian spoil dump management practices at coal, gold and ore mines are presented in this paper. The questionnaire asked for details of soil type of spoils, and factors influencing the design of spoil dumps (climate, rate of erosion, height of dumps, slope gradient and length, overburden handling equipment, soil characteristics, legislation and wastes). 10 refs., 5 figs., 5 tabs

  9. Electron beam fabrication of a microfluidic device for studying submicron-scale bacteria

    Science.gov (United States)

    2013-01-01

    Background Controlled restriction of cellular movement using microfluidics allows one to study individual cells to gain insight into aspects of their physiology and behaviour. For example, the use of micron-sized growth channels that confine individual Escherichia coli has yielded novel insights into cell growth and death. To extend this approach to other species of bacteria, many of whom have dimensions in the sub-micron range, or to a larger range of growth conditions, a readily-fabricated device containing sub-micron features is required. Results Here we detail the fabrication of a versatile device with growth channels whose widths range from 0.3 μm to 0.8 μm. The device is fabricated using electron beam lithography, which provides excellent control over the shape and size of different growth channels and facilitates the rapid-prototyping of new designs. Features are successfully transferred first into silicon, and subsequently into the polydimethylsiloxane that forms the basis of the working microfluidic device. We demonstrate that the growth of sub-micron scale bacteria such as Lactococcus lactis or Escherichia coli cultured in minimal medium can be followed in such a device over several generations. Conclusions We have presented a detailed protocol based on electron beam fabrication together with specific dry etching procedures for the fabrication of a microfluidic device suited to study submicron-sized bacteria. We have demonstrated that both Gram-positive and Gram-negative bacteria can be successfully loaded and imaged over a number of generations in this device. Similar devices could potentially be used to study other submicron-sized organisms under conditions in which the height and shape of the growth channels are crucial to the experimental design. PMID:23575419

  10. New possibilities for slope stability assessment of spoil banks

    Energy Technology Data Exchange (ETDEWEB)

    Radl, A [Palivovy Kombinat, Vresova (Czechoslovakia)

    1991-03-01

    Discusses problems associated with slope stability of spoil banks consisting of sedimentary rocks from brown coal surface mining. Effects of rock physical properties on slope stability are analyzed: grain size distribution, compression strength, moisture content, angle of internal friction, etc. Mechanism of plastic slope deformation which occurs during a landslide is evaluated. Formulae for calculating slope stability considering stress distribution in a spoil bank (including all the main factors that influence stresses) are derived. Practical use of the gamma-gamma logging and logging schemes used in geodetic surveys of unstable spoil banks in Czechoslovakia (the Vintirov spoil bank in the Sokolov brown coal district) are discussed. 5 refs.

  11. Long-distance electron transfer by cable bacteria in aquifer sediments

    DEFF Research Database (Denmark)

    Müller, Hubert; Bosch, Julian; Griebler, Christian

    2016-01-01

    recycling of sulfate by electron transfer over 1–2-cm distance. Sediments were taken from a hydrocarbon-contaminated aquifer, amended with iron sulfide and saturated with water, leaving the sediment surface exposed to air. Steep geochemical gradients developed in the upper 3 cm, showing a spatial separation...... recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic–anoxic interfaces in aquifer sediments, where they provide a means for the direct...

  12. Hydrologic modeling of reclaimed strip mine spoil

    International Nuclear Information System (INIS)

    Edwards, K.B.; Stoertz, M.W.; Turney, D.C.

    1998-01-01

    A numerical groundwater flow model (MODFLOW) of a surface coal mine in southeast Ohio was calibrated under steady state conditions to match measured heads by varying hydraulic conductivity (K) and recharge (R). Sensitivity studies indicated that K was not largely dependent on the poorly quantified underclay elevation or on the lake boundary condition. The baseflow recharge was determined to be between 8 and 60 mm/yr (1 to 6% of annual rainfall) and K between 0.004 and 0.01 cm/s for the spoil aquifer

  13. Characterization of intact subcellular bodies in whole bacteria by cryo-electron tomography and spectroscopic imaging.

    Science.gov (United States)

    Comolli, L R; Kundmann, M; Downing, K H

    2006-07-01

    We illustrate the combined use of cryo-electron tomography and spectroscopic difference imaging in the study of subcellular structure and subcellular bodies in whole bacteria. We limited our goal and focus to bodies with a distinct elemental composition that was in a sufficiently high concentration to provide the necessary signal-to-noise level at the relatively large sample thicknesses of the intact cell. This combination proved very powerful, as demonstrated by the identification of a phosphorus-rich body in Caulobacter crescentus. We also confirmed the presence of a body rich in carbon, demonstrated that these two types of bodies are readily recognized and distinguished from each other, and provided, for the first time to our knowledge, structural information about them in their intact state. In addition, we also showed the presence of a similar type of phosphorus-rich body in Deinococcus grandis, a member of a completely unrelated bacteria genus. Cryo-electron microscopy and tomography allowed the study of the biogenesis and morphology of these bodies at resolutions better than 10 nm, whereas spectroscopic difference imaging provided a direct identification of their chemical composition.

  14. Effects of gamma ray and electron-beam irradiations on survival of anaerobic and facultatively anaerobic bacteria

    International Nuclear Information System (INIS)

    Miyahara, Michiko; Miyahara, Makoto

    2002-01-01

    An extension of the approval for food irradiation is desired due to the increase in the incidence of food poisoning in the world. One anaerobic (Clostridium perfringens) and four facultatively anaerobic (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis) bacteria irradiated with gamma ray or electron beam (E-beam) were tested in terms of survival on agar under packaging atmosphere. Using pouch pack, effects of two irradiations on survival of anaerobic and facultatively anaerobic bacteria were evaluated comparatively. E-beam irradiation was more effective than gamma ray irradiation in decreasing the lethal dose 10% (D 10 ) value of B. cereus at 4 deg C, slightly more effective in that of E. coli O157, and similarly effective in that of the other three bacteria at 4 deg C. The gamma irradiation of the bacteria without incubation at 4 deg C before irradiation was more effective than that of the bacteria with incubation overnight at 4 deg C before irradiation in decreasing the D10 values of these bacteria (B. cereus, E. coli O157, and L. monocytogenes). Furthermore, ground beef patties inoculated with bacteria were irradiated with 1 kGy by E-beam (5 MeV) at 4 deg C. The inoculated bacteria in the 1-9 mm beef patties were killed by 1 kGy E-beam irradiation and some bacteria in more than 9 mm beef patties were not killed by the irradiation. (author)

  15. Long helical filaments are not seen encircling cells in electron cryotomograms of rod-shaped bacteria

    International Nuclear Information System (INIS)

    Swulius, Matthew T.; Chen, Songye; Jane Ding, H.; Li, Zhuo; Briegel, Ariane; Pilhofer, Martin; Tocheva, Elitza I.; Lybarger, Suzanne R.; Johnson, Tanya L.; Sandkvist, Maria; Jensen, Grant J.

    2011-01-01

    Highlights: → No long helical filaments are seen near or along rod-shaped bacterial inner membranes by electron cryo-tomography. → Electron cryo-tomography has the resolution to detect single filaments in vivo. -- Abstract: How rod-shaped bacteria form and maintain their shape is an important question in bacterial cell biology. Results from fluorescent light microscopy have led many to believe that the actin homolog MreB and a number of other proteins form long helical filaments along the inner membrane of the cell. Here we show using electron cryotomography of six different rod-shaped bacterial species, at macromolecular resolution, that no long (>80 nm) helical filaments exist near or along either surface of the inner membrane. We also use correlated cryo-fluorescent light microscopy (cryo-fLM) and electron cryo-tomography (ECT) to identify cytoplasmic bundles of MreB, showing that MreB filaments are detectable by ECT. In light of these results, the structure and function of MreB must be reconsidered: instead of acting as a large, rigid scaffold that localizes cell-wall synthetic machinery, moving MreB complexes may apply tension to growing peptidoglycan strands to ensure their orderly, linear insertion.

  16. Asfordby spoiled - remote disposal of spoil - the case of Asfordby mine in Leicestershire

    Energy Technology Data Exchange (ETDEWEB)

    Rose, D

    1988-03-01

    The Asfordby Mine Project in Leicestershire, UK is scheduled for completion in 1993/4 and should produce 3 mt of coal pa. An estimated 650 000 tpa of spoil would be generated, 10% of which could be used for backfilling elsewhere in the area. The creation of spoil heaps on site was rejected by the County Council on environmental and agricultural grounds, and remote disposal was investigated by a Working Party. Four remote sites were identified, having disposal costs varying from 3.82 to 11.34 UKL per tonne (compared with 2.10 UKL on site). A pilot remote disposal scheme involving two old clay pits was explored, but the costs were found to outweigh the other advantages and so the idea has been dropped. Appeals have been made to the Department of the Environment to reconsider the advantages of such an innovative approach and to seek funding for it from the site operator and the EEC.

  17. Recognizing critical mine spoil health characteristics to design ...

    Science.gov (United States)

    Biochar can be used as an amendment to remediate metal-contaminated mine spoils for improved site phytostabilization. For successful phytostabilization to occur, biochar amendments must improve mine spoil health with respect to plant rooting plus uptake of water and nutrients. An inappropriate biochar may negatively impact plant growth conditions resulting in poor plant establishment and growth. Matching the appropriate biochar for each mine site requires reconnaissance of spoil chemical and physical conditions and then identifying which properties need rectified to promote plant growth. A rectification hierarchy needs to be established with the primary limiting factor being addressed first, then successive limitations addressed simultaneously or thereafter. We posit that spoils at each site will have a unique chemical, physical, and biological signature that will affect plant growth. For example, some spoils may be extremely acidic, possess phytotoxic concentrations of heavy metals, or have physical conditions that limits water storage and root penetration. Quantifying these and other conditions beforehand allows for the production of designer biochar with specific characteristics tailored for specific plant growth deficiencies within each spoil. Additionally, we recommend the use of proximally located, undisturbed soils to establish spoil remediation targets. In our work, we have developed a decision-tree flow-chart that identifies salient chemical,

  18. Long-distance electron transport by cable bacteria in mangrove sediments

    NARCIS (Netherlands)

    Burdorf, L.D.; Hidalgo-Martinez, S.; Cook, P.L.M.C.; Meysman, F.

    2016-01-01

    Cable bacteria are long, filamentoussulphur-oxidizing bacteria that induce long-distanceelectron transport in aquatic sediments. They turnthe seafloor into an electro-active environment, characterizedby currents and electrical fields, and whenpresent, they exert a strong impact on the

  19. Electronic cigarette inhalation alters innate immunity and airway cytokines while increasing the virulence of colonizing bacteria.

    Science.gov (United States)

    Hwang, John H; Lyes, Matthew; Sladewski, Katherine; Enany, Shymaa; McEachern, Elisa; Mathew, Denzil P; Das, Soumita; Moshensky, Alexander; Bapat, Sagar; Pride, David T; Ongkeko, Weg M; Crotty Alexander, Laura E

    2016-06-01

    Electronic (e)-cigarette use is rapidly rising, with 20 % of Americans ages 25-44 now using these drug delivery devices. E-cigarette users expose their airways, cells of host defense, and colonizing bacteria to e-cigarette vapor (EV). Here, we report that exposure of human epithelial cells at the air-liquid interface to fresh EV (vaped from an e-cigarette device) resulted in dose-dependent cell death. After exposure to EV, cells of host defense-epithelial cells, alveolar macrophages, and neutrophils-had reduced antimicrobial activity against Staphylococcus aureus (SA). Mouse inhalation of EV for 1 h daily for 4 weeks led to alterations in inflammatory markers within the airways and elevation of an acute phase reactant in serum. Upon exposure to e-cigarette vapor extract (EVE), airway colonizer SA had increased biofilm formation, adherence and invasion of epithelial cells, resistance to human antimicrobial peptide LL-37, and up-regulation of virulence genes. EVE-exposed SA were more virulent in a mouse model of pneumonia. These data suggest that e-cigarettes may be toxic to airway cells, suppress host defenses, and promote inflammation over time, while also promoting virulence of colonizing bacteria. Acute exposure to e-cigarette vapor (EV) is cytotoxic to airway cells in vitro. Acute exposure to EV decreases macrophage and neutrophil antimicrobial function. Inhalation of EV alters immunomodulating cytokines in the airways of mice. Inhalation of EV leads to increased markers of inflammation in BAL and serum. Staphylococcus aureus become more virulent when exposed to EV.

  20. Dredge spoil disposal off Kavaratti Island, Lakshadweep, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; SanilKumar, V.; Jayakumar, S.

    Maintenance dredging has been carried out along the navigational channel at Kavaratii Island and dredge spoil is disposed in the open sea. This paper describes the movement of sediment plume while dredging and disposal. The study indicates...

  1. Stabilization of dredged spoils for pavement construction in the ...

    African Journals Online (AJOL)

    Natural soils underlying the East-West road are mainly clay and silt of poor quality ... on the dredged soils included particle size distribution, compaction and California Bearing Ratio. Cement stabilization was performed on the dredged spoil.

  2. stabilization of dredged spoils for pavement construction in the niger

    African Journals Online (AJOL)

    Dr. Tse

    Natural soils underlying the East-West road are mainly clay and silt of poor quality ... on the dredged soils included particle size distribution, compaction and California ... KEYWORDS: Stabilization, dredge spoil, pavement, Niger Delta, cement.

  3. Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Liang; Rosso, Kevin M.; Zachara, John M.; Fredrickson, Jim K.

    2012-12-01

    Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), the Mtr (i.e., metal-reducing) pathway exists in all characterized strains of metal-reducing Shewanella. The protein components identified to date for the Mtr pathway of MR-1 include four multi-heme c-type cytochromes (c-Cyts), CymA, MtrA, MtrC and OmcA, and a porin-like, outer membrane protein MtrB. They are strategically positioned along the width of the MR-1 cell envelope to mediate electron transfer from the quinone/quinol pool in the inner-membrane to the Fe(III)-containing minerals external to the bacterial cells. A survey of microbial genomes revealed homologues of the Mtr pathway in other dissimilatory Fe(III)-reducing bacteria, including Aeromonas hydrophila, Ferrimonas balearica and Rhodoferax ferrireducens, and in the Fe(II)-oxidizing bacteria Dechloromonas aromatica RCB, Gallionella capsiferriformans ES-2 and Sideroxydans lithotrophicus ES-1. The widespread distribution of Mtr pathways in Fe(III)-reducing or Fe(II)-oxidizing bacteria emphasizes the importance of this type of extracellular electron transfer pathway in microbial redox transformation of Fe. Their distribution in these two different functional groups of bacteria also emphasizes the bi-directional nature of electron transfer reactions carried out by the Mtr pathways. The characteristics of the Mtr pathways may be shared by other pathways used by microorganisms for exchanging electrons with their extracellular environments.

  4. Diversity and ubiquity of bacteria capable of utilizing humic substances as electron donors for anaerobic respiration.

    Science.gov (United States)

    Coates, John D; Cole, Kimberly A; Chakraborty, Romy; O'Connor, Susan M; Achenbach, Laurie A

    2002-05-01

    Previous studies have demonstrated that reduced humic substances (HS) can be reoxidized by anaerobic bacteria such as Geobacter, Geothrix, and Wolinella species with a suitable electron acceptor; however, little is known of the importance of this metabolism in the environment. Recently we investigated this metabolism in a diversity of environments including marine and aquatic sediments, forest soils, and drainage ditch soils. Most-probable-number enumeration studies were performed using 2,6-anthrahydroquinone disulfonate (AHDS), an analog for reduced HS, as the electron donor with nitrate as the electron acceptor. Anaerobic organisms capable of utilizing reduced HS as an electron donor were found in all environments tested and ranged from a low of 2.31 x 10(1) in aquifer sediments to a high of 9.33 x 10(6) in lake sediments. As part of this study we isolated six novel organisms capable of anaerobic AHDS oxidation. All of the isolates coupled the oxidation of AHDS to the reduction of nitrate with acetate (0.1 mM) as the carbon source. In the absence of cells, no AHDS oxidation was apparent, and in the absence of AHDS, no cell density increase was observed. Generally, nitrate was reduced to N(2). Analysis of the AHDS and its oxidized form, 2,6-anthraquinone disulfonate (AQDS), in the medium during growth revealed that the anthraquinone was not being biodegraded as a carbon source and was simply being oxidized as an energy source. Determination of the AHDS oxidized and nitrate reduced accounted for 109% of the theoretical electron transfer. In addition to AHDS, all of these isolates could also couple the oxidation of reduced humic substances to the reduction of nitrate. No HS oxidation occurred in the absence of cells and in the absence of a suitable electron acceptor, demonstrating that these organisms were capable of utilizing natural HS as an energy source and that AHDS serves as a suitable analog for studying this metabolism. Alternative electron donors included

  5. Reclamation of coal mine spoil dump through integrated biotechnological approach

    International Nuclear Information System (INIS)

    Juwarkar, A.S.; Thawale, P.R.; Mowade, S.; Shrivastava, S.; Deshbhratar, P.B.; Juwarkar, A.

    1994-01-01

    Laboratory and field studies were carried out to restore the fertility and productivity of coal mine spoil using primary clarifier sludge from paper mill effluent treatment plant and use of specialised culture of biofertilizers and mycorrhizal fungi. Plants namely Tectona grandis, Delbergia sissoo, Gmelina arporea, Emblica officinalis and Cassia seamea were grown. Sludge amendment enhanced the survival rate of plants to 80% compared to 20% in unamended spoil. Plants grown on unamended spoil showed stunted growth. Growth of plants increased by 188-484% when sludge was applied at the rate of 100 tonnes per hectare. At 100 tones per hectare sludge amendment, biofertilizer and mycorrhizae treatment there were 83.7 nodules in shishum as against only 4.6 nodules in case of spoil alone. Further root length was 276% and 281% more respectively in case of shishum and teak. Inoculation of plant saplings with respective biofertilizers and mycorrhizae further increased the plant growth by 144-198%. At Durgapur coal mine, 56,000 saplings of Tectona grandis, Gmelina arporea, Delbergia sissoo, Emblica officinalis, Azadirachta indica, Acacia ariculiformis, Prosopis etc were successfully planted on spoil dump using integrated biotechnological approach. 10 refs., 5 tabs

  6. Phytoremediation of coal mine spoil dump through integrated biotechnological approach

    Energy Technology Data Exchange (ETDEWEB)

    Juwarkar, A.A.; Jambhulkar, H.P. [National Environmental Engineering Research Institute, Nagpur (India)

    2008-07-15

    Field experiment was conducted on mine spoil dump on an area of 10 ha, to restore the fertility and productivity of the coal mine spoil dump using integrated biotechnological approach. The approach involves use of effluent treatment plant sludge (ETP sludge), as an organic amendment, biofertilizers and mycorrihzal fungi along with suitable plant species. The results of the study indicated that amendment with effluent treatment plant sludge (ETP sludge), at 50 ton/ha improved the physico-chemical properties of coal mine spoil. Due to biofertilizer inoculation different microbial groups such as Rhizobium, Azotobacter and VAM spores, which were practically absent in mine spoil improved greatly. Inoculation of biofertilizer and application of ETP sludge helped in reducing the toxicity of heavy metals such as chromium, zinc, copper, iron, manganese lead, nickel and cadmium, which were significantly reduced to 41%, 43%, 37%, 37%, 34%, 39%, 37% and 40%, respectively, due to the increased organic matter content in the ETP sludge and its alkaline pH (8.10-8.28), at which the metals gets immobilized and translocation of metals is arrested. Thus, amendment and biofertilizer application provided better supportive material for anchorage and growth of the plant on coal mine spoil dump.

  7. Scanning Electron Microscope Studies of Interactions between Agaricus bisporus (Lang) Sing Hyphae and Bacteria in Casing Soil

    OpenAIRE

    Masaphy, Segula; Levanon, D.; Tchelet, R.; Henis, Y.

    1987-01-01

    Relationships between the hyphae of Agaricus bisporus (Lang) Sing and bacteria from the mushroom bed casing layer were examined with a scanning electron microscope. Hyphae growing in the casing layer differed morphologically from compost-grown hyphae. Whereas the compost contained thin single hyphae surrounded by calcium oxalate crystals, the casing layer contained mainly wide hyphae or mycelial strands without crystals. The bacterial population in the hyphal environment consisted of several ...

  8. Revegetation of metalliferous mine spoil contaminated by lead and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M S; McNeilly, T; Putwain, P D

    1977-04-01

    Plant growth and development on metalliferous mine spoil is restricted by the high concentrations of phytotoxic metals and by the low levels of macronutrients in the substrates. Swards established on innocuous amendments applied to the surface of mine spoil deteriorate when roots penetrate to the underlying toxic substratum. This deterioration is attributed to the accumulation of toxic metals. The rate of decline is determined by the inherent fertility of the amendment and the depth to which it is applied. Results of field trials on calcareous and acidic lead/zinc spoils indicate that inert amendments may be more suitable where revegetation is for amenity or recreational purposes. Legumes are essential components of low-maintenance swards established on substrates of low nutrient status.

  9. 30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

  10. 30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

  11. From chemolithoautotrophs to electrolithoautotrophs: CO2 fixation by Fe(II)-oxidizing bacteria coupled with direct uptake of electrons from solid electron sources.

    Science.gov (United States)

    Ishii, Takumi; Kawaichi, Satoshi; Nakagawa, Hirotaka; Hashimoto, Kazuhito; Nakamura, Ryuhei

    2015-01-01

    At deep-sea vent systems, hydrothermal emissions rich in reductive chemicals replace solar energy as fuels to support microbial carbon assimilation. Until recently, all the microbial components at vent systems have been assumed to be fostered by the primary production of chemolithoautotrophs; however, both the laboratory and on-site studies demonstrated electrical current generation at vent systems and have suggested that a portion of microbial carbon assimilation is stimulated by the direct uptake of electrons from electrically conductive minerals. Here we show that chemolithoautotrophic Fe(II)-oxidizing bacterium, Acidithiobacillus ferrooxidans, switches the electron source for carbon assimilation from diffusible Fe(2+) ions to an electrode under the condition that electrical current is the only source of energy and electrons. Site-specific marking of a cytochrome aa3 complex (aa3 complex) and a cytochrome bc1 complex (bc1 complex) in viable cells demonstrated that the electrons taken directly from an electrode are used for O2 reduction via a down-hill pathway, which generates proton motive force that is used for pushing the electrons to NAD(+) through a bc1 complex. Activation of carbon dioxide fixation by a direct electron uptake was also confirmed by the clear potential dependency of cell growth. These results reveal a previously unknown bioenergetic versatility of Fe(II)-oxidizing bacteria to use solid electron sources and will help with understanding carbon assimilation of microbial components living in electronically conductive chimney habitats.

  12. Metabolism of Fructophilic Lactic Acid Bacteria Isolated from the Apis mellifera L. Bee Gut: Phenolic Acids as External Electron Acceptors

    Science.gov (United States)

    Filannino, Pasquale; Addante, Rocco; Pontonio, Erica; Gobbetti, Marco

    2016-01-01

    ABSTRACT Fructophilic lactic acid bacteria (FLAB) are strongly associated with the gastrointestinal tracts (GITs) of Apis mellifera L. worker bees due to the consumption of fructose as a major carbohydrate. Seventy-seven presumptive lactic acid bacteria (LAB) were isolated from GITs of healthy A. mellifera L. adults, which were collected from 5 different geographical locations of the Apulia region of Italy. Almost all of the isolates showed fructophilic tendencies: these isolates were identified as Lactobacillus kunkeei (69%) or Fructobacillus fructosus (31%). A high-throughput phenotypic microarray targeting 190 carbon sources was used to determine that 83 compounds were differentially consumed. Phenotyping grouped the strains into two clusters, reflecting growth performance. The utilization of phenolic acids, such as p-coumaric, caffeic, syringic, or gallic acids, as electron acceptors was investigated in fructose-based medium. Almost all FLAB strains showed tolerance to high phenolic acid concentrations. p-Coumaric acid and caffeic acid were consumed by all FLAB strains through reductases or decarboxylases. Syringic and gallic acids were partially metabolized. The data collected suggest that FLAB require external electron acceptors to regenerate NADH. The use of phenolic acids as external electron acceptors by the 4 FLAB showing the highest phenolic acid reductase activity was investigated in glucose-based medium supplemented with p-coumaric acid. Metabolic responses observed through a phenotypic microarray suggested that FLAB may use p-coumaric acid as an external electron acceptor, enhancing glucose dissimilation but less efficiently than other external acceptors such as fructose or pyruvic acid. IMPORTANCE Fructophilic lactic acid bacteria (FLAB) remain to be fully explored. This study intends to link unique biochemical features of FLAB with their habitat. The quite unique FLAB phenome within the group lactic acid bacteria (LAB) may have practical relevance

  13. A simple and low-toxic method of preparing small specimens of bacteria, flagellates and their likes for Scanning Electron Microscopy

    DEFF Research Database (Denmark)

    Møller, O. S.; Buchman, K.; Dalsgaard, Inger

    2013-01-01

    The preparation of samples of bacteria and other very small organisms (Electron Microscopy is often complex and intricate, which typically involve the use of specialized filter systems, complex handling and toxic chemicals. Based on the methods described in the literature...

  14. Distribution of vesicular-arbuscular mycorrhizal fungi in coal, lignite and calcite mine spoils of India

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, V.; Ragupathy, S.; Parthipan, B.; Rani, D.B.R.; Mahadevan, A.

    1991-12-31

    Vesicular-arbuscular mycorhizzal (VAM) status was assessed for coal, lignite and calcite mine spoils. The three study sites were: The Kothagudem coal field in the south central region where waste materials are piled 1 to 2 m high on the soil surface. Samples were collected from plants growing on the waste. Neyveli, on the southeastern coast, is a lignite coal mine where the spoil is piled 70 to 100 m high on the soil surface. Samples were collected from recently revegetated mine spoil and from 25 year old revegetated sites. The calcite mine at Thazhaiyuthu in the south where the spoil is piled up 2 to 3 m on the soil surface. Samples were collected from 4 to 7 year old reclaimed sites. The wastes generally supported different plant species. The level of VAM infection of plants was markedly different in each mine spoil, with the maximum infection in the coal and calcite spoils, and the least in the lignite spoil. There was more infection in the 25 year old lignite spoil than in the newly revegetated spoil. There were different VAM species in each spoil, and no one species was present in all of the samples. The authors conclude that one of the factors leading to the differences between spoils is the amount of topsoil contained in the spoil (least in the lignite spoils which are very deep). The other is age of the spoils. Unfortunately the authors concluded that the best approach is to enrich the spoils with VAM rather than salvaging and replacing topsoil

  15. Flow cytometric viability assessment and transmission electron microscopic morphological study of Bacteria in Glycerol

    NARCIS (Netherlands)

    Saegeman, V.S.M.; Vos, de R.; Tebaldi, N.D.; Wolf, van der J.M.; Bergervoet, J.H.W.; Verhaegen, J.; Lismont, D.; Verduyckt, B.; Ectors, N.L.

    2007-01-01

    Human cadaveric skin allografts are used in the treatment of burns and can be preserved in glycerol at high concentrations. Previously, glycerol has been attributed some antimicrobial effect. In an experimental set-up, we aimed at investigating this effect of prolonged incubation of bacteria in 85%

  16. Scanning Electron Microscope Studies of Interactions between Agaricus bisporus (Lang) Sing Hyphae and Bacteria in Casing Soil

    Science.gov (United States)

    Masaphy, Segula; Levanon, D.; Tchelet, R.; Henis, Y.

    1987-01-01

    Relationships between the hyphae of Agaricus bisporus (Lang) Sing and bacteria from the mushroom bed casing layer were examined with a scanning electron microscope. Hyphae growing in the casing layer differed morphologically from compost-grown hyphae. Whereas the compost contained thin single hyphae surrounded by calcium oxalate crystals, the casing layer contained mainly wide hyphae or mycelial strands without crystals. The bacterial population in the hyphal environment consisted of several types, some attached to the hyphae with filamentlike structures. This attachment may be important in stimulation of pinhead initiation. Images PMID:16347340

  17. Phytoremediation of spoil coal dumps in Western Donbass (Ukraine)

    Science.gov (United States)

    Klimkina, Iryna; Kharytonov, Mykola; Wiche, Oliver; Heilmeier, Hermann

    2017-04-01

    At the moment, in Ukraine about 150 thousand hectares of fertile land are occupied by spoil dumps. Moreover, this figure increases every year. According to the technology used about 1500 m3 of adjacent stratum is dumped at the surface per every 1000 tons of coal mined. Apart from land amortization, waste dumps drastically change the natural landscape and pollute air, soil and water sources as the result of water and wind erosion, as well as self-ignition processes. A serious concern exists with respect to the Western Donbass coal mining region in Ukraine, where the coal extraction is made by the subsurface way and solid wastes are represented by both spoil dumps and wastes after coal processing. Sulphides, mostly pyrite (up to 4% of waste material), are widely distributed in the waste heaps freshly removed due to coal mining in Western Donbass.The oxidation of pyrite with the presence of oxygen and water is accompanied by a sharp drop in the pH from the surface layer to the spoil dumps(from 5.2-6.2 to 3.9-4.2 in soil substrates with chernozen and from 8.3-8.4 to 6.7-7.2 in soil substrates with red-brown clay, stabilizing in dump material in both cases at 2.9-3.2). Low pH generates the transformation of a number of toxic metals and other elementspresent in waste rock (e.g. Fe, Al, Mn, Zn, Mo, Co, As, Cd, Bi, Pb, U) into mobile forms. To stabilize and reduce metal mobility the most resistant plants that occur naturally in specified ecosystems can be used. On coal spoil dumpsin Western Donbas the dominant species are Bromopsis inermis, subdominant Artemisia austriaca; widespread are also Festucas pp., Lathyrus tuberosus, Inula sp., Calamagrostis epigeios, Lotus ucrainicus, and Vicias pp. Identification of plants tolerant to target metals is a key issue in phytotechnology for soil restoration. It is hypothesized that naturally occurring plants growing on coal spoil dumps can be candidates for phytostabilization, phytoextraction (phytoaccumulation) and phytomining

  18. Direct interaction between linear electron transfer chains and solute transport systems in bacteria

    NARCIS (Netherlands)

    Elferink, Marieke G.L.; Hellingwerf, Klaas J.; Belkum, Marco J. van; Poolman, Bert; Konings, Wil N.

    1984-01-01

    In studies on alanine and lactose transport in Rhodopseudomonas sphaeroides we have demonstrated that the rate of solute uptake in this phototrophic bacterium is regulated by the rate of light-induced cyclic electron transfer. In the present paper the interaction between linear electron transfer

  19. Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria.

    Science.gov (United States)

    Filannino, Pasquale; Gobbetti, Marco; De Angelis, Maria; Di Cagno, Raffaella

    2014-12-01

    The metabolism of hydroxycinnamic acids by strictly heterofermentative lactic acid bacteria (19 strains) was investigated as a potential alternative energy route. Lactobacillus curvatus PE5 was the most tolerant to hydroxycinnamic acids, followed by strains of Weissella spp., Lactobacillus brevis, Lactobacillus fermentum, and Leuconostoc mesenteroides, for which the MIC values were the same. The highest sensitivity was found for Lactobacillus rossiae strains. During growth in MRS broth, lactic acid bacteria reduced caffeic, p-coumaric, and ferulic acids into dihydrocaffeic, phloretic, and dihydroferulic acids, respectively, or decarboxylated hydroxycinnamic acids into the corresponding vinyl derivatives and then reduced the latter compounds to ethyl compounds. Reductase activities mainly emerged, and the activities of selected strains were further investigated in chemically defined basal medium (CDM) under anaerobic conditions. The end products of carbon metabolism were quantified, as were the levels of intracellular ATP and the NAD(+)/NADH ratio. Electron and carbon balances and theoretical ATP/glucose yields were also estimated. When CDM was supplemented with hydroxycinnamic acids, the synthesis of ethanol decreased and the concentration of acetic acid increased. The levels of these metabolites reflected on the alcohol dehydrogenase and acetate kinase activities. Overall, some biochemical traits distinguished the common metabolism of strictly heterofermentative strains: main reductase activity toward hydroxycinnamic acids, a shift from alcohol dehydrogenase to acetate kinase activities, an increase in the NAD(+)/NADH ratio, and the accumulation of supplementary intracellular ATP. Taken together, the above-described metabolic responses suggest that strictly heterofermentative lactic acid bacteria mainly use hydroxycinnamic acids as external acceptors of electrons. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Usage of ferrum (ІІІ and manganese (IV ions as electron acceptors by Desulfuromonas sp. bacteria

    Directory of Open Access Journals (Sweden)

    O. M. Moroz

    2016-03-01

    Full Text Available The toxicity of metal ions to microorganisms, in particular at high concentrations, is one of the main impediments to their usage in remediation technologies. The purpose of this work is to analyze the possibility of usage by bacteria of the Desulfuromonas genus, isolated by us from Yavorivske Lake, of ferrum (ІІІ and manganese (IV ions at concentrations in the medium of 1,74–10,41 mM as electron acceptors of anaerobic respiration to assesss resistance of sulphur reducing bacteria strains to heavy metal compounds. Cells of Desulfuromonas acetoxidans ІМV V-7384, Desulfuromonas sp. Yavor-5 and Desulfuromonas sp. Yavor-7 were cultivated for 10 days at 30 °C under anaerobic conditions in Kravtsov-Sorokin’s medium without sulphate ions, sulphur, with cysteine as the sulphur source (0.2 g/l and sodium lactate or citrate as the electron donor (17.86 g/l, in which were added sterile 1 M solutions of C6H5O7Fe and C4H4O4 (control and also weights of MnO2 to their terminal concentrations 1.74, 3.47, 5.21, 6.94, 10.41 mM. Biomass was determined by the turbidimetric method. In the culture liquid the presence of Fe3+ and Mn4+ were qualitatively determined, and the content of Fe2+ in reaction with о-phenanthroline was determined quantitatively. It was established that sulphur reducing bacteria used with different intensity ferrum (ІІІ and manganese (IV ions as electron acceptors during the process of anaerobic respiration at concentrations of 1.74–10.41 mM C6H5O7Fe and MnO2 in the medium, which demonstrated the important role of the investigated microorganisms in reductive detoxication of natural and technogenic media from oxidized forms of transitional heavy metals. An insignificant difference in biomass accumulation during usage of 5.21–10.41 mM ferrum (ІІІ ions and fumarate is caused by toxicity of the metal ions to cells since the high redox potential of the Fe(III/Fe(ІІ pair with increase in concentrations of electron acceptors in

  1. Prediction of the acid generating potential of coal mining spoils

    International Nuclear Information System (INIS)

    Monterroso, C.; Macias, F.

    1998-01-01

    The sulfide oxidation impact on mined land reclamation makes it necessary for mine spoils to be classified according to their acidifying potential. In this paper predictions were made of the acid generating potential of sulfide-containing spoils from the Puentes lignite mine (Galicia, NW Spain), and the limits of sulfur contents allowable for their storage in aerobic conditions, were established. Using samples of fresh spoils, analyses were made of the content and speciation of sulfur, pH was measured after oxidation of the sample with H 2 O 2 (pH of oxidation = pH OX ), and titration of the oxidation extract with 0.1N NaOH to pH = 7 was carried out (Net Acid Production = NAP). The total sulfur content (S T ) varied between 3%, with pyritic-S being the most common form (> 80%). pH OX varied between 1.6 and 6.4 and NAP between 1.2 and 85.0 Kg-CaCO 3 t -1 . A high correlation was found between the NAP and the S T (r-0.98, p T > 0.15% cause high risks of mine-soil acidification, and create the need for large doses of CaCO 3 to be used on final surface of the mine dump. Use of fly ash, produced from the combustion of lignite, as an alternative to commercial lime is more effective in the control of acidity generated by spoils with high S T . 20 refs., 5 figs., 1 tab

  2. Depletion-Mode GaN HEMT Q-Spoil Switches for MRI Coils.

    Science.gov (United States)

    Lu, Jonathan Y; Grafendorfer, Thomas; Zhang, Tao; Vasanawala, Shreyas; Robb, Fraser; Pauly, John M; Scott, Greig C

    2016-12-01

    Q-spoiling is the process of decoupling an MRI receive coil to protect the equipment and patient. Conventionally, Q-spoiling is performed using a PIN diode switch that draws significant current. In this work, a Q-spoiling technique using a depletion-mode Gallium Nitride HEMT device was developed for coil detuning at both 1.5 T and 3 T MRI. The circuits with conventional PIN diode Q-spoiling and the GaN HEMT device were implemented on surface coils. SNR was measured and compared for all surfaces coils. At both 1.5 T and 3 T, comparable SNR was achieved for all coils with the proposed technique and conventional Q-spoiling. The GaN HEMT device has significantly reduced the required power for Q-spoiling. The GaN HEMT device also provides useful safety features by detuning the coil when unpowered.

  3. Communication: Coherences observed in vivo in photosynthetic bacteria using two-dimensional electronic spectroscopy

    International Nuclear Information System (INIS)

    Dahlberg, Peter D.; Norris, Graham J.; Wang, Cheng; Viswanathan, Subha; Singh, Ved P.; Engel, Gregory S.

    2015-01-01

    Energy transfer through large disordered antenna networks in photosynthetic organisms can occur with a quantum efficiency of nearly 100%. This energy transfer is facilitated by the electronic structure of the photosynthetic antennae as well as interactions between electronic states and the surrounding environment. Coherences in time-domain spectroscopy provide a fine probe of how a system interacts with its surroundings. In two-dimensional electronic spectroscopy, coherences can appear on both the ground and excited state surfaces revealing detailed information regarding electronic structure, system-bath coupling, energy transfer, and energetic coupling in complex chemical systems. Numerous studies have revealed coherences in isolated photosynthetic pigment-protein complexes, but these coherences have not been observed in vivo due to the small amplitude of these signals and the intense scatter from whole cells. Here, we present data acquired using ultrafast video-acquisition gradient-assisted photon echo spectroscopy to observe quantum beating signals from coherences in vivo. Experiments were conducted on isolated light harvesting complex II (LH2) from Rhodobacter sphaeroides, whole cells of R. sphaeroides, and whole cells of R. sphaeroides grown in 30% deuterated media. A vibronic coherence was observed following laser excitation at ambient temperature between the B850 and the B850 ∗ states of LH2 in each of the 3 samples with a lifetime of ∼40-60 fs

  4. Communication: Coherences observed in vivo in photosynthetic bacteria using two-dimensional electronic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dahlberg, Peter D. [Graduate Program in the Biophysical Sciences, Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States); Norris, Graham J.; Wang, Cheng; Viswanathan, Subha; Singh, Ved P.; Engel, Gregory S., E-mail: gsengel@uchicago.edu [Department of Chemistry, Institute for Biophysical Dynamics, and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    2015-09-14

    Energy transfer through large disordered antenna networks in photosynthetic organisms can occur with a quantum efficiency of nearly 100%. This energy transfer is facilitated by the electronic structure of the photosynthetic antennae as well as interactions between electronic states and the surrounding environment. Coherences in time-domain spectroscopy provide a fine probe of how a system interacts with its surroundings. In two-dimensional electronic spectroscopy, coherences can appear on both the ground and excited state surfaces revealing detailed information regarding electronic structure, system-bath coupling, energy transfer, and energetic coupling in complex chemical systems. Numerous studies have revealed coherences in isolated photosynthetic pigment-protein complexes, but these coherences have not been observed in vivo due to the small amplitude of these signals and the intense scatter from whole cells. Here, we present data acquired using ultrafast video-acquisition gradient-assisted photon echo spectroscopy to observe quantum beating signals from coherences in vivo. Experiments were conducted on isolated light harvesting complex II (LH2) from Rhodobacter sphaeroides, whole cells of R. sphaeroides, and whole cells of R. sphaeroides grown in 30% deuterated media. A vibronic coherence was observed following laser excitation at ambient temperature between the B850 and the B850{sup ∗} states of LH2 in each of the 3 samples with a lifetime of ∼40-60 fs.

  5. Triplet states of carotenoids from photosynthetic bacteria studied by nanosecond ultraviolet and electron pulse irradiation

    International Nuclear Information System (INIS)

    Bensasson, R.; Land, E.J.; Maudinas, B.

    1976-01-01

    Absorptions of the triplet excited states of five carotenoids (15,15'-cis phytoene, all-trans phytoene, zeta-carotene, spheroidene and spirillox-anthin), extracted from the photosynthetic bacteria Rhodopseudomonas spheroides and Rhodospirillum rubrum, have been detected in solution using pulse radiolysis and laser flash photolysis. Triplet lifetimes, extinction coefficients, lowest energy levels and quantum efficiencies of formation have been determined. Comparison of the carotenoid triplet energy levels with that of O 2 ('Δsub(g)) suggests that spirilloxanthin, spheroidene and possibly also zeta-carotene, would be expected to protect against photodynamic action caused by O 2 ('Δsub(g)), but not cis or trans phytoene. The S → T intersystem crossing efficiencies of all five polyenes were found to be low, being a few per cent or less. In their protective role these triplet states can only therefore be effectively reached via energy transfer from another triplet, except in the case of O 2 (Δsub(g)). The low crossover efficiencies also mean that light absorbed in such carotenoids in their possible role as accessory pigments would not be wasted in crossing over to the triplet state. (author)

  6. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    International Nuclear Information System (INIS)

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo; Hayashi, Toru; Yasumoto, Kyoden.

    1990-01-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

  7. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo [Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries; Hayashi, Toru; Yasumoto, Kyoden

    1990-10-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author).

  8. Reclamation of colliery mine spoil founded on natural succession

    International Nuclear Information System (INIS)

    Jochimsen, M.E.A.

    1996-01-01

    Reclamation of derelict land is of great concern for industrial countries. Technically produced and biologically inactive soils are said to be hostile to plants. Therefore, great effort is applied, in order to reintegrate them into the landscape. Ordinarily plant settlement starts with pioneer plants, especially herbs. Reafforestation, in this case, is an ecological misunderstanding. A method of mimicking natural succession including its ecological and economic advantages is described. The results of an applied experiment on virgin mine spoil with respect to species number, plant cover degree, and above ground phytomass production in the course of six years are reported in this paper. 12 refs., 4 figs

  9. Studying antimicrobial-induced morphostructural damage of bacteria by Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    Shruti Shukla

    2015-12-01

    Full Text Available In this investigation, a scanning electron microscopy (SEM method was used to examine the morphostructural changes in bacterial cells induced by antimicrobial agents. SEM-based visual approach is referred the study of bacterial cells and their physiological consequences when affected by antibiotics or antibacterial agents permitting the observation of characteristic morphological defects of cell wall, and provides valuable insights into processes involved in bacterial cell death. This experiment visualized various step-by-step techniques used in the slide preparation of bacterial cells treated with specific antimicrobial agent for analyzing the morphological alterations such as increase of cell wall roughness, cell disruption, cell swelling and lysed cell formation due to loss of intracellular material using SEM analysis when compared with untreated normal cells as a control. The SEM approach used in this visual experiment may analyze the antimicrobial effect of any commercially known or new compounds in a very conducive manner.

  10. Assessment of the application of an automated electronic milk analyzer for the enumeration of total bacteria in raw goat milk.

    Science.gov (United States)

    Ramsahoi, L; Gao, A; Fabri, M; Odumeru, J A

    2011-07-01

    Automated electronic milk analyzers for rapid enumeration of total bacteria counts (TBC) are widely used for raw milk testing by many analytical laboratories worldwide. In Ontario, Canada, Bactoscan flow cytometry (BsnFC; Foss Electric, Hillerød, Denmark) is the official anchor method for TBC in raw cow milk. Penalties are levied at the BsnFC equivalent level of 50,000 cfu/mL, the standard plate count (SPC) regulatory limit. This study was conducted to assess the BsnFC for TBC in raw goat milk, to determine the mathematical relationship between the SPC and BsnFC methods, and to identify probable reasons for the difference in the SPC:BsnFC equivalents for goat and cow milks. Test procedures were conducted according to International Dairy Federation Bulletin guidelines. Approximately 115 farm bulk tank milk samples per month were tested for inhibitor residues, SPC, BsnFC, psychrotrophic bacteria count, composition (fat, protein, lactose, lactose and other solids, and freezing point), and somatic cell count from March 2009 to February 2010. Data analysis of the results for the samples tested indicated that the BsnFC method would be a good alternative to the SPC method, providing accurate and more precise results with a faster turnaround time. Although a linear regression model showed good correlation and prediction, tests for linearity indicated that the relationship was linear only beyond log 4.1 SPC. The logistic growth curve best modeled the relationship between the SPC and BsnFC for the entire sample population. The BsnFC equivalent to the SPC 50,000 cfu/mL regulatory limit was estimated to be 321,000 individual bacteria count (ibc)/mL. This estimate differs considerably from the BsnFC equivalent for cow milk (121,000 ibc/mL). Because of the low frequency of bulk tank milk pickups at goat farms, 78.5% of the samples had their oldest milking in the tank to be 6.5 to 9.0 d old when tested, compared with the cow milk samples, which had their oldest milking at 4 d

  11. Inactivation of spoiling microorganisms in apple juice by a combination of essential oils' constituents and physical treatments.

    Science.gov (United States)

    Chueca, Beatriz; Ramírez, Nayeli; Arvizu-Medrano, Sofía M; García-Gonzalo, Diego; Pagán, Rafael

    2016-07-01

    A combination of different hurdles, such as mild heat (54 ℃ for 10 min) or pulsed electric field (25 pulses; 25 kV/cm; 3.35 kJ/cm per pulse) treatments and essential oils constituents (carvacrol, citral, and (+)-limonene), to reduce spoiling bacteria and yeasts in apple juice was evaluated. For this purpose, the heat and pulsed electric field resistances of five strains of Leuconostoc spp. and five Saccharomyces spp. strains were assayed, achieving different inactivation levels for each treatment and strain. For instance, Leuconostoc fallax 74, the most heat-resistant strain, was the second-most sensitive strain to pulsed electric field. The most resistant strains were exposed to combined processes of heat or pulsed electric field and 0.2 µl/ml essential oils constituents. The combination of heat and essential oils constituents proved to be synergistic against both microorganisms in apple juice. The most effective was the combination of mild heat and carvacrol, which caused the inactivation of 99% of L. fallax 74 and 99.99% of Saccharomyces cerevisiae CECT 1172 cells. Therefore, this study shows the great potential of carvacrol, citral, and (+)-limonene in combined treatments with mild heat to achieve a higher degree of inactivation of spoiling microorganisms in apple juice, and thus, to extend its shelf life. © The Author(s) 2015.

  12. Reestablishing natural succession on acidic mine spoils at high elevations: long-term ecological restoration

    Science.gov (United States)

    Ray W. Brown; Michael C. Amacher; Walter F. Mueggler; Janice Kotuby-Amacher

    2003-01-01

    Methods for restoring native plant communities on acidic mine spoils at high elevations were evaluated in a "demonstration area" in the New World Mining District of southern Montana. Research plots installed in 1976 were assessed for 22 years and compared with adjacent native reference plant communities. A 1.5-acre (0.61-ha) area of mine spoils was shaped and...

