WorldWideScience

Sample records for extremely acidophilic bacterium

  1. Size-Controlled Production of Gold Bionanoparticles Using the Extremely Acidophilic Fe(III-Reducing Bacterium, Acidocella aromatica

    Directory of Open Access Journals (Sweden)

    Intan Nurul Rizki

    2018-02-01

    Full Text Available Recycling of gold-bearing “urban mine” resources, such as waste printed circuit boards (PCBs, is attracting an increasing interest. Some of the gold leaching techniques utilize acidic lixiviants and in order to eventually target such acidic leachates, the utility of the acidophilic Fe(III-reducing heterotrophic bacterium, Acidocella (Ac. aromatica PFBC was evaluated for production of Au(0 bionanoparticles (bio-AuNPs. Au(III ions (as AuCl4−, initially 10 mg/L, were readily adsorbed onto the slightly-positively charged Ac. aromatica cell surface and transported into cytoplasm to successfully form intracellular bio-AuNPs in a simple one-step microbiological reaction. Generally, increasing the initial concentration of formate as e-donor corresponded to faster Au(III bioreduction and a greater number of Au(0 nucleation sites with less crystal growth within 40–60 h: i.e., use of 1, 5, 10, or 20 mM formate led to production of bio-AuNPs of 48, 24, 13, or 12 nm in mean particle size with 2.3, 17, 62, and 97 particles/cell, respectively. Addition of Cu2+ as an enzymatic inhibitor significantly decreased the number of Au(0 nucleation sites but enhanced crystal growth of individual particles. As a result, the manipulation of the e-donor concentration combined with an enzyme inhibitor enabled the 3-grade size-control of bio-AuNPs (nearly within a normal distribution at 48, 26 or 13 nm by use of 1 mM formate, 20 mM formate (+Cu2+ or 10 mM formate, respectively, from highly acidic, dilute Au(III solutions.

  2. Thiol/Disulfide system plays a crucial role in redox protection in the acidophilic iron-oxidizing bacterium Leptospirillum ferriphilum.

    Directory of Open Access Journals (Sweden)

    Javiera Norambuena

    Full Text Available Thiol/disulfide systems are involved in the maintenance of the redox status of proteins and other molecules that contain thiol/disulfide groups. Leptospirillum ferriphilum DSM14647, an acidophilic bacterium that uses Fe(2+ as electron donor, and withstands very high concentrations of iron and other redox active metals, is a good model to study how acidophiles preserve the thiol/disulfide balance. We studied the composition of thiol/disulfide systems and their role in the oxidative stress response in this extremophile bacterium. Bioinformatic analysis using genomic data and enzymatic assays using protein extracts from cells grown under oxidative stress revealed that the major thiol/disulfide system from L. ferriphilum are a cytoplasmic thioredoxin system (composed by thioredoxins Trx and thioredoxin reductase TR, periplasmic thiol oxidation system (DsbA/DsbB and a c-type cytochrome maturation system (DsbD/DsbE. Upon exposure of L. ferriphilum to reactive oxygen species (ROS-generating compounds, transcriptional activation of the genes encoding Trxs and the TR enzyme, which results in an increase of the corresponding activity, was observed. Altogether these data suggest that the thioredoxin-based thiol/disulfide system plays an important role in redox protection of L. ferriphilum favoring the survival of this microorganism under extreme environmental oxidative conditions.

  3. Sorption of ferrous iron by EPS from the acidophilic bacterium Acidiphilium Sp.: A mechanism proposal

    Energy Technology Data Exchange (ETDEWEB)

    Tapia, J.M.; MuNoz, J.; Gonzlez, F.; Blazquez, M.L.; Ballester, A.

    2016-07-01

    The aim of this work was to assess the uptake of Fe(II) by extracellular polymeric substances (EPS) from the acidophilic bacterium Acidiphillium 3.2Sup(5). These EPS were extracted using EDTA. EPS of A. 3.2Sup(5) loaded in sorption tests with Fe(II), were characterized using the following experimental techniques: scanning electron microscopy (SEM) with energy dispersive X-ray microanalysis (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental results indicate that EPS adsorb ferrous iron according to Freundlich model with a metal sorption uptake of K = 1.14 mg1−1/n L1/n g−1 and a sorption intensity of 1/n = 1.26. In addition, ferrous iron sorption by EPS took place by preferential interaction with the carboxyl group which promotes the formation of ferrous iron oxalates (FeC2O4). Since the interaction reaction was reversible (Log K = 0.77 ± 0.33), that means that the cation sorption can be reversed at convenience. (Author)

  4. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

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

  5. Methylocapsa acidiphila gen. nov., sp. nov., a novel methane-oxidizing and dinitrogen-fixing acidophilic bacterium from Sphagnum bog.

    Science.gov (United States)

    Dedysh, Svetlana N; Khmelenina, Valentina N; Suzina, Natalia E; Trotsenko, Yuri A; Semrau, Jeremy D; Liesack, Werner; Tiedje, James M

    2002-01-01

    A novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov., are proposed for a methane-oxidizing bacterium isolated from an acidic Sphagnum peat bog. This bacterium, designated strain B2T, represents aerobic, gram-negative, colourless, non-motile, curved coccoids that form conglomerates covered by an extracellular polysaccharide matrix. The cells use methane and methanol as sole sources of carbon and energy and utilize the serine pathway for carbon assimilation. Strain B2T is a moderately acidophilic organism with growth between pH 4.2 and 7.2 and at temperatures from 10 to 30 degrees C. The cells possess a well-developed system of intracytoplasmic membranes (ICM) packed in parallel on only one side of the cell membrane. This type of ICM structure represents a novel arrangement, which was termed type III. The resting cells are Azotobacter-type cysts. Strain B2T is capable of atmospheric nitrogen fixation; it possesses particulate methane monooxygenase and does not express soluble methane monooxygenase. The major phospholipid fatty acid is 18:1omega7c and the major phospholipids are phosphatidylglycerols. The G+C content of the DNA is 63.1 mol%. This bacterium belongs to the alpha-subclass of the Proteobacteria and is most closely related to the acidophilic methanotroph Methylocella palustris KT (97.3% 16S rDNA sequence similarity). However, the DNA-DNA hybridization value between strain B2T and Methylocella palustris K(T) is only 7%. Thus, strain B2T is proposed to comprise a novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov. Strain B2T (= DSM 13967T = NCIMB 13765T) is the type strain.

  6. Gene loss and horizontal gene transfer contributed to the genome evolution of the extreme acidophile Ferrovum

    Directory of Open Access Journals (Sweden)

    Sophie Roxana Ullrich

    2016-05-01

    Full Text Available Acid mine drainage (AMD, associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus Ferrovum are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of Ferrovum has proven to be extremely difficult and has so far only been successful for the designated type strain Ferrovum myxofaciens P3G. In this study, the genomes of two novel strains of Ferrovum (PN-J185 and Z-31 derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of Ferrovum sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G. Phylogenomic scrutiny suggests that the four strains represent three Ferrovum species that cluster in two groups (1 and 2. Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the F. myxofaciens strains (group 1 appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features contributed to the observed

  7. Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

    Directory of Open Access Journals (Sweden)

    Stott Matthew B

    2008-07-01

    Full Text Available Abstract Background The phylum Verrucomicrobia is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the Verrucomicrobia, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia. Results We report the complete genome sequence of strain V4, the first one from a representative of the Verrucomicrobia. Isolate V4, initially named "Methylokorus infernorum" (and recently renamed Methylacidiphilum infernorum is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of M. infernorum was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C1-utilization pathways compared to other known methylotrophs. The M. infernorum genome does not encode tubulin, which was previously discovered in bacteria of the genus Prosthecobacter, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping Planctomycetes, Verrucomicrobia and Chlamydiae into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the M. infernorum lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of M. infernorum shows apparent adaptations for existence under extremely

  8. Extreme Ionizing-Radiation-Resistant Bacterium

    Science.gov (United States)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

  9. A Lux-like Quorum Sensing System in the Extreme Acidophile Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    MARIELLA RIVAS

    2005-01-01

    Full Text Available The genome of the acidophilic, proteobacterium Acidithiobacillus ferrooxidans, contains linked but divergently oriented genes, termed afeI and afeR, whose predicted protein products are significantly similar to the LuxI and LuxR families of proteins. A possible promoter and Lux box are predicted upstream of afeI. A cloned copy of afeI, expressed in E. coli, encodes an enzyme that catalyzes the production of a diffusible compound identified by gas chromatography and mass spectrometry as an unsubstituted N-acyl homoserine lactone (AHL of chain length C14. This AHL can be detected by a reporter strain of Sinorhizobium meliloti Rm41 suggesting that it is biologically active. The reporter strain also responds to extracts of the supernatant of A. ferrooxidans grown to early stationary phase in sulfur medium indicating that a diffusible AHL is produced by this microorganism. Semi-quantitative RT-PCR experiments indicate that afeI and afeR are expressed maximally in early stationary phase and are more expressed when A. ferrooxidans is grown in sulfur- rather than iron-containing medium. Given the predicted amino acid sequence and functional properties of AfeI and AfeR it is proposed that A. ferrooxidans has a quorum sensing system similar to the LuxI-LuxR paradigm.

  10. Methylocella palustris gen. nov., sp. nov., a new methane-oxidizing acidophilic bacterium from peat bogs, representing a novel subtype of serine-pathway methanotrophs.

    Science.gov (United States)

    Dedysh, S N; Liesack, W; Khmelenina, V N; Suzina, N E; Trotsenko, Y A; Semrau, J D; Bares, A M; Panikov, N S; Tiedje, J M

    2000-05-01

    A new genus, Methylocella, and a new species, Methylocella palustris, are proposed for three strains of methane-oxidizing bacteria isolated from acidic Sphagnum peat bogs. These bacteria are aerobic, Gram-negative, colourless, non-motile, straight and curved rods that utilize the serine pathway for carbon assimilation, multiply by normal cell division and contain intracellular poly-beta-hydroxybutyrate granules (one at each pole). These strains use methane and methanol as sole sources of carbon and energy and are moderately acidophilic organisms with growth between pH 4.5 and pH 7.0, the optimum being at pH 5.0-5.5. The temperature range for growth is 10-28 degrees C with the optimum at 15-20 degrees C. The intracytoplasmic membrane system is different from those of type I and II methanotrophs. Cells contain an extensive periplasmic space and a vesicular membrane system connected to the cytoplasmic membrane. The strains grew only on media with a low salt content (0.2-0.5 g l(-1)). All three strains were found to possess soluble methane monooxygenase and are able to fix atmospheric nitrogen via an oxygen-sensitive nitrogenase. No products were observed in a PCR with particulate methane monooxygenase-targeted primers; hybridization with a pmoA probe was also negative. The major phospholipid fatty acids are 18:1 acids. The G+C content of the DNA is 61.2 mol%. The three strains share identical 16S rRNA gene sequences and represent a novel lineage of methane-oxidizing bacteria within the alpha-subclass of the class Proteobacteria and are only moderately related to type II methanotrophs of the Methylocystis-Methylosinus group. The three strains are most closely related to the acidophilic heterotrophic bacterium Beijerinckia indica subsp. indica (96.5% 16S rDNA sequence similarity). Collectively, these strains comprise a new species and genus Methylocella palustris gen. nov., sp. nov.; strain KT (= ATCC 700799T) is the type strain.

  11. Methyloferula stellata gen. nov., sp. nov., an acidophilic, obligately methanotrophic bacterium that possesses only a soluble methane monooxygenase.

    Science.gov (United States)

    Vorobev, Alexey V; Baani, Mohamed; Doronina, Nina V; Brady, Allyson L; Liesack, Werner; Dunfield, Peter F; Dedysh, Svetlana N

    2011-10-01

    Two strains of aerobic methanotrophic bacteria, AR4(T) and SOP9, were isolated from acidic (pH 3.8-4.0) Sphagnum peat bogs in Russia. Another phenotypically similar isolate, strain LAY, was obtained from an acidic (pH 4.0) forest soil in Germany. Cells of these strains were Gram-negative, non-pigmented, non-motile, thin rods that multiplied by irregular cell division and formed rosettes or amorphous cell conglomerates. Similar to Methylocella species, strains AR4(T), SOP9 and LAY possessed only a soluble form of methane monooxygenase (sMMO) and lacked intracytoplasmic membranes. Growth occurred only on methane and methanol; the latter was the preferred growth substrate. mRNA transcripts of sMMO were detectable in cells when either methane or both methane and methanol were available. Carbon was assimilated via the serine and ribulose-bisphosphate (RuBP) pathways; nitrogen was fixed via an oxygen-sensitive nitrogenase. Strains AR4(T), SOP9 and LAY were moderately acidophilic, mesophilic organisms capable of growth between pH 3.5 and 7.2 (optimum pH 4.8-5.2) and at 4-33 °C (optimum 20-23 °C). The major cellular fatty acid was 18 : 1ω7c and the quinone was Q-10. The DNA G+C content was 55.6-57.5 mol%. The isolates belonged to the family Beijerinckiaceae of the class Alphaproteobacteria and were most closely related to the sMMO-possessing methanotrophs of the genus Methylocella (96.4-97.0 % 16S rRNA gene sequence similarity), particulate MMO (pMMO)-possessing methanotrophs of the genus Methylocapsa (96.1-97.0 %), facultative methylotrophs of the genus Methylovirgula (96.1-96.3 %) and non-methanotrophic organotrophs of the genus Beijerinckia (96.5-97.0 %). Phenotypically, strains AR4(T), SOP9 and LAY were most similar to Methylocella species, but differed from members of this genus by cell morphology, greater tolerance of low pH, detectable activities of RuBP pathway enzymes and inability to grow on multicarbon compounds. Therefore, we propose a novel

  12. Cobalamin Protection against Oxidative Stress in the Acidophilic Iron-oxidizing Bacterium Leptospirillum group II CF-1

    Directory of Open Access Journals (Sweden)

    Gloria Paz Levicán

    2016-05-01

    Full Text Available Members of the genus Leptospirillum are aerobic iron-oxidizing bacteria belonging to the phylum Nitrospira. They are important members of microbial communities that catalyze the biomining of sulfidic ores, thereby solubilizing metal ions. These microorganisms live under extremely acidic and metal-loaded environments and thus must tolerate high concentrations of reactive oxygen species. Cobalamin (vitamin B12 is a cobalt-containing tetrapyrrole cofactor involved in intramolecular rearrangement reactions and has recently been suggested to be an intracellular antioxidant. In this work, we investigated the effect of the exogenous addition of cobalamin on oxidative stress parameters in Leptospirillum group II strain CF-1. Our results revealed that the external supplementation of cobalamin reduces the levels of intracellular reactive oxygen species and the damage to biomolecules, and also stimulates the growth and survival of cells exposed to oxidative stress exerted by ferric ion, hydrogen peroxide, chromate and diamide. Furthermore, exposure of strain CF-1 to oxidative stress elicitors resulted in the transcriptional activation of the cbiA gene encoding CbiA of the cobalamin biosynthetic pathway. Altogether, these data suggest that cobalamin plays an important role in redox protection of Leptospirillum strain CF-1, supporting survival of this microorganism under extremely oxidative environmental conditions. Understanding the mechanisms underlying the protective effect of cobalamin against oxidative stress may help to develop strategies to make biomining processes more effective.

  13. Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær

    1995-01-01

    An anaerobic, extremely thermophilic, cellulolytic, non-spore-forming bacterium, strain 6A, was isolated from an alkaline hot spring in Hverageroi, Iceland. The bacterium was non-motile, rod-shaped (1.5-3.5 x 0.7 mu m) and occurred singly, in pairs or in chains and stained gram-negative. The growth...

  14. Carbohydrate utilization patterns for the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus reveal broad growth substrate preferences

    NARCIS (Netherlands)

    Vanfossen, A.L.; Verhaart, M.R.A.; Kengen, S.W.M.; Kelly, R.M.

    2009-01-01

    Co-utilization of hexoses and pentoses derived from lignocellulose is an attractive trait in microorganisms considered for consolidated biomass processing to biofuels. This issue was examined for the H2-producing, extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus growing on

  15. Complete genome sequence of the bioleaching bacterium Leptospirillum sp. group II strain CF-1.

    Science.gov (United States)

    Ferrer, Alonso; Bunk, Boyke; Spröer, Cathrin; Biedendieck, Rebekka; Valdés, Natalia; Jahn, Martina; Jahn, Dieter; Orellana, Omar; Levicán, Gloria

    2016-03-20

    We describe the complete genome sequence of Leptospirillum sp. group II strain CF-1, an acidophilic bioleaching bacterium isolated from an acid mine drainage (AMD). This work provides data to gain insights about adaptive response of Leptospirillum spp. to the extreme conditions of bioleaching environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Astrobiological significance of chemolithoautotrophic acidophiles

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2004-02-01

    For more than a century (since Winogradsky discovered lithautotrophic bacteria) there has been a dilemma in microbiology about life that first inhabited the Earth. Which types of life forms first appeared in the primordial oceans during the earliest geological period on Earth as the primary ancestors of modern biological diversity? How did a metabolism of ancestors evolve: from lithoautotrophic to lithoheterotrophic and organoheterotrophic or from organoheterotrophic to organautotrophic and lithomixotrophic types? At the present time, it is known that chemolithoheterotrophic and chemolithoautotrophic metabolizing bacteria are wide spread in different ecosystems. On Earth the acidic ecosystems are associated with geysers, volcanic fumaroles, hot springs, deep sea hydrothermal vents, caves, acid mine drainage and other technogenic ecosystems. Bioleaching played a significant roel on a global geological scale during the Earth's formation. This important feature of bacteria has been successfully applied in industry. The lithoautotrophs include Bacteria and Archaea belonging to diverse genera containing thermophilic and mesophilic species. In this paper we discuss the lithotrophic microbial acidophiles and present some data with a description of new acidophilic iron- and sulfur-oxidizing bacterium isolated from the Chena Hot Springs in Alaska. We also consider the possible relevance of microbial acidophiles to Venus, Io, and acidic inclusions in glaciers and icy moons.

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

    Directory of Open Access Journals (Sweden)

    Peng Chen

    Full Text Available Abstract Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese. It contains over 90% tetra-arsenic tetrasulfide (As4S4. Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans. Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for realgar preparation. The present systematic review reports on the research progress in realgar bioleaching and its antitumor mechanism as an anticancer agent. A total of 93 research articles that report on the biological activity of extracts from realgar using bacteria and its preparation were presented in this review. The realgar bioleaching solution (RBS works by inducing apoptosis when it is used to treat tumor cells in vitro and in vivo. When it is used to treat animal model organisms in vivo, such as mice and Caenorhabditis elegans, tumor tissues grew more slowly, with mass necrosis. Meanwhile, the agent also showed obvious inhibition of tumor cell growth. Bioleaching technology greatly improves the utilization of realgar and is a novel methodology to improve the traditional method.

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

    Science.gov (United States)

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

    2017-05-22

    Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese). It contains over 90% tetra-arsenic tetra-sulfide (As 4 S 4 ). Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans). Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for realgar preparation. The present systematic review reports on the research progress in realgar bioleaching and its antitumor mechanism as an anticancer agent. A total of 93 research articles that report on the biological activity of extracts from realgar using bacteria and its preparation were presented in this review. The realgar bioleaching solution (RBS) works by inducing apoptosis when it is used to treat tumor cells in vitro and in vivo. When it is used to treat animal model organisms in vivo, such as mice and Caenorhabditis elegans, tumor tissues grew more slowly, with mass necrosis. Meanwhile, the agent also showed obvious inhibition of tumor cell growth. Bioleaching technology greatly improves the utilization of realgar and is a novel methodology to improve the traditional method.

  19. Hydrogenomics of the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Werken, van de H.J.G.; Verhaart, M.R.A.; Vanfossen, A.L.; Willquist, K.; Lewis, D.L.; Nichols, J.D.; Goorissen, H.P.; Mongodin, E.F.; Nelson, K.E.; Niel, van E.W.J.; Stams, A.J.M.; Ward, D.E.; Vos, de W.M.; Oost, van der J.; Kelly, R.M.; Kengen, S.W.M.

    2008-01-01

    Caldicellulosiruptor saccharolyticus is an extremely thermophilic, gram-positive anaerobe which ferments cellulose-, hemicellulose- and pectin-containing biomass to acetate, CO(2), and hydrogen. Its broad substrate range, high hydrogen-producing capacity, and ability to coutilize glucose and xylose

  20. Extreme furfural tolerance of a soil bacterium Enterobacter cloacae GGT036.

    Science.gov (United States)

    Choi, Sun Young; Gong, Gyeongtaek; Park, Hong-Sil; Um, Youngsoon; Sim, Sang Jun; Woo, Han Min

    2015-01-10

    Detoxification process of cellular inhibitors including furfural is essential for production of bio-based chemicals from lignocellulosic biomass. Here we isolated an extreme furfural-tolerant bacterium Enterobacter cloacae GGT036 from soil sample collected in Mt. Gwanak, Republic of Korea. Among isolated bacteria, only E. cloacae GGT036 showed cell growth with 35 mM furfural under aerobic culture. Compared to the maximal half inhibitory concentration (IC50) of well-known industrial strains Escherichia coli (24.9 mM furfural) and Corynebacterium glutamicum (10 mM furfural) based on the cell density, IC50 of E. cloacae GGT036 (47.7 mM) was significantly higher after 24 h, compared to E. coli and C. glutamicum. Since bacterial cell growth was exponentially inhibited depending on linearly increased furfural concentrations in the medium, we concluded that E. cloacae GGT036 is an extreme furfural-tolerant bacterium. Recently, the complete genome sequence of E. cloacae GGT036 was announced and this could provide an insight for engineering of E. cloacae GGT036 itself or other industrially relevant bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Pyrosequencing reveals correlations between extremely acidophilic bacterial communities with hydrogen sulphide concentrations, pH and inert polymer coatings at concrete sewer crown surfaces.

    Science.gov (United States)

    Pagaling, E; Yang, K; Yan, T

    2014-07-01

    To investigate the acidophilic bacterial communities involved in microbially induced concrete corrosion (MICC). Our study sites located downstream from a forced main provided a unique opportunity to study the microbial communities involved in MICC under different environmental conditions (gradients of atmospheric H(2)S, sulphate concentration and pH) and under pipe modifications (coated vs uncoated). Bacterial cell density estimated by both cultivation- and DNA-based methods was low in the corroded sewer samples. Pyrosequencing and cloning showed that Mycobacterium and Acidithiobacillus dominated the acidophilic microbial communities. Methylacidiphilum was also dominant in samples where methane was detected. Correlation analysis indicated that Mycobacterium and Acidithiobacillus were significantly affected by pH and that Mycobacterium could better withstand highly acidic conditions compared to Acidithiobacillus. Communities dominated by Mycobacterium favoured conditions in the lined sewer pipes, while communities with a higher relative abundance of Acidithiobacillus favoured the unlined sewer pipes. Identifying the key micro-organisms involved in MICC and knowing how they interact with their environment are essential aspects for identifying steps towards concrete corrosion management. © 2014 The Society for Applied Microbiology.

  2. Purification and characterization of an extreme halothermophilic protease from a halophilic bacterium Chromohalobacter sp. TVSP101

    Directory of Open Access Journals (Sweden)

    Malashetty Vidyasagar

    2009-03-01

    Full Text Available An extreme halophilic bacterium was isolated from solar saltern samples and identified based on biochemical tests and 16S r RNA sequencing as Chromohalobacter sp. strain TVSP101. The halophilic protease was purified using ultrafiltration, ethanol precipitation, hydrophobic interaction column chromatography and gel permeation chromatography to 180 fold with 22% yield. The molecular mass of the protease determined by SDS PAGE was 66 kDa. The purified enzyme was salt dependent for its activity and stability with an optimum of 4.5 M NaCl. The optimum temperature for maximum protease activity was 75°C. The protease was optimally active at pH 8 and retained more than 80% of its activity in the range of pH 7-10. Sucrose and glycine at 10% (w/v were the most effective osmolytes, retained 100% activity in the absence of NaCl. The activity was completely inhibited by ZnCl2 (2 mM, 0.1% SDS and PMSF (1mM. The enzyme was not inhibited by 1mM of pepstatin, EDTA and PCMB. The protease was active and retained 100% it activity in 10% (v/v DMSO, DMF, ethanol and acetone.

  3. Insight into glycoside hydrolases for debranched xylan degradation from extremely thermophilic bacterium Caldicellulosiruptor lactoaceticus.

    Directory of Open Access Journals (Sweden)

    Xiaojing Jia

    Full Text Available Caldicellulosiruptor lactoaceticus 6A, an anaerobic and extremely thermophilic bacterium, uses natural xylan as carbon source. The encoded genes of C. lactoaceticus 6A for glycoside hydrolase (GH provide a platform for xylan degradation. The GH family 10 xylanase (Xyn10A and GH67 α-glucuronidase (Agu67A from C. lactoaceticus 6A were heterologously expressed, purified and characterized. Both Xyn10A and Agu67A are predicted as intracellular enzymes as no signal peptides identified. Xyn10A and Agu67A had molecular weight of 47.0 kDa and 80.0 kDa respectively as determined by SDS-PAGE, while both appeared as homodimer when analyzed by gel filtration. Xyn10A displayed the highest activity at 80 °C and pH 6.5, as 75 °C and pH 6.5 for Agu67A. Xyn10A had good stability at 75 °C, 80 °C, and pH 4.5-8.5, respectively, and was sensitive to various metal ions and reagents. Xyn10A possessed hydrolytic activity towards xylo-oligosaccharides (XOs and beechwood xylan. At optimum conditions, the specific activity of Xyn10A was 44.6 IU/mg with beechwood xylan as substrate, and liberated branched XOs, xylobiose, and xylose. Agu67A was active on branched XOs with methyl-glucuronic acids (MeGlcA sub-chains, and primarily generated XOs equivalents and MeGlcA. The specific activity of Agu67A was 1.3 IU/mg with aldobiouronic acid as substrate. The synergistic action of Xyn10A and Agu67A was observed with MeGlcA branched XOs and xylan as substrates, both backbone and branched chain of substrates were degraded, and liberated xylose, xylobiose, and MeGlcA. The synergism of Xyn10A and Agu67A provided not only a thermophilic method for natural xylan degradation, but also insight into the mechanisms for xylan utilization of C. lactoaceticus.

  4. Biosynthesis of gold nanoparticles by the extreme bacterium Deinococcus radiodurans and an evaluation of their antibacterial properties.

    Science.gov (United States)

    Li, Jiulong; Li, Qinghao; Ma, Xiaoqiong; Tian, Bing; Li, Tao; Yu, Jiangliu; Dai, Shang; Weng, Yulan; Hua, Yuejin

    Deinococcus radiodurans is an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability of D. radiodurans to reduce Au(III) and biosynthesize gold nanoparticles (AuNPs) was investigated in aqueous solution by ultraviolet and visible (UV/Vis) absorption spectroscopy, electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). D. radiodurans efficiently synthesized AuNPs from 1 mM Au(III) solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III) may be reduced to Au(I), and further reduced to Au(0) with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative ( Escherichia coli ) and Gram-positive ( Staphylococcus aureus ) bacteria by damaging their cytoplasmic membrane. Therefore, the extreme bacterium D. radiodurans can be used as a novel bacterial candidate for efficient biosynthesis of AuNPs, which exhibited potential in biomedical application as an antibacterial agent.

  5. Effect of xylose and nutrients concentration on ethanol production by a newly isolated extreme thermophilic bacterium

    DEFF Research Database (Denmark)

    Tomás, Ana Faria; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2011-01-01

    An extreme thermophilic ethanol-producing strain was isolated from an ethanol high-yielding mixed culture, originally isolated from a hydrogen producing reactor operated at 70 °C. Ethanol yields were assessed with increasing concentrations of xylose, up to 20 g/l. The ability of the strain to gro...... product under most of the conditions tested, including in media lacking vitamins, peptone and yeast extract. The results indicate that this new organism is a promising candidate for the development of a second generation bio-ethanol production process. © IWA Publishing 2011....

  6. Biosynthesis of gold nanoparticles by the extreme bacterium Deinococcus radiodurans and an evaluation of their antibacterial properties

    Directory of Open Access Journals (Sweden)

    Li J

    2016-11-01

    Full Text Available Jiulong Li,1,* Qinghao Li,1,* Xiaoqiong Ma,2,* Bing Tian,1 Tao Li,1 Jiangliu Yu,1 Shang Dai,1 Yulan Weng,1 Yuejin Hua1 1Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, 2Central Laboratory, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China *These authors contributed equally to this work Abstract: Deinococcus radiodurans is an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability of D. radiodurans to reduce Au(III and biosynthesize gold nanoparticles (AuNPs was investigated in aqueous solution by ultraviolet and visible (UV/Vis absorption spectroscopy, electron microscopy, X-ray diffraction (XRD, dynamic light scattering (DLS, Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS. D. radiodurans efficiently synthesized AuNPs from 1 mM Au(III solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III may be reduced to Au(I, and further reduced to Au(0 with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative (Escherichia coli and Gram-positive (Staphylococcus aureus bacteria by damaging their cytoplasmic membrane. Therefore, the extreme

  7. The common vaginal commensal bacterium Ureaplasma parvum is associated with chorioamnionitis in extreme preterm labor.

    Science.gov (United States)

    Cox, Ciara; Saxena, Nita; Watt, Alison P; Gannon, Caroline; McKenna, James P; Fairley, Derek J; Sweet, David; Shields, Michael D; L Cosby, Sara; Coyle, Peter V

    2016-11-01

    To assess the association of vaginal commensal and low-grade pathogenic bacteria including Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium, Group B streptococcus (GBS), and Gardnerella vaginalis, in women who delivered preterm at less than 37-week gestation in the presence or absence of inflammation of the chorioamnionitic membranes. A case control study involving women who delivered before 37-week gestation with and without inflammation of chorioamnionitic membranes. A total of 57 placental samples were histologically examined for polymorphonuclear leukocyte infiltration of placental tissue for evidence of chorioamnionitis, and by type-specific nucleic acid amplification for evidence of infection with one or more of the target bacteria. Demographic data were collected for each mother. Among the 57 placental samples, 42.1% had chorioamnionitis and 24.6% delivered in the second trimester of pregnancy; U. parvum, U. urealyticum, G. vaginalis, and GBS were all detected in the study with respective prevalence of 19.3%, 3.5%, 17.5%, and 15.8%; M. genitalium and M. hominis were not detected. U. parvum was significantly associated with chorioamnionitis (p = 0.02; OR 5.0; (95% CI 1.2-21.5) and was more common in women who delivered in the second (35.7%) compared to the third trimester of pregnancy (13.9%). None of the other bacteria were associated with chorioamnionitis or earlier delivery, and all G. vaginalis-positive women delivered in the third trimester of pregnancy (p = 0.04). The detection of U. parvum in placental tissue was significantly associated with acute chorioamnionitis in women presenting in extreme preterm labor.

  8. Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park.

    Science.gov (United States)

    Hamilton-Brehm, Scott D; Mosher, Jennifer J; Vishnivetskaya, Tatiana; Podar, Mircea; Carroll, Sue; Allman, Steve; Phelps, Tommy J; Keller, Martin; Elkins, James G

    2010-02-01

    A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47(T), was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 microm long by 0.2 microm wide and grew at temperatures between 55 and 85 degrees C, with the optimum at 78 degrees C. The pH range for growth was 6.0 to 8.0, with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rate at 0.75 h(-1). The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass, and Populus. OB47(T) was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbitol, carboxymethylcellulose, and casein. Yeast extract stimulated growth, and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation end products were mainly acetate, H2, and CO2, although lactate and ethanol were produced in 5-liter batch fermentations. The G+C content of the DNA was 35 mol%, and sequence analysis of the small subunit rRNA gene placed OB47(T) within the genus Caldicellulosiruptor. Based on its phylogenetic and phenotypic properties, the isolate is proposed to be designated Caldicellulosiruptor obsidiansis sp. nov. and OB47 is the type strain (ATCC BAA-2073).