  13. Initial vesicular-arbuscular mycorrhizal development of slender wheatgrass on two amended mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Zak, J.C.; Parkinson, D. (University of Calgary, Calgary, AB (Canada). Dept. of Biology)

    1982-01-01

    The initial vesicular-arbuscular (VA) mycorrhizal development of slender wheatgrass on extracted oil-sands and subalpine coal-mine spoils, amended with either fertilizer, peat, or liquid sewage sludge, was examined. Plants were sampled at 2,6 and 10 weeks after plant emergence and the level of infection was expressed as length of mycorrhizal root per plant and length of root which contained arbuscules, vesicles, or only hyphae. Mycorrhizal infection of slender wheatgrass on the oil sands was limited to plants on the peat-amended spoil. Infection of plants on the peat-amended oil-sands spoil was detected by 2 weeks. Plants on the subalpine spoil were infected at 2 weeks only on the peat-amended spoil. While slender wheatgrass on the control and fertilizer-amended spoil developed mycorrhizae by 6 weeks, infection was not observed in plants on the sewage-amended spoil until 10 weeks. At 10 weeks, there were no significant differences in lengths of mycorrhizal root per plant among the amendments. Increased P levels in the fertilizer- and sewage-amended subalpine spoil did not suppress VA mycorrhizal development. 43 refs., 6 tabs.

  14. Revegetation of Alaskan coal mine spoils. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, W W; Mitchell, G A; McKendrick, J D

    1980-05-23

    Activities initiated after the start of the revegetation project on Alaskan coal mine spoils on September 1, 1979 have consisted mainly of some fall plantings (dormant seedings) and soil and coal spoil samplings and analyses. Because of the late summer start for the project, only a limited amount of field work could be initiated in plant material studies. This consisted of a fall planting at the Usibelli mine site at Healy in interior Alaska. The planting was intended to test the efficacy of seeding in the frost period following the growing season, requiring the seed to remain dormant over winter and to germinate when conditions become favorable in late spring. It also was intended as a comparison of a number of different grasses. Thirty entries were seeded in three replications. Fifteen species of grasses and a clover were included in the trial. The site provided for the trial was on overburden material along a streambed. Among the entries were eight cultivars of introduced grasses, five cultivars of native Alaskan germplasm, one introduced clover cultivar, and sixteen experimental grasses mainly of Alaskan origin.

  15. Vegetational stabilization of uranium spoil areas, grants, New Mexico

    International Nuclear Information System (INIS)

    Kelley, N.E.

    1979-01-01

    Factors that could be detrimental to vegetative stabilization of uranium mine and mill waste material were examined. Physical and chemical analyses of materials from an open-pit uranium mine and material from three inactive mill tailing piles in New Mexico were performed. Analyses for selected trace elements in mill tailing material and associated vegetation from piles in New Mexico, Colorado, and Utah were also performed. Field and laboratory experiments identified problems associated with establishing vegetation on spoil material. Problems of uptake and concentration of toxic elements by plants growing on specific spoil material were also identified. Ecological observations in conjunction with physical and chemical analyses of specific geologic units, which form the overburden and waste dumps at the open-pit mine, identified a specific geologic material that, if segregated and placed on the surface of the dumps, would pose the least set of problems for a revegetation program. A pilot revegetation project verified that segregation and use of specific geologic material in the overburden could be utilized successfully and economically for reestablishment of native vegetation on mine waste material

  16. Bryophytes and revegetation of coal spoils in southern Iowa. [14 refs

    Energy Technology Data Exchange (ETDEWEB)

    Carvey, K.; Farrar, D.R.; Glenn-Lewin, D.C.

    1976-01-01

    Strip mining of coal in southern Iowa has left many scattered areas of coal spoils which provide a type of habitat unique to the region. The occurrence and distribution of 29 mosses and 2 liverworts on these spoils was determined and related to the general process of spoil revegetation. The spoil bryophyte flora was compared with Conard's (1956) list of bryophytes for the region. An increase in per cent cover and in species diversity of bryophytes was observed with increasing age of spoils, and was correlated with increased vascular plant cover. Dicranella heteromalla and Ceratodon purpureus were found to be common throughout the spoils, whereas all other species were limited to more protected sites, especially on north-facing slopes. Mosses did not appear to colonize very exposed areas on the spoils, but were limited to areas with some protection provided, especially by vascular plants. Several disjunct or highly localized moss populations were found including one new state record and thirteen new county records.

  17. Accumulation of some metals by legumes and their extractability from acid mine spoils

    International Nuclear Information System (INIS)

    Taylor, R.W.; Ibeabuchi, I.O.; Sistani, K.R.; Shuford, J.W.

    1992-01-01

    A greenhouse study was conducted to investigate the growth (dry matter yield) of selected legume cover crops; phytoaccumulation of metals such as Zn, Mn, Pb, Cu, Ni, and Al; the extractability of heavy metals from three different Alabama acid mine spoils. The spoils were amended based on soil test recommended levels of N, P, K, Ca and Mg prior to plant growth. Metals were extracted by three extractants (Mehlich 1, DTPA, and 0.1 M HCl) and values correlated with their accumulation by the selected legumes. Among the cover crops, kobe lespedeza Lespedeza striata (Thung.) Hook and Arn, sericea lespedeza Lespedeza cuneata (Dum.) G. Don, and red clover (Trifolium pratense L.) did not survive the stressful conditions of the spoils. However, cowpea (Vigna unguiculata L.) followed by 'Bragg' soybean Glycine max (L.) Merr. generally produced the highest dry matter yield while accumulating the largest quantity of metals, except Al, from spoils. The extractability of most metals from the spoils was generally in the order of: 0.1 MHCl > DTPA. Mehlich 1 did not extract Pb and 0.1 M HCl did not extract Ni, whereas DTPA extracted all the metals in a small amount relative to HCl and Mehlich 1. All the extractants were quite effective in removing plant-available Zn from the spoils. In general, the extractants' ability to predict plant-available metals depended on the crop species, spoil type, and extractant used. 28 refs., 4 tabs

  18. Selenium transformation in coal mine spoils: Its environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Harness, J.; Atalay, A.; Koll, K.J.; Zhang, H.; Maggon, D.

    1991-12-31

    The objective of this program was to conduct an environmental impact assessment study for selenium from coal mine spoils. The use of in-situ lysimetry to predict selenium speciation, transformation, and mobility under natural conditions was evaluated. The scope of the study was to construct and test field-scale lysimeter and laboratory mini-column to assess mobility and speciation of selenium in coal mine overburden and soil systems; to conduct soil and groundwater sampling throughout the state of Oklahoma for an overall environmental impact assessment of selenium; and to conduct an in-depth literature review on the solubility, speciation, mobility, and toxicity of selenium from various sources. Groundwater and surface soil samples were also collected from each county in Oklahoma. Data collected from the lysimeter study indicated that selenium in the overburden of the abandoned mine site was mainly found in the selenite form. The amount of selenite found was too low and immobile to be of concern to the environment. The spoil had equilibrated long enough (over 50 years) that most of the soluble forms of selenium have already been lost. Examination of the overburden indicated the presence of pyrite crystals that precipitated over time. The laboratory mini-column study indicated that selenite is quite immobile and remained on the overburden material even after leaching with dilute acid. Data from groundwater samples indicated that based on the current permissible level for selenium in groundwater (0.01 mg Se/L), Oklahoma groundwater is widely contaminated with the element. However, according to the new regulation (0.05 mg Se/L), which is to be promulgated in 1992, only 9 of the 77 counties in the state exceed the limit.

  19. Anaerobic bacteria

    Science.gov (United States)

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  20. Heavy metal concentration in forage grasses and extractability from some acid mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.W.; Ibeabuchi, I.O.; Sistani, K.R.; Shuford, J.W. (Alabama A and M University, Normal (United States). Department of Plant and Soil Science)

    1993-06-01

    Laboratory and greenhouse studies were conducted on several forage grasses, bermudagrass ([ital Cynodon dactylon]), creeping red fescue ([ital Festuca rubra]), Kentucky 31-tall fescue ([ital Festuca arundinacea]), oat ([ital Avena sativa]), orchardgrass ([ital Dactylis glomerata]), perennial ryegrass ([ital Lolium perenne]), sorghum ([ital Sorghum bicolor]), triticale (X. [ital triticosecale Wittmack]), and winter wheat ([ital Triticum aestivum]) grown on three Alabama acid mine spoils to study heavy metal accumulation, dry matter yield and spoil metal extractability by three chemical extractants (Mehlich 1, DTPA, and 0.1 M HCl). Heavy metals removed by these extractants were correlated with their accumulation by several forage grasses. Among the forages tested, creeping red fescue did not survive the stressful conditions of any of the spoils, while orchard grass and Kentucky 31-tall fescue did not grow in Mulberry spoil. Sorghum followed by bermudagrass generally produced the highest dry matter yield. However, the high yielding bermudagrass was most effective in accumulating high tissue levels of Mn and Zn from all spoils (compared to the other grasses) but did not remove Ni. On the average, higher levels of metals were extracted from spoils in the order of 0.1 M HCl[gt] Mehlich 1[gt] DTPA. However, DTPA extracted all the metals from spoils while Mehlich 1 did not extract Pb and 0.1 M HCl did not extract detectable levels of Ni. All of the extractants were quite effective in determining plant available Zn from the spoils. For the other metals, the effective determination of plant availability depended on the crop, the extractant, and the metal in concert. 20 refs., 6 tabs.

  1. Identification of ecotype-specific marker genes for categorization of beer-spoiling Lactobacillus brevis.

    Science.gov (United States)

    Behr, Jürgen; Geissler, Andreas J; Preissler, Patrick; Ehrenreich, Armin; Angelov, Angel; Vogel, Rudi F

    2015-10-01

    The tolerance to hop compounds, which is mainly associated with inhibition of bacterial growth in beer, is a multi-factorial trait. Any approaches to predict the physiological differences between beer-spoiling and non-spoiling strains on the basis of a single marker gene are limited. We identified ecotype-specific genes related to the ability to grow in Pilsner beer via comparative genome sequencing. The genome sequences of four different strains of Lactobacillus brevis were compared, including newly established genomes of two highly hop tolerant beer isolates, one strain isolated from faeces and one published genome of a silage isolate. Gene fragments exclusively occurring in beer-spoiling strains as well as sequences only occurring in non-spoiling strains were identified. Comparative genomic arrays were established and hybridized with a set of L. brevis strains, which are characterized by their ability to spoil beer. As result, a set of 33 and 4 oligonucleotide probes could be established specifically detecting beer-spoilers and non-spoilers, respectively. The detection of more than one of these marker sequences according to a genetic barcode enables scoring of L. brevis for their beer-spoiling potential and can thus assist in risk evaluation in brewing industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Definition of rehabilitation strategies for pre-strip tertiary spoil at coal mines in central Queensland

    International Nuclear Information System (INIS)

    Bell, L.C.; Mulligan, D.R.; Mitchell, R.J.; Philp, M.W.; Roe, P.A.

    1994-01-01

    In the open-cut coal mines of central Queensland, the conventional dragline removal of overburden results in a spoil surface dominated by Permian sediments. In recent years, however, a number of mines have changed their coal exposure methods to include a pre-stripping operation to create a bench for the dragline up to 50 m below the surface. This approach has allowed economic coal recovery from greater depths, but, since this pre-strip material is being deposited on existing spoil piles, it has resulted in a major change in the type of spoil material on the surface. The aims of this project were, firstly, to define the characteristics of this pre-strip material that could cause problems for the establishment and growth of both introduced pasture grasses and native tree species, and secondly, to explore possible spoil amendments which could ameliorate some or all of these limitations. Analyses on the range of spoils included pH, EC and sodicity. Straw mulch also reduced the crust strength and was an effective means of improving vegetative establishment. A complementary field trial was established at Saraji mine in April 1991, and after 4 months, treatments which involved a 30 cm capping of soil on the spoil resulted in the highest densities of tree seedling

  3. Utilizing sediments from biological waste water treatment for spraying spoil banks

    Energy Technology Data Exchange (ETDEWEB)

    Bobrov, O G; Zaitsev, Yu S; Kessariiskii, Yu V

    1985-04-01

    Use of anaerobic sludge for prevention of spontaneous combustion of spoil banks consisting of coal and mine stones from underground coal mines and effects of sludge treatment on soil properties which influence spoil bank reclamation are discussed. Sludge from water treatment rich in organic matter (50 to 60%), nitrogen (2 to 5%), phosphorus anhydride (up to 2%), calcium oxide (up to 5%) and humus was used in the Donbass. A spoil bank consisted of sedimentary rocks (sandstones, limestones, shales, clays, mudstone) and coal (size 0 to 200 mm). Coal content ranged from 7-13%, sulfur content amounted to about 5%. Content of coal, sulfur and timber exceeded 20%. The spoil bank was treated with sludge suspension in water. Evaluations showed that the sludge treatment improved soil properties which influenced spoil bank reclamation. Humus content increased 7 to 16 times, content of nitrogen trioxide and phosphorus anhydride increased 10 to 50 times. Chemical activity of rocks forming the spoil bank declined 20 to 25%. Hazards of coal spontaneous combustion decreased. The results of investigations are shown in a table.

  4. Reforestation of bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    N. Krishnakumar

    2012-11-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted indegradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth.However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum(Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum(Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings of Eucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings of E. tereticornis showed 95% survival over the control seedlings and their growth was also significantlyhigher. Tissue nutrients (N, P, K were also found higher inAM fungi inoculated E. tereticornis than un inoculated control seedlings.

  5. Reforestation of Bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with Arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    A. Karthikeyan

    2012-12-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted in degradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth. However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum (Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum (Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings ofEucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings ofE. tereticornis showed 95% survival over the control seedlings and their growth was also significantly higher. Tissue nutrients (N, P, K were also found higher in AM fungi inoculated E. tereticornis than un inoculated control seedlings. 

  6. Phytoextraction from mine spoils: insights from New Caledonia.

    Science.gov (United States)

    Losfeld, Guillaume; Mathieu, Romain; L'Huillier, Laurent; Fogliani, Bruno; Jaffré, Tanguy; Grison, Claude

    2015-04-01

    Increasing pressure on mineral resources has drawn research efforts into innovative supply and recycling. Metal-rich biomass produced in phytoextraction recently proved an interesting starting material for green chemistry. It allows the production of new catalysts, referred to as ecocatalysts. Ecocatalysts provide increased yields in chemical production and increased regio- and chemo-selectivity, which result in high added value. This new approach to using metal-rich biomass could spur the development of phytoextraction, a technique considered promising for long, yet without credible economic outlets. In this regard, metallophyte biodiversity hotspots, such as New Caledonia, are of particular interest for biomass supply. Potential phytoextraction from mine spoils using two species endemic to New Caledonia is discussed here. Geissois pruinosa, a hypernickelophore, and Grevillea exul, a Mn accumulator, were selected for these original experiments. The results presented here 20 months after plantation of young trees from a nursery show the interest of the approach. Mean Ni concentrations of up to 1513 mg kg(-1) are reported in G. pruinosa, as well as 2000 mg kg(-1) Mn in G. exul. Concentrations of Ni and Mn in the leaves of each species appear to be correlated with leaf age. Plantation of these species may also ensure mine reclamation, and experiments were conducted with the principles of ecological restoration in mind adding a further dimension to the approach.

  7. Electron-ionic technology of storage of foodstuffs

    International Nuclear Information System (INIS)

    Tsoj, A.P.

    1996-01-01

    Work is trained on reduction of food suffer losses under cold store due to its drying and spoiling. Experimental cold store of fruits in 'microclimates' in electron-ionic medium created with help of pilot unit is carried out

  8. Response of alkali sacaton and fourwing saltbush to various amendments on coal mine spoils from northwestern New Mexico. II. Sodic spoil

    Energy Technology Data Exchange (ETDEWEB)

    Scholl, D G; Miyamoto, S

    1984-03-01

    Effects of chemical amendments on properties of two sodic mine spoils (sandstone and shale origins) and on growth of two range plants (alkali sacaton and fourwing saltbush) were studied in search of promising revegetation methods. The chemical amendments included applications of concentrated sulfuric acid, gypsum and phosphorus. On the shale spoil, these chemicals were applied in combination with physical amendments consisting of sand mulching, sand top-dressing, or sand incorporation. The sand used for the physical amendment was aeolian sand, which is locally available in the mine area. Laboratory water penetration tests and greenhouse plant growth tests were performed. Results indicate the following amendments to be promising: for sandstone-based spoils, sulfuric acid treatment, gypsum plus phosphorus application or phosphorus fertilization alone, depending on severity of sodium problems; for shale-based spoils, acid treatment can best be combined with either sand mulching, sand top-dressing, or sand incorporation. Gypsum plus phosphorus treatment in combination with sand top-dressing may provide an alternative treatment. 9 references.

  9. Inoculum density of Glomus mosseae and growth of onion plants in unsterilized bituminous coal spoil

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.G.

    1988-01-01

    The effect of inoculum, density (number of vesicular-arbuscular mycorrhizal (VAM) propagules g/sup -1/ of inoculum) on the growth of onions (Allium cepa L.) infected by Glomus mosseae (Nicol and Gerd). Gerdemann and Trappe, Comb nov in unsterilized coal spoil containing indigenous VAM fungi, including G. mosseae, was investigated. The amount of onion roots converted to mycorrhizas by inoculant fungus, estimated by a gridline intersect method, increased with inoculum density (..gamma..0.62, P0.05) until a plateau was reached. Onion growth responses also increased significantly (P<0.05) with the amount of VAM inoculum present in the coal spoil. The initial linear relationship between inoculum propagules (MPN estimates), percent colonization of onion roots and onion shoot dry weight became quadratic as the number of infection propagules increased. VAM infection had no significant effect on root:shoot ratios. Similarly there was no significant interaction (P>0.05) between the inoculum density, VAM-colonized root mass and the onion root:shoot fresh weight ratios. The amount of the windswept bituminous coal spoil bound to VAM (presumably because of VAM external hyphae) also increased as inoculum density increased (..gamma..0.63, P<0.05). There was a stronger correlation (ga0.85, P<0.05) between the amount of spoil adhered per plant and the root fresh wt plant/sup -1/ indicating that root effects were primarily responsible for increasing spoil adherence. There were negative correlations (P<0.05) between root fresh wt plant/sup -1/ (..gamma..-0.68), inoculum density (..gamma..-0.589), percent root elngth infected (..gamma..-0.73) and the amount of spoil adhered g/sup -1/ root fresh wt. The possible exploitation of VAM in revegetation of bituminous coal spoil is discussed. 25 refs., 2 tabs.

  10. Spectral diffusion and electron-phonon coupling of the B800 BChl a molecules in LH2 complexes from three different species of purple bacteria.

    Science.gov (United States)

    Baier, J; Gabrielsen, M; Oellerich, S; Michel, H; van Heel, M; Cogdell, R J; Köhler, J

    2009-11-04

    We have investigated the spectral diffusion and the electron-phonon coupling of B800 bacteriochlorophyll a molecules in the peripheral light-harvesting complex LH2 for three different species of purple bacteria, Rhodobacter sphaeroides, Rhodospirillum molischianum, and Rhodopseudomonas acidophila. We come to the conclusion that B800 binding pockets for Rhodobacter sphaeroides and Rhodopseudomonas acidophila are rather similar with respect to the polarity of the protein environment but that the packaging of the alphabeta-polypeptides seems to be less tight in Rb. sphaeroides with respect to the other two species.

  11. Establishment of native species on amended and unamended coal mine spoil in central Queensland

    International Nuclear Information System (INIS)

    Bell, L.C.; Mulligan, D.R.; Orr, M.S.; Johnstone, P.

    1994-01-01

    At the Curragh open-cut coal mine in central Queensland, tree and shrub growth on amended and unamended spoil was assessed over a 5-year period. The most successful media in terms of seedling densities were bare spoil and spoil covered by a thin layer of coarse coal reject. Where soil was replaced, very few native species established due to the intense competition from exotic grasses. Given this poor establishment on soil, the question of how well an ecosystem would develop on non-soil media was addressed by assessing the ability of each of the media to support sustainable communities in the longer term. Early results from direct-seeding tree and shrub species onto non-soil media have been quite encouraging, but analysis of the surface horizons has shown that after several years, there are still some characteristics which could either limit the re-establishment, and/or prevent the sustainability, of new communities. Due primarily to the high sulfate levels originally in the coal reject, the surface salinity in these treatments was much higher than in the uncapped spoil. Substrate analyses have shown also that there was a much lower concentration of mineralizable N in the spoil and coal reject than in the soil, revealing that the potential of these non-soil substrates to continue supplying nitrogen to the system is greatly reduced. Furthermore, the concentration of microbial biomass carbon was significantly lower in these media, and the percentage ground cover after 5 years was generally <10%

  12. Effect of antioxidants on thiobarbituric acid reactive substances, psychrotrophic bacteria and functional properties of mechanically deboned chicken meat irradiated with Cobalto-60 and electron beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Pomarico Neto, Walter, E-mail: hgomes@cnen.gov.br, E-mail: pbrito@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: abrusqui@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Mourao, Gerson Barreto; Orlando, Eduardo Adilson; Miyagusku, Luciana, E-mail: marciamh@ital.sp.gov.br, E-mail: eduardo.orlando@ital.sp.gov.br [Instituto de Tecnologia dos Alimentos (ITAL), Campinas, SP (Brazil)

    2013-07-01

    Samples of MDCM with skin were divided into three groups: control (without antioxidants), Antioxidant 1 (Sodium Polyphosphate and Sodium Ascorbate and Antioxidant 2 (Rosemary Extract and α-Tocopherol. The three batches of samples were divided into nine groups: no antioxidant and non-irradiated (C), with antioxidant A1 and non-irradiated (A1), with antioxidant A2 and non-irradiated (A2) without antioxidant and irradiated in Cobalt-60 source (Co), with antioxidant A1 irradiated in Cobalt 60 source (A1Co) with antioxidant A2 irradiated in Cobalt-60 source (A2Co) with antioxidant A1 irradiated in Electron beam (A1Eb) and with antioxidant A2 irradiated in Electron beam (A2Eb). The samples was conditioned in a transparent, low density frozen overnight at a temperature of -18 ± 1 deg C in a chamber, and irradiated in this state with a dose of 3.0 kGy, used two sources of radiation: Cobalt-60 (3.1 kGy/h) and electron beam (7.86 kGy/s). After this process, the samples were evaluated during the refrigeration period (2 ± 1 deg C) for 11 days for the following analysis: total psychrotrophic bacteria count and thiobarbituric acid reactive substances (TBARS) and the analysis of functional properties were performed after the irradiation process. The use of the combination of rosemary antioxidant and α-tocopherol were able to significantly decrease TBARS values caused by the irradiation of samples in MDCM cobalt-60 sources and electron beam, and show a synergetic effect to processing with ionizing radiation to reduce of psychrotrophic bacteria count. The use of irradiation processing of MDCM did not negatively affect the functional properties studied. (author)

  13. Effect of antioxidants on thiobarbituric acid reactive substances, psychrotrophic bacteria and functional properties of mechanically deboned chicken meat irradiated with Cobalto-60 and electron beam sources

    International Nuclear Information System (INIS)

    Brito, Poliana de Paula; Azevedo, Heliana de; Roque, Claudio Vitor; Pomarico Neto, Walter

    2013-01-01

    Samples of MDCM with skin were divided into three groups: control (without antioxidants), Antioxidant 1 (Sodium Polyphosphate and Sodium Ascorbate and Antioxidant 2 (Rosemary Extract and α-Tocopherol. The three batches of samples were divided into nine groups: no antioxidant and non-irradiated (C), with antioxidant A1 and non-irradiated (A1), with antioxidant A2 and non-irradiated (A2) without antioxidant and irradiated in Cobalt-60 source (Co), with antioxidant A1 irradiated in Cobalt 60 source (A1Co) with antioxidant A2 irradiated in Cobalt-60 source (A2Co) with antioxidant A1 irradiated in Electron beam (A1Eb) and with antioxidant A2 irradiated in Electron beam (A2Eb). The samples was conditioned in a transparent, low density frozen overnight at a temperature of -18 ± 1 deg C in a chamber, and irradiated in this state with a dose of 3.0 kGy, used two sources of radiation: Cobalt-60 (3.1 kGy/h) and electron beam (7.86 kGy/s). After this process, the samples were evaluated during the refrigeration period (2 ± 1 deg C) for 11 days for the following analysis: total psychrotrophic bacteria count and thiobarbituric acid reactive substances (TBARS) and the analysis of functional properties were performed after the irradiation process. The use of the combination of rosemary antioxidant and α-tocopherol were able to significantly decrease TBARS values caused by the irradiation of samples in MDCM cobalt-60 sources and electron beam, and show a synergetic effect to processing with ionizing radiation to reduce of psychrotrophic bacteria count. The use of irradiation processing of MDCM did not negatively affect the functional properties studied. (author)

  14. Traditional method of fish treatment, microbial count and palatability studies on spoiled fish

    Directory of Open Access Journals (Sweden)

    Abd Aziz, N. A.

    2013-01-01

    Full Text Available Aims: To evaluate the microbial count and palatability acceptance of spoiled fish after treatment with traditionally used naturalsolution.Methodology and results: To compare microbial count of spoiled fish before and after treatment with natural solution practicedby local people in Malaysia, 10 g of spoiled fish was respectively rinsed with 100 mL of 0.1% of natural solution such as Averrhoabilimbi extract, rice rinsed water, rice vinegar, Citrus aurantifolia extract, salt, flour, and Tamarindus indica extract. Flesh of fishrinsed with rice vinegar was found to be able to reduce microbial count (CFU/mL = 0.37 X 107 more than 4.5 times whencompared to spoiled fish (CFU/mL=1.67x 107. Spoiled fish that was treated with rice vinegar was prepared into a cutlet and fried.The cutlet was subjected to palatability acceptance study by a group of residents in Palm Court Condominium, Brickfields, KualaLumpur. The palatability study from the Cronbach alpha shown that the taste have the reliability of 0.802, the aroma has thereliability of 0.888, colour with the reliability of 0.772, texture or mouth feel have reliability of 0.840 and physical structure of thecutlet is 0.829.Conclusion, significance and impact of study: Treatment of spoiled fish using rice vinegar as practice by local peopletraditionally shown a significant reduction in microbial count and the vinegar-treated fish could be developed into a product that issafe and acceptable by the consumer.

  15. Remediation of an acidic mine spoil: Miscanthus biochar and lime amendment affects metal availability, plant growth and soil enzymatic activity

    Science.gov (United States)

    Biochar is proposed as an amendment for mine spoil remediation; however, its effectiveness at achieving this goal remains unclear. Miscanthus (Miscanthus giganteus) biochar was tested for potentially improving acidic mine spoil (pH < 3; Formosa mine near Riddle, Oregon) health conditions by sequeste...

  16. Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method.

    Science.gov (United States)

    Shrestha, Kushal; Jakubikova, Elena

    2015-08-20

    Light-harvesting antennas are protein-pigment complexes that play a crucial role in natural photosynthesis. The antenna complexes absorb light and transfer energy to photosynthetic reaction centers where charge separation occurs. This work focuses on computational studies of the electronic structure of the pigment networks of light-harvesting complex I (LH1), LH1 with the reaction center (RC-LH1), and light-harvesting complex II (LH2) found in purple bacteria. As the pigment networks of LH1, RC-LH1, and LH2 contain thousands of atoms, conventional density functional theory (DFT) and ab initio calculations of these systems are not computationally feasible. Therefore, we utilize DFT in conjunction with the energy-based fragmentation with molecular orbitals method and a semiempirical approach employing the extended Hückel model Hamiltonian to determine the electronic properties of these pigment assemblies. Our calculations provide a deeper understanding of the electronic structure of natural light-harvesting complexes, especially their pigment networks, which could assist in rational design of artificial photosynthetic devices.

  17. Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria

    International Nuclear Information System (INIS)

    Dougal, R.A.

    1993-08-01

    High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a 60 Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of 60 Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 μg/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. 60 Co and electron beam irradiation were both lethal to the bacteria studied at irradiation levels far lower than were necessary to remove organic contaminants

  18. Growth strategy of heterotrophic bacterial population along successional sequence on spoil of brown coal colliery substrate

    Czech Academy of Sciences Publication Activity Database

    Krištůfek, Václav; Elhottová, Dana; Chroňáková, Alica; Dostálková, I.; Picek, T.; Kalčík, Jiří

    2005-01-01

    Roč. 50, č. 5 (2005), s. 427-435 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA526/03/1259 Institutional research plan: CEZ:AV0Z60660521 Keywords : growth strategy * heterotrophic bacterial population * brown coal colliery spoil Subject RIV: EH - Ecology, Behaviour Impact factor: 0.918, year: 2005

  19. Heavy metals in soil on spoil heap of an abandoned lead ore ...

    African Journals Online (AJOL)

    EJIRO

    (Ti, Fe and Al) of a soil profile on spoil heap were examined. 54 soil samples were .... move gravel and rocks, put in plastic bags then sent to the Service. Central du ..... micro- organisms and microbial processes in agricultural soils. A review.

  20. Forest-biological erosion control on coal-mine spoil banks in Bulgaria

    International Nuclear Information System (INIS)

    Haigh, M.J.; Gentcheva-Kostadinova, S.; Zheleva, E.

    1995-01-01

    The forest fallowing of coal-mine spoils helps re-establish the processes of natural, self-sustaining, soil formation. Environmental monitoring in Bulgaria demonstrates that forestation can moderate soil pH (from ph> 3.0 to pH 1.3 g/cm 3 in the 0-5 cm layer) in the case of coal briquette spoils at Pernik, near Sofia. Ground losses from forested, 16-17 degree slope, coal briquette-spoils at Pernik are a quarter of those from an entirely unvegetated section of the same embankment (48.5 vs 12. 1 mm in the period 1988-1994) despite the absence of ground cover beneath the trees. On lignite spoil banks, at Maritsa-Iztok, central Bulgaria, forestation increases the organic content of the soil to greater depths than revegetation with grass, and to a greater degree than conventional agricultural cultivation. On Pinus nigra forested crest sites at Pernik, and in Robinia pseudacacia forested groves on the lignite minespoil banks at Maritsa-Iztok, slopes showed ground advance rather than ground retreat. Slopes protected by mechanical means alone did not allow soil growth and, where the structure broke down, they suffered as much erosion as untreated sites. In sum, the forest fallowing of surface coal-mine disturbed land accelerates organic matter accumulation in the soil, helps improve soil structure, reduces erosion, and may transform soil loss into soil gain, even on steeply sloping sites. 17 refs., 3 figs., 1 tab

  1. 30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

    Science.gov (United States)

    2010-07-01

    ... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.72 Disposal of excess spoil: Valley fill/head-of-hollow fills.... Uncontrolled surface drainage may not be directed over the outslope of the fill. (2) Runoff from areas above the fill and runoff from the surface of the fill shall be diverted into stabilized diversion channels...

  2. In vivo quantitative NMR imaging of fruit tissues during growth using Spoiled Gradient Echo sequence

    DEFF Research Database (Denmark)

    Kenouche, S.; Perrier, M.; Bertin, N.

    2014-01-01

    of this study was to design a robust and accurate quantitative measurement method based on NMR imaging combined with contrast agent (CA) for mapping and quantifying water transport in growing cherry tomato fruits. A multiple flip-angle Spoiled Gradient Echo (SGE) imaging sequence was used to evaluate...

  3. 30 CFR 816.71 - Disposal of excess spoil: General requirements.

    Science.gov (United States)

    2010-07-01

    ... does not slake in water or degrade to soil material, and which is free of coal, clay or other... of the soil. (2) Excess spoil shall be transported and placed in a controlled manner in horizontal... outslope of the fill if required for stability, control of erosion, to conserve soil moisture, or to...

  4. 30 CFR 817.71 - Disposal of excess spoil: General requirements.

    Science.gov (United States)

    2010-07-01

    ... does not slake in water or degrade to soil materials, and which is free of coal, clay or other... of the soil. (2) Excess spoil shall be transported and placed in a controlled manner in horizontal... outslope of the fill if required for stability, control of erosion, to conserve soil moisture, or to...

  5. Earthworm succession in afforested colliery spoil heaps in the Sokolov region, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Pižl, Václav

    2001-01-01

    Roč. 9, č. 4 (2001), s. 359-364 ISSN 1061-2971 Institutional research plan: CEZ:AV0Z6066911 Keywords : earthworms * colliery spoil heaps * succession Subject RIV: EH - Ecology, Behaviour Impact factor: 1.011, year: 2001

  6. Raptor use of revegetated coal strip mine spoils in interior Alaska

    International Nuclear Information System (INIS)

    Elliott, C.L.

    1994-01-01

    Raptors associated with reclaimed coal strip mine spoils on the Usibelli Coal Mine in southcentral Alaska were observed in 1981 and 1982. Of the 10 raptor species identified on the mine, 6 (red-tailed hawk, golden eagle, Northern harrier, American kestrel, hawk owl, and short-eared owl) were observed hunting on the reclaimed areas

  7. Colonization of spoil benches of an opencast lignite mine in northwest Spain by amphibians and reptiles

    Energy Technology Data Exchange (ETDEWEB)

    Galan, P. [University of Santiago de Compostela, Santiago de Compostela (Spain). Faculty of Biology

    1997-02-01

    This paper discusses the colonization by reptiles and amphibians of the spoil benches of the Meirama opencast lignite mine in northwest Spain over 10 years, following the start of the revegetation process. At Meirama, spoil benches are initially fertilized and hydroseeded with a pasture mix, but are subject to little subsequent management and are gradually colonized by scrub vegetation characteristic of the region. Herpetofauna censuses were carried out yearly on a single 2 ha plot over 6 years following hydroseeding, and in a single year on ten 2 ha plots which had been hydroseeded between 0 and 10 years previously. In addition, censuses were carried out on three undisturbed `control` plots close to the mine. Fifteen species (nine amphibians and six reptiles) were detected in one or more of the spoil-bench plots. Recolonization was particularly rapid after the first 2-3 years post-hydroseeding, and was closely related to habitat development due to revegetation and natural succession. Species composition was most similar to that in control plots in the oldest (ten-year-old) spoil plots.

  8. Stabilization of metals in acidic mine spoil with amendments and red fescue (Festuca rubra L.) growth.

    Science.gov (United States)

    Simon, László

    2005-12-01

    Stabilization of metals with amendments and red fescue (Festuca rubra, cv. Keszthelyi 2) growth was studied on an acidic and phytotoxic mine spoil (pH(KCl) 3.20-3.26; Cd 7.1 mg kg(-1), Cu 120 mg kg(-1), Pb 2154 mg kg(-1) and Zn 605 mg kg(-1)) from Gyöngyösoroszi, Hungary in a pot experiment. Raising the pH above 5.0 by lime (CaCO(3)), and supplementing with 40 mg kg(-1)nitrogen (NH(4)NO(3)) made this material suitable for plant growth. All cultures were limed with 0.5% (m/m) CaCO(3) (treatment 1), which was combined with 5% (m/m) municipal sewage sludge compost (treatment 2), 5% (m/m) peat (treatment 3), 7.5% (m/m) natural zeolite (clinoptilolite) (treatment 4), and 0.5 (m/m) KH(2)PO(4) (treatment 5). Treatments 1-5 were combined with each other (treatment 6). After 60 days of red fescue growth, pH of the limed mine spoil decreased in all cultures units. Application of peat caused the highest pH decrease (1.15), while decrease of pH was less than 0.23 in treatments 2, 5 or 6. Application of lime significantly reduced concentrations of metals in the 'plant available' fraction of mine spoil compared to non-limed mine spoil. Amendments added to limed mine spoil changed variously the ratio of Cd, Cu, Pb and Zn in exchangeable or 'plant available' fractions, differently influencing the phytoavailability of these metals. Most of the metals were captured in the roots of test plants. Treatment 2 caused the appearance of less Cd in shoots (spoil, however the application of 0.5 phosphate was less favourable. Liming, application of amendments and growth of red fescue can stabilize metals in acidic and phytotoxic mine spoil, and by phytostabilization they can reduce the risk of metal contamination of the food chain.

  9. Survival and growth of wildlife shrubs and trees on acid mine spoil

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, D.K.; Adkisson, L.F.

    1980-01-01

    The purpose of this study was to assess the survival and growth of selected wildlife plants over a wide range of acid mine spoil conditions and to identify species suitable for surface mine reclamation. A major criterion in selection of study sites was inclusion of a wide range of spoil acidity conditions. The Ollis Creek (Study Area A) and Farrell (Study Area B) coal surface mines located in Campbell and Scott Counties, Tennessee, were selected for study. Seven plant species, all of which had been used in past reclamation demonstrations, were introduced on the 22 plots during March 1972. Autumn olive (Elaeagnus umbellata) was included as a control plant. Ten additional plant species were introduced during March 1973. With the exception of highbush blueberry (Vaccinium corymbosum var.). European filbert (Corylus avellana), and red maple (Acer rubrum), these species had not been used in TVA reclamation demonstrations. To assess the effects of spoil pH on the plants, the plots were grouped into seven pH categories, and mean percent survival and growth for each species were calculated. Results indicate that autumn olive, elaeagnus cherry, arnot locust, sawtooth oak, red maple, and Toringo crabapple are suitable for quick improvement of surface mine habitat over a wide range of spoil acidity in the Appalachian coalfield. Bessey cherry and European filbert need further study before a decision can be made regarding their reclamation utility. Species that are not recommended for quick habitat improvement over a wide range of surface mine spoil pH conditions include bush honeysuckle, barberry, Siberian crabapple, Manchu cherry, American beautyberry, bear oak, blueberry, rem-red honeysuckle, and redcedar.

  10. Dry flue gas desulfurization byproducts as amendments for reclamation of acid mine spoil

    International Nuclear Information System (INIS)

    Dick, W.A.; Stehouwer, R.C.; Beeghly, J.H.; Bigham, J.M.; Lal, R.

    1994-01-01

    Development of beneficial reuses of highly alkaline, dry flue gas desulfurization (FGD) byproducts can impact the economics of adopting these FGD technologies for retrofit on existing powerplants. Greenhouse studies were conducted to evaluate the use of two dry FGD byproducts for reclamation of acid mine spoil (pH, 3.1 to 5.8). Treatment rates of FGD ranges from 0% to 32% by dry weight and most treatments also included 6% by dry weight of sewage sludge. Fescue (Festuca arundinacea Schreb.) was harvested monthly for a total of six harvests. Plant tissue composition and root growth were determined after the sixth harvest. Leachate analyses and pH determination of mixes were done at the beginning and end of the experiments. Both FGD byproducts were effective in raising the spoil pH and in improving fescue growth. At the highest FGD application rate, fescue growth decreased from the optimum due to high pH and reduced rooting volume caused by cementation reactions between the FGD and spoil. Trace elements, with the exception of B, were decreased in the fescue tissue when FGD was applied. Leachate pH, electrical conductivity, dissolved organic carbon, Ca, Mg, and S tended to increase with increased FGD application rate; Al, Fe, Mn, and Zn decreased. pH was the most important variable controlling the concentrations of these elements in the leachate. Concentrations of elements of environmental concern were near or below drinking water standard levels. These results indicate that FGD applied at rates equivalent to spoil neutralization needs can aid in the revegetation of acid spoil revegetation with little potential for introduction of toxic elements into the leachate water or into the food chain

  11. A Ferredoxin- and F420H2-Dependent, Electron-Bifurcating, Heterodisulfide Reductase with Homologs in the Domains Bacteria and Archaea.

    Science.gov (United States)

    Yan, Zhen; Wang, Mingyu; Ferry, James G

    2017-02-07

    Heterodisulfide reductases (Hdr) of the HdrABC class are ancient enzymes and a component of the anaerobic core belonging to the prokaryotic common ancestor. The ancient origin is consistent with the widespread occurrence of genes encoding putative HdrABC homologs in metabolically diverse prokaryotes predicting diverse physiological functions; however, only one HdrABC has been characterized and that was from a narrow metabolic group of obligate CO 2 -reducing methanogenic anaerobes (methanogens) from the domain Archaea Here we report the biochemical characterization of an HdrABC homolog (HdrA2B2C2) from the acetate-utilizing methanogen Methanosarcina acetivorans with unusual properties structurally and functionally distinct from the only other HdrABC characterized. Homologs of the HdrA2B2C2 archetype are present in phylogenetically and metabolically diverse species from the domains Bacteria and Archaea The expression of the individual HdrA2, HdrB2, and HdrB2C2 enzymes in Escherichia coli, and reconstitution of an active HdrA2B2C2 complex, revealed an intersubunit electron transport pathway dependent on ferredoxin or coenzyme F 420 (F 420 H 2 ) as an electron donor. Remarkably, HdrA2B2C2 couples the previously unknown endergonic oxidation of F 420 H 2 and reduction of ferredoxin with the exergonic oxidation of F 420 H 2 and reduction of the heterodisulfide of coenzyme M and coenzyme B (CoMS-SCoB). The unique electron bifurcation predicts a role for HdrA2B2C2 in Fe(III)-dependent anaerobic methane oxidation (ANME) by M. acetivorans and uncultured species from ANME environments. HdrA2B2C2, ubiquitous in acetotrophic methanogens, was shown to participate in electron transfer during acetotrophic growth of M. acetivorans and proposed to be essential for growth in the environment when acetate is limiting. Discovery of the archetype HdrA2B2C2 heterodisulfide reductase with categorically unique properties extends the understanding of this ancient family beyond CO 2

  12. One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production: Progress report, February 1, 1987-February 1, 1988

    International Nuclear Information System (INIS)

    Zeikus, J.G.; Shen, Gwo-Jenn.

    1988-01-01

    These studies concern the fundamental biochemical mechanisms that control carbon and electron flow in anaerobic bacteria that conserve energy when coupling hydrogen consumption to the production of acetic, propionic, or butyric acids. Two acidogens, Propionispira arboris and Butyribacterium methylotrophicum were chosen as model systems to understand the function of oxidoreductases and electron carriers in the regulation of hydrogen metabolism and single carbon metabolism. In P. arboris, H 2 consumption was linked to the inhibition of CO 2 production and an increase in the propionate/acetate rate; whereas, H 2 consumption was linked to a stimulation of CO 2 consumption and an increase in the butyrate/acetate ratio in B. methylotrophicum. We report studies on the enzymes involved in the regulation of singe carbon metabolism, the enzyme activities and pathways responsible for conversion of multicarbon components to acetate and propionate or butyrate, and how low pH inhibits H 2 and acetic acid production in Sarcina ventriculi as a consequence of hydrogenase regulation. 9 refs

  13. Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors

    Science.gov (United States)

    Baesman, S.M.; Bullen, T.D.; Dewald, J.; Zhang, Dongxiao; Curran, S.; Islam, F.S.; Beveridge, T.J.; Oremland, R.S.

    2007-01-01

    Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [??] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods (???10-nm diameter by 200-nm length), which cluster together, forming larger (???1,000-nm) rosettes composed of numerous individual shards (???100-nm width by 1,000-nm length). In contrast, Sulfurospirillium barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  14. Beer spoilage bacteria and hop resistance.

    Science.gov (United States)

    Sakamoto, Kanta; Konings, Wil N

    2003-12-31

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

  15. The Occurrence of Beer Spoilage Lactic Acid Bacteria in Craft Beer Production.

    Science.gov (United States)

    Garofalo, Cristiana; Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Aquilanti, Lucia; Clementi, Francesca

    2015-12-01

    Beer is one of the world's most ancient and widely consumed fermented alcoholic beverages produced with water, malted cereal grains (generally barley and wheat), hops, and yeast. Beer is considered an unfavorable substrate of growth for many microorganisms, however, there are a limited number of bacteria and yeasts, which are capable of growth and may spoil beer especially if it is not pasteurized or sterile-filtered as craft beer. The aim of this research study was to track beer spoilage lactic acid bacteria (LAB) inside a brewery and during the craft beer production process. To that end, indoor air and work surface samples, collected in the brewery under study, together with commercial active dry yeasts, exhausted yeasts, yeast pellet (obtained after mature beer centrifugation), and spoiled beers were analyzed through culture-dependent methods and PCR-DGGE in order to identify the contaminant LAB species and the source of contamination. Lactobacillus brevis was detected in a spoiled beer and in a commercial active dry yeast. Other LAB species and bacteria ascribed to Staphylococcus sp., Enterobaceriaceae, and Acetobacter sp. were found in the brewery. In conclusion, the PCR-DGGE technique coupled with the culture-dependent method was found to be a useful tool for identifying the beer spoilage bacteria and the source of contamination. The analyses carried out on raw materials, by-products, final products, and the brewery were useful for implementing a sanitization plan to be adopted in the production plant. © 2015 Institute of Food Technologists®

  16. Remedial investigation report on Bear Creek Valley Operable Unit 2 (rust spoil area, spoil area 1, and SY-200 yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 2. Appendixes

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This document contains the appendices to the Remedial Investigation Report on Bear Creek Valley Operable Unit 2 (Rust Spoil Area, Spoil Area 1, and SY-200 Yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. The appendices include Current and historical soil boring and groundwater monitoring well information, well construction logs, and field change orders; Analytical data; Human health risk assessment data; and Data quality.

  17. Remedial investigation report on Bear Creek Valley Operable Unit 2 (rust spoil area, spoil area 1, and SY-200 yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 2. Appendixes

    International Nuclear Information System (INIS)

    1994-08-01

    This document contains the appendices to the Remedial Investigation Report on Bear Creek Valley Operable Unit 2 (Rust Spoil Area, Spoil Area 1, and SY-200 Yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. The appendices include Current and historical soil boring and groundwater monitoring well information, well construction logs, and field change orders; Analytical data; Human health risk assessment data; and Data quality

  18. Weathering processes under various moisture conditions in a lignite mine spoil from As Pontes (N.W. Spain)

    International Nuclear Information System (INIS)

    Seoane, S.; Leiros, M.C.

    1997-01-01

    Processes contributing to acid release/consumption during weathering of a lignite mine spoil (2.3% w/w S as sulfides) from As Pontes (N.W. Spain) were studied under three moisture conditions (at field capacity or under alternate wetting-drying or forced percolation), which were simulated in laboratory experiments. Oxidation of sulfides to sulfates was favoured under all three moisture conditions, releasing most acid in spoil kept at field capacity. Hydroxysulfates formed in spoil kept at field capacity or under alternate wetting-drying conditions, thereby contributing to acid release. Acid consumption by dissolution of clay minerals, especially micas, was favoured under all three moisture conditions, but was particularly intense in spoil at field capacity. Dissolution of aluminium oxides was also favoured under all the moisture conditions studied. 27 refs., 8 figs., 6 tabs

  19. The copper spoil heap Knappenberg, Austria, as a model for metal habitats – Vegetation, substrate and contamination

    Energy Technology Data Exchange (ETDEWEB)

    Adlassnig, Wolfram; Weiss, Yasmin S. [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); Sassmann, Stefan [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); University of Exeter, College of Life and Environmental Sciences, Biosciences, Stocker Road, Exeter EX4 4QD (United Kingdom); Steinhauser, Georg [Leibniz University Hannover, Institute of Radioecology and Radiation Protection, Herrenhäuser Straße 2, D30419 Hannover (Germany); Hofhansl, Florian [University of Vienna, Department of Microbiology and Ecosystem Science, Althanstraße 14, A-1090 Vienna (Austria); Instituto Nacional de Pesquisas da Amazônia, Coordenação de Dinâmica Ambiental, Manaus (Brazil); Baumann, Nils [Helmholtz-Zentrum Dresden-Rossendorf, Division of Biogeochemistry, Bautzner Landstraße 400, D-01328 Dresden (Germany); Lichtscheidl, Irene K. [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria); Lang, Ingeborg, E-mail: ingeborg.lang@univie.ac.at [University of Vienna, Core Facility Cell Imaging and Ultrastructure Research, Althanstraße 14, A-1090 Vienna (Austria)

    2016-09-01

    Historic mining in the Eastern Alps has left us with a legacy of numerous spoil heaps hosting specific, metal tolerant vegetation. Such habitats are characterized by elevated concentrations of toxic elements but also by high irradiation, a poorly developed substrate or extreme pH of the soil. This study investigates the distribution of vascular plants, mosses and lichens on a copper spoil heap on the ore bearing Knappenberg formed by Prebichl Layers and Werfener Schist in Lower Austria. It serves as a model for discriminating between various ecological traits and their effects on vegetation. Five distinct clusters were distinguished: (1) The bare, metal rich Central Spoil Heap was only colonised by highly resistant specialists. (2) The Northern and (3) Southern Peripheries contained less copper; the contrasting vegetation was best explained by the different microclimate. (4) A forest over acidic bedrock hosted a vegetation overlapping with the periphery of the spoil heap. (5) A forest over calcareous bedrock was similar to the spoil heap with regard to pH and humus content but hosted a vegetation differing strongly to all other habitats. Among the multiple toxic elements at the spoil heap, only Cu seems to exert a crucial influence on the vegetation pattern. Besides metal concentrations, irradiation, humidity, humus, pH and grain size distribution are important for the establishment of a metal tolerant vegetation. The difference between the species poor Northern and the diverse Southern Periphery can be explained by the microclimate rather than by the substrate. All plant species penetrating from the forest into the periphery of the spoil heap originate from the acidic but not from the calcareous bedrock. - Highlights: • Strong impact on plant diversity by isolation and extreme abiotic conditions • Both, microclimate and substrate explain species distribution. • Increased cellular metal tolerance of plants from the Central Spoil Heap • Among toxic elements

  20. Measurements of line overlap for resonant spoiling of x-ray lasing transitions

    International Nuclear Information System (INIS)

    Beiersdorfer, P.; Elliott, S.R.; MacGowan, B.J.; Nilsen, J.

    1994-06-01

    High-precision measurements are presented of candidate line pairs for resonant spoiling of x-ray lasing transitions in the nickel-like W 46+ , the neon-like Fe 16+ , and the neon-like La 47+ x-ray lasers. Our measurements were carried out with high-resolution crystal spectrometers, and a typical precision of 20--50 ppM was achieved. While most resonances appear insufficient for effective photo-spoiling, two resonance pairs are identified that provide a good overlap. These are the 4p 1/2 → 3d 3/2 transition in nickel-like W 46+ with the 2p 3/2 → 1s 1/2 transition in hydrogenic Al 12+ , and the 3s 1/2 → 2p 3/2 transition in neon-like La 47+ with the 1 1 S 0 -2 1 P 1 line in heliumlike Ti 20+

  1. The development of arbuscular mycorrhiza in two simulated stages of spoil-bank succession

    Czech Academy of Sciences Publication Activity Database

    Püschel, David; Rydlová, Jana; Vosátka, Miroslav

    2007-01-01

    Roč. 35, č. 2 (2007), s. 363-369 ISSN 0929-1393 R&D Projects: GA ČR GA526/04/0996; GA ČR(CZ) GD206/03/H137 Institutional research plan: CEZ:AV0Z60050516 Keywords : mycorrhiza * plant succession * spoil bank s Subject RIV: EF - Botanics Impact factor: 1.810, year: 2007

  2. Stillbirth and stigma: the spoiling and repair of multiple social identities

    OpenAIRE

    Brierley-Jones, L.; Crawley, R.; Lomax, S.; Ayers, S.

    2014-01-01

    This study investigated mothers' experiences surrounding stillbirth in the United Kingdom, their memory making and sharing opportunities, and the effect these opportunities had on them. Qualitative data were generated from free text responses to open-ended questions. Thematic content analysis revealed that "stigma" was experienced by most women and Goffman's (1963) work on stigma was subsequently used as an analytical framework. Results suggest that stillbirth can spoil the identities of "pat...

  3. Usefulness of enhanced breathhold 3D spoiled gradient-echo MRA for intrathoracic mass

    International Nuclear Information System (INIS)

    Kobayashi, Takeshi; Kadoya, Masumi; Kamimura, Ryoichi; Takashima, Tsutomu

    1999-01-01

    Enhanced Breathhold 3D Spoiled Gradient-echo MRA was very attractive method for not only evaluating relationship between intrathoracic mass and intrathoracic vessels, but also visualizing small pulmonary vessels that could not be detected conventional MRA methods. Moreover, this methods could be applied for evaluating vascularity of the lesions. This method will be accepted as routine pulse sequence for evaluating intrathoracic mass especially malignant tumors. (author)

  4. Cover layers to the growth of trees and shrobs over a sulfide spoil from gold mining

    Directory of Open Access Journals (Sweden)

    Igor Rodrigues de Assis

    2011-08-01

    Full Text Available This work was done at a gold mine company in Paracatu, MG, Brazil, and was conducted from March 2000 to November 2005. The substrate (spoil studied was a phillite rock which contains sulfides such as pyrite and arsenopyrite. This study aimed to evaluate the survival and growth of plant species on different combinations of substrate layers over the spoil. These layers were a cover layer and a sealing layer, both deposited over the spoil. The treatment 1 had saprolite (B1 in the sealing layer (SL and B1 with liming (B1L in the cover layer (CL. The treatment 2 had B1 in SL and B1L + soil with liming (SoL in the CL. The treatment 3 had B1 + SoL in the SL and B1L in the CL. The treatment 4 had B1 + SoL in the SL and B1L + SoL in the CL. The plant species used were Acacia farnesiana, A. holosericea, A. polyphylla, Albizia lebbeck, Clitoria fairchildiana, Flemingia sp., Mimosa artemisiana, M. bimucronata e Enterolobium contortisiliquum. Forty and 57 months after planting, collardiameter, height, and living plants were evaluated. The greatest survival rate was oobservedintreatmentwith B horizon of an Oxisoil in both layers, with 80 %. In general, M. bimucronata and A. farnesiana species showed the highest survival rate. The arsenic-content by Mehlich 3 in the cover layer ranged from 0.00 to 14.69 mg dm- 3 among treatments. The experimental results suggest that layers combinations above the sulfide substrate allow the rapid revegetation of the spoil.

  5. Erodibility of surface-mine spoil banks in southeastern Ohio : an approximation

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, C D; Studlick, J R.J.

    1979-07-01

    Measurements of accumulated sediment in inter-bank basins of unreclaimed strip mines determined the average annual site loss from unvegetated, 18-year-old spoil banks. Assuming that the universal soil loss equation (USLE) can be used to estimate sediment yield from strip mine slopes, the topographic factor in the USLE was determined in 2 ways, and values for erodibility well calculated. The technique is applicable to unreclaimed mines where inter-bank basins trap all slope-derived sediment.

  6. A Ferredoxin- and F420H2-Dependent, Electron-Bifurcating, Heterodisulfide Reductase with Homologs in the Domains Bacteria and Archaea

    Directory of Open Access Journals (Sweden)

    Zhen Yan

    2017-02-01

    Full Text Available Heterodisulfide reductases (Hdr of the HdrABC class are ancient enzymes and a component of the anaerobic core belonging to the prokaryotic common ancestor. The ancient origin is consistent with the widespread occurrence of genes encoding putative HdrABC homologs in metabolically diverse prokaryotes predicting diverse physiological functions; however, only one HdrABC has been characterized and that was from a narrow metabolic group of obligate CO2-reducing methanogenic anaerobes (methanogens from the domain Archaea. Here we report the biochemical characterization of an HdrABC homolog (HdrA2B2C2 from the acetate-utilizing methanogen Methanosarcina acetivorans with unusual properties structurally and functionally distinct from the only other HdrABC characterized. Homologs of the HdrA2B2C2 archetype are present in phylogenetically and metabolically diverse species from the domains Bacteria and Archaea. The expression of the individual HdrA2, HdrB2, and HdrB2C2 enzymes in Escherichia coli, and reconstitution of an active HdrA2B2C2 complex, revealed an intersubunit electron transport pathway dependent on ferredoxin or coenzyme F420 (F420H2 as an electron donor. Remarkably, HdrA2B2C2 couples the previously unknown endergonic oxidation of F420H2 and reduction of ferredoxin with the exergonic oxidation of F420H2 and reduction of the heterodisulfide of coenzyme M and coenzyme B (CoMS-SCoB. The unique electron bifurcation predicts a role for HdrA2B2C2 in Fe(III-dependent anaerobic methane oxidation (ANME by M. acetivorans and uncultured species from ANME environments. HdrA2B2C2, ubiquitous in acetotrophic methanogens, was shown to participate in electron transfer during acetotrophic growth of M. acetivorans and proposed to be essential for growth in the environment when acetate is limiting.

  7. Remediation of Acid Generating Colliery Spoil Using Steel Slag – Case Studies

    Directory of Open Access Journals (Sweden)

    Ghataora Gurmel S.

    2015-06-01

    Full Text Available One of the legacies of the coal mining industry is the existence of numerous colliery spoil mounds. Run-off waters from some of these mounds result in oxidation of sulphur compounds causing pH to drop to perhaps as low as 2.5. At this pH, mobility for metals increases and it results in destruction of both flora and fauna. In order to reduce acidity, a number of solutions have been investigated with varying degree of success. A recent study to reduce acidity in spoil run-off water included the use of Basic Oxygen Steel slag. Its slow release of lime resulted in longer term remediation compared with other techniques. In addition to this, steel slag contains elements which are essential for plant growth and can be regarded as a weak fertiliser. This was substantiated in two field trials, which had the aim of not only remediating acidity from two different types of colliery spoils, but also to develop a composition that supports grass growth. The objectives were achieved at both sites and some of the results of over 5000 chemical tests conducted during these studies are reported in this paper.

  8. Reclamation of acidic colliery spoil. III. Problems associated with the use of high rates of limestone

    Energy Technology Data Exchange (ETDEWEB)

    Costigan, P A [Univ. of Liverpool, England; Bradshaw, A D; Gemmell, R P

    1982-04-01

    Growth of Trifolium repens in acidic colliery spoil was suppressed by more than 90% when agricultural ground calcitic limestone was applied at above 5 t ha/sup -1/ whereas Lolium perenne was unaffected at rates up to 100 t ha/sup -1/. The inhibitory effect of ground limestone on T. repens was reduced by high phosphorus fertilization and disappeared within 34 weeks of treatment.There was some evidence that high liming caused an imbalance of the Ca/Mg ratio in freshly limed spoil, contribution to growth inhibition. Growth of L. perene was improved and the inhibitory effect on T. repens was alleviated by substituting magnesian limestone (dolomite) for calcitic limestone. Phosphate adsorption of spoil was similar after low and very high limestone applications but increased by 100% after liming at 25 t ha/sup -1/ to pH 5.1.It is suggested that phosphate adsorption at pH 5.1 is caused by freshly precipitated amorphous aluminium hydroxide. The practical implications of the results are discussed.

  9. The flow properties of colliery spoil rockpaste as used in the infilling of abandoned mine workings

    Energy Technology Data Exchange (ETDEWEB)

    Ghataora, G.S.; Jarvis, S.T. [University of Birmingham, Birmingham (United Kingdom)

    1998-07-01

    Colliery spoil is the major constituent of colliery spoil 'rockpaste' which has been used to infill abandoned limestone mines in the West Midlands of England since the early 1980s. The other constituents of rockpaste are pulverised fuel ash, lime and water. A key property of the rockpaste is its ability to flow within the mine workings over considerable distances before setting. This paper describes the work carried out to identify suitable sites as sources of colliery spoil for making rockpaste and goes on to consider the flow properties of the material and the monitoring methods used on-site. A full-scale trial comprising infilling a 6600 m{sup 3} section of an abandoned mine was conducted prior to the infilling of the Littleton Street Mine which had a volume of about 500 000 m{sup 3}. As well as describing the methods used for monitoring the movement of rockpaste material, a description is also given of a dip-meter developed specifically for the purpose of measuring the level of paste in the mine. The monitoring systems developed for use in the two case studies presented in this paper are now being used extensively for infilling other abandoned mine workings. 5 refs., 16 figs., 1 tab., 1 plate.

  10. Comparative genomic and plasmid analysis of beer-spoiling and non-beer-spoiling Lactobacillus brevis isolates.

    Science.gov (United States)

    Bergsveinson, Jordyn; Ziola, Barry

    2017-12-01

    Beer-spoilage-related lactic acid bacteria (BSR LAB) belong to multiple genera and species; however, beer-spoilage capacity is isolate-specific and partially acquired via horizontal gene transfer within the brewing environment. Thus, the extent to which genus-, species-, or environment- (i.e., brewery-) level genetic variability influences beer-spoilage phenotype is unknown. Publicly available Lactobacillus brevis genomes were analyzed via BlAst Diagnostic Gene findEr (BADGE) for BSR genes and assessed for pangenomic relationships. Also analyzed were functional coding capacities of plasmids of LAB inhabiting extreme niche environments. Considerable genetic variation was observed in L. brevis isolated from clinical samples, whereas 16 candidate genes distinguish BSR and non-BSR L. brevis genomes. These genes are related to nutrient scavenging of gluconate or pentoses, mannose, and metabolism of pectin. BSR L. brevis isolates also have higher average nucleotide identity and stronger pangenome association with one another, though isolation source (i.e., specific brewery) also appears to influence the plasmid coding capacity of BSR LAB. Finally, it is shown that niche-specific adaptation and phenotype are plasmid-encoded for both BSR and non-BSR LAB. The ultimate combination of plasmid-encoded genes dictates the ability of L. brevis to survive in the most extreme beer environment, namely, gassed (i.e., pressurized) beer.

  11. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    OpenAIRE

    Parada,José Luis; Caron,Carolina Ricoy; Medeiros,Adriane Bianchi P.; Soccol,Carlos Ricardo

    2007-01-01

    Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therap...

  12. Ecophysiology of the Anammox Bacteria

    NARCIS (Netherlands)

    Kartal, M.B.

    2008-01-01

    Anaerobic ammonium oxidizing (anammox) bacteria oxidize ammonium to dinitrogen gas with nitrite as the electron acceptor. These bacteria are the key players in the global nitrogen cycle, responsible for the most of nitrogen production in natural ecosystems. The anammox process is also a

  13. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  14. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  15. Magnetic Bacteria.

    Science.gov (United States)

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  16. Effects of coal spoil amendment on heavy metal accumulation and physiological aspects of ryegrass (Lolium perenne L.) growing in copper mine tailings.

    Science.gov (United States)

    Chu, Zhaoxia; Wang, Xingming; Wang, Yunmin; Liu, Guijian; Dong, Zhongbing; Lu, Xianwen; Chen, Guangzhou; Zha, Fugeng

    2017-12-21

    Copper mine tailings pose many threats to the surrounding environment and human health, and thus, their remediation is fundamental. Coal spoil is the waste by-product of coal mining and characterized by low levels of metals, high content of organic matter, and many essential microelements. This study was designed to evaluate the role of coal spoil on heavy uptake and physiological responses of Lolium perenne L. grown in copper mine tailings amended with coal spoil at rates of 0, 0.5, 1, 5, 10, and 20%. The results showed that applying coal spoil to copper mine tailings decreased the diethylenetriaminepentaacetic acid (DTPA)-extractable Cd, Cu, Pb, and Zn contents in tailings and reduced those metal contents in both roots and shoots of the plant. However, application of coal spoil increased the DTPA-extractable Cr concentration in tailings and also increased Cr uptake and accumulation by Lolium perenne L. The statistical analysis of physiological parameters indicated that chlorophyll and carotenoid increased at the lower amendments of coal spoil followed by a decrease compared to their respective controls. Protein content was enhanced at all the coal spoil amendments. When treated with coal spoil, the activities of superoxide dismutases (SOD), peroxidase (POD), and catalase (CAT) responded differently. CAT activity was inhibited, but POD activity was increased with increasing amendment ratio of coal spoil. SOD activity increased up to 1% coal spoil followed by a decrease. Overall, the addition of coal spoil decreased the oxidative stress in Lolium perenne L., reflected by the reduction in malondialdehyde (MDA) contents in the plant. It is concluded that coal spoil has the potential to stabilize most metals studied in copper mine tailings and ameliorate the harmful effects in Lolium perenne L. through changing the physiological attributes of the plant grown in copper mine tailings.

  17. Intensive care unit environmental surfaces are contaminated by multidrug-resistant bacteria in biofilms: combined results of conventional culture, pyrosequencing, scanning electron microscopy, and confocal laser microscopy.

    Science.gov (United States)

    Hu, H; Johani, K; Gosbell, I B; Jacombs, A S W; Almatroudi, A; Whiteley, G S; Deva, A K; Jensen, S; Vickery, K

    2015-09-01

    Hospital-associated infections cause considerable morbidity and mortality, and are expensive to treat. Organisms causing these infections can be sourced from the inanimate environment around a patient. Could the difficulty in eradicating these organisms from the environment be because they reside in dry surface biofilms? The intensive care unit (ICU) of a tertiary referral hospital was decommissioned and the opportunity to destructively sample clinical surfaces was taken in order to investigate whether multidrug-resistant organisms (MDROs) had survived the decommissioning process and whether they were present in biofilms. The ICU had two 'terminal cleans' with 500 ppm free chlorine solution; items from bedding, surrounds, and furnishings were then sampled with cutting implements. Sections were sonicated in tryptone soya broth and inoculated on to chromogenic plates to demonstrate MDROs, which were confirmed with the Vitek2 system. Genomic DNA was extracted directly from ICU samples, and subjected to polymerase chain reaction (PCR) for femA to detect Staphylococcus aureus and the microbiome by bacterial tag-encoded FLX amplicon pyrosequencing. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were performed on environmental samples. Multidrug-resistant bacteria were cultured from 52% (23/44) of samples cultured. S. aureus PCR was positive in 50%. Biofilm was demonstrated in 93% (41/44) of samples by CLSM and/or SEM. Pyrosequencing demonstrated that the biofilms were polymicrobial and contained species that had multidrug-resistant strains. Dry surface biofilms containing MDROs are found on ICU surfaces despite terminal cleaning with chlorine solution. How these arise and how they might be removed requires further study. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  18. Spoil pile instabilities with reference to a strip coal mine in Turkey: mechanisms and assessment of deformations

    Science.gov (United States)

    Kasmer, Ozgu; Ulusay, Resat; Gokceoglu, Candan

    2006-02-01

    With the increasing adoption of the surface mining of coal, problems associated with spoil pile instability, which affects resource recovery, mining cost, and safety and presents environmental hazards, have become a matter of prime concern to mine planners and operators. The study of geotechnical aspects is thus very important in the rational planning for the disposal, reclamation, treatment and utilization of spoil material. A strip coal mine, one of the largest open pit mines in Turkey, is located in Central Anatolia and provides coal to a thermal power station. Coal production is carried out in two adjacent open pits, the Central Pit and South Pit. A large-scale spoil pile instability over an area of 0.3 km2 occurred within the dumping area of the Central pit. In addition, small-scale movement occurred in the outside dumping area. This paper outlines the results of field and laboratory investigations to describe the mechanisms of the spoil pile instabilities and to assess deformations monitored over a long period following the failure. Shear test results indicate that the interface between the floor and spoil material dumped by dragline has a negligible cohesion and is the most critical plane of weakness for spoil pile instability. Back analyses based on the method of limit equilibrium and the numerical modelling technique, and observations in the pit revealed that failure occurred along a combined sliding surface consisting of a circular surface through the spoil material itself and a planar surface passing along the interface between the spoil piles and floor. The analyses also indicated that pore water pressure ratios of about 0.25 satisfy limiting equilibrium condition and that rainfall about one month before the failure may be a contributing factor to the instability. Movement monitoring data obtained following the failure over a 1.5-year period suggested that the ongoing deformations were mainly due to compaction of the spoil material. Based on the

  19. Antimicrobial activity of lactic acid bacteria and the spectrum of their biopeptides against spoiling germs in foods

    Directory of Open Access Journals (Sweden)

    Fatima Djadouni

    2012-06-01

    Full Text Available The objective of this study was to isolate LAB from dairy, meat products and agro-industrial wastes and to investigate their antagonist activity. A total of 141 isolates were screened for the inhibitory effect on ten indicator strains in the agar spot test. Results showed that strain LBbb0141 contained antimicrobial compound with wide spectrum that inhibited the growth of ten indicator Gram-positive and Gram-negative strains. The bacteriocin activity attained its maximum value using the MRS agar at initial pH 7.5 and 30°C incubation temperature.

  20. Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

    International Nuclear Information System (INIS)

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.

    1999-01-01

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist

  1. An assessment of processes for the manufacture of synthetic aggregates from colliery spoil

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, P J; Gartner, E M

    1980-09-01

    Following the laboratory development of a process for the manufacture of synthetic aggregates from colliery spoil for use in structural concrete, a technical and economic assessment of possible processing routes is reported. Rotary kilns, multi-hearth furnaces, sinter-strands, shaft kilns and fluidised bed furnaces are considered and capital and running costs for the various processes are estimated. It is concluded that the initial capital costs of plant are the main barrier to successful exploitation. The cost of fuel for sintering is over-shadowed by the costs of capital investment and electric power, so efforts to reduce fuel consumption are unlikely to make a process economic in themselves.

  2. Anthropogenic soils on spoil rock banks in North Bohemian Coal Basin, Czech Republic

    International Nuclear Information System (INIS)

    Raclavska, H.; Raclavsky, K.; Matysek, D.; Stalmachova, B.

    1997-01-01

    The area of the North Bohemian Coal Basin is devastated by the extensive exploitation of brown coal by open pit mining. Knowledge of newly formed soils, their properties, development and contamination is important from the point of view of biological regeneration of the landscape. The mineralogy of anthropogenic soils from the mining area is presented together with the geochemistry of nutrients and trace elements. Attention is paid to the soil-forming processes in the non-reclaimed spoil rock banks with the development of spontaneous vegetation. 3 refs., 1 fig., 4 tabs

  3. An appraisal of the potential use of fly ash for reclaiming coal mine spoil.

    Science.gov (United States)

    Ram, Lal C; Masto, Reginald E

    2010-01-01

    Growing dependence on coal-fired power plants for electrical generation in many countries presents ongoing environmental challenges. Burning pulverized coal in thermal power plants (TPPs) generates large amounts of fly ash (FA) that must be disposed of or otherwise handled, in an environmentally-sound manner. A possible option for dealing with fly ash is to use it as an amendment for mine spoil or other damaged soil. It has been demonstrated through studies in India and other countries that FA alone or in combination with organic or inorganic materials can be used in a productive manner for reclamation of mine spoil. The characteristics of FA, including silt-sized particles, lighter materials with low bulk density (BD), higher water holding capacity, favorable pH and significant concentrations of many essential plant nutrients, make it a potentially favorable amendment for mine spoil reclamation. Studies have indicated that the application of FA has improved the physical, chemical and biological qualities of soil to which it is applied. The release of trace metals and soluble salts from FA could be a major limitation to its application. This is particularly true of fresh, un-weathered FA or acidic FA, although perhaps not a concern for weathered/pond ash or alkaline FA. Some potential contaminants, especially metals and other salt ions, could be immobilized and rendered biologically inert by the addition of certain inorganic and organic amendments. However, in view of the variability in the characteristics of FAs that are associated with location, feed coal, combustion conditions and other factors, the suitability of a particular FA for a specific soil/mine spoil needs to be critically evaluated before it is applied in order to maximize favorable results and eliminate unexpected consequences. FA generated in India tends to be mostly alkaline, with lower levels of trace elements than are often found in FAs from other countries. The concentrations of potential

  4. Mine spoil prairies expand critical habitat for endangered and threatened amphibian and reptile species

    Science.gov (United States)

    Lannoo, Michael J.; Kinney, Vanessa C.; Heemeyer, Jennifer L.; Engbrecht, Nathan J.; Gallant, Alisa L.; Klaver, Robert W.

    2009-01-01

    Coal extraction has been occurring in the Midwestern United States for over a century. Despite the pre-mining history of the landscape as woodlands, spent surface coalfields are often reclaimed to grasslands. We assessed amphibian and reptile species on a large tract of coal spoil prairie and found 13 species of amphibians (nine frog and four salamander species) and 19 species of reptiles (one lizard, five turtle, and 13 snake species). Two state-endangered and three state species of special concern were documented. The amphibian diversity at our study site was comparable to the diversity found at a large restored prairie situated 175 km north, within the historic prairie peninsula.

  5. Biological reclamation of coal mine spoils without topsoil: an amendment study with domestic raw sewage and grass-legume mixture

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, S.K.; Saxena, N.C. [Indian School of Mines, Dhanbad (India). Centre of Mining Environment

    1997-12-31

    A range of tree species were successfully established and grown on spoil site irrigated with domestic raw sewage in India. The heavy metals content in leaves, stem wood, stem bark root wood and root bark differ between species. In general, heavy metals like Fe, Zn, Mn, Cu, and Pb were accumulated more in Eucalyptus then Melia, however only Co accumulated maximum in Acacia. Increase trend was reported in respect of Na, K, Fe, Zn, Cu in grass and vegetables which were grown at a sewage fed farm. However, in all the cases micronutrients and heavy metals contents did not reach the critical limits to produce any phytotoxic effect. Irrigation with raw sewage had no adverse effect on chemical properties of spoil over the 3 year period. This study shows that raising vegetation on spoil material in mining areas irrigated with raw sewage is feasible. However, irrigation by raw sewage caused the accumulation of heavy metals in different plant parts. These plants are not of the fodder type and thus are not entering directly into ecological food chains, hence they can act as heavy metals sinks. On the basis of the Grass-legume experimental study, it may be concluded that N accumulation of coal mine spoil related with nature of spoil, prevailing climate and legume used. In a tropical climate N accumulation rate was found higher than in a temperate one. Addition of phosphorus fertilizer is essential for the reclamation of many mine spoils because even after three years available P level can remain deficient. Available K was found to be sufficient after three years.

  6. Chemical composition of spoil from bituminous coal and anthracite in Spain. Composicion quimica de los esteriles de hulla y antracita de Espana

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Canibano, J; Fernandez Valcarce, A

    1991-05-01

    The article describes the chemical composition of spoil from bituminous coal and anthracite in Spain. Chemical composition, mineralogical properties and physical and mechanical characteristics are used to determine the most suitable application for the spoil in order to solve the problem of disposal. 20 refs., 5 figs., 4 tabs.

  7. Use of colliery spoil in public works. La utilizacion de esteriles de la mineria del carbon en obras publicas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Canibano, J.; Rodriguez Ortiz, J.M. (HUNOSA, Oviedo (Spain))

    Colliery spoil presents a number of problems with regard to its storage because of the high cost involved, the difficulty of finding suitable land and its integration into the landscape. These factors are also affected by environmental legislation. One of the most interesting applications for colliery dirt is in the field of public works for in-filling operations, embankments, road building, dikes, etc., applications which require huge quantities of material without it needing to be processed. This article describes the physical and mechanical properties of colliery spoil from the point of view of its use in public works. 14 refs., 17 figs., 3 tabs.

  8. Guide for calculating the stability of mine berms and spoil bank slopes in the Maritsa-Iztok coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, G; Todorova, M; Doneva, V; Novachkov, N; Nedyalkov, N; Mitev, A; Rachev, R

    1984-08-01

    Major landslides are described which occurred in the basin between 1963 and 1970 during overburden removal and formation of spoil banks. Guidelines for the prevention of landslides were developed on the basis of large scale studies of geomechanics, geostatic calculations and geodetic observations of slope behavior; no further landslide has occurred since 1970. Cohesion coefficients, angle of internal friction and shear properties were determined for each material occurring in the clayey and sandy overburden and for the coal (ash content 15-55%). Slope stability of working benches and spoil banks at the Troyanovo mines was then calculated. 8 references.

  9. Exact algebraization of the signal equation of spoiled gradient echo MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dathe, Henning [Department of Orthodontics, Biomechanics Group, University Medical Centre, Goettingen (Germany); Helms, Gunther, E-mail: ghelms@gwdg.d [MR-Research in Neurology and Psychiatry, University Medical Centre, Goettingen (Germany)

    2010-08-07

    The Ernst equation for Fourier transform nuclear magnetic resonance (MR) describes the spoiled steady-state signal created by periodic partial excitation. In MR imaging (MRI), it is commonly applied to spoiled gradient-echo acquisition in the steady state, created by a small flip angle {alpha} at a repetition time TR much shorter than the longitudinal relaxation time T{sub 1}. We describe two parameter transformations of {alpha} and TR/T{sub 1}, which render the Ernst equation as a low-order rational function. Computer algebra can be readily applied for analytically solving protocol optimization, as shown for the dual flip angle experiment. These transformations are based on the half-angle tangent substitution and its hyperbolic analogue. They are monotonic and approach identity for small {alpha} and small TR/T{sub 1} with a third-order error. Thus, the exact algebraization can be readily applied to fast gradient echo MRI to yield a rational approximation in {alpha} and TR/T{sub 1}. This reveals a fundamental relationship between the square of the flip angle and TR/T{sub 1} which characterizes the Ernst angle, constant degree of T{sub 1}-weighting and the influence of the local radio-frequency field.

  10. Work plan, health and safety plan, and site characterization for the Rust Spoil Area (D-106)

    International Nuclear Information System (INIS)

    Bohrman, D.E.; Uziel, M.S.; Landguth, D.C.; Hawthorne, S.W.

    1990-06-01

    As part of the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) of the Department of Energy's Y-12 Plant located in Oak Ridge, Tennessee, this work plan has been developed for the Rust Spoil Area (a solid waste disposal area). The work plan was developed by the Measurement Applications and Development Group (MAD) of the Health and Safety Research Division (HASRD) at Oak Ridge National Laboratory (ORNL) and will be implemented jointly by ORNL/MAD and the Y-12 Environmental Surveillance Section. This plan consists of four major sections: (1) a project description giving the scope and objectives of the investigation at the Rust Spoil Area; (2) field and sampling procedures describing sample documentation, soil sampling techniques, sample packaging and preservation, equipment decontamination, and disposal of investigation generated wastes; (3) sample analysis procedures detailing necessary analytical laboratory procedures to ensure the quality of chemical results from sample receipt through analysis and data reporting; and (4) a health and safety plan which describes general site hazards and particular hazards associated with specific tasks, assigns responsibilities, establishes personnel protection standards and mandatory safety procedures, and provides emergency information for contingencies that may arise during the course of field operations

  11. Biochar addition induced the same plant responses as elevated CO2 in mine spoil.

    Science.gov (United States)

    Zhang, Yaling; Drigo, Barbara; Bai, Shahla Hosseini; Menke, Carl; Zhang, Manyun; Xu, Zhihong

    2018-01-01

    Nitrogen (N) limitation is one of the major constrain factors for biochar in improving plant growth, the same for elevated atmospheric carbon dioxide (CO 2 ). Hence, we hypothesized that (1) biochar would induce the same plant responses as elevated CO 2 under N-poor conditions; (2) elevated CO 2 would decrease the potential of biochar application in improving plant growth. To test these hypotheses, we assessed the effects of pinewood biochar, produced at three pyrolytic temperatures (650, 750 and 850 °C), on C and N allocation at the whole-plant level of three plant species (Austrostipa ramossissima, Dichelachne micrantha and Isolepis nodosa) grown in the N poor mine spoil under both ambient (400 μL L -1 ) and elevated (700 μL L -1 ) CO 2 concentrations. Our data showed that biochar addition (1) significantly decreased leaf total N and δ 15 N (P < 0.05); (2) decreased leaf total N and δ 15 N more pronouncedly than those of root; and (3) showed more pronounced effects on improving plant biomass under ambient CO 2 than under elevated CO 2 concentration. Hence, it remained a strong possibility that biochar addition induced the same plant physiological responses as elevated CO 2 in the N-deficient mine spoil. As expected, elevated CO 2 decreased the ability of biochar addition in improving plant growth.

  12. PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

    Science.gov (United States)

    Prevost, S; Andre, S; Remize, F

    2010-12-01

    Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

  13. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  14. Efficacy of Designer Biochars with or without Lime Application for Remediating Heavy Metals in Mine Spoil Soils

    Science.gov (United States)

    Sigua, Gilbert C.; Novak, Jeffrey; Johnson, Mark; Ippolito, James; Spokas, Kurt; Ducey, Thomas; Trippe, Kristin

    2017-04-01

    A multitude of research investigations have confirmed that biochars can increase soil carbon sequestration, improve critical plant nutrient concentrations, and improve the fertility, chemical, and physical properties of degraded agricultural soils. Recently, biochars ability to sequester metals has caught the attention of the mine reclamation sector. It is proposed that biochar is a suitable amendment to remediate heavy metals in mine spoils, as well as improve chemical conditions for enhanced plant growth. Better plant growth will improve phytostabilization, increase containment of metal-laden sediment, while also reducing potential metal uptake by plants. As such, utilization of a biochar with appropriate chemical and physical characteristics is crucial for effective binding of heavy metals while also improving plant growth conditions in mine spoils. Using two different mine spoils, we conducted laboratory and greenhouse experiments to determine the ability of designer biochar with or without lime application to favorably improve soil pH, reduce heavy metal bioavailability, and improve grass (e.g., wild blue rye) plant nutrient uptake. Preliminary results showed that our designer biochars did increase pH of acid mine spoils significantly (pheavy metals (e.g. aluminum, chromium, zinc, nickel, zinc, manganese, copper and cadmium) in the soils.

  15. Remediation of an acidic mine spoil: Miscanthus biochar and lime amendment affects metal availability, plant growth, and soil enzyme activity.

    Science.gov (United States)

    Novak, Jeffrey M; Ippolito, James A; Ducey, Thomas F; Watts, Donald W; Spokas, Kurt A; Trippe, Kristin M; Sigua, Gilbert C; Johnson, Mark G

    2018-08-01

    Biochar may be a tool for mine spoil remediation; however, its mechanisms for achieving this goal remain unclear. In this study, Miscanthus (Miscanthus giganteus) biochar was evaluated for its ability to reclaim acidic mine spoils (pH lime/no lime and fertilizer additions. Blue Wildrye (Elymus glaucus cv. 'Elkton') was planted and later the shoots and roots were collected and metal concentrations determined. Afterwards, each pot was leached with deionized water, and the leachate analyzed for pH, electrical conductivity (EC), dissolved organic carbon (DOC) and soluble metal concentrations. After drying, the spoil was extracted with 0.01 M CaCl 2 and Mehlich 3 (M3) to determine extractable Al, Cu, and Zn concentrations. Additionally, microbial activity was measured using a fluorescent β-glucosidase and N-acetyl-β-d-glucosaminidase assay. Spoil treated with lime and biochar had significantly greater pH and EC values. Significantly greater β-glucosidase activity occurred only in the 5% biochar plus lime treatment, while N-acetyl-β-d-glucosaminidase activities were not altered. Metal concentrations in rye shoot and roots were mixed. Lime additions significantly reduced extractable metal concentrations. Increasing biochar rates alone significantly reduced leachate DOC concentrations, and subsequently reduced leachable metal concentrations. Surprisingly, miscanthus biochar, by itself, was limited at mitigation, but when combined with lime, the combination was capable of further reducing extractable metal concentrations and improving β-glucosidase enzyme activity. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Effect of biotic and abiotic factors on soil microbial community diversity during primary succession on colliery spoil heaps

    Czech Academy of Sciences Publication Activity Database

    Elhottová, Dana; Frouz, Jan; Chroňáková, Alica; Malý, S.; Krištůfek, Václav; Kalčík, Jiří; Szili-Kovács, T.; Picek, T.

    2004-01-01

    Roč. 45, - (2004), s. 51 ISSN 0009-0646. [Kongres československé společnosti mikrobiologické /23./. 06.09.2004-09.09.2004, Brno] Keywords : soil microbial community * primary succession * colliery spoil heaps Subject RIV: EH - Ecology, Behaviour

  17. Colonization of colliery spoil heaps by millipedes (Diplopoda) and terrestrial isopods (Oniscidea) in the Sokolov region, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Tajovský, Karel

    2001-01-01

    Roč. 9, č. 4 (2001), s. 365-369 ISSN 1061-2971 Institutional research plan: CEZ:AV0Z6066911 Keywords : colliery spoil heaps * succession * rekultivation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.011, year: 2001

  18. Associations of dominant plant species with arbuscular mycorrhizal fungi during vegetation development on coal mine spoil banks

    Energy Technology Data Exchange (ETDEWEB)

    Rydlova, J.; Vosatka, M. [Academy of Science. Pruhonice (Czech Republic). Inst. of Botany

    2001-07-01

    Among plants colonizing mine spoil banks in Northern Bohemia the first colonizers, mainly ruderal annuals from Chenopodiaceae and Brassicaceae were found not to be associated with arbuscular mycorrhizal fungi (AMF). These species cultivated in pots with soil from four sites in different succession stages of the spoil bank did not respond to the presence of native or non-native AMF. All grass species studied (Elytrigia repens, Calamagrostis epigejos and Arrhenatherum elatius) were found moderately colonized in the field. Carduus acanthoides was found to be highly colonized in the field; however, it did not show growth response to AMF in the pot experiment. The AMF native in four sites on the spoil banks showed high infectivity but low effectiveness in association with colonizing plants compared to the non-native isolate G. fistulosum BEG23. In general, dependence on AMF in the cultivation experiment was rather low, regardless of the fact that plants were found to be associated with AMF either in the field or in pots. Occurrence and effectiveness of mycorrhizal associations might relate primarily to the mycotrophic status of each plant species rather than to the age of the spoil bank sites studied.

  19. Spoiling of radiation zeros at the one-loop level and infrared finiteness

    International Nuclear Information System (INIS)

    Laursen, M.L.; Samuel, M.A.; Sen, A.

    1983-01-01

    We consider the amplitude for the radiative decay W - →phi 1 phi 2 #betta# (scalar quarks) including one-loop gluon corrections. We study this process to see if the amplitude (radiation) zeros found in lowest order survive at the one-loop level. The subset of diagrams containing self-mass insertions preserves the zero. Seagull types are shown to have a violation which is similar to kappanot =1. Triangle and box diagrams spoil the zeros as they do in the case of a scalar W. However, the amplitude is completely free of any mass singularities in the classical null zone. We conjecture that this will remain true for spin-(1/2) quarks

  20. Stillbirth and stigma: the spoiling and repair of multiple social identities.

    Science.gov (United States)

    Brierley-Jones, Lyn; Crawley, Rosalind; Lomax, Samantha; Ayers, Susan

    This study investigated mothers' experiences surrounding stillbirth in the United Kingdom, their memory making and sharing opportunities, and the effect these opportunities had on them. Qualitative data were generated from free text responses to open-ended questions. Thematic content analysis revealed that "stigma" was experienced by most women and Goffman's (1963) work on stigma was subsequently used as an analytical framework. Results suggest that stillbirth can spoil the identities of "patient," "mother," and "full citizen." Stigma was reported as arising from interactions with professionals, family, friends, work colleagues, and even casual acquaintances. Stillbirth produces common learning experiences often requiring "identity work" (Murphy, 2012). Memory making and sharing may be important in this work and further research is needed. Stigma can reduce the memory sharing opportunities for women after stillbirth and this may explain some of the differential mental health effects of memory making after stillbirth that is documented in the literature.

  1. Plant growth inhibition by soluble salts in sewage sludge-amended mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, C.S.; Anderson, R.C. [Illinois State University, Normal, IL (United States). Dept. of Biological Sciences

    1995-07-01

    The growth response of prairie switchgrass {ital Panicum virgatum}L was compared in strip mine spoil amended with various levels of anaerobically digested waste-activated sewage sludge (0, 56, 111, 222, or 333 dry Mg ha{sup -1}) and commercial fertilizer, pure sludge, and glasshouse soil. Plants were grown in a growth chamber and substrates were maintained at field capacity during the study. Soluble salt concentrations of the substrates increased linearly as a function of sludge amendment and were within the range known to inhibit the growth of many plant species at the high levels of sludge application. There was, however, a linear response of biomass production to increasing levels of sludge amendment. Maintaining substrates at field capacity apparently prevented the high concentration of soluble salts from inhibiting plant growth. The increased biomass yield associated with sludge application was likely due to the increased availability of inorganic nutrients associated with sludge amendment. 22 refs., 2 figs., 2 tabs.

  2. Selenium transformation in coal mine spoils: Its environmental impact assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harness, J.; Atalay, A.; Koll, K.J.; Zhang, H.; Maggon, D.

    1991-12-31

    The objective of this program was to conduct an environmental impact assessment study for selenium from coal mine spoils. The use of in-situ lysimetry to predict selenium speciation, transformation, and mobility under natural conditions was evaluated. The scope of the study was to construct and test field-scale lysimeter and laboratory mini-column to assess mobility and speciation of selenium in coal mine overburden and soil systems; to conduct soil and groundwater sampling throughout the state of Oklahoma for an overall environmental impact assessment of selenium; and to conduct an in-depth literature review on the solubility, speciation, mobility, and toxicity of selenium from various sources. Groundwater and surface soil samples were also collected from each county in Oklahoma. Data collected from the lysimeter study indicated that selenium in the overburden of the abandoned mine site was mainly found in the selenite form. The amount of selenite found was too low and immobile to be of concern to the environment. The spoil had equilibrated long enough (over 50 years) that most of the soluble forms of selenium have already been lost. Examination of the overburden indicated the presence of pyrite crystals that precipitated over time. The laboratory mini-column study indicated that selenite is quite immobile and remained on the overburden material even after leaching with dilute acid. Data from groundwater samples indicated that based on the current permissible level for selenium in groundwater (0.01 mg Se/L), Oklahoma groundwater is widely contaminated with the element. However, according to the new regulation (0.05 mg Se/L), which is to be promulgated in 1992, only 9 of the 77 counties in the state exceed the limit.

  3. Rumen bacteria

    International Nuclear Information System (INIS)

    McSweeney, C.S.; Denman, S.E.; Mackie, R.I.

    2005-01-01

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 10 11 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (10 4 -10 6 /g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 10 2 -10 4 /g distributed over 5 genera). The occurrence of bacteriophage is well documented (10 7 -10 9 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  4. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  5. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

  6. Hydrological remedial actions for polluted overburden dumps, spoils and landfills. Papers and posters; Wasserwirtschaftliche Sanierung von Bergbaukippen, Halden und Deponien. Vortraege und Posterbeitraege

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, A. [ed.; Haefner, F.; Schmidt, J.; Merkel, B. [comps.

    2000-07-01

    This publication contains the papers and posters presented at the conference 'Hydrological remedial actions for polluted overburden dumps, spoils and landfills. 35 Papers have been recorded as separate citations in this database.

  7. Assessment of the Influence of Dredge Spoil Dumping on the Seafloor Geological Integrity

    Directory of Open Access Journals (Sweden)

    Joonas J. Virtasalo

    2018-04-01

    Full Text Available The European Marine Strategy Framework Directive requires the development of suitable indicators for regular reporting on the environmental state and achievement of a good environmental status of EU's marine waters by 2020. The development of indicators for determining seafloor integrity and its possible disturbance by human activities have so far largely ignored the geological properties of seafloor. This paper presents a study of Vuosaari and Uusikaupunki-D offshore dumping sites in Finland, the northern Baltic Sea. Full coverage multibeam bathymetry and relative backscatter data, and a number of sediment cores were collected over the sites. The areas covered by dumped dredge spoil stand out in the multibeam images because of their irregular surface and elevated backscatter. The short gravity cores were studied for lithology, and in 1-cm slices for 137Cs activity, organic content, and grain size distribution. The dumped material is represented in the cores by the gravelly mud lithofacies with massive texture and angular coarse particles. The dumped material is coarser, less sorted and has higher kurtosis compared to natural sediment due to the admixing of blasted rock during the dredging activities, and limited sorting during fall through the water column upon dumping. Dispersed dredge spoil, which was suspended in the water column during the dumping activities or reworked from the dumped material mounds and redistributed along the seafloor soon thereafter, was deposited over a wide area as a thin layer that is not necessarily readily identifiable by visual inspection in the cores. Cesium activity helped distinguish the dumped material from the 137Cs-enriched natural sediments deposited after the 1986 Chernobyl disaster. Considering that the dumped material at many of the coring sites in the Vuosaari dumping area is covered by natural sediment, it probably is largely stable. In contrast, dumped material at the shallower Uusikaupunki-D site has

  8. Do Attitudes About Spoiling Children Affect Attitudes Regarding What Infants Need for Early Social-Emotional Development

    OpenAIRE

    Westover, Kathleen

    2012-01-01

    Secure infant attachment is important for the positive social-emotional development of children. Many parents have limited understanding of social-emotional development and the influence of appropriate responsive parenting behaviors to their infants’ cues. For example, many parents believe you can spoil an infant if you pick them up every time they cry. Researchers study the impact of positive responses to infants’ cues. Infants form a more secure attachment and learn to interpret the world a...

  9. Characterization of (per)chlorate-reducing bacteria

    NARCIS (Netherlands)

    Wolterink, A.F.W.M.

    2004-01-01

    Some bacteria can use (per)chlorateas terminal electron acceptor for growth. These bacteria convert perchlorate via chlorate and chlorite into chloride and molecular oxygen. Oxygen formation in microbial respiration is unique. In this study two chlorate-reducing strains

  10. Assessment of biochar and iron filing amendments for the remediation of a metal, arsenic and phenanthrene co-contaminated spoil

    International Nuclear Information System (INIS)

    Sneath, Helen E.; Hutchings, Tony R.; Leij, Frans A.A.M. de

    2013-01-01

    Sites contaminated with mixtures of metals, metalloids and organics are difficult to remediate as each contaminant type may require a different treatment. Biochar, with high metal sorption capacity, used singly and in combination with iron filings, is investigated in microcosm trials to immobilise metal(loid)s within a contaminated spoil, thereby enabling revegetation and degradation of organic pollutants. A mine spoil, contaminated with heavy metals, arsenic and spiked with phenanthrene was treated with either 1%w/w biochar, 5%w/w iron or their combination, enhancing phenanthrene degradation by 44–65%. Biochar treatment reduced Cu leaching and enabled sunflower growth, but had no significant effect on As mobility. Iron treatment reduced Cu and As leaching but negatively impacted soil structure and released high levels of Fe causing sunflower plant mortality. The combined treatment reduced both Cu and As leaching and enabled sunflower growth suggesting this could be a useful approach for treating co-contaminated sites. -- Highlights: ► 56 day microcosm trials examine biochar for remediation of co-contaminated sites. ► Biochar reduces leachable Cu concentrations but phytotoxicity remains. ► Iron filings are investigated as a co-amendment with biochar to reduce As leaching. ► Removal of metal toxicity stimulates phenanthrene degradation. ► Biochar could enable revegetation of contaminated sites. -- Biochar and iron filings incorporated into contaminated spoils reduce Cu and As leaching and stimulate phenanthrene degradation, but do not prevent phytotoxicity to sunflowers

  11. Thermal inactivation of polyphenoloxidase and peroxidase in Jubileu clingstone peach and yeast isolated from its spoiled puree

    Directory of Open Access Journals (Sweden)

    Andréa Menezes Lopes

    2014-03-01

    Full Text Available The thermal inactivation of yeast isolated from spoiled Jubileu peach puree and that of polyphenoloxidase (PPO and peroxidase (POD in cv. Jubileu, which is widely cultivated in southern Rio Grande do Sul state, Brazil, were studied. PPO and POD were extracted using the protein powder method and submitted to partial purification by precipitation followed by dialysis. The enzymatic activity was determined measuring the increase in absorbance at 420 nm for PPO and 470 nm for POD. The yeast used in this investigation was isolated from spoiled Jubileu peach puree at 22 °Brix, with total initial microbial count of 22 × 10² UFCmL- 1. Stock cultures were maintained on potato dextrose agar (PDA slants at 4 °C and pH 5 for later use for microbial growth. In all cases, kinetic analysis of the results suggests that the thermal inactivation was well described by a first-order kinetic model, and the temperature dependence was significantly represented by the Arrhenius law. Both enzymes were affected by heat denaturation, and PPO was more thermostable. PPO was also more thermosTable than the yeast isolated from peach puree. The D60-values were 1.53 and 1.87 min for PPO and yeast isolated from spoiled Jubileu peach puree, respectively.