  9. Caldicellulosiruptor obsidiansis sp. nov., an Anaerobic, Extremely Thermophilic, Cellulolytic Bacterium Isolated from Obsidian Pool, Yellowstone National Park▿

    Science.gov (United States)

    Hamilton-Brehm, Scott D.; Mosher, Jennifer J.; Vishnivetskaya, Tatiana; Podar, Mircea; Carroll, Sue; Allman, Steve; Phelps, Tommy J.; Keller, Martin; Elkins, James G.

    2010-01-01

    A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47T, was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 μm long by 0.2 μm wide and grew at temperatures between 55 and 85°C, with the optimum at 78°C. The pH range for growth was 6.0 to 8.0, with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rate at 0.75 h−1. The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass, and Populus. OB47T was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbitol, carboxymethylcellulose, and casein. Yeast extract stimulated growth, and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation end products were mainly acetate, H2, and CO2, although lactate and ethanol were produced in 5-liter batch fermentations. The G+C content of the DNA was 35 mol%, and sequence analysis of the small subunit rRNA gene placed OB47T within the genus Caldicellulosiruptor. Based on its phylogenetic and phenotypic properties, the isolate is proposed to be designated Caldicellulosiruptor obsidiansis sp. nov. and OB47 is the type strain (ATCC BAA-2073). PMID:20023107

  10. Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California

    Science.gov (United States)

    Blum, Jodi Switzer; Kulp, Thomas R.; Han, Sukkyun; Lanoil, Brian; Saltikov, Chad W.; Stolz, John F.; Miller, Laurence G.; Oremland, Ronald S.

    2012-01-01

    A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125–330 g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50–330 g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.

  11. Production of thermophilic and acidophilic endoglucanases by ...

    African Journals Online (AJOL)

    Production of thermophilic and acidophilic endoglucanases by mutant Trichoderma atroviride 102C1 using agro-industrial by-products. ... The effect of the carbon (sugarcane bagasse: SCB) and nitrogen (corn steep liquor: CSL) sources on ...

  12. A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

    Science.gov (United States)

    Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

    2017-11-01

    Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Sulfobacillus benefaciens sp. nov., an acidophilic facultative anaerobic Firmicute isolated from mineral bioleaching operations.

    Science.gov (United States)

    Johnson, D Barrie; Joulian, Catherine; d'Hugues, Patrick; Hallberg, Kevin B

    2008-11-01

    Gram-positive bacteria found as the sole Firmicutes present in two mineral bioleaching stirred tanks, and a third bacterium isolated from a heap leaching operation, were shown to be closely related to each other but distinct from characterized acidophilic iron- and sulfur-oxidizing bacteria of the genus Sulfobacillus, to which they were affiliated. One of the isolates (BRGM2) was shown to be a thermo-tolerant (temperature optimum 38.5 degrees C, and maximum 47 degrees C) obligate acidophile (pH optimum 1.5, and minimum 0.8), and also noted to be a facultative anaerobe, growing via ferric iron respiration in the absence of oxygen. Although isolates BRGM2 and TVK8 were able to metabolize many monomeric organic substrates, their propensity for autotrophic growth was found to be greater than that of Sulfobacillus thermosulfidooxidans and the related acidophile, Sb. acidophilus. Faster growth rates of the novel isolates in the absence of organic carbon was considered to be a major reason why they, rather than Sb. thermosulfidooxidans (which shared many physiological characteristics) more successfully exploited conditions in the stirred tanks. Based on their phylogenetic and phenotypic characteristics, the isolates are designated strains of the proposed novel species, Sulfobacillus benefaciens, with isolate BRGM2 nominated as the type strain.

  14. 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

  15. Heavy Metal Resistance Strategies of Acidophilic Bacteria and Their Acquisition: Importance for Biomining and Bioremediation

    Directory of Open Access Journals (Sweden)

    Claudio A Navarro

    2013-01-01

    Full Text Available Microbial solubilizing of metals in acid environments is successfully used in industrial bioleaching of ores or biomining to extract metals such as copper, gold, uranium and others. This is done mainly by acidophilic and other microorganisms that mobilize metals and generate acid mine drainage or AMD, causing serious environmental problems. However, bioremediation or removal of the toxic metals from contaminated soils can be achieved by using the specific properties of the acidophilic microorganisms interacting with these elements. These bacteria resist high levels of metals by using a few "canonical" systems such as active efflux or trapping of the metal ions by metal chaperones. Nonetheless, gene duplications, the presence of genomic islands, the existence of additional mechanisms such as passive instruments for pH and cation homeostasis in acidophiles and an inorganic polyphosphate-driven metal resistance mechanism have also been proposed. Horizontal gene transfer in environmental microorganisms present in natural ecosystems is considered to be an important mechanism in their adaptive evolution. This process is carried out by different mobile genetic elements, including genomic islands (GI, which increase the adaptability and versatility of the microorganism. This mini-review also describes the possible role of GIs in metal resistance of some environmental microorganisms of importance in biomining and bioremediation of metal polluted environments such as Thiomonas arsenitoxydans, a moderate acidophilic microorganism, Acidithiobacillus caldus and Acidithiobacillus ferrooxidans strains ATCC 23270 and ATCC 53993, all extreme acidophiles able to tolerate exceptionally high levels of heavy metals. Some of these bacteria contain variable numbers of GIs, most of which code for high numbers of genes related to metal resistance. In some cases there is an apparent correlation between the number of metal resistance genes and the metal tolerance of each

  16. The study of the extreme radiation tolerance mechanisms of the bacterium Deinococcus deserti by a functional genomics approach

    International Nuclear Information System (INIS)

    Dulermo, R.

    2009-12-01

    The genome of Deinococcus deserti, a highly radiation-tolerant bacterium, was analyzed and compared to those of D. radiodurans and D. geothermalis. About 230 proteins are specifically conserved in these 3 species, including IrrE, a regulator protein essential for radio tolerance. D.deserti has several supplementary DNA repair genes, like imuY and dnaE2 (trans-lesion DNA polymerases). Moreover, D. deserti has 3 recA that code for 2 different RecA proteins (RecAC et RecAP). To study these genes, genetic tools were developed for D. deserti. Different results suggest that IrrE, required for the induction of several genes after irradiation, has peptidase activity. The 2 RecA proteins are functional for DNA repair. D. deserti is mutable by UV, which requires ImuY, DnaE2 and RecAC, but not RecAP. (author)

  17. Biosynthesis and characterization of polyhydroxyalkanoates produced by an extreme halophilic bacterium, Halomonas nitroreducens, isolated from hypersaline ponds.

    Science.gov (United States)

    Cervantes-Uc, J M; Catzin, J; Vargas, I; Herrera-Kao, W; Moguel, F; Ramirez, E; Rincón-Arriaga, S; Lizama-Uc, G

    2014-10-01

    Morphological, biochemical and genotypic characterization of a halophilic bacterium isolated from hypersaline ponds located at Las Coloradas (Río Lagartos, Yucatán, Mexico). Characterization of polymer produced by this strain was also performed. Twenty strains were isolated from water samples of salt ponds and selected based on both morphological features and their PHA storage capacity, which were determined by SEM and staining methods with Nile red and Nile blue, respectively; strains were also analysed by the fluorescence imaging technique. Among them, JCCOL25.8 strain showed the highest production of PHA's reason why phenotypic and genotypic characterization was performed; this strain was identified as Halomonas nitroreducens. Polymer produced by this strain was characterized by FTIR, DSC, GPC and EDX spectroscopy. Results indicated that the biosynthesized polymer was polyhydroxybutyrate (PHB) which had a melting peak at 170°C and a crystallinity percentage of about 36%. Based on phenotypic and genotypic aspects, JCCOL25.8 strain was identified as H. nitroreducens and it was capable to accumulate PHB. To our knowledge, there is only one study published on the biosynthesis of PHA's by H. nitroreducens strains, although the characterization of the obtained polymer was not reported. © 2014 The Society for Applied Microbiology.

  18. Thermoanaerobacter mathranii sp. nov., an ethanol-producing, extremely thermophilic anaerobic bacterium from a hot spring in Iceland

    DEFF Research Database (Denmark)

    Larsen, L.; Nielsen, P.; Ahring, B.K.

    1997-01-01

    The extremely thermophilic ethanol-producing strain A3 was isolated from a hot spring in Iceland, The cells were rod-shaped, motile, and had terminal spores: cells from the mid-to-late exponential growth phase stained gram-variable but had a gram-positive cell wall structure when viewed...

  19. Basis of genetic adaptation to heavy metal stress in the acidophilic green alga Chlamydomonas acidophila.

    Science.gov (United States)

    Puente-Sánchez, Fernando; Díaz, Silvia; Penacho, Vanessa; Aguilera, Angeles; Olsson, Sanna

    2018-07-01

    To better understand heavy metal tolerance in Chlamydomonas acidophila, an extremophilic green alga, we assembled its transcriptome and measured transcriptomic expression before and after Cd exposure in this and the neutrophilic model microalga Chlamydomonas reinhardtii. Genes possibly related to heavy metal tolerance and detoxification were identified and analyzed as potential key innovations that enable this species to live in an extremely acid habitat with high levels of heavy metals. In addition we provide a data set of single orthologous genes from eight green algal species as a valuable resource for comparative studies including eukaryotic extremophiles. Our results based on differential gene expression, detection of unique genes and analyses of codon usage all indicate that there are important genetic differences in C. acidophila compared to C. reinhardtii. Several efflux family proteins were identified as candidate key genes for adaptation to acid environments. This study suggests for the first time that exposure to cadmium strongly increases transposon expression in green algae, and that oil biosynthesis genes are induced in Chlamydomonas under heavy metal stress. Finally, the comparison of the transcriptomes of several acidophilic and non-acidophilic algae showed that the Chlamydomonas genus is polyphyletic and that acidophilic algae have distinctive aminoacid usage patterns. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Acidophilic algae isolated from mine-impacted environments and their roles in sustaining heterotrophic acidophiles

    Directory of Open Access Journals (Sweden)

    David Barrie Johnson

    2012-09-01

    Full Text Available Two acidophilic algae, identified as strains of Chlorella protothecoides var. acidicola and Euglena mutabilis, were isolated in pure culture from abandoned copper mines in Spain and Wales and grown in pH- and temperature-controlled bioreactors. The Chlorella isolate grew optimally at pH 2.5 and 30 ˚C, with a corresponding culture doubling time of 9 hours. The isolates displayed similar tolerance (10-50 mM to four transition metals tested. Growth of the algae in liquid media was paralleled with increasing concentrations of dissolved organic carbon (DOC. Glycolic acid was identified as a significant component (12- 14% of total DOC. Protracted incubation resulted in concentrations of glycolic acid declining in both cases, and glycolic acid added to a culture of Chlorella incubated in the dark was taken up by the alga (~100% within three days. Two monosaccharides were identified in cell-free liquors of each algal isolate: fructose and glucose (Chlorella, and mannitol and glucose (Euglena. These were rapidly metabolised by acidophilic heterotrophic bacteria (Acidiphilium and Acidobacterium spp. though only fructose was utilised by the more fastidious heterotroph Acidocella aromatica. The significance of algae in promoting the growth of iron- (and sulfate- reducing heterotrophic acidophiles that are important in remediating mine-impacted waters is discussed.

  1. Detection, isolation, and characterization of acidophilic methanotrophs from Sphagnum mosses.

    Science.gov (United States)

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G; Reichart, Gert-Jan; Jetten, Mike S M; Damsté, Jaap S Sinninghe; Op den Camp, Huub J M

    2011-08-15

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses.

  2. Eosin-related fluorescence of acidophil pituitary cells

    OpenAIRE

    Friedman, H.; Friedman, I.V.C.; Mello, C.V.

    1988-01-01

    The examination of haematoxylin and eosin stained sections of normal and neoplastic pituitary glands under ultraviolet light illumination discloses fluorescence of acidophil cells. The distinction between prolactin and growth hormone-producing cells is not possible. Such fluorescence depends on previous eosin staining.

  3. Genome sequence of the photoarsenotrophic bacterium Ectothiorhodospira sp. strain BSL-9, isolated from a hypersaline alkaline arsenic-rich extreme environment

    Science.gov (United States)

    Hernandez-Maldonado, Jaime; Stoneburner, Brendon; Boren, Alison; Miller, Laurence; Rosen, Michael R.; Oremland, Ronald S.; Saltikov, Chad W

    2016-01-01

    The full genome sequence of Ectothiorhodospira sp. strain BSL-9 is reported here. This purple sulfur bacterium encodes an arxA-type arsenite oxidase within the arxB2AB1CD gene island and is capable of carrying out “photoarsenotrophy” anoxygenic photosynthetic arsenite oxidation. Its genome is composed of 3.5 Mb and has approximately 63% G+C content.

  4. Thermophilic and unusually acidophilic amylase produced by a thermophilic acidophilic bacillus sp

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, F

    1982-01-01

    Bacillus sp. 11-1S, a thermophilic acidophilic bacterial strain, produced an extracellular amylase with unusual characteristics. The enzyme was purified 40-fold by SE-Sephadex column chromatography. The pH optimum for activity was 2.0, and substantial activity was noted in the pH range of 1.5-3.5. The optimal temperature was 70 degrees C, but the activity decreased markedly in lower reaction temperatures. Arrhenius plots of the reaction showed two straight lines intersecting at about 50 degrees C. The activity or stability of the enzyme was not likely to depend on Ca2+. The molecular weight of the enzyme was 54,000 calculated from the electrophoretic mobility. The enzyme behaved like an alpha-amylase (1,4-alpha-D- glucan glucanohydrolase, E.C. 3.2.1.1). About 34% of glucosidic linkages of soluble starch was hydrolyzed at 65 degrees C and pH 2.0, in 24 hours, and the major products were maltotriose and maltose. (Refs. 14).

  5. Acidophiles of saline water at thermal vents of Vulcano, Italy.

    Science.gov (United States)

    Simmons, Susan; Norris, R

    2002-06-01

    DNA was extracted from samples taken from close to acidic hydrothermal vents on shore of the Aeolian Island of Vulcano (Italy). RNA gene sequences were amplified by PCR, cloned, and sequenced. A sequence with an origin in samples at 35 degrees and 45 degrees C corresponded to that of a novel Acidithiobacillus species that was isolated from water close to the vents. Novel, iron-oxidizing mesophilic acidophiles were isolated through enrichment cultures with ferrous iron but were not represented in the clone banks of environmental rDNA. These acidophiles were related to Thiobacillus prosperus, which was isolated previously from Vulcano. The archaeal sequences that comprised a clone bank representing a high-temperature sample (75 degrees C) corresponded to those of Acidianus brierleyi and of thermophiles previously isolated from Vulcano, Thermoplasma volcanium and Acidianus infernus.

  6. Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

    2007-07-15

    The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  7. Characterization of hemicellulase and cellulase from the extremely thermophilic bacterium Caldicellulosiruptor owensensis and their potential application for bioconversion of lignocellulosic biomass without pretreatment.

    Science.gov (United States)

    Peng, Xiaowei; Qiao, Weibo; Mi, Shuofu; Jia, Xiaojing; Su, Hong; Han, Yejun

    2015-01-01

    Pretreatment is currently the common approach for improving the efficiency of enzymatic hydrolysis on lignocellulose. However, the pretreatment process is expensive and will produce inhibitors such as furan derivatives and phenol derivatives. If the lignocellulosic biomass can efficiently be saccharified by enzymolysis without pretreatment, the bioconversion process would be simplified. The genus Caldicellulosiruptor, an obligatory anaerobic and extreme thermophile can produce a diverse set of glycoside hydrolases (GHs) for deconstruction of lignocellulosic biomass. It gives potential opportunities for improving the efficiency of converting native lignocellulosic biomass to fermentable sugars. Both of the extracellular (extra-) and intracellular (intra-) enzymes of C. owensensis cultivated on corncob xylan or xylose had cellulase (including endoglucanase, cellobiohydrolase and β-glucosidase) and hemicellulase (including xylanase, xylosidase, arabinofuranosidase and acetyl xylan esterase) activities. The enzymes of C. owensensis had high ability for degrading hemicellulose of native corn stover and corncob with the conversion rates of xylan 16.7 % and araban 60.0 %. Moreover, they had remarkable synergetic function with the commercial enzyme cocktail Cellic CTec2 (Novoyzmes). When the native corn stover and corncob were respectively, sequentially hydrolyzed by the extra-enzymes of C. owensensis and CTec2, the glucan conversion rates were 31.2 and 37.9 %,which were 1.7- and 1.9-fold of each control (hydrolyzed by CTec2 alone), whereas the glucan conversion rates of the steam-exploded corn stover and corncob hydrolyzed by CTec2 alone on the same loading rate were 38.2 and 39.6 %, respectively. These results show that hydrolysis by the extra-enzyme of C. owensensis made almost the same contribution as steam-exploded pretreatment on degradation of native lignocellulosic biomass. A new process for saccharification of lignocellulosic biomass by sequential hydrolysis

  8. Solar Radiation Stress in Natural Acidophilic Biofilms of Euglena mutabilis Revealed by Metatranscriptomics and PAM Fluorometry.

    Science.gov (United States)

    Puente-Sánchez, Fernando; Olsson, Sanna; Gómez-Rodriguez, Manuel; Souza-Egipsy, Virginia; Altamirano-Jeschke, Maria; Amils, Ricardo; Parro, Victor; Aguilera, Angeles

    2016-02-01

    The daily photosynthetic performance of a natural biofilm of the extreme acidophilic Euglena mutabilis from Río Tinto (SW, Spain) under full solar radiation was analyzed by means of pulse amplitude-modulated (PAM) fluorescence measurements and metatrascriptomic analysis. Natural E. mutabilis biofilms undergo large-scale transcriptomic reprogramming during midday due to a dynamic photoinhibition and solar radiation stress. Photoinhibition is due to UV radiation and not to light intensity, as revealed by PAM fluorometry analysis. In order to minimize the negative effects of solar radiation, our data supports the presence of a circadian rhythm in this euglenophyte that increases their opportunity to survive. Differential gene expression throughout the day (at 12:00, 20:00 and night) was monitored by massive Illumina parallel sequencing of metatranscriptomic libraries. The transcription pattern was altered in genes involved in Photosystem II stability and repair, UV damaged DNA repair, non-photochemical quenching and oxidative stress, supporting the photoinhibition detected by PAM fluorometry at midday. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Sophie R Ullrich

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

  10. Metal resistance or tolerance? Acidophiles confront high metal loads via both abiotic and biotic mechanisms

    Directory of Open Access Journals (Sweden)

    Mark eDopson

    2014-04-01

    Full Text Available All metals are toxic at high concentrations and consequently their intracellular concentrations must be regulated. Acidophilic microorganisms have an optimum growth pH < 3 and proliferate in natural and anthropogenic low pH environments. Some acidophiles are involved in the catalysis of sulfide mineral dissolution, resulting in high concentrations of metals in solution. Acidophiles are often described as highly metal resistant via mechanisms such as multiple and/or more efficient active resistance systems than are present in neutrophiles. However, this is not the case for all acidophiles and we contend that their growth in high metal concentrations is partially due to an intrinsic tolerance as a consequence of the environment in which they live. In this perspective, we highlight metal tolerance via complexation of free metals by sulfate ions and passive tolerance to metal influx via an internal positive cytoplasmic transmembrane potential. These tolerance mechanisms have been largely ignored in past studies of acidophile growth in the presence of metals and should be taken into account.

  11. Biochemistry and Ecology of Novel Cytochromes Catalyzing Fe(II) Oxidation by an Acidophilic Microbial Community

    Science.gov (United States)

    Singer, S. W.; Jeans, C. J.; Thelen, M. P.; Verberkmoes, N. C.; Hettich, R. C.; Chan, C. S.; Banfield, J. F.

    2007-12-01

    An acidophilic microbial community found in the Richmond Mine at Iron Mountain, CA forms abundant biofilms in extremely acidic (pHindicated that several variants of Cyt579 were present in Leptospirillum strains. Intact protein MS analysis identified the dominant variants in each biofilm and documented multiple N-terminal cleavage sites for Cyt579. By combining biochemical, geochemical and microbiological data, we established that the sequence variation and N-terminal processing of Cyt579 are selected by ecological conditions. In addition to the soluble Cyt579, the second cytochrome appears as a much larger protein complex of ~210 kDa predominant in the biofilm membrane fraction, and has an alpha-band absorption at 572 nm. The 60 kDa cytochrome subunit, Cyt572, resides in the outer membrane of LeptoII, and readily oxidizes Fe(II) at low pH (0.95 - 3.0). Several genes encoding Cyt572 were localized within a recombination hotspot between two strains of LeptoII, causing a large range of variation in the sequences. Genomic sequencing and MS proteomic studies established that the variants were also selected by ecological conditions. A general mechanistic model for Fe(II) oxidation has been developed from these studies. Initial Fe(II) oxidation by Cyt572 occurs at the outer membrane. Cyt572 then transfers electrons to Cyt579, perhaps representing an initial step in energy flow to the biofilm community. Amino acid variations and post-translational modifications of these unique cytochromes may represent fine-tuning of function in response to local environmental conditions.

  12. The Ecology of Acidophilic Microorganisms in the Corroding Concrete Sewer Environment

    Directory of Open Access Journals (Sweden)

    Guangming Jiang

    2017-04-01

    Full Text Available Concrete corrosion is one of the most significant problems affecting valuable sewer infrastructure on a global scale. This problem occurs in the aerobic zone of the sewer, where a layer of surface corrosion develops on the exposed concrete and the surface pH is typically lowered from around 11–10 (pristine concrete to pH 2–4. Acidophilic microorganisms become established as biofilms within the concrete corrosion layer and enhance the loss of concrete mass. Until recently, the acidophilic community was considered to comprise relatively few species of microorganisms, however, the biodiversity of the corrosion community is now recognized as being extensive and varying from different sewer environmental conditions. The diversity of acidophiles in the corrosion communities includes chemolithoautotrophs, chemolithoheterotrophs, and chemoorganoheterotrophs. The activity of these microorganisms is strongly affected by H2S levels in the sewer gas phase, although CO2, organic matter, and iron in the corrosion layer influence this acidic ecosystem. This paper briefly presents the conditions within the sewer that lead to the development of concrete corrosion in that environment. The review focuses on the acidophilic microorganisms detected in sewer corrosion environments, and then summarizes their proposed functions and physiology, especially in relation to the corrosion process. To our knowledge, this is the first review of acidophilic corrosion microbial communities, in which, the ecology and the environmental conditions (when available are considered. Ecological studies of sewer corrosion are limited, however, where possible, we summarize the important metabolic functions of the different acidophilic species detected in sewer concrete corrosion layers. It is evident that microbial functions in the acidic sewer corrosion environment can be linked to those occurring in the analogous acidic environments of acid mine drainage and bioleaching.

  13. Acidophilic green alga Pseudochlorella sp. YKT1 accumulates high amount of lipid droplets under a nitrogen-depleted condition at a low-pH.

    Directory of Open Access Journals (Sweden)

    Shunsuke Hirooka

    Full Text Available Microalgal storage lipids are considered to be a promising source for next-generation biofuel feedstock. However, microalgal biodiesel is not yet economically feasible due to the high cost of production. One of the reasons for this is that the use of a low-cost open pond system is currently limited because of the unavoidable contamination with undesirable organisms. Extremophiles have an advantage in culturing in an open pond system because they grow in extreme environments toxic to other organisms. In this study, we isolated the acidophilic green alga Pseudochlorella sp. YKT1 from sulfuric acid mine drainage in Nagano Prefecture, Japan. The vegetative cells of YKT1 display the morphological characteristics of Trebouxiophyceae and molecular phylogenetic analyses indicated it to be most closely related to Pseudochlorella pringsheimii. The optimal pH and temperature for the growth of YKT1 are pH 3.0-5.0 and a temperature 20-25°C, respectively. Further, YKT1 is able to grow at pH 2.0 and at 32°C, which corresponds to the usual water temperature in the outdoors in summer in many countries. YKT1 accumulates a large amount of storage lipids (∼30% of dry weigh under a nitrogen-depleted condition at low-pH (pH 3.0. These results show that acidophilic green algae will be useful for industrial applications by acidic open culture systems.

  14. Environmental factors influenting species composition of acidophilous grasslands patches in agricultural landscape

    Czech Academy of Sciences Publication Activity Database

    Halas, Petr

    2012-01-01

    Roč. 20, č. 1 (2012), s. 16-27 ISSN 1210-8812 Institutional support: RVO:68145535 Keywords : acidophilous grasslands * hemeroby * patch isolation * patch area * regression trees Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://www.geonika.cz/EN/research/ENMgr/MGR_2012_01.pdf

  15. Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses ▿ †

    Science.gov (United States)

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; van Donselaar, Elly G.; Reichart, Gert-Jan; Jetten, Mike S. M.; Sinninghe Damsté, Jaap S.; Op den Camp, Huub J. M.

    2011-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With Sphagnum mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA, pmoA, pxmA, and mmoX gene sequences showed that the alphaproteobacterial isolates belonged to the Methylocystis and Methylosinus genera. The Methylosinus species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the Methylomonas genus, and the other strain, M200, may represent a novel genus, most closely related to the genera Methylosoma and Methylovulum. So far, no acidophilic or acid-tolerant methanotrophs in the Gammaproteobacteria class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from Sphagnum mosses. PMID:21724892

  16. A method of genetically engineering acidophilic, heterotrophic, bacteria by electroporation and conjugation

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, F.F.; Glenn, A.W.; Ward, T.E.

    1990-08-07

    A method of genetically manipulating an acidophilic bacteria is provided by two different procedures. Using electroporation, chimeric and broad-host range plasmids are introduced into Acidiphilium. Conjugation is also employed to introduce broad-host range plasmids into Acidiphilium at neutral pH.

  17. Environmental factors influencing the species composition of acidophilous grassland patches in agricultural lanscapes

    Czech Academy of Sciences Publication Activity Database

    Halas, Petr

    2012-01-01

    Roč. 20, č. 1 (2012), s. 16-27 ISSN 1210-8812 Institutional research plan: CEZ:AV0Z30860518 Keywords : acidophilous grasslands * hemeroby * patch isolation * regression trees * Bohemian-Moravian Highland Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://www.geonika.cz/CZ/CZresearch/CZMgrArchive.html

  18. Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

    Directory of Open Access Journals (Sweden)

    Carlos Vilchez

    2010-12-01

    Full Text Available Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5 that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 ´ 108 cells/mL at the end of log phase. Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 mg·mL-1 and 35 mg·mL-1, respectively. Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO2 as nitrogen and carbon sources (control cultures. Lutein accumulated up to 3.55 mg·g-1 in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.

  19. Novel cookie-with-chocolate carbon dots displaying extremely acidophilic high luminescence

    Science.gov (United States)

    Lu, Siyu; Zhao, Xiaohuan; Zhu, Shoujun; Song, Yubin; Yang, Bai

    2014-10-01

    A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+.A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03965c

  20. Genomes in Turmoil: Frugality Drives Microbial Community Structure in Extremely Acidic Environments

    Science.gov (United States)

    Holmes, D. S.

    2016-12-01

    Extremely acidic environments (To gain insight into these issues, we have conducted deep bioinformatic analyses, including metabolic reconstruction of key assimilatory pathways, phylogenomics and network scrutiny of >160 genomes of acidophiles, including representatives from Archaea, Bacteria and Eukarya and at least ten metagenomes of acidic environments [Cardenas JP, et al. pp 179-197 in Acidophiles, eds R. Quatrini and D. B. Johnson, Caister Academic Press, UK (2016)]. Results yielded valuable insights into cellular processes, including carbon and nitrogen management and energy production, linking biogeochemical processes to organismal physiology. They also provided insight into the evolutionary forces that shape the genomic structure of members of acidophile communities. Niche partitioning can explain diversity patterns in rapidly changing acidic environments such as bioleaching heaps. However, in spatially and temporally homogeneous acidic environments genome flux appears to provide deeper insight into the composition and evolution of acidic consortia. Acidophiles have undergone genome streamlining by gene loss promoting mutual coexistence of species that exploit complementarity use of scarce resources consistent with the Black Queen hypothesis [Morris JJ et al. mBio 3: e00036-12 (2012)]. Acidophiles also have a large pool of accessory genes (the microbial super-genome) that can be accessed by horizontal gene transfer. This further promotes dependency relationships as drivers of community structure and the evolution of keystone species. Acknowledgements: Fondecyt 1130683; Basal CCTE PFB16

  1. Activities of methionine-γ-lyase in the acidophilic archaeon “Ferroplasma acidarmanus” strain fer1

    Directory of Open Access Journals (Sweden)

    Khan MA

    2013-04-01

    Full Text Available M A Khan,1 Madeline M López-Muñoz,2 Charles W Kaspar,3 Kai F Hung1 1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA; 2Department of Biology, Universidad de Puerto Rico, Mayaguez, Puerto Rico; 3Bacteriology Department, University of Wisconsin, Madison, WI, USA Abstract: Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1's ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine-γ-lyase (EC 4.4.1.11, an enzyme known to carry out α, γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5'-phosphate (PLP binding domain and a partially conserved catalytic domain in both putative sequences. Detection of PLP-dependent and L-methionine-dependent production of α-keto compounds and thiol groups in fer1 confirmed the presence of methionine-γ-lyase activity. Further, fer1 lysate was capable of processing related substrates, including D-methionine, L-cysteine, L-cystathionine, and L/D-homocysteine. When the two putative fer1 methionine-γ-lyase gene-coded proteins were expressed in Escherichia coli cells, one sequence demonstrated an ability to carry out α, γ-elimination activity, while the other exhibited γ-replacement activity. These fer1 methionine-γ-lyases also exhibited optimum pH, substrate specificity, and catalytic preferences that are different from methionine-γ-lyases from other organisms. These differences are discussed in the context of molecular phylogeny constructed using a maximum

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

    Science.gov (United States)

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

    2016-01-01

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

  3. Bacterium oxidizing carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kistner, A

    1953-01-01

    Present-day knowledge of the microbiological oxidation of carbon monoxide is based on doubtful observations and imperfect experimental procedures. By making use of shake cultures in contact with gas mixtures containing high concentrations of CO and by employing liquid enrichment media with a low content of organic matter and solid media of the same composition with not more than 1.2% agar, it proved possible to isolate a co-oxidizing bacterium of the genus hydrogenomonas from sewage sludge. For the first time irrefutable proof has been given of the oxidation of carbon monoxide by a pure culture of a bacterium, both in growing cultures and in resting cell suspensions. 12 references.

  4. Heap bioleaching of uranium from low-grade granite-type ore by mixed acidophilic microbes

    International Nuclear Information System (INIS)

    Xuegang Wang; Zhongkui Zhou

    2017-01-01

    We evaluated uranium bioleaching from low-grade, granite-type uranium ore using mixed acidophilic microbes from uranium mine leachate. A 4854-ton plant-scale heap bioleaching process achieved sustained leaching with a uranium leaching efficiency of 88.3% using a pH of 1.0-2.0 and an Fe"3"+ dosage of 3.0-5.5 g/L. Acid consumption amounted to 25.8 g H_2SO_4 kg"-"1 ore. Uranium bioleaching follows a diffusion-controlled kinetic model with a correlation coefficient of 0.9136. Almost all uranium was dissolved in aqueous solution, except those encapsulated in quartz particles. Therefore, heap bioleaching by mixed acidophilic microbes enables efficient, economical, large-scale recovery of uranium from low-grade ores. (author)

  5. Evaluation of a fluorescent lectin-based staining technique for some acidophilic mining bacteria

    International Nuclear Information System (INIS)

    Fife, D.J.; Bruhn, D.F.; Miller, K.S.; Stoner, D.L.