  12. Response surface optimization of biosurfactant produced by Pseudomonas aeruginosa MA01 isolated from spoiled apples.

    Science.gov (United States)

    Abbasi, Habib; Sharafi, Hakimeh; Alidost, Leila; Bodagh, Atefe; Zahiri, Hossein Shahbani; Noghabi, Kambiz Akbari

    2013-01-01

    A potent biosurfactant-producing bacterial strain isolated from spoiled apples was identified by 16S rRNA as Pseudomonas aeruginosa MA01. Compositional analysis revealed that the extracted biosurfactant was composed of high percentages of lipid (66%, w/w) and carbohydrate (32%, w/w). The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mN m(-1) with critical micelle concentration (CMC) value of 10.1 mg L(-1). The Fourier transform infrared spectrum of extracted biosurfactant confirmed the glycolipid nature of this natural product. Response surface methodology (RSM) was employed to optimize the biosynthesis medium for the production of MA01 biosurfactant. Nineteen carbon sources and 11 nitrogen sources were examined, with soybean oil and sodium nitrate being the most effective carbon and nitrogen sources on biosurfactant production, respectively. Among the organic nitrogen sources examined, yeast extract was necessary as a complementary nitrogen source for high production yield. Biosurfactant production at the optimum value of fermentation processing factor (15.68 g/L) was 29.5% higher than the biosurfactant concentration obtained before the RSM optimization (12.1 g/L). A central composite design algorithm was used to optimize the levels of key medium components, and it was concluded that two stages of optimization using RSM could increase biosurfactant production by 1.46 times, as compared to the values obtained before optimization.

  13. Identifying yeast isolated from spoiled peach puree and assessment of its batch culture for invertase production

    Directory of Open Access Journals (Sweden)

    Marcela Vega FERREIRA

    Full Text Available Abstract The identification of yeasts isolated from spoiled Jubileu peach puree using the API 20C AUX method and a commercial yeast as witness were studied. Subsequently, the yeast’s growth potential using two batch culture treatments were performed to evaluate number of colonies (N, reducing sugar concentration (RS, free-invertase (FI, and culture-invertase activity (CI. Stock cultures were maintained on potato dextrose agar (PDA slants at 4 °C and pH 5 for later use for batch-culture (150 rpm at 30°C for 24 h, then they were stored at 4 °C for subsequent invertase extraction. The FI extract was obtained using NaHCO3 as autolysis agent, and CI activity was determined on the supernatant after batch-cultured centrifugation. The activity was followed by an increase in absorbance at 490 nm using the acid 3,5-DNS method with glucose standard. Of the four yeasts identified, Saccharomyces cerevisiae was chosen for legal reasons. It showed logarithmic growth up to 18 h of fermentation with positive correlation CI activity and inverse with RS. FI showed greater activity by the end of the log phase and an inverse correlation with CI activity. Finally, it was concluded that treatment “A” is more effective than “B” to produce invertase (EC 3.2.1.26.

  14. Topography of Spoil Heaps and Its Role in Plant Succession and Soil Fauna Presence

    Directory of Open Access Journals (Sweden)

    Walmsley A.

    2017-03-01

    Full Text Available The spoil heaps from brown coal mining without technical reclamation are interesting specific sites for ecological relationships observation. This research was aimed at investigating whether topographic features, which determine soil nutrient and moisture distribution, in combination with soil fauna (wireworm and earthworm presence, affect plant community composition at a spontaneously revegetated post mining area with an undulating surface. Two sites of different age with three types of topographic features were selected, soil moisture and nutrient contents were measured, and plant community composition and soil macrofauna community were sampled at each position. Wireworms were present at all positions and were most abundant at the bottoms of waves at the younger site; their presence was correlated with the presence of several plant species with high palatability for wireworms, but the direction of the interaction is not clear. Earthworms were only present at the older site and had the highest abundance at flat sections. Earthworm presence affected the amount of nitrogen in soil - the highest nitrogen content was at the site with the highest earthworm density and was followed by a higher diversity of plant community. The plant community composition was generally correlated with plant available nutrient content - especially P and N. We infer that topographic features affect nutrient and soil fauna distribution, which consequently influences the plant community composition.

  15. Perspective on China's one-child family policy: spoiled children? Questions and responses.

    Science.gov (United States)

    Wyner, N B

    1987-01-01

    China's 1-child policy has been effective in its objective of limiting population growth, yet the policy never has been imposed rigidly. For example, the policy is less restrictive in rural areas where 80% of the population live. It is argued the workers in the countryside need larger families for production. Between 1986-87, China's birthrate increased from 18/1000 - 21/1000, suggesting an easing of policy restrictions. Some population experts maintain that population increase is not a major problem as long as gross income figures continue to exceed the growth of population. Others indicate that a renewed emphasis on small families may be necessary. Some planners have observed developmental dynamics that have serious implications for traditional social and family values. 1 mental health expert has identified the "spoiled child syndrome," noting that the child in the 1- child family seems to be more dependent, less able to take care of himself/herself, more self-centered yet has a higher intelligence quotient. Parent training classes are now being developed.

  16. Vertical distribution and temperature relations of sheathing mycorrhizas of Betula spp. growing on coal spoil

    Energy Technology Data Exchange (ETDEWEB)

    Ingleby, K.; Last, F.T.; Mason, P.A.

    1985-10-01

    Naturally-occurring fine roots (<2 mm dia.) of Betula spp. were sampled to a depth of 30 cm at seven locations on each of two transects across a heap of coal spoil in parts subject to after-burn. In the top 20 cm of substrate, 87% of the root pieces occurred. Irrespective of depth, sheathing mycorrhizas were found on 83% of the roof pieces. While the percentages of Paxillus-type mycorrhizas decreased with soil depth, those of a Scleroderma-type significantly increased. Total numbers of mycorrhizas counted at the end-of-season were independent of substrate temperatures. However, numbers of Paxillus-type mycorrhizas were inversely related to both annual mean and spring substrate temperatures, whereas those of the Scleroderma- type were directly related. Vegetative cultures of Scleroderma citrinum grew on an agar medium at 30 C, whereas those of Paxillus involutus did not; at lower temperatures the two fungi responded similarly to temperature changes. The evidence suggests that the observed patterns of mycorrhizal development reflect the changing competitive abilities of Scleroderma and Paxillus and/or host influences at different temperatures in the range 8-16 C.

  17. Occurrence of vesicular-arbuscular mycorrhizae in mixed overburden mine spoils of Texas

    Energy Technology Data Exchange (ETDEWEB)

    Mott, J.B.; Zuberer, D.A.

    1987-07-01

    Presently in east Texas, lignite surface mines are reclaimed and revegetated using mixed overburden materials which are equivalent to or better in physical-chemical properties than the poor topsoils removed during mining. Little information is available regarding the biological characteristics of levelled mixed overburden and the re-establishment of endomycorrhizal associations on revegetated mixed overburden sites. Therefore, the authors investigated the occurrence of infection of coastal bermudagrass (Cynodon dactylon), planted vegetatively on reclamation sites (1-10 years post-mining), with vesicular-arbuscular mycorrhizal (VAM) fungi. Numbers of spores were also monitored. For comparison, infection of coastal bermudagrass and spore numbers were determined for an unmined old field succession on soil typical of the region. VAM infection, measured as a percentage of root length infected or as a percentage of root segments exhibiting infection, returned to pre-mining levels by 3-7 years after disturbance. Intensity of infection was not altered by disturbance, age of reclaimed site, or season. Significantly greater numbers of spores (ca. 10-fold) were observed in the unmined soil and no differences were found between numbers of spores from variously aged mine spoil sites. 35 refs., 3 tabs.

  18. Parameter Optimization for Quantitative Signal-Concentration Mapping Using Spoiled Gradient Echo MRI

    Directory of Open Access Journals (Sweden)

    Gasser Hathout

    2012-01-01

    Full Text Available Rationale and Objectives. Accurate signal to tracer concentration maps are critical to quantitative MRI. The purpose of this study was to evaluate and optimize spoiled gradient echo (SPGR MR sequences for the use of gadolinium (Gd-DTPA as a kinetic tracer. Methods. Water-gadolinium phantoms were constructed for a physiologic range of gadolinium concentrations. Observed and calculated SPGR signal to concentration curves were generated. Using a percentage error determination, optimal pulse parameters for signal to concentration mapping were obtained. Results. The accuracy of the SPGR equation is a function of the chosen MR pulse parameters, particularly the time to repetition (TR and the flip angle (FA. At all experimental values of TR, increasing FA decreases the ratio between observed and calculated signals. Conversely, for a constant FA, increasing TR increases this ratio. Using optimized pulse parameter sets, it is possible to achieve excellent accuracy (approximately 5% over a physiologic range of concentration tracer concentrations. Conclusion. Optimal pulse parameter sets exist and their use is essential for deriving accurate signal to concentration curves in quantitative MRI.

  19. Toxicity of laser irradiated photoactive fluoride PrF3 nanoparticles toward bacteria

    International Nuclear Information System (INIS)

    Pudovkin, M S; Korableva, S L; Krasheninnicova, A O; Nizamutdinov, A S; Semashko, V V; Zelenihin, P V; Alakshin, E M; Nevzorova, T A

    2014-01-01

    The article is devoted to exploration of biological effects of crystalline PrF 3 nanoparticles toward Salmonella typhimurium TA 98 bacteria under the laser irradiation. Obtained results show bactericidal activity of PrF 3 nanoparticles and optimal parameters of laser irradiation (power of laser irradiation, wavelength, diameter of the laser spoil, and exposure time) have been found under which the effects of bactericidal activity become the most significant. Survival of bacterial cells under laser irradiation with wavelength 532 nm in colloidal solution of PrF 3 nanoparticles was 39%, 34%, 20% for exposure times 5 minutes, 15 minutes and 30 minutes, correspondingly

  20. On-chip immunomagnetic separation of bacteria by in-flow dynamic manipulation of paramagnetic beads

    Science.gov (United States)

    Ahmed, Shakil; Noh, Jong Wook; Hoyland, James; de Oliveira Hansen, Roana; Erdmann, Helmut; Rubahn, Horst-Günter

    2016-11-01

    Every year, millions of people all over the world fall ill due to the consumption of unsafe food, where consumption of contaminated and spoiled animal origin product is the main cause for diseases due to bacterial growth. This leads to an intense need for efficient methods for detection of food-related bacteria. In this work, we present a method for integration of immunomagnetic separation of bacteria into microfluidic technology by applying an alternating magnetic field, which manipulates the paramagnetic beads into a sinusoidal path across the whole microchannel, increasing the probability for bacteria capture. The optimum channel geometry, flow rate and alternating magnetic field frequency were investigated, resulting in a capture efficiency of 68 %.

  1. Detection of BCG bacteria using a magnetoresistive biosensor: A step towards a fully electronic platform for tuberculosis point-of-care detection.

    Science.gov (United States)

    Barroso, Teresa G; Martins, Rui C; Fernandes, Elisabete; Cardoso, Susana; Rivas, José; Freitas, Paulo P

    2018-02-15

    Tuberculosis is one of the major public health concerns. This highly contagious disease affects more than 10.4 million people, being a leading cause of morbidity by infection. Tuberculosis is diagnosed at the point-of-care by the Ziehl-Neelsen sputum smear microscopy test. Ziehl-Neelsen is laborious, prone to human error and infection risk, with a limit of detection of 10 4 cells/mL. In resource-poor nations, a more practical test, with lower detection limit, is paramount. This work uses a magnetoresistive biosensor to detect BCG bacteria for tuberculosis diagnosis. Herein we report: i) nanoparticle assembly method and specificity for tuberculosis detection; ii) demonstration of proportionality between BCG cell concentration and magnetoresistive voltage signal; iii) application of multiplicative signal correction for systematic effects removal; iv) investigation of calibration effectiveness using chemometrics methods; and v) comparison with state-of-the-art point-of-care tuberculosis biosensors. Results present a clear correspondence between voltage signal and cell concentration. Multiplicative signal correction removes baseline shifts within and between biochip sensors, allowing accurate and precise voltage signal between different biochips. The corrected signal was used for multivariate regression models, which significantly decreased the calibration standard error from 0.50 to 0.03log 10 (cells/mL). Results show that Ziehl-Neelsen detection limits and below are achievable with the magnetoresistive biochip, when pre-processing and chemometrics are used. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Copper-adapted Suillus luteus, a symbiotic solution for pines colonizing Cu mine spoils.

    Science.gov (United States)

    Adriaensen, K; Vrålstad, T; Noben, J-P; Vangronsveld, J; Colpaert, J V

    2005-11-01

    Natural populations thriving in heavy-metal-contaminated ecosystems are often subjected to selective pressures for increased resistance to toxic metals. In the present study we describe a population of the ectomycorrhizal fungus Suillus luteus that colonized a toxic Cu mine spoil in Norway. We hypothesized that this population had developed adaptive Cu tolerance and was able to protect pine trees against Cu toxicity. We also tested for the existence of cotolerance to Cu and Zn in S. luteus. Isolates from Cu-polluted, Zn-polluted, and nonpolluted sites were grown in vitro on Cu- or Zn-supplemented medium. The Cu mine isolates exhibited high Cu tolerance, whereas the Zn-tolerant isolates were shown to be Cu sensitive, and vice versa. This indicates the evolution of metal-specific tolerance mechanisms is strongly triggered by the pollution in the local environment. Cotolerance does not occur in the S. luteus isolates studied. In a dose-response experiment, the Cu sensitivity of nonmycorrhizal Pinus sylvestris seedlings was compared to the sensitivity of mycorrhizal seedlings colonized either by a Cu-sensitive or Cu-tolerant S. luteus isolate. In nonmycorrhizal plants and plants colonized by the Cu-sensitive isolate, root growth and nutrient uptake were strongly inhibited under Cu stress conditions. In contrast, plants colonized by the Cu-tolerant isolate were hardly affected. The Cu-adapted S. luteus isolate provided excellent insurance against Cu toxicity in pine seedlings exposed to elevated Cu levels. Such a metal-adapted Suillus-Pinus combination might be suitable for large-scale land reclamation at phytotoxic metalliferous and industrial sites.

  3. Dynamic MR imaging of the temporomandibular joint arthrosis using spoiled GRASS sequence

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Shigeaki; Hamamoto, Sadatoshi; Kawano, Kazunori (Kagoshima Univ. (Japan). Dental School) (and others)

    1994-07-01

    The purpose of this study was to quantitatively evaluate contrast enhancement effects of the posterior disk attachment in the temporomandibular joint arthrosis using dynamic MRI with bilateral surface coils. One hundred twenty-four temporomandibular joints in 96 symptomatic patients and 27 control subjects were examined with a spoiled GRASS pulse sequence (TR: 35 ms, TE: 8 ms, flip angle: 60deg). One sagittal scan was performed prior to injection, then 0.1 mmol/kg of Gd-DTPA was given as a rapid bolus injection, immediately after which scans were performed at 30 seconds intervals for a period of 5 minutes. Signal intensity (SI) was measured from the ROI of the posterior disk attachment region. The contrast enhancement effects may be calculated by SI ratio (SIR) = ( SI[sup post]-SI[sup pre])/SI[sup pre], where SI[sup post] and SI[sup pre] were the signal intensities after and before administration of contrast medium. The time intensity curve of SIR versus time after injection was obtained on each symptoms. Join pain group (85 joints) tended to show a rapid enhancement pattern, while control group (54 joints), joint sound or opening limitation group (39 joints), and asymptomatic group (68 joints) showed a relatively gradual enhancement pattern. The drop of SIR in four groups were hardly observed during examination. Mean peak SIR of control group, joint pain group, joint sound or opening limitation group, and asymptomatic group was 0.62[+-]0.24 (SD), 1.53[+-]0.69, 0.73[+-]0.38 and 0.78[+-]0.44 respectively. The mean SIR of pain group was significantly (P<0.001, t-test) higher than that of other groups. These results suggested that dynamic MRI of the temporomandibular joint may effectively depict the inflammatory changes of the posterior disk attachment. (author).

  4. Dynamic MR imaging of the temporomandibular joint arthrosis using spoiled GRASS sequence

    International Nuclear Information System (INIS)

    Suenaga, Shigeaki; Hamamoto, Sadatoshi; Kawano, Kazunori

    1994-01-01

    The purpose of this study was to quantitatively evaluate contrast enhancement effects of the posterior disk attachment in the temporomandibular joint arthrosis using dynamic MRI with bilateral surface coils. One hundred twenty-four temporomandibular joints in 96 symptomatic patients and 27 control subjects were examined with a spoiled GRASS pulse sequence (TR: 35 ms, TE: 8 ms, flip angle: 60deg). One sagittal scan was performed prior to injection, then 0.1 mmol/kg of Gd-DTPA was given as a rapid bolus injection, immediately after which scans were performed at 30 seconds intervals for a period of 5 minutes. Signal intensity (SI) was measured from the ROI of the posterior disk attachment region. The contrast enhancement effects may be calculated by SI ratio (SIR) = ( SI post -SI pre )/SI pre , where SI post and SI pre were the signal intensities after and before administration of contrast medium. The time intensity curve of SIR versus time after injection was obtained on each symptoms. Join pain group (85 joints) tended to show a rapid enhancement pattern, while control group (54 joints), joint sound or opening limitation group (39 joints), and asymptomatic group (68 joints) showed a relatively gradual enhancement pattern. The drop of SIR in four groups were hardly observed during examination. Mean peak SIR of control group, joint pain group, joint sound or opening limitation group, and asymptomatic group was 0.62±0.24 (SD), 1.53±0.69, 0.73±0.38 and 0.78±0.44 respectively. The mean SIR of pain group was significantly (P<0.001, t-test) higher than that of other groups. These results suggested that dynamic MRI of the temporomandibular joint may effectively depict the inflammatory changes of the posterior disk attachment. (author)

  5. Remedial Investigation Report on Bear Creek Valley Operable Unit 2 (Rust Spoil Area, Spoil Area 1, and SY-200 Yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1, Main text

    International Nuclear Information System (INIS)

    1995-01-01

    This report on the BCV OU 2 at the Y-12 Plant, was prepared in accordance with requirements under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) for reporting the results of a site characterization for public review. It provides the Environmental Restoration Program with information about the results of the 1993 investigation. It includes information on risk assessments that have evaluated impacts to human health and the environment. Field activities included collection of subsurface soil samples, groundwater and surface water samples, and sediments and seep at the Rust Spoil Area (RSA), SY-200 Yard, and SA-1

  6. Remedial Investigation Report on Bear Creek Valley Operable Unit 2 (Rust Spoil Area, Spoil Area 1, and SY-200 Yard) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1, Main text

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    This report on the BCV OU 2 at the Y-12 Plant, was prepared in accordance with requirements under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) for reporting the results of a site characterization for public review. It provides the Environmental Restoration Program with information about the results of the 1993 investigation. It includes information on risk assessments that have evaluated impacts to human health and the environment. Field activities included collection of subsurface soil samples, groundwater and surface water samples, and sediments and seep at the Rust Spoil Area (RSA), SY-200 Yard, and SA-1.

  7. Coal Mining Spoil Heap Management as urban solid waste dump; Utilizacion de Escombreras de Carbon como Vertedero Controlado de Residuos Solidos Urbanos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    In the coordinated project DISPOSAL OF SOLID RESIDUES FROM COAL it is included the project Coal Mining Spoil Heap Management as Urban Solid Waste Dump. The main target of this project consisted of determining the viability of using coal mining spoil heaps, as controlled dubbish dump of urban solid wastes. The working plan to achieve this objective was composed of the following stages: 1. Urban solid wastes characterization. 2. Methodology to be followed for the selection of coal mining spoil heaps as controlled dump of urban solid wastes. 2.1 Classification and preliminary assessment of the possibility of using spoil heaps as urban solid waste dumps (APT/NON APT). 2.2 Realization of geological, geotechnical, hydrogeological and environmental studies applied to the spoil heaps classified as APT. 2.3 Analysis of the compatibility of the mining activity with the urban solid wastes dumped on the spoil heap. 2.4 Analysis of the use of coal mining wastes in the rubbish dump operative life. 3. Extraction of conclusions. The works were focused in the Leon province. As result of the researches we obtained the following results and conclusions: In the areas studied, only two emplacements are optima to dump urban solid wastes; spoil heap n. 13. Roguera Mine (Cinera-Matallana) and the open pit mine n. 4, Las Chaviadas, in Villablino. The active spoil heap use as controlled rubbish dump can cause, if not managed adequately, several coperating and occupational problems to the mine and to the company that manages the urban solid wastes. The abandoned spoil heap utilisation is difficult due to the problems that would arise when conditioning the site to be use as rubbish dump. The use of abandoned open pit mines, as controlled rubbish dump is feasible if geological, geotechnical, hydrogeological and environmental studies support it. It's possible the use of the coal mining wastes in the different operatives phases of the controlled rubbish dump. The evaluation methodology

  8. Coal Mining Spoil Heap Management as urban solid waste dump; Utilizacion de Escombreras de Carbon como Vertedero Controlado de Residuos Solidos Urbanos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    In the coordinated project DISPOSAL OF SOLID RESIDUES FROM COAL it is included the project Coal Mining Spoil Heap Management as Urban Solid Waste Dump. The main target of this project consisted of determining the viability of using coal mining spoil heaps, as controlled dubbish dump of urban solid wastes. The working plan to achieve this objective was composed of the following stages: 1. Urban solid wastes characterization. 2. Methodology to be followed for the selection of coal mining spoil heaps as controlled dump of urban solid wastes. 2.1 Classification and preliminary assessment of the possibility of using spoil heaps as urban solid waste dumps (APT/NON APT). 2.2 Realization of geological, geotechnical, hydrogeological and environmental studies applied to the spoil heaps classified as APT. 2.3 Analysis of the compatibility of the mining activity with the urban solid wastes dumped on the spoil heap. 2.4 Analysis of the use of coal mining wastes in the rubbish dump operative life. 3. Extraction of conclusions. The works were focused in the Leon province. As result of the researches we obtained the following results and conclusions: In the areas studied, only two emplacements are optima to dump urban solid wastes; spoil heap n. 13. Roguera Mine (Cinera-Matallana) and the open pit mine n. 4, Las Chaviadas, in Villablino. The active spoil heap use as controlled rubbish dump can cause, if not managed adequately, several coperating and occupational problems to the mine and to the company that manages the urban solid wastes. The abandoned spoil heap utilisation is difficult due to the problems that would arise when conditioning the site to be use as rubbish dump. The use of abandoned open pit mines, as controlled rubbish dump is feasible if geological, geotechnical, hydrogeological and environmental studies support it. It's possible the use of the coal mining wastes in the different operatives phases of the controlled rubbish dump. The evaluation methodology developed

  9. Chemical and isotopic tracing of underground water in relation with leaching of mine spoils, Nord-Pas-de-Calais Coal Basin (France)

    International Nuclear Information System (INIS)

    Denimal, S.; Tribovillard, N.; Meilliez, F.; Barbecot, F.; Dever, L.

    2001-01-01

    Coal mining activity in the Nord-Pas-de-Calais region (Northern France) has generated many mine spoils. The oxidation of the pyrite content of such coal shales and their leaching can be a source of sulfate pollution for the underlying chalk aquifer, i.e. the main drinking water resource of the region. Two sites of study have been retained: one in the free water table zone and the other in the confined water table zone. Samples from both mine spoils have been analyzed with respect to their carbon and sulfur content and a superficial leaching of these elements has been evidenced. Water has been sampled in piezometers and boreholes close to the mine spoils and also along natural flux lines. The use of sulfur isotopes as markers of the different sulfate sources has confirmed the spoils source but has permitted to identify another source in the second site which is the Tertiary gypsum-bearing Ostricourt sands. This study has shown also that in the confined water table zone, part of the exported sulfates is reduced. This bacterial reduction of sulfates is due to a joint leaching of both carbon and sulfur in the mine spoils. A self-purification phenomenon occurs when the chalk aquifer is confined beneath the Cenozoic cover. (J.S.)

  10. Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoil

    International Nuclear Information System (INIS)

    Joner, E.J.; Munier-Lamy, C.; Gouget, B.

    2007-01-01

    An old mine spoil at a 19. century mining site with considerable residues of uranium (400-800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humidified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An eco-toxicity bioassay using incorporation of [ 3 H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO 2 -citrate was similar to 120 μM as compared to 30 μM in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 mM UO 2 -citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bio-available U to affect indigenous microorganisms and that bio-available U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low. (authors)

  11. Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoil

    Energy Technology Data Exchange (ETDEWEB)

    Joner, E.J. [BIOFORSK, Soil and Environm Div, N-1432 As, (Norway); Munier-Lamy, C. [Univ Nancy 1, Fac Sci, Natl Ctr Rech Sci, Unit Mixte Rech 7137 LIMOS, F-54506 Vandoeuvre Les Nancy, (France); Gouget, B. [CEA Saclay, Lab Pierre Sue, F-91191 Gif Sur Yvette, (France)

    2007-07-01

    An old mine spoil at a 19. century mining site with considerable residues of uranium (400-800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humidified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An eco-toxicity bioassay using incorporation of [{sup 3}H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO{sub 2}-citrate was similar to 120 {mu}M as compared to 30 {mu}M in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 mM UO{sub 2}-citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bio-available U to affect indigenous microorganisms and that bio-available U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low. (authors)

  12. Bioavailability and microbial adaptation to elevated levels of uranium in an acid, organic topsoil forming on an old mine spoil.

    Science.gov (United States)

    Joner, Erik Jautris; Munier-Lamy, Colette; Gouget, Barbara

    2007-08-01

    An old mine spoil at a 19th-century mining site with considerable residues of uranium (400-800 mg U/kg) was investigated with respect to U concentrations in soil and plants and tolerance to U in the soil microbial community in order to describe the bioavailability of U. Measurements of soil fractions representing water-soluble U, easily exchangeable U, and U bound to humified organic matter showed that all fractions contained elevated concentrations of U. Plant U concentrations were only 10 times higher at the mine spoil site compared to the reference site (3 mg U/kg vs 0.3 mg U/kg), while the most easily available soil fractions contained 0.18 to 0.86 mg U/kg soil at the mine spoil. An ecotoxicity bioassay using incorporation of [3H]thymidine into the indigenous microbial communities of the two soils in the presence of increasing U concentrations showed that microorganisms at the mining site were sensitive to U but also that they had acquired a substantial tolerance toward U (EC50, the effective concentration reducing activity by 50% of UO2-citrate was approximately 120 microM as compared to 30 microM in the reference soil). In the assay, more than 40% of the microbial activity was maintained in the presence of 1 mM UO2-citrate versus 3% in the reference soil. We conclude that U-enriched mining waste can contain sufficiently elevated concentrations of bioavailable U to affect indigenous microorganisms and that bioavailable U imposes a selection pressure that favors the development of a highly uranium-tolerant microbial community, while plant uptake of U remains low.

  13. Comparative growth behaviour and leaf nutrient status of native trees planted on mine spoil with and without nutrient amendment

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.; Singh, J.S. [Banaras Hindu University, Varanasi (India). Dept. of Botany

    2001-07-01

    The effect of nutrient amendment on growth of nine indigenous tree species planted on coal mine spoil was studied. Greater growth in fertilized plots was accompanied by greater foliar N and P concentrations in all species. The response to fertilization varied among species and was greater in non-leguminous than in leguminous species. Furthermore, leguminous species exhibited higher growth rates compared to non-leguminous species. Acacia catechu, Dalbergia sissoo, Gmelina arborea and Azadirachta indica fitted the elastic similarity model of tree growth; whereas Pongamia pinnata and Phyllanthus emblica followed the constant stress model. Tectona grandis was the only species which fitted the geometric similarity model.

  14. Effects of inorganic electron acceptors on methanogenesis and methanotrophy and on the community structure of bacteria and archaea in sediments of a boreal lake

    Science.gov (United States)

    Rissanen, Antti J.; Karvinen, Anu; Nykänen, Hannu; Peura, Sari; Tiirola, Marja; Mäki, Anita; Kankaala, Paula

    2016-04-01

    Lake sediments are globally significant sources of CH4 to the atmosphere, but the factors controlling the production and consumption of CH4 in these systems are understudied. Increasing availability of electron acceptors (EA) (other than CO2) in sediments can decrease or even suppress CH4 production by diverting the electron flow (from H2 and organic substances) from methanogenic to other anaerobic respiration pathways. However, whether these changes in microbial function extend down to changes in the structure of microbial communities is not known. Also anaerobic oxidation of methane (AOM) could be enhanced by increased availability of EAs (SO42-, NO3-, Fe3+ and Mn4+), but information on the role of this process in lake sediments is scarce. We studied the effects of inorganic EAs on the potential for CH4 production and consumption and on the structure of microbial communities in sediments of a boreal lake. Anoxic slurries of sediment samples collected from two depths (0 - 10 cm; 10 - 30 cm) of the profundal zone of a boreal, mesotrophic Lake Ätäskö, were amended with 1) CH4 or with CH4 and either 2) 10 mM Mn4+, 3) 10 mM Fe3+, 4) O2 or 5) CH2F2 (inhibitor of aerobic methane oxidation) and incubated at +10° C for up to 4 months. Furthermore, slurries from the 10 - 30 cm layer were amended with CH4 and either 6) 2 mM NO3- or 7) 2 mM SO42- and incubated at +4 ° C for up to 14 months. The processes were measured using 13C-labelling and by concentration measurements of CH4 and CO2. Effects of treatments 1-3 on microbial communities were also analysed by next-generation sequencing of 16S rRNA, as well as methyl coenzyme-M reductase gene amplicons and mRNA transcripts. CH4 production (max. 83 nmol gdw-1d-1) took place in the anaerobic treatments but was generally decreased by the addition of NO3-, SO42-, Fe3+ and Mn4+. Although the structure of sediment archaeal community was resistant to Fe3+/Mn4+ - additions, slight changes in the structure of bacterial community

  15. Toxicity evaluation of e-juice and its soluble aerosols generated by electronic cigarettes using recombinant bioluminescent bacteria responsive to specific cellular damages.

    Science.gov (United States)

    Bharadwaj, Shiv; Mitchell, Robert J; Qureshi, Anjum; Niazi, Javed H

    2017-04-15

    Electronic-cigarettes (e-cigarette) are widely used as an alternative to traditional cigarettes but their safety is not well established. Herein, we demonstrate and validate an analytical method to discriminate the deleterious effects of e-cigarette refills (e-juice) and soluble e-juice aerosol (SEA) by employing stress-specific bioluminescent recombinant bacterial cells (RBCs) as whole-cell biosensors. These RBCs carry luxCDABE-operon tightly controlled by promoters that specifically induced to DNA damage (recA), superoxide radicals (sodA), heavy metals (copA) and membrane damage (oprF). The responses of the RBCs following exposure to various concentrations of e-juice/SEA was recorded in real-time that showed dose-dependent stress specific-responses against both the e-juice and vaporized e-juice aerosols produced by the e-cigarette. We also established that high doses of e-juice (4-folds diluted) lead to cell death by repressing the cellular machinery responsible for repairing DNA-damage, superoxide toxicity, ion homeostasis and membrane damage. SEA also caused the cellular damages but the cells showed enhanced bioluminescence expression without significant growth inhibition, indicating that the cells activated their global defense system to repair these damages. DNA fragmentation assay also revealed the disintegration of total cellular DNA at sub-toxic doses of e-juice. Despite their state of matter, the e-juice and its aerosols induce cytotoxicity and alter normal cellular functions, respectively that raises concerns on use of e-cigarettes as alternative to traditional cigarette. The ability of RBCs in detecting both harmful effects and toxicity mechanisms provided a fundamental understanding of biological response to e-juice and aerosols. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Growth and nutritional status of Brazilian wood species Cedrella fissilis and Anadenanthera peregrina in bauxite spoil in response to arbuscular mycorrhizal inoculation and substrate amendment

    Directory of Open Access Journals (Sweden)

    Tótola Marcos Rogério

    2000-01-01

    Full Text Available The growth of Cedrella fissilis Vell. (Cedro Rosa and of Anadenanthera peregrina Benth (Angico Vermelho in bauxite spoil was studied to evaluate their response to substrate amendment or to inoculation with arbuscular mycorrhizal fungi (AMF. The plants were grown in bauxite spoil, topsoil or spoil amended with either topsoil or compost, and inoculated with the AMF Acaulospora scrobiculata, Gigaspora margarita or Glomus etunicatum. Root colonization was highly dependent on the interaction plant-fungus-substrate. In C. fissilis, root colonization by Gigaspora margarita dropped from 75% in bauxite spoil to only 4% in topsoil. Contrarily, root colonization of A. peregrina by the same fungus increased from 48% in spoil to 60% in topsoil. Root colonization of C. fissilis in topsoil was lower than in the three other substrates. The opposite was observed for A. peregrina. Inoculation of the plants with Acaulospora scrobiculata or Glomus etunicatum was very effective in promoting plant growth. Plants of both C. fissilis and A. peregrina did not respond to amendments of bauxite spoil unless they were mycorrhizal. Also, a preferential partitioning of photosynthates to the shoots of A. peregrina inoculated with G. etunicatum or A. scrobiculata, and of C. fissilis inoculated with any of the three species of AMF was observed. C. fissilis showed a greater response to mycorrhizal inoculation than A. peregrina. The mean mycorrhizal efficiency (ME for dry matter production by C. fissilis was 1,847% for A. scrobiculata, 1,922% for G. etunicatum, and 119% for G. margarita. In A. peregrina, the ME was 249% for A. scrobiculata, 540% for G. etunicatum, and 50% for G. margarita. The effect of mycorrhizal inoculation on plant growth seems to be related in part to an enhanced phosphorus absorption by inoculated plants. Moreover, the efficiency with which the absorbed nutrients were used to produce plant biomass was much greater in plants inoculated with A. scrobiculata or

  17. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  18. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  19. Quantitative determination of sediment movement at the landward spoil ground in the Yangtze Estuary with radioactive tracer

    International Nuclear Information System (INIS)

    Li Zhangsu

    1993-01-01

    A radioactive tracer experiment was carried out at the landward spoil ground of the North Passage in the Yangtze Estuary in June of 1991. The scandium-46 was selected as the tracer, the total activity released is 17.95 x 10 10 Bq(4.85 Ci), the amount of the scandium-46 glass is 495 g. The purpose of the experiment is to determine the sediment movement direction, path, velocity and transport rate. The experiment provides the direct evidence for using the landward spoil ground in the future. The experiment results show the sediment movement was governed by the ebb tide current during the period of middle and neap tides when the radioactive tracer was injected both on the flood and ebb tides, and the sediment moved from the injection points to the middle of the North Passage near the navigation buoy No. 269. The direction of the sediment movement is 110 degree, the particle velocity is 758 m/d, and the sediment transport rate per unit width is 47.8 m 3 /md

  20. Radiation-induced enhancement of antifungal activity of chitosan on fruit-spoiling fungi during postharvest storage

    Energy Technology Data Exchange (ETDEWEB)

    Diep, Tran Bang; Lam, Nguyen Duy; Quynh, Tran Minh [Institute for Nuclear Science and Technique-VAEC, Hanoi (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Experiment conducted four fruit-spoiling fungal strains that were isolated from spoilt fruits (mango and dragon fruit) and were identified as follows: Fusarium dimerum Penzig, Aspergillus nidulans Wint, Aspergillus fumigatus Fresenius and Aspergillus japonicus Saito. Chitosan samples with various deacetylation degree (70-99%) were irradiated at doses ranging from 20 to 200kGy, then were supplemented to liquid medium for growth of fungi. We have found that chitosan possesses not only well known antibacterial activity but also the antifungal one on fruit-spoiling fungi. Method of fungal cultivation using liquid medium showed that it has higher sensitivity compared with the cultivation on agar plate, so we recommend this method should be used for evaluation of antimicrobial activity of chitosan. Our study also indicated that deacetylation degree of chitosan clearly affects its antifungal activity, the higher the deacetylation of chitosan, stronger antifungal activity can be observed. This finding recommends the use of chitosan with higher deacetylation for fruit coating and other pharmacology utilization. Results from the minimal inhibitory concentrations (MIC) on fungal growth showed that radiation treatment increased antifungal activity of chitosan and dose of 60kGy gave highest activity. (author)

  1. Environmental risk evaluation of the use of mine spoils and treated sewage sludge in the ecological restoration of limestone quarries

    Science.gov (United States)

    Jordán, M. M.; Pina, S.; García-Orenes, F.; Almendro-Candel, M. B.; García-Sánchez, E.

    2008-07-01

    The ecologic restoration criteria in areas degraded from extraction activities require making use of their mine spoils. These materials do not meet fertility conditions to guarantee restoration success and therefore, need the incorporation of organic amendments to obtain efficient substratum. Reducing the deficiencies in the organic material and restoration material nutrients with the contribution of treated sewage sludge is proposed in this work. This experiment was based on a controlled study using columns. The work was conducted with two mine spoils, both very rich in calcium carbonate. The first mineral, of poor quality, came from the formation of aggregates of crushed limestone ( Z). The other residual material examined originated in limestone extraction, formed by the levels of interspersed non-limestone materials and the remains of stripped soils ( D). Two treatments were undertaken (30,000 and 90,000 kg/ha of sewage sludge), in addition to a control treatment. The water contribution was carried out with a device that simulated either short-duration rain or a flooding irrigation system in order to cover the surface and then percolate through the soil. The collection of leached water took place 24 h after the applications. Different parameters of the leached water were determined, including pH, electrical conductivity, nitrate anions, ammonium, phosphates, sulphates and chlorides. The values obtained for each irrigation application are discussed, and the nitrate values obtained were very elevated.

  2. Radiation-induced enhancement of antifungal activity of chitosan on fruit-spoiling fungi during postharvest storage

    International Nuclear Information System (INIS)

    Diep, Tran Bang; Lam, Nguyen Duy; Quynh, Tran Minh; Kume, Tamikazu

    2001-01-01

    Experiment conducted four fruit-spoiling fungal strains that were isolated from spoilt fruits (mango and dragon fruit) and were identified as follows: Fusarium dimerum Penzig, Aspergillus nidulans Wint, Aspergillus fumigatus Fresenius and Aspergillus japonicus Saito. Chitosan samples with various deacetylation degree (70-99%) were irradiated at doses ranging from 20 to 200kGy, then were supplemented to liquid medium for growth of fungi. We have found that chitosan possesses not only well known antibacterial activity but also the antifungal one on fruit-spoiling fungi. Method of fungal cultivation using liquid medium showed that it has higher sensitivity compared with the cultivation on agar plate, so we recommend this method should be used for evaluation of antimicrobial activity of chitosan. Our study also indicated that deacetylation degree of chitosan clearly affects its antifungal activity, the higher the deacetylation of chitosan, stronger antifungal activity can be observed. This finding recommends the use of chitosan with higher deacetylation for fruit coating and other pharmacology utilization. Results from the minimal inhibitory concentrations (MIC) on fungal growth showed that radiation treatment increased antifungal activity of chitosan and dose of 60kGy gave highest activity. (author)

  3. Effect of microbial cell-free meat extract on the growth of spoilage bacteria.

    Science.gov (United States)

    Nychas, G-J E; Dourou, D; Skandamis, P; Koutsoumanis, K; Baranyi, J; Sofos, J

    2009-12-01

    This study examined the effect of microbial cell-free meat extract (CFME) derived from spoiled meat, in which quorum sensing (QS) compounds were present, on the growth kinetics (lag phase, and growth rate) of two spoilage bacteria, Pseudomonas fluorescens and Serratia marcescens. Aliquots of CFME from spoiled meat were transferred to Brain Heart Infusion broth inoculated with 10(3) CFU ml(-1) of 18 h cultures of Ps. fluorescens or Ser. marcescens, both fresh meat isolates; CFME derived from unspoiled fresh meat ('clean' meat) served as a control. Changes in impedance measurements were monitored for 48 h, and the detection time (Tdet) was recorded. It was found that in the absence of CFME containing QS compounds the Tdet was shorter (P meat. The rate of growth of Ps. fluorescens, recorded as the maximum slope rate of conductance changes (MSrCC), after Tdet, was higher (P meat. Similar results in MSrCC of impedance changes were obtained for Ser. marcescens. The study indicated that the growth rate (expressed in MSrCC units) of meat spoilage bacteria in vitro was enhanced in samples supplemented with CFME containing QS compounds compared to control samples (i.e., without CFME or with CFME from 'clean' meat). This behaviour may explain the dominant role of these two bacteria in the spoilage of meat. These results illustrate the potential effect of signalling compounds released during storage of meat on the behaviour of meat spoilage bacteria. Understanding such interactions may assist in the control of fresh meat quality and the extension of its shelf life.

  4. Electron dynamics inside short-coherence systems

    International Nuclear Information System (INIS)

    Ferrari, Giulio; Bordone, Paolo; Jacoboni, Carlo

    2006-01-01

    We present theoretical results on electron dynamics inside nanometric systems, where the coherence of the electron ensemble is maintained in a very short region. The contacts are supposed to spoil such a coherence, therefore the interference processes between the carrier wavefunction and the internal potential profile can be affected by the proximity of the contacts. The problem has been analysed by using the Wigner-function formalism. For very short devices, transport properties, such as tunnelling through potential barriers, are significantly influenced by the distance between the contacts

  5. Biotechnological applications of acetic acid bacteria.

    Science.gov (United States)

    Raspor, Peter; Goranovic, Dusan

    2008-01-01

    The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other

  6. Redemption of the "spoiled identity:" the role of HIV-positive individuals in HIV care cascade interventions.

    Science.gov (United States)

    Camlin, Carol S; Charlebois, Edwin D; Geng, Elvin; Semitala, Fred; Wallenta, Jeanna; Getahun, Monica; Kampiire, Leatitia; Bukusi, Elizabeth A; Sang, Norton; Kwarisiima, Dalsone; Clark, Tamara D; Petersen, Maya L; Kamya, Moses R; Havlir, Diane V

    2017-12-01

    The concept of "therapeutic citizenship" has drawn attention to ways in which public testimony, the "story-telling in the public sphere" undertaken by people living with HIV (PLHIV), has shaped the global response to the epidemic. This paper presents qualitative findings from two large studies in eastern Africa that reveal how the advent of population-based HIV testing campaigns and efforts to accelerate antiretroviral "treatment for all" has precipitated a rapidly expanding therapeutic citizenship "project," or social movement. The title of this paper refers to Goffman's original conceptualization of stigma as a social process through which a person's identity is rendered "spoiled." Data were derived from qualitative studies embedded within two clinical trials, Sustainable East African Research in Community Health (SEARCH) (NCT# 01864603) in Kenya and Uganda, and START-ART (NCT# 01810289) in Uganda, which aimed to offer insights into the pathways through which outcomes across the HIV care continuum can be achieved by interventions deployed in the studies, any unanticipated consequences, and factors that influenced implementation. Qualitative in-depth semi-structured interviews were conducted among cohorts of adults in 2014 through 2015; across both studies and time periods, 217 interviews were conducted with 166 individuals. Theoretically informed, team-based analytic approaches were used for the analyses. Narratives from PLHIV, who have not always been conceptualized as actors but rather usually as targets of HIV interventions, revealed strongly emergent themes related to these individuals' use of HIV biomedical resources and discourses to fashion a new, empowered subjecthood. Experiencing the benefits of antiretroviral therapy (ART) emboldens many individuals to transform their "spoiled" identities to attain new, valorized identities as "advocates for ART" in their communities. We propose that the personal revelation of what some refer to as the "gospel of ARVs

  7. Ameliorating effects of industrial sugar residue on the Jales gold mine spoil (NE Portugal) using Holcus lanatus and Phaseolus vulgaris as indicators

    Energy Technology Data Exchange (ETDEWEB)

    Bleeker, P.M.; Teiga, P.M.; Santos, M.H.; Koe, T. de; Verkleij, J.A.C

    2003-09-01

    A residue of the sugar industry can be used in revegetation programs on metal contaminated sites. - Phytostabilisation of bare heavily contaminated substrate, such as abandoned mine sites, is considered a very appropriate technology in order to diminish erosion and dispersion of contaminants into the surroundings. In this short-term pot study, application of industrial sugar residue (ISR), a waste product of the sugar industry, proved to ameliorate spoils conditions for plant performance by elevating pH and immobilising several metals. Although arsenate concentrations were positively correlated to spoil pH and spoil treatment with ISR mobilised As, growth of both Phaseolus vulgaris and Holcus lanatus improved significantly after applications of 3.75 g ISR kg{sup -1} dry spoil. Nutrient uptake from the substrate, with the exception of potassium, was elevated by ISR. As a remediation technique ISR application could be effective although in As-contaminated sites application might be restricted to areas where leaching to (ground) water does not form a risk.

  8. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Renella, Giancarlo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)], E-mail: giancarlo.renella@unifi.it; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)

    2008-04-15

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness.

  9. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    International Nuclear Information System (INIS)

    Renella, Giancarlo; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo

    2008-01-01

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness

  10. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  11. [3D FSPGR (fast spoiled gradient echo) magnetic resonance imaging in the diagnosis of focal cortical dysplasia in children].

    Science.gov (United States)

    Alikhanov, A A; Sinitsyn, V E; Perepelova, E M; Mukhin, K Iu; Demushkina, A A; Omarova, M O; Piliia, S V

    2001-01-01

    Small dysplastic lesions of the cerebral cortex are often missed by conventional MRI methods. The identification of subtle structural abnormalities by traditional multiplanar rectilinear slices is often limited by the complex convolutional pattern of the brain. We used a method of FSPGR (fast spoiled gradient-echo) of three-dimensional MRI data that improves the anatomical display of the sulcal structure of the hemispheric convexities. It also reduces the asymmetric sampling of gray-white matter that may lead to false-positive results. We present 5 from 12 patients with dysplastic cortical lesions in whom conventional two-dimensional and three-dimensional MRI with multiplanar reformatting was initially considered normal. Subsequent studies using 3D FSPGR identified various types of focal cortical dysplasia in all. These results indicate that an increase in the detection of subtle focal dysplastic lesions may be accomplished when one improves the anatomical display of the brain sulcal structure by performing 3D FSPGR.

  12. Rehabilitation of semi-arid coal mine spoil bank soils with mine residues and farm organic by-products

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.; Bosch-Serra, A.; Estudillos, G.; Poch, R.M. [University of Lleida, Lleida (Spain). Dept. of Environmental & Soil Science

    2009-07-01

    A method of rehabilitating coal mine soils was studied under the conditions of a semi-arid climate, lack of topsoil but availability of farm by-products in NE Spain. The objectives of the research were to assess a new method in order to achieve a suitable substrate for the establishment of native vegetation, to evaluate environmental impacts associated with the reclamation process, and to determine the time necessary to integrate the treated area into the surrounding environment. Eight plots (10 x 35 m{sup 2}) were established in September 1997. Substrate combinations of two types of mine spoil (coal dust and coarse-sized material), two levels of pig slurry (39 and 94 Mg ha{sup -1}dry-wt), and cereal straw (0 and 15 Mg ha{sup -1}) were applied. Monitoring of select physical and chemical soil properties and vegetation characteristics was performed from 1997 until 2005. The bulk density and the saturated hydraulic conductivity measured did not limit plant development and water availability. Initial substrate salinity (1.37 S m{sup -1}) decreased with time and in the long term did not limit plant colonization to salinity-adapted species. Initial nitrate concentration was 298 mg kg{sup -1}, but was reduced significantly to acceptable values in 3 years (55 mg kg{sup -1}) and the measured pH (7.6) was maintained at the level of initial spoil values. Vegetation cover reached up to 90%. In the treated area, spontaneous vegetation cover (15 to 70%) colonized the nonsown areas widely. In the medium term, vegetation cover tended to be higher in plots with a thicker layer of coal dust material and the higher slurry rate. Soil rehabilitation and environmental reintegration, taking into account soil and vegetation indicators, was possible in the studied area with low cost inputs using residual materials from mining activities and animal husbandry by-products.

  13. How honey kills bacteria

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Speijer, Dave; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

  14. Femtosecond and Subfemtosecond X-Ray Pulses from a SASE Based Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Emma, P

    2004-03-10

    We propose a novel method to generate femtosecond and sub-femtosecond photon pulses in a free electron laser by selectively spoiling the transverse emittance of the electron beam. Its merits are simplicity and ease of implementation. When the system is applied to the Linac Coherent Light Source, it can provide x-ray pulses the order of 1 femtosecond in duration containing about 1010 transversely coherent photons.

  15. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  16. A study of magnetic properties of magnetotatic bacteria

    International Nuclear Information System (INIS)

    Wajnberg, E.; Souza, L.H. de; Barros, H.G. de P.L. de; Esquivel, D.M.S.

    1985-01-01

    The average magnetic moment and its anisotropy are determined in natural samples of magnetotactic bacteria at 4.2 K using a SQUID magnetometer. The results are in good agreement with estimates made from electron micrographs. (Author) [pt

  17. Presence of acylated homoserine lactones (AHLs) and AHL-producing bacteria in meat and potential role of AHL in spoilage of meat

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Christensen, Allan Beck; Flodgaard, Lars

    2004-01-01

    Quorum-sensing (QS) signals (N-acyl homoserine lactones [AHLs]) were extracted and detected from five commercially produced vacuum-packed meat samples. Ninety-six AHL-producing bacteria were isolated, and 92 were identified as Enterobacteriaceae. Hafnia alvei was the most commonly identified AHL......-producing bacterium. Thin-layer chromatographic profiles of supernatants from six H. alvei isolates and of extracts from spoiling meat revealed that the major AHL species had an R-f value and shape similar to N-3-oxo-hexanoyl homoserine lactone (OHHL). Liquid chromatography-mass spectrometry (MS) (high-resolution MS...

  18. Application of Lactic Acid Bacteria (LAB) in freshness keeping of tilapia fillets as sashimi

    Science.gov (United States)

    Cao, Rong; Liu, Qi; Chen, Shengjun; Yang, Xianqing; Li, Laihao

    2015-08-01

    Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria (LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19 (obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.

  19. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  20. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Bacteria are thought to be examples of organisms that do not age. They divide by .... carry genetic material to the next generation through the process of reproduction; they are also .... molecules, and modified proteins. This report revealed that ...

  1. Social Behaviour in Bacteria

    Indian Academy of Sciences (India)

    Administrator

    the recipient. • Social behaviours can be categorized according to the fitness ... is actually the flagella of symbiotic spirochete bacteria that helps it to swim around .... Normal population. Responsive switching. (Environmental stress). Stochastic.

  2. [Darwin and bacteria].

    Science.gov (United States)

    Ledermann D, Walter

    2009-02-01

    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  3. Lipopolysaccharides in diazotrophic bacteria

    OpenAIRE

    Serrato, Rodrigo V.

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are...

  4. Fat-suppressed three-dimensional fast spoiled gradient-recalled echo imaging: a modified FS 3D SPGR technique for assessment of patellofemoral joint chondromalacia.

    Science.gov (United States)

    Wang, S F; Cheng, H C; Chang, C Y

    1999-01-01

    Fast fat-suppressed (FS) three-dimensional (3D) spoiled gradient-recalled echo (SPGR) imaging of 64 articular cartilage regions in 16 patellofemoral joints was evaluated to assess its feasibility in diagnosing patellofemoral chondromalacia. It demonstrated good correlation with arthroscopic reports and took about half of the examination time that FS 3D SPGR did. This modified, faster technique has the potential to diagnose patellofemoral chondromalacia with shorter examination time than FS 3D SPGR did.

  5. Lipopolysaccharides in diazotrophic bacteria.

    Science.gov (United States)

    Serrato, Rodrigo V

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  6. AIDS: "it's the bacteria, stupid!".

    Science.gov (United States)

    Broxmeyer, Lawrence; Cantwell, Alan

    2008-11-01

    Acid-fast tuberculous mycobacterial infections are common in AIDS and are regarded as secondary "opportunistic infections." According to the National Institute of Allergy and Infectious Diseases, TB is the major attributable cause of death in AIDS patients. Could such bacteria play a primary or causative role in AIDS? Certainly, In screening tests for HIV, there is frequent, up to 70%, cross-reactivity, between the gag and pol proteins of HIV and patients with mycobacterial infections such as tuberculosis. By 1972, five years before gays started dying in the U.S., Rolland wrote Genital Tuberculosis, a Forgotten Disease? And ironically, in 1979, on the eve of AIDS recognition, Gondzik and Jasiewicz showed that even in the laboratory, genitally infected tubercular male guinea pigs could infect healthy females through their semen by an HIV-compatible ratio of 1 in 6 or 17%, prompting him to warn his patients that not only was tuberculosis a sexually transmitted disease, but also the necessity of the application of suitable contraceptives, such as condoms, to avoid it. Gondzik's solution and date of publication are chilling; his findings significant. Since 1982 Cantwell et al found acid-fast bacteria closely related to tuberculosis (TB) and atypical tuberculosis in AIDS tissue. On the other hand molecular biologist and virologist Duesberg, who originally defined retroviral ultrastructure, has made it clear that HIV is not the cause of AIDS and that the so-called AIDS retrovirus has never been isolated in its pure state. Dr. Etienne de Harven, first to examine retroviruses under the electron, agrees. In 1993 HIV co-discoverer Luc Montagnier reported on cell-wall-deficient (CWD) bacteria which he called "mycoplasma" in AIDS tissue. He suspected these as a necessary "co-factor" for AIDS. Remarkably, Montagnier remained silent on Cantwell's reports of acid-fast bacteria which could simulate "mycoplasma" in AIDS tissue. Mattman makes clear that the differentiation between

  7. Nomograms to calculate stability in slate and granite spoil heaps; Abacos para el calculo de estabilidad en escombreras de pizarra y granito

    Energy Technology Data Exchange (ETDEWEB)

    Paz Freire, M.; Taboada Castro, J.; Rivas Brea, T.; Giraldez Perez, E.; Araujo Fernandez, M.

    2011-07-01

    One of the main problems involved in the mining of slate and ornamental granite is the unavoidable generation of waste rock, which must be stored in spoil heaps under suitably integrated, secure and stable conditions. Our work here focuses on this last point. To study the risk of instability within spoil heaps we have analysed the performance of a wide number of models with regard to circular slope failure, taking into account the different degrees of compactness of the material, the characteristics of the material itself, the effect of water pressure and the geometry of the heap. From this analysis we obtained more than 300 safety criteria, which were then used to draw up a series of nomograms to allow us to determine the risk of sliding in any granite or slate spoil heap. Thus, nomograms prove themselves to be suitable, quick, easy-to-use tools for preliminary studies of new structures, for periodic analyses of existing structures and to investigate structures that are due to be modified. (Author) 24 refs.

  8. Integration of thermal digital 3D model and a MASW (Multichannel Analysis of Surface Wave) as a means of improving monitoring of spoil tip stability

    Science.gov (United States)

    Lewińska, Paulina; Matuła, Rafał; Dyczko, Artur

    2018-01-01

    Spoil tips are anthropogenic terrain structures built of leftover (coal) mining materials. They consist mostly of slate and sandstone or mudstone but also include coal and highly explosive coal dust. Coal soil tip fires cause an irreversible degradation to the environment. Government organizations notice the potential problem of spoil tip hazard and are looking for ways of fast monitoring of their temperature and inside structure. In order to test new monitoring methods an experimental was performed in the area of spoil tip of Lubelski Węgiel "Bogdanka" S.A. A survey consisted of creating a 3D discreet thermal model. This was done in order to look for potential fire areas. MASW (Multichannel analysis of surface wave) was done in order to find potential voids within the body of a tip. Existing data was digitalized and a 3D model of object's outside and inside was produced. This article provides results of this survey and informs about advantages of such an approach.

  9. Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India

    Energy Technology Data Exchange (ETDEWEB)

    Singh, A.N.; Zeng, D.H.; Chen, F.S. [Chinese Academy of Science, Shenyang (China). Inst. of Applied Ecology

    2005-07-01

    Total concentration of heavy metals (Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

  10. Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India.

    Science.gov (United States)

    Singh, Anand N; Zeng, De-hui; Chen, Fu-sheng

    2005-01-01

    Total concentration of heavy metals (Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

  11. Integration of thermal digital 3D model and a MASW (Multichannel Analysis of Surface Wave as a means of improving monitoring of spoil tip stability

    Directory of Open Access Journals (Sweden)

    Lewińska Paulina

    2018-01-01

    Full Text Available Spoil tips are anthropogenic terrain structures built of leftover (coal mining materials. They consist mostly of slate and sandstone or mudstone but also include coal and highly explosive coal dust. Coal soil tip fires cause an irreversible degradation to the environment. Government organizations notice the potential problem of spoil tip hazard and are looking for ways of fast monitoring of their temperature and inside structure. In order to test new monitoring methods an experimental was performed in the area of spoil tip of Lubelski Węgiel „Bogdanka” S.A. A survey consisted of creating a 3D discreet thermal model. This was done in order to look for potential fire areas. MASW (Multichannel analysis of surface wave was done in order to find potential voids within the body of a tip. Existing data was digitalized and a 3D model of object’s outside and inside was produced. This article provides results of this survey and informs about advantages of such an approach.

  12. Relationship between the trochlear groove angle and patellar cartilage morphology defined by 3D spoiled gradient-echo imaging

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Yuko; Tokuda, Osamu; Matsunaga, Naofumi [Yamaguchi University Graduate School of Medicine, Department of Radiology, Yamaguchi (Japan); Fukuda, Kouji [Shunan Memorial Hospital, Division of Radiological Technology, Yamaguchi (Japan); Shiraishi, Gen; Motomura, Tetsuhisa [Shunan Memorial Hospital, Department of Orthopedics Surgery, Yamaguchi (Japan); Kimura, Motoichi [Customer Application Gr., GE Healthcare MR Sales and Marketing Department, Osaka (Japan)

    2012-05-15

    To examine whether the femoral trochlear groove angle (TGA) is a determinant of the patellar cartilage volume and patellar cartilage damage. Patellar cartilage was evaluated by MR imaging in 66 patients (22 males and 44 females) with knee pain. Fat-suppressed 3D spoiled gradient-echo images were used to calculate the cartilage volume and to grade the cartilage damage. The proximal and distal TGAs were measured from axial PD-weighted FSE MR images with fat suppression. For every increase in the TGA at the distal femur, the patellar cartilage volume was significantly increased by 6.07 x 10{sup -3} cm{sup 3} (95% CI: 1.27 x 10{sup -3}, 10.9 x 10{sup -3}) after adjustment for age, gender, and patellar bone volume (P < 0.05). The MR grade of medial patellar cartilage damage progressed as the distal TGA became narrower, although there was no significant correlation between the distal TGA and the MR grading of patellar cartilage damage. A more flattened distal TGA was associated with increased patellar cartilage volume. However, there was no association between TGA and patellar cartilage defects. (orig.)

  13. Aluminum-Tolerant Pisolithus Ectomycorrhizas Confer Increased Growth, Mineral Nutrition, and Metal Tolerance to Eucalyptus in Acidic Mine Spoil

    Directory of Open Access Journals (Sweden)

    Louise Egerton-Warburton

    2015-01-01

    Full Text Available Ectomycorrhizal fungi (ECM may increase the tolerance of their host plants to Al toxicity by immobilizing Al in fungal tissues and/or improving plant mineral nutrition. Although these benefits have been demonstrated in in vitro (pure culture or short-term nutrient solution (hydroponic experiments, fewer studies have examined these benefits in the field. This study examined the growth, mineral nutrition, and Al levels in two Eucalyptus species inoculated with three Pisolithus ecotypes that varied in Al tolerance (in vitro and grown in mine spoil in the greenhouse and field. All three ecotypes of Pisolithus improved Eucalyptus growth and increased host plant tolerance to Al in comparison to noninoculated plants. However, large variations in plant growth and mineral nutrition were detected among the Pisolithus-inoculated plants; these differences were largely explained by the functional properties of the Pisolithus inoculum. Seedlings inoculated with the most Al-tolerant Pisolithus inoculum showed significantly higher levels of N, P, Ca, Mg, and K and lower levels of Al than seedlings inoculated with Al-sensitive ecotypes of Pisolithus. These findings indicate an agreement between the fungal tolerance to Al in vitro and performance in symbiosis, indicating that both ECM-mediated mineral nutrient acquisition and Al accumulation are important in increasing the host plant Al tolerance.

  14. Plant Communities Rather than Soil Properties Structure Arbuscular Mycorrhizal Fungal Communities along Primary Succession on a Mine Spoil

    Science.gov (United States)

    Krüger, Claudia; Kohout, Petr; Janoušková, Martina; Püschel, David; Frouz, Jan; Rydlová, Jana

    2017-01-01

    Arbuscular mycorrhizal fungal (AMF) community assembly during primary succession has so far received little attention. It remains therefore unclear, which of the factors, driving AMF community composition, are important during ecosystem development. We addressed this question on a large spoil heap, which provides a mosaic of sites in different successional stages under different managements. We selected 24 sites of c. 12, 20, 30, or 50 years in age, including sites with spontaneously developing vegetation and sites reclaimed by alder plantations. On each site, we sampled twice a year roots of the perennial rhizomatous grass Calamagrostis epigejos (Poaceae) to determine AMF root colonization and diversity (using 454-sequencing), determined the soil chemical properties and composition of plant communities. AMF taxa richness was unaffected by site age, but AMF composition variation increased along the chronosequences. AMF communities were unaffected by soil chemistry, but related to the composition of neighboring plant communities of the sampled C. epigejos plants. In contrast, the plant communities of the sites were more distinctively structured than the AMF communities along the four successional stages. We conclude that AMF and plant community successions respond to different factors. AMF communities seem to be influenced by biotic rather than by abiotic factors and to diverge with successional age. PMID:28473828

  15. Richness, diversity and evenness of vegetation upon rehabilitation of gypsum mine spoiled lands in the Indian arid zone

    Science.gov (United States)

    Kumar, S.; Sharma, K.D.; Sharma, U.K.; Gough, L.P.

    1998-01-01

    Richness, diversity and evenness of vegetation, after rehabilitation of gypsum mine spoils at Barmer were investigated in plots protected and planted one year and four years ago. There were four water harvesting treatments, viz., half-moon terraces, micro-catchments with 5% slope, ridge and furrow and control, wherein, indigenous and exotic trees and shrubs were planted at 5 ?? 5 m spacing. Sampling of the planted and natural vegetation, using quadrats and transacts, revealed much less species richness in unplanted control as compared to all treatments and in all the years. The species richness that increased initially (within one year) gradually declined over time (during four year), though the extent varied in different treatments. The water harvesting treatment showing maximum initial increase in richness also showed maximum decline over time, though decline was more in annual species. Two perennial species increased in richness with time. This was further proved from the trends in diversity and evenness indices. It was concluded that natural successional process was accelerated by rehabilitation providing stability to the habitat.

  16. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  17. Mycorrhiza helper bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL

    2016-10-01

    This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

  18. Magnetosome chain superstructure in uncultured magnetotactic bacteria

    International Nuclear Information System (INIS)

    Abraçado, Leida G; Farina, Marcos; Abreu, Fernanda; Keim, Carolina N; Lins, Ulysses; Campos, Andrea P C

    2010-01-01

    Magnetotactic bacteria produce magnetosomes, which are magnetic particles enveloped by biological membranes, in a highly controlled mineralization process. Magnetosomes are used to navigate in magnetic fields by a phenomenon called magnetotaxis. Two levels of organization and control are recognized in magnetosomes. First, magnetotactic bacteria create a spatially distinct environment within vesicles defined by their membranes. In the vesicles, the bacteria control the size, composition and purity of the mineral content of the magnetic particles. Unique crystal morphologies are produced in magnetosomes as a consequence of this bacterial control. Second, magnetotactic bacteria organize the magnetosomes in chains within the cell body. It has been shown in a particular case that the chains are positioned within the cell body in specific locations defined by filamentous cytoskeleton elements. Here, we describe an additional level of organization of the magnetosome chains in uncultured magnetotactic cocci found in marine and freshwater sediments. Electron microscopy analysis of the magnetosome chains using a goniometer showed that the magnetic crystals in both types of bacteria are not oriented at random along the crystal chain. Instead, the magnetosomes have specific orientations relative to the other magnetosomes in the chain. Each crystal is rotated either 60°, 180° or 300° relative to their neighbors along the chain axis, causing the overlapping of the (1 1 1) and (1-bar 1-bar 1-bar) capping faces of neighboring crystals. We suggest that genetic determinants that are not present or active in bacteria with magnetosomes randomly rotated within a chain must be present in bacteria that organize magnetosomes so precisely. This particular organization may also be used as an indicative biosignature of magnetosomes in the study of magnetofossils in the cases where this symmetry is observed

  19. Communication among Oral Bacteria

    Science.gov (United States)

    Kolenbrander, Paul E.; Andersen, Roxanna N.; Blehert, David S.; Egland, Paul G.; Foster, Jamie S.; Palmer, Robert J.

    2002-01-01

    Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities. PMID:12209001

  20. PATHOGENICITY OF BIOFILM BACTERIA

    Science.gov (United States)

    There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

  1. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  2. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030 ...

  3. Phytoremediation of heavy metal contaminated soil potential by woody plants on Tonglushan ancient copper spoil heap in China.

    Science.gov (United States)

    Kang, Wei; Bao, Jianguo; Zheng, Jin; Xu, Fen; Wang, Liuming

    2018-01-02

    Fast-growing metal-accumulating woody plants are considered potential candidates for phytoremediation of metals. Tonglushan mining, one of the biggest Cu production bases in China, presents an important source of the pollution of environment. The sample was collected at Tonglushan ancient copper spoil heap. The aims were to measure the content of heavy metal in the soil and woody plants and to elucidate the phytoremediation potential of the plants. The result showed that soil Cu, Cd and Pb were the main contamination, the mean contents of which were 3166.73 mg/kg, 3.66 mg/kg and 137.06 mg/kg respectively, which belonged to severe contamination. Fourteen species from 14 genera of 13 families were collected and investigated; except for Ligutrum lucidum, the other 13 woody plants species were newly recorded in this area. In addition, to assess the ability of metal accumulation of these trees, we proposed accumulation index. Data suggested that Platanus × acerilolia, Broussonetia papyrifera, Ligutrum lucidum, Viburnum awabuki, Firmiana simplex, Robina pseudoacacia, Melia azedarach and Osmanthus fragrans exhibited high accumulated capacity and strong tolerance to heavy metals. Therefore, Platanus × acerilolia and Broussonetia papyrifera can be planted in Pb contaminated areas; Viburnum awabuki, Firmiana simplex, Robina pseudoacacia and Melia azedarach are the suitable trees for Cd contaminated areas; Viburnum awabuki, Melia azedarach, Ligutrum lucidum, Firmiana simplex, Osmanthus fragrans and Robina pseudoacacia are appropriate to Cu, Pb and Cd multi-metal contaminated areas.

  4. Biosurfactant-producing bacterium, Pseudomonas aeruginosa MA01 isolated from spoiled apples: physicochemical and structural characteristics of isolated biosurfactant.

    Science.gov (United States)

    Abbasi, Habib; Hamedi, Mir Manochehr; Lotfabad, Tayebe Bagheri; Zahiri, Hossein Shahbani; Sharafi, Hakimeh; Masoomi, Fatemeh; Moosavi-Movahedi, Ali Akbar; Ortiz, Antonio; Amanlou, Massoud; Noghabi, Kambiz Akbari

    2012-02-01

    An extensive investigation was conducted to isolate indigenous bacterial strains with outstanding performance for biosurfactant production from different types of spoiled fruits, food-related products and food processing industries. An isolate was selected from 800 by the highest biosurfactant yield in soybean oil medium and it was identified by 16S rRNA and the two most relevant hypervariable regions of this gene; V3 and V6 as Pseudomonas aeruginosa MA01. The isolate was able to produce 12 g/l of a glycolipid-type biosurfactant and generally less efficient to emulsify vegetable oils compared to hydrocarbons and could emulsify corn and coconut oils more than 50%. However, emulsification index (E(24)) of different hydrocarbons including hexane, toluene, xylene, brake oil, kerosene and hexadecane was between 55.8% and 100%. The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mNm(-1) with critical micelle concentration (CMC) value of 10.1mg/l. Among all carbon substrates examined, vegetable oils were the most effective on biosurfactant production. Two glycolipid fractions were purified from the biosurfactant crude extracts, and FTIR and ES-MS were used to determine the structure of these compounds. The analysis indicated the presence of three major monorhamnolipid species: R(1)C(10)C(10), R(1)C(10)C(12:1), and R(1)C(10)C(12); as well as another three major dirhamnolipid species: R(2)C(10)C(10), R(2)C(10)C(12:1), and R(2)C(10)C(12). The strain sweep experiment for measuring the linear viscoelastic of biosurfactant showed that typical behavior characteristics of a weak viscoelastic gel, with storage modulus greater than loss modulus at all frequencies examined, both showing some frequency dependence. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Absolute Quantification of Human Liver Phosphorus-Containing Metabolites In Vivo Using an Inhomogeneous Spoiling Magnetic Field Gradient

    Science.gov (United States)

    Bashir, Adil; Gropler, Robert; Ackerman, Joseph

    2015-01-01

    Purpose Absolute concentrations of high-energy phosphorus (31P) metabolites in liver provide more important insight into physiologic status of liver disease compared to resonance integral ratios. A simple method for measuring absolute concentrations of 31P metabolites in human liver is described. The approach uses surface spoiling inhomogeneous magnetic field gradient to select signal from liver tissue. The technique avoids issues caused by respiratory motion, chemical shift dispersion associated with linear magnetic field gradients, and increased tissue heat deposition due to radiofrequency absorption, especially at high field strength. Methods A method to localize signal from liver was demonstrated using superficial and highly non-uniform magnetic field gradients, which eliminate signal(s) from surface tissue(s) located between the liver and RF coil. A double standard method was implemented to determine absolute 31P metabolite concentrations in vivo. 8 healthy individuals were examined in a 3 T MR scanner. Results Concentrations of metabolites measured in eight healthy individuals are: γ-adenosine triphosphate (ATP) = 2.44 ± 0.21 (mean ± sd) mmol/l of wet tissue volume, α-ATP = 3.2 ± 0.63 mmol/l, β-ATP = 2.98 ± 0.45 mmol/l, inorganic phosphates (Pi) = 1.87 ± 0.25 mmol/l, phosphodiesters (PDE) = 10.62 ± 2.20 mmol/l and phosphomonoesters (PME) = 2.12 ± 0.51 mmol/l. All are in good agreement with literature values. Conclusions The technique offers robust and fast means to localize signal from liver tissue, allows absolute metabolite concentration determination, and avoids problems associated with constant field gradient (linear field variation) localization methods. PMID:26633549

  6. Influence of surface flattening on biodiversity of terrestrial arthropods during early stages of brown coal spoil heap restoration.

    Science.gov (United States)

    Moradi, Jabbar; Potocký, Pavel; Kočárek, Petr; Bartuška, Martin; Tajovský, Karel; Tichánek, Filip; Frouz, Jan; Tropek, Robert

    2018-08-15

    Heterogeneity of environmental conditions is the crucial factor supporting biodiversity in various habitats, including post-mining sites. The effects of micro-topographic heterogeneity on biodiversity and conservation potential of arthropod communities in post-industrial habitats had not been studied before now. At one of the largest European brown coal spoil heaps, we sampled eight groups of terrestrial arthropods with different life strategies (moths, spiders, ground beetles, ants, orthopteroids, centipedes, millipedes, and woodlice), in successionally young plots (5-18 y), with a heterogeneous wavy surface after heaping, and compared the communities with plots flattened by dozing. A combination of the standardized quantitative sampling, using two different methods, and a paired design of the plot selection enabled a robust analysis. Altogether, we recorded 380 species of the focal arthropods, 15 of them nationally threatened. We revealed the importance of the micro-topographic heterogeneity for the formation of the biodiversity of arthropods in their secondary refuges. The communities with higher biodiversity and conservation value were detected in the plots with heterogeneous surfaces; exceptions were ground beetles and millipedes. The surface flattening, often the first step of technical reclamation projects, thus suppress biodiversity of most terrestrial arthropods during the restoration of post-mining sites. Since the communities of both surface types differed, the proportional presence on both surfaces could be more efficient in supporting the local biodiversity. We suggest reducing the surface dozing for the cases with other concerns only, to achieve a proportional representation of both surface types. Such a combination of different restoration approaches would, thus, efficiently support high biodiversity of groups with various needs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Mycorrhizal status of plants in two successional stages on spoil heaps from fireloam mining in Lower Silesia (SW Poland

    Directory of Open Access Journals (Sweden)

    Dorota Kasowska

    2014-01-01

    Full Text Available The mycorrhizal status of two plant communities representing an initial stage (1-2 year-old and a 8-9-year-old stage of succession on spoil heaps from fireloam mining in Lower Silesia, Poland, was determined. In the initial stage, the mycorrhizal structures were not observed in 39% of the investigated species; they were members of the Polygonaceae, Chenopodiaceae and Poaceae families. The relative cover of non-mycorrhizal plants exceeded 50% and the major role was played by the Polygonum aviculare population, which predominated the whole community. Mycorrhizal species (arbuscular mycorrhizae contributed to 61 % of the composition of the initial phyto-coenosis. The most numerous taxa were those with 20-40% of the root length colonized, with a small number of arbuscules (0.2-3.1% of the root length containig arbuscules and no vesicles. In the advanced stage of succession, mycorrhizal plants definitely dominated and the major role was played by the Tussilago farfara population. Compared with the initial stage, the later one also harboured more plants with mycorrhizas occupied >40% of the root length, as well as containing numerous arbuscules (>20% of the root length and vesicles. The non-mycorrhizal species, i.e., Equisetum arvense and Poa compressa, represented 11 % o': the community composition and their relative cover amounted to 3%. Despite the relatively frequent occurrence of the arbuscular mycorrhizae in the initial stage of succession, the qualitative properties of the colonization indicated a low effectiveness of symbiosis. This could be caused by the lack of adaptation of the fungal symbiont to the edaphic conditions which were changed after disturbance.

  8. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 from HT-29 cells · Lactobacillus GG prevents the IL-8 release in response to pathogens · Effect of probiotic bacteria on chemokine response of epithelia to pathogens · PCR array studies in colon ...

  9. Soil organic carbon and nitrogen accumulation on coal mine spoils reclaimed with maritime pine (Pinus pinaster Aiton) in Agacli-Istanbul.

    Science.gov (United States)

    Sever, Hakan; Makineci, Ender

    2009-08-01

    Mining operations on open coal mines in Agacli-Istanbul have resulted in the destruction of vast amounts of land. To rehabilitate these degraded lands, plantations on this area began in 1988. Twelve tree species were planted, however, the most planted tree species was maritime pine (Pinus pinaster Aiton). This study performed on 14 sample plots randomly selected in maritime pine plantations on coal mine soil/spoils in 2005. Soil samples were taken from eight different soil layers (0-1, 1-3, 3-5, 5-10, 10-20, 20-30, 30-40 and 40-50 cm) into the soil profile. On soil samples; fine soil fraction (<2 mm), soil acidity (pH), organic carbon (C(org)) and total nitrogen (N(t)) contents were investigated, and results were compared statistically among soil layers. As a result, 17 years after plantations, total forest floor accumulation determined as 17,973.20 kg ha(-1). Total nitrogen and organic matter amounts of forest floor were 113.90 and 14,640.92 kg ha(-1) respectively. Among soil layers, the highest levels of organic carbon (1.77%) and total nitrogen (0.096%) and the lowest pH value (pH 5.38) were found in 0-1 cm soil layer, and the variation differs significantly among soil layers. Both organic carbon and total nitrogen content decreased, pH values increased from 0-1 to 5-10 cm layer. In conclusion, according to results obtained maritime pine plantations on coal mine spoils; slow accumulation and decomposition of forest floor undergo simultaneously. Depending on these changes organic carbon and total nitrogen contents increased in upper layer of soil/spoil.

  10. Reestablishment of woody plants on mine spoils and management of mine water impoundments: an overview of Forest Service research on the northern High Plain

    Energy Technology Data Exchange (ETDEWEB)

    Bjugstad, A J

    1977-01-01

    The function of the research unit at Rapid city, S. Dakota, is to provide guidelines for the reestablisment of shrubs and trees on land characteristic of the High Plains, and for the mitigation of possible detrimental effects of surface mining on ground water and surface water. One possible problem posed by surface mining concerns the formation of land drainage patterns that could result in post-mining formations of large salt playas. Surface mining could affect shallow ground water aquifers up to /sup 1///sub 4/ mile from the mine site. Research is being conducted on the reclamation of mine spoils and on the rehabilitation and management of impounded mine water.

  11. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  12. Motility of magnetotactic bacteria/MTB to Geomagnetic fields

    Science.gov (United States)

    Hidajatullah-Maksoed, Fatahillah

    2016-03-01

    Bacteria with motility directed by a local geomagnetic fields have been observed in marine sediments'' discussed by R. Blakemore, 1975. Magnetotactic bacteria/MTB discovered in 1963 by Salvatore Bellini. For ``off-axis electron holography in the transmission electron microscope was used to correlates the physical & magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria'' sought ``single-domain magnetite in hemopelagic sediments'' from JF Stolz. Otherwise, for potential source of bioproducts- product meant from result to multiplier -of magnetotactic bacteria[ACV Araujo, et.al, 2014 ] of marine drugs retrieved the `measurement of cellular chemotaxis with ECIS/Taxis, from KM Pietrosimone, 2012, whereas after ``earth magnetic field role on small living models'' are other interpretation of ``taxis'' as a movement of a cell instead usual ``tax'' for yew's taxus cuspidate, hired car & taxes in financial realms. Acknowledgements to HE. Mr. H. TUK SETYOHADI, Jl. Sriwijaya Raya 3, South-Jakarta, INDONESIA.

  13. Rapid diagnostics of the bacteria in air

    Energy Technology Data Exchange (ETDEWEB)

    Belov Nikolai, N. [ATECH KFT, Budapest (Hungary)

    2000-07-01

    ) Diagnostics of vital microorganisms in aerosol samples by ATF reaction. This is modification of ATF measurement of bacteria for aerosol problems. This method helps us to count quality of bacteria in air in real time of measurement. Each bacterium is opened on the transparent bottom by special chemistry reagent. Bioluminescence during ATF-reaction with content of bacterium provides us information about alive material in the aerosol sample. (3) Phase microscope for bio-aerosol diagnostics helps us to achieve the resolution of electronic microscope with optical system. It is very important that our microscope is not disturbing the alive material. So motions of the parts of bacteria will help us to find it on the bio-sampler plate. More over frequencies of these moving with provide us additional information about microorganisms. Phase microscope will show you growth of bacterial colony with resolution {approx} 100 nanometers. (4) Diagnostics of polynucleotides in samples of aerosol (airborne) may be used for full analysis of interested microorganism on the bio-sampler plate. Reproducing of the great number DNA molecules from DNA of bacterium provides us excellent material for selection of dangerous bacteria. So our results provides possibility of quasi-real time measurement of the bacteria in the air. (author)

  14. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  15. Electron Microscopic Analysis and Structural Characterization of Novel NADP(H)-Containing Methanol : N,N'-Dimethyl-4-Nitrosoaniline Oxidoreductases from the Gram-Positive Methylotrophic Bacteria Amycolatopsis methanolica and Mycobacterium gastri MB19

    NARCIS (Netherlands)

    Bystrykh, Leonid V.; Vonck, Janet; Bruggen, Ernst F.J. van; Beeumen, Jozef van; Samyn, Bart; Govorukhina, Natalya I.; Arfman, Nico; Duine, Johannis A.; Dijkhuizen, Lubbert

    The quaternary protein structure of two methanol:N,N'-dimethyl-4-nitrosoaniline (NDMA) oxidoreductases purified from Amycolatopsis methanolica and Mycobacterium gastri MB19 was analyzed by electron microscopy and image processing. The enzymes are decameric proteins (displaying fivefold symmetry)

  16. Material and method for promoting the growth of anaerobic bacteria

    Science.gov (United States)

    Adler, Howard I.

    1984-01-01

    A material and method for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10.degree. to about 60.degree. C. until the dissolved oxygen is removed.

  17. An experimental study on dredge spoil of estuarine sediments in the bay of seine (France): A morphosedimentary assessment

    Science.gov (United States)

    Marmin, Stella; Lesueur, Patrick; Dauvin, Jean Claude; Samson, Sandrine; Tournier, Patrice; Gallicher Lavanne, Albert; Dubrulle-Brunaud, Carole; Thouroude, Coralie

    2016-03-01

    Studies on the consequences of dredging on estuarine morphology and its sedimentary dynamics are common, but the impacts of dumping dredge spoil in coastal open settings are rarely found in scientific literature. An experimental study was conducted over the period 2012-2013 to monitor the physical impacts of dredged material dumped at two adjacent sites (one million cubic metres at each) on the inner shelf of the Bay of Seine in France (eastern part of the English Channel, La Manche). As recently reinforced in the EU Marine Strategy Framework Directive (MSFD), knowledge on the location and intensity of human impacts (e.g. on marine ecosystems) is critical for effective marine management and conservation. So, two methods of disposition were tested to evaluate the impacts of dumping on the environment and thus propose recommendations for future dumping. The strategy is based on a Before-After-Control-Impact (BACI) approach, in which the spatio-temporal variability was studied by analysing the morphological and sedimentological characteristics over a period of 28 months, from November 2011 to April 2014, also including recovery of the seafloor after cessation of the dumping activities. The first experimental dumping operation (MASED) was carried out regularly for 8 months at a single point and generating a conical deposit of 5 m in height, while the second dumping (MABIO) lasted for 12 months involving four steps in the dumping process. In the second case, a wider area was covered, leading to the formation of a smaller deposit of 2 m in height. The dumped deposits consisted of muddy fine sand, whereas the inner shelf seafloor in this area is covered with fine to medium sand. As a result, muddy fine sand accumulated at or near the two dumping sites, with a maximum mud (i.e. particles4 Φ) content of 50% compared todredged material remained at the end of the dumping periods. After dumping ceased, a further 5% of material for MABIO and 20% for MASED, was transported out

  18. Characteristics of N-Acylhomoserine Lactones Produced by Hafnia alvei H4 Isolated from Spoiled Instant Sea Cucumber

    Directory of Open Access Journals (Sweden)

    Hong-Man Hou

    2017-04-01

    Full Text Available This study aimed to identify N-acylhomoserine lactone (AHL produced by Hafnia alvei H4, which was isolated from spoiled instant sea cucumber, and to investigate the effect of AHLs on biofilm formation. Two biosensor strains, Chromobacterium violaceum CV026 and Agrobacterium tumefaciens KYC55, were used to detect the quorum sensing (QS activity of H. alvei H4 and to confirm the existence of AHL-mediated QS system. Thin layer chromatography (TLC and high resolution triple quadrupole liquid chromatography/mass spectrometry (LC/MS analysis of the AHLs extracted from the culture supernatant of H. alvei H4 revealed the existence of at least three AHLs: N-hexanoyl-l-homoserine lactone (C6-HSL, N-(3-oxo-octanoyl-l-homoserine lactone (3-oxo-C8-HSL, and N-butyryl-l-homoserine lactone (C4-HSL. This is the first report of the production of C4-HSL by H. alvei. In order to determine the relationship between the production of AHL by H. alvei H4 and bacterial growth, the β-galactosidase assay was employed to monitor AHL activity during a 48-h growth phase. AHLs production reached a maximum level of 134.6 Miller unites at late log phase (after 18 h and then decreased to a stable level of about 100 Miller unites. AHL production and bacterial growth displayed a similar trend, suggesting that growth of H. alvei H4 might be regulated by QS. The effect of AHLs on biofilm formation of H. alvei H4 was investigated by adding exogenous AHLs (C4-HSL, C6-HSL and 3-oxo-C8-HSL to H. alvei H4 culture. Biofilm formation was significantly promoted (p < 0.05 by 5 and 10 µM C6-HSL, inhibited (p < 0.05 by C4-HSL (5 and 10 µM and 5 µM 3-oxo-C8-HSL, suggesting that QS may have a regulatory role in the biofilm formation of H. alvei H4.

  19. Effect of Ionizing Radiation on Luminous Bacteria Cells

    International Nuclear Information System (INIS)

    Kudryasheva, N.; Rozhko, T.; Alexandrova, M.; Vasyunkina, E.; Arkhipova, V.

    2011-01-01

    Marine luminous bacteria were used to monitor toxicity of alpha- (Am-241, U-235+238) and beta- (tritium) radionuclide solutions. Increase or inhibition of bacterial luminescence was observed under exposure to radionuclides. Radiation toxicity of Am and chemical toxicity of U were demonstrated. Effects of U were similar to those of stable heavy metals: sensitivity was about 10-5 M. Sensitivity of the bacteria to Am-241 was 300 Bq/L (10 -11 M). Inhibition of bacterial growth was observed under exposure to Am-241 and tritium. Role of peroxides and electron transfer processes in the effects of radionuclides on luminous bacteria is discussed.

  20. Isolation and characterization of autotrophic, hydrogen-utilizing, perchlorate-reducing bacteria.

    Science.gov (United States)

    Shrout, Joshua D; Scheetz, Todd E; Casavant, Thomas L; Parkin, Gene F

    2005-04-01

    Recent studies have shown that perchlorate (ClO(4) (-)) can be degraded by some pure-culture and mixed-culture bacteria with the addition of hydrogen. This paper describes the isolation of two hydrogen-utilizing perchlorate-degrading bacteria capable of using inorganic carbon for growth. These autotrophic bacteria are within the genus Dechloromonas and are the first Dechloromonas species that are microaerophilic and incapable of growth at atmospheric oxygen concentrations. Dechloromonas sp. JDS5 and Dechloromonas sp. JDS6 are the first perchlorate-degrading autotrophs isolated from a perchlorate-contaminated site. Measured hydrogen thresholds were higher than for other environmentally significant, hydrogen-utilizing, anaerobic bacteria (e.g., halorespirers). The chlorite dismutase activity of these bacteria was greater for autotrophically grown cells than for cells grown heterotrophically on lactate. These bacteria used fumarate as an alternate electron acceptor, which is the first report of growth on an organic electron acceptor by perchlorate-reducing bacteria.

  1. Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

    Energy Technology Data Exchange (ETDEWEB)

    Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

    2010-04-15

    Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

  2. Intentional introduction of Biscutella laevigata L. on the post-flotation lead-zinc ore spoil heap in Piekary Śląskie (Upper Silesia, Southern Poland

    Directory of Open Access Journals (Sweden)

    Rostański Adam

    2014-09-01

    Full Text Available The paper presents an account of the successful intentional introduction of the mountain species Biscutella laevigata to a lowland locality, as a result of field experiment - biological management at the toxic “Dołki” washery spoil heap (Lead and Zinc Ore Main and Factory ZGH “Orzeł Biały” (Upper Silesia – Southern Poland. The aim of the presented study was to test the effectiveness possibilities of using the blend of seeds including a metallophyte – Biscutella laevigata seeds. The introduction of Biscutella laevigata was a part of an experiment which began in 2009-2010 with plots on the "Dolki" washery spoil heap. The tested seeds of Biscutella laevigata were examined for germination, growth and development in sites highly polluted with heavy metals. Biscutella laevigata appeared on two experimental plots. After 4 years there were numerous individuals of Biscutella – dozens of plants in various stages of development and phenology. Development of a Biscutella population from year to year (2 plants in 2010 – 58 plants in 2014 is larger and tends to increase. Biscutella individuals are spreading outside the designated test plots. The obtained results indicate that on sites highly polluted with heavy metals it is possible to perform a successful introduction of Biscutella laevgata population (increase from 2 individuals in 2010 to 58 individuals in 2014 from seeds. These results are also promising in terms of application as a new reclamation method.

  3. Possibilities for production of medicinal aromatic plants on the spoil bank of the Pljevlja coal mine. Mogucnost gajenja ljekovitog i aromaticnog bilja na jalovistu rudnika uglja - Pljevlja

    Energy Technology Data Exchange (ETDEWEB)

    Memic, M.; Bajovic, L. (Rudnik Uglja Pljevlja (Yugoslavia))

    1990-01-01

    Presents results obtained from experimental recultivation of the Potrlica surface coal mine spoil bank (810 m elevation, continental climate) during 1986-1990. Two experimental fields - Potrlica-I (600 m[sup 2]) and Potrlica-II (300 m[sup 2]) - were prepared by spreading a 10-20 cm thick layer of low-quality soil over the marly waste of the spoil bank. Soil composition was: 2.10% and 74% Ca, 4.5% and 0.70% humus, l3.5% and 5.5% P[sub 2]O[sub 5] and 23.0% and 6.0% K[sub 2]O in Potrlica-I and II respectively. Soil pH values were 7.2 and 7.60; 500 kg/ha NPK (15:15:15) were spread. Seventeen species of aromatic and medicinal plants were grown. After four years the plants were classified into 3 groups (thriving, satisfactory and non-thriving). It was found that the following plants can yield satisfactory crops and profits: valeriana officinalis, hyssopus officinalis, artemis dracunculus, cynaris scolimus, foenculum vulgare and malva silvestris. Unsatisfactory results were obtained with melisa officinalis, coriandrum sativum, pimpinela anisum and angelica archangelica. Experiments will be continued.

  4. Restoration Practices Used on Post Mining Sites and Industrial Deposits in the Czech Republic with an Example of Natural Restoration of Granodiorite Quarries and Spoil Heaps

    Directory of Open Access Journals (Sweden)

    Chuman Tomáš

    2015-11-01

    Full Text Available Mining of minerals that have significant impact on landscape and landscape functions affects 1% of the land surface worldwide. In the Czech Republic the extent of mining sites is estimated to be more than 800 km2 and according to the state legislation the land affected by mining should be reclaimed. There are several approaches to land restoration, which are shortly reviewed in this article, from pure technical approach to one adopting natural processes. The review shows increasing appeal of scientist and conservationist to use natural processes e.g. natural or directed succession as an alternative method of post-mining sites or industrial deposits restoration due to growing evidence of conservational value of such sites in human dominated landscapes. The natural processes used for land restoration are often argued to be slow therefore the rate of spontaneous vegetation succession was assessed in stone quarries and on spoil heaps using a sequence of panchromatic aerial images. The results showed that natural processes act fast and vegetation can reach 100% cover within 10-15 years in granodiorite quarries and on spoil heaps.

  5. Homogeneity spoil spectroscopy

    International Nuclear Information System (INIS)

    Hennig, J.; Boesch, C.; Martin, E.; Grutter, R.

    1987-01-01

    One of the problems of in vivo MR spectroscopy of P-31 is spectra localization. Surface coil spectroscopy, which is the method of choice for clinical applications, suffers from the high-intensity signal from subcutaneous muscle tissue, which masks the spectrum of interest from deeper structures. In order to suppress this signal while maintaining the simplicity of surface coil spectroscopy, the authors introduced a small sheet of ferromagnetically dotted plastic between the surface coil and the body. This sheet destroys locally the field homogeneity and therefore all signal from structures around the coil. The very high reproducibility of the simple experimental procedure allows long-term studies important for monitoring tumor therapy

  6. Functional amyloids in bacteria.

    Science.gov (United States)

    Romero, Diego; Kolter, Roberto

    2014-06-01

    The term amyloidosis is used to refer to a family of pathologies altering the homeostasis of human organs. Despite having a name that alludes to starch content, the amyloid accumulations are made up of proteins that polymerize as long and rigid fibers. Amyloid proteins vary widely with respect to their amino acid sequences but they share similarities in their quaternary structure; the amyloid fibers are enriched in β-sheets arranged perpendicular to the axis of the fiber. This structural feature provides great robustness, remarkable stability, and insolubility. In addition, amyloid proteins specifically stain with certain dyes such as Congo red and thioflavin-T. The aggregation into amyloid fibers, however, it is not restricted to pathogenic processes, rather it seems to be widely distributed among proteins and polypeptides. Amyloid fibers are present in insects, fungi and bacteria, and they are important in maintaining the homeostasis of the organism. Such findings have motivated the use of the term "functional amyloid" to differentiate these amyloid proteins from their toxic siblings. This review focuses on systems that have evolved in bacteria that control the expression and assembly of amyloid proteins on cell surfaces, such that the robustness of amyloid proteins are used towards a beneficial end. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  7. The interaction of bacteria and metal surfaces

    International Nuclear Information System (INIS)

    Mansfeld, Florian

    2007-01-01

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E corr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)-current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions

  8. The interaction of bacteria and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mansfeld, Florian [Corrosion and Environmental Effects Laboratory (CEEL), The Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241 (United States)

    2007-10-10

    This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates ('microbiologically influenced corrosion' (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential E{sub corr} became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V) - current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. (author)

  9. Spoilage of vegetable crops by bacteria and fungi and related health hazards.

    Science.gov (United States)

    Tournas, V H

    2005-01-01

    After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. The most common bacterial agents are Erwinia carotovora, Pseudomonas spp., Corynebacterium, Xanthomonas campestris, and lactic acid bacteria with E. carotovora being the most common, attacking virtually every vegetable type. Fungi commonly causing spoilage of fresh vegetables are Botrytis cinerea, various species of the genera Alternaria, Aspergillus, Cladosporium, Colletotrichum, Phomopsis, Fusarium, Penicillium, Phoma, Phytophthora, Pythium and Rhizopus spp., Botrytis cinerea, Ceratocystis fimbriata, Rhizoctonia solani, Sclerotinia sclerotiorum, and some mildews. A few of these organisms show a substrate preference whereas others such as Botrytis cinerea, Colletotrichum, Alternaria, Cladosporium, Phytophthora, and Rhizopus spp., affect a wide variety of vegetables causing devastating losses. Many of these agents enter the plant tissue through mechanical or chilling injuries, or after the skin barrier has been broken down by other organisms. Besides causing huge economic losses, some fungal species could produce toxic metabolites in the affected sites, constituting a potential health hazard for humans. Additionally, vegetables have often served as vehicles for pathogenic bacteria, viruses, and parasites and were implicated in many food borne illness outbreaks. In order to slow down vegetable spoilage and minimize the associated adverse health effects, great caution should be taken to follow strict hygiene, good agricultural practices (GAPs) and good manufacturing practices (GMPs) during cultivation, harvest, storage, transport, and marketing.