    2000-01-01

    A fluorescence-labeled wheat germ agglutinin staining technique was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite and soil particles in the samples did not interfere with the staining procedure

  6. In a Quest for Engineering Acidophiles for Biomining Applications: Challenges and Opportunities

    Science.gov (United States)

    Gumulya, Yosephine; Boxall, Naomi J; Khaleque, Himel N; Santala, Ville; Carlson, Ross P; Kaksonen, Anna H

    2018-01-01

    Biomining with acidophilic microorganisms has been used at commercial scale for the extraction of metals from various sulfide ores. With metal demand and energy prices on the rise and the concurrent decline in quality and availability of mineral resources, there is an increasing interest in applying biomining technology, in particular for leaching metals from low grade minerals and wastes. However, bioprocessing is often hampered by the presence of inhibitory compounds that originate from complex ores. Synthetic biology could provide tools to improve the tolerance of biomining microbes to various stress factors that are present in biomining environments, which would ultimately increase bioleaching efficiency. This paper reviews the state-of-the-art tools to genetically modify acidophilic biomining microorganisms and the limitations of these tools. The first part of this review discusses resilience pathways that can be engineered in acidophiles to enhance their robustness and tolerance in harsh environments that prevail in bioleaching. The second part of the paper reviews the efforts that have been carried out towards engineering robust microorganisms and developing metabolic modelling tools. Novel synthetic biology tools have the potential to transform the biomining industry and facilitate the extraction of value from ores and wastes that cannot be processed with existing biomining microorganisms. PMID:29466321

  7. Familial relationships in hyperthermo- and acidophilic archaeal viruses

    DEFF Research Database (Denmark)

    Happonen, Lotta Johanna; Redder, Peter; Peng, Xu

    2010-01-01

    Archaea often live in extreme, harsh environments such as acidic hot springs and hypersaline waters. To date, only two icosahedrally symmetric, membrane-containing archaeal viruses, SH1 and Sulfolobus turreted icosahedral virus (STIV), have been described in detail. We report the sequence and thr...

  8. Cloning and expression of acidstable, high maltose-forming, Ca2+-independent α-amylase from an acidophile Bacillus acidicola and its applicability in starch hydrolysis.

    Science.gov (United States)

    Sharma, Archana; Satyanarayana, T

    2012-05-01

    The α-amylase encoding gene from acidophilic bacterium Bacillus acidicola was cloned into pET28a(+) vector and expressed in Escherichia coli BL21 (DE3). The recombinant E. coli produced a 15-fold higher α-amylase than B. acidicola strain. The recombinant α-amylase was purified to homogeneity by one-step nickel affinity chromatography using Ni(2+)-NTA resin with molecular mass of 62 KDa. It is active in the pH range between 3.0 and 7.0 and 30 and 100 °C with optimum at pH 4.0 and 60 °C. The enzyme is Ca(2+)-independent with K (m) and k (cat) values (on soluble starch) of 1.6 mg ml(-1) and 108.7 s(-1), respectively. The α-amylase of B. acidicola is acidstable, high maltose forming and Ca(2+)-independent, and therefore, is a suitable candidate for starch hydrolysis and baking.

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

    Science.gov (United States)

    Bonnefoy, Violaine; Holmes, David S

    2012-07-01

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

  10. Redox transformations of iron at extremely low pH: fundamental and applied aspects

    Directory of Open Access Journals (Sweden)

    D. Barrie eJohnson

    2012-03-01

    Full Text Available Many different species of acidophilic prokaryotes, widely distributed within the domains Bacteria and Archaea, can catalyze the dissimilatory oxidation of ferrous iron or reduction of ferric iron, or can do both. Microbially-mediated cycling of iron in extremely acidic environments (pH <3 is strongly influenced by the enhanced chemical stability of ferrous iron and far greater solubility of ferric iron under such conditions. Cycling of iron has been demonstrated in vitro using both pure and mixed cultures of acidophiles, and there is considerable evidence that active cycling of iron occurs in acid mine drainage streams, pit lakes and iron-rich acidic rivers, such as the Rio Tinto. Measurements of specific rates of iron oxidation and reduction by acidophilic microorganisms show that different species vary in their capacities for iron oxido-reduction, and that this is influenced by the electron donor provided and growth conditions used. These measurements, and comparison with corresponding data for oxidation of reduced sulfur compounds, also help explain why ferrous iron is usually used preferentially as an electron donor by acidophiles that can oxidize both iron and sulfur, even though the energy yield from oxidizing iron is much smaller than that available from sulfur oxidation. Iron-oxidizing acidophiles have been used in biomining (a technology that harness their abilities to accelerate the oxidative dissolution of sulfidic minerals and thereby facilitate the extraction of precious and base metals for several decades. More recently they have also been used to simultaneously remediate iron-contaminated surface and ground-waters and produce a useful mineral by-product (schwertmannite. Bioprocessing of oxidized mineral ores using acidophiles that bring about the reductive dissolution of ferric iron minerals such as goethite has also recently been demonstrated, and new biomining technologies based on this approach are being developed.

  11. Growth rate characteristics of acidophilic heterotrophic organisms from mine waste rock piles

    Science.gov (United States)

    Yacob, T. W.; Silverstein, J.; Jenkins, J.; Andre, B. J.; Rajaram, H.

    2010-12-01

    Autotrophic iron oxidizing bacteria play a key role in pyrite oxidation and generation of acid mine drainage AMD. Scarcity of organic substrates in many disturbed sites insures that IOB have sufficient oxygen and other nutrients for growth. It is proposed that addition of organic carbon substrate to waste rock piles will result in enrichment of heterotrophic microorganisms limiting the role of IOB in AMD generation. Previous researchers have used the acidophilic heterotroph Acidiphilium cryptum as a model to study the effects of organic substrate addition on the pyrite oxidation/AMD cycle. In order to develop a quantitative model of effects such as competition for oxygen, it is necessary to use growth and substrate consumption rate expressions, and one approach is to choose a model strain such as A. cryptum for kinetic studies. However we have found that the growth rate characteristics of A. cryptum may not provide an accurate model of the remediation effects of organic addition to subsurface mined sites. Fluorescent in-situ hybridization (FISH) assays of extracts of mine waste rock enriched with glucose and yeast extract did not produce countable numbers of cells in the Acidiphilium genus, with a detection limit of3 x 104 cells/gram rock, despite evidence of the presence of well established heterotrophic organisms. However, an MPN enrichment produced heterotrophic population estimates of 1x107 and 1x109 cells/gram rock. Growth rate studies of A. cryptum showed that cultures took 120 hours to degrade 50% of an initial glucose concentration of 2,000 mg/L. However a mixed culture enriched from mine waste rock consumed 100% of the same amount of glucose in 24 hours. Substrate consumption data for the mixed culture were fit to a Monod growth model: {dS}/{dt} = μ_{max}S {( {X_0}/{Y} + S_0 -S )}/{(K_s +S)} Kinetic parameters were estimated utilizing a non linear regression method coupled with an ODE solver. The maximum specific growth rate of the mixed population with

  12. Enhanced bioleaching on attachment of indigenous acidophilic bacteria to pyrite surface

    Science.gov (United States)

    Wi, D. W.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

    2012-04-01

    In recent years, bioleaching has been widely applied on an industrial scale due to the advantages of low cost and environment friendliness. The direct contact mechanism of bioleaching assumes the action of a metal sulfide-attached cell oxidizing the mineral by an enzyme system with oxygen to sulfate and metal cations. Fundamental surface properties of sulfide particles and leaching-bacteria in bioleaching play the key role in the efficiency of this process. The aim of this work is to investigate of direct contact bioleaching mechanism on pyrite through attachment properties between indigenous acidophilic bacteria and pyrite surfaces. The bacteria were obtained from sulfur hot springs, Hatchobaru thermal electricity plant in Japan. And pyrite was collected from mine waste from Gwang-yang abandoned gold mines, Korea. In XRD analyses of the pyrite, x-ray diffracted d-value belong to pyrite was observed. The indigenous acidophilic bacteria grew well in a solution and over the course of incubation pH decreased and Eh increased. In relation to a bacterial growth-curve, the lag phase was hardly shown while the exponential phase was very fast. Bioleaching experiment result was showed that twenty days after the indigenous acidophilic bacteria were inoculated to a pyrite-leaching medium, the bacterial sample had a greater concentration of Fe and Zn than within the control sample. In SEM-EDS analyses, rod-shaped bacteria and round-shaped microbes were well attached to the surface of pyrite. The size of the rod-shaped bacteria ranged from 1.05~1.10 ? to 4.01~5.38 ?. Round-shaped microbes were more than 3.0 ? in diameter. Paired cells of rod-shaped bacteria were attached to the surface of pyrite linearly.

  13. Photochemical performance of the acidophilic red alga Cyanidium sp. in a pH gradient

    Czech Academy of Sciences Publication Activity Database

    Kvíderová, Jana

    2012-01-01

    Roč. 42, č. 2-3 (2012), s. 223-234 ISSN 0169-6149. [European Workshop on Astrobiology of the European- Astrobiology -Network-Association (EANA) /11/. German Aerosp Ctr, Cologne, 11.07.2011-14.07.2011] R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : acidophilic red alga * pH gradient * photochemistry Subject RIV: EF - Botanics Impact factor: 1.831, year: 2012

  14. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    International Nuclear Information System (INIS)

    Mishra, Debaraj; Kim, Dong J.; Ralph, David E.; Ahn, Jong G.; Rhee, Young H.

    2008-01-01

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO 3 . Bioleach residues were characterized by EDX and XRD

  15. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Debaraj [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Dong J. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of)], E-mail: djkim@kigam.re.kr; Ralph, David E. [AJ Parker CRC for Hydrometallurgy, Murdoch University, South Street Murdoch, Perth 6153 (Australia); Ahn, Jong G. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Rhee, Young H. [Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2008-04-15

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO{sub 3}. Bioleach residues were characterized by EDX and XRD.

  16. Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

    International Nuclear Information System (INIS)

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T.; Hiraishi, A.

    2014-01-01

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at −1 was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process

  17. Production of biosurfactant on crude date syrup under saline conditions by entrapped cells of Natrialba sp. strain E21, an extremely halophilic bacterium isolated from a solar saltern (Ain Salah, Algeria).

    Science.gov (United States)

    Kebbouche-Gana, Salima; Gana, Mohamed Lamine; Ferrioune, Imen; Khemili, Souad; Lenchi, Nesrine; Akmouci-Toumi, Sihem; Bouanane-Darenfed, Nabila Amel; Djelali, Nacer-Eddine

    2013-11-01

    A bacterial strain E21 was isolated from a sample of water collected in the salt lake located close to Ain Salah, Algeria. The analysis of 16S rRNA gene sequence had indicated that the strain had 93 % sequence similarity with the genus Natrialba sp. strain E21 (GenBank, FR750525.1) and was considered extremely halophilic. Production of biosurfactant by the strain E21 with free and entrapped cells was investigated using soluble starch in the saline conditions. Biosurfactant synthesis was followed by measuring the surface tension and emulsifying index 9 days under optimal conditions (40 °C, pH 7). Some diffusional limitations in alginate and agar beads affected the kinetics of biosurfactant production when compared to that obtained with free cells culture. The minimum values of surface tension were 27 and 30 mN m(-1) achieved after 9 days with free and immobilized cells, respectively, while the corresponding maximum E24 values were 65.3 and 62.3 %, respectively. The re-use of bacterial cells along with the limited cell losses provided by the immobilized system might lead to significant reduction of the biosurfactant production cost.

  18. FY1995 acquisition of useful and high ability genes for acidophilic bacteria; 1995 nendo kosansei saikin ni takai noryoku wo fuyosuru idenshi no kakutoku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The purpose of this project is to obtain and to study useful and high ability genes which can use for gene engineering of acidophilic bacteria. 130 isolates of acidophilic bacteria (major species are iron-oxidizing bacteria) were isolated from various environment. 10 isolates of iron-oxidizing bacteria were selected in the point of high ferrous iron oxidizing ability and heavy metal tolerance. Mercury ion resistance genes of iron-oxidizing bacteria were identified and cloned in E.coli. Sequencing analysis and functional identification of gene products were performed. These genes are thought to be useful for selection marker of gen engineering of acidophilic bacteria. (NEDO)

  19. Redox transformations of iron at extremely low pH: fundamental and applied aspects

    OpenAIRE

    Johnson, D. Barrie; Kanao, Tadayoshi; Hedrich, Sabrina

    2012-01-01

    Many different species of acidophilic prokaryotes, widely distributed within the domains Bacteria and Archaea, can catalyze the dissimilatory oxidation of ferrous iron or reduction of ferric iron, or can do both. Microbially-mediated cycling of iron in extremely acidic environments (pH <3) is strongly influenced by the enhanced chemical stability of ferrous iron and far greater solubility of ferric iron under such conditions. Cycling of iron has been demonstrated in vitro using both pure a...

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

    Energy Technology Data Exchange (ETDEWEB)

    Frank F. Roberto

    2008-08-01

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

  1. Optimized Production of Xylitol from Xylose Using a Hyper-Acidophilic Candida tropicalis

    Directory of Open Access Journals (Sweden)

    Elena Tamburini

    2015-08-01

    Full Text Available The yeast Candida tropicalis DSM 7524 produces xylitol, a natural, low-calorie sweetener, by fermentation of xylose. In order to increase xylitol production rate during the submerged fermentation process, some parameters-substrate (xylose concentration, pH, aeration rate, temperature and fermentation strategy-have been optimized. The maximum xylitol yield reached at 60–80 g/L initial xylose concentration, pH 5.5 at 37 °C was 83.66% (w/w on consumed xylose in microaerophilic conditions (kLa = 2·h−1. Scaling up on 3 L fermenter, with a fed-batch strategy, the best xylitol yield was 86.84% (w/w, against a 90% of theoretical yield. The hyper-acidophilic behaviour of C. tropicalis makes this strain particularly promising for industrial application, due to the possibility to work in non-sterile conditions.

  2. Optimized Production of Xylitol from Xylose Using a Hyper-Acidophilic Candida tropicalis.

    Science.gov (United States)

    Tamburini, Elena; Costa, Stefania; Marchetti, Maria Gabriella; Pedrini, Paola

    2015-08-19

    The yeast Candida tropicalis DSM 7524 produces xylitol, a natural, low-calorie sweetener, by fermentation of xylose. In order to increase xylitol production rate during the submerged fermentation process, some parameters-substrate (xylose) concentration, pH, aeration rate, temperature and fermentation strategy-have been optimized. The maximum xylitol yield reached at 60-80 g/L initial xylose concentration, pH 5.5 at 37 °C was 83.66% (w/w) on consumed xylose in microaerophilic conditions (kLa = 2·h(-1)). Scaling up on 3 L fermenter, with a fed-batch strategy, the best xylitol yield was 86.84% (w/w), against a 90% of theoretical yield. The hyper-acidophilic behaviour of C. tropicalis makes this strain particularly promising for industrial application, due to the possibility to work in non-sterile conditions.

  3. [Leaching of nonferrous metals from copper-smelting slag with acidophilic microorganisms].

    Science.gov (United States)

    Murav'ev, M I; Fomchenko, N V

    2013-01-01

    The leaching process of copper and zinc from copper converter slag with sulphuric solutions of trivalent iron sulphate obtained using the association of acidophilic chemolithotrophic microorganisms was investigated. The best parameters of chemical leaching (temperature 70 degrees C, an initial concentration of trivalent iron in the leaching solution of 10.1 g/L, and a solid-phase content in the suspension of 10%) were selected. Carrying out the process under these parameters resulted in the recovery of 89.4% of copper and 39.3% of zinc in the solution. The possibility of the bioregeneration of trivalent iron in the solution obtained after the chemical leaching of slag by iron-oxidizingacidophilic chemolithotrophic microorganisms without inhibiting their activity was demonstrated.

  4. Influence of water chemistry on the distribution of an acidophilic protozoan in an acid mine drainage system at the abandoned Green Valley coal mine, Indiana, USA

    Energy Technology Data Exchange (ETDEWEB)

    Brake, S.S.; Dannelly, H.K.; Connors, K.A.; Hasiotis, S.T. [Indiana State University, Terre Haute, IN (United States). Dept. of Geography Geology & Anthropology

    2001-07-01

    Euglena mutabilis, a benthic photosynthetic protozoan that intracellularly sequesters Fe, is variably abundant in the main effluent channel that contains acid mine drainage (AMD) discharging from the Green Valley coal mine site in western Indiana. Samples of effluent (pH 3.0-4.6) taken from the main channel and samples of contaminated stream water (pH 3.3 to 8.0) collected from an adjacent stream were analyzed to evaluate the influence of water chemistry on E. mutabilis distribution. E. mutabilis communities were restricted to areas containing unmixed effluent with the thickest (up to 3 mm) benthic communities residing in effluent containing high concentrations of total Fe (up to 12110 mg/l), SO{sub 4}(up to 2940 mg/l), Al (up to 1846 mg/l), and Cl (up to 629 mg/l). Communities were also present, but much less abundant, in areas with effluent containing lower concentrations of these same constituents. In effluent where SO{sub 4} was most highly concentrated, E. mutabilis was largely absent, suggesting that extremely high concentrations of SO{sub 4} may have an adverse effect on this potentially beneficial Fe-mediating, acidophilic protozoan.

  5. Lactococcus lactis - a diploid bacterium

    DEFF Research Database (Denmark)

    Michelsen, Ole; Hansen, Flemming G.; Jensen, Peter Ruhdal

    the next division. Thus, the regions of the chromosome that are the last to be replicated are haploid even in fast-growing bacteria. In contrast to this general rule for bacteria, we found that Lactococcus lactis, a bacterium which has been exploited for thousands of years for the production of fermented...... milk products, is born with two complete non-replicating chromosomes. L. lactis therefore remain diploid throughout its entire life cycle....

  6. Effect of adaptation and pulp density on bioleaching of mine waste using indigenous acidophilic bacteria

    Science.gov (United States)

    Cho, K.; Kim, B.; Lee, D.; Choi, N.; Park, C.

    2011-12-01

    Adaptation to environment is a natural phenomena that takes place in many animals, plants and microorganisms. These adapted organisms achieve stronger applicability than unadapted organisms after habitation in a specific environment for a long time. In the biohydrometallurgical industry, adaptation to special environment conditions by selective culturing is the most popular method for improving bioleaching activity of strains-although that is time consuming. This study investigated the influence of the bioleaching efficiency of mine waste under batch experimental conditions (adaptation and pulp density) using the indigenous acidophilic bacteria collected from acid mine drainage in Go-seong and Yeon-hwa, Korea. We conducted the batch experiments at the influences of parameters, such as the adaptation of bacteria and pulp density of the mine waste. In the adaptation case, the value of pH in 1'st adaptation bacteria sample exhibited lower than in 2'nd adaptation bacteria sample. And the content of both Cu and Zn at 1'st adaptation bacteria sample appeared lower than at 2'nd adaptation bacteria sample. In the SEM analysis, the rod-shaped bacteria with 1μm in length were observed on the filter paper (pore size - 0.45μm). The results of pulp density experiments revealed that the content of both Cu and Zn increased with increasing pulp density, since the increment of pulp density resulted in the enhancement of bioleaching capacity.

  7. Toxicity of Select Organic Acids to the Slightly Thermophilic Acidophile Acidithiobaccillus Caldus

    Energy Technology Data Exchange (ETDEWEB)

    John E Aston; William A Apel; Brady D Lee; Brent M Peyton

    2009-02-01

    Acidithiobacillus caldus is a thermophilic acidophile found in commercial biomining, acid mine drainage systems, and natural environments. Previous work has characterized A. caldus as a chemolithotrophic autotroph capable of utilizing reduced sulfur compounds under aerobic conditions. Organic acids are especially toxic to chemolithotrophs in low-pH environments, where they diffuse more readily into the cell and deprotonate within the cytoplasm. In the present study, the toxic effects of oxaloacetate, pyruvate, 2-ketoglutarate, acetate, malate, succinate, and fumarate on A. caldus strain BC13 were examined under batch conditions. All tested organic acids exhibited some inhibitory effect. Oxaloacetate was observed to inhibit growth completely at a concentration of 250 µM, whereas other organic acids were completely inhibitory at concentrations of between 1,000 and 5,000 µM. In these experiments, the measured concentrations of organic acids decreased with time, indicating uptake or assimilation by the cells. Phospholipid fatty acid analyses indicated an effect of organic acids on the cellular envelope. Notable differences included an increase in cyclic fatty acids in the presence of organic acids, indicating possible instability of the cellular envelope. This was supported by field emission scanning-electron micrographs showing blebbing and sluffing in cells grown in the presence of organic acids.

  8. Effect of physical characteristics on bioleaching using indigenous acidophilic bacteria for recovering the valuable resources

    Science.gov (United States)

    Wi, D.; Kim, B.; Cho, K.; Choi, N.; Park, C.

    2011-12-01

    Bioleaching technology which is based on the ability of bacteria to transform solid compounds into soluble or extractable elements that can be recovered, has developed rapidly in recent decades for its advantages, such as mild reaction, low energy consumption, simple process, environmentally friendly and suitable for low-grade mine tailing and residues. This study investigated the bioleaching efficiency of copper matte under batch experimental conditions (various mineral particle size) using the indigenous acidophilic bacteria collected from acidic hot spring in Hatchnobaru, Japan. We conducted the batch experiments at three different mineral particle sizes: 0.06, 0.16 and 1.12mm. The results showed that the pH in the bacteria inoculating sample increased than initial condition, possibly due to buffer effects by phosphate ions in growth medium. After 22 days from incubation the leached accumulation content of Cu was 0.06 mm - 1,197 mg/L, 0.16 mm - 970 mg/L and 1.12 mm - 704 mg/L. Additionally, through SEM analysis we found of gypsum formed crystals which coated the copper matte surface 6 days after inoculation in 1.12mm case. This study informs basic knowledge when bacteria apply to eco-/economic resources utilization studies including the biomining and the recycling of mine waste system.

  9. Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

    Energy Technology Data Exchange (ETDEWEB)

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580 (Japan); Hiraishi, A. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan and Electronics-inspired Interdisciplinary Institute (EIIRIS), Toyohashi University of Technology, Toyohashi 441-8580 (Japan)

    2014-02-20

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at < pH 4 and harboring bacteria of the candidate phylum 'TM7' as the major constituents of the microbial community. In light of the fact that the 16S rRNA of TM7 bacteria has a highly atypical base substitution possibly responsible for resistance to streptomycin at the ribosome level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L{sup −1} was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

  10. Propyl gallate synthesis using acidophilic tannase and simultaneous production of tannase and gallic acid by marine Aspergillus awamori BTMFW032.

    Science.gov (United States)

    Beena, P S; Basheer, Soorej M; Bhat, Sarita G; Bahkali, Ali H; Chandrasekaran, M

    2011-07-01

    Marine Aspergillus awamori BTMFW032, recently reported by us, produce acidophilic tannase as extracellular enzyme. Here, we report the application of this enzyme for synthesis of propyl gallate by direct transesterification of tannic acid and in tea cream solubilisation besides the simultaneous production of gallic acid along with tannase under submerged fermentation by this fungus. This acidophilic tannase enabled synthesis of propyl gallate by direct transesterification of tannic acid using propanol as organic reaction media under low water conditions. The identity of the product was confirmed with thin layer chromatography and Fourier transform infrared spectroscopy. It was noted that 699 U/ml of enzyme could give 60% solubilisation of tea cream within 1 h. Enzyme production medium was optimized adopting Box-Behnken design for simultaneous synthesis of tannase and gallic acid. Process variables including tannic acid, sodium chloride, ferrous sulphate, dipotassium hydrogen phosphate, incubation period and agitation were recognized as the critical factors that influenced tannase and gallic acid production. The model obtained predicted 4,824.61 U/ml of tannase and 136.206 μg/ml gallic acid after 48 h of incubation, whereas optimized medium supported 5,085 U/ml tannase and 372.6 μg/ml of gallic acid production after 36 and 84 h of incubation, respectively, with a 15-fold increase in both enzyme and gallic acid production. Results indicated scope for utilization of this acidophilic tannase for transesterification of tannic acid into propyl gallate, tea cream solubilisation and simultaneous production of gallic acid along with tannase.

  11. [Hydrogen production and enzyme activity of acidophilic strain X-29 at different C/N ratio].

    Science.gov (United States)

    Li, Qiu-bo; Xing, De-feng; Ren, Nan-qi; Zhao, Li-hua; Song, Ye-ying

    2006-04-01

    Some fermentative bacteria can produce hydrogen by utilizing carbohydrate and other kinds of organic compounds as substrates. Hydrogen production was also determined by both the limiting of growth and related enzyme activity in energy metabolism. Carbon and nitrogen are needed for the growth and metabolism of microorganisms. In addition, the carbon/nitrogen (C/N) ratio can influence the material metabolized and the energy produced. In order to improve the hydrogen production efficiency of the bacteria, we analyzed the effect of different C/N ratios on hydrogen production and the related enzyme activities in the acidophilic strain X-29 using batch test. The results indicate that the differences in the metabolism level and enzyme activity are obvious at different C/N ratios. Although the difference in liquid fermentative products produced per unit of biomass is not obvious, hydrogen production is enhanced at a specifically determined ratio. At a C/N ratio of 14 the accumulative hydrogen yield of strain X-29 reaches the maximum, 2210.9 mL/g. At different C/N ratios, the expression of hydrogenase activity vary; the activity of hydrogenase decrease quickly after reaching a maximum along with the fermentation process, but the time of expression is short. The activity of alcohol dehydrogenase (ADH) tend to stabilize after reaching a peak along with the fermentation process, the difference in expression activity is little, and the expression period is long at different C/N ratios. At a C/N ratio of 14 hydrogenase and ADH reach the maximum 2.88 micromol x (min x mg)(-1) and 33.2 micromol x (min x mg)(-1), respectively. It is shown that the C/N ratio has an important effect on enhancing hydrogen production and enzyme activity.

  12. Comparative Genomics Unravels the Functional Roles of Co-occurring Acidophilic Bacteria in Bioleaching Heaps

    Science.gov (United States)

    Zhang, Xian; Liu, Xueduan; Liang, Yili; Xiao, Yunhua; Ma, Liyuan; Guo, Xue; Miao, Bo; Liu, Hongwei; Peng, Deliang; Huang, Wenkun; Yin, Huaqun

    2017-01-01

    The spatial-temporal distribution of populations in various econiches is thought to be potentially related to individual differences in the utilization of nutrients or other resources, but their functional roles in the microbial communities remain elusive. We compared differentiation in gene repertoire and metabolic profiles, with a focus on the potential functional traits of three commonly recognized members (Acidithiobacillus caldus, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans) in bioleaching heaps. Comparative genomics revealed that intra-species divergence might be driven by horizontal gene transfer. These co-occurring bacteria shared a few homologous genes, which significantly suggested the genomic differences between these organisms. Notably, relatively more genes assigned to the Clusters of Orthologous Groups category [G] (carbohydrate transport and metabolism) were identified in Sulfobacillus thermosulfidooxidans compared to the two other species, which probably indicated their mixotrophic capabilities that assimilate both organic and inorganic forms of carbon. Further inspection revealed distinctive metabolic capabilities involving carbon assimilation, nitrogen uptake, and iron-sulfur cycling, providing robust evidence for functional differences with respect to nutrient utilization. Therefore, we proposed that the mutual compensation of functionalities among these co-occurring organisms might provide a selective advantage for efficiently utilizing the limited resources in their habitats. Furthermore, it might be favorable to chemoautotrophs' lifestyles to form mutualistic interactions with these heterotrophic and/or mixotrophic acidophiles, whereby the latter could degrade organic compounds to effectively detoxify the environments. Collectively, the findings shed light on the genetic traits and potential metabolic activities of these organisms, and enable us to make some inferences about genomic and functional differences that might

  13. Comparative Genomics Unravels the Functional Roles of Co-occurring Acidophilic Bacteria in Bioleaching Heaps

    Directory of Open Access Journals (Sweden)

    Xian Zhang

    2017-05-01

    Full Text Available The spatial-temporal distribution of populations in various econiches is thought to be potentially related to individual differences in the utilization of nutrients or other resources, but their functional roles in the microbial communities remain elusive. We compared differentiation in gene repertoire and metabolic profiles, with a focus on the potential functional traits of three commonly recognized members (Acidithiobacillus caldus, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans in bioleaching heaps. Comparative genomics revealed that intra-species divergence might be driven by horizontal gene transfer. These co-occurring bacteria shared a few homologous genes, which significantly suggested the genomic differences between these organisms. Notably, relatively more genes assigned to the Clusters of Orthologous Groups category [G] (carbohydrate transport and metabolism were identified in Sulfobacillus thermosulfidooxidans compared to the two other species, which probably indicated their mixotrophic capabilities that assimilate both organic and inorganic forms of carbon. Further inspection revealed distinctive metabolic capabilities involving carbon assimilation, nitrogen uptake, and iron-sulfur cycling, providing robust evidence for functional differences with respect to nutrient utilization. Therefore, we proposed that the mutual compensation of functionalities among these co-occurring organisms might provide a selective advantage for efficiently utilizing the limited resources in their habitats. Furthermore, it might be favorable to chemoautotrophs' lifestyles to form mutualistic interactions with these heterotrophic and/or mixotrophic acidophiles, whereby the latter could degrade organic compounds to effectively detoxify the environments. Collectively, the findings shed light on the genetic traits and potential metabolic activities of these organisms, and enable us to make some inferences about genomic and functional

  14. Molecular identification of phosphate solubilizing bacterium ...

    African Journals Online (AJOL)

    A phosphate solubilizing bacterium was isolated from the rhizosphere soil of upland rice and identified by 16S rRNA gene sequencing. The gene sequence showed 99% homology with Alcaligenes faecalis. Based on the gene sequence homology, it was identified as A. faecalis. Interaction effect of this bacterium on growth ...

  15. Investigation of energy gene expressions and community structures of free and attached acidophilic bacteria in chalcopyrite bioleaching.

    Science.gov (United States)

    Zhu, Jianyu; Jiao, Weifeng; Li, Qian; Liu, Xueduan; Qin, Wenqing; Qiu, Guanzhou; Hu, Yuehua; Chai, Liyuan

    2012-12-01

    In order to better understand the bioleaching mechanism, expression of genes involved in energy conservation and community structure of free and attached acidophilic bacteria in chalcopyrite bioleaching were investigated. Using quantitative real-time PCR, we studied the expression of genes involved in energy conservation in free and attached Acidithiobacillus ferrooxidans during bioleaching of chalcopyrite. Sulfur oxidation genes of attached A. ferrooxidans were up-regulated while ferrous iron oxidation genes were down-regulated compared with free A. ferrooxidans in the solution. The up-regulation may be induced by elemental sulfur on the mineral surface. This conclusion was supported by the results of HPLC analysis. Sulfur-oxidizing Acidithiobacillus thiooxidans and ferrous-oxidizing Leptospirillum ferrooxidans were the members of the mixed culture in chalcopyrite bioleaching. Study of the community structure of free and attached bacteria showed that A. thiooxidans dominated the attached bacteria while L. ferrooxidans dominated the free bacteria. With respect to available energy sources during bioleaching of chalcopyrite, sulfur-oxidizers tend to be on the mineral surfaces whereas ferrous iron-oxidizers tend to be suspended in the aqueous phase. Taken together, these results indicate that the main role of attached acidophilic bacteria was to oxidize elemental sulfur and dissolution of chalcopyrite involved chiefly an indirect bioleaching mechanism.

  16. Mandelbrot's Extremism

    NARCIS (Netherlands)

    Beirlant, J.; Schoutens, W.; Segers, J.J.J.

    2004-01-01

    In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

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

    Directory of Open Access Journals (Sweden)

    Mrážiková A.

    2016-03-01

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

  18. [Bioregeneration of the solutions obtained during the leaching of nonferrous metals from waste slag by acidophilic microorganisms].

    Science.gov (United States)

    Fomchenko, N V; Murav'ev, M I; Kondrat'eva, T F

    2014-01-01

    The bioregeneration of the solutions obtained after the leaching of copper and zinc from waste slag by sulfuric solutions of ferric sulfate is examined. For bioregeneration, associations of mesophilic and moderately thermqophilic acidophilic chemolithotrophic microorganisms were made. It has been shown that the complete oxidation of iron ions in solutions obtained after the leaching of nonferrous metals from waste slag is possible at a dilution of the pregnant solution with a nutrient medium. It has been found that the maximal rate of oxidation of iron ions is observed at the use of a mesophilic association of microorganisms at a threefold dilution of the pregnant solution with a nutrient medium. The application ofbioregeneration during the production of nonferrous metals from both waste and converter slags would make it possible to approach the technology of their processing using the closed cycle of workflows.

  19. Gene Identification and Substrate Regulation Provide Insights into Sulfur Accumulation during Bioleaching with the Psychrotolerant Acidophile Acidithiobacillus ferrivorans

    Science.gov (United States)

    Liljeqvist, Maria; Rzhepishevska, Olena I.

    2013-01-01

    The psychrotolerant acidophile Acidithiobacillus ferrivorans has been identified from cold environments and has been shown to use ferrous iron and inorganic sulfur compounds as its energy sources. A bioinformatic evaluation presented in this study suggested that Acidithiobacillus ferrivorans utilized a ferrous iron oxidation pathway similar to that of the related species Acidithiobacillus ferrooxidans. However, the inorganic sulfur oxidation pathway was less clear, since the Acidithiobacillus ferrivorans genome contained genes from both Acidithiobacillus ferrooxidans and Acidithiobacillus caldus encoding enzymes whose assigned functions are redundant. Transcriptional analysis revealed that the petA1 and petB1 genes (implicated in ferrous iron oxidation) were downregulated upon growth on the inorganic sulfur compound tetrathionate but were on average 10.5-fold upregulated in the presence of ferrous iron. In contrast, expression of cyoB1 (involved in inorganic sulfur compound oxidation) was decreased 6.6-fold upon growth on ferrous iron alone. Competition assays between ferrous iron and tetrathionate with Acidithiobacillus ferrivorans SS3 precultured on chalcopyrite mineral showed a preference for ferrous iron oxidation over tetrathionate oxidation. Also, pure and mixed cultures of psychrotolerant acidophiles were utilized for the bioleaching of metal sulfide minerals in stirred tank reactors at 5 and 25°C in order to investigate the fate of ferrous iron and inorganic sulfur compounds. Solid sulfur accumulated in bioleaching cultures growing on a chalcopyrite concentrate. Sulfur accumulation halted mineral solubilization, but sulfur was oxidized after metal release had ceased. The data indicated that ferrous iron was preferentially oxidized during growth on chalcopyrite, a finding with important implications for biomining in cold environments. PMID:23183980

  20. Pyrophosphate as a central energy carrier in the hydrogen-producing extremely thermophilic Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Bielen, A.A.M.; Willquist, K.; Engman, J.; Oost, van der J.; Niel, van E.W.J.; Kengen, S.W.M.

    2010-01-01

    The role of inorganic pyrophosphate (PPi) as an energy carrier in the central metabolism of the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was investigated. In agreement with its annotated genome sequence, cell extracts were shown to exhibit PPi-dependent

  1. Substrate and product inhibition of hydrogen production by the extreme thermophile, Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Niel, van E.W.J.; Claassen, P.A.M.; Stams, A.J.M.

    2003-01-01

    Substrate and product inhibition of hydrogen production during sucrose fermentation by the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was studied. The inhibition kinetics were analyzed with a noncompetitive, nonlinear inhibition model. Hydrogen was the most severe

  2. Sustainable biorefining in wastewater by engineered extreme alkaliphile Bacillus marmarensis.

    Science.gov (United States)

    Wernick, David G; Pontrelli, Sammy P; Pollock, Alexander W; Liao, James C

    2016-02-01

    Contamination susceptibility, water usage, and inability to utilize 5-carbon sugars and disaccharides are among the major obstacles in industrialization of sustainable biorefining. Extremophilic thermophiles and acidophiles are being researched to combat these problems, but organisms which answer all the above problems have yet to emerge. Here, we present engineering of the unexplored, extreme alkaliphile Bacillus marmarensis as a platform for new bioprocesses which meet all these challenges. With a newly developed transformation protocol and genetic tools, along with optimized RBSs and antisense RNA, we engineered B. marmarensis to produce ethanol at titers of 38 g/l and 65% yields from glucose in unsterilized media. Furthermore, ethanol titers and yields of 12 g/l and 50%, respectively, were produced from cellobiose and xylose in unsterilized seawater and algal-contaminated wastewater. As such, B. marmarensis presents a promising approach for the contamination-resistant biorefining of a wide range of carbohydrates in unsterilized, non-potable seawater.

  3. Extreme cosmos

    CERN Document Server

    Gaensler, Bryan

    2011-01-01

    The universe is all about extremes. Space has a temperature 270°C below freezing. Stars die in catastrophic supernova explosions a billion times brighter than the Sun. A black hole can generate 10 million trillion volts of electricity. And hypergiants are stars 2 billion kilometres across, larger than the orbit of Jupiter. Extreme Cosmos provides a stunning new view of the way the Universe works, seen through the lens of extremes: the fastest, hottest, heaviest, brightest, oldest, densest and even the loudest. This is an astronomy book that not only offers amazing facts and figures but also re

  4. Specific jarosite biomineralization by purpureocillium lilacinum, an acidophilic fungi isolated from río Tinto

    NARCIS (Netherlands)

    Oggerin, Monike; Tornos, Fernando; Rodríguez, Nuria; del Moral, C.; Sánchez-Román, M.; Amils, R.

    Río Tinto (Huelva, southwestern Spain) is an extreme environment with a remarkably constant acidic pH and a high concentration of heavy metals, conditions generated by the metabolic activity of chemolithotrophic microorganisms thriving in the rich complex sulfides of the Iberian Pyrite Belt (IPB).

  5. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  6. Microflora of urogenital tract in pregnancy with asymptomatic bacterium

    International Nuclear Information System (INIS)

    Abdullaeva, R.A.

    2006-01-01

    The article contains results of research interrelationship from colonization of vagina and urinary tract diseases. E.coli one of the main factors in development asymptomatic bacterium. Presented high effects of penicillin medicaments and nitrofurans in treatment of asymptomatic bacterium

  7. Engineering a wild fast-growing Mycoplasma bacterium to generate ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-12

    Jan 12, 2018 ... The CCPP bacterium causes sick animals to experience severe symptoms ... because antibiotic treatment does not eliminate the responsible bacterium. ... To develop a fast growing CCPP vaccine for cheaper production and ...

  8. Reduction of ferric iron by acidophilic heterotrophic bacteria: evidence for constitutive and inducible enzyme systems in Acidiphilium spp.

    Science.gov (United States)

    Johnson, D B; Bridge, T A M

    2002-01-01

    To compare the abilities of two obligately acidophilic heterotrophic bacteria, Acidiphilium acidophilum and Acidiphilium SJH, to reduce ferric iron to ferrous when grown under different culture conditions. Bacteria were grown in batch culture, under different aeration status, and in the presence of either ferrous or ferric iron. The specific rates of ferric iron reduction by fermenter-grown Acidiphilium SJH were unaffected by dissolved oxygen (DO) concentrations, while iron reduction by A. acidophilum was highly dependent on DO concentrations in the growth media. The ionic form of iron present (ferrous or ferric) had a minimal effect on the abilities of harvested cells to reduce ferric iron. Whole cell protein profiles of Acidiphilium SJH were very similar, regardless of the DO status of the growth medium, while additional proteins were present in A. acidophilum grown microaerobically compared with aerobically-grown cells. The dissimilatory reduction of ferric iron is constitutive in Acidiphilium SJH while it is inducible in A. acidophilum. Ferric iron reduction by Acidiphilium spp. may occur in oxygen-containing as well as anoxic acidic environments. This will detract from the effectiveness of bioremediation systems where removal of iron from polluted waters is mediated via oxidation and precipitation of the metal.

  9. A novel acidophilic, thermophilic iron and sulfur-oxidizing archaeon isolated from a hot spring of tengchong, yunnan, China

    Directory of Open Access Journals (Sweden)

    Jiannan Ding

    2011-06-01

    Full Text Available A novel thermoacidophilic iron and sulfur-oxidizing archaeon, strain YN25, was isolated from an in situ enriched acid hot spring sample collected in Yunnan, China. Cells were irregular cocci, about 0.9-1.02 µm×1.0-1.31 µm in the medium containing elemental sulfur and 1.5-2.22 µm×1.8-2.54 µm in ferrous sulfate medium. The ranges of growth and pH were 50-85 (optimum 65 and pH 1.0-6.0 (optimum 1.5-2.5. The acidophile was able to grow heterotrophically on several organic substrates, including various monosaccharides, alcohols and amino acids, though the growth on single substrate required yeast extract as growth factor. Growth occurred under aerobic conditions or via anaerobic respiration using elemental sulfur as terminal electron acceptor. Results of morphology, physiology, fatty acid analysis and analysis based on 16S rRNA gene sequence indicated that the strain YN25 should be grouped in the species Acidianus manzaensis. Bioleaching experiments indicated that this strain had excellent leaching capacity, with a copper yielding ratio up to 79.16% in 24 d. The type strain YN25 was deposited in China Center for Type Culture Collection (=CCTCCZNDX0050.

  10. Acquisition of useful and high ability genes for acidophilic bacteria; Kosansei saikin ni takai noryoku wo fuyosuru idenshi no kakutoku

    Energy Technology Data Exchange (ETDEWEB)

    Senda, T; Inoue, C; Shinbori, Y [Tohoku University, Sendai (Japan)

    1997-02-01

    This effort aims at the development of high-performance bacteria usable in bio-leaching in metal smelting by acquiring genes capable of realizing such. A method is used of choosing some isolated strains exhibiting high-performance traits and acquiring target genes therefrom by use of genetic engineering. Approximately 200 kinds in the aggregate of acidophilic bacteria are currently available for the study, including isolated iron-oxidizing and sulfur-oxidizing bacteria, standard species acquired for the study, and strains previously isolated by the laboratory. The bacteria are tested with respect to their Fe{sup 2+}-oxidizing rates, sulfur-oxidizing capabilities, and strength to withstand inhibiting substances (Ag{sup +}, Cl{sup -}, Mo{sup 6+}, etc.), which results in the nomination of 8 strains. The study planned to follow includes processes involving the extraction of chromosome DNAs from the 8 strains and their refinement, gene cloning by the Southern hybridization method, determination of their base sequences, determination of the difference between the strains in point of gene expression, and investigations of the relations that the results of these processes bear toward the said high-performance traits. Also under way is a study about the infuence-exerting factors revealed during the evaluation of the abilities of acidphlic bacteria. 2 refs., 2 tabs.

  11. Study of silver nanoparticles synthesized by acidophilic strain of Actinobacteria isolated from the of Picea sitchensis forest soil.

    Science.gov (United States)

    Railean-Plugaru, V; Pomastowski, P; Wypij, M; Szultka-Mlynska, M; Rafinska, K; Golinska, P; Dahm, H; Buszewski, B

    2016-05-01

    In the present work the acidophilic actinobacteria strain was used as a novel reducing agent for the cheap, green and single-step synthesis of nanostructure silver particles. Structural, morphological and optical properties of the synthesized nanoparticles have been characterized by spectroscopy, dynamic light scattering and electron microscopy approach. The antimicrobial activity of silver nanoparticles against clinical strains such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis and Salmonella infantis alone and in combination with antibiotics were studied. The crystalline and stable biosynthesized silver nanoparticles ranged in size from 4 to 45 nm and were mostly spherical in shape being characterized evolving several analytical techniques. The bioAgNPs inhibited growth of most bacterial strains. The highest antimicrobial activity was observed against Ps. aeruginosa (10 mm), followed by Staph. aureus, B. subtilis and Pr. mirabilis (all 8 mm). The lower activity was noticed for E. coli and Kl. pneumoniae (6 and 2 mm, respectively). Moreover, the synergistic effect of bio(AgNPs) with various commercially available antibiotics was also evaluated. The most significant results were observed for bio(AgNPs) combined with tetracycline, kanamycin, ampicillin and neomycin, followed by streptomycin and gentamycin against E. coli, Salm. infantis and Kl. pneumoniae. The most resistant bacteria to commercial antibiotics was Pr. mirabilis. The Streptacidiphilus sp. strain CGG11n isolated from acidic soil can be used to efficiently synthesize the bioactive nanoparticles using inexpensive substances in an eco-friendly and nontoxic manner. The present work provides helpful insight into the development of new antimicrobial agents with the synergistic enhancement of the antibacterial mechanism against pathogenic micro-organisms. The synthesized silver bionanoparticles from Streptacidiphilus sp. strain

  12. Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming.

    Science.gov (United States)

    Boyd, Eric S; King, Susan; Tomberlin, Jeffery K; Nordstrom, D Kirk; Krabbenhoft, David P; Barkay, Tamar; Geesey, Gill G

    2009-04-01

    Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH approximately 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg(+)), while undetectable or near the detection limit (0.025 ng l(-1)) in the source water of the springs, was present at concentrations of 4-7 ng g(-1) dry weight of mat biomass. Detection of MeHg(+) in tracheal tissue of larvae grazing the mat suggests that MeHg(+) enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg(+) was two to five times higher in larval tissue than mat biomass indicating MeHg(+) biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg(+) to species in the food web whose range extends beyond a particular geothermal feature of YNP.

  13. Complete genome sequence of Acidihalobacter prosperus strain F5, an extremely acidophilic, iron- and sulfur-oxidizing halophile with potential industrial applicability in saline water bioleaching of chalcopyrite.

    Science.gov (United States)

    Khaleque, Himel N; Corbett, Melissa K; Ramsay, Joshua P; Kaksonen, Anna H; Boxall, Naomi J; Watkin, Elizabeth L J

    2017-11-20

    Successful process development for the bioleaching of mineral ores, particularly the refractory copper sulfide ore chalcopyrite, remains a challenge in regions where freshwater is scarce and source water contains high concentrations of chloride ion. In this study, a pure isolate of Acidihalobacter prosperus strain F5 was characterized for its ability to leach base metals from sulfide ores (pyrite, chalcopyrite and pentlandite) at increasing chloride ion concentrations. F5 successfully released base metals from ores including pyrite and pentlandite at up to 30gL -1 chloride ion and chalcopyrite up to 18gL -1 chloride ion. In order to understand the genetic mechanisms of tolerance to high acid, saline and heavy metal stress the genome of F5 was sequenced and analysed. As well as being the first strain of Ac. prosperus to be isolated from Australia it is also the first complete genome of the Ac. prosperus species to be sequenced. The F5 genome contains genes involved in the biosynthesis of compatible solutes and genes encoding monovalent cation/proton antiporters and heavy metal transporters which could explain its abilities to tolerate high salinity, acidity and heavy metal stress. Genome analysis also confirmed the presence of genes involved in copper tolerance. The study demonstrates the potential biotechnological applicability of Ac. prosperus strain F5 for saline water bioleaching of mineral ores. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Acidithrix ferrooxidans gen. nov., sp. nov.; a filamentous and obligately heterotrophic, acidophilic member of the Actinobacteria that catalyzes dissimilatory oxido-reduction of iron.

    Science.gov (United States)

    Jones, Rose M; Johnson, D Barrie

    2015-01-01

    A novel acidophilic member of the phylum Actinobacteria was isolated from an acidic stream draining an abandoned copper mine in north Wales. The isolate (PY-F3) was demonstrated to be a heterotroph that catalyzed the oxidation of ferrous iron (but not of sulfur or hydrogen) under aerobic conditions, and the reduction of ferric iron under micro-aerobic and anaerobic conditions. PY-F3 formed long entangled filaments of cells (>50 μm long) during active growth phases, though these degenerated into smaller fragments and single cells in late stationary phase. Although isolate PY-F3 was not observed to grow below pH 2.0 and 10 °C, harvested biomass was found to oxidize ferrous iron at relatively fast rates at pH 1.5 and 5 °C. Phylogenetic analysis, based on comparisons of 16S rRNA gene sequences, showed that isolate PY-F3 has 91-93% gene similarity to those of the four classified genera and species of acidophilic Actinobacteria, and therefore is a representative of a novel genus. The binomial Acidithrix ferrooxidans is proposed for this new species, with PY-F3 as the designated type strain (=DSM 28176(T), =JCM 19728(T)). Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  15. Cloning, sequencing, and sequence analysis of two novel plasmids from the thermophilic anaerobic bacterium Anaerocellum thermophilum

    DEFF Research Database (Denmark)

    Clausen, Anders; Mikkelsen, Marie Just; Schrøder, I.

    2004-01-01

    The nucleotide sequence of two novel plasmids isolated from the extreme thermophilic anaerobic bacterium Anaerocellum thermophilum DSM6725 (A. thermophilum), growing optimally at 70degreesC, has been determined. pBAS2 was found to be a 3653 bp plasmid with a GC content of 43%, and the sequence re...... with highest similarity to DNA repair protein from Campylobacter jejuni (25% aa). Orf34 showed similarity to sigma factors with highest similarity (28% aa) to the sporulation specific Sigma factor, Sigma 28(K) from Bacillus thuringiensis....

  16. A Novel Uncultured Bacterium of the Family Gallionellaceae: Description and Genome Reconstruction Based on the Metagenomic Analysis of Microbial Community in Acid Mine Drainage.

    Science.gov (United States)

    Kadnikov, V V; Ivasenko, D A; Beletsky, A V; Mardanov, A V; Danilova, E V; Pimenov, N V; Karnachuk, O V; Ravin, N V

    2016-07-01

    Drainage waters at the metal mining areas often have low pH and high content of dissolved metals due to oxidation of sulfide minerals. Extreme conditions limit microbial diversity in- such ecosystems. A drainage water microbial community (6.5'C, pH 2.65) in an open pit at the Sherlovaya Gora polymetallic open-cast mine (Transbaikal region, Eastern Siberia, Russia) was studied using metagenomic techniques. Metagenome sequencing provided information for taxonomic and functional characterization of the micro- bial community. The majority of microorganisms belonged to a single uncultured lineage representing a new Betaproteobacteria species of the genus Gallionella. While no.acidophiles are known among the cultured members of the family Gallionellaceae, similar 16S rRNA gene sequences were detected in acid mine drain- ages. Bacteria ofthe genera Thiobacillus, Acidobacterium, Acidisphaera, and Acidithiobacillus,-which are com- mon in acid mine drainage environments, were the minor components of the community. Metagenomic data were -used to determine the almost complete (-3.4 Mb) composite genome of the new bacterial. lineage desig- nated Candidatus Gallionella acididurans ShG14-8. Genome analysis revealed that Fe(II) oxidation probably involved the cytochromes localized on the outer membrane of the cell. The electron transport chain included NADH dehydrogenase, a cytochrome bc1 complex, an alternative complex III, and cytochrome oxidases of the bd, cbb3, and bo3 types. Oxidation of reduced sulfur compounds probably involved the Sox system, sul- fide-quinone oxidoreductase, adenyl sulfate reductase, and sulfate adenyltransferase. The genes required for autotrophic carbon assimilation via the Calvin cycle were present, while no pathway for nitrogen fixation was revealed. High numbers of RND metal transporters and P type ATPases were probably responsible for resis- tance to heavy metals. The new microorganism was an aerobic chemolithoautotroph of the group of

  17. Multi-omics reveal the lifestyle of the acidophilic, mineral-oxidizing model species Leptospirillum ferriphilumT.

    Science.gov (United States)

    Christel, Stephan; Herold, Malte; Bellenberg, Sören; El Hajjami, Mohamed; Buetti-Dinh, Antoine; Pivkin, Igor V; Sand, Wolfgang; Wilmes, Paul; Poetsch, Ansgar; Dopson, Mark

    2017-11-17

    novel identification of genes for atmospheric nitrogen fixation, and represents an essential step for further accurate proteomic and transcriptomic investigation of this acidophile model species in the future. Additionally, light is shed on Leptospirillum ferriphilum T adaptation strategies to growth on the copper mineral chalcopyrite. This data can be applied to deepen our understanding and optimization of bioleaching and biooxidation, techniques that present sustainable and environmentally friendly alternatives to many traditional methods for metal extraction. Copyright © 2017 Christel et al.

  18. Characterization of the radioresistance in the radioresistant bacterium deinococcus radiodurans

    International Nuclear Information System (INIS)

    Kong Xiangrong; Du Zeji

    1999-01-01

    The radioresistance of wild type Deinococcus radiodurans KD8301 and the factors affecting the radioresistance were investigated. KH3111 which was a DNA repair mutant of KD8301 (Zeji Du, 1998) was used to be compared with KD8301. Deinococcus radiodurans was discovered by Anderson et al (1956) in X-ray sterilized canned meat that was found to have undergone spoilage. this bacterium and other species of this genus share extreme resistance to ionizing radiation and other agents that damage DNA. Wild type KD8301 and its sensitive mutant KH3111 were irradiated with 60 Co γ-ray at the dose range 0.5 ∼ 10 kGy. Dose-survival fraction curves were made and the radio resistances were determined by LD 99 . The relative contents of DNA in cells were measured by Fluorescence Spectrophotometry (Freedman and Bruce, 1971). The results indicated that wild type KD8301 possesses more radioresistant than its mutant KH3111, LD99 were 9.5 kGy and 2.4 kGy respectively. KD8301 grown at exponential phase showed a decreased resistance to radiation, and the LD99 was 5.1 kGy. No differences of DNA/protein in cells were found between the exponential phase and the stationary phase. The results could be concluded that wild type KD8301 possesses remarkable radioresistance, but this ability was decreased or disappeared after mutation (in KH3111). None DNA relative content other than the growth stages were determinant factors of radioresistance in Deinococcus radiodurans. This results were different from other report (Dickie N et al, 1990). The cellular mechanisms might be the deference's of the bacterium cell morphology between the exponential phase and the stationary phase. Recently, the mutation site of KH3111 which was mutated chemically from wild type KD8301 was identified (Zeji Du, 1998). One base pair changed in the novel gene pprA which was isolated from KD8301 genomic DNA. This point mutation was confirmed to be responsible for the sensitivity of KH3111 to γ-ray and other DNA

  19. DNA damage response in a radiation resistant bacterium Deinococcus radiodurans: a paradigm shift

    International Nuclear Information System (INIS)

    Misra, H.S.

    2015-01-01

    Deinococcusradiodurans is best known for its extraordinary resistance to gamma radiation with its D 10 12kGy, and several other DNA damaging agents including desiccation to less than 5% humidity and chemical xenotoxicants. An efficient DNA double strand break (DSB) repair and its ability to protect biomolecules from oxidative damage are a few mechanisms attributed to these phenotypes in this bacterium. Although it regulates its proteome and transcriptome in response to DNA damage for its growth and survival, it lacks LexA mediated classical SOS response mechanism. Since LexA mediated damages response mechanism is highly and perhaps only, characterized DNA damage response processes in prokaryotes, this bacterium keeps us guessing how it responds to extreme doses of DNA damage. Interestingly, this bacterium encodes a large number of eukaryotic type serine threonine/tyrosine protein kinases (eST/YPK), phosphatases and response regulators and roles of eST/YPKs in cellular response to DNA damage and cell cycle regulations are well established in eukaryotes. Here, we characterized an antioxidant and DNA damage inducible eST/YPK (RqkA) and established its role in extraordinary radioresistance and DSB repair in this bacterium. We identified native phosphoprotein substrates for this kinase and demonstrated the involvement of some of these proteins phosphorylation in the regulation of DSB repair and growth under radiation stress. Findings suggesting the possible existence of eST/YPK mediated DNA damage response mechanism as an alternate to classical SOS response in this prokaryote would be discussed. (author)

  20. Agrobacterium tumefaciens is a diazotrophic bacterium

    International Nuclear Information System (INIS)

    Kanvinde, L.; Sastry, G.R.K.

    1990-01-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate 15 N supplied as 15 N 2 . As with most other well-characterized diazotrophic bacteria, the presence of NH 4 + in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship

  1. Agrobacterium tumefaciens is a diazotrophic bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Kanvinde, L.; Sastry, G.R.K. (Univ. of Leeds (England))

    1990-07-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate {sup 15}N supplied as {sup 15}N{sub 2}. As with most other well-characterized diazotrophic bacteria, the presence of NH{sub 4}{sup +} in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship.

  2. The chemical formula of a magnetotactic bacterium.

    Science.gov (United States)

    Naresh, Mohit; Das, Sayoni; Mishra, Prashant; Mittal, Aditya

    2012-05-01

    Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio-derived products by regulating intra-cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as CH(2.06)O(0.13)N(0.28)Fe(1.74×10(-3)). Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life. Copyright © 2011 Wiley Periodicals, Inc.

  3. Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

    Directory of Open Access Journals (Sweden)

    Nieto Pamela A

    2008-11-01

    uptake systems could reflect their obligatory occupation of extremely low pH environments where high concentrations of soluble iron may always be available and were oxidized sulfur species might not compromise iron speciation dynamics. Presence of bacterioferritin in the Acidithiobacilli, polyphosphate accumulation functions and variants of FieF-like diffusion facilitators in both Acidithiobacilli and Leptospirilla, indicate that they may remove or store iron under conditions of variable availability. In addition, the Fe(II-oxidizing capacity of both A. ferrooxidans and Leptospirilla could itself be a way to evade iron stress imposed by readily available Fe(II ions at low pH. Fur regulatory sites have been predicted for a number of gene clusters including iron related and non-iron related functions in both the Acidithiobacilli and Leptospirilla, laying the foundation for the future discovery of iron regulated and iron-phosphate coordinated regulatory control circuits. Conclusion In silico analyses of the genomes of acidophilic bacteria are beginning to tease apart the mechanisms that mediate iron uptake and homeostasis in low pH environments. Initial models pinpoint significant differences in abundance and diversity of iron management mechanisms between Leptospirilla and Acidithiobacilli, and begin to reveal how these two groups respond to iron cycling and iron fluctuations in naturally acidic environments and in industrial operations. Niche partitions and ecological successions between acidophilic microorganisms may be partially explained by these observed differences. Models derived from these analyses pave the way for improved hypothesis testing and well directed experimental investigation. In addition, aspects of these models should challenge investigators to evaluate alternative iron management strategies in non-acidophilic model organisms.

  4. Acidophilic sulfur disproportionation

    Science.gov (United States)

    Hardisty, Dalton S.; Olyphant, Greg A.; Bell, Jonathan B.; Johnson, Adam P.; Pratt, Lisa M.

    2013-07-01

    Bacterial disproportionation of elemental sulfur (S0) is a well-studied metabolism and is not previously reported to occur at pH values less than 4.5. In this study, a sediment core from an abandoned-coal-mine-waste deposit in Southwest Indiana revealed sulfur isotope fractionations between S0 and pyrite (Δ34Ses-py) of up to -35‰, inferred to indicate intense recycling of S0 via bacterial disproportionation and sulfide oxidation. Additionally, the chemistry of seasonally collected pore-water profiles were found to vary, with pore-water pH ranging from 2.2 to 3.8 and observed seasonal redox shifts expressed as abrupt transitions from Fe(III) to Fe(II) dominated conditions, often controlled by fluctuating water table depths. S0 is a common product during the oxidation of pyrite, a process known to generate acidic waters during weathering and production of acid mine drainage. The H2S product of S0 disproportionation, fractionated by up to -8.6‰, is rapidly oxidized to S0 near redox gradients via reaction with Fe(III) allowing for the accumulation of isotopically light S0 that can then become subject to further sulfur disproportionation. A mass-balance model for S0 incorporating pyrite oxidation, S0 disproportionation, and S0 oxidation readily explains the range of observed Δ34Ses-py and emphasizes the necessity of seasonally varying pyrite weathering and metabolic rates, as indicated by the pore water chemistry. The findings of this research suggest that S0 disproportionation is potentially a common microbial process at a pH < 4.5 and can create large sulfur isotope fractionations, even in the absence of sulfate reduction.

  5. Specificity of pH sensitive Tc(V)-DMS for acidophilic osteoclastic bone cells: biological and cellular studies

    International Nuclear Information System (INIS)

    Horiuchi, K.; Konno, A.; Nishio, S.; Fukuda, Y.; Saji, H.; Hashimoto, K.

    2002-01-01

    Bone scintigraphy is a sensitive imaging method for detecting skeletal metastases but the low specificity has decreased its oncological use. Bone scintigraphy has relied on Tc-bisphosphonate (Tc-BP) agents with affinity for the mineral phase. However, bio-functional Tc(V)-DMS agent, sensitive to acid pH of tumoral tissue has shown osteotrophic properties, in adult bone pathologies. Objectives: Basis for understanding the osteotropic character of the pH sensitive Tc(V)-DMS in bone metastasis. Methods: Studies on differential Tc(V)-DMS and Tc-BP accumulation response were carried out by acidophilic osteoclast (OC) and basophilic osteoblast (OB) cells subjected to variable pH incubation media (HEPES, 37 0 C) and by bone tissue of Ehrlich Ascites Tumor (EAT) bearing mice, exposed to systemic NH4Cl or glucose mediated acidification (GmAc). Agents injected into tail vein and bone radioactivity analyzed. Bone metabolism markers measured in blood and urine (pH, Pi, Ca , Alp, Dpd). Acid-base regulation effect at cellular level, analyzed by using bafilomycin, amiloride, DIDS and acetazolamide inhibitors. Results: Lack of any OB response to acidification or alkalinization detected with either Tc(V)-DMS or Tc-BP agent. However, OC cells were highly sensitivity to acidification only in the presence of Tc(V)-DMS showing great radioactivity increase as the pH was lowered. This specificity also detected, in EAT bearing mice; increased bone tissue accumulation in response to systemic acidification was clearly detected upon administration of Tc(V)-DMS only under GmAc, an experimental model showing high urine excretion of deoxypyridinoline, a bone resorption marker. Conclusion: Peculiarity of multi nucleated OC cells sensitive to the environment pH and their activation in acid pH has been well known. Tc-BP agent showed lack of affinity for OC or OB cells. Specific affinity of OC cells for Tc(V)-DMS and its increased bone accumulation with the systemic pH lowering reflect the p

  6. Characterization of bacteria acidophilic in samples of water coming into a region that suffers influence of uranium mine in Caldas (MG)

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Michelle B.; Ferrari, Carla R.; Roque, Claudio V.; Ronqui, Leilane B.; Nascimento, Marcos R.L. do; Rodgher, Suzelei; Azevedo, Heliana [Laboratorio de Pocos de Caldas (LAPOC-CNEN/MG), MG (Brazil)], e-mail: michelle_borato@hotmail.com, e-mail: carlarolimferrari@yahoo.com.br, e-mail: cvroque@cnen.gov.br, e-mail: leilanebio@yahoo.com.br, e-mail: pmarcos@cnen.gov.br, e-mail: surodgher@uol.com.br, e-mail: hgomes@cnen.gov.br

    2009-07-01

    The fundamental condition for the bioleaching of the uranium ore is the presence of metallic sulfide such as pyrite associated with the ore, which is found in the ore and in the waste at the Unidade de Tratamento de Minerio (UTM) of Pocos de Caldas, State of Minas Gerais, Brazil. The present study aims to determine the chemical and microbiological characteristics in effluents of uranium mining from the UTM and in Antas dam, which receives treated effluents from the UTM. Water samples were collected Pit Mine (CM), located within the UTM facilities and from site 41 (Antas dam) in July and October 2008. We verified low pH values in water samples from CM (3.7) in comparison to the ones found at site 41 (6.65). There was a higher medium density value of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and heterotrophic acidophilic bacteria in water samples at site CM compared to the values recorded from samples at site 41. Medium values of Fe{sup 2+}, uranium and zinc in samples from the site CM were higher than at site 41. The concentration of fluoride (68.5 mL{sup -l}) and manganese (2.34 mL{sup -1}) in water samples from site 41 were above the limits fixed for water bodies in Resolution CONAMA 357. The relative seasonal variation of some variables observed at site CM (low pH values, high densities of Acidithiobacillus sp. and heterotrophic acidophilic bacteria) shows that this site is one of the main sites of occurrence of acid mine drainage and action of bioleaching bacteria at UTM. (author)

  7. Characterization of bacteria acidophilic in samples of water coming into a region that suffers influence of uranium mine in Caldas (MG)

    International Nuclear Information System (INIS)

    Campos, Michelle B.; Ferrari, Carla R.; Roque, Claudio V.; Ronqui, Leilane B.; Nascimento, Marcos R.L. do; Rodgher, Suzelei; Azevedo, Heliana

    2009-01-01

    The fundamental condition for the bioleaching of the uranium ore is the presence of metallic sulfide such as pyrite associated with the ore, which is found in the ore and in the waste at the Unidade de Tratamento de Minerio (UTM) of Pocos de Caldas, State of Minas Gerais, Brazil. The present study aims to determine the chemical and microbiological characteristics in effluents of uranium mining from the UTM and in Antas dam, which receives treated effluents from the UTM. Water samples were collected Pit Mine (CM), located within the UTM facilities and from site 41 (Antas dam) in July and October 2008. We verified low pH values in water samples from CM (3.7) in comparison to the ones found at site 41 (6.65). There was a higher medium density value of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and heterotrophic acidophilic bacteria in water samples at site CM compared to the values recorded from samples at site 41. Medium values of Fe 2+ , uranium and zinc in samples from the site CM were higher than at site 41. The concentration of fluoride (68.5 mL -l ) and manganese (2.34 mL -1 ) in water samples from site 41 were above the limits fixed for water bodies in Resolution CONAMA 357. The relative seasonal variation of some variables observed at site CM (low pH values, high densities of Acidithiobacillus sp. and heterotrophic acidophilic bacteria) shows that this site is one of the main sites of occurrence of acid mine drainage and action of bioleaching bacteria at UTM. (author)

  8. Three new genera of fungi from extremely acidic soils

    Czech Academy of Sciences Publication Activity Database

    Hujslová, Martina; Kubátová, A.; Kostovčík, Martin; Blanchette, R.A.; de Beer, Z.W.; Chudíčková, Milada; Kolařík, Miroslav

    2014-01-01

    Roč. 13, č. 3 (2014), s. 819-831 ISSN 1617-416X Institutional support: RVO:61388971 Keywords : Amplistromataceae * Micromycetes * Acidophilic Subject RIV: EE - Microbiology, Virology Impact factor: 1.913, year: 2014

  9. Genomics and transcriptomics of the hydrogen producing extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus

    NARCIS (Netherlands)

    Verhaart, M.R.A.