  10. Lactic Acid Bacteria Selection for Biopreservation as a Part of Hurdle Technology Approach Applied on Seafood

    Directory of Open Access Journals (Sweden)

    Norman Wiernasz

    2017-05-01

    Full Text Available As fragile food commodities, microbial, and organoleptic qualities of fishery and seafood can quickly deteriorate. In this context, microbial quality and security improvement during the whole food processing chain (from catch to plate, using hurdle technology, a combination of mild preserving technologies such as biopreservation, modified atmosphere packaging, and superchilling, are of great interest. As natural flora and antimicrobial metabolites producers, lactic acid bacteria (LAB are commonly studied for food biopreservation. Thirty-five LAB known to possess interesting antimicrobial activity were selected for their potential application as bioprotective agents as a part of hurdle technology applied to fishery products. The selection approach was based on seven criteria including antimicrobial activity, alteration potential, tolerance to chitosan coating, and superchilling process, cross inhibition, biogenic amines production (histamine, tyramine, and antibiotics resistance. Antimicrobial activity was assessed against six common spoiling bacteria in fishery products (Shewanella baltica, Photobacterium phosphoreum, Brochothrix thermosphacta, Lactobacillus sakei, Hafnia alvei, Serratia proteamaculans and one pathogenic bacterium (Listeria monocytogenes in co-culture inhibitory assays miniaturized in 96-well microtiter plates. Antimicrobial activity and spoilage evaluation, both performed in cod and salmon juice, highlighted the existence of sensory signatures and inhibition profiles, which seem to be species related. Finally, six LAB with no unusual antibiotics resistance profile nor histamine production ability were selected as bioprotective agents for further in situ inhibitory assays in cod and salmon based products, alone or in combination with other hurdles (chitosan, modified atmosphere packing, and superchilling.

  11. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  12. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  13. Fermentative Bacteria Influence the Competition between Denitrifiers and DNRA Bacteria

    Directory of Open Access Journals (Sweden)

    Eveline M. van den Berg

    2017-09-01

    results of this study clearly show that not only the ratio of available substrates, but also the nature of the electron donor influences the outcome of competition between DNRA and denitrification. Apparently, fermentative bacteria are competitive for the electron donor and thereby alter the ratio of available substrates for nitrate reduction.

  14. Radiation-resistant asporogenic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yano, K [Tokyo Univ. (Japan). Faculty of Agriculture

    1975-09-01

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned.

  15. Radiation-resistant asporogenic bacteria

    International Nuclear Information System (INIS)

    Yano, Keiji

    1975-01-01

    This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned. (Tsukamoto, Y.)

  16. Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

    International Nuclear Information System (INIS)

    Malkin, A.J.

    2010-01-01

    The extraordinary ability of indigenous microorganisms, like metal-resistant bacteria, for biotransformation of toxic compounds is of considerable interest for the emerging area of environmental bioremediation. However, the underlying mechanisms by which metal-resistant bacteria transform toxic compounds are currently unknown and await elucidation. The project's objective was to study stress-induced responses of metal-resistant bacteria to environmental changes and chemical stimulants. This project involved a multi-institutional collaboration of our LLNL group with the group of Dr. H.-Y. Holman (Lawrence Berkeley National Laboratory). In this project, we have utilized metal-resistant bacteria Arthrobacter oxydans as a model bacterial system. We have utilized atomic force microscopy (AFM) to visualize for the first time at the nanometer scale formation of stress-induced structures on bacterial surfaces in response to Cr (VI) exposure. We have demonstrated that structure, assembly, and composition of these stress-induced structures are dependent on Cr (VI) concentrations. Our AFM observations of the appearance and development of stress-induced layers on the surfaces of Arthrobacter oxydans bacteria exposed to Cr (VI) were confirmed by Dr. Holman's biochemical, electron microscopy, and synchrotron infrared spectromicroscopy studies. In general, in vitro imaging of live microbial and cellular systems represents one of the most challenging issues in application of AFM. Various approaches for immobilization of bacteria on the substrate for in vitro imaging were tested in this project. Imaging of live bacteria was achieved, however further optimization of experimental methods are needed for high-resolution visualization of the cellular environmental structural dynamics by AFM. This project enhanced the current insight into molecular architecture, structural and environmental variability of bacterial systems. The project partially funded research for two book chapters (1

  17. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  18. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  19. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  20. Electroactive biofilms of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Cordas, Cristina M.; Guerra, L. Tiago; Xavier, Catarina; Moura, Jose J.G.

    2008-01-01

    Biofilms formed from a pure strain of Desulfovibrio desulfuricans 27774 on stainless steel and graphite polarised surfaces were studied. The polarisation conditions applied were -0.4 V vs. SCE for different times. A cathodic current related with the biofilms growth was observed with a maximum intensity of -270 mA m -2 that remained stable for several days using graphite electrodes. These sulphate reducing bacteria biofilms present electrocatalytic activity towards hydrogen and oxygen reduction reactions. Electrode polarisation has a selective effect on the catalytic activity. The biofilms were also observed by scanning electronic microscopy revealing the formation of homogeneous films on the surfaces

  1. Electroactive biofilms of sulphate reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cordas, Cristina M.; Guerra, L. Tiago; Xavier, Catarina [Requimte-CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Moura, Jose J.G. [Requimte-CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)], E-mail: jose.moura@dq.fct.unl.pt

    2008-12-01

    Biofilms formed from a pure strain of Desulfovibrio desulfuricans 27774 on stainless steel and graphite polarised surfaces were studied. The polarisation conditions applied were -0.4 V vs. SCE for different times. A cathodic current related with the biofilms growth was observed with a maximum intensity of -270 mA m{sup -2} that remained stable for several days using graphite electrodes. These sulphate reducing bacteria biofilms present electrocatalytic activity towards hydrogen and oxygen reduction reactions. Electrode polarisation has a selective effect on the catalytic activity. The biofilms were also observed by scanning electronic microscopy revealing the formation of homogeneous films on the surfaces.

  2. Disinfection of bacteria attached to granular activated carbon.

    Science.gov (United States)

    LeChevallier, M W; Hassenauer, T S; Camper, A K; McFeters, G A

    1984-01-01

    Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected with 2.0 mg of chlorine per liter (1.4 to 1.6 mg of free chlorine residual per liter after 1 h) for 1 h, no significant decrease in viable counts was observed. Washed cells attached to the surface of granular activated carbon particles showed similar resistance to chlorine, but a progressive increase in sublethal injury was found. Observations made by scanning electron microscope indicated that granular activated carbon was colonized by bacteria which grow in cracks and crevices and are coated by an extracellular slime layer. These data suggest a possible mechanism by which treatment and disinfection barriers can be penetrated and pathogenic bacteria may enter drinking water supplies. Images PMID:6508306

  3. Optimization of three-dimensional triple IR fast spoiled gradient recalled acquisition in the steady state (FSPGR) to decrease vascular artifact at 3.0 Tesla

    International Nuclear Information System (INIS)

    Fujiwara, Yasuhiro; Fukuya, Yuko; Yamaguchi, Isao; Matsuda, Tsuyoshi; Ishimori, Yoshiyuki; Yamada, Kazuhiro; Kimura, Hirohiko; Miyati, Tosiaki

    2006-01-01

    The purpose of this study was to decrease vascular artifacts caused by the in-flow effect in three-dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady state (3D IR FSPGR) at 3.0 Tesla. We developed 3D triple IR (3IR) FSPGR and examined the signal characteristics of the new sequence. We have optimized scan parameters based on simulation, phantom, and in-vivo studies. As a result, optimized parameters (1st TI=600 ms, 3rd TI=500 ms) successfully have produced the vessel signal at more than 40% reduction, while gray-white matter contrast was preserved. Moreover, the reduced artifact was also confirmed by visual inspection of the in-vivo images for which this condition was used. Thus, 3D 3IR FSPGR was a useful sequence for the acquisition of T1-weighted images at 3.0 Tesla. (author)

  4. Money and transmission of bacteria.

    NARCIS (Netherlands)

    Gedik, H.; Voss, T.A.; Voss, A.

    2013-01-01

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria

  5. METHODS FOR DETECTING BACTERIA USING POLYMER MATERIALS

    NARCIS (Netherlands)

    Van Grinsven Bart Robert, Nicolaas; Cleij, Thomas

    2017-01-01

    A method for characterizing bacteria includes passing a liquid containing an analyte comprising a first bacteria and a second bacteria over and in contact with a polymer material on a substrate. The polymer material is formulated to bind to the first bacteria, and the first bacteria binds to the

  6. The anammoxosome: an intracytoplasmic compartment in anammox bacteria

    NARCIS (Netherlands)

    Niftrik, L.A.M.P. van; Fuerst, J.A.; Damste, J.S.S.; Kuenen, J.G.; Jetten, M.S.M.; Strous, M.

    2004-01-01

    Anammox bacteria belong to the phylum Planctomycetes and perform anaerobic ammonium oxidation (anammox); they oxidize ammonium with nitrite as the electron acceptor to yield dinitrogen gas. The anammox reaction takes place inside the anammoxosome: an intracytoplasmic compartment bounded by a single

  7. The anammoxosome : An intracytoplasmic compartment in anammox bacteria

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Niftrik, L.A. van; Fuerst, J.A.; Kuenen, J.G.; Jetten, M.S.M.; Strous, M.

    2004-01-01

    Anammox bacteria belong to the phylum Planctomycetes and perform anaerobic ammonium oxidation (anammox); they oxidize ammonium with nitrite as the electron acceptor to yield dinitrogen gas. The anammox reaction takes place inside the anammoxosome: an intracytoplasmic compartment bounded by a single

  8. Iron minerals formed by dissimilatory iron-and sulfur reducing bacteria studied by Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Chistyakova, N. I.; Rusakov, V. S.; Nazarova, K. A.; Koksharov, Yu. A.; Zavarzina, D. G.; Greneche, J.-M.

    2008-01-01

    Zero-field and in-field Moessbauer investigations and electron paramagnetic resonance (EPR) measurements to follow the kinetics of the iron mineral formation by thermophilic dissimilatory anaerobic Fe(III)-reducing bacteria (strain Z-0001) and anaerobic alkaliphilic bacteria (strain Z-0531) were carried out.

  9. Review on SERS of Bacteria

    Directory of Open Access Journals (Sweden)

    Pamela A. Mosier-Boss

    2017-11-01

    Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

  10. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  11. Antibacterial Activities of Endophytic Bacteria Isolated from Taxus brevifolia Against Foodborne Pathogenic Bacteria.

    Science.gov (United States)

    Islam, Nurul; Choi, Jaehyuk; Baek, Kwang-Hyun

    2018-05-01

    Endophytes are a potential source of novel bioactive compounds with medicinal properties. In this study, 41 endophytic bacteria (EB) were isolated from tissues of a medicinally important plant Taxus brevifolia (Pacific yew). The objective was to screen all the EB isolates for their antibacterial effects against five foodborne pathogenic bacteria: Bacillus cereus ATCC10876, Staphylococcus aureus ATCC12600, Listeria monocytogenes ATCC19115, Escherichia coli ATCC43890, and Salmonella Typhimurium ATCC19585. Among the EB isolates, T. brevifolia seed (TbS)-8, T. brevifolia fleshy part of fruit (TbFl)-10, T. brevifolia leaf (TbL)-22, TbS-29, and TbL-34 exerted significant antibacterial activity against the tested foodborne pathogens. Especially TbFl-10 showed the highest antibacterial activity against all the tested bacteria and was identified as Paenibacillus kribbensis (Pk). Furthermore, an ethyl acetate extract of Pk-TbFl-10 possessed antibacterial activities against the tested five foodborne pathogenic bacteria, with zones of inhibition from 15.71 ± 2.85 to 13.01 ± 2.12 mm. Scanning electron microscopy analysis revealed ruptured, lysed, shrunk, and swollen cells of all the tested foodborne pathogens treated with the ethyl acetate extract of Pk-TbFl-10, suggesting that a metabolite(s) of Pk-TbFl-10 penetrates the cell membrane and causes cell lysis leading to cell death. Our results indicate that Pk-TbFl-10 isolated from T. brevifolia can serve as a novel source of natural antibacterial agents against foodborne pathogenic bacteria, with potential applications in the pharmaceutical industry.

  12. Gut Bacteria Affect Immunotherapy Response

    Science.gov (United States)

    Three new studies have identified intestinal bacteria that appear to influence the response to checkpoint inhibitors. This Cancer Currents blog post explains how the researchers think their findings could be used to improve patients’ responses to these immunotherapy drugs.

  13. hydroxyalkanoate (PHAs) producing bacteria isolated

    African Journals Online (AJOL)

    SERVER

    2007-07-04

    Jul 4, 2007 ... ium (MSM), having inhibitors for Gram positive bacteria and fungi and a mixed ... Two techniques were used for detecting the presence of polymer: staining ... was saline solution at 600 nm wavelength on VARIAN DSM 100.

  14. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  15. Anaerobic bacteria that dechlorinate perchloroethene.

    Science.gov (United States)

    Fathepure, B Z; Nengu, J P; Boyd, S A

    1987-01-01

    In this study, we identified specific cultures of anaerobic bacteria that dechlorinate perchlorethene (PCE). The bacteria that significantly dechlorinated PCE were strain DCB-1, an obligate anaerobe previously shown to dechlorinate chlorobenzoate, and two strains of Methanosarcina. The rate of PCE dechlorination by DCB-1 compared favorably with reported rates of trichloroethene bio-oxidation by methanotrophs. Even higher PCE dechlorination rates were achieved when DCB-1 was grown in a methanogenic consortium. PMID:3426224

  16. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  17. Lignin distribution in waterlogged archaeological Picea abies (L.) Karst degraded by erosion bacteria

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard; Schmitt, Uwe Schmitt; Koch, Gerald

    2014-01-01

    The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV-microspectrophotome......The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV...

  18. Counter-measures to reduce the effects of spoil tips on the quality of ground water-standard-setting boundary conditions and implementation; Gegenmassnahmen zur Verminderung der Auswirkungen von Abraumkippen auf die Grundwasserbeschaffenheit. Normative Rahmenbedingungen und Umsetzung

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, Nils [Erfverband, Bergheim (Germany). Abt. Grundwasser; Bolle, Christian [Ministerium fuer Wirtschaft, Energie, Bauen, Wohnen und Verkehr des Landes Nordrhein-Westfalen, Duesseldorf (Germany)

    2010-10-15

    The lignite mining industry in North Rhine-Westphalia gives rise to large spoil tips because of the mining methods. In the Rhenish lignite districts spoil quantities of over 30 bn m{sup 3} will accumulate in tips covering a total area of 300 km{sup 2} by the end of open-cast mining in the 2040s. It is important to counteract by suitable measures the effects of these waste tips, which are characterised essentially by pyrite oxidation, on the future quality of ground water after its renewed rise. This contribution describes the counter-measures already used for some time to reduce the effects on the ground water quality both from standard-setting, chemical and technical points of view. Furthermore the effectiveness of the measures described and thus the contribution to ground water protection and also to safeguard of the water supply can be specified. (orig.)

  19. Human body may produce bacteria.

    Science.gov (United States)

    Salerian, Alen J

    2017-06-01

    "Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Horizontal gene transfer between bacteria.

    Science.gov (United States)

    Heuer, Holger; Smalla, Kornelia

    2007-01-01

    Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

  1. Mechanistic modeling of biocorrosion caused by biofilms of sulfate reducing bacteria and acid producing bacteria.

    Science.gov (United States)

    Xu, Dake; Li, Yingchao; Gu, Tingyue

    2016-08-01

    Biocorrosion is also known as microbiologically influenced corrosion (MIC). Most anaerobic MIC cases can be classified into two major types. Type I MIC involves non-oxygen oxidants such as sulfate and nitrate that require biocatalysis for their reduction in the cytoplasm of microbes such as sulfate reducing bacteria (SRB) and nitrate reducing bacteria (NRB). This means that the extracellular electrons from the oxidation of metal such as iron must be transported across cell walls into the cytoplasm. Type II MIC involves oxidants such as protons that are secreted by microbes such as acid producing bacteria (APB). The biofilms in this case supply the locally high concentrations of oxidants that are corrosive without biocatalysis. This work describes a mechanistic model that is based on the biocatalytic cathodic sulfate reduction (BCSR) theory. The model utilizes charge transfer and mass transfer concepts to describe the SRB biocorrosion process. The model also includes a mechanism to describe APB attack based on the local acidic pH at a pit bottom. A pitting prediction software package has been created based on the mechanisms. It predicts long-term pitting rates and worst-case scenarios after calibration using SRB short-term pit depth data. Various parameters can be investigated through computer simulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Evaluation of the spoilage potential of bacteria isolated from chilled chicken in vitro and in situ.

    Science.gov (United States)

    Wang, Guang-Yu; Wang, Hu-Hu; Han, Yi-Wei; Xing, Tong; Ye, Ke-Ping; Xu, Xing-Lian; Zhou, Guang-Hong

    2017-05-01

    Microorganisms play an important role in the spoilage of chilled chicken. In this study, a total of 53 isolates, belonging to 7 species of 3 genera, were isolated using a selective medium based on the capacity to spoil chicken juice. Four isolates, namely Aeromonas salmonicida 35, Pseudomonas fluorescens H5, Pseudomonas fragi H8 and Serratia liquefaciens 17, were further characterized to assess their proteolytic activities in vitro using meat protein extracts and to evaluate their spoilage potential in situ. The in vitro studies showed that A. salmonicida 35 displayed the strongest proteolytic activity against both sarcoplasmic and myofibrillar proteins. However, the major spoilage isolate in situ was P. fragi H8, which exhibited a fast growth rate, slime formation and increased pH and total volatile basic nitrogen (TVBN) on chicken breast fillets. The relative amounts of volatile organic compounds (VOCs) originating from the microorganisms, including alcohols, aldehydes, ketones and several sulfur compounds, increased during storage. In sum, this study demonstrated the characteristics of 4 potential spoilage bacteria on chilled yellow-feather chicken and provides a simple and convenient method to assess spoilage bacteria during quality management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Symbiotic interaction of endophytic bacteria with arbuscular mycorrhizal fungi and its antagonistic effect on Ganoderma boninense.

    Science.gov (United States)

    Sundram, Shamala; Meon, Sariah; Seman, Idris Abu; Othman, Radziah

    2011-08-01

    Endophytic bacteria (Pseudomonas aeruginosa UPMP3 and Burkholderia cepacia UMPB3), isolated from within roots of oil palm (Elaeis guineensis Jacq.) were tested for their presymbiotic effects on two arbuscular mcorrhizal fungi, Glomus intraradices UT126 and Glomus clarum BR152B). These endophytic bacteria were also tested for antagonistic effects on Ganoderma boninense PER 71, a white wood rot fungal pathogen that causes a serious disease in oil palm. Spore germination and hyphal length of each arbuscular mycorrhizal fungal (AMF) pairing with endophytic bacteria was found to be significantly higher than spores plated in the absence of bacteria. Scanning electron microscopy (SEM) showed that the endophytic bacteria were scattered, resting or embedded on the surface hyaline layer or on the degraded walls of AMF spores, possibly feeding on the outer hyaline spore wall. The antagonistic effect of the endophytic bacteria was expressed as severe morphological abnormalities in the hyphal structures of G. boninense PER 71. The effects of the endophytic bacteria on G. boninense PER 71 hyphal structures were observed clearly under SEM. Severe inter-twisting, distortion, lysis and shriveling of the hyphal structures were observed. This study found that the effect of endophytic bacteria on G. intraradices UT126 and G. clarum BR152B resembled that of a mycorrhiza helper bacteria (MHB) association because the association significantly promoted AMF spore germination and hyphal length. However, the endophytic bacteria were extremely damaging to G. boninense PER 71.

  4. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  5. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices.

  6. Formulation of an organic carbon trajectory over a 10-year period on a restored spoil island in south-central Florida

    Science.gov (United States)

    Schafer, T.; Ellis, R.; Osborne, T.; Hicks Pries, C.

    2015-12-01

    Long-term monitoring of restoration projects aims to determine long-term sustainability and stability of restored systems. In coastal wetlands, one indicator of restoration of ecosystem function can be seen with organic matter (specifically carbon) accretion. SL-15, a spoil island in Fort Pierce, Fl was restored in 2005, and has been monitored for return to natural condition over the last 10 years.. To assess sediment carbon accretion, sediment cores were collected in a set of eight plots, located on the SL-15 mangrove island and the surrounding seagrass recruitment area. These were analyzed for organic carbon, microbial biomass carbon, extractable carbon, and total nitrogen. The biogeochemical data collected in the previous year was compared to data collected in 2005-2007. Vegetation surveys were also completed to show the build-up of organic material in accordance with vegetation shift over the 9-year period. From this information, a trajectory has been formulated on organic carbon accretion and vegetation shift from the time of orginal restoration activities. By comparison to control sites nearby, realistic estimates of time required to reach natural levels of carbon and vegetation community structure can be calculated..

  7. The Identification of Novel Diagnostic Marker Genes for the Detection of Beer Spoiling Pediococcus damnosus Strains Using the BlAst Diagnostic Gene findEr.

    Directory of Open Access Journals (Sweden)

    Jürgen Behr

    Full Text Available As the number of bacterial genomes increases dramatically, the demand for easy to use tools with transparent functionality and comprehensible output for applied comparative genomics grows as well. We present BlAst Diagnostic Gene findEr (BADGE, a tool for the rapid prediction of diagnostic marker genes (DMGs for the differentiation of bacterial groups (e.g. pathogenic / nonpathogenic. DMG identification settings can be modified easily and installing and running BADGE does not require specific bioinformatics skills. During the BADGE run the user is informed step by step about the DMG finding process, thus making it easy to evaluate the impact of chosen settings and options. On the basis of an example with relevance for beer brewing, being one of the oldest biotechnological processes known, we show a straightforward procedure, from phenotyping, genome sequencing, assembly and annotation, up to a discriminant marker gene PCR assay, making comparative genomics a means to an end. The value and the functionality of BADGE were thoroughly examined, resulting in the successful identification and validation of an outstanding novel DMG (fabZ for the discrimination of harmless and harmful contaminations of Pediococcus damnosus, which can be applied for spoilage risk determination in breweries. Concomitantly, we present and compare five complete P. damnosus genomes sequenced in this study, finding that the ability to produce the unwanted, spoilage associated off-flavor diacetyl is a plasmid encoded trait in this important beer spoiling species.

  8. Cultivation of high-biomass crops on coal mine spoil banks: Can microbial inoculation compensate for high doses of organic matter?

    Energy Technology Data Exchange (ETDEWEB)

    Gryndler, M.; Sudova, R.; Puschel, D.; Rydlova, J.; Janouskova, M.; Vosatka, M. [Academy of Science Czech Republic, Pruhonice (Czech Republic)

    2008-09-15

    Two greenhouse experiments were focused on the application of arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) in planting of high-biomass crops on reclaimed spoil banks. In the first experiment, we tested the effects of different organic amendments on growth of alfalfa and on the introduced microorganisms. While growth of plants was supported in substrate with compost amendment, mycorrhizal colonization was suppressed. Lignocellulose papermill waste had no negative effects on AMF, but did not positively affect growth of plants. The mixture of these two amendments was found to be optimal in both respects, plant growth and mycorrhizal development. Decreasing doses of this mixture amendment were used in the second experiment, where the effects of microbial inoculation (assumed to compensate for reduced doses of organic matter) on growth of two high-biomass crops, hemp and reed canarygrass, were studied. Plant growth response to microbial inoculation was either positive or negative, depending on the dose of the applied amendment and plant species.

  9. Effect of lime, N, P, and K amendments to surface-mined coal spoils on yield and chemical composition of common Bermuda grass

    Energy Technology Data Exchange (ETDEWEB)

    Ebelhar, M W; Barnhisel, R I; Akin, G W; Powell, J L

    1982-12-01

    Common Bermuda grass (Cynodon dactylon, L. Pers.) was used as an alternative to cool-season grasses such as tall fescue (Festuca arundinacea Schreb.) on acid sandstone surface-mine spoils in western Kentucky. Lime, N, P, and K fertilizer amendments were evaluated as to their effects in promoting Bermuda grass growth and development. The applied lime was effective in raising the pH from 3.4 to 4.6, 5.7, and 6.3 for the 18, 36 and 72 metric ton/ha treatments, respectively, over a 17-month period. Nitrogen was found to affect Bermuda grass production significantly and severe deficiency symptoms were observed where N was not applied. Dry matter yields increased significantly with each additional increment of N applied. Although the application of P and K increased the concentration of these ions in the plant tissues, the main influence of P and K was to increase the plants' resistance to winter killing; little effect on total dry matter production was observed. 19 references.

  10. The Identification of Novel Diagnostic Marker Genes for the Detection of Beer Spoiling Pediococcus damnosus Strains Using the BlAst Diagnostic Gene findEr.

    Science.gov (United States)

    Behr, Jürgen; Geissler, Andreas J; Schmid, Jonas; Zehe, Anja; Vogel, Rudi F

    2016-01-01

    As the number of bacterial genomes increases dramatically, the demand for easy to use tools with transparent functionality and comprehensible output for applied comparative genomics grows as well. We present BlAst Diagnostic Gene findEr (BADGE), a tool for the rapid prediction of diagnostic marker genes (DMGs) for the differentiation of bacterial groups (e.g. pathogenic / nonpathogenic). DMG identification settings can be modified easily and installing and running BADGE does not require specific bioinformatics skills. During the BADGE run the user is informed step by step about the DMG finding process, thus making it easy to evaluate the impact of chosen settings and options. On the basis of an example with relevance for beer brewing, being one of the oldest biotechnological processes known, we show a straightforward procedure, from phenotyping, genome sequencing, assembly and annotation, up to a discriminant marker gene PCR assay, making comparative genomics a means to an end. The value and the functionality of BADGE were thoroughly examined, resulting in the successful identification and validation of an outstanding novel DMG (fabZ) for the discrimination of harmless and harmful contaminations of Pediococcus damnosus, which can be applied for spoilage risk determination in breweries. Concomitantly, we present and compare five complete P. damnosus genomes sequenced in this study, finding that the ability to produce the unwanted, spoilage associated off-flavor diacetyl is a plasmid encoded trait in this important beer spoiling species.

  11. Synthesis of Metal Nanoparticles by Bacteria

    Directory of Open Access Journals (Sweden)

    Fikriye Alev Akçay

    2018-04-01

    Full Text Available Metal particles reduced to nano size by nanotechnological methods are confronted in many different fields such as biomedical and physicochemical, pharmaceutical, electric-electronic, automotive and food industries. Nanoparticles can be produced using chemical, physical and biological methods, of which chemical processes are in common use. However, physical and chemical methods are not environmentally friendly and economical because they require the use of high temperature, high pressure and toxic chemicals. For this reason, interest in the production of metal nanoparticles by biological methods, also called green technology, an environmentally friendly and sustainable approach, has increased in recent years. With some plant extracts and intracellular and extracellular secretions of microorganisms, some reduction reactions take place and metal nanoparticles are produced. Bacteria have been actively involved in nanotechnology in recent years due to their diversity in nature, their ease of isolation, and ease of nanoparticle synthesis. In this article, production and application of metal nanoparticles by using bacterial methods have been reviewed.

  12. Corrosion of candidate container materials by Yucca Mountain bacteria

    International Nuclear Information System (INIS)

    Horn, J; Jones, D; Lian, T; Martin, S; Rivera, A

    1999-01-01

    Several candidate container materials have been studied in modified Yucca Mountain (YM) ground water in the presence or absence of YM bacteria. YM bacteria increased corrosion rates by 5-6 fold in UNS G10200 carbon steel, and nearly 100-fold in UNS NO4400 Ni-Cu alloy. YM bacteria caused microbiologically influenced corrosion (MIC) through de-alloying or Ni-depletion of Ni-Cu alloy as evidenced by scanning electronic microscopy (SEM) and inductively coupled plasma spectroscopy (ICP) analysis. MIC rates of more corrosion-resistant alloys such as UNS NO6022 Ni-Cr- MO-W alloy, UN's NO6625 Ni-Cr-Mo alloy, and UNS S30400 stainless steel were measured below 0.05 umyr, however YM bacteria affected depletion of Cr and Fe relative to Ni in these materials. The chemical change on the metal surface caused by depletion was characterized in anodic polarization behavior. The anodic polarization behavior of depleted Ni-based alloys was similar to that of pure Ni. Key words: MIC, container materials, YM bacteria, de-alloying, Ni-depletion, Cr-depletion, polarization resistance, anodic polarization,

  13. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    Directory of Open Access Journals (Sweden)

    José Luis Parada

    2007-05-01

    Full Text Available Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS, useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therapeutic antibiotics. In this context, bacteriocins are indicated to prevent the growth of undesirable bacteria in a food-grade and more natural way, which is convenient for health and accepted by the community. According to their properties, structure, molecular weight (MW, and antimicrobial spectrum, bacteriocins are classified in three different groups: lantibiotics and non-lantibiotics of low MW, and those of higher MW. Several strategies for isolation and purification of bacteriocins from complex cultivation broths to final products were described. Biotechnological procedures including salting-out, solvent extraction, ultrafiltration, adsorption-desortion, ion-exchange, and size exclusion chromatography are among the most usual methods. Peptide structure-function studies of bacteriocins and bacterial genetic advances will help to understand the molecular basis of their specificity and mode of action. Nisin is a good example of commercial success, and a good perspective is open to continue the study and development of new bacteriocins and their biotechnological applications. These substances in appropriate concentrations may be used in veterinary medicine and as animal growth promoter instead usual antibiotics, as well as an additional hurdle factor for increasing the shelf life of minimal processed foods.

  14. The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter

    International Nuclear Information System (INIS)

    Mantel, J.; Freidin, M.; Perry, H.

    1983-01-01

    The purpose of the study was to investigate the response of the bioluminescent Photobacterium phosphoreum to radiation, and the possible use of the bacteria as a biological radiation dosemeter, i.e. a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. Samples were irradiated by a 12 MeV electron beam at a dose rate of 3.0 Gy min -1 , by 60 Co gamma rays at 2.85 Gy min -1 , and by 100 kVsub(p) x-rays at a dose rate of 2.13 Gy min -1 . To study dose-rate dependence, the survival fraction was obtained for a 12 MeV electron beam at 0.50 and 12 Gy min -1 for 20.0 Gy. The survival fraction proved to be independent of dose rate in this range. The results presented in this work indicate that by using bioluminescent bacteria, RBE measurements can be markedly simplified and the results interpreted unequivocally. (U.K.)

  15. ENDOSPORES OF THERMOPHILIC FERMENTATIVE BACTERIA

    DEFF Research Database (Denmark)

    Volpi, Marta

    2016-01-01

    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  16. Alternative sources of Legionella bacteria

    NARCIS (Netherlands)

    van Heijnsbergen, H.H.L.

    2017-01-01

    Legionella bacteria can cause Legionnaires’ disease (LD) in humans. Symptoms of LD can range from mild disease to severe pneumonia with sometimes fatal outcome. In the Netherlands, the most important infective agent is Legionella pneumophila. L. pneumophila infection is associated with aquatic

  17. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...

  18. Automated radiometric detection of bacteria

    International Nuclear Information System (INIS)

    Waters, J.R.

    1974-01-01

    A new radiometric method called BACTEC, used for the detection of bacteria in cultures or in supposedly sterile samples, was discussed from the standpoint of methodology, both automated and semi-automated. Some of the results obtained so far were reported and some future applications and development possibilities were described. In this new method, the test sample is incubated in a sealed vial with a liquid culture medium containing a 14 C-labeled substrate. If bacteria are present, they break down the substrate, producing 14 CO 2 which is periodically extracted from the vial as a gas and is tested for radioactivity. If this gaseous radioactivity exceeds a threshold level, it is evidence of bacterial presence and growth in the test vial. The first application was for the detection of bacteria in the blood cultures of hospital patients. Data were presented showing typical results. Also discussed were future applications, such as rapid screening for bacteria in urine industrial sterility testing and the disposal of used 14 C substrates. (Mukohata, S.)

  19. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  20. Deodorant bacteria; Des bacteries desodorisantes

    Energy Technology Data Exchange (ETDEWEB)

    Fanlo, J.L. [Ecole Nationale Superieure des Mines, 30 - Ales (France)

    1998-02-01

    Purifying bacteria: if this concept is not new, its application to gases cleansing has only been developed recently. This method allows to eliminate the volatile organic compounds and the gaseous effluents odors which come from industrial sites. Three bioreactors types exist at the present time. Their principles are explained. (O.M.) 6 refs.

  1. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  2. Biochemistry, physiology and biotechnology of sulfate-reducing bacteria.

    Science.gov (United States)

    Barton, Larry L; Fauque, Guy D

    2009-01-01

    Chemolithotrophic bacteria that use sulfate as terminal electron acceptor (sulfate-reducing bacteria) constitute a unique physiological group of microorganisms that couple anaerobic electron transport to ATP synthesis. These bacteria (220 species of 60 genera) can use a large variety of compounds as electron donors and to mediate electron flow they have a vast array of proteins with redox active metal groups. This chapter deals with the distribution in the environment and the major physiological and metabolic characteristics of sulfate-reducing bacteria (SRB). This chapter presents our current knowledge of soluble electron transfer proteins and transmembrane redox complexes that are playing an essential role in the dissimilatory sulfate reduction pathway of SRB of the genus Desulfovibrio. Environmentally important activities displayed by SRB are a consequence of the unique electron transport components or the production of high levels of H(2)S. The capability of SRB to utilize hydrocarbons in pure cultures and consortia has resulted in using these bacteria for bioremediation of BTEX (benzene, toluene, ethylbenzene and xylene) compounds in contaminated soils. Specific strains of SRB are capable of reducing 3-chlorobenzoate, chloroethenes, or nitroaromatic compounds and this has resulted in proposals to use SRB for bioremediation of environments containing trinitrotoluene and polychloroethenes. Since SRB have displayed dissimilatory reduction of U(VI) and Cr(VI), several biotechnology procedures have been proposed for using SRB in bioremediation of toxic metals. Additional non-specific metal reductase activity has resulted in using SRB for recovery of precious metals (e.g. platinum, palladium and gold) from waste streams. Since bacterially produced sulfide contributes to the souring of oil fields, corrosion of concrete, and discoloration of stonework is a serious problem, there is considerable interest in controlling the sulfidogenic activity of the SRB. The

  3. Epithermal neutron activation analysis of CR(VI)-reducer basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Tsibakhashvili, N.Ya.; Kalabegishvili, T.L.; Murusidze, I.G.; Mosulishvili, L.M.; Frontas'eva, M.V.; Kirkesali, E.I.; Aksenova, N.G.; Holman, H.Y.

    2005-01-01

    Epithermal neutron activation analysis (ENAA) has been applied to studying elemental composition of Cr(VI)-reducer bacteria isolated from polluted basalts from the Republic of Georgia. Cr(VI)-reducing ability of the bacteria was examined by electron spin resonance (ESR) demonstrating that the bacteria differ in the rates of Cr(VI) reduction. A well-pronounced correlation between the ability of the bacteria to accumulate Cr(VI) and their ability to reduce Cr(V) to Cr(III) observed in our experiments is discussed. Elemental analysis of these bacteria also revealed that basalt-inhabiting bacteria are distinguished by relative contents of essential elements such as K, Na, Mg, Fe, Mn, Zn, and Co. A high rate of Cr(III) formation correlates with a high concentration of Co in the bacterium. ENAA detected some similarity in the elemental composition of the bacteria. The relatively high contents of Fe detected in the bacteria (140-340 μg/g of dry weight) indicate bacterial adaptation to the environmental conditions typical of the basalts. The concentrations of at least 12-19 different elements ranging from major- to ultratrace ones were determined in each type of bacteria simultaneously. The range of concentrations spans over 8 orders of magnitude

  4. Size-dependent antibacterial activities of silver nanoparticles against oral anaerobic pathogenic bacteria.

    Science.gov (United States)

    Lu, Zhong; Rong, Kaifeng; Li, Ju; Yang, Hao; Chen, Rong

    2013-06-01

    Dental caries and periodontal disease are widespread diseases for which microorganism infections have been identified as the main etiology. Silver nanoparticles (Ag Nps) were considered as potential control oral bacteria infection agent due to its excellent antimicrobial activity and non acute toxic effects on human cells. In this work, stable Ag Nps with different sizes (~5, 15 and 55 nm mean values) were synthesized by using a simple reduction method or hydrothermal method. The Nps were characterized by powder X-ray diffraction, transmission electron microscopy and UV-vis absorption spectroscopy. The antibacterial activities were evaluated by colony counting assay and growth inhibition curve method, and corresponding minimum inhibitory concentration (MIC) against five anaerobic oral pathogenic bacteria and aerobic bacteria E. coli were determined. The results showed that Ag Nps had apparent antibacterial effects against the anaerobic oral pathogenic bacteria and aerobic bacteria. The MIC values of 5-nm Ag against anaerobic oral pathogenic bacteria A. actinomycetemcomitans, F. nuceatum, S. mitis, S. mutans and S. sanguis were 25, 25, 25, 50 and 50 μg/mL, respectively. The aerobic bacteria were more susceptible to Ag NPs than the anaerobic oral pathogenic bacteria. In the mean time, Ag NPs displayed an obvious size-dependent antibacterial activity against the anaerobic bacteria. The 5-nm Ag presents the highest antibacterial activity. The results of this work indicated a potential application of Ag Nps in the inhibition of oral microorganism infections.

  5. Metabolic interactions between methanogenic consortia and anaerobic respiring bacteria

    DEFF Research Database (Denmark)

    Stams, A.J.; Oude Elferink, S.J.; Westermann, Peter

    2003-01-01

    Most types of anaerobic respiration are able to outcompete methanogenic consortia for common substrates if the respective electron acceptors are present in sufficient amounts. Furthermore, several products or intermediate compounds formed by anaerobic respiring bacteria are toxic to methanogenic...... consortia. Despite the potentially adverse effects, only few inorganic electron acceptors potentially utilizable for anaerobic respiration have been investigated with respect to negative interactions in anaerobic digesters. In this chapter we review competitive and inhibitory interactions between anaerobic...... respiring populations and methanogenic consortia in bioreactors. Due to the few studies in anaerobic digesters, many of our discussions are based upon studies of defined cultures or natural ecosystems...

  6. Transformation of monothioarsenate by haloalkaliphilic, anoxygenic photosynthetic purple sulfur bacteria.

    Science.gov (United States)

    Edwardson, Christian F; Planer-Friedrich, Britta; Hollibaugh, James T

    2014-12-01

    Thioarsenates are the dominant arsenic species in arsenic-rich, alkaline, and sulfidic waters, but bacterial interactions with these compounds have only recently been examined. Previous studies have shown that microorganisms play a role in the transformation of monothioarsenate to arsenate, including use of monothioarsenate as a chemolithotrophic electron donor coupled with oxygen as an electron acceptor. We obtained enrichment cultures from two saline, alkaline lakes (Mono Lake, CA and Big Soda Lake, NV) that are able to use monothioarsenate as the sole electron donor for anoxygenic photosynthesis. These anoxic cultures were able to convert a 1 mM mixture of thioarsenates completely to arsenate in c. 13 days and 4 mM monothioarsenate to arsenate in c. 17 days. This conversion was light dependent; thus, monothioarsenate can be used as the sole electron donor for anoxygenic photosynthesis. Both of the Mono Lake and Big Soda Lake enrichment cultures were dominated by an organism closely related to Ectothiorhodospira species. We tested additional strains of purple sulfur bacteria and found widespread ability to use monothioarsenate as an electron donor. The ability of bacteria to transform thioarsenates directly via anoxygenic photosynthesis adds a new perspective to the well-studied arsenic and sulfur cycles. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  7. Comparison of fast spin echo, fast multiplanner spoiled gradient recalled and conventional T1 and T2 weighted imaging for experimentally induced hepatic tumors in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myeong Jin; Lee, Jong Tae; Suh, Jin Suk; Choi, Pil Sik; Lee, Yeon Hee; Yoo, Hyung Sik; Kim, Ki Whang [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1994-10-15

    To compare the ability of tumor detection and the lesion conspicuity between T1- and T2-weighted fast scanning sequence and T1- and T2-weighted conventional spin echo techniques in MR imaging of hepatic tumors. Hepatic tumors were induced on 13 male Sprague-Dawley rats by feeding 3'-methyl-dimethylethyl aminoazobenzene mixed with Miller's III formula for 12 weeks. MR images were obtained with 1.5 T magnet with dual TMJ coil(Sigma, GE Medical systems, Milwaukee, USA). Animals were anesthetized with 150 mg/kg of ketamine hydrochloride. T2 weighted fast spin echo(FSE), conventional spin echo(CSE) T2- and T1WI, fast multiplanner spoiled gradient recalled(FMPSPGR) imaging were obtained. Number of detected tumors and contrast-to-noise ratio of the tumors were compared for each sequence. Overall 110 tumors were developed. 75% of the tumors were detected on FSE. 65% on FMPSPGR, 41% on conventional T2WI, and 41% on T1WI images. For tumors more than 5 mm in diameter, sensitivity was 88% on FMPSPGR, 65% on conventional T2WI, and 81% on T1WI images respectively. CNR of the tumor was 28.94 {+-} 21.6 on FSE, 13.57 {+-} 8.64 on FMPSPGR, 12.62 {+-} 10.65 on CSE T2WI, and 9.47 {+-} 8.05 on CSE T1WI images, which was significantly high on FSE(p<0.05). Fast spin echo T2WI shows highest sensitivity and tumor-to-liver contrast. FMPSPGR imaging is also favorably comparable with conventional T1WI. Therefore, these two pulse sequences can be useful in clinical condition for hepatic MR imaging.

  8. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  9. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  10. Oligotrophic bacteria isolated from clinical materials.

    OpenAIRE

    Tada, Y; Ihmori, M; Yamaguchi, J

    1995-01-01

    Oligotrophic bacteria (oligotrophs) are microorganisms that grow in extremely nutritionally deficient conditions in which the concentrations of organic substances are low. Many oligotrophic bacteria were isolated from clinical materials including urine, sputum, swabbings of the throat, vaginal discharges, and others. Seventy-seven strains of oligotrophic bacteria from 871 samples of clinical material were isolated. A relatively higher frequency of isolation of oligotrophic bacteria was shown ...

  11. Cell wall as a target for bacteria inactivation by pulsed electric fields

    Science.gov (United States)

    Pillet, Flavien; Formosa-Dague, Cécile; Baaziz, Houda; Dague, Etienne; Rols, Marie-Pierre

    2016-01-01

    The integrity and morphology of bacteria is sustained by the cell wall, the target of the main microbial inactivation processes. One promising approach to inactivation is based on the use of pulsed electric fields (PEF). The current dogma is that irreversible cell membrane electro-permeabilisation causes the death of the bacteria. However, the actual effect on the cell-wall architecture has been poorly explored. Here we combine atomic force microscopy and electron microscopy to study the cell-wall organization of living Bacillus pumilus bacteria at the nanoscale. For vegetative bacteria, exposure to PEF led to structural disorganization correlated with morphological and mechanical alterations of the cell wall. For spores, PEF exposure led to the partial destruction of coat protein nanostructures, associated with internal alterations of cortex and core. Our findings reveal for the first time that the cell wall and coat architecture are directly involved in the electro-eradication of bacteria. PMID:26830154

  12. Geobiology of Marine Magnetotactic Bacteria

    Science.gov (United States)

    2006-06-01

    prokaryotic cells of diverse phylogeny when grown in media containing 45 1mM iron, suggesting some kind of detoxification function . The inclusions were...salt marsh productivity. FISH also showed that aggregates consist of genetically identical cells. QPCR data indicated that populations are finely...my advisor Katrina Edwards for taking a chance on someone who initially knew nothing about magnetotactic bacteria, microbial ecology , or microbiology

  13. Teknik Pengawetan Fillet Ikan Nila Merah dengan Senyawa Anti Bakteri asal Lactobacillus Acidophilus dan Bifido Bacteria Biffidum

    Directory of Open Access Journals (Sweden)

    Dede Saputra

    2014-12-01

    Full Text Available Red tilapia is a good commodity to be developed because it has a high nutritional value composition, with a protein content 17.8%, fat 2.8%, and others composition. The fillet of red tilapia fish is easy to spoil, because of S. aureus, Salmonella sp., and other microbes. Many methods are used to save and preserve the quality of fillet, such fillet preparation through good sanitation practices, cooling process, but the effort were not optimal. The objectives of this study were to 1 evaluate the potency of antibacterial produced by Lactobacillus acidophilus and Bifidobacteria biffidum to inhibit the growth of spoilage bacteria that contaminated the red tilapia fillet; 2 evaluate the effect of antibacterial compounds produced by Lactobacillus acidophilus and Bifidobacteria biffidum of inhibiting the setback fillet quality, 3 determine the shelf life of red tilapia fillet at room temperature. Antibacterial activity test is done by using the well diffusion method; the rate of deterioration of quality of fish tests done by observing the organoleptic parameters, pH measurement test, total volatile base method. Total number of bacteria were performed by Standard Plate Count (SPC test. The LAB’s are able to inhibit the growth of spoilage bacteria Pseudomonas aeruginosa about 8.67-9.00 mm and Listeria monocytogenes about 8.33-9.00 mm through the well diffusion method. pH values about 5.71-5.74, TVB values about 1,26-21.43 with SPC test about 1.39-4.83 CFU/mL. The antibacterial compounds could inhibit  the rate of deterioration of quality red tilapia fillets until 14 hours.

  14. Effect of chromate action on morphology of basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Lin Zhang; Zhu Ying; Kalabegishvili, Tamaz L.; Tsibakhashvili, Nelly Y.; Holman, Hoi-Ying

    2006-01-01

    Basalt-inhabiting bacteria isolated from polluted basalts have been demonstrated to be able to tolerate moderate to high concentrations of chromium oxyanions such as chromate. Previous results have shown that macromolecules outside the cell wall of bacteria may play an important role in this survival ability. In this paper, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were applied to study the chromate-induced morphological changes in chromate-resistant basalt-inhabiting Arthrobacter K-2 and K-4, which were isolated from the Republic of Georgia. The surfaces of both strains changed in the presence of chromate. TEM thin sections show that chromate stimulates the appearance of bacteria capsular polysaccharide outside the cell wall, although the chromate concentration does not have a strong effect on the capsular thickness. These results, in conjunction with those reported earlier, provide direct evidence to show that capsular polysaccharides of the bacteria play very important role for the reduction and localization of chromate

  15. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

  16. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  17. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in

  18. Ecology of mycophagous collimonas bacteria in soil

    NARCIS (Netherlands)

    Höppener-Ogawa, Sachie

    2008-01-01

    Bacteria belonging to the genus Collimonas consist of soil bacteria that can grow at expense of living fungal hyphae i.e. they are mycophagous. This PhD studies deals with the ecology of mycophagous bacteria in soil using collimonads as model organisms. Collimonads were found to be widely

  19. Low field orientation magnetic separation methods for magnetotactic bacteria

    International Nuclear Information System (INIS)

    Moeschler, F.D.