    2010-01-01

    As fossil fuels are depleting, there is a clear need for alternative sustainable fuel sources. One of the interesting alternatives is hydrogen, which can be produced from biomass by bacteria and archaea. To make the application feasible, organisms are needed which have high hydrogen productivities

  10. Ethanologenic potential of the bacterium Bacillus cereus NB-19 in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-01

    Dec 1, 2009 ... Ethanologenic bacterium was cultivated in a suspension of sugarcane ... bagasse is very useful for obtaining yields of the different products including cell mass and ethanol as ... the resources for the green fuel generation.

  11. Extremely Preterm Birth

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Extremely Preterm Birth Home For Patients Search FAQs Extremely Preterm Birth ... Spanish FAQ173, June 2016 PDF Format Extremely Preterm Birth Pregnancy When is a baby considered “preterm” or “ ...

  12. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  13. [Genetic variability of the bacterium Ralstonia solanacearum (Burkholderiales: Burholderiaceae) in the banana-growing region of Uraba (Colombia)].

    Science.gov (United States)

    Cardozo, Carolina; Rodríguez, Paola; Cotes, José Miguel; Marín, Mauricio

    2010-03-01

    The banana moko disease, caused by the bacterium Ralstonia solanacearum, is one of the most important phytopathological problems of the banana agribusiness in tropical countries. In Uraba and Magdalena (Colombia), the main exporting regions of banana in Colombia, this disease causes a destruction estimated in 16.5 ha/year. The bacterium presents an extremely high level of genetic variation that affects control measures. This is the first study of its variation in Colombia and was done with AFLP molecular markers on a population of 100 isolates from banana plants, soils and "weeds". The high level of genetic diversity, with Nei and Shannon indexes of h=0.32 and I=0.48, respectively, and the AMOVA, showed that this population is subestructured (Fst=0.66): the host is the main factor of differentiation. Even so, previous tests show that all varieties have pathogenicity on Musa.

  14. Isolation and characterization of a novel agarase-producing Pseudoalteromonas spp. bacterium from the guts of spiny turban shells.

    Science.gov (United States)

    Oh, Young Hoon; Jung, Changkyou; Lee, Jinwon

    2011-08-01

    An agar-degrading bacterium was isolated from the guts of spiny turban shells. It was identified as a Pseudoalteromonas species and named Pseudoalteromonas sp. JYBCL 1. The viscosity of the inoculated agar medium decreased by more than 60% after 20 h cultivation. The agarase produced by the isolate had optimal activities at 35 degrees C and pH 7. The enzyme had extremely strong resistance to ionic stress compared with other known agarases. Its molecular mass was estimated at about 60 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The agarase could saccharify Gelidium amansii directly, with an efficiency about half that compared with agar saccharification.

  15. Enhancement of anaerobic acidogenesis by integrating an electrochemical system into an acidogenic reactor: effect of hydraulic retention times (HRT) and role of bacteria and acidophilic methanogenic Archaea.

    Science.gov (United States)

    Zhang, Jingxin; Zhang, Yaobin; Quan, Xie; Chen, Shuo

    2015-03-01

    In this study, an acidogenic reactor packed with a pair of Fe-carbon electrodes (R1) was developed to enhance anaerobic acidogenesis of organic wastewater at short hydraulic retention times. The results indicated that the acidogenic efficiency was improved by settling a bio-electrochemical system. When hydraulic retention times decreased from 12 to 3h, R1 showed 18.9% more chemical oxygen demand removal and 13.8% more acidification efficiency. After cutting off the voltage of R1, the COD removal decreased by about 5%. Coupling of Fe(2+) leaching and electric field accelerated the hydrolysis of polysaccharide, relieving its accumulation in the sludge phase. Several acidophilic methanogenic Archaea such as Methanosarcina sp. were enriched in R1, which was favorable for consuming organic acids and preventing excessive pH decline. Thus, the developed acidogenic reactor with Fe-carbon electrodes is expected to be potentially effective and useful for wastewater treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2009-01-01

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

  17. Application of a mixed culture of adapted acidophilic bacteria in two-step bioleaching of spent lithium-ion laptop batteries

    Science.gov (United States)

    Heydarian, Ahmad; Mousavi, Seyyed Mohammad; Vakilchap, Farzane; Baniasadi, Mahsa

    2018-02-01

    The rapid increase in the production of electrical and electronic equipment, along with higher consumption of these products, has caused defective and obsolete equipment to accumulate in the environment. In this research, bioleaching of spent lithium-ion batteries (LIBs) used in laptops is carried out under two-step condition based on the bacterial activities of a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. First, the best inoculum ratio of two acidophilic bacteria for the mixed culture is obtained. Next, adaptation is carried out successfully and the solid-to-liquid ratio reaches 40 g L-1. Response surface methodology is utilized to optimize the effective variables of initial pH, iron sulfate and sulfur concentrations. The maximum recovery of metal is about 99.2% for Li, 50.4% for Co and 89.4% for Ni under optimum conditions of 36.7 g L-1 iron sulfate concentration, 5.0 g L-1 sulfur concentration and initial pH of 1.5 for the best inoculum ratio of 3/2. Results of FE-SEM, XRD and FTIR analysis before and after bioleaching confirm that bacterial activity is a promising and effective route for metal recovery from spent LIBs. Toxicity assessment tests demonstrate the suitability of the bioleached residual as a nonhazardous material that meets environmental limitations for safe disposal.

  18. Genomic insights into a new acidophilic, copper-resistant Desulfosporosinus isolate from the oxidized tailings area of an abandoned gold mine.

    Science.gov (United States)

    Mardanov, Andrey V; Panova, Inna A; Beletsky, Alexey V; Avakyan, Marat R; Kadnikov, Vitaly V; Antsiferov, Dmitry V; Banks, David; Frank, Yulia A; Pimenov, Nikolay V; Ravin, Nikolai V; Karnachuk, Olga V

    2016-08-01

    Microbial sulfate reduction in acid mine drainage is still considered to be confined to anoxic conditions, although several reports have shown that sulfate-reducing bacteria occur under microaerophilic or aerobic conditions. We have measured sulfate reduction rates of up to 60 nmol S cm(-3) day(-1) in oxidized layers of gold mine tailings in Kuzbass (SW Siberia). A novel, acidophilic, copper-tolerant Desulfosporosinus sp. I2 was isolated from the same sample and its genome was sequenced. The genomic analysis and physiological data indicate the involvement of transporters and additional mechanisms to tolerate metals, such as sequestration by polyphosphates. Desulfosporinus sp. I2 encodes systems for a metabolically versatile life style. The genome possessed a complete Embden-Meyerhof pathway for glycolysis and gluconeogenesis. Complete oxidation of organic substrates could be enabled by the complete TCA cycle. Genomic analysis found all major components of the electron transfer chain necessary for energy generation via oxidative phosphorylation. Autotrophic CO2 fixation could be performed through the Wood-Ljungdahl pathway. Multiple oxygen detoxification systems were identified in the genome. Taking into account the metabolic activity and genomic analysis, the traits of the novel isolate broaden our understanding of active sulfate reduction and associated metabolism beyond strictly anaerobic niches. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  20. Extreme value distributions

    CERN Document Server

    Ahsanullah, Mohammad

    2016-01-01

    The aim of the book is to give a through account of the basic theory of extreme value distributions. The book cover a wide range of materials available to date. The central ideas and results of extreme value distributions are presented. The book rwill be useful o applied statisticians as well statisticians interrested to work in the area of extreme value distributions.vmonograph presents the central ideas and results of extreme value distributions.The monograph gives self-contained of theory and applications of extreme value distributions.

  1. Antagonistic bioactivity of an endophytic bacterium isolated from ...

    African Journals Online (AJOL)

    Antagonistic bioactivity of an endophytic bacterium isolated from Epimedium brevicornu Maxim. R He, G Wang, X Liu, C Zhang, F Lin. Abstract. Endophytic bacteria are one of the most potential biological control agents in plant disease protection. The aim of this work was to evaluate the antimicrobial activities of a strain of ...

  2. The physiology of the filamentous bacterium Microthrix parvicella

    NARCIS (Netherlands)

    Slijkhuis, H.

    1983-01-01

    A study has been made of the physiology of Microthrix parvicella. This filamentous bacterium often causes poor settleability of activated sludge in oxidation ditches supplied with domestic sewage. The organism was found to utilize only long chain fatty acids (preferably in

  3. The Bacterium That Got Infected by a Cow! - Horizontal Gene

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 1. The Bacterium That Got Infected by a Cow! - Horizontal Gene Transfer and Evolution. Saurabh Dhawan Tomás John Ryan. General Article Volume 12 Issue 1 January 2007 pp 49-59 ...

  4. Monitoring of a novel bacterium, Lactobacillus thermotolerans , in ...

    African Journals Online (AJOL)

    Abstract. We successfully established fluorescence in situ hybridization (FISH) method for specific detection and enumeration of a novel bacterium, Lactobacillus thermotolerans, in chicken feces. The specific FISH probes were designed based on the L. thermotolerans 16S rRNA gene sequences, and these sequences were ...

  5. methoxyethanol by a new bacterium isolate Pseudomonas sp. Strain

    African Journals Online (AJOL)

    Michael Horsfall

    A 2-methoxyethanol degrading bacterium was isolated from anaerobic sludge of a municipal sewage from ... Stoichiometrically, the strain utilized one mole of oxygen per one mole of 2-methoxyethanol instead of ... physiological and biochemical characterization of the .... observed with acetate and the intact resting cells.

  6. Non-obligate predatory bacterium burkholderia casidaeand uses thereof

    OpenAIRE

    1998-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  7. Non-obligate predatory bacterium Burkholderia casidae and uses thereof

    OpenAIRE

    2001-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  8. 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.

  9. Microbial activity in an acid resin deposit: Biodegradation potential and ecotoxicology in an extremely acidic hydrocarbon contamination

    International Nuclear Information System (INIS)

    Kloos, Karin; Schloter, Michael; Meyer, Ortwin

    2006-01-01

    Acid resins are residues produced in a recycling process for used oils that was in use in the forties and fifties of the last century. The resin-like material is highly contaminated with mineral oil hydrocarbons, extremely acidic and co-contaminated with substituted and aromatic hydrocarbons, and heavy metals. To determine the potential for microbial biodegradation the acid resin deposit and its surroundings were screened for microbial activity by soil respiration measurements. No microbial activity was found in the core deposit. However, biodegradation of hydrocarbons was possible in zones with a lower degree of contamination surrounding the deposit. An extreme acidophilic microbial community was detected close to the core deposit. With a simple ecotoxicological approach it could be shown that the pure acid resin that formed the major part of the core deposit, was toxic to the indigenous microflora due to its extremely low pH of 0-1. - Acidity is the major toxic factor of the extremely hydrophobic and acidic mixed contamination found in an acid resin deposit

  10. Going from Microbial Ecology to Genome Data and Back: Studies on a Haloalkaliphilic Bacterium Isolated from Soap Lake, Washington State

    Directory of Open Access Journals (Sweden)

    Melanie R. Mormile

    2014-11-01

    Full Text Available Soap Lake is a meromictic, alkaline (~pH 9.8 and saline (~14 to 140 g liter-1 lake located in the semiarid area of eastern Washington State. Of note is the length of time it has been meromictic (at least 2000 years and the extremely high sulfide level (~140 mM in its monimolimnion. As expected, the microbial ecology of this lake is greatly influenced by these conditions. A bacterium, Halanaerobium hydrogeniformans, was isolated from the mixolimnion region of this lake. H. hydrogeniformans is a haloalkaliphilic bacterium capable of forming hydrogen from 5- and 6-carbon sugars derived from hemicellulose and cellulose. Due to its ability to produce hydrogen under saline and alkaline conditions, in amounts that rival genetically modified organisms, its genome was sequenced. This sequence data provides an opportunity to explore the unique metabolic capabilities of this organism, including the mechanisms for tolerating the extreme conditions of both high salinity and alkalinity of its environment.

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

    Directory of Open Access Journals (Sweden)

    Esparza Mario

    2010-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Sigde Mamani

    2016-09-01

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

  13. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity.

    Science.gov (United States)

    Urbieta, María Sofía; Porati, Graciana Willis; Segretín, Ana Belén; González-Toril, Elena; Giaveno, María Alejandra; Donati, Edgardo Rubén

    2015-07-08

    The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  14. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity

    Directory of Open Access Journals (Sweden)

    María Sofía Urbieta

    2015-07-01

    Full Text Available The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  15. How extreme is extreme hourly precipitation?

    Science.gov (United States)

    Papalexiou, Simon Michael; Dialynas, Yannis G.; Pappas, Christoforos

    2016-04-01

    The importance of accurate representation of precipitation at fine time scales (e.g., hourly), directly associated with flash flood events, is crucial in hydrological design and prediction. The upper part of a probability distribution, known as the distribution tail, determines the behavior of extreme events. In general, and loosely speaking, tails can be categorized in two families: the subexponential and the hyperexponential family, with the first generating more intense and more frequent extremes compared to the latter. In past studies, the focus has been mainly on daily precipitation, with the Gamma distribution being the most popular model. Here, we investigate the behaviour of tails of hourly precipitation by comparing the upper part of empirical distributions of thousands of records with three general types of tails corresponding to the Pareto, Lognormal, and Weibull distributions. Specifically, we use thousands of hourly rainfall records from all over the USA. The analysis indicates that heavier-tailed distributions describe better the observed hourly rainfall extremes in comparison to lighter tails. Traditional representations of the marginal distribution of hourly rainfall may significantly deviate from observed behaviours of extremes, with direct implications on hydroclimatic variables modelling and engineering design.

  16. Optimization with Extremal Dynamics

    International Nuclear Information System (INIS)

    Boettcher, Stefan; Percus, Allon G.

    2001-01-01

    We explore a new general-purpose heuristic for finding high-quality solutions to hard discrete optimization problems. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. Extremal optimization successively updates extremely undesirable variables of a single suboptimal solution, assigning them new, random values. Large fluctuations ensue, efficiently exploring many local optima. We use extremal optimization to elucidate the phase transition in the 3-coloring problem, and we provide independent confirmation of previously reported extrapolations for the ground-state energy of ±J spin glasses in d=3 and 4

  17. Curiously modern DNA for a "250 million-year-old" bacterium.

    Science.gov (United States)

    Nickle, David C; Learn, Gerald H; Rain, Matthew W; Mullins, James I; Mittler, John E

    2002-01-01

    Studies of ancient DNA have attracted considerable attention in scientific journals and the popular press. Several of the more extreme claims for ancient DNA have been questioned on biochemical grounds (i.e., DNA surviving longer than expected) and evolutionary grounds (i.e., nucleotide substitution patterns not matching theoretical expectations for ancient DNA). A recent letter to Nature from Vreeland et al. (2000), however, tops all others with respect to age and condition of the specimen. These researchers extracted and cultured a bacterium from an inclusion body from what they claim is a 250 million-year (Myr)-old salt crystal. If substantiated, this observation could fundamentally alter views about bacterial physiology, ecology and evolution. Here we report on molecular evolutionary analyses of the 16S rDNA from this specimen. We find that 2-9-3 differs from a modern halophile, Salibacillus marismortui, by just 3 unambiguous bp in 16S rDNA, versus the approximately 59 bp that would be expected if these bacteria evolved at the same rate as other bacteria. We show, using a Poisson distribution, that unless it can be shown that S. marismortui evolves 5 to 10 times more slowly than other bacteria for which 16S rDNA substitution rates have been established, Vreeland et al.'s claim would be rejected at the 0.05 level. Also, a molecular clock test and a relative rates test fail to substantiate Vreeland et al.'s claim that strain 2-9-3 is a 250-Myr-old bacterium. The report of Vreeland et al. thus falls into a long series of suspect ancient DNA studies.

  18. Extracellular polymer substance synthesized by a halophilic bacterium Chromohalobacter canadensis 28.

    Science.gov (United States)

    Radchenkova, Nadja; Boyadzhieva, Ivanka; Atanasova, Nikolina; Poli, Annarita; Finore, Ilaria; Di Donato, Paola; Nicolaus, Barbara; Panchev, Ivan; Kuncheva, Margarita; Kambourova, Margarita

    2018-04-03

    Halophilic microorganisms are producers of a lot of new compounds whose properties suggest promising perspectives for their biotechnological exploration. Moderate halophilic bacterium Chromohalobacter canadensis 28 was isolated from Pomorie salterns as an extracellular polymer substance (EP) producer. The best carbon source for extracellular polymer production was found to be lactose, a sugar received as a by-product from the dairy industry. After optimization of the culture medium and physicochemical conditions for cultivation, polymer biosynthesis increased more than 2-fold. The highest level of extracellular polymer synthesis by C. canadensis 28 was observed in an unusually high NaCl concentration (15% w/v). Chemical analysis of the purified polymer revealed the presence of an exopolysaccharide (EPS) fraction (14.3% w/w) and protein fraction (72% w/w). HPLC analysis of the protein fraction showed the main presence of polyglutamic acid (PGA) (75.7% w/w). EPS fraction analysis revealed the following sugar composition (% w/w): glucosamine 36.7, glucose 32.3, rhamnose 25.4, xylose 1.7, and not identified sugar 3.9. The hydrogel formed by PGA and EPS fractions showed high swelling behavior, very good emulsifying and stabilizing properties, and good foaming ability. This is the first report for halophilic bacterium able to synthesize a polymer containing PGA fraction. The synthesized biopolymer shows an extremely high hydrophilicity, due to the simultaneous presence of PGA and EPS. The analysis of its functional properties and the presence of glucosamine in the highest proportion in EPS fraction clearly determine the potential of EP synthesized by C. canadensis 28 for application in the cosmetics industry.

  19. Osmoregulation in the Halophilic Bacterium Halomonas elongata: A Case Study for Integrative Systems Biology.

    Science.gov (United States)

    Kindzierski, Viktoria; Raschke, Silvia; Knabe, Nicole; Siedler, Frank; Scheffer, Beatrix; Pflüger-Grau, Katharina; Pfeiffer, Friedhelm; Oesterhelt, Dieter; Marin-Sanguino, Alberto; Kunte, Hans-Jörg

    2017-01-01

    Halophilic bacteria use a variety of osmoregulatory methods, such as the accumulation of one or more compatible solutes. The wide diversity of compounds that can act as compatible solute complicates the task of understanding the different strategies that halophilic bacteria use to cope with salt. This is specially challenging when attempting to go beyond the pathway that produces a certain compatible solute towards an understanding of how the metabolic network as a whole addresses the problem. Metabolic reconstruction based on genomic data together with Flux Balance Analysis (FBA) is a promising tool to gain insight into this problem. However, as more of these reconstructions become available, it becomes clear that processes predicted by genome annotation may not reflect the processes that are active in vivo. As a case in point, E. coli is unable to grow aerobically on citrate in spite of having all the necessary genes to do it. It has also been shown that the realization of this genetic potential into an actual capability to metabolize citrate is an extremely unlikely event under normal evolutionary conditions. Moreover, many marine bacteria seem to have the same pathways to metabolize glucose but each species uses a different one. In this work, a metabolic network inferred from genomic annotation of the halophilic bacterium Halomonas elongata and proteomic profiling experiments are used as a starting point to motivate targeted experiments in order to find out some of the defining features of the osmoregulatory strategies of this bacterium. This new information is then used to refine the network in order to describe the actual capabilities of H. elongata, rather than its genetic potential.

  20. Serpentine endophytic bacterium Pseudomonas azotoformans ASS1 accelerates phytoremediation of soil metals under drought stress.

    Science.gov (United States)

    Ma, Ying; Rajkumar, Mani; Moreno, António; Zhang, Chang; Freitas, Helena

    2017-10-01

    This study evaluates the potential of serpentine endophytic bacterium to foster phytoremediation efficiency of Trifolium arvense grown on multi-metal (Cu, Zn and Ni) contaminated soils under drought stress. A drought resistant endophytic bacterial strain ASS1 isolated from the leaves of Alyssum serpyllifolium grown in serpentine soils was identified as Pseudomonas azotoformans based on biochemical tests and partial 16S rRNA gene sequencing. P. azotoformans ASS1 possessed abiotic stress resistance (heavy metals, drought, salinity, antibiotics and extreme temperature) and plant growth promoting (PGP) properties (phosphate solubilization, nitrogen fixation, production of 1-aminocyclopropane-1-carboxylate deaminase, siderophore and ammonia). Inoculation of T. arvense with ASS1 considerably increased the plant biomass and leaf relative water content in both roll towel assay and pot experiments in the absence and presence of drought stress (DS). In the pot experiments, ASS1 greatly enhanced chlorophyll content, catalase, peroxidase, superoxide dismutase activities, and proline content (only in the absence of drought) in plant leaves, whereas they decreased the concentrations of malondialdehyde. Irrespective of water stress, ASS1 significantly improved accumulation, total removal, bio-concentration factor and biological accumulation coefficient of metals (Cu, Zn and Ni), while decreased translocation factors of Cu. The effective colonization and survival in the rhizosphere and tissue interior assured improved plant growth and successful metal phytoremediation under DS. These results demonstrate the potential of serpentine endophytic bacterium ASS1 for protecting plants against abiotic stresses and helping plants to thrive in semiarid ecosystems and accelerate phytoremediation process in metal polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Classifying Returns as Extreme

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2014-01-01

    I consider extreme returns for the stock and bond markets of 14 EU countries using two classification schemes: One, the univariate classification scheme from the previous literature that classifies extreme returns for each market separately, and two, a novel multivariate classification scheme tha...

  2. Biosorption of heavy metals by a marine bacterium

    International Nuclear Information System (INIS)

    Iyer, Anita; Mody, Kalpana; Jha, Bhavanath

    2005-01-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here

  3. Biosorption of heavy metals by a marine bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Anita [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India); Mody, Kalpana [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)]. E-mail: khmody@csmcri.org; Jha, Bhavanath [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2005-03-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here.

  4. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    OpenAIRE

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and c...

  5. Antibacterial marine bacterium deter luminous vibriosis in shrimp larvae

    OpenAIRE

    Abraham, T.J.

    2004-01-01

    Inhibitory activity of a marine pigmented bacterium - Alteromonas sp. - isolated from Penaeus monodon Fabricius larva against pathogenic and environmental isolates of Vibrio harveyi was studied. All the isolates were inhibited to varying degrees by Alteromonas sp. in vitro. The antibacterial substance produced by the Alteromonas sp. was soluble in organic solvent and closely bound to the external surface of bacterial cells. The antibacterial Alteromonas sp., when allowed to colonize on shrimp...

  6. Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

    Directory of Open Access Journals (Sweden)

    Lukasz Makowski

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

  7. MODELING OF MIXED CHEMOSTAT CULTURES OF AN AEROBIC BACTERIUM, COMAMONAS-TESTOSTERONI, AND AN ANAEROBIC BACTERIUM, VEILLONELLA-ALCALESCENS - COMPARISON WITH EXPERIMENTAL-DATA

    NARCIS (Netherlands)

    GERRITSE, J; SCHUT, F; GOTTSCHAL, JC

    A mathematical model of mixed chemostat cultures of the obligately aerobic bacterium Comamonas testosteroni and the anaerobic bacterium Veillonella alcalescens grown under dual limitation Of L-lactate and oxygen was constructed. The model was based on Michaelis-Menten-type kinetics for the

  8. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    NARCIS (Netherlands)

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a

  9. Extremal surface barriers

    International Nuclear Information System (INIS)

    Engelhardt, Netta; Wall, Aron C.

    2014-01-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

  10. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.; Huser, Raphaë l

    2015-01-01

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event

  11. Analysis of extreme events

    CSIR Research Space (South Africa)

    Khuluse, S

    2009-04-01

    Full Text Available ) determination of the distribution of the damage and (iii) preparation of products that enable prediction of future risk events. The methodology provided by extreme value theory can also be a powerful tool in risk analysis...

  12. Acute lower extremity ischaemia

    African Journals Online (AJOL)

    Acute lower extremity ischaemia. Acute lower limb ischaemia is a surgical emergency. ... is ~1.5 cases per 10 000 persons per year. Acute ischaemia ... Table 2. Clinical features discriminating embolic from thrombotic ALEXI. Clinical features.

  13. Chitin utilization by the insect-transmitted bacterium Xylella fastidiosa.

    Science.gov (United States)

    Killiny, Nabil; Prado, Simone S; Almeida, Rodrigo P P

    2010-09-01

    Xylella fastidiosa is an insect-borne bacterium that colonizes xylem vessels of a large number of host plants, including several crops of economic importance. Chitin is a polysaccharide present in the cuticle of leafhopper vectors of X. fastidiosa and may serve as a carbon source for this bacterium. Biological assays showed that X. fastidiosa reached larger populations in the presence of chitin. Additionally, chitin induced phenotypic changes in this bacterium, notably increasing adhesiveness. Quantitative PCR assays indicated transcriptional changes in the presence of chitin, and an enzymatic assay demonstrated chitinolytic activity by X. fastidiosa. An ortholog of the chitinase A gene (chiA) was identified in the X. fastidiosa genome. The in silico analysis revealed that the open reading frame of chiA encodes a protein of 351 amino acids with an estimated molecular mass of 40 kDa. chiA is in a locus that consists of genes implicated in polysaccharide degradation. Moreover, this locus was also found in the genomes of closely related bacteria in the genus Xanthomonas, which are plant but not insect associated. X. fastidiosa degraded chitin when grown on a solid chitin-yeast extract-agar medium and grew in liquid medium with chitin as the sole carbon source; ChiA was also determined to be secreted. The gene encoding ChiA was cloned into Escherichia coli, and endochitinase activity was detected in the transformant, showing that the gene is functional and involved in chitin degradation. The results suggest that X. fastidiosa may use its vectors' foregut surface as a carbon source. In addition, chitin may trigger X. fastidiosa's gene regulation and biofilm formation within vectors. Further work is necessary to characterize the role of chitin and its utilization in X. fastidiosa.

  14. Extreme Programming: Maestro Style

    Science.gov (United States)

    Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

    2009-01-01

    "Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme

  15. Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

    Science.gov (United States)

    Loehr, Johannes; Pfeiffer, Daniel; Schüler, Dirk; Fischer, Thomas M

    2016-04-21

    Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain.

  16. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  17. Extreme meteorological conditions

    International Nuclear Information System (INIS)

    Altinger de Schwarzkopf, M.L.

    1983-01-01

    Different meteorological variables which may reach significant extreme values, such as the windspeed and, in particular, its occurrence through tornadoes and hurricanes that necesarily incide and wich must be taken into account at the time of nuclear power plants' installation, are analyzed. For this kind of study, it is necessary to determine the basic phenomenum of design. Two criteria are applied to define the basic values of design for extreme meteorological variables. The first one determines the expected extreme value: it is obtained from analyzing the recurence of the phenomenum in a convened period of time, wich may be generally of 50 years. The second one determines the extreme value of low probability, taking into account the nuclear power plant's operating life -f.ex. 25 years- and considering, during said lapse, the occurrence probabilities of extreme meteorological phenomena. The values may be determined either by the deterministic method, which is based on the acknowledgement of the fundamental physical characteristics of the phenomena or by the probabilistic method, that aims to the analysis of historical statistical data. Brief comments are made on the subject in relation to the Argentine Republic area. (R.J.S.) [es

  18. Bidirectional gene sequences with similar homology to functional proteins of alkane degrading bacterium pseudomonas fredriksbergensis DNA

    International Nuclear Information System (INIS)

    Megeed, A.A.

    2011-01-01

    The potential for two overlapping fragments of DNA from a clone of newly isolated alkanes degrading bacterium Pseudomonas frederiksbergensis encoding sequences with similar homology to two parts of functional proteins is described. One strand contains a sequence with high homology to alkanes monooxygenase (alkB), a member of the alkanes hydroxylase family, and the other strand contains a sequence with some homology to alcohol dehydrogenase gene (alkJ). Overlapping of the genes on opposite strands has been reported in eukaryotic species, and is now reported in a bacterial species. The sequence comparisons and ORFS results revealed that the regulation and the genes organization involved in alkane oxidation represented in Pseudomonas frederiksberghensis varies among the different known alkane degrading bacteria. The alk gene cluster containing homologues to the known alkane monooxygenase (alkB), and rubredoxin (alkG) are oriented in the same direction, whereas alcohol dehydrogenase (alkJ) is oriented in the opposite direction. Such genomes encode messages on both strands of the DNA, or in an overlapping but different reading frames, of the same strand of DNA. The possibility of creating novel genes from pre-existing sequences, known as overprinting, which is a widespread phenomenon in small viruses. Here, the origin and evolution of the gene overlap to bacteriophages belonging to the family Microviridae have been investigated. Such a phenomenon is most widely described in extremely small genomes such as those of viruses or small plasmids, yet here is a unique phenomenon. (author)

  19. Low-temperature chemotaxis, halotaxis and chemohalotaxis by the psychrophilic marine bacterium Colwellia psychrerythraea 34H.

    Science.gov (United States)

    Showalter, G M; Deming, J W

    2018-02-01

    A variety of ecologically important processes are driven by bacterial motility and taxis, yet these basic bacterial behaviours remain understudied in cold habitats. Here, we present a series of experiments designed to test the chemotactic ability of the model marine psychrophilic bacterium Colwellia psychrerythraea 34H, when grown at optimal temperature and salinity (8°C, 35 ppt) or its original isolation conditions (-1°C, 35 ppt), towards serine and mannose at temperatures from -8°C to 27°C (above its upper growth temperature of 18°C), and at salinities of 15, 35 and 55 ppt (at 8°C and -1°C). Results indicate that C. psychrerythraea 34H is capable of chemotaxis at all temperatures tested, with strongest chemotaxis at the temperature at which it was first grown, whether 8°C or -1°C. This model marine psychrophile also showed significant halotaxis towards 15 and 55 ppt solutions, as well as strong substrate-specific chemohalotaxis. We suggest that such patterns of taxis may enable bacteria to colonize sea ice, position themselves optimally within its extremely cold, hypersaline and temporally fluctuating microenvironments, and respond to various chemical signals therein. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and JohnWiley & Sons Ltd.

  20. Acclimatization to extreme heat

    Science.gov (United States)

    Warner, M. E.; Ganguly, A. R.; Bhatia, U.

    2017-12-01

    Heat extremes throughout the globe, as well as in the United States, are expected to increase. These heat extremes have been shown to impact human health, resulting in some of the highest levels of lives lost as compared with similar natural disasters. But in order to inform decision makers and best understand future mortality and morbidity, adaptation and mitigation must be considered. Defined as the ability for individuals or society to change behavior and/or adapt physiologically, acclimatization encompasses the gradual adaptation that occurs over time. Therefore, this research aims to account for acclimatization to extreme heat by using a hybrid methodology that incorporates future air conditioning use and installation patterns with future temperature-related time series data. While previous studies have not accounted for energy usage patterns and market saturation scenarios, we integrate such factors to compare the impact of air conditioning as a tool for acclimatization, with a particular emphasis on mortality within vulnerable communities.

  1. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  2. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.

    2015-04-10

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event of interest may be very limited, efficient methods of inference play an important role. This article reviews this domain, emphasizing current research topics. We first sketch the classical theory of extremes for maxima and threshold exceedances of stationary series. We then review multivariate theory, distinguishing asymptotic independence and dependence models, followed by a description of models for spatial and spatiotemporal extreme events. Finally, we discuss inference and describe two applications. Animations illustrate some of the main ideas. © 2015 by Annual Reviews. All rights reserved.

  3. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  4. Adventure and Extreme Sports.

    Science.gov (United States)

    Gomez, Andrew Thomas; Rao, Ashwin

    2016-03-01

    Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Extremal graph theory

    CERN Document Server

    Bollobas, Bela

    2004-01-01

    The ever-expanding field of extremal graph theory encompasses a diverse array of problem-solving methods, including applications to economics, computer science, and optimization theory. This volume, based on a series of lectures delivered to graduate students at the University of Cambridge, presents a concise yet comprehensive treatment of extremal graph theory.Unlike most graph theory treatises, this text features complete proofs for almost all of its results. Further insights into theory are provided by the numerous exercises of varying degrees of difficulty that accompany each chapter. A

  6. Cloning, expression, crystallization and preliminary X-ray characterization of cytochrome c552 from a moderate thermophilic bacterium, Hydrogenophilus thermoluteolus

    International Nuclear Information System (INIS)

    Ichiki, Shin-ichi; Nakamura, Shota; Ohkubo, Tadayasu; Kobayashi, Yuji; Hasegawa, Jun; Uchiyama, Susumu; Nishihara, Hirofumi; Mizuta, Keiko; Sambongi, Yoshihiro

    2005-01-01

    Cytochrome c 552 of a moderate thermophile, H. thermoluteolus, was overexpressed in E. coli and crystallized for X-ray diffraction study. The amino-acid sequence of cytochrome c 552 (PH c 552 ) from a moderately thermophilic bacterium, Hydrogenophilus thermoluteolus, was more than 50% identical to that of cytochrome c from an extreme thermophile, Hydrogenobacter thermophilus (HT c 552 ), and from a mesophile, Pseudomonas aeruginosa (PA c 551 ). The PH c 552 gene was overexpressed as a correctly processed holoprotein in the Escherichia coli periplasm. The overexpressed PH c 552 has been crystallized by vapour diffusion from polyethylene glycol 4000 pH 6.5. The crystals belong to space group C222 1 , with unit-cell parameters a = 48.98, b = 57.99, c = 56.20 Å. The crystals diffract X-rays to around 2.1 Å resolution

  7. Stellar extreme ultraviolet astronomy

    International Nuclear Information System (INIS)

    Cash, W.C. Jr.

    1978-01-01

    The design, calibration, and launch of a rocket-borne imaging telescope for extreme ultraviolet astronomy are described. The telescope, which employed diamond-turned grazing incidence optics and a ranicon detector, was launched November 19, 1976, from the White Sands Missile Range. The telescope performed well and returned data on several potential stellar sources of extreme ultraviolet radiation. Upper limits ten to twenty times more sensitive than previously available were obtained for the extreme ultraviolet flux from the white dwarf Sirius B. These limits fall a factor of seven below the flux predicted for the star and demonstrate that the temperature of Sirius B is not 32,000 K as previously measured, but is below 30,000 K. The new upper limits also rule out the photosphere of the white dwarf as the source of the recently reported soft x-rays from Sirius. Two other white dwarf stars, Feige 24 and G191-B2B, were observed. Upper limits on the flux at 300 A were interpreted as lower limits on the interstellar hydrogen column densities to these stars. The lower limits indicate interstellar hydrogen densitites of greater than .02 cm -3 . Four nearby stars (Sirius, Procyon, Capella, and Mirzam) were observed in a search for intense low temperature coronae or extended chromospheres. No extreme ultraviolet radiation from these stars was detected, and upper limits to their coronal emisson measures are derived

  8. Extremity x-ray

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003461.htm Extremity x-ray To use the sharing features on this page, ... in the body Risks There is low-level radiation exposure. X-rays are monitored and regulated to provide the ...

  9. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  10. Statistics of Local Extremes

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Bierbooms, W.; Hansen, Kurt Schaldemose

    2003-01-01

    . A theoretical expression for the probability density function associated with local extremes of a stochasticprocess is presented. The expression is basically based on the lower four statistical moments and a bandwidth parameter. The theoretical expression is subsequently verified by comparison with simulated...

  11. Single-step purification and characterization of an extreme halophilic, ethanol tolerant and acidophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 with application potential in the food industry.

    Science.gov (United States)

    Yegin, Sirma

    2017-04-15

    An extracellular xylanase from Aureobasidium pullulans NRRL Y-2311-1 produced on wheat bran was purified by a single-step chromatographic procedure. The enzyme had a molecular weight of 21.6kDa. The optimum pH and temperature for xylanase activity were 4.0 and 30-50°C, respectively. The enzyme was stable in the pH range of 3.0-8.0. The inactivation energy of the enzyme was calculated as 218kJmol -1 . The xylanase was ethanol tolerant and kept complete activity in the presence of 10% ethanol. Likewise, it retained almost complete activity at a concentration range of 0-20% NaCl. In general, the enzyme was resistant to several metal ions and reagents. Mg 2+ , Zn 2+ , Cu 2+ , K 1+ , EDTA and β-mercaptoethanol resulted in enhanced xylanase activity. The K m and V max values on beechwood xylan were determined to be 19.43mgml -1 and 848.4Uml -1 , respectively. The enzyme exhibits excellent characteristics and could, therefore, be a promising candidate for application in food and bio-industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Hydrogen production by co-cultures of Lactobacillus and a photosynthetic bacterium, Rhodobacter sphaeroides RV

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Yasuo; Ishimi, Katsuhiro [Department of General Education, College of Science and Technology, Nihon University, Narashinodai, Chiba 274-8501 (Japan); Tokumoto, Masaru; Aihara, Yasuyuki; Oku, Masayo; Kohno, Hideki [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Izumi-cho, Chiba 275-8575 (Japan); Wakayama, Tatsuki; Miyake, Jun [Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Nakoji, Amagasaki, Hyogo 661-0974 (Japan); Tomiyama, Masamitsu [Genetic Diversity Department, National Institute of Agrobiological Science, Tsukuba, Ibaraki 305-8602 (Japan)

    2006-09-15

    Hydrogen production with glucose by using co-immobilized cultures of a lactic acid bacterium, Lactobacillus delbrueckii NBRC13953, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. Glucose was converted to hydrogen gas in a yield of 7.1mol of hydrogen per mole of glucose at a maximum under illuminated conditions. (author)

  13. Dense populations of a giant sulfur bacterium in Namibian shelf sediments

    DEFF Research Database (Denmark)

    Schulz, HN; Brinkhoff, T.; Ferdelman, TG

    1999-01-01

    A previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the Benguela Current upwelling system. The bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. On the basis of 16S ribosomal DNA...

  14. Genome analysis of the anaerobic thermohalophilic bacterium Halothermothrix orenii.

    Directory of Open Access Journals (Sweden)

    Konstantinos Mavromatis

    Full Text Available Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  15. Genome analysis of the Anerobic Thermohalophilic bacterium Halothermothrix orenii

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Lykidis, Athanasios; Hooper, Sean D.; Sun, Hui; Kunin, Victor; Lapidus, Alla; Hugenholtz, Philip; Patel, Bharat; Kyrpides, Nikos C.

    2008-11-03

    Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  16. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    Science.gov (United States)

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and contained cytochrome c3 and desulfoviridin. Except for furfural degradation, the characteristics of the furfural isolate were remarkably similar to those of the sulfate reducer Desulfovibrio gigas. The furfural isolate has been tentatively identified as Desulfovibrio sp. strain F-1. Images PMID:16346423

  17. A bacterium that degrades and assimilates poly(ethylene terephthalate).

    Science.gov (United States)

    Yoshida, Shosuke; Hiraga, Kazumi; Takehana, Toshihiko; Taniguchi, Ikuo; Yamaji, Hironao; Maeda, Yasuhito; Toyohara, Kiyotsuna; Miyamoto, Kenji; Kimura, Yoshiharu; Oda, Kohei

    2016-03-11

    Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol. Copyright © 2016, American Association for the Advancement of Science.

  18. The O-antigen structure of bacterium Comamonas aquatica CJG.

    Science.gov (United States)

    Wang, Xiqian; Kondakova, Anna N; Zhu, Yutong; Knirel, Yuriy A; Han, Aidong

    2017-11-01

    Genus Comamonas is a group of bacteria that are able to degrade a variety of environmental waste. Comamonas aquatica CJG (C. aquatica) in this genus is able to absorb low-density lipoprotein but not high-density lipoprotein of human serum. Using 1 H and 13 C NMR spectroscopy, we found that the O-polysaccharide (O-antigen) of this bacterium is comprised of a disaccharide repeat (O-unit) of d-glucose and 2-O-acetyl-l-rhamnose, which is shared by Serratia marcescens O6. The O-antigen gene cluster of C. aquatica, which is located between coaX and tnp4 genes, contains rhamnose synthesis genes, glycosyl and acetyl transferase genes, and ATP-binding cassette transporter genes, and therefore is consistent with the O-antigen structure determined here.

  19. A PerR-like protein involved in response to oxidative stress in the extreme bacterium Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chengzhi; Wang, Liangyan; Li, Tao; Lin, Lin; Dai, Shang; Tian, Bing, E-mail: tianbing@zju.edu.cn; Hua, Yuejin, E-mail: yjhua@zju.edu.cn

    2014-07-18

    Highlights: • We report a novel PerR-like protein of Fur family in D. radiodurans that is not annotated in the current database. • drperR responses to H{sub 2}O{sub 2} and functions as a negative regulator of katE and dps. • We provided implications on how to utilize sequenced genome data and the importance of genome data mining. • This study adds knowledge to complicated regulatory network that responds to ROS stress in D. radiodurans. - Abstract: Response and defense systems against reactive oxygen species (ROS) contribute to the remarkable resistance of Deinococcus radiodurans to oxidative stress induced by oxidants or radiation. However, mechanisms involved in ROS response and defense systems of D. radiodurans are not well understood. Fur family proteins are important in ROS response. Only a single Fur homolog is predicted by sequence similarity in the current D. radiodurans genome database. Our bioinformatics analysis demonstrated an additional guanine nucleotide in the genome of D. radiodurans that is not in the database, leading to the discovery of another Fur homolog DrPerR. Gene disruption mutant of DrPerR showed enhanced resistance to hydrogen peroxide (H{sub 2}O{sub 2}) and increased catalase activity in cell extracts. Real-time PCR results indicated that DrPerR functions as a repressor of the catalase gene katE. Meanwhile, derepression of dps (DNA-binding proteins from starved cells) gene under H{sub 2}O{sub 2} stress by DrPerR point to its regulatory role in metal ions hemostasis. Thus, DrPerR might function as a Fur homolog protein which is involved in ROS response and defense. These results help clarify the complicated regulatory network that responds to ROS stress in D. radiodurans.

  20. A PerR-like protein involved in response to oxidative stress in the extreme bacterium Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Liu, Chengzhi; Wang, Liangyan; Li, Tao; Lin, Lin; Dai, Shang; Tian, Bing; Hua, Yuejin

    2014-01-01

    Highlights: • We report a novel PerR-like protein of Fur family in D. radiodurans that is not annotated in the current database. • drperR responses to H 2 O 2 and functions as a negative regulator of katE and dps. • We provided implications on how to utilize sequenced genome data and the importance of genome data mining. • This study adds knowledge to complicated regulatory network that responds to ROS stress in D. radiodurans. - Abstract: Response and defense systems against reactive oxygen species (ROS) contribute to the remarkable resistance of Deinococcus radiodurans to oxidative stress induced by oxidants or radiation. However, mechanisms involved in ROS response and defense systems of D. radiodurans are not well understood. Fur family proteins are important in ROS response. Only a single Fur homolog is predicted by sequence similarity in the current D. radiodurans genome database. Our bioinformatics analysis demonstrated an additional guanine nucleotide in the genome of D. radiodurans that is not in the database, leading to the discovery of another Fur homolog DrPerR. Gene disruption mutant of DrPerR showed enhanced resistance to hydrogen peroxide (H 2 O 2 ) and increased catalase activity in cell extracts. Real-time PCR results indicated that DrPerR functions as a repressor of the catalase gene katE. Meanwhile, derepression of dps (DNA-binding proteins from starved cells) gene under H 2 O 2 stress by DrPerR point to its regulatory role in metal ions hemostasis. Thus, DrPerR might function as a Fur homolog protein which is involved in ROS response and defense. These results help clarify the complicated regulatory network that responds to ROS stress in D. radiodurans

  1. Thermoanaerobacter pentosaceus sp. nov., an anaerobic, extreme thermophilic, high ethanol-yielding bacterium isolated from household waste

    DEFF Research Database (Denmark)

    Tomás, Ana Faria; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2013-01-01

    of approximately 0.5 µm. Optimal growth occurred at 70 °C and pH(25°C) 7, with a maximum growth rate of 0.1 h-1. DNA G+C content was 34.2 mol %. Strain DTU01(T) could ferment arabinose, cellobiose, fructose, galactose, glucose, inulin, lactose, mannose, melibiose, pectin, starch, sucrose, xylan, yeast extract...

  2. Evaluation of the effects of Extremely Low Frequency (ELF Pulsed Electromagnetic Fields (PEMF on survival of the bacterium Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Ahmed Istiaque

    2013-12-01

    In summary, the growth rate of the irradiated S. aureus bacteria is affected by radiation of particular parameters, thus revealing resonant effects induced by the applied radiation. The decreased CFU values in all irradiated samples compared to control samples (non-exposed were observed. Findings provide important insight towards selecting the optimal parameters of ELF PEMF for possible treatment of infected tissue and thus, wound healing promotion.

  3. Extremes in nature

    CERN Document Server

    Salvadori, Gianfausto; Kottegoda, Nathabandu T

    2007-01-01

    This book is about the theoretical and practical aspects of the statistics of Extreme Events in Nature. Most importantly, this is the first text in which Copulas are introduced and used in Geophysics. Several topics are fully original, and show how standard models and calculations can be improved by exploiting the opportunities offered by Copulas. In addition, new quantities useful for design and risk assessment are introduced.

  4. Rhabdomyosarcoma of the extremity

    International Nuclear Information System (INIS)

    Rao, Bhaskar N

    1997-01-01

    Rhabdomyosarcoma is the most common soft tissue sarcoma accounting for almost 55%. These tumors arise from unsegmented mesoderm or primitive mesenchyma, which have the capacity to differentiate into muscle. Less than 5% occur in the first year of life. Extremity rhabdomyosarcoma are mainly seen in the adolescent years. The most common histologic subtype is the alveolar variant. Other characteristics of extremity rhabdomyosarcoma include a predilection for lymph node metastasis, a high local failure, and a relatively low survival rate. They often present as slow painless masses; however, lesions in the hand and foot often present as painful masses and imaging studies may show invasion of the bone. Initial diagnostic approaches include needle biopsy or incisional biopsy for larger lesions. Excisional biopsy is indicated preferably for lesions less than 2.5 cm. following this in most instances therapy is initiated with multi agent chemotherapy depending upon response, the next modality may be either surgery with intent to cure or radiation therapy. Amputation of an extremity for local control is not considered in most instances. Prognostic factors that have been determined over the years to be of significance by multi variant analysis have included age, tumor size, invasiveness, presence of either nodal or distant metastasis, and complete excision whenever feasible, with supplemental radiation therapy for local control

  5. Complete genome sequence of the photoautotrophic and bacteriochlorophyll e-synthesizing green sulfur bacterium Chlorobaculum limnaeum DSM 1677T

    DEFF Research Database (Denmark)

    Tank, Marcus; Liu, Zhenfeng; Frigaard, Niels-Ulrik

    2017-01-01

    Chlorobaculum limnaeum DSM 1677T is a mesophilic, brown-colored, chlorophototrophic green sulfur bacterium that produces bacteriochlorophyll e and the carotenoid isorenieratene as major pigments. This bacterium serves as a model organism in molecular research on photosynthesis, sulfur metabolism...

  6. Genomics of an extreme psychrophile, Psychromonas ingrahamii

    Directory of Open Access Journals (Sweden)

    Hauser Loren J

    2008-05-01

    Full Text Available Abstract Background The genome sequence of the sea-ice bacterium Psychromonas ingrahamii 37, which grows exponentially at -12C, may reveal features that help to explain how this extreme psychrophile is able to grow at such low temperatures. Determination of the whole genome sequence allows comparison with genes of other psychrophiles and mesophiles. Results Correspondence analysis of the composition of all P. ingrahamii proteins showed that (1 there are 6 classes of proteins, at least one more than other bacteria, (2 integral inner membrane proteins are not sharply separated from bulk proteins suggesting that, overall, they may have a lower hydrophobic character, and (3 there is strong opposition between asparagine and the oxygen-sensitive amino acids methionine, arginine, cysteine and histidine and (4 one of the previously unseen clusters of proteins has a high proportion of "orphan" hypothetical proteins, raising the possibility these are cold-specific proteins. Based on annotation of proteins by sequence similarity, (1 P. ingrahamii has a large number (61 of regulators of cyclic GDP, suggesting that this bacterium produces an extracellular polysaccharide that may help sequester water or lower the freezing point in the vicinity of the cell. (2 P. ingrahamii has genes for production of the osmolyte, betaine choline, which may balance the osmotic pressure as sea ice freezes. (3 P. ingrahamii has a large number (11 of three-subunit TRAP systems that may play an important role in the transport of nutrients into the cell at low temperatures. (4 Chaperones and stress proteins may play a critical role in transforming nascent polypeptides into 3-dimensional configurations that permit low temperature growth. (5 Metabolic properties of P. ingrahamii were deduced. Finally, a few small sets of proteins of unknown function which may play a role in psychrophily have been singled out as worthy of future study. Conclusion The results of this genomic analysis

  7. Extreme Programming Pocket Guide

    CERN Document Server

    Chromatic

    2003-01-01

    Extreme Programming (XP) is a radical new approach to software development that has been accepted quickly because its core practices--the need for constant testing, programming in pairs, inviting customer input, and the communal ownership of code--resonate with developers everywhere. Although many developers feel that XP is rooted in commonsense, its vastly different approach can bring challenges, frustrations, and constant demands on your patience. Unless you've got unlimited time (and who does these days?), you can't always stop to thumb through hundreds of pages to find the piece of info

  8. Upper extremity golf injuries.

    Science.gov (United States)

    Cohn, Michael A; Lee, Steven K; Strauss, Eric J

    2013-01-01

    Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.

  9. Probing the redox metabolism in the strictly anaerobic, extremely thermophilic, hydrogen-producing Caldicellulosiruptor saccharolyticus using amperometry

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Willquist, Karin; Emnéus, Jenny

    2011-01-01

    Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellul...... in the intracellular electron flow and to probe redox enzyme properties of a strictly anaerobic thermophile in vivo.......Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellular...... the NADH-dependent lactate dehydrogenase, upon which more NADH was directed to membrane-associated enzymes for ferricyanide reduction, leading to a higher electrochemical signal. The method is noninvasive and the results presented here demonstrate that this method can be used to accurately detect changes...

  10. Bordetella bronchiseptica Pneumonia in an Extremely-Low-Birth-Weight Neonate

    Directory of Open Access Journals (Sweden)

    Yuk Joseph Ting

    2011-12-01

    Full Text Available Bordetella bronchiseptica, a gram-negative coccobacillus, is a common veterinary pathogen. In both domestic and wild animals, this bacterium causes respiratory infections including infectious tracheobronchitis in dogs and atrophic rhinitis in swine. Human infections are rare and have been documented in immunocompromised hosts. Here, we describe an extremely-low-birth-weight infant with B. bronchiseptica pneumonia. This is the first report that describes the microorganism's responsibility in causing nosocomial infection in a preterm neonate. He recovered uneventfully after a course of meropenem. It is possible that the bacteria colonize the respiratory tracts of our health care workers or parents who may have had contact with pets and then transmitted the bacterium to our patient. Follow-up until 21 months of age showed normal growth and development. He did not suffer from any significant residual respiratory disease.

  11. Anoxybacillus vitaminiphilus sp. nov., a strictly aerobic and moderately thermophilic bacterium isolated from a hot spring.

    Science.gov (United States)

    Zhang, Xin-Qi; Zhang, Zhen-Li; Wu, Nan; Zhu, Xu-Fen; Wu, Min

    2013-11-01

    A strictly aerobic, Gram-stain-positive, motile and spore-forming bacterium, strain 3nP4(T), was isolated from the Puge hot spring located in the south-western geothermal area of China. Strain 3nP4(T) grew at 38-66 °C (optimum 57-60 °C), at pH 6.0-9.3 (optimum 7.0-7.5) and with 0-4 % (w/v) NaCl (optimum 0-0.5 %). Phylogenetic analysis of 16S rRNA gene sequences, as well as DNA-DNA relatedness values, indicated that the isolate represents a novel species of the genus Anoxybacillus, related most closely to Anoxybacillus voinovskiensis DSM 12111(T). Strain 3nP4(T) had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and one unidentified phospholipid as major polar lipids and iso-C15 : 0 and iso-C17 : 0 as major fatty acids, which are both typical chemotaxonomic characteristics of the genus Anoxybacillus. The mean DNA G+C content of strain 3nP4(T) was 39.2±0.95 mol% (HPLC). A distinctive characteristic of the novel isolate was its extreme reliance on vitamin mixture or yeast extract for growth. Based on data from this taxonomic study using a polyphasic approach, strain 3nP4(T) is considered to represent a novel species of the genus Anoxybacillus, for which the name Anoxybacillus vitaminiphilus sp. nov. is proposed. The type strain is 3nP4(T) ( = CGMCC 1.8979(T) = JCM 16594(T)).

  12. The Endosymbiotic Bacterium Wolbachia Selectively Kills Male Hosts by Targeting the Masculinizing Gene.

    Directory of Open Access Journals (Sweden)

    Takahiro Fukui

    2015-07-01

    Full Text Available Pathogens are known to manipulate the reproduction and development of their hosts for their own benefit. Wolbachia is an endosymbiotic bacterium that infects a wide range of insect species. Wolbachia is known as an example of a parasite that manipulates the sex of its host's progeny. Infection of Ostrinia moths by Wolbachia causes the production of all-female progeny, however, the mechanism of how Wolbachia accomplishes this male-specific killing is unknown. Here we show for the first time that Wolbachia targets the host masculinizing gene of Ostrinia to accomplish male-killing. We found that Wolbachia-infected O. furnacalis embryos do not express the male-specific splice variant of doublesex, a gene which acts at the downstream end of the sex differentiation cascade, throughout embryonic development. Transcriptome analysis revealed that Wolbachia infection markedly reduces the mRNA level of Masc, a gene that encodes a protein required for both masculinization and dosage compensation in the silkworm Bombyx mori. Detailed bioinformatic analysis also elucidated that dosage compensation of Z-linked genes fails in Wolbachia-infected O. furnacalis embryos, a phenomenon that is extremely similar to that observed in Masc mRNA-depleted male embryos of B. mori. Finally, injection of in vitro transcribed Masc cRNA into Wolbachia-infected embryos rescued male progeny. Our results show that Wolbachia-induced male-killing is caused by a failure of dosage compensation via repression of the host masculinizing gene. Our study also shows a novel strategy by which a pathogen hijacks the host sex determination cascade.

  13. Electromicrobiology of Dissimilatory Sulfur Reducing Bacterium Desulfuromonas acetexigens

    KAUST Repository

    Bin Bandar, Khaled

    2014-12-01

    Bioelectrochmical systems (BES) are engineered electrochemical devices that harness hidden chemical energy of the wastewater in to the form of electricity or hydrogen. Unique microbial communities enrich in these systems for oxidation of organic matter as well as transfer of resulted electron to anode, known them as “electricigens” communities. Exploring novel electricigenesis microbial communities in the nature and understanding their electromicrobiology is one the important aspect for BES systems scale up. Herein, we report first time the electricigenesis property of an anaerobic, fresh water sediment, sulfur reducing bacterium Desulfuromona acetexigens. The electrochemical behavior of D. acetexigens biofilms grown on graphite-rod electrodes in batch-fed mode under an applied potential was investigated with traditional electroanalytical tools, and correlate the electron transfer from biofilms to electrode with a model electricigen Geobacter sulfurreducens electrochemical behavior. Research findings suggest that D. acetexigens has the ability to use electrode as electron acceptor in BES systems through establishing the direct contact with anode by expressing the membrane bound redox proteins, but not due to the secretion of soluble redox mediators. Preliminary results revealed that D. acetexigens express three distinct redox proteins in their membranes for turnover of the electrons from biofilm to electrode, and the 4 whole electricigenesis process observed to be unique in the D. acetexigens compared to that of well-studied model organism G. sulfurreducens.

  14. Yersinia ruckeri sp. nov., the redmouth (RM) bacterium

    Science.gov (United States)

    Ewing, W.H.; Ross, A.J.; Brenner, Don J.; Fanning, G. R.

    1978-01-01

    Cultures of the redmouth (RM) bacterium, one of the etiological agents of redmouth disease in rainbow trout (Salmo gairdneri) and certain other fishes, were characterized by means of their biochemical reactions, by deoxyribonucleic acid (DNA) hybridization, and by determination of guanine-plus-cytosine (G+C) ratios in DNA. The DNA relatedness studies confirmed the fact that the RM bacteria are members of the family Enterobacteriaceae and that they comprise a single species that is not closely related to any other species of Enterobacteriaceae. They are about 30% related to species of both Serratia and Yersinia. A comparison of the biochemical reactions of RM bacteria and serratiae indicated that there are many differences between these organisms and that biochemically the RM bacteria are most closely related to yersiniae. The G+C ratios of RM bacteria were approximated to be between 47.5 and 48.5% These values are similar to those of yersiniae but markedly different from those of serratiae. On the basis of their biochemical reactions and their G+C ratios, the RM bacteria are considered to be a new species of Yersinia, for which the name Yersinia ruckeri is proposed. Strain 2396-61 (= ATCC 29473) is designated the type strain of the species.

  15. Investigating NARCCAP Precipitation Extremes via Bivariate Extreme Value Theory (Invited)

    Science.gov (United States)

    Weller, G. B.; Cooley, D. S.; Sain, S. R.; Bukovsky, M. S.; Mearns, L. O.

    2013-12-01

    We introduce methodology from statistical extreme value theory to examine the ability of reanalysis-drive regional climate models to simulate past daily precipitation extremes. Going beyond a comparison of summary statistics such as 20-year return values, we study whether the most extreme precipitation events produced by climate model simulations exhibit correspondence to the most extreme events seen in observational records. The extent of this correspondence is formulated via the statistical concept of tail dependence. We examine several case studies of extreme precipitation events simulated by the six models of the North American Regional Climate Change Assessment Program (NARCCAP) driven by NCEP reanalysis. It is found that the NARCCAP models generally reproduce daily winter precipitation extremes along the Pacific coast quite well; in contrast, simulation of past daily summer precipitation extremes in a central US region is poor. Some differences in the strength of extremal correspondence are seen in the central region between models which employ spectral nudging and those which do not. We demonstrate how these techniques may be used to draw a link between extreme precipitation events and large-scale atmospheric drivers, as well as to downscale extreme precipitation simulated by a future run of a regional climate model. Specifically, we examine potential future changes in the nature of extreme precipitation along the Pacific coast produced by the pineapple express (PE) phenomenon. A link between extreme precipitation events and a "PE Index" derived from North Pacific sea-surface pressure fields is found. This link is used to study PE-influenced extreme precipitation produced by a future-scenario climate model run.

  16. Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

    Science.gov (United States)

    Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic char (Salvelinus alpinus). To characterize a bacterium associated with epitheliocystis in cultured char, gills were sampled for histopathologic examination, conventional...

  17. Echinicola shivajiensis sp. nov., a novel bacterium of the family "Cyclobacteriaceae" isolated from brackish water pond

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; Tryambak, B.K.; AnilKumar, P.

    Strain AK12 sup(T), an orange pigmented Gramnegative, rod shaped, non-motile bacterium, was isolated fromamud sample collected froma brackishwater pond at Rampur of West Bengal, India. The strain was positive for oxidase, catalase and phosphatase...

  18. Reclassification of Clostridium proteoclasticum as Butyrivibrio proteoclasticus comb. nov., a butyrate-producing ruminal bacterium

    Czech Academy of Sciences Publication Activity Database

    Moon, C. D.; Pacheco, D. M.; Kelly, W. J.; Leahy, S. C.; Li, D.; Kopečný, Jan; Attwood, G. T.

    2008-01-01

    Roč. 58, - (2008), s. 2041-2045 ISSN 1466-5026 Institutional research plan: CEZ:AV0Z50450515 Keywords : Butyrivibrio * ruminal bacterium Subject RIV: EE - Microbiology, Virology Impact factor: 2.222, year: 2008

  19. Septicemia caused by the gram-negative bacterium CDC IV c-2 in an immunocompromised human.

    OpenAIRE

    Dan, M; Berger, S A; Aderka, D; Levo, Y

    1986-01-01

    A 37-year-old man with plasma cell leukemia developed nonfatal septicemia caused by the gram-negative bacterium CDC IV c-2. Recovery followed appropriate treatment with antibiotics. The biochemical features of this organism are reviewed.

  20. Complete genome of Martelella sp. AD-3, a moderately halophilic polycyclic aromatic hydrocarbons-degrading bacterium.

    Science.gov (United States)

    Cui, Changzheng; Li, Zhijie; Qian, Jiangchao; Shi, Jie; Huang, Ling; Tang, Hongzhi; Chen, Xin; Lin, Kuangfei; Xu, Ping; Liu, Yongdi

    2016-05-10

    Martelella sp. strain AD-3, a moderate halophilic bacterium, was isolated from a petroleum-contaminated soil with high salinity in China. Here, we report the complete genome of strain AD-3, which contains one circular chromosome and two circular plasmids. An array of genes related to metabolism of polycyclic aromatic hydrocarbons and halophilic mechanism in this bacterium was identified by the whole genome analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.

    Directory of Open Access Journals (Sweden)

    Michele T Hoffman

    Full Text Available Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA, often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales, but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales. Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.

  2. Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.

    Science.gov (United States)

    Reeve, C A; Baldwin, T O

    1981-06-01

    Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.