    1999-01-01

    Microbial biomineralisation of iron often results in a biomass that is magnetic and can be separated from water systems by the application of a magnetic field. Magnetotactic bacteria form magnetic membrane bound crystals within their structure, generally of magnetite. In nature, this enables magnetotactic bacteria to orientate themselves with respect to the local geomagnetic field. The bacteria then migrate with flagellar driven motion towards their preferred environment. This property has been harnessed to produce a process in which metal loaded magnetotactic bacteria can be recovered from a waste stream. This process is known as orientation magnetic separation. Several methods exist which permit the unique magnetic properties of individual magnetotactic bacteria to be studied, such as U-turn analysis, transmission electron microscopy and single wire cell studies. In this work an extension of U-turn analysis was developed. The bacteria were rendered non-motile by the addition of specific metal ions and the resulting 'flip time' which occurs during a field reversal enabled the magnetic moment of individual bacteria to be determined. This method proved to be much faster and more accurate than previous methods. For a successful process to be developed, large scale culturing of magnetotactic bacteria is required Experiments showed that culture vessel geometry was an important factor for high-density growth. Despite intensive studies reproducible culturing at volumes exceeding one litre was not achieved. This work showed that numerous metal ions rendered magnetotactic bacteria non-motile at concentrations below 10 ppm. Sequential adaptation raised typical levels to in excess of 100 ppm for a number of ions. such as zinc and tin. However, specific ions. such as copper or nickel, remained motility inhibiting at lower concentrations. To achieve separation using orientation magnetic separation, motile, field susceptible MTB are required. Despite successful adaptation, the

  20. Food spoilage - interactions between food spoilage bacteria

    DEFF Research Database (Denmark)

    Gram, Lone; Flodgaard, Lars; Rasch, Maria

    2002-01-01

    Food spoilage is a complex process and excessive amounts of foods are lost due to microbial spoilage even with modem day preservation techniques. Despite the heterogeneity in raw materials and processing conditions, the microflora that develops during storage and in spoiling foods can be predicted...... based on knowledge of the origin of the food, the substrate base and a few central preservation parameters such as temperature, atmosphere, a(w) and pH. Based on such knowledge, more detailed sensory, chemical and microbiological analysis can be carried out on the individual products to determine...... the actual specific spoilage organism. Whilst the chemical and physical parameters are the main determining factors for selection of spoilage microorganisms, a level of refinement may be found in some products in which the interactive behavior of microorganisms may contribute to their growth and/or spoilage...

  1. Chemical and isotopic tracing of underground water in relation with leaching of mine spoils, Nord-Pas-de-Calais Coal Basin (France); Tracage chimique et isotopique des eaux souterraines en relation avec les eaux de lixiviation de terrils, bassin minier du Nord-Pas-de-Calais (France)

    Energy Technology Data Exchange (ETDEWEB)

    Denimal, S.; Tribovillard, N.; Meilliez, F. [Lille-1 Univ., Lab. de Sedimentologie et Geodynamique, UMR 8577, 59 - Villeneuve-d' Ascq (France); Barbecot, F.; Dever, L. [Paris-11 Univ., Lab. d' Hydrologie et de Geochimie Isotopique, UMR 8616, 91 - Orsay (France)

    2001-07-01

    Coal mining activity in the Nord-Pas-de-Calais region (Northern France) has generated many mine spoils. The oxidation of the pyrite content of such coal shales and their leaching can be a source of sulfate pollution for the underlying chalk aquifer, i.e. the main drinking water resource of the region. Two sites of study have been retained: one in the free water table zone and the other in the confined water table zone. Samples from both mine spoils have been analyzed with respect to their carbon and sulfur content and a superficial leaching of these elements has been evidenced. Water has been sampled in piezometers and boreholes close to the mine spoils and also along natural flux lines. The use of sulfur isotopes as markers of the different sulfate sources has confirmed the spoils source but has permitted to identify another source in the second site which is the Tertiary gypsum-bearing Ostricourt sands. This study has shown also that in the confined water table zone, part of the exported sulfates is reduced. This bacterial reduction of sulfates is due to a joint leaching of both carbon and sulfur in the mine spoils. A self-purification phenomenon occurs when the chalk aquifer is confined beneath the Cenozoic cover. (J.S.)

  2. Experimental investigation of activities and tolerance of denitrifying bacteria under alkaline and reducing condition

    International Nuclear Information System (INIS)

    Mine, Tatsuya; Mihara, Morihiro; Ooi, Takao

    2000-07-01

    In the geological disposal system of TRU wastes, nitrogen generation by denitrifying bacteria could provide significant impact on the assessment of this system, because nitrate contained in process concentrated liquid waste might be electron acceptor for denitrifying bacteria. In this study, the activities and tolerance of denitrifying under disposal condition were investigated. Pseudomonas denitrificans as denitrifying bacteria was used. The results showed that Pseudomonas denitrificans had activity under reducing condition, but under high pH condition (pH>9.5), the activity of Pseudomonas denitrificans was not detected. It is possible that the activity of Pseudomonas denitrificans would be low under disposal condition. (author)

  3. Energetics and Application of Heterotrophy in Acetogenic Bacteria.

    Science.gov (United States)

    Schuchmann, Kai; Müller, Volker

    2016-07-15

    Acetogenic bacteria are a diverse group of strictly anaerobic bacteria that utilize the Wood-Ljungdahl pathway for CO2 fixation and energy conservation. These microorganisms play an important part in the global carbon cycle and are a key component of the anaerobic food web. Their most prominent metabolic feature is autotrophic growth with molecular hydrogen and carbon dioxide as the substrates. However, most members also show an outstanding metabolic flexibility for utilizing a vast variety of different substrates. In contrast to autotrophic growth, which is hardly competitive, metabolic flexibility is seen as a key ability of acetogens to compete in ecosystems and might explain the almost-ubiquitous distribution of acetogenic bacteria in anoxic environments. This review covers the latest findings with respect to the heterotrophic metabolism of acetogenic bacteria, including utilization of carbohydrates, lactate, and different alcohols, especially in the model acetogen Acetobacterium woodii Modularity of metabolism, a key concept of pathway design in synthetic biology, together with electron bifurcation, to overcome energetic barriers, appears to be the basis for the amazing substrate spectrum. At the same time, acetogens depend on only a relatively small number of enzymes to expand the substrate spectrum. We will discuss the energetic advantages of coupling CO2 reduction to fermentations that exploit otherwise-inaccessible substrates and the ecological advantages, as well as the biotechnological applications of the heterotrophic metabolism of acetogens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  4. Selecting colliery spoil from Puentes mine for the purpose of tip restoration. Influencia de la seleccion de los esteriles de la Mina Puentes en la restauracion de la escombrera

    Energy Technology Data Exchange (ETDEWEB)

    Gil Bueno, A; Macias Vazquez, F; Monterroso Martinez, C; Val Caballero, C

    1990-12-01

    Presents the results of a study conducted into the physical and chemical properties of material from coal faces at Puentes Mine in the La Coruna region of Spain. The main objective was to study waste material with a view to selecting the type most suitable to act as the covering layer for colliery spoil tips. The selection method employed has created tips with a top layer suitable for planting. The article also describes the methods used in the restoration work. 6 refs., 3 tabs., 4 figs.

  5. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    OpenAIRE

    Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging...

  6. Electronic technology

    International Nuclear Information System (INIS)

    Kim, Jin Su

    2010-07-01

    This book is composed of five chapters, which introduces electronic technology about understanding of electronic, electronic component, radio, electronic application, communication technology, semiconductor on its basic, free electron and hole, intrinsic semiconductor and semiconductor element, Diode such as PN junction diode, characteristic of junction diode, rectifier circuit and smoothing circuit, transistor on structure of transistor, characteristic of transistor and common emitter circuit, electronic application about electronic equipment, communication technology and education, robot technology and high electronic technology.

  7. Epithermal Neutron Activation Analysis (ENAA) of Cr(VI)-reducer Basalt-inhabiting Bacteria

    CERN Document Server

    Tsibakhashvili, N Ya; Kirkesali, E I; Aksenova, N G; Kalabegishvili, T L; Murusidze, I G; Mosulishvili, L M; Holman, H Y N

    2005-01-01

    Epithermal neutron activation analysis (ENAA) has been applied to studying elemental composition of Cr(VI)-reducer bacteria isolated from polluted basalts from the Republic of Georgia. Cr(VI)-reducing ability of the bacteria was examined by electron spin resonance (ESR) demonstrating that the bacteria differ in the rates of Cr(VI) reduction. A well-pronounced correlation between the ability of the bacteria to accumulate Cr(V) and their ability to reduce Cr(V) to Cr(III) observed in our experiments is discussed. Elemental analysis of these bacteria also revealed that basalt-inhabiting bacteria are distinguished by relative contents of essential elements such as K, Na, Mg, Fe, Mn, Zn, and Co. A high rate of Cr(III) formation correlates with a high concentration of Co in the bacterium. ENAA detected some similarity in the elemental composition of the bacteria. The relatively high contents of Fe detected in the bacteria (140-340 $\\mu $g/g of dry weight) indicate bacterial adaptation to the environmental condition...

  8. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  9. Endocarditis caused by anaerobic bacteria.

    Science.gov (United States)

    Kestler, M; Muñoz, P; Marín, M; Goenaga, M A; Idígoras Viedma, P; de Alarcón, A; Lepe, J A; Sousa Regueiro, D; Bravo-Ferrer, J M; Pajarón, M; Costas, C; García-López, M V; Hidalgo-Tenorio, C; Moreno, M; Bouza, E

    2017-10-01

    Infective endocarditis (IE) caused by anaerobic bacteria is a rare and poorly characterized disease. Most data reported in the literature are from case reports [1-3]. Therefore, we assessed the situation of anaerobic IE (AIE) in Spain using the database of the Spanish Collaboration on Endocarditis (GAMES). We performed a prospective study from 2008 to 2016 in 26 Spanish centers. We included 2491 consecutive cases of definite IE (Duke criteria). Anaerobic bacteria caused 22 cases (0.9%) of definite IE. Median age was 66 years (IQR, 56-73), and 19 (86.4%) patients were men. Most patients (14 [63.6%]) had prosthetic valve IE and all episodes were left-sided: aortic valves, 12 (54.5%); and mitral valves, 8 (36.4%). The most common pathogens were Propionibacterium acnes (14 [63.6%]), Lactobacillus spp (3 [13.63%]), and Clostridium spp. (2 [9.0%]), and the infection was mainly odontogenic. Fifteen of the 22 patients (68.2%) underwent cardiac surgery. Mortality was 18.2% during admission and 5.5% after 1 year of follow-up. When patients with AIE were compared with the rest of the cohort, we found that although those with AIE had a similar age and Charlson comorbidity index, they were more likely to have community-acquired IE (86.4% vs. 60.9%, p = 0.01), have undergone cardiac surgery (68.2% vs 48.7% p = 0.06), and have had lower mortality rates during admission (18.2% vs. 27.3%). IE due to anaerobic bacteria is an uncommon disease that affects mainly prosthetic valves and frequently requires surgery. Otherwise, there are no major differences between AIE and IE caused by other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  11. Bacteria and vampirism in cinema.

    Science.gov (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  12. Space-charge effects on bunching of electrons in the CEBAF injector

    International Nuclear Information System (INIS)

    Liu, H.

    1997-01-01

    The main injector for the 4 GeV CEBAF accelerator at Thomas Jefferson national accelerator facility was designed to deliver simultaneously three CW electron beams for nuclear physics research. The maximum design current for a single beam from the injector is 100 μA, or 0.2 pC per microbunch at a repetition rate of 499 MHz. It was found through computer simulation that space charge even at a subpicocoulomb level can spoil the bunching of electrons significantly, and some unexpected phenomena observed experimentally could be explained accordingly. This problem arises because of the low-momentum tilt allowed for bunching to preserve low-momentum spread. In this paper, we analyze in detail the space-charge effects on bunching of electrons with the CEBAF injector as an example. Conditions for effective matching of longitudinal phase space in the presence of space charge are discussed. (orig.)

  13. An analysis of the uncertainty and bias in DCE-MRI measurements using the spoiled gradient-recalled echo pulse sequence

    International Nuclear Information System (INIS)

    Subashi, Ergys; Choudhury, Kingshuk R.; Johnson, G. Allan

    2014-01-01

    Purpose: The pharmacokinetic parameters derived from dynamic contrast-enhanced (DCE) MRI have been used in more than 100 phase I trials and investigator led studies. A comparison of the absolute values of these quantities requires an estimation of their respective probability distribution function (PDF). The statistical variation of the DCE-MRI measurement is analyzed by considering the fundamental sources of error in the MR signal intensity acquired with the spoiled gradient-echo (SPGR) pulse sequence. Methods: The variance in the SPGR signal intensity arises from quadrature detection and excitation flip angle inconsistency. The noise power was measured in 11 phantoms of contrast agent concentration in the range [0–1] mM (in steps of 0.1 mM) and in onein vivo acquisition of a tumor-bearing mouse. The distribution of the flip angle was determined in a uniform 10 mM CuSO 4 phantom using the spin echo double angle method. The PDF of a wide range of T1 values measured with the varying flip angle (VFA) technique was estimated through numerical simulations of the SPGR equation. The resultant uncertainty in contrast agent concentration was incorporated in the most common model of tracer exchange kinetics and the PDF of the derived pharmacokinetic parameters was studied numerically. Results: The VFA method is an unbiased technique for measuringT1 only in the absence of bias in excitation flip angle. The time-dependent concentration of the contrast agent measured in vivo is within the theoretically predicted uncertainty. The uncertainty in measuring K trans with SPGR pulse sequences is of the same order, but always higher than, the uncertainty in measuring the pre-injection longitudinal relaxation time (T1 0 ). The lowest achievable bias/uncertainty in estimating this parameter is approximately 20%–70% higher than the bias/uncertainty in the measurement of the pre-injection T1 map. The fractional volume parameters derived from the extended Tofts model were found to be

  14. A novel antimicrobial peptide against dental-caries-associated bacteria.

    Science.gov (United States)

    Chen, Long; Jia, Lili; Zhang, Qiang; Zhou, Xirui; Liu, Zhuqing; Li, Bingjie; Zhu, Zhentai; Wang, Fenwei; Yu, Changyuan; Zhang, Qian; Chen, Feng; Luo, Shi-Zhong

    2017-10-01

    Dental caries, a highly prevalent oral disease, is primarily caused by pathogenic bacteria infection, and most of them are anaerobic. Herein, we investigated the activity of a designed antimicrobial peptide ZXR-2, and found it showed broad-spectrum activity against a variety of Gram-positive and Gram-negative oral bacteria, particularly the caries-related taxa Streptococcus mutans. Time-course killing assays indicated that ZXR-2 killed most bacterial cells within 5 min at 4 × MIC. The mechanism of ZXR-2 involved disruption of cell membranes, as observed by scanning electron microscopy. Moreover, ZXR-2 inhibited the formation of S. mutans biofilm, but showed limited hemolytic effect. Based on its potent antimicrobial activity, rapid killing, and inhibition of S. mutans biofilm formation, ZXR-2 represents a potential therapeutic for the prevention and treatment of dental caries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Pathogenic mechanisms of intracellular bacteria.

    Science.gov (United States)

    Niller, Hans Helmut; Masa, Roland; Venkei, Annamária; Mészáros, Sándor; Minarovits, Janos

    2017-06-01

    We wished to overview recent data on a subset of epigenetic changes elicited by intracellular bacteria in human cells. Reprogramming the gene expression pattern of various host cells may facilitate bacterial growth, survival, and spread. DNA-(cytosine C5)-methyltransferases of Mycoplasma hyorhinis targeting cytosine-phosphate-guanine (CpG) dinucleotides and a Mycobacterium tuberculosis methyltransferase targeting non-CpG sites methylated the host cell DNA and altered the pattern of gene expression. Gene silencing by CpG methylation and histone deacetylation, mediated by cellular enzymes, also occurred in M. tuberculosis-infected macrophages. M. tuberculosis elicited cell type-specific epigenetic changes: it caused increased DNA methylation in macrophages, but induced demethylation, deposition of euchromatic histone marks and activation of immune-related genes in dendritic cells. A secreted transposase of Acinetobacter baumannii silenced a cellular gene, whereas Mycobacterium leprae altered the epigenotype, phenotype, and fate of infected Schwann cells. The 'keystone pathogen' oral bacterium Porphyromonas gingivalis induced local DNA methylation and increased the level of histone acetylation in host cells. These epigenetic changes at the biofilm-gingiva interface may contribute to the development of periodontitis. Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.

  16. Money and transmission of bacteria.

    Science.gov (United States)

    Gedik, Habip; Voss, Timothy A; Voss, Andreas

    2013-08-28

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria to people who come in contact with the banknotes. The survival rate was highest for the Romanian Leu yielding all three microorganisms used after both three and six hours of drying. Furthermore, the Leu was the only banknote to yield VRE after one day of drying. Other currencies either enabled the survival of Extended-Spectrum Beta-Lactamases (ESBL) and VRE (e.g. Euro), but not of MRSA, or the other way round (e.g. US Dollar). While a variety of factors such as community hygiene levels, people's behaviour, and antimicrobial resistance rates at community level obviously have influence on the transmission of resistant microorganisms, the type of banknote-paper may be an additional variable to consider.

  17. Resistance of Bacteria to Biocides.

    Science.gov (United States)

    Maillard, Jean-Yves

    2018-04-01

    Biocides and formulated biocides are used worldwide for an increasing number of applications despite tightening regulations in Europe and in the United States. One concern is that such intense usage of biocides could lead to increased bacterial resistance to a product and cross-resistance to unrelated antimicrobials including chemotherapeutic antibiotics. Evidence to justify such a concern comes mostly from the use of health care-relevant bacterial isolates, although the number of studies of the resistance characteristics of veterinary isolates to biocides have increased the past few years. One problem remains the definition of "resistance" and how to measure resistance to a biocide. This has yet to be addressed globally, although the measurement of resistance is becoming more pressing, with regulators both in Europe and in the United States demanding that manufacturers provide evidence that their biocidal products will not impact on bacterial resistance. Alongside in vitro evidence of potential antimicrobial cross-resistance following biocide exposure, our understanding of the mechanisms of bacterial resistance and, more recently, our understanding of the effect of biocides to induce a mechanism(s) of resistance in bacteria has improved. This article aims to provide an understanding of the development of antimicrobial resistance in bacteria following a biocide exposure. The sections provide evidence of the occurrence of bacterial resistance and its mechanisms of action and debate how to measure bacterial resistance to biocides. Examples pertinent to the veterinary field are used where appropriate.

  18. Differential scanning calorimetry of bacteria.

    Science.gov (United States)

    Miles, C A; Mackey, B M; Parsons, S E

    1986-04-01

    Thermograms obtained by differential scanning calorimetry of a range of bacteria of different heat resistances were compared. Equations were derived to calculate the rate at which the numbers of viable organisms in a calorimeter decline as the temperature is raised at a constant rate. Vegetative bacteria scanned at 10 degrees C min-1 showed multi-peaked thermograms with four major peaks (denoted m, n, p and q) occurring in the regions 68-73, 77-84, 89-99 and 105-110 degrees C respectively. Exceptions were that peak m (the largest peak) occurred at 79-82 degrees C in Bacillus stearothermophilus and an additional peak, r, was detected in Escherichia coli at 119 degrees C. At temperatures below the main peak m there were major differences in thermograms between species. There was a direct relationship between the onset of thermal denaturation and the thermoresistance of different organisms. Heat-sensitive organisms displayed thermogram features which were absent in the more heat-resistant types. When samples were cooled to 5 degrees C and re-heated, a small endothermic peak, pr, was observed at the same temperature as p. Peaks p and pr were identified as the melting endotherms of DNA. In all vegetative organisms examined, maximum death rates, computed from published D and z values, occurred at temperatures above the onset of thermal denaturation, i.e. cell death and irreversible denaturation of cell components occurred within the same temperature range.

  19. Electron radiography

    Science.gov (United States)

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  20. Effect of Different Filling Materials in Anammox Bacteria Enrichment

    Directory of Open Access Journals (Sweden)

    Dilek ÖZGÜN

    2012-12-01

    Full Text Available Purpose: Anaerobic ammonium oxidation (Anammox is a process that ammonium as electron donor is oxidized to nitrogen gas using nitrite as electron acceptor. Compared to conventional nitrification-denitrification processes, this process is used less oxygen and no organic material (methanol, glucose. However, the slow growth rate of Anammox bacteria (11-30 days is disadvantages. Therefore, batch reactors have been carried out in these bacteria enrichment. In this study continuously operated upflow anaerobic sludge reactor (UASB using different filling materials disposing of sensitive and slow-growing Anammox bacteria out of the system is purposed. Design and Methods: System is operated up-flow column reactor at 2 days hydraulic retention time (HRT in 45 days. In this study, ceramic stones and Linpor filling material are used. Using synthetic wastewater containing ammonium and nitrite, Ar/CO2 anaerobic conditions (95/5% supplied with gas. System is operated at a temperature 253 C in UASB. Temperature, pH, ammonia-nitrogen and nitrite nitrogen are measured. Results: Both filling material reactors are operated in 45 days. Ceramic stones filling reactor is observed quickly reaches 90% were used reactor ammonium removal. The ammonium nitrogen removal was slower in Linpor filling materials reactor. Nitrite removal is reached up to 90% in both the reactor. When compared to the stoichiometric equation in Linpor was composed of large amounts of nitrate. At the end of 25 days the results were similar to ceramic stone filling reactor with Linpor filling material reactors. Conclusions and Original Value: Anammox process as from nitrogen removal processes was discovered in 1995. Anammox bacteria that make up this process due to very low growth rates of microbial bacteria in the system must be kept in the system. Most of the studies in the literature, these bacteria enrichment stage is started instead of a continuous batch reactor system. In this study

  1. Aerobic methanotrophic bacteria of cold ecosystems.

    Science.gov (United States)

    Trotsenko, Yuri A; Khmelenina, Valentina N

    2005-06-01

    This review summarizes the recent advances in understanding the ecophysiological role and structure-function features of methanotrophic bacteria living in various cold ecosystems. The occurrence of methanotrophs in a majority of psychrosphere sites was verified by direct measurement of their methane-utilizing activity, by electron microscopy and immunofluorescent observations, and analyses of specific signatures in cellular phospholipids and total DNAs extracted from environmental samples. Surprisingly, the phenotypic and genotypic markers of virtually all extant methanotrophs were detected in various cold habitats, such as underground waters, Northern taiga and tundra soils, polar lakes and permafrost sediments. Also, recent findings indicated that even after long-term storage in permafrost, some methanotrophs can oxidize and assimilate methane not only at positive but also at subzero temperatures. Pure cultures of psychrophilic and psychrotolerant methanotrophs were isolated and characterized as new genera and species: Methylobacter psychrophilus, Methylosphaera hansonii, Methylocella palustris, Methylocella silvestris, Methylocella tundrae, Methylocapsa acidiphila and Methylomonas scandinavica. However, our knowledge about their adaptive mechanisms and survival in cold ecosystems remains limited and needs to be established using both traditional and molecular microbiological methods.

  2. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  3. Lactic acid bacteria as functional probiotic isolates for inhibiting the growth of Aspergillus flavus, A. parasiticus, A. niger and Penicillium chrysogenum.

    Science.gov (United States)

    Abbaszadeh, S; Tavakoli, R; Sharifzadeh, A; Shokri, H

    2015-12-01

    The aim of this study was to assess the potential of lactic acid bacteria (LAB) such as Lactobacillus acidophilus, L. rhamnosus, L. casei, L. paracasei and Bifidobacterium bifidum to inhibit the outgrowth of some common food-spoiling fungi including Aspergillus niger, A. flavus, A. parasiticus and Penicillium chrysogenum. Bacterial isolates were cultured on Mann Rogosa Sharpe (MRS) broth and liquid cultures and supernatants were prepared. The antifungal activity was tested using the agar well diffusion method. Both liquid culture and supernatant of L. casei isolate exhibited high antifungal activity, followed by L. acidophilus and L. paracasei isolates. The least activity was recorded for the isolates B. bifidum, while the isolate L. rhamnosus was moderately active against tested fungi. The antifungal activity of the supernatants obtained from all probiotic isolates against fungi was significantly less than that of liquid cultures (Pniger and A. parasiticus. These results suggest that probiotic bacteria strains have the ability to prevent the growth of pathogenic and mycotoxigenic fungi as antifungal agents for various biomedical applications. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Childhood, race and spoiling kids

    OpenAIRE

    Oliveira, Fabiana de; Abramowicz, Anete

    2010-01-01

    Atualmente, o campo das discussões que se referem às relações étnico-raciais vem se ampliando em um espaço político-educacional considerável e que contribui para desmontar um forte campo discursivo que se hegemonizou como verdade e que afirmava a existência de uma democracia racial. Este artigo é o resultado de uma pesquisa desenvolvida numa instituição de educação infantil durante um semestre letivo, com visitas diárias. A coleta de dados foi realizada utilizando os seguintes recursos: obser...

  5. Qualidade do substrato minerado de uma área de empréstimo revegetada no distriro federal Quality of a revegeted mine spoil in the federal disrict of Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Studart Corrêa

    2010-08-01

    Full Text Available O uso de resíduos orgânicos tem-se mostrado eficaz para a revegetação de áreas mineradas. Entretanto, dados acerca da qualidade de substratos tratados com resíduos orgânicos são escassos. Dessa forma, este trabalho visou avaliar a qualidade edáfica de um substrato minerado no Distrito Federal que recebeu 250 Mg ha-1 de lodo de esgoto e uma cobertura herbácea estabelecida a partir de sementes. Os atributos edáficos utilizados na avaliação foram densidade de solo, porosidade total, água disponível, resistência mecânica à penetração, ΔpH, CTC, saturação por bases, P disponível, matéria orgânica, abundância e diversidade da macrofauna de solo. Os resultados mostraram que a incorporação do lodo de esgoto e o desenvolvimento de um estrato herbáceo resultaram em melhoria das qualidades química e biológica do substrato exposto pela mineração, mas não alteraram a qualidade física dele. A dose de lodo de esgoto utilizada elevou os valores dos atributos químicos para além dos medidos em solos sob Cerrado nativo. Caso o objetivo da recuperação seja a restauração do ecossistema local, técnicas que melhorem a qualidade física do substrato e não excedam os níveis naturais de fertilidade devem ser desenvolvidas.The use of organic residues has been shown to be effective for the revegetation of mined areas. However, data on the quality of mine spoils treated with organic residues are rather scarce. This study aimed to evaluate the spoil quality of a mined area in the Brazilian Federal District treated with 250 Mg ha-1 of domestic sewage sludge and covered with herbs grown from seeds. The soil attributes used for the evaluation were bulk density, total porosity, available water capacity, soil resistance to penetration, ΔpH, CEC, base saturation, available phosphorus, organic matter content, abundance and diversity of soil macro-fauna. Results show that plowing sewage sludge into the spoil and the establishment of a

  6. Bactericide for sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

    1981-01-01

    The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

  7. Differential staining of bacteria: acid fast stain.

    Science.gov (United States)

    Reynolds, Jackie; Moyes, Rita B; Breakwell, Donald P

    2009-11-01

    Acid-fastness is an uncommon characteristic shared by the genera Mycobacterium (Section 10A) and Nocardia. Because of this feature, this stain is extremely helpful in identification of these bacteria. Although Gram positive, acid-fast bacteria do not take the crystal violet into the wall well, appearing very light purple rather than the deep purple of normal Gram-positive bacteria. (c) 2009 by John Wiley & Sons, Inc.

  8. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  9. Magnetotactic bacteria at the geomagnetic equator

    International Nuclear Information System (INIS)

    Frankel, R.B.; Blakemore, R.P.; Araujo, F.F.T. de; Esquivel, D.M.S.; Danon, J.

    1981-01-01

    Magnetotatic bacteria are observed in freshwater and marine sediments of Fortaleza, Brazil, situated close to the geomagnetic equator. Both South-seeking and North-seeking bacteria are present in roughly equal numbers in the same samples. This observation is consistent with the hypothesis that the vertical component of the geomagnetic field selects the predominant polarity type among magnetotactic bacteria in natural environments. (Author) [pt

  10. Increased production of outer membrane vesicles by cultured freshwater bacteria in response to ultraviolet radiation.

    Science.gov (United States)

    Gamalier, Juliana P; Silva, Thiago P; Zarantonello, Victor; Dias, Felipe F; Melo, Rossana C N

    2017-01-01

    Secretion of membrane vesicles is an important biological process of both eukaryotic and prokaryotic cells. This process has been characterized in pathogenic bacteria, but is less clear in non-pathogenic bacteria from aquatic ecosystems. Here, we investigated, for the first time, the process of formation of outer membranes vesicles (OMVs), nanoscale vesicles extruded from the outer membrane (OM) of gram-negative bacteria, in cultures of freshwater bacteria after exposure or not to ultraviolet radiation (UVR) as an environmental stressor. Non-axenic cultures of freshwater bacteria isolated from a Brazilian aquatic ecosystem (Funil reservoir) were exposed or not to UVR (UVA+UVB) over a 3h period, during which cell density, viability and ultrastructure were analyzed. First, we showed that UVR induce bacterial death. UVR triggered significant negative effect on cell density after 3h of UVR treatment. This decrease was directly associated with cell death as revealed by a cell viability fluorescent probe that enables the distinction of live/dead bacteria. Transmission electron microscopy (TEM) revealed changes indicative of cell death after 3h of UVR exposure, with significant increase of damaged cells compared to the control group. Second, we demonstrated that gram-negative bacteria release OMVs during normal growth and after UVR exposure. OMVs were clearly identified as round, membrane-bound vesicles budding off from the bacterial OM as isolated or clustered vesicles or free in the extracellular medium. Remarkably, quantitative TEM analyses showed that bacteria respond to UVR with increased formation of OMVs. Moreover, while OMVs numbers per intact or damaged cell did not differ in the untreated group, UVR led to a higher vesiculation by bacteria in process of death. This means that degenerating bacteria release OMVs before lysis and that this secretion might be an adaptive/protective response to rapid changes in environmental conditions such as UV radiation. Copyright

  11. Bioactive proteins against pathogenic and spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Sitohy

    2014-10-01

    activities equivalent to or higher than the activity of penicillin, with the basic sub-unit exhibiting the highest activity, followed by glycinin.; β-conglycinin exhibited the lowest level of activity with a MIC of 50, 100 and 1000 μg/mL, respectively. The IC50% values of the basic subunit, glycinin and β-conglycinin, against Listeria monocytogenes, were 15, 16 and 695 μg/mL; against Bacillus subtilis the values were 17, 20, and 612 μg/mL; and against Salmonella Enteritidis the values were 18, 21 and 526 μg/mL, respectively. Transmission electron microscopy images of L. monocytogenes and S. Enteritidis exhibited an increase in cell size and a separation of the cell wall from the cell membrane when treated with glycinin or basic sub-unit. The scanning electron microscopy of B. subtilis indicated signs of an irregular, wrinkled outer surface as well as the fragmentation, adhesion, and aggregation of damaged cells or cellular debris when treated with glycinin or the basic subunits; however not with penicillin. The proliferation of L. monocytogenes, S. Enteritidis and Escherichia coli O157:H7-when artificially inoculated in raw milk ,stored at 4 or 25 °C was significantly (P<0·05 reduced by the glycinin sub-unit and nisin (0·5% w/v; but they were only slightly reduced by β-conglycinin and moderately reduced by lysozyme. The two substances (MSP and MCP exhibited a concentration-dependent inhibitory action against two of the studied bacteria with a minimum inhibitory concentration of approximately 100 µg/mL. The supplementation of raw milk with esterified legume proteins (MSP and MCP has significantly (p < 0.05 reduced the levels of TBC, PBC and PSC in raw milk stored at a temperature of 4 °C. This potentially will delaythe onset of spoilage of by four days. Conclusion: Both glycinin and the basic sub-unit have a more swift antimicrobial action than that of penicillin. Basic sub-units exhibited the highest efficiency at killing bacterial cells, followed by glycinin

  12. Bioenergetics of photoheterotrophic bacteria in the oceans.

    Science.gov (United States)

    Kirchman, David L; Hanson, Thomas E

    2013-04-01

    Photoheterotrophic microbes, such as proteorhodopsin (PR)-based phototrophic (PRP) and aerobic anoxygenic phototrophic (AAP) bacteria, are well known to be abundant in the oceans, potentially playing unique roles in biogeochemical cycles. However, the contribution of phototrophy to the energy requirements of these bacteria has not been quantitatively examined to date. To better understand the implications of photoheterophy in the oceans, we calculated energy benefits and costs of phototrophy and compared net benefits with maintenance costs. Benefits depend on the number of photosynthetic units (PSUs), absorption cross-section area of each PSU as function of wavelength, the in situ light quality, and the energy yield per absorbed photon. For costs we considered the energy required for the synthesis of pigments, amino acids and proteins in each PSU. Our calculations indicate that AAP bacteria harvest more light energy than do PRP bacteria, but the costs of phototrophy are much higher for AAP bacteria. Still, the net energy gained by AAP bacteria is often sufficient to meet maintenance costs, while that is not the case for PRP bacteria except with high light intensities and large numbers of proteorhodopsin molecules per cell. The low costs and simplicity of PR-based phototrophy explain the high abundance of proteorhodopsin genes in the oceans. However, even for AAP bacteria, the net energy yield of phototrophy is apparently too low to influence the distribution of photoheterotrophic bacteria among various marine systems. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  13. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

  14. Isolation and characterization of methanogenic bacteria from ...

    African Journals Online (AJOL)

    Isolation and characterization of methanogenic bacteria from brewery wastewater in Kenya. Sylvia Injete Murunga, Duncan Onyango Mbuge, Ayub Njoroge Gitau, Urbanus Ndungwa Mutwiwa, Ingrid Namae Wekesa ...

  15. Fewer bacteria in warm water

    International Nuclear Information System (INIS)

    Bagh, Lene

    1999-01-01

    There has been many suggestions to how the ideal warm water system should be. Particularly whether warm water containers or heat exchangers in larger houses are the best solutions in order to maintain a water quality with low levels of bacteria. In an investigation made by Statens Byggeforskningsinstitutt (Denmark) regarding ''Bacterial growth in warm water installations with heat exchangers'' there were used several heat exchangers made by Gjelsted and Lund of three of which had HWAT heating cables. The bacterial content was low from these exchangers compared to exchangers with circulation. The article presents promising results from a study where the method was investigated over a longer period in two new larger warm water systems. Some energy conservation aspects are discussed

  16. Modeling Political Populations with Bacteria

    Science.gov (United States)

    Cleveland, Chris; Liao, David

    2011-03-01

    Results from lattice-based simulations of micro-environments with heterogeneous nutrient resources reveal that competition between wild-type and GASP rpoS819 strains of E. Coli offers mutual benefit, particularly in nutrient deprived regions. Our computational model spatially maps bacteria populations and energy sources onto a set of 3D lattices that collectively resemble the topology of North America. By implementing Wright-Fishcer re- production into a probabilistic leap-frog scheme, we observe populations of wild-type and GASP rpoS819 cells compete for resources and, yet, aid each other's long term survival. The connection to how spatial political ideologies map in a similar way is discussed.

  17. Cell Size Regulation in Bacteria

    Science.gov (United States)

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  18. Antioxidant Properties of Probiotic Bacteria.

    Science.gov (United States)

    Wang, Yang; Wu, Yanping; Wang, Yuanyuan; Xu, Han; Mei, Xiaoqiang; Yu, Dongyou; Wang, Yibing; Li, Weifen

    2017-05-19

    Oxidative stress defines a condition in which the prooxidant-antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

  19. Bacteria in the Tatahouine meteorite: nanometric-scale life in rocks.

    Science.gov (United States)

    Gillet, P h; Barrat, J A; Heulin, T h; Achouak, W; Lesourd, M; Guyot, F; Benzerara, K

    2000-02-15

    We present a study of the textural signature of terrestrial weathering and related biological activity in the Tatahouine meteorite. Scanning and transmission electron microscopy images obtained on the weathered samples of the Tatahouine meteorite and surrounding soil show two types of bacteria-like forms lying on mineral surfaces: (1) rod-shaped forms (RSF) about 70-80 nm wide and ranging from 100 nm to 600 nm in length; (2) ovoid forms (OVF) with diameters between 70 and 300 nm. They look like single cells surrounded by a cell wall. Only Na, K, C, O and N with traces of P and S are observed in the bulk of these objects. The chemical analyses and electron diffraction patterns confirm that the RSF and OVF cannot be magnetite or other iron oxides, iron hydroxides, silicates or carbonates. The sizes of the RSF and OVF are below those commonly observed for bacteria but are very similar to some bacteria-like forms described in the Martian meteorite ALH84001. All the previous observations strongly suggest that they are bacteria or their remnants. This conclusion is further supported by microbiological experiments in which pleomorphic bacteria with morphology similar to the OVF and RSF objects are obtained from biological culture of the soil surrounding the meteorite pieces. The present results show that bacteriomorphs of diameter less than 100 nm may in fact represent real bacteria or their remnants.

  20. Sterol Synthesis in Diverse Bacteria.

    Science.gov (United States)

    Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

    2016-01-01

    Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

  1. Electron holography of biological samples.

    Science.gov (United States)

    Simon, P; Lichte, H; Formanek, P; Lehmann, M; Huhle, R; Carrillo-Cabrera, W; Harscher, A; Ehrlich, H

    2008-01-01

    In this paper, we summarise the development of off-axis electron holography on biological samples starting in 1986 with the first results on ferritin from the group of Tonomura. In the middle of the 1990s strong interest was evoked, but then stagnation took place because the results obtained at that stage did not reach the contrast and the resolution achieved by conventional electron microscopy. To date, there exist only a few ( approximately 12) publications on electron holography of biological objects, thus this topic is quite small and concise. The reason for this could be that holography is mostly established in materials science by physicists. Therefore, applications for off-axis holography were powerfully pushed forward in the area of imaging, e.g. electric or magnetic micro- and nanofields. Unstained biological systems investigated by means of off-axis electron holography up to now are ferritin, tobacco mosaic virus, a bacterial flagellum, T5 bacteriophage virus, hexagonal packed intermediate layer of bacteria and the Semliki Forest virus. New results of the authors on collagen fibres and surface layer of bacteria, the so-called S-layer 2D crystal lattice are presented in this review. For the sake of completeness, we will shortly discuss in-line holography of biological samples and off-axis holography of materials related to biological systems, such as biomaterial composites or magnetotactic bacteria.

  2. Efficiency of boiling and four other methods for genomic DNA extraction of deteriorating spore-forming bacteria from milk

    Directory of Open Access Journals (Sweden)

    Jose Carlos Ribeiro Junior

    2016-10-01

    Full Text Available The spore-forming microbiota is mainly responsible for the deterioration of pasteurized milk with long shelf life in the United States. The identification of these microorganisms, using molecular tools, is of particular importance for the maintenance of the quality of milk. However, these molecular techniques are not only costly but also labor-intensive and time-consuming. The aim of this study was to compare the efficiency of boiling in conjunction with four other methods for the genomic DNA extraction of sporulated bacteria with proteolytic and lipolytic potential isolated from raw milk in the states of Paraná and Maranhão, Brazil. Protocols based on cellular lysis by enzymatic digestion, phenolic extraction, microwave-heating, as well as the use of guanidine isothiocyanate were used. This study proposes a method involving simple boiling for the extraction of genomic DNA from these microorganisms. Variations in the quality and yield of the extracted DNA among these methods were observed. However, both the cell lysis protocol by enzymatic digestion (commercial kit and the simple boiling method proposed in this study yielded sufficient DNA for successfully carrying out the Polymerase Chain Reaction (PCR of the rpoB and 16S rRNA genes for all 11 strains of microorganisms tested. Other protocols failed to yield sufficient quantity and quality of DNA from all microorganisms tested, since only a few strains have showed positive results by PCR, thereby hindering the search for new microorganisms. Thus, the simple boiling method for DNA extraction from sporulated bacteria in spoiled milk showed the same efficacy as that of the commercial kit. Moreover, the method is inexpensive, easy to perform, and much less time-consuming.

  3. Thioploca spp: filamentous sulfur bacteria with nitrate vacuoles

    DEFF Research Database (Denmark)

    Jørgensen, BB; Gallardo, VA

    1999-01-01

    communities of large Thioploca species live along the Pacific coast of South America and in other upwelling areas of high organic matter sedimentation with bottom waters poor in oxygen and rich in nitrate. Each cell of these thioplocas harbors a large liquid vacuole which is used as a storage for nitrate...... with a concentration of lip to 506 mM. The nitrate is used as an electron acceptor for sulfide oxidation and the bacteria may grow autotrophically or mixotrophically using acetate or other organic molecules as carbon source. The filaments stretch up into the overlying seawater, from which they take up nitrate...

  4. Differentiation between activity of digestive enzymes of Brachionus calyciflorus and extracellular enzymes of its epizooic bacteria

    Directory of Open Access Journals (Sweden)

    Wilko H. AHLRICHS

    2009-08-01

    Full Text Available The rotifer Brachionus calyciflorus was examined by scanning electron microscopy (SEM for surface-attached, i.e. epizootic, bacteria to ascertain their specific localization and thus find out if we could discern between rotifer and bacterial enzyme activity. The lorica of B. calyciflorus was colonized by one distinct type of bacteria, which originated from the algal culture used for rotifer feeding. The corona, posterior epidermis and foot of all inspected individuals were always without attached bacteria. The density of the attached bacteria was higher with the increasing age of B. calyciflorus: while young individuals were colonized by ~ tens of bacterial cells, older ones had on average hundreds to thousands of attached bacteria. We hypothesize that epizooic bacteria may produce the ectoenzymes phosphatases and β-N-acetylhexosaminidases on the lorica, but not on the corona of B. calyciflorus. Since enzyme activities of epizooic bacteria may influence the values and interpretation of bulk rotifer enzyme activities, we should take the bacterial contribution into account.

  5. Bactericidal activity of bio-synthesized silver nanoparticles against human pathogenic bacteria

    International Nuclear Information System (INIS)

    Abalkhil, Tarad Abdulaziz; Alharbi, Sulaiman Ali; Salmen, Saleh Hussein; Wainwright, Milton

    2017-01-01

    Green synthesis is an attractive and eco-friendly approach to generate potent antibacterial silver nanoparticles (Ag-NPs). Such particles have long been used to fight bacteria and represent a promising tool to overcome the emergence of antibiotic-resistant bacteria. In this study, green synthesis of Ag-NPs was attempted using plant extracts of Aloe vera, Portulaca oleracea and Cynodon dactylon. The identity and size of Ag-NPs was characterized by ultraviolet–visible spectrophotometer and scanning electron microscopy. Monodispersed Ag-NPs were produced with a range of different sizes based on the plant extract used. The bactericidal activity of Ag-NPs against a number of human pathogenic bacteria was determined using the disc diffusion method. The results showed that Gram positive bacteria were more susceptible than Gram negative ones to these antibacterial agents. The minimum inhibitory concentration was determined using the 96- well plate method. Finally, the mechanism by which Ag-NPs affect bacteria was investigated by SEM analysis. Bacteria treated with Ag-NPs were seen to undergo shrinkage and to lose their viability. This study provides evidence for a cheap and effective method for synthesizing potent bactericidal Ag-NPs and demonstrates their effectiveness against human pathogenic bacteria

  6. Electrons, Electronic Publishing, and Electronic Display.

    Science.gov (United States)

    Brownrigg, Edwin B.; Lynch, Clifford A.

    1985-01-01

    Provides a perspective on electronic publishing by distinguishing between "Newtonian" publishing and "quantum-mechanical" publishing. Highlights include media and publishing, works delivered through electronic media, electronic publishing and the printed word, management of intellectual property, and recent copyright-law issues…

  7. Potential effects of bacteria on radionuclide transport from a Swedish high level nuclear waste repository

    International Nuclear Information System (INIS)

    Pedersen, K.

    1990-01-01

    Microorganisms can influence radionuclide migration if their concentration are high in comparison with other organic particles. Data on the numbers of microorganisms in undisturbed ground-water have been collected. The average number of cells in the samples from 17 levels in 5 boreholes was 3.0 x 10 5 cells ml -1 . A biofilm experiment indicated an active microbial rock surface population. Radiographic uptake experiments suggest inactive bulk water populations. The bulk water microbial cells in deep ground water might then be inactive cells detached from active biofilms. Enrichment cultures for anaerobic bacteria demonstrated the presence of anaerobic bacteria capable of growth on C-1 compounds with hydrogen and carbon dioxide, presumably methanogenic bacteria. Further, growth in enrichment cultures with sulphate as electron-acceptor and lactate as carbon source proved dissimilatory sulphate reducing bacteria to be present. (author)

  8. Characterization of Bacteria Isolation of Bacteria from Pinyon Rhizosphere,

    Science.gov (United States)

    2016-01-01

    Two hundred and fifty bacterial strains were isolated from pinyon rhizosphere and screened for biosurfactants production. Among them, six bacterial strains were selected for their potential to produce biosurfactants using two low cost wastes, crude glycerol and lactoserum, as raw material. Both wastes were useful for producing biosurfactants because of their high content in fat and carbohydrates. The six strains were identified by 16S rDNA with an identity percentage higher than 95%, three strains belonged to Enterobacter sp., Pseudomonas aeruginosa, Bacillus pumilus and Rhizobium sp. All strains assayed were able to grow and showed halos around the colonies as evidence of biosurfactants production on Cetyl Trimethyl Ammonium Bromide agar with crude glycerol and lactoserum as substrate. In a mineral salt liquid medium enriched with both wastes, the biosurfactants were produced and collected from free cell medium after 72 h incubation. The biosurfactants produced reduced the surface tension from 69 to 30 mN/m with an emulsification index of diesel at approximately 60%. The results suggest that biosurfactants produced by rhizosphere bacteria from pinyon have promising environmental applications.

  9. Quantifying the effect of water activity and storage temperature on single spore lag times of three moulds isolated from spoiled bakery products.

    Science.gov (United States)

    Dagnas, Stéphane; Gougouli, Maria; Onno, Bernard; Koutsoumanis, Konstantinos P; Membré, Jeanne-Marie

    2017-01-02

    The inhibitory effect of water activity (a w ) and storage temperature on single spore lag times of Aspergillus niger, Eurotium repens (Aspergillus pseudoglaucus) and Penicillium corylophilum strains isolated from spoiled bakery products, was quantified. A full factorial design was set up for each strain. Data were collected at levels of a w varying from 0.80 to 0.98 and temperature from 15 to 35°C. Experiments were performed on malt agar, at pH5.5. When growth was observed, ca 20 individual growth kinetics per condition were recorded up to 35days. Radius of the colony vs time was then fitted with the Buchanan primary model. For each experimental condition, a lag time variability was observed, it was characterized by its mean, standard deviation (sd) and 5 th percentile, after a Normal distribution fit. As the environmental conditions became stressful (e.g. storage temperature and a w lower), mean and sd of single spore lag time distribution increased, indicating longer lag times and higher variability. The relationship between mean and sd followed a monotonous but not linear pattern, identical whatever the species. Next, secondary models were deployed to estimate the cardinal values (minimal, optimal and maximal temperatures, minimal water activity where no growth is observed anymore) for the three species. That enabled to confirm the observation made based on raw data analysis: concerning the temperature effect, A. niger behaviour was significantly different from E. repens and P. corylophilum: T opt of 37.4°C (standard deviation 1.4°C) instead of 27.1°C (1.4°C) and 25.2°C (1.2°C), respectively. Concerning the a w effect, from the three mould species, E. repens was the species able to grow at the lowest a w (aw min estimated to 0.74 (0.02)). Finally, results obtained with single spores were compared to findings from a previous study carried out at the population level (Dagnas et al., 2014). For short lag times (≤5days), there was no difference between lag

  10. The usage of sulfide and thiosulfate ions by purple non-sulfur bacteria Rhodopseudomonas yavorovii

    Directory of Open Access Journals (Sweden)

    O. V. Tarabas

    2017-07-01

    Full Text Available This article covers the patterns of oxidation of sulfide and thiosulfate ions by bacteria Rhodopseudomonas yavorovii Ya-2016 under different cultivation conditions. In the environments with 1.4–5.6 мМ Na2S2O3, R. yavorovii Ya-2016 bacteria accumulated biomass of 1.4–1.6 g/l, which was higher than biomass (1.2-0.6 g/l accumulated by the bacteria with the same concentrations of Na2S × 9H2O. The efficiency of oxidation of 1.4, 2.8, 5.6 мМ sulfide- and thiosulfate-ions as donors of electrons by the bacteria equaled 97.4, 42.6, 18.7 and 68.8, 28.0, 3.7%, respectively. As a result of bacterial oxidation of 1.4 мМ hydrogen sulfide and sodium thiosulphate in the environment accumulation of 0.13–1.30 мМ sulfate-ions occurs, and the element sulfur becomes an intermediate metabolite in the environment with Na2S×9H2O. R. yavorovii Ya-2016 bacteria are capable of using sulfate-ions as a single source of sulfate at increase in photptrophs. In the environment with 2.5 мМ sulfate-ions concentration the bacteria biomass was 1.4 g/l, the bacteria assimilated 17.7% of sulfates. Because purple non-sulfur bacteria R. yavorovii Ya-2016 are capable of using sulfide-ions as donors of electrons of anoxygenic photosynthesis and using sulfate-ions as a single source of sulfate, they could be successfully used in the technologies of remediating the environment from compounds of sulfur.