  3. Are BALQSOs extreme accretors?

    Science.gov (United States)

    Yuan, M. J.; Wills, B. J.

    2002-12-01

    Broad Absorption Line (BAL) QSOs are QSOs with massive absorbing outflows up to 0.2c. Two hypothesis have been suggested in the past about the nature of BALQSOs: Every QSO might have BAL outflow with some covering factor. BALQSOs are those which happen to have outflow along our line of sight. BALQSOs have intrinsically different physical properties than non-BALQSOs. Based on BALQSO's optical emission properties and a large set of correlations linking many general QSO emission line and continuum properties, it has been suggested that BALQSOs might accrete at near Eddington limit with abundant of fuel supplies. With new BALQSO Hβ region spectroscopic observation conducted at UKIRT and re-analysis of literature data for low and high redshift non-BALQSOs, We confirm that BALQSOs have extreme Fe II and [O III] emission line properties. Using results derived from the latest QSO Hβ region reverberation mapping, we calculated Eddington ratios (˙ {M}/˙ {M}Edd) for our BAL and non-BALQSOs. The Fe II and [O III] strengths are strongly correlated with Eddington ratios. Those correlations link Eddington ratio to a large set of general QSO properties through the Boroson & Green Eigenvector 1. We find that BALQSOs have Eddington ratios close to 1. However, all high redshift, high luminosity QSOs have rather high Eddington ratios. We argue that this is a side effect from selecting the brightest objects. In fact, our high redshift sample might constitute BALQSO's high Eddington ratio orientation parent population.

  4. A note on extreme sets

    Directory of Open Access Journals (Sweden)

    Radosław Cymer

    2017-10-01

    Full Text Available In decomposition theory, extreme sets have been studied extensively due to its connection to perfect matchings in a graph. In this paper, we first define extreme sets with respect to degree-matchings and next investigate some of their properties. In particular, we prove the generalized Decomposition Theorem and give a characterization for the set of all extreme vertices in a graph.

  5. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects.

    Science.gov (United States)

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2016-06-02

    Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others) which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as 'Immunopotentiator from Pantoea agglomerans 1 (IP-PA1)' reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of plant resistance. Its use as

  6. Pantoea agglomerans : a mysterious bacterium of evil and good. Part IV. Beneficial effects

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2016-06-01

    Full Text Available Pantoea agglomerans , a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as ‘Immunopotentiator from Pantoea agglomerans 1 (IP-PA1’ reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti- Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of

  7. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2016-06-01

    Full Text Available [i][/i][i]Pantoea agglomerans[/i], a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of [i]P. agglomerans[/i] isolated by them and described as ‘Immunopotentiator from [i]Pantoea agglomerans[/i] 1 (IP-PA1’ reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that [i]P. agglomerans[/i] occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the [i]Plasmodium[/i] parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-[i]Plasmodium[/i] effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. [i]Pantoea agglomerans[/i] has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic

  8. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaë l; Davison, Anthony C.; Genton, Marc G.

    2015-01-01

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  9. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaël

    2015-11-17

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  10. Further outlooks: extremely uncomfortable; Die weiteren Aussichten: extrem ungemuetlich

    Energy Technology Data Exchange (ETDEWEB)

    Resenhoeft, T.

    2006-07-01

    Climate is changing extremely in the last decades. Scientists dealing with extreme weather, should not only stare at computer simulations. They have also to turn towards psyche, seriously personal experiences, knowing statistics, relativise supposed sensational reports and last not least collecting more data. (GL)

  11. Assessing Climate Variability using Extreme Rainfall and ...

    African Journals Online (AJOL)

    user1

    extreme frequency); the average intensity of rainfall from extreme events ... frequency and extreme intensity indices, suggesting that extreme events are more frequent and intense during years with high rainfall. The proportion of total rainfall from ...

  12. A Genetic System for the Thermophilic Acetogenic Bacterium Thermoanaerobacter kivui.

    Science.gov (United States)

    Basen, Mirko; Geiger, Irina; Henke, Laura; Müller, Volker

    2018-02-01

    Thermoanaerobacter kivui is one of the very few thermophilic acetogenic microorganisms. It grows optimally at 66°C on sugars but also lithotrophically with H 2 + CO 2 or with CO, producing acetate as the major product. While a genome-derived model of acetogenesis has been developed, only a few physiological or biochemical experiments regarding the function of important enzymes in carbon and energy metabolism have been carried out. To address this issue, we developed a method for targeted markerless gene deletions and for integration of genes into the genome of T. kivui The strain naturally took up plasmid DNA in the exponential growth phase, with a transformation frequency of up to 3.9 × 10 -6 A nonreplicating plasmid and selection with 5-fluoroorotate was used to delete the gene encoding the orotate phosphoribosyltransferase ( pyrE ), resulting in a Δ pyrE uracil-auxotrophic strain, TKV002. Reintroduction of pyrE on a plasmid or insertion of pyrE into different loci within the genome restored growth without uracil. We subsequently studied fructose metabolism in T. kivui The gene fruK (TKV_c23150) encoding 1-phosphofructosekinase (1-PFK) was deleted, using pyrE as a selective marker via two single homologous recombination events. The resulting Δ fruK strain, TKV003, did not grow on fructose; however, growth on glucose (or on mannose) was unaffected. The combination of pyrE as a selective marker and the natural competence of the strain for DNA uptake will be the basis for future studies on CO 2 reduction and energy conservation and their regulation in this thermophilic acetogenic bacterium. IMPORTANCE Acetogenic bacteria are currently the focus of research toward biotechnological applications due to their potential for de novo synthesis of carbon compounds such as acetate, butyrate, or ethanol from H 2 + CO 2 or from synthesis gas. Based on available genome sequences and on biochemical experiments, acetogens differ in their energy metabolism. Thus, there is an

  13. Management of the mangled extremity

    NARCIS (Netherlands)

    Prasarn, Mark L.; Helfet, David L.; Kloen, Peter

    2012-01-01

    The management of a mangled extremity continues to be a matter of debate. With modern advances in trauma resuscitation, microvascular tissue transfer, and fracture fixation, severe traumatic extremity injuries that would historically have been amputated are often salvaged. Even if preserving a

  14. A decade of weather extremes

    NARCIS (Netherlands)

    Coumou, Dim; Rahmstorf, Stefan

    The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme - notably heatwaves, but also

  15. Attitude extremity, consensus and diagnosticity

    NARCIS (Netherlands)

    van der Pligt, J.; Ester, P.; van der Linden, J.

    1983-01-01

    Studied the effects of attitude extremity on perceived consensus and willingness to ascribe trait terms to others with either pro- or antinuclear attitudes. 611 Ss rated their attitudes toward nuclear energy on a 5-point scale. Results show that attitude extremity affected consensus estimates. Trait

  16. Adaptation of Bacillus subtilis to Life at Extreme Potassium Limitation.

    Science.gov (United States)

    Gundlach, Jan; Herzberg, Christina; Hertel, Dietrich; Thürmer, Andrea; Daniel, Rolf; Link, Hannes; Stülke, Jörg

    2017-07-05

    Potassium is the most abundant metal ion in every living cell. This ion is essential due to its requirement for the activity of the ribosome and many enzymes but also because of its role in buffering the negative charge of nucleic acids. As the external concentrations of potassium are usually low, efficient uptake and intracellular enrichment of the ion is necessary. The Gram-positive bacterium Bacillus subtilis possesses three transporters for potassium, KtrAB, KtrCD, and the recently discovered KimA. In the absence of the high-affinity transporters KtrAB and KimA, the bacteria were unable to grow at low potassium concentrations. However, we observed the appearance of suppressor mutants that were able to overcome the potassium limitation. All these suppressor mutations affected amino acid metabolism, particularly arginine biosynthesis. In the mutants, the intracellular levels of ornithine, citrulline, and arginine were strongly increased, suggesting that these amino acids can partially substitute for potassium. This was confirmed by the observation that the supplementation with positively charged amino acids allows growth of B. subtilis even at the extreme potassium limitation that the bacteria experience if no potassium is added to the medium. In addition, a second class of suppressor mutations allowed growth at extreme potassium limitation. These mutations result in increased expression of KtrAB, the potassium transporter with the highest affinity and therefore allow the acquisition and accumulation of the smallest amounts of potassium ions from the environment. IMPORTANCE Potassium is essential for every living cell as it is required for the activity for many enzymes and for maintaining the intracellular pH by buffering the negative charge of the nucleic acids. We have studied the adaptation of the soil bacterium Bacillus subtilis to life at low potassium concentrations. If the major high-affinity transporters are missing, the bacteria are unable to grow

  17. Antibacterial Property of a Coral-Associated Bacterium Pseudoalteromonas luteoviolacea Against Shrimp Pathogenic Vibrio harveyi (In Vitro Study)

    OpenAIRE

    OCKY KARNA RADJASA; TORBEN MARTENS; HANS-PETER GROSSART; AGUS SABDONO; MEINHARD SIMON; TONNY BACHTIAR

    2005-01-01

    A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA. The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved s...

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

    Science.gov (United States)

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

    2013-03-01

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

  19. Spatial dependence of extreme rainfall

    Science.gov (United States)

    Radi, Noor Fadhilah Ahmad; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Azman, Muhammad Az-zuhri

    2017-05-01

    This study aims to model the spatial extreme daily rainfall process using the max-stable model. The max-stable model is used to capture the dependence structure of spatial properties of extreme rainfall. Three models from max-stable are considered namely Smith, Schlather and Brown-Resnick models. The methods are applied on 12 selected rainfall stations in Kelantan, Malaysia. Most of the extreme rainfall data occur during wet season from October to December of 1971 to 2012. This period is chosen to assure the available data is enough to satisfy the assumption of stationarity. The dependence parameters including the range and smoothness, are estimated using composite likelihood approach. Then, the bootstrap approach is applied to generate synthetic extreme rainfall data for all models using the estimated dependence parameters. The goodness of fit between the observed extreme rainfall and the synthetic data is assessed using the composite likelihood information criterion (CLIC). Results show that Schlather model is the best followed by Brown-Resnick and Smith models based on the smallest CLIC's value. Thus, the max-stable model is suitable to be used to model extreme rainfall in Kelantan. The study on spatial dependence in extreme rainfall modelling is important to reduce the uncertainties of the point estimates for the tail index. If the spatial dependency is estimated individually, the uncertainties will be large. Furthermore, in the case of joint return level is of interest, taking into accounts the spatial dependence properties will improve the estimation process.

  20. Evolution caused by extreme events.

    Science.gov (United States)

    Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna

    2017-06-19

    Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  1. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Mun Su [University of Florida, Gainesville; Moritz, Brelan E. [University of Florida, Gainesville; Xie, Gary [Los Alamos National Laboratory (LANL); Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chertkov, Olga [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Han, Cliff [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Patel, Milind [University of Florida, Gainesville; Ou, Mark [University of Florida, Gainesville; Harbrucker, Roberta [University of Florida, Gainesville; Ingram, Lonnie O. [University of Florida; Shanmugam, Keelnathan T. [University of Florida

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer- ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this spo- rogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attrac- tive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi- cellulose. This bacterium is also considered as a potential probiotic. Complete genome se- quence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  2. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Gary [Los Alamos National Laboratory (LANL); Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer-ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi-cellulose. This bacterium is also considered as a potential probiotic. Complete genome squence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  3. Moritella viscosa, a pathogenic bacterium affecting the fillet quality in fish

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian; Nielsen, Michael Engelbrecht

    2011-01-01

    Moritella viscosa is a bacterium belonging to the family Moritellaceae and was formerly known as Vibrio viscosus. The name ‘viscosa’ originates from the slimy nature of the bacterium. M. viscosa is considered to be the main causative agent of the phenomenon ‘winter ulcer’ or ‘cold-water ulcer......’ which affects various fish species in seawater during cold periods (Lunder et al. 1995). The bacterium is mainly a problem for farmed salmonid species, such as Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss), but has also been isolated from other fish species, including Atlantic...... market price because of a quality downgrade caused by textural changes in the fillet....

  4. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Science.gov (United States)

    Rhee, Mun Su; Moritz, Brélan E.; Xie, Gary; Glavina del Rio, T.; Dalin, E.; Tice, H.; Bruce, D.; Goodwin, L.; Chertkov, O.; Brettin, T.; Han, C.; Detter, C.; Pitluck, S.; Land, Miriam L.; Patel, Milind; Ou, Mark; Harbrucker, Roberta; Ingram, Lonnie O.; Shanmugam, K. T.

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 °C and pH 5.0 and ferments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 °C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemicellulose. This bacterium is also considered as a potential probiotic. Complete genome sequence of a representative strain, B. coagulans strain 36D1, is presented and discussed. PMID:22675583

  5. Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Studies were conducted to determine the cause of the acute mortality of cage-cultured Epinephelus awoara in the Tong'an Bay of Xiamen, China during the summer of 2002. Predominant bacteria strain TS-628 was isolated from the diseased grouper. The virulence test confirmed that TS-628 was the pathogenic bacterium. Biochemical characteristics of the isolates were determined using the automatic bacterial identification system and standard tube tests. To further confirm the identification, a 1 121 bp 16S rRNA gene sequence of the isolate was amplified by PCR, which had been deposited into Genbank (accession number: AY747308). According to the biochemical characteristics and by comparing the 16S rRNA gene homology of the isolate, the pathogenic bacterium was identified as Vibrio harveyi. Drug sensitivity tests showed that this pathogenic bacterium was sensitive to 16 antibacterials, especially to chloramphenicol and actinospectacin, but completely resistant to antibacterials likes vancomycin, penicillin, lincomycin, and so on.

  6. Halomonas maura is a physiologically versatile bacterium of both ecological and biotechnological interest.

    Science.gov (United States)

    Llamas, Inmaculada; del Moral, Ana; Martínez-Checa, Fernando; Arco, Yolanda; Arias, Soledad; Quesada, Emilia

    2006-01-01

    Halomonas maura is a bacterium of great metabolic versatility. We summarise in this work some of the properties that make it a very interesting microorganism both from an ecological and biotechnological point of view. It plays an active role in the nitrogen cycle, is capable of anaerobic respiration in the presence of nitrate and has recently been identified as a diazotrophic bacterium. Of equal interest is mauran, the exopolysaccharide produced by H. maura, which contributes to the formation of biofilms and thus affords the bacterium advantages in the colonisation of its saline niches. Mauran is highly viscous, shows thixotropic and pseudoplastic behaviour, has the capacity to capture heavy metals and exerts a certain immunomodulator effect in medicine. All these attributes have prompted us to make further investigations into its molecular characteristics. To date we have described 15 open reading frames (ORF's) related to exopolysaccharide production, nitrogen fixation and nitrate reductase activity among others.

  7. Microbial survival of space vacuum and extreme ultraviolet irradiation: strain isolation and analysis during a rocket flight.

    Science.gov (United States)

    Saffary, Roya; Nandakumar, Renu; Spencer, Dennis; Robb, Frank T; Davila, Joseph M; Swartz, Marvin; Ofman, Leon; Thomas, Roger J; DiRuggiero, Jocelyne

    2002-09-24

    We have recovered new isolates from hot springs, in Yellowstone National Park and the Kamchatka Peninsula, after gamma-irradiation and exposure to high vacuum (10(-6) Pa) of the water and sediment samples. The resistance to desiccation and ionizing radiation of one of the isolates, Bacillus sp. strain PS3D, was compared to that of the mesophilic bacterium, Deinococcus radiodurans, a species well known for its extraordinary resistance to desiccation and high doses of ionizing radiation. Survival of these two microorganisms was determined in real and simulated space conditions, including exposure to extreme UV radiation (10-100 nm) during a rocket flight. We found that up to 15 days of desiccation alone had little effect on the viability of either bacterium. In contrast, exposure to space vacuum ( approximately 10(-6) Pa) decreased cell survival by two and four orders of magnitude for Bacillus sp. strain PS3D and D. radiodurans, respectively. Simultaneous exposure to space vacuum and extreme UV radiation further decreased the survival of both organisms, compared to unirradiated controls. This is the first report on the isolated effect of extreme UV at 30 nm on cell survival. Extreme UV can only be transmitted through high vacuum, therefore its penetration into the cells may only be superficial, suggesting that in contrast to near UV, membrane proteins rather than DNA were damaged by the radiation.

  8. Statistical Model of Extreme Shear

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

    2004-01-01

    In order to continue cost-optimisation of modern large wind turbines, it is important to continously increase the knowledge on wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describe the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of high-sampled full-scale time series measurements...... are consistent, given the inevitabel uncertainties associated with model as well as with the extreme value data analysis. Keywords: Statistical model, extreme wind conditions, statistical analysis, turbulence, wind loading, statistical analysis, turbulence, wind loading, wind shear, wind turbines....

  9. Racial Extremism in the Army

    National Research Council Canada - National Science Library

    Hudson, Walter M

    1998-01-01

    ... modem phenomenon of "skinheads." I then discuss the history of white supremacist extremism in the Army, culminating in the December, 1995 murders of two black civilians by soldiers assigned to the 82d Airborne Division at Fort Bragg, North Carolina...

  10. Description of a bacterium associated with redmouth disease of rainbow trout (Salmo gairdneri)

    Science.gov (United States)

    Ross, A.J.; Rucker, R.R.; Ewing, W.H.

    1966-01-01

    A description was given of a gram-negative, peritrichously flagellated, fermentative bacterium that was isolated on numerous occasions from kidney tissues of rainbow trout (Salmo gairdneri) afflicted with redmouth disease. Although the bacteria apparently were members of the family Enterobacteriaceae, it was impossible to determine their taxonomic position within the family with certainty. Hence it was recommended that their taxonomic position remain sub judice for the present. As a temporary designation RM bacterium was used. Redmouth disease was transmitted from infected to normal fish through the medium of water.

  11. From Genome to Function: Systematic Analysis of the Soil Bacterium Bacillus Subtilis

    Science.gov (United States)

    Crawshaw, Samuel G.; Wipat, Anil

    2001-01-01

    Bacillus subtilis is a sporulating Gram-positive bacterium that lives primarily in the soil and associated water sources. Whilst this bacterium has been studied extensively in the laboratory, relatively few studies have been undertaken to study its activity in natural environments. The publication of the B. subtilis genome sequence and subsequent systematic functional analysis programme have provided an opportunity to develop tools for analysing the role and expression of Bacillus genes in situ. In this paper we discuss analytical approaches that are being developed to relate genes to function in environments such as the rhizosphere. PMID:18628943

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

    Directory of Open Access Journals (Sweden)

    Danielle Moinier

    2017-07-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  14. Legacies from extreme drought increase ecosystem sensitivity to future extremes

    Science.gov (United States)

    Smith, M. D.; Knapp, A.; Hoover, D. L.; Avolio, M. L.; Felton, A. J.; Wilcox, K. R.

    2016-12-01

    Climate extremes, such as drought, are increasing in frequency and intensity, and the ecological consequences of these extreme events can be substantial and widespread. Although there is still much to be learned about how ecosystems will respond to an intensification of drought, even less is known about the factors that determine post-drought recovery of ecosystem function. Such knowledge is particularly important because post-drought recovery periods can be protracted depending on the extent to which key plant populations, community structure and biogeochemical processes are affected. These drought legacies may alter ecosystem function for many years post-drought and may impact future sensitivity to climate extremes. We experimentally imposed two extreme growing season droughts in a central US grassland to assess the impacts of repeated droughts on ecosystem resistance (response) and resilience (recovery). We found that this grassland was not resistant to the first extreme drought due to reduced productivity and differential sensitivity of the co-dominant C4 grass (Andropogon gerardii) and C3 forb (Solidago canadensis) species. This differential sensitivity led to a reordering of species abundances within the plant community. Yet, despite this large shift in plant community composition, which persisted post-drought, the grassland was highly resilient post-drought, due to increased abundance of the dominant C4 grass. Because of this shift to increased C4 grass dominance, we expected that previously-droughted grassland would be more resistant to a second extreme drought. However, contrary to these expectations, previously droughted grassland was more sensitive to drought than grassland that had not experienced drought. Thus, our result suggest that legacies of drought (shift in community composition) may increase ecosystem sensitivity to future extreme events.

  15. Global predictability of temperature extremes

    Science.gov (United States)

    Coughlan de Perez, Erin; van Aalst, Maarten; Bischiniotis, Konstantinos; Mason, Simon; Nissan, Hannah; Pappenberger, Florian; Stephens, Elisabeth; Zsoter, Ervin; van den Hurk, Bart

    2018-05-01

    Extreme temperatures are one of the leading causes of death and disease in both developed and developing countries, and heat extremes are projected to rise in many regions. To reduce risk, heatwave plans and cold weather plans have been effectively implemented around the world. However, much of the world’s population is not yet protected by such systems, including many data-scarce but also highly vulnerable regions. In this study, we assess at a global level where such systems have the potential to be effective at reducing risk from temperature extremes, characterizing (1) long-term average occurrence of heatwaves and coldwaves, (2) seasonality of these extremes, and (3) short-term predictability of these extreme events three to ten days in advance. Using both the NOAA and ECMWF weather forecast models, we develop global maps indicating a first approximation of the locations that are likely to benefit from the development of seasonal preparedness plans and/or short-term early warning systems for extreme temperature. The extratropics generally show both short-term skill as well as strong seasonality; in the tropics, most locations do also demonstrate one or both. In fact, almost 5 billion people live in regions that have seasonality and predictability of heatwaves and/or coldwaves. Climate adaptation investments in these regions can take advantage of seasonality and predictability to reduce risks to vulnerable populations.

  16. Methylocella tundrae sp. nov., a novel methanotrophic bacterium from acidic tundra peatlands.

    Science.gov (United States)

    Dedysh, Svetlana N; Berestovskaya, Yulia Y; Vasylieva, Lina V; Belova, Svetlana E; Khmelenina, Valentina N; Suzina, Natalia E; Trotsenko, Yuri A; Liesack, Werner; Zavarzin, George A

    2004-01-01

    A novel species, Methylocella tundrae, is proposed for three methanotrophic strains (T4T, TCh1 and TY1) isolated from acidic Sphagnum tundra peatlands. These strains are aerobic, Gram-negative, non-motile, dinitrogen-fixing rods that possess a soluble methane monooxygenase and utilize the serine pathway for carbon assimilation. Strains T4T, TCh1 and TY1 are moderately acidophilic organisms capable of growth between pH 4.2 and 7.5 (optimum 5.5-6.0) and between 5 and 30 degrees C (optimum 15 degrees C). The major phospholipid fatty acid is 18:1omega7c. The DNA G+C content of strain T4T is 63.3 mol%. The three strains possess almost identical 16S rRNA gene sequences and are most closely related to two previously identified species of Methylocella, Methylocella palustris (97% similarity) and Methylocella silvestris (97.5% similarity). DNA-DNA hybridization values of strain T4T with Methylocella palustris KT and Methylocella silvestris BL2T were respectively 27 and 36%. Thus, the tundra strains represent a novel species, for which the name Methylocella tundrae sp. nov. is proposed. Strain T4T (=DSM 15673T=NCIMB 13949T) is the type strain.

  17. Genome Sequence of Lactobacillus delbrueckii subsp. lactis CNRZ327, a Dairy Bacterium with Anti-Inflammatory Properties.

    Science.gov (United States)

    El Kafsi, Hela; Binesse, Johan; Loux, Valentin; Buratti, Julien; Boudebbouze, Samira; Dervyn, Rozenn; Hammani, Amal; Maguin, Emmanuelle; van de Guchte, Maarten

    2014-07-17

    Lactobacillus delbrueckii subsp. lactis CNRZ327 is a dairy bacterium with anti-inflammatory properties both in vitro and in vivo. Here, we report the genome sequence of this bacterium, which appears to contain no less than 215 insertion sequence (IS) elements, an exceptionally high number regarding the small genome size of the strain. Copyright © 2014 El Kafsi et al.

  18. Study of interaction of the bacterium cupriavidus metallidurans with strontium

    International Nuclear Information System (INIS)

    Boussiga, Rim

    2010-01-01

    Cupriavidus metallidurans strain Ch 34 (previously known as Ralstonia metallidurans, Ralstonia eutropha, and Alcaligenes eutrophus) is an ideal subject to study heavy metal disturbance of cellular processes. Moreover, the capacity of C. metallidurans Ch 34 for in situ bioremediation was assessed and proved to be feasible on pilot scale. In this work, the molecular and physiological response to strontium cations (Sr 2+ ) by C.metallidurans Ch 34 was studied. Results showed that C. metallidurans Ch 34 resisted to high concentrations of Sr (120 m M) and that this resistance is not linked to the presence of its 2 large plasmid pMOL30 or pMOL28. During this study, a tctCBA-dependent tripartite tricarboxylate transport (TTT) system in strain Ch 34 was discovered. Transmission Electron Microscopy (TEM) observation of C.metallidurans challenged with strontium confirms the precipitation of Sr 2+ ) directly onto the surface of cells, inside and in the microenvironment around the cells. These results highlight the potential of C. metalliduras Ch 34 to endure environmental extremes and suggest that in situ bioremediation of Sr-containing waste with Ch 34 might be feasible.

  19. Ideologies and Discourses: Extreme Narratives in Extreme Metal Music

    Directory of Open Access Journals (Sweden)

    Bojana Radovanović

    2016-10-01

    Full Text Available Historically speaking, metal music has always been about provoking a strong reaction. Depending on the characteristics of different sub-genres, one can focus on the sound, technique, visual appearance, and furthermore, the ideologies and ideas that are the foundation for each of the sub-genres. Although the majority of the metal community rejects accusations of being racially intolerant, some ideologies of extreme sub-genres (such as black metal are in fact formed around the ideas of self-conscious elitism expressed through interest in pagan mythology, racism, Nazism and fascism. There has been much interest in the Nazi era within the extreme metal scene thus influencing other sub-genres and artists. The aim of this paper is to examine various appearances of extreme narratives such as Nazism and racism in  different sub-genres of metal, bearing in mind variations dependent on geographical, political, and other factors.

  20. Intestinimonas butyriciproducens gen. nov., sp. nov., a novel butyrate-producing bacterium from the mouse intestine

    NARCIS (Netherlands)

    Kläring, K.; Hanske, L.; Bui, T.P.N.; Charrier, C.; Blaut, M.; Haller, D.; Plugge, C.M.; Clavel, T.

    2013-01-01

    Whilst creating a bacterial collection of strains from the mouse intestine, we isolated a Gram-negative, spore-forming, non-motile and strictly anaerobic rod-shaped bacterium from the caecal content of a TNFdeltaARE mouse. The isolate, referred to as strain SRB-521-5-IT, was originally cultured on a

  1. Draft Genome Sequence of Desulfuromonas acetexigens Strain 2873, a Novel Anode-Respiring Bacterium

    KAUST Repository

    Katuri, Krishna

    2017-03-03

    Here, we report the draft genome sequence of Desulfuromonas acetexigens strain 2873, which was originally isolated from digester sludge from a sewage treatment plant in Germany. This bacterium is capable of anode respiration with high electrochemical activity in microbial electrochemical systems. The draft genome contains 3,376 predicted protein-coding genes and putative multiheme c-type cytochromes.

  2. Design of semi industrial radium separator by a new bacterium MGF-48

    International Nuclear Information System (INIS)

    Ghafourian, H.; Emami, M.R.; Farazmand, A.

    1998-01-01

    Following of a research work which has been recently published in AEOI scientific Bulletin no. 14, a semi industrial bioreactor has been designed for separation of radium using a new bacterium MGF-48. This bioreactor could be utilized for a high rate separation of radium in semi industrial scale. (author)

  3. Thermaerobacter litoralis sp. nov., a strictly aerobic and thermophilic bacterium isolated from a coastal hydrothermal field

    DEFF Research Database (Denmark)

    Tanaka, Reiji; Kawaichi, Satoshi; Nishimura, Hiroshi

    2006-01-01

    A novel thermophilic bacterium, strain KW1T, was isolated from a coastal hydrothermal field on the Satsuma Peninsula, Kagoshima Prefecture, Japan. The variably Gram-stained cells were motile rods with flagella, did not form spores and proliferated at 52-78°C (optimum, 70°C), pH 5-8 (optimum, pH 7...

  4. Flavobacterium nitratireducens sp. nov., an amylolytic bacterium of the family Flavobacteriaceae isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain N1 sup(T), was isolated from a marine water sample collected from the sea shore, Bay of Bengal, Visakhapatnam, India. The strain was positive for starch hydrolysis, nitrate...

  5. Marinobacter nitratireducens sp. nov., a halophilic and lipolytic bacterium isolated from coastal surface sea water

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Korpole, S.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, motile bacterium, designated strain AK21T , was isolated from coastal surface sea water at Visakhapatnam, India. The strain was positive for oxidase, catalase, lipase, L-proline arylamidase...

  6. Aliidiomarina haloalkalitolerans sp. nov., a marine bacterium isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; Nupur; AnilKumar, P.

    A novel Gram-negative, rod shaped, motile, non-sporing strictly aerobic bacterium, designated strain AK5 sup(T), was isolated from a sea water sample collected near Visakhapatnam coast, Bay of Bengal, India. Colonies on marine agar were circular, 3...

  7. Draft Genome Sequence of Advenella kashmirensis Strain W13003, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

    Science.gov (United States)

    Jin, Decai; Zhou, Lisha; Wu, Liang; An, Wei; Zhao, Lin

    2014-01-01

    Advenella kashmirensis strain W13003 is a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated marine sediments. Here, we report the 4.8-Mb draft genome sequence of this strain, which will provide insights into the diversity of A. kashmirensis and the mechanism of PAH degradation in the marine environment. PMID:24482505

  8. Draft Genome Sequence of Desulfuromonas acetexigens Strain 2873, a Novel Anode-Respiring Bacterium

    KAUST Repository

    Katuri, Krishna; Albertsen, Mads; Saikaly, Pascal

    2017-01-01

    Here, we report the draft genome sequence of Desulfuromonas acetexigens strain 2873, which was originally isolated from digester sludge from a sewage treatment plant in Germany. This bacterium is capable of anode respiration with high electrochemical activity in microbial electrochemical systems. The draft genome contains 3,376 predicted protein-coding genes and putative multiheme c-type cytochromes.

  9. Draft Genome Sequence of Lactobacillus paracasei DmW181, a Bacterium Isolated from Wild Drosophila

    OpenAIRE

    Hammer, Austin J.; Walters, Amber; Carroll, Courtney; Newell, Peter D.; Chaston, John M.

    2017-01-01

    ABSTRACT The draft genome sequence of Lactobacillus paracasei DmW181, an anaerobic bacterium isolate from wild Drosophila flies, is reported here. Strain DmW181 possesses genes for sialic acid and mannose metabolism. The assembled genome is 3,201,429?bp, with 3,454 predicted genes.

  10. Draft Genome Sequence of Lactobacillus paracasei DmW181, a Bacterium Isolated from Wild Drosophila.

    Science.gov (United States)

    Hammer, Austin J; Walters, Amber; Carroll, Courtney; Newell, Peter D; Chaston, John M

    2017-07-06

    The draft genome sequence of Lactobacillus paracasei DmW181, an anaerobic bacterium isolate from wild Drosophila flies, is reported here. Strain DmW181 possesses genes for sialic acid and mannose metabolism. The assembled genome is 3,201,429 bp, with 3,454 predicted genes. Copyright © 2017 Hammer et al.

  11. Whole-Genome Sequence of the Purple Photosynthetic Bacterium Rhodovulum sulfidophilum Strain W4

    OpenAIRE

    Masuda, Shinji; Hori, Koichi; Maruyama, Fumito; Ren, Shukun; Sugimoto, Saori; Yamamoto, Nozomi; Mori, Hiroshi; Yamada, Takuji; Sato, Shusei; Tabata, Satoshi; Ohta, Hiroyuki; Kurokawa, Ken

    2013-01-01

    We report the draft genome sequence of the purple photosynthetic bacterium Rhodovulum sulfidophilum. The photosynthesis gene cluster comprises two segments?a unique feature among photosynthesis gene clusters of purple bacteria. The genome information will be useful for further analysis of bacterial photosynthesis.