  11. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.

    2006-01-01

    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods...

  12. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  13. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  14. Analyzing Arthropods for the Presence of Bacteria

    OpenAIRE

    Andrews, Elizabeth S.

    2013-01-01

    Bacteria within arthropods can be identified using culture-independent methods. This unit describes protocols for surface sterilization of arthropods, DNA extraction of whole bodies and tissues, touchdown PCR amplification using 16S rDNA general bacteria primers and profiling the bacterial community using denaturing gradient gel electrophoresis.

  15. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B T; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  16. Ecophysiology of terminal carbon metabolizing bacteria in anoxic sedimentary environments

    International Nuclear Information System (INIS)

    Phelps, T.J.

    1985-01-01

    Chemical, radiotracer, and microbiological experiments were used to understand the transformation of simple carbon compounds by anaerobic bacteria in diverse aquatic sediments and laboratory cultures. The mildly acidic sediments of Knack Lake (pH 6.2), displayed low rates of organic decomposition, and methane formation occurred almost exclusively from acetate. Low pH inhibited methanogenesis and organic decomposition. Fall turnover in Lake Mendota sediments was associated with dramatic changes in environmental parameters including: elevated concentrations of sulfate and carbon metabolites, increased rates of sulfate reduction, decreased levels of methanogenesis, increased ratio (by viable counts) of sulfate reducing to methanogenic bacteria, and higher 14 CO 2 / 14 C 4 + 14 CO 2 gas ratios produced during the biodegradation of 14 C-carbon substrates (e.g., acetate and methanol). Hydrogen consumption by sulfate reducers in Lake Mendota sediments and in co-cultures of Desulfovibrio vulgaris and Methanosarcina barkeri led to an alteration in the carbon and electron flow pathway resulting in increased CO 2 , sulfide production, and decreased methanogenesis. These data agreed with the environmental observations in Lake Mendota that high sulfate concentrations resulted in higher ratios of CO 2 /CH 4 produced from the degradation of organic matter. A new glycine-metabolizing acetogenic species was isolated and characterized from Knaack Lake which further extended the known diversity of anaerobic bacteria in nature

  17. Catabolism of lysine by mixed rumen bacteria

    International Nuclear Information System (INIS)

    Onodera, Ryoji; Kandatsu, Makoto.

    1975-01-01

    Metabolites arising from the catabolism of lysine by the mixed rumen bacteria were chromatographically examined by using radioactive lysine. After 6 hr incubation, 241 nmole/ml of lysine was decomposed to give ether-soluble substances and CO 2 by the bacteria and 90 nmole/ml of lysine was incorporated unchanged into the bacteria. delta-Aminovalerate, cadaverine or pipecolate did not seem to be produced from lysine even after incubation of the bacteria with addition of those three amino compounds to trap besides lysine and radioactive lysine. Most of the ether-soluble substances produced from radioactive lysine was volatile fatty acids (VFAs). Fractionation of VFAs revealed that the peaks of butyric and acetic acids coincided with the strong radioactive peaks. Small amounts of radioactivities were detected in propionic acid peak and a peak assumed to be caproic acid. The rumen bacteria appeared to decompose much larger amounts of lysine than the rumen ciliate protozoa did. (auth.)

  18. Biodiversity of Bacteria Isolated from Different Soils

    Directory of Open Access Journals (Sweden)

    Fatma YAMAN

    2017-01-01

    Full Text Available The aim of this study was to determine the biodiversity of PHB producing bacteria isolated from soils where fruit and vegetable are cultivated (onion, grape, olive, mulberry and plum in Aydın providence. Morphological, cultural, biochemical, and molecular methods were used for bacteria identification. These isolated bacteria were identified by 16S rRNA sequencing and using BLAST. The following bacteria Bacillus thuringiensis (6, Bacillus cereus (8, Bacillus anthrachis (1, Bacillus circulans (1, Bacillus weihenstephanensis (1, Pseudomonas putida (1, Azotobacter chroococcum (1, Brevibacterium frigoritolerans (1, Burkholderia sp. (1, Staphylococcus epidermidis (1, Streptomyces exfoliatus (1, Variovorax paradoxus (1 were found. The Maximum Likelihood method was used to produce a molecular phylogenetic analysis and a phylogenetic tree was constructed. These bacteria can produce polyhydroxybutyrate (PHB which is an organic polymer with commercial potential as a biodegradable thermoplastic. PHB can be used instead of petrol derivated non-degradable plastics. For this reason, PHB producing microorganisms are substantial in industry.

  19. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  20. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette

    2010-01-01

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

  1. Hyphae colonizing bacteria associated with Penicillium bilaii

    DEFF Research Database (Denmark)

    Ghodsalavi, Behnoushsadat

    shown that mycorrhizal helper bacteria presenting in mycorrhizal fungi could stimulate fungal growth, promote establishment of root-fungus symbiosis and enhance plant production. But it is unknown if the comparable relationship exist between the non-mycorrhizal fungus P. bilaii and its hyphae associated...... bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... stimulating bacteria with the perspective of promoting efficiency of Jumpstart in soil – plant system. For this purpose, most of the work within the current project was carried out by development of suitable model systems by mimicking the natural soil habitat to reach to the reliable performance in soil...

  2. [Unique properties of highly radioresistant bacteria].

    Science.gov (United States)

    Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

    2000-01-01

    In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

  3. Physiology and genetics of sulfur-oxidizing bacteria.

    Science.gov (United States)

    Friedrich, C G

    1998-01-01

    Reduced inorganic sulfur compounds are oxidized by members of the domains Archaea and Bacteria. These compounds are used as electron donors for anaerobic phototrophic and aerobic chemotrophic growth, and are mostly oxidized to sulfate. Different enzymes mediate the conversion of various reduced sulfur compounds. Their physiological function in sulfur oxidation is considered (i) mostly from the biochemical characterization of the enzymatic reaction, (ii) rarely from the regulation of their formation, and (iii) only in a few cases from the mutational gene inactivation and characterization of the resulting mutant phenotype. In this review the sulfur-metabolizing reactions of selected phototrophic and of chemotrophic prokaryotes are discussed. These comprise an archaeon, a cyanobacterium, green sulfur bacteria, and selected phototrophic and chemotrophic proteobacteria. The genetic systems are summarized which are presently available for these organisms, and which can be used to study the molecular basis of their dissimilatory sulfur metabolism. Two groups of thiobacteria can be distinguished: those able to grow with tetrathionate and other reduced sulfur compounds, and those unable to do so. This distinction can be made irrespective of their phototrophic or chemotrophic metabolism, neutrophilic or acidophilic nature, and may indicate a mechanism different from that of thiosulfate oxidation. However, the core enzyme for tetrathionate oxidation has not been identified so far. Several phototrophic bacteria utilize hydrogen sulfide, which is considered to be oxidized by flavocytochrome c owing to its in vitro activity. However, the function of flavocytochrome c in vivo may be different, because it is missing in other hydrogen sulfide-oxidizing bacteria, but is present in most thiosulfate-oxidizing bacteria. A possible function of flavocytochrome c is discussed based on biophysical studies, and the identification of a flavocytochrome in the operon encoding enzymes involved

  4. Electron detector

    International Nuclear Information System (INIS)

    Hashimoto, H.; Mogami, A.

    1975-01-01

    A device for measuring electron densities at a given energy level in an electron beam or the like having strong background noise, for example, in the detection of Auger electric energy spectrums is described. An electron analyzer passes electrons at the given energy level and at the same time electrons of at least one adjacent energy level. Detecting means associated therewith produce signals indicative of the densities of the electrons at each energy level and combine these signals to produce a signal indicative of the density of the electrons of the given energy level absent background noise

  5. Comparative cytotoxicity of periodontal bacteria

    International Nuclear Information System (INIS)

    Stevens, R.H.; Hammond, B.F.

    1988-01-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species

  6. Tape Cassette Bacteria Detection System

    Science.gov (United States)

    1973-01-01

    The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

  7. Antioxidant Properties of Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2017-05-01

    Full Text Available Oxidative stress defines a condition in which the prooxidant–antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells’ viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

  8. Metabolic Flexibility of Sulfate Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Caroline M. Plugge

    2011-05-01

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

  9. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  10. Electron/electron acoustic instability

    International Nuclear Information System (INIS)

    Gary, S.P.

    1987-01-01

    The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

  11. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  12. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  13. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1995-01-01

    Microsensor studies show that the marine environment in the size scale of bacteria is physically and chemically very different from the macroenvironment. The microbial world of the sediment-water interface is thus dominated by water viscosity and steep diffusion gradients. Because of the diverse...... metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  14. Labelling of bacteria with indium chelates

    International Nuclear Information System (INIS)

    Kleinert, P.; Pfister, W.; Endert, G.; Sproessig, M.

    1985-01-01

    The indium chelates were prepared by reaction of radioactive indiumchloride with 10 μg oxine, 15 μg tropolone and 3 mg acetylacetone, resp. The formed chelates have been incubated with 10 9 germs/ml for 5 minutes, with labelling outputs from 90 to 95%. Both gram-positive (Streptococcus, Staphylococcus) and gram-negative bacteria (Escherichia coli) can be labelled. The reproductive capacity of the bacteria was not impaired. The application of indium labelled bacteria allows to show the distribution of microorganisms within the living organism and to investigate problems of bacterial adherence. (author)

  15. Mortality of fecal bacteria in seawater

    International Nuclear Information System (INIS)

    Garcia-Lara, J.; Menon, P.; Servais, P.; Billen, G.

    1991-01-01

    The authors propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloracetic acid-insoluble fraction in water samples to which [ 3 H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, they found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate

  16. Pu sorption to activated conglomerate anaerobic bacteria

    International Nuclear Information System (INIS)

    Sasaki, Takayuki; Kudo, Akira

    2001-01-01

    The sorption of Pu to the anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after long dormant period was investigated. After 4 h at neutral pH, the distribution coefficient (K d ) between bacteria and aqueous phase at 308 and 278 K had around 10 3 to 10 4 . After over 5 days, however, the K d at only 308 K had increased to over 10 5 . Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. (author)

  17. Bacteria Culture Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/bacteriaculturetest.html Bacteria Culture Test To use the sharing features on this page, please enable JavaScript. What is a Bacteria Culture Test? Bacteria are a large group of ...

  18. Electronic emission and electron guns

    International Nuclear Information System (INIS)

    Roy, Amitava

    2010-01-01

    This paper reviews the process of electron emission from metal surface. Although electrons move freely in conductors like metals, they normally do not leave the metal without some manipulation. In fact, heating and bombardment are the two primary ways in which electrons are emitted through the use of a heating element behind the cathode (termed thermionic emission) or as a result of bombardment with a beam of electrons, ions, or metastable atoms (termed secondary emission). Another important emission mechanism called Explosive Electron Emission (EEE) is also often used in various High Voltage Pulse Power Systems to generate very high current (few hundreds of kA) pulsed electron beams. The electron gun is the device in that it shoots off a continuous (or pulsed) stream of electrons. A brief idea about the evolution of the electron gun components and their basis of functioning are also discussed. (author)

  19. Selection of electrogenic bacteria for microbial fuel cell in removing Victoria blue R from wastewater.

    Science.gov (United States)

    Chen, Chih-Yu; Tsai, Teh-Hua; Wu, Pei-Ssu; Tsao, Shuo-En; Huang, Yu-Shan; Chung, Ying-Chien

    2018-01-28

    This study was conducted to select electrogenic bacteria from wastewater sludge. Phylogenetic analysis revealed that Proteobacteria was the dominant phylum in the microbial fuel cell (MFC) during the decomposition process of organic pollutants. Five culturable bacteria strains - namely, Bacillus subtilis, Flavobacterium sp., Aeromonas hydrophila, Citrobacter freundii, and Stenotrophomonas sp. - have a double potential in dye removal and electricity generation. We inoculated the mixed electrogenic bacteria at a specific ratio and treated them with a triphenylmethane dye, Victoria blue R (VBR), to evaluate their electricity generation ability for the artificial and real wastewater. The results of the VBR shock-loading experiment indicated that the inoculated MFC could adapt to shock loading in 1-2 days and exhibited high removal efficiency (95-100%) for 100-800 mg L -1 VBR with a power density of 8.62 ± 0.10 to 34.81 ± 0.25 mW m -2 . The selected electrogenic bacteria in the MFC could use VBR as only electron donor for power generation. The matrix effects of the real wastewater on VBR removal and electricity generation of MFC were insignificant. VBR degradation by the electrogenic bacteria involves a stepwise demethylation process to yield partially dealkylated VBR species. In addition, these results demonstrate the feasibility of inoculating culturable bacteria strains to develop an efficient MFC for purifying wastewater.

  20. Analysis of magnetite crystals and inclusion bodies inside magnetotactic bacteria from different environmental locations

    Science.gov (United States)

    Oestreicher, Z.; Lower, B.; Lower, S.; Bazylinski, D. A.

    2011-12-01

    Biomineralization occurs throughout the living world; a few common examples include iron oxide in chiton teeth, calcium carbonate in mollusk shells, calcium phosphate in animal bones and teeth, silica in diatom shells, and magnetite crystals inside the cells of magnetotactic bacteria. Biologically controlled mineralization is characterized by biominerals that have species-specific properties such as: preferential crystallographic orientation, consistent particle size, highly ordered spatial locations, and well-defined composition and structure. It is well known that magnetotactic bacteria synthesize crystals of magnetite inside of their cells, but how they mineralize the magnetite is poorly understood. Magnetosomes have a species-specific morphology that is due to specific proteins involved in the mineralization process. In addition to magnetite crystals, magnetotactic bacteria also produce inclusion bodies or granules that contain different elements, such as phosphorus, calcium, and sulfur. In this study we used the transmission electron microscope to analyze the structure of magnetite crystals and inclusion bodies from different species of magnetotactic bacteria in order to determine the composition of the inclusion bodies and to ascertain whether or not the magnetite crystals contain elements other than iron and oxygen. Using energy dispersive spectroscopy we found that different bacteria from different environments possess inclusion bodies that contain different elements such as phosphorus, calcium, barium, magnesium, and sulfur. These differences may reflect the conditions of the environment in which the bacteria inhabit.

  1. Propionate oxidation by and methanol inhibition of anaerobic ammonium-oxidizing bacteria.

    Science.gov (United States)

    Güven, Didem; Dapena, Ana; Kartal, Boran; Schmid, Markus C; Maas, Bart; van de Pas-Schoonen, Katinka; Sozen, Seval; Mendez, Ramon; Op den Camp, Huub J M; Jetten, Mike S M; Strous, Marc; Schmidt, Ingo

    2005-02-01

    Anaerobic ammonium oxidation (anammox) is a recently discovered microbial pathway and a cost-effective way to remove ammonium from wastewater. Anammox bacteria have been described as obligate chemolithoautotrophs. However, many chemolithoautotrophs (i.e., nitrifiers) can use organic compounds as a supplementary carbon source. In this study, the effect of organic compounds on anammox bacteria was investigated. It was shown that alcohols inhibited anammox bacteria, while organic acids were converted by them. Methanol was the most potent inhibitor, leading to complete and irreversible loss of activity at concentrations as low as 0.5 mM. Of the organic acids acetate and propionate, propionate was consumed at a higher rate (0.8 nmol min(-1) mg of protein(-1)) by Percoll-purified anammox cells. Glucose, formate, and alanine had no effect on the anammox process. It was shown that propionate was oxidized mainly to CO(2), with nitrate and/or nitrite as the electron acceptor. The anammox bacteria carried out propionate oxidation simultaneously with anaerobic ammonium oxidation. In an anammox enrichment culture fed with propionate for 150 days, the relative amounts of anammox cells and denitrifiers did not change significantly over time, indicating that anammox bacteria could compete successfully with heterotrophic denitrifiers for propionate. In conclusion, this study shows that anammox bacteria have a more versatile metabolism than previously assumed.

  2. Treatment of hexavalent chrome by bacteria. Saikin ni yoru rokka kuromu no shori

    Energy Technology Data Exchange (ETDEWEB)

    Otake, H [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1993-08-01

    A biological reduction method in which hazardous hexavalent chrome is reduced by bacteria is explained as one of the bioremediation technologies. Those bacteria are separated from active sludge in the urban sewage treatment plant. The hexavalent chrome-reducing bacteria were isolated by cultivating the sludge. They were Enterobacter cloacae which are intestinal bacteria. Then, they were named HO1 stock. As a result of analyzing the reduction mechanism, it was made clear that the function is localized in the cellular endosporium and that the reduction is made by utilizing the electronic transfer system of endosporium. Under both aerobic and anaerobic conditions, they convert the hexavalent chrome into the trivalent chrome outside the cells. As a result of test, it was known that 5mM hexavalent chrome can be treated in one day. A quick reduction was confirmed also through an experiment in which carbon source was added to the industrial wastewater. If used for the treatment of sludge/water contaminated by hexavalent chrome, the present reduction by bacteria has the following advantages: The highest reduction rate is given near pH=7 at ordinary temperatures. It is not necessary to add chemicals. Energy is not needed. It is a disadvantageous fact that the present bacteria, if exposed to oxygen, become inactive. 18 refs., 5 figs.

  3. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa; Torres Sevilla, Galo Andres; Diaz Cordero, Marlon Steven

    2017-01-01

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces

  4. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    "[to] promote the understanding and, acceptance of and growth in the number of electronic transactions .... Chapter III of the ECT Act is based on the UNCITRAL Model Law on Electronic. Commerce ... Communications Technology Law 146. 22.

  5. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  6. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  7. Electronic Commerce

    OpenAIRE

    Slavko Đerić

    2016-01-01

    Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks...

  8. Flow cytometry, fluorescent probes, and flashing bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.

    2002-01-01


    Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk,

  9. Effect of leukocyte hydrolases on bacteria

    International Nuclear Information System (INIS)

    Cohen, D.; Michel, J.; Ferne, M.; Bergner-Rabinowitz, S.; Ginsburg, I.

    1979-01-01

    Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites

  10. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  11. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    Lahtinen, Sampo

    2012-01-01

    "Updated with the substantial progress made in lactic acid and bacteria research since the third edition, this fourth volume discusses improved insights in genetics and new molecular biological techniques...

  12. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

  13. Do bacteria, not fish, produce 'fish kairomone'?

    NARCIS (Netherlands)

    Ringelberg, J.; Van Gool, E.

    1998-01-01

    Fish-associated chemicals enhance phototactic downward swimming in Daphnia. If perch were treated with the antibiotic ampicillin, this enhancement was significantly decreased. Therefore, not fish, but bacteria associated with fish, seem to produce this kairomone. [KEYWORDS: Diel vertical migration;

  14. Bacteria-mediated bisphenol A degradation.

    Science.gov (United States)

    Zhang, Weiwei; Yin, Kun; Chen, Lingxin

    2013-07-01

    Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

  15. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  16. Interactions between phototrophic bacteria in marine sediments

    NARCIS (Netherlands)

    de Wit, Rutger

    1989-01-01

    Phototrophic bacteria are the most consicious organisms occuring in laminated microbial sediment ecosystems (microbial mats). In the Waddensea area ecosystems consisting of a toplayer of the cyanobacterium Microleus chthonoplastes overlying a red layer of the purple sulfur bacterium Thiocapsa

  17. Electronic Publishing.

    Science.gov (United States)

    Lancaster, F. W.

    1989-01-01

    Describes various stages involved in the applications of electronic media to the publishing industry. Highlights include computer typesetting, or photocomposition; machine-readable databases; the distribution of publications in electronic form; computer conferencing and electronic mail; collaborative authorship; hypertext; hypermedia publications;…

  18. Extracellular Electron Transport Coupling Biogeochemical Processes Centimeters

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Fossing, Henrik; Christensen, Peter Bondo

    2010-01-01

    of the oxygen uptake in laboratory incubations of initially homogenized and stabilized sediment. Using microsensors and process rate measurements we further investigated the effect of the electric currents on sediment biogeochemistry. Dissolved sulfide readily donated electrons to the networks and could...... confirmed the depth range of the electric communication and indicated donation of electrons directly from organotrophic bacteria. The separation of oxidation and reduction processes created steep pH gradients eventually causing carbonate precipitation at the surface. The results indicate that electron...... exchanging organisms have major biogeochemical importance as they allow widely separated electron donors and acceptors to react with one another....

  19. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.

    1982-01-01

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  20. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  1. Extracellular deoxyribonuclease production by periodontal bacteria.

    Science.gov (United States)

    Palmer, L J; Chapple, I L C; Wright, H J; Roberts, A; Cooper, P R

    2012-08-01

    Whilst certain bacteria have long been known to secrete extracellular deoxyribonuclease (DNase), the purpose in microbial physiology was unclear. Recently, however, this enzyme has been demonstrated to confer enhanced virulence, enabling bacteria to evade the host's immune defence of extruded DNA/chromatin filaments, termed neutrophil extracellular traps (NETs). As NETs have recently been identified in infected periodontal tissue, the aim of this study was to screen periodontal bacteria for extracellular DNase activity. To determine whether DNase activity was membrane bound or secreted, 34 periodontal bacteria were cultured in broth and on agar plates. Pelleted bacteria and supernatants from broth cultures were analysed for their ability to degrade DNA, with relative activity levels determined using an agarose gel electrophoresis assay. Following culture on DNA-supplemented agar, expression was determined by the presence of a zone of hydrolysis and DNase activity related to colony size. Twenty-seven bacteria, including red and orange complex members Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Streptococcus constellatus, Campylobacter rectus and Prevotella nigrescens, were observed to express extracellular DNase activity. Differences in DNase activity were noted, however, when bacteria were assayed in different culture states. Analysis of the activity of secreted DNase from bacterial broth cultures confirmed their ability to degrade NETs. The present study demonstrates, for the first time, that DNase activity is a relatively common property of bacteria associated with advanced periodontal disease. Further work is required to determine the importance of this bacterial DNase activity in the pathogenesis of periodontitis. © 2011 John Wiley & Sons A/S.

  2. Occurrence of diazotrophic bacteria in Araucaria angustifolia

    OpenAIRE

    Neroni,Rafaela de Fátima; Cardoso,Elke Jurandy Bran Nogueira

    2007-01-01

    Araucaria angustifolia is an environmentally threatened tree and the whole biota of the Araucaria Forest should be investigated with the aim of its preservation. Diazotrophic bacteria are extremely important for the maintenance of ecosystems, but they have never been studied in Araucaria Forests. In this study, diazotrophic bacteria were isolated from Araucaria roots and soil, when grown in semi-specific, semi-solid media. The diazotrophic character of some recovered isolates could be confirm...

  3. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  4. Simple method for generating adjustable trains of picosecond electron bunches

    Directory of Open Access Journals (Sweden)

    P. Muggli

    2010-05-01

    Full Text Available A simple, passive method for producing an adjustable train of picosecond electron bunches is demonstrated. The key component of this method is an electron beam mask consisting of an array of parallel wires that selectively spoils the beam emittance. This mask is positioned in a high magnetic dispersion, low beta-function region of the beam line. The incoming electron beam striking the mask has a time/energy correlation that corresponds to a time/position correlation at the mask location. The mask pattern is transformed into a time pattern or train of bunches when the dispersion is brought back to zero downstream of the mask. Results are presented of a proof-of-principle experiment demonstrating this novel technique that was performed at the Brookhaven National Laboratory Accelerator Test Facility. This technique allows for easy tailoring of the bunch train for a particular application, including varying the bunch width and spacing, and enabling the generation of a trailing witness bunch.

  5. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum as solidif......Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... as solidifying agents, and enumerated bacteria from seawater and algal exudates. We tested if culturability could be influenced by addition of quorum sensing signals (AHLs). All plates were incubated at 15°C. Bacterial counts (CFU/g) from algal exudates from brown algae were highest on media containing algal...... polymers. In general, bacteria isolated from algal exudates preferred more rich media than bacteria isolated from seawater. Overall, culturability ranged from 0.01 to 0.8% as compared to total cell count. Substitution of agar with gellan gum increased the culturability of seawater bacteria approximately...

  6. Antibiotic-resistant bacteria in drinking water.

    Science.gov (United States)

    Armstrong, J L; Shigeno, D S; Calomiris, J J; Seidler, R J

    1981-08-01

    We analyzed drinking water from seven communities for multiply antibiotic-resistant (MAR) bacteria (bacteria resistant to two or more antibiotics) and screened the MAR bacterial isolates obtained against five antibiotics by replica plating. Overall, 33.9% of 2,653 standard plate count bacteria from treated drinking waters were MAR. Two different raw water supplies for two communities carried MAR standard plate count bacteria at frequencies of 20.4 and 18.6%, whereas 36.7 and 67.8% of the standard plate count populations from sites within the respective distribution systems were MAR. Isolate identification revealed that MAR gram-positive cocci (Staphylococcus) and MAR gram-negative, nonfermentative rods (Pseudomonas, Alcaligenes, Moraxella-like group M, and Acinetobacter) were more common in drinking waters than in untreated source waters. Site-to-site variations in generic types and differences in the incidences of MAR organisms indicated that shedding of MAR bacteria living in pipelines may have contributed to the MAR populations in tap water. We conclude that the treatment of raw water and its subsequent distribution select for standard plate count bacteria exhibiting the MAR phenotype.

  7. Monitoring structural transformation of hydroxy-sulphate green rust in the presence of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Abdelmoula, M.; Zegeye, A.; Jorand, F.; Carteret, C.

    2006-01-01

    The activities of bacterial consortia enable organisms to maximize their metabolic capabilities. This article assesses the synergetic relationship between iron reducing bacteria (IRB), Shewanella putrefaciens and sulphate reducing bacteria (SRB) Desulfovibrio alaskensis. Thus, the aim of this study was first to form a biogenic hydroxy-sulpahte green rust GR2(SO 4 -2 ) through the bioreduction of lepidocrocite by S. putrefaciens and secondly to investigate if sulfate anions intercalated in the biogenic GR2(SO 4 -2 ) could serve as final electron acceptor for a sulfate reducing bacterium, D. alaskensis. The results indicate that the IRB lead to the formation of GR2(SO 4 -2 ) and this mineral serve as an electron acceptor for SRB. GR2(SO 4 -2 ) precipitation and its transformation was demonstrated by using X-ray diffraction (DRX), Moessbauer spectroscopy (TMS) and transmission electron spectroscopy (TEM). These observations point out the possible acceleration of steel corrosion in marine environment in presence of IRB/SRB consortia.

  8. Characterization of technetium(vII) reduction by cell suspensions of thermophilic bacteria and archaea.

    Science.gov (United States)

    Chernyh, Nikolay A; Gavrilov, Sergei N; Sorokin, Vladimir V; German, Konstantin E; Sergeant, Claire; Simonoff, Monique; Robb, Frank; Slobodkin, Alexander I

    2007-08-01

    Washed cell suspensions of the anaerobic hyperthermophilic archaea Thermococcus pacificus and Thermoproteus uzoniensis and the anaerobic thermophilic gram-positive bacteria Thermoterrabacterium ferrireducens and Tepidibacter thalassicus reduced technetium [(99)Tc(VII)], supplied as soluble pertechnetate with molecular hydrogen as an electron donor, forming highly insoluble Tc(IV)-containing grayish-black precipitate. Apart from molecular hydrogen, T. ferrireducens reduced Tc(VII) with lactate, glycerol, and yeast extract as electron donors, and T. thalassicus reduced it with peptone. Scanning electron microscopy and X-ray microanalysis of cell suspensions of T. ferrireducens showed the presence of Tc-containing particles attached to the surfaces of non-lysed cells. This is the first report on the reduction in Tc(VII) by thermophilic microorganisms of the domain Bacteria and by archaea of the phylum Euryarchaeota.

  9. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-09-08

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces. The stickers can be wrappable, placed on surfaces, glued on walls or mirrors or wood or stone, and have electronics (112, 122, 132) which may or may not be ultrathin. Packaging for the electronic sticker can use polymer on cellulose manufacturing and/or three dimensional (3-D) printing. The electronic stickers may provide lighting capability, sensing capability, and/or recharging capabilities.

  10. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  11. Insights into the genome of large sulfur bacteria revealed by analysis of single filaments

    DEFF Research Database (Denmark)

    Mussmann, Marc; Hu, Fen Z.; Richter, Michael

    2007-01-01

    Beggiatoa to overcome non-overlapping availabilities of electron donors and acceptors while gliding between oxic and sulfidic zones. The first look into the genome of these filamentous sulfur-oxidizing bacteria substantially deepens the understanding of their evolution and their contribution to sulfur......Marine sediments are frequently covered by mats of the filamentous Beggiatoa and other large nitrate-storing bacteria that oxidize hydrogen sulfide using either oxygen or nitrate, which they store in intracellular vacuoles. Despite their conspicuous metabolic properties and their biogeochemical...

  12. Enhanced bioremoval of lead by earthworm-Lumbricus terrestris co-cultivated with bacteria-Klebsiella variicola.

    Science.gov (United States)

    Das, Anamika; Osborne, Jabez W

    2017-10-01

    Lead is a toxic heavy metal having devastating effects on the environment. The current study was focussed on bioremoval of lead using earthworm and lead resistant bacteria. Earthworms were subjected to various concentrations of lead in the soil bioaugmented with lead resistant bacteria (VITMVCJ1) to enhance the uptake of lead from the contaminated soil. Significant increase was observed in the length and body weight of the earthworms supplemented with lead resistant bacteria. Similarly, there was a substantial increase in the locomotion rate of the earthworms treated with lead resistant bacteria in comparison with the control. The gut micro flora of bacterial treated earthworms had increased number of bacterial cells than the untreated earthworms. The histopathological studies revealed the toxic effects of lead on the gut of earthworms indicating severe damage in lead resistant bacteria untreated worms, whereas the cells were intact in lead resistant bacteria treated worms. COMET assay showed increased DNA damage with higher tail DNA percent in the untreated earthworms. Further, the colonisation of the bacteria supplemented, onto the gut region of earthworms was observed by scanning electron microscopy. Atomic absorption spectrophotometry indicated a fair 50% uptake of lead within the biomass of earthworm treated with lead resistant bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Electronic Commerce and Electronic Business

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    This special issue is motivated by the recent upsurge of research activity in the areas of electronic commerce and electronic business both in India and all over the world. The current ... Monte Carlo methods for pricing financial options are then.

  14. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K; Gascó, M; Klievink, A.J.; Lindgren, I; Milano, M; Panagiotopoulos, P; Pardo, T.A.; Parycek, P; Sæbø, Ø

    2016-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies.This book presents papers from the 14th International Federation for Information

  15. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information

  16. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  17. `Twisted' electrons

    Science.gov (United States)

    Larocque, Hugo; Kaminer, Ido; Grillo, Vincenzo; Leuchs, Gerd; Padgett, Miles J.; Boyd, Robert W.; Segev, Mordechai; Karimi, Ebrahim

    2018-04-01

    Electrons have played a significant role in the development of many fields of physics during the last century. The interest surrounding them mostly involved their wave-like features prescribed by the quantum theory. In particular, these features correctly predict the behaviour of electrons in various physical systems including atoms, molecules, solid-state materials, and even in free space. Ten years ago, new breakthroughs were made, arising from the new ability to bestow orbital angular momentum (OAM) to the wave function of electrons. This quantity, in conjunction with the electron's charge, results in an additional magnetic property. Owing to these features, OAM-carrying, or twisted, electrons can effectively interact with magnetic fields in unprecedented ways and have motivated materials scientists to find new methods for generating twisted electrons and measuring their OAM content. Here, we provide an overview of such techniques along with an introduction to the exciting dynamics of twisted electrons.

  18. Quantifying electron fluxes in methanogenic microbial communities

    NARCIS (Netherlands)

    Junicke, H.

    2015-01-01

    Anaerobic digestion is a widely applied process in which close interactions between different microbial groups result in the formation of renewable energy in the form of biogas. Nevertheless, the regulatory mechanisms of the electron transfer between acetogenic bacteria and methanogenic archaea in

  19. Nanotextile membranes for bacteria Escherichia coli capturing

    Directory of Open Access Journals (Sweden)

    Jaroslav Lev

    2010-01-01

    Full Text Available The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP. As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

  20. [Spectrum and susceptibility of preoperative conjunctival bacteria].

    Science.gov (United States)

    Fernández-Rubio, M E; Cuesta-Rodríguez, T; Urcelay-Segura, J L; Cortés-Valdés, C

    2013-12-01

    To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, β-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  1. Chemically enhanced sunlight for killing bacteria

    International Nuclear Information System (INIS)

    Block, S.S.; Goswami, D.Y.

    1995-01-01

    Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO 2 ) has received considerable attention. Much less recognized, however, is the ability of the same system to destroy bacteria. This study examined this phenomenon and the conditions that affect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was determined. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO 2 had no deleterious effect on the bacteria. However, several common bacteria on solar exposure in the presence of TiO 2 were killed in just a few minutes, whereas without TiO 2 it took over an hour to destroy them. A concentration of 0.01% TiO 2 was most effective in killing bacteria and 10-fold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. Alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO 2 particles suspended reduced the time necessary to kill the bacteria. Time-intensity curves for killing bacteria were the same general shape with or without TiO 2 , indicating that TiO 2 served merely as a catalyst to increase the rate of the reaction but that the mechanism of action was not changed. The shape of the curves show that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn't greatly increase the rate of kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased

  2. Using Bacteria to Store Renewable Energy (Text Version) | News | NREL

    Science.gov (United States)

    Using Bacteria to Store Renewable Energy (Text Version) Using Bacteria to Store Renewable Energy is a text version of the video entitled "Using Bacteria to Store Renewable Energy." ; Bacteria from some of the Earth's harshest environments now have a new home at NREL. [A natural spring has

  3. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  4. Advanced Electronics

    Science.gov (United States)

    2017-07-21

    AFRL-RV-PS- AFRL-RV-PS- TR-2017-0114 TR-2017-0114 ADVANCED ELECTRONICS Ashwani Sharma 21 Jul 2017 Interim Report APPROVED FOR PUBLIC RELEASE...NUMBER Advanced Electronics 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62601F 6. AUTHOR(S) 5d. PROJECT NUMBER 4846 Ashwani Sharma 5e. TASK NUMBER...Approved for public release; distribution is unlimited. (RDMX-17-14919 dtd 20 Mar 2018) 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Space Electronics

  5. Electron spectroscopy

    International Nuclear Information System (INIS)

    Hegde, M.S.

    1979-01-01

    An introduction to the various techniques in electron spectroscopy is presented. These techniques include: (1) UV Photoelectron spectroscopy, (2) X-ray Photoelectron spectroscopy, (3) Auger electron spectroscopy, (4) Electron energy loss spectroscopy, (5) Penning ionization spectroscopy and (6) Ion neutralization spectroscopy. The radiations used in each technique, the basis of the technique and the special information obtained in structure determination in atoms and molecules by each technique are summarised. (A.K.)

  6. Modulation of immune homeostasis by commensal bacteria

    Science.gov (United States)

    Ivanov, Ivaylo I.; Littman, Dan R.

    2011-01-01

    Intestinal bacteria form a resident community that has co-evolved with the mammalian host. In addition to playing important roles in digestion and harvesting energy, commensal bacteria are crucial for the proper functioning of mucosal immune defenses. Most of these functions have been attributed to the presence of large numbers of “innocuous” resident bacteria that dilute or occupy niches for intestinal pathogens or induce innate immune responses that sequester bacteria in the lumen, thus quenching excessive activation of the mucosal immune system. However it has recently become obvious that commensal bacteria are not simply beneficial bystanders, but are important modulators of intestinal immune homeostasis and that the composition of the microbiota is a major factor in pre-determining the type and robustness of mucosal immune responses. Here we review specific examples of individual members of the microbiota that modify innate and adaptive immune responses, and we focus on potential mechanisms by which such species-specific signals are generated and transmitted to the host immune system. PMID:21215684

  7. Molecular analysis of deep subsurface bacteria

    International Nuclear Information System (INIS)

    Jimenez Baez, L.E.

    1989-09-01

    Deep sediments samples from site C10a, in Appleton, and sites, P24, P28, and P29, at the Savannah River Site (SRS), near Aiken, South Carolina were studied to determine their microbial community composition, DNA homology and mol %G+C. Different geological formations with great variability in hydrogeological parameters were found across the depth profile. Phenotypic identification of deep subsurface bacteria underestimated the bacterial diversity at the three SRS sites, since bacteria with the same phenotype have different DNA composition and less than 70% DNA homology. Total DNA hybridization and mol %G+C analysis of deep sediment bacterial isolates suggested that each formation is comprised of different microbial communities. Depositional environment was more important than site and geological formation on the DNA relatedness between deep subsurface bacteria, since more 70% of bacteria with 20% or more of DNA homology came from the same depositional environments. Based on phenotypic and genotypic tests Pseudomonas spp. and Acinetobacter spp.-like bacteria were identified in 85 million years old sediments. This suggests that these microbial communities might have been adapted during a long period of time to the environmental conditions of the deep subsurface

  8. Overlapping riboflavin supply pathways in bacteria.

    Science.gov (United States)

    García-Angulo, Víctor Antonio

    2017-03-01

    Riboflavin derivatives are essential cofactors for a myriad of flavoproteins. In bacteria, flavins importance extends beyond their role as intracellular protein cofactors, as secreted flavins are a key metabolite in a variety of physiological processes. Bacteria obtain riboflavin through the endogenous riboflavin biosynthetic pathway (RBP) or by the use of importer proteins. Bacteria frequently encode multiple paralogs of the RBP enzymes and as for other micronutrient supply pathways, biosynthesis and uptake functions largely coexist. It is proposed that bacteria shut down biosynthesis and would rather uptake riboflavin when the vitamin is environmentally available. Recently, the overlap of riboflavin provisioning elements has gained attention and the functions of duplicated paralogs of RBP enzymes started to be addressed. Results point towards the existence of a modular structure in the bacterial riboflavin supply pathways. Such structure uses subsets of RBP genes to supply riboflavin for specific functions. Given the importance of riboflavin in intra and extracellular bacterial physiology, this complex array of riboflavin provision pathways may have developed to contend with the various riboflavin requirements. In riboflavin-prototrophic bacteria, riboflavin transporters could represent a module for riboflavin provision for particular, yet unidentified processes, rather than substituting for the RBP as usually assumed.

  9. Bacteria and plutonium in marine environments

    International Nuclear Information System (INIS)

    Carey, A.E.; Bowen, V.T.

    1978-01-01

    Microbes are important in geochemical cycling of many elements. Recent reports emphasize biogenous particulates and bacterial exometabolites as controlling oceanic distribution of plutonium. Bacteria perform oxidation/reduction reactions on metals such as mercury, nickel, lead, copper, and cadmium. Redox transformations or uptake of Pu by marine bacteria may well proceed by similar mechanisms. Profiles of water samples and sediment cores were obtained along the continental shelf off Nova Scotia and in the Gulf of St. Lawrence. Profiles of water samples, and sediment cores were obtained. Epifluorescent microscopy was used to view bacteria (from water or sediment) after concentration on membrane filters and staining with acridine orange. Radiochemical analyses measured Pu in sediments and water samples. Studies of 237 Pu uptake used a strain of Leucothrix mucor isolated from a macroalga. Enumeration shows bacteria to range 10 4 to 10 5 cells/ml in seawater or 10 7 to 10 8 cells/gram of sediment. These numbers are related to the levels and distrbution of Pu in the samples. In cultures of L. mucor amended with Pu atom concentrations approximating those present in open ocean environments, bacterial cells concentrated 237 Pu slower and to lower levels than did clay minerals, glass beads, or phytoplankton. These data further clarify the role of marine bacteria in Pu biogeochemistry

  10. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  11. COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for

  12. Immobilization of anaerobic bacteria on rubberized-coir for psychrophilic digestion of night soil.

    Science.gov (United States)

    Dhaked, Ram Kumar; Ramana, Karna Venkat; Tomar, Arvind; Waghmare, Chandrakant; Kamboj, Dev Vrat; Singh, Lokendra

    2005-08-01

    Low-ambient temperatures, biodigesters due to low-growth rate of the constituent bacterial consortium. Immobilization of anaerobic bacteria has been attempted in the biodigester operating at 10 degrees C. Various matrices were screened and evaluated for the immobilization of bacteria in digesters. Anaerobic digestion of night soil was carried out with hydraulic retention time in the range of 9-18 days. Among the tested matrices, rubberized-coir was found to be the most useful at 10 degrees C with optimum hydraulic retention time of 15 days. Optimum amount of coir was found as 25 g/L of the working volume of biodigesters. Immobilization of bacteria on the coir was observed by scanning electron microscopy and fluorescent microscopy. The study indicates that rubberized-coir can be utilized to increase biodegradation of night soil at higher organic loading. Another advantage of using this matrix is that it is renewable and easily available in comparison to other synthetic polymeric matrices.

  13. Experimental Research of Inactivation Effect of Low-Temperature Plasma on Bacteria

    International Nuclear Information System (INIS)

    Shi Xingmin; Yuan Yukang; Sun Yanzhou; Yuan Wang; Fengling, Peng; Qiu Yuchang

    2006-01-01

    The killing logarithms index in killing a vegetative form in an explosure of about 90 s and a spore in an explosure of about 120 s, by using a low-temperature plasma produced by dielectric barrier discharge (DBD), reached 5. The speed in killing the strains tested, by using a low-temperature plasma, was the highest with E. Coli, then S. Aureus and B. Subtilis var niger spore. The results of the scanning electron microscope showed that the low-temperature plasma destroyed the outer structure of the bacteria and that the vegetative form was more susceptible to the inactivation effect of the low-temperature plasma than was the spore. This indicated that the effects of the high voltage and high velocity particle flow, in plasma, penetrating through the outer structure of the bacteria might play a dominant role during the inactivation of the bacteria

  14. Anaerobic degradation of naphthalene by the mixed bacteria under nitrate reducing conditions

    International Nuclear Information System (INIS)

    Dou Junfeng; Liu Xiang; Ding Aizhong

    2009-01-01

    Mixed bacteria were enriched from soil samples contaminated with polycyclic aromatic hydrocarbons (PAHs). The anaerobic degradation characteristics by the enriched bacteria with different initial naphthalene concentrations were investigated under nitrate reducing conditions. The results showed that the mixed bacteria could degrade nearly all the naphthalene over the incubations of 25 days when the initial naphthalene concentration was below 30 mg/L. The degradation rates of naphthalene increased with increasing initial concentrations. A high naphthalene concentration of 30 mg/L did not inhibit neither on the bacterial growth nor on the naphthalene degradation ability. The accumulation of nitrite was occurred during the reduction of nitrate, and a nitrite concentration of 50 mg/L had no inhibition effect on the degradation of naphthalene. The calculation of electron balances revealed that most of the naphthalene was oxidized whereas a small proportion was used for cell synthesis.

  15. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  16. Electronics Industry

    National Research Council Canada - National Science Library

    Bell, Robert; Carroll-Garrison, Martina; Donovan, Daniel; Fisher, John; Guemmer, Paul; Harms, Robert; Kelly, Timothy; Love, Mattie; McReynolds, James; Ward, Ralph

    2006-01-01

    .... Government action to preserve strategic access to semiconductor producers is clearly needed to ensure DoD electronic systems can be built without compromising sensitive technology, though every...

  17. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  18. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

  19. Cell lysis and superoxide dismutase activities of highly radioresistant bacteria

    International Nuclear Information System (INIS)

    Yoshinaka, Taeko; Yano, Keiji; Yamaguchi, Hikoyuki

    1976-01-01

    The highly radioresistant bacterium, Arthrobacter radiotolerans, has been isolated from the radioactive hot spring of Misasa, and it does not sporulate, it is Gram-positive, and its color is pink to red. This bacterium shows the highest resistance to gamma-ray among Gram-positive resistants, but the lytic enzyme capable of lysing the cells of strong radioresistants and the surface structure of the cells are little known except those about Micrococcus radiodurans. The cells of the M. radiodurans can be lysed by Achramobacter lyticus enzyme, and electron microscopic observation and chemical analysis revealed the mutilayered surface structure of the cells consisting of an inner membrane, a mucopeptide wall layer and a very outer layer. The superoxide dismutase (SOD) activity of aerobic and anaerobic bacteria was studied, and the relatively high SOD activity of the M. radiodurans was found. The SOD function acts against the threat posed by the reactive superoxide radical being generated biologically, photochemically and radiochemically in the presence of molecular oxygen. In this paper, it is reported that the lytic enzyme No.2 obtained from Cytophaga sp., containing N-acetyl-muramyl-L-alanine amidase, peptidase and endopeptidase, and showing broad lytic spectra, was able to lyse the cells of A. radiotolerans and four radioresistant micrococci, and the radioresistant bacteria showed relatively high SOD activity except M. sp. 248. It is well known that superoxide anions are generated by aerobic irradiation, and are toxic to microbial cells. (Kako, I.)

  20. Cell lysis and superoxide dismutase activities of highly radioresistant bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaka, T; Yano, K; Yamaguchi, H [Tokyo Univ. (Japan). Faculty of Agriculture

    1976-01-01

    The highly radioresistant bacterium, Arthrobacter radiotolerans, has been isolated from the radioactive hot spring of Misasa, and it does not sporulate, it is Gram-positive, and its color is pink to red. This bacterium shows the highest resistance to gamma-ray among Gram-positive resistants, but the lytic enzyme capable of lysing the cells of strong radioresistants and the surface structure of the cells are little known except those about Micrococcus radiodurans. The cells of the M. radiodurans can be lysed by Achramobacter lyticus enzyme, and electron microscopic observation and chemical analysis revealed the mutilayered surface structure of the cells consisting of an inner membrane, a mucopeptide wall layer and a very outer layer. The superoxide dismutase (SOD) activity of aerobic and anaerobic bacteria was studied, and the relatively high SOD activity of the M. radiodurans was found. The SOD function acts against the threat posed by the reactive superoxide radical being generated biologically, photochemically and radiochemically in the presence of molecular oxygen. In this paper, it is reported that the lytic enzyme No.2 obtained from Cytophaga sp., containing N-acetyl-muramyl-L-alanine amidase, peptidase and endopeptidase, and showing broad lytic spectra, was able to lyse the cells of A. radiotolerans and four radioresistant micrococci, and the radioresistant bacteria showedrelatively high SOD activity except M. sp. 248. It is well known that superoxide anions are generated by aerobic irradiation, and are toxic to microbial cells.