  12. Draft Genome Sequence of the Efficient Bioflocculant-Producing Bacterium Paenibacillus sp. Strain A9

    Science.gov (United States)

    Liu, Jin-liang; Hu, Xiao-min

    2013-01-01

    Paenibacillus sp. strain A9 is an important bioflocculant-producing bacterium, isolated from a soil sample, and is pale pink-pigmented, aerobic, and Gram-positive. Here, we report the draft genome sequence and the initial findings from a preliminary analysis of strain A9, which is a novel species of Paenibacillus. PMID:23618713

  13. Draft Genome Sequence of Pontibacter sp. nov. BAB1700, a Halotolerant, Industrially Important Bacterium

    Science.gov (United States)

    Joshi, M. N.; Sharma, A. C.; Pandya, R. V.; Patel, R. P.; Saiyed, Z. M.; Saxena, A. K.

    2012-01-01

    Pontibacter sp. nov. BAB1700 is a halotolerant, Gram-negative, rod-shaped, pink-pigmented, menaquinone-7-producing bacterium isolated from sediments of a drilling well. The draft genome sequence of the strain, consisting of one chromosome of 4.5 Mb, revealed vital gene clusters involved in vitamin biosynthesis and resistance against various metals and antibiotics. PMID:23105068

  14. The 2015 Nobel Prize in Physiology or Medicine: A Soil Bacterium ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 4. The 2015 Nobel Prize in Physiology or Medicine: A Soil Bacterium and a Chinese Herb Steal the Show. Pundi N Rangarajan. General Article Volume 21 Issue 4 April 2016 pp 315-326 ...

  15. Exo- and surface proteomes of the probiotic bacterium Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Celebioglu, Hasan Ufuk; Svensson, Birte

    2017-01-01

    Lactobacillus acidophilus NCFM is a well-known probiotic bacterium extensively studied for its beneficial health effects. Exoproteome (proteins exported into culture medium) and surface proteome (proteins attached to S-layer) of this probiotic were identified by using 2DE followed by MALDI TOF MS...

  16. Isolation and Structure Elucidation of a Novel Yellow Pigment from the Marine Bacterium Pseudoalteromonas tunicata

    Directory of Open Access Journals (Sweden)

    N. Kumar

    2005-10-01

    Full Text Available The marine environment is a major source for many novel natural compounds. A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds. The structural identification was achieved by a combination of 1D and 2D-NMR spectroscopy and high resolution mass spectrometry data.

  17. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  18. Oceanospirillum nioense sp. nov., a marine bacterium isolated from sediment sample of Palk bay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.K.; Bhumika, V.; Thomas, M.; AnilKumar, P.; Srinivas, T.N.R.

    A novel Gram-negative, spiral shaped, motile bacterium, designated strain NIO-S6T, was isolated from a sediment sample collected from Offshore Rameswaram, Tamilnadu, India. Strain NIO-S6 sup(T) was found to be positive for oxidase, DNase and lysine...

  19. Genome sequence of the pattern forming Paenibacillus vortex bacterium reveals potential for thriving in complex environments

    NARCIS (Netherlands)

    Sirota-Madi, A.; Olender, T.; Helman, Y.; Ingham, C.; Brainis, I.; Roth, D.; Hagi, E.; Brodsky, L.; Leshkowitz, D.; Galatenko, V.; Nikolaev, V.; Mugasimangalam, R.C.; Bransburg-Zabary, S.; Gutnick, D.L.; Lancet, D.; Ben-Jacob, E.

    2010-01-01

    Background: The pattern-forming bacterium Paenibacillus vortex is notable for its advanced social behavior, which is reflected in development of colonies with highly intricate architectures. Prior to this study, only two other Paenibacillus species (Paenibacillus sp. JDR-2 and Paenibacillus larvae)

  20. Removal of zinc from aqueous solution by metal resistant symbiotic bacterium Mesorhizobium amorphae

    DEFF Research Database (Denmark)

    Hao, Xiuli; Mohamad, Osama Abdalla; Xie, Pin

    2014-01-01

    Biosorption of zinc by living biomasses of metal resistant symbiotic bacterium Mesorhizobium amorphae CCNWGS0123 was investigated under optimal conditions at pH 5.0, initial metal concentrations of 100 mg L-1, and a dose of 1.0 g L-1. M. amorphae exhibited an efficient removal of Zn2+ from aqueous...

  1. Transcriptome analysis of the rhizosphere bacterium Azospirillum brasilense reveals an extensive auxin response.

    Science.gov (United States)

    Van Puyvelde, Sandra; Cloots, Lore; Engelen, Kristof; Das, Frederik; Marchal, Kathleen; Vanderleyden, Jos; Spaepen, Stijn

    2011-05-01

    The rhizosphere bacterium Azospirillum brasilense produces the auxin indole-3-acetic acid (IAA) through the indole-3-pyruvate pathway. As we previously demonstrated that transcription of the indole-3-pyruvate decarboxylase (ipdC) gene is positively regulated by IAA, produced by A. brasilense itself or added exogenously, we performed a microarray analysis to study the overall effects of IAA on the transcriptome of A. brasilense. The transcriptomes of A. brasilense wild-type and the ipdC knockout mutant, both cultured in the absence and presence of exogenously added IAA, were compared.Interfering with the IAA biosynthesis/homeostasis in A. brasilense through inactivation of the ipdC gene or IAA addition results in much broader transcriptional changes than anticipated. Based on the multitude of changes observed by comparing the different transcriptomes, we can conclude that IAA is a signaling molecule in A. brasilense. It appears that the bacterium, when exposed to IAA, adapts itself to the plant rhizosphere, by changing its arsenal of transport proteins and cell surface proteins. A striking example of adaptation to IAA exposure, as happens in the rhizosphere, is the upregulation of a type VI secretion system (T6SS) in the presence of IAA. The T6SS is described as specifically involved in bacterium-eukaryotic host interactions. Additionally, many transcription factors show an altered regulation as well, indicating that the regulatory machinery of the bacterium is changing.

  2. Two-dimensional gel-based alkaline proteome of the probiotic bacterium Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Majumder, Avishek; Cai, Liyang; Ejby, Morten

    2012-01-01

    Lactobacillus acidophilus NCFM (NCFM) is a well‐documented probiotic bacterium isolated from human gut. Detailed 2D gel‐based NCFM proteomics addressed the so‐called alkaline range, i.e., pH 6–11. Proteins were identified in 150 of the 202 spots picked from the Coomassie Brilliant Blue stained 2D...

  3. New recombinant bacterium comprises a heterologous gene encoding glycerol dehydrogenase and/or an up-regulated native gene encoding glycerol dehydrogenase, useful for producing ethanol

    DEFF Research Database (Denmark)

    2010-01-01

    dehydrogenase encoding region of the bacterium, or is inserted into a phosphotransacetylase encoding region of the bacterium, or is inserted into an acetate kinase encoding region of the bacterium. It is operably linked to an inducible, a regulated or a constitutive promoter. The up-regulated glycerol......TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (claimed): Producing recombinant bacterium having enhanced ethanol production characteristics when cultivated in growth medium comprising glycerol comprises: (a) transforming a parental bacterium by (i) the insertion of a heterologous gene encoding...... glycerol dehydrogenase; and/or (ii) up-regulating a native gene encoding glycerol dehydrogenase; and (b) obtaining the recombinant bacterium. Preferred Bacterium: In the recombinant bacterium above, the inserted heterologous gene and/or the up-regulated native gene is encoding a glycerol dehydrogenase...

  4. Seasonal temperature extremes in Potsdam

    Science.gov (United States)

    Kundzewicz, Zbigniew; Huang, Shaochun

    2010-12-01

    The awareness of global warming is well established and results from the observations made on thousands of stations. This paper complements the large-scale results by examining a long time-series of high-quality temperature data from the Secular Meteorological Station in Potsdam, where observation records over the last 117 years, i.e., from January 1893 are available. Tendencies of change in seasonal temperature-related climate extremes are demonstrated. "Cold" extremes have become less frequent and less severe than in the past, while "warm" extremes have become more frequent and more severe. Moreover, the interval of the occurrence of frost has been decreasing, while the interval of the occurrence of hot days has been increasing. However, many changes are not statistically significant, since the variability of temperature indices at the Potsdam station has been very strong.

  5. Lymphoscintigraphy of the lower extremity

    International Nuclear Information System (INIS)

    Abbasi, N.Z.

    1990-01-01

    Fifty one lower extremities of 26 normal healthy volunteers and 26 extremities of 13 patients with oedema have been studied. Dynamic quantitative lymphoscintigraphy using 99Tc-m antimony sulphide colloid during passive exercise as well as before and after active exercise was performed. parameters of lymphatic function including percentage of radioactivity cleared from the injection site, the percentage uptake by the inguinal lymph nodes, the time of arrival of activity at the regional lymph nodes and the lymphatic reserve index have been evaluated. The percentage clearance of activity from the injection site was found technically difficult to standardize and proved to be an unreliable parameter of lymphatic function. However, the quantitation of nodal uptake, the lymphatic transit time and the lymphatic reserve capacity accurately depicted the lymphatic functional status of an individual. The physiologic parameters of lymphatic function of the contralateral lower extremities were compared and a physiologic difference in the lymphatic capacity of the two limbs was scintigraphically documented. (author)

  6. Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium ‘ Candidatus Brocadia sapporoensis’

    KAUST Repository

    Narita, Yuko; Zhang, Lei; Kimura, Zen-ichiro; Ali, Muhammad; Fujii, Takao; Okabe, Satoshi

    2017-01-01

    Anaerobic ammonium-oxidation (anammox) is recognized as an important microbial process in the global nitrogen cycle and wastewater treatment. In this study, we successfully enriched a novel anammox bacterium affiliated with the genus ‘Candidatus Brocadia’ with high purity (>90%) in a membrane bioreactor (MBR). The enriched bacterium was distantly related to the hitherto characterized ‘Ca. Brocadia fulgida’ and ‘Ca. Brocadia sinica’ with 96% and 93% of 16S ribosomal RNA gene sequence identity, respectively. The bacterium exhibited the common structural features of anammox bacteria and the production of hydrazine in the presence of hydroxylamine under anoxic conditions. The temperature range of anammox activity was 20 − 45°C with a maximum activity at 37°C. The maximum specific growth rate (μmax) was determined to be 0.0082h−1 at 37°C, corresponding to a doubling time of 3.5 days. The half-saturation constant (KS) for nitrite was 5±2.5μM. The anammox activity was inhibited by nitrite with 11.6mM representing the 50% inhibitory concentration (IC50) but no significant inhibition was observed in the presence of formate and acetate. The major respiratory quinone was identified to be menaquinone-7 (MK-7). Comparative genome analysis revealed that the anammox bacterium enriched in present study shared nearly half of genes with ‘Ca. Brocadia sinica’ and ‘Ca. Brocadia fulgida’. The bacterium enriched in this study showed all known physiological characteristics of anammox bacteria and can be distinguished from the close relatives by its rRNA gene sequences. Therefore, we proposed the name ‘Ca. Brocadia sapporoensis’ sp. nov.

  7. Isolation, identification, and biocontrol of antagonistic bacterium against Botrytis cinerea after tomato harvest

    Directory of Open Access Journals (Sweden)

    Jun-Feng Shi

    Full Text Available ABSTRACT Tomato is one of the most important vegetables in the world. Decay after harvest is a major issue in the development of tomato industry. Currently, the most effective method for controlling decay after harvest is storage of tomato at low temperature combined with usage of chemical bactericide; however, long-term usage of chemical bactericide not only causes pathogen resistance but also is harmful for human health and environment. Biocontrol method for the management of disease after tomato harvest has great practical significance. In this study, antagonistic bacterium B-6-1 strain was isolated from the surface of tomato and identified as Enterobacter cowanii based on morphological characteristics and physiological and biochemical features combined with sequence analysis of 16SrDNA and ropB gene and construction of dendrogram. Effects of different concentrations of antagonistic bacterium E. cowanii suspension on antifungal activity after tomato harvest were analyzed by mycelium growth rate method. Results revealed that antifungal activity was also enhanced with increasing concentrations of antagonistic bacterium; inhibitory rates of 1 × 105 colony-forming units (cfu/mL antagonistic bacterial solution on Fusarium verticillioides, Alternaria tenuissima, and Botrytis cinerea were 46.31%, 67.48%, and 75.67%, respectively. By using in vivo inoculation method, it was further confirmed that antagonistic bacterium could effectively inhibit the occurrence of B. cinerae after tomato harvest, biocontrol effect of 1 × 109 cfu/mL zymotic fluid reached up to 95.24%, and antagonistic bacterium E. cowanii has biocontrol potential against B. cinerea after harvest of fruits and vegetables.

  8. Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium ‘ Candidatus Brocadia sapporoensis’

    KAUST Repository

    Narita, Yuko

    2017-08-18

    Anaerobic ammonium-oxidation (anammox) is recognized as an important microbial process in the global nitrogen cycle and wastewater treatment. In this study, we successfully enriched a novel anammox bacterium affiliated with the genus ‘Candidatus Brocadia’ with high purity (>90%) in a membrane bioreactor (MBR). The enriched bacterium was distantly related to the hitherto characterized ‘Ca. Brocadia fulgida’ and ‘Ca. Brocadia sinica’ with 96% and 93% of 16S ribosomal RNA gene sequence identity, respectively. The bacterium exhibited the common structural features of anammox bacteria and the production of hydrazine in the presence of hydroxylamine under anoxic conditions. The temperature range of anammox activity was 20 − 45°C with a maximum activity at 37°C. The maximum specific growth rate (μmax) was determined to be 0.0082h−1 at 37°C, corresponding to a doubling time of 3.5 days. The half-saturation constant (KS) for nitrite was 5±2.5μM. The anammox activity was inhibited by nitrite with 11.6mM representing the 50% inhibitory concentration (IC50) but no significant inhibition was observed in the presence of formate and acetate. The major respiratory quinone was identified to be menaquinone-7 (MK-7). Comparative genome analysis revealed that the anammox bacterium enriched in present study shared nearly half of genes with ‘Ca. Brocadia sinica’ and ‘Ca. Brocadia fulgida’. The bacterium enriched in this study showed all known physiological characteristics of anammox bacteria and can be distinguished from the close relatives by its rRNA gene sequences. Therefore, we proposed the name ‘Ca. Brocadia sapporoensis’ sp. nov.

  9. Draft genome of an Aerophobetes bacterium reveals a facultative lifestyle in deep-sea anaerobic sediments

    KAUST Repository

    Wang, Yong

    2016-07-01

    Aerophobetes (or CD12) is a recently defined bacterial phylum, of which the metabolic processes and ecological importance remain unclear. In the present study, we obtained the draft genome of an Aerophobetes bacterium TCS1 from saline sediment near the Thuwal cold seep in the Red Sea using a genome binning method. Analysis of 16S rRNA genes of TCS1 and close relatives revealed wide distribution of Aerophobetes in deep-sea sediments. Phylogenetic relationships showed affinity between Aerophobetes TCS1 and some thermophilic bacterial phyla. The genome of TCS1 (at least 1.27 Mbp) contains a full set of genes encoding core metabolic pathways, including glycolysis and pyruvate fermentation to produce acetyl-CoA and acetate. The identification of cross-membrane sugar transporter genes further indicates its potential ability to consume carbohydrates preserved in the sediment under the microbial mat. Aerophobetes bacterium TCS1 therefore probably carried out saccharolytic and fermentative metabolism. The genes responsible for autotrophic synthesis of acetyl-CoA via the Wood–Ljungdahl pathway were also found in the genome. Phylogenetic study of the essential genes for the Wood–Ljungdahl pathway implied relative independence of Aerophobetes bacterium from the known acetogens and methanogens. Compared with genomes of acetogenic bacteria, Aerophobetes bacterium TCS1 genome lacks the genes involved in nitrogen metabolism, sulfur metabolism, signal transduction and cell motility. The metabolic activities of TCS1 might depend on geochemical conditions such as supplies of CO2, hydrogen and sugars, and therefore the TCS1 might be a facultative bacterium in anaerobic saline sediments near cold seeps. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg.

  10. Statistical Model of Extreme Shear

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Larsen, Gunner Chr.

    2005-01-01

    In order to continue cost-optimisation of modern large wind turbines, it is important to continuously increase the knowledge of wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describes the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of full-scale measurements recorded with a high sampling rate...

  11. Automation Rover for Extreme Environments

    Science.gov (United States)

    Sauder, Jonathan; Hilgemann, Evan; Johnson, Michael; Parness, Aaron; Hall, Jeffrey; Kawata, Jessie; Stack, Kathryn

    2017-01-01

    Almost 2,300 years ago the ancient Greeks built the Antikythera automaton. This purely mechanical computer accurately predicted past and future astronomical events long before electronics existed1. Automata have been credibly used for hundreds of years as computers, art pieces, and clocks. However, in the past several decades automata have become less popular as the capabilities of electronics increased, leaving them an unexplored solution for robotic spacecraft. The Automaton Rover for Extreme Environments (AREE) proposes an exciting paradigm shift from electronics to a fully mechanical system, enabling longitudinal exploration of the most extreme environments within the solar system.

  12. Hygienic diagnosis in extreme conditions

    International Nuclear Information System (INIS)

    Sofronov, G.A.

    1997-01-01

    Review for book by M.P. Zakharchenko, S.A. Lopatin, G.N. Novozhilov, V.I. Zakharov Hygienic diagnosis in extreme conditions is presented discussing the problem of people health preservation under extreme conditions. Hygienic diagnosis is considered illustrated by cases of hostilities (Afghan War), earthquake response in Armenia (1988) and Chernobyl accident response. Attention is paid to the estimation of radiation doses to people and characteristics of main types of dosimeters. The high scientific level of the book is marked

  13. Extreme Conditions Modeling Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

  14. Moving in extreme environments: what's extreme and who decides?

    Science.gov (United States)

    Cotter, James David; Tipton, Michael J

    2014-01-01

    Humans work, rest and play in immensely varied extreme environments. The term 'extreme' typically refers to insufficiency or excess of one or more stressors, such as thermal energy or gravity. Individuals' behavioural and physiological capacity to endure and enjoy such environments varies immensely. Adverse effects of acute exposure to these environments are readily identifiable (e.g. heat stroke or bone fracture), whereas adverse effects of chronic exposure (e.g. stress fractures or osteoporosis) may be as important but much less discernable. Modern societies have increasingly sought to protect people from such stressors and, in that way, minimise their adverse effects. Regulations are thus established, and advice is provided on what is 'acceptable' exposure. Examples include work/rest cycles in the heat, hydration regimes, rates of ascent to and duration of stay at altitude and diving depth. While usually valuable and well intentioned, it is important to realise the breadth and importance of limitations associated with such guidelines. Regulations and advisories leave less room for self-determination, learning and perhaps adaptation. Regulations based on stress (e.g. work/rest cycles relative to WBGT) are more practical but less direct than those based on strain (e.g. core temperature), but even the latter can be substantively limited (e.g. by lack of criterion validation and allowance for behavioural regulation in the research on which they are based). Extreme Physiology & Medicine is publishing a series of reviews aimed at critically examining the issues involved with self- versus regulation-controlled human movement acutely and chronically in extreme environments. These papers, arising from a research symposium in 2013, are about the impact of people engaging in such environments and the effect of rules and guidelines on their safety, enjoyment, autonomy and productivity. The reviews will cover occupational heat stress, sporting heat stress, hydration, diving

  15. Angiography of the upper extremity

    International Nuclear Information System (INIS)

    Janevski, B.K.

    1982-01-01

    This thesis provides a description of the technical and medical aspects of arteriography of the upper extremity and an extensive analysis of the angiographic anatomy and pathology of 750 selective studies performed in more than 500 patients. A short historical review is provided of angiography as a whole and of arteriography of the hand in particular. The method of percutaneous transfemoral catheterization of the arteries of the upper extremity and particularly the arteries of the hand is considered, discussing the problems the angiographer encounters frequently, describing the angiographic complications which may occur and emphasizing the measures to keep them to a minimum. The use of vasodilators in hand angiography is discussed. A short description of the embryological patterns persisting in the arteries of the arm is included in order to understand the congenital variations of the arteries of the upper extremity. The angiographic patterns and clinical aspects of the most common pathological processes involving the arteries of the upper extremities are presented. Special attention is paid to the correlation between angiography and pathology. (Auth.)

  16. Extreme conditions (p, T, H)

    Energy Technology Data Exchange (ETDEWEB)

    Mesot, J [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    The aim of this paper is to summarize the sample environment which will be accessible at the SINQ. In order to illustrate the type of experiments which will be feasible under extreme conditions of temperature, magnetic field and pressure at the SINQ a few selected examples are also given. (author) 7 figs., 14 refs.

  17. Book review: Extreme ocean waves

    Science.gov (United States)

    Geist, Eric L.

    2011-01-01

    ‘‘Extreme Ocean Waves’’ is a collection of ten papers edited by Efim Pelinovsky and Christian Kharif that followed the April 2007 meeting of the General Assembly of the European Geosciences Union. A note on terminology: extreme waves in this volume broadly encompass different types of waves, includ- ing deep-water and shallow-water rogue waves (alternatively termed freak waves), storm surges from cyclones, and internal waves. Other types of waves such as tsunamis or rissaga (meteotsunamis) are not discussed in this volume. It is generally implied that ‘‘extreme’’ has a statistical connotation relative to the average or significant wave height specific to each type of wave. Throughout the book, in fact, the reader will find a combination of theoretical and statistical/ empirical treatment necessary for the complete examination of this subject. In the introduction, the editors underscore the importance of studying extreme waves, documenting several dramatic instances of damaging extreme waves that occurred in 2007. 

  18. Extreme Energy Events Monitoring report

    CERN Document Server

    Baimukhamedova, Nigina

    2015-01-01

    Following paper reflects the progress I made on Summer Student Program within Extreme Energy Events Monitor project I was working on. During 8 week period I managed to build a simple detector system that is capable of triggering events similar to explosions (sudden change in sound levels) and measuring approximate location of the event. Source codes are available upon request and settings described further.

  19. Astrobiology: Life in Extreme Environments

    Science.gov (United States)

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  20. Predicting Structure and Function for Novel Proteins of an Extremophilic Iron Oxidizing Bacterium

    Science.gov (United States)

    Wheeler, K.; Zemla, A.; Banfield, J.; Thelen, M.

    2007-12-01

    Proteins isolated from uncultivated microbial populations represent the functional components of microbial processes and contribute directly to community fitness under natural conditions. Investigations into proteins in the environment are hindered by the lack of genome data, or where available, the high proportion of proteins of unknown function. We have identified thousands of proteins from biofilms in the extremely acidic drainage outflow of an iron mine ecosystem (1). With an extensive genomic and proteomic foundation, we have focused directly on the problem of several hundred proteins of unknown function within this well-defined model system. Here we describe the geobiological insights gained by using a high throughput computational approach for predicting structure and function of 421 novel proteins from the biofilm community. We used a homology based modeling system to compare these proteins to those of known structure (AS2TS) (2). This approach has resulted in the assignment of structures to 360 proteins (85%) and provided functional information for up to 75% of the modeled proteins. Detailed examination of the modeling results enables confident, high-throughput prediction of the roles of many of the novel proteins within the microbial community. For instance, one prediction places a protein in the phosphoenolpyruvate/pyruvate domain superfamily as a carboxylase that fills in a gap in an otherwise complete carbon cycle. Particularly important for a community in such a metal rich environment is the evolution of over 25% of the novel proteins that contain a metal cofactor; of these, one third are likely Fe containing proteins. Two of the most abundant proteins in biofilm samples are unusual c-type cytochromes. Both of these proteins catalyze iron- oxidation, a key metabolic reaction supporting the energy requirements of this community. Structural models of these cytochromes verify our experimental results on heme binding and electron transfer reactivity, and

  1. Nutrition security under extreme events

    Science.gov (United States)

    Martinez, A.

    2017-12-01

    Nutrition security under extreme events. Zero hunger being one of the Sustainable Development Goal from the United Nations, food security has become a trending research topic. However extreme events impact on global food security is not yet 100% understood and there is a lack of comprehension of the underlying mechanisms of global food trade and nutrition security to improve countries resilience to extreme events. In a globalized world, food is still a highly regulated commodity and a strategic resource. A drought happening in a net food-exporter will have little to no effect on its own population but the repercussion on net food-importers can be extreme. In this project, we propose a methodology to describe and quantify the impact of a local drought to human health at a global scale. For this purpose, nutrition supply and global trade data from FAOSTAT have been used with domestic food production from national agencies and FAOSTAT, global precipitation from the Climate Research Unit and health data from the World Health Organization. A modified Herfindahl-Hirschman Index (HHI) has been developed to measure the level of resilience of one country to a drought happening in another country. This index describes how a country is dependent of importation and how diverse are its importation. Losses of production and exportation due to extreme events have been calculated using yield data and a simple food balance at country scale. Results show that countries the most affected by global droughts are the one with the highest dependency to one exporting country. Changes induced by droughts also disturbed their domestic proteins, fat and calories supply resulting most of the time in a higher intake of calories or fat over proteins.

  2. Contribution of eukaryotic microbial communities to the formation of Fe-rich accretions in an extreme acidic environment

    Science.gov (United States)

    Rodrigues, L.; Valente, T.; Correia, A.; Alves, A.; Foing, B.; Davies, G. R.

    2012-04-01

    In the acid mine drainage of Valdarcas, northern Portugal, Fe-rich tubular and spherical macroaccretions are directly associated with the presence of eukaryotic microorganisms. This raises the question whether they are biogenically-derived or the result of an abiotic process mediated by microeukaryotic phototrophs. The drainage water at Valdarcas is characterized by very low pH values (pHhigh metal solubility and presence of iron colloids. Mineralogical analysis (XRD and SEM) of the precipitates indicates a mixture of goethite, schwertmannite and jarosite. Euglenophyta and Chlorophyta acidophilic algal were previously identified in this site. The spatial distribution of Euglena mutabilis indicated that it has a preference to grow up on schwertmannite-rich precipitates. Field observations demonstrate the existence of oxygenated microenvironments created by algal activity suggesting that algae influence iron minerals precipitation, especially schwertmannite. The mineral-microorganism interactions are relevant to understanding this unique and extreme environment. Further investigations regarding the mineralogical and chemical characterization of these deposits, and the identification of microorganisms involved in the process could be helpful to enhance our knowledge of past Fe formations throughout Earth's primordial environment. It is expectable that this information will contribute to establish a framework for recognition of biosignatures on other planets and extraterrestrial bodies. In this study, results on the chemical and mineralogical composition of the structures are presented. The biological context is characterised based on observations made by optical microscopy complemented with molecular data on the microbial communities obtained by culture independent methods. The results are discussed within the context of two models: the studied Fe-rich stromatolites are microeukaryotic-mediated as described by previous workers from similar environments or are the

  3. Increases of heat shock proteins and their mRNAs at high hydrostatic pressure in a deep-sea piezophilic bacterium, Shewanella violacea.

    Science.gov (United States)

    Sato, Hiroshi; Nakasone, Kaoru; Yoshida, Takao; Kato, Chiaki; Maruyama, Tadashi

    2015-07-01

    When non-extremophiles encounter extreme environmental conditions, which are natural for the extremophiles, stress reactions, e.g., expression of heat shock proteins (HSPs), are thought to be induced for survival. To understand how the extremophiles live in such extreme environments, we studied the effects of high hydrostatic pressure on cellular contents of HSPs and their mRNAs during growth in a piezophilic bacterium, Shewanella violacea. HSPs increased at high hydrostatic pressures even when optimal for growth. The mRNAs and proteins of these HSPs significantly increased at higher hydrostatic pressure in S. violacea. In the non-piezophilic Escherichia coli, however, their mRNAs decreased, while their proteins did not change. Several transcriptional start sites (TSSs) for HSP genes were determined by the primer extension method and some of them showed hydrostatic pressure-dependent increase of the mRNAs. A major refolding target of one of the HSPs, chaperonin, at high hydrostatic pressure was shown to be RplB, a subunit of the 50S ribosome. These results suggested that in S. violacea, HSPs play essential roles, e.g., maintaining protein complex machinery including ribosomes, in the growth and viability at high hydrostatic pressure, and that, in their expression, the transcription is under the control of σ(32).

  4. Pediatric lower extremity mower injuries.

    Science.gov (United States)

    Hill, Sean M; Elwood, Eric T

    2011-09-01

    Lawn mower injuries in children represent an unfortunate common problem to the plastic reconstructive surgeon. There are approximately 68,000 per year reported in the United States. Compounding this problem is the fact that a standard treatment algorithm does not exist. This study follows a series of 7 pediatric patients treated for lower extremity mower injuries by a single plastic surgeon. The extent of soft tissue injury varied. All patients were treated with negative pressure wound therapy as a bridge to definitive closure. Of the 7 patients, 4 required skin grafts, 1 required primary closure, 1 underwent a lower extremity amputation secondary to wounds, and 1 was repaired using a cross-leg flap. Function limitations were minimal for all of our patients after reconstruction. Our basic treatment algorithm is presented with initial debridement followed by the simplest method possible for wound closure using negative pressure wound therapy, if necessary.

  5. Extreme Conditions Modeling Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Ryan Geoffrey [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Neary, Vincent Sinclair [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Lawon, Michael J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Lab. (NREL), Golden, CO (United States); Weber, Jochem [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, New Mexico on May 13–14, 2014. The objective of the workshop was to review the current state of knowledge on how to numerically and experimentally model WECs in extreme conditions (e.g. large ocean storms) and to suggest how national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry. More than 30 U.S. and European WEC experts from industry, academia, and national research institutes attended the workshop, which consisted of presentations from W EC developers, invited keynote presentations from subject matter experts, breakout sessions, and a final plenary session .

  6. Extreme project. Progress report 2006

    International Nuclear Information System (INIS)

    Eyrolle, F.; Masson, O.; Charmasson, S.

    2007-01-01

    The E.X.T.R.E.M.E. project introduced in 2005 to the S.E.S.U.R.E. / L.E.R.C.M. has for objectives to acquire data on the consequences of the extreme climatic meteorological episodes on the distribution of the artificial radioisotopes within the various compartments of the geosphere. This report presents the synthesis of the actions developed in 2006 in positioning and in co financing of the project by means of regional or national research programs (C.A.R.M.A., E.X.T.R.E.M.A., E.C.C.O.R.E.V.I.), of data acquisition, valuation and scientific collaboration. (N.C.)

  7. On causality of extreme events

    Directory of Open Access Journals (Sweden)

    Massimiliano Zanin

    2016-06-01

    Full Text Available Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available.

  8. Extreme Nonlinear Optics An Introduction

    CERN Document Server

    Wegener, Martin

    2005-01-01

    Following the birth of the laser in 1960, the field of "nonlinear optics" rapidly emerged. Today, laser intensities and pulse durations are readily available, for which the concepts and approximations of traditional nonlinear optics no longer apply. In this regime of "extreme nonlinear optics," a large variety of novel and unusual effects arise, for example frequency doubling in inversion symmetric materials or high-harmonic generation in gases, which can lead to attosecond electromagnetic pulses or pulse trains. Other examples of "extreme nonlinear optics" cover diverse areas such as solid-state physics, atomic physics, relativistic free electrons in a vacuum and even the vacuum itself. This book starts with an introduction to the field based primarily on extensions of two famous textbook examples, namely the Lorentz oscillator model and the Drude model. Here the level of sophistication should be accessible to any undergraduate physics student. Many graphical illustrations and examples are given. The followi...

  9. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  10. The atherogenic bacterium Porphyromonas gingivalis evades circulating phagocytes by adhering to erythrocytes

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Damgaard, Christian

    2011-01-01

    A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows...... the bacterium to adhere to human red blood cells (RBCs) and thereby evade attack by circulating phagocytes. On incubation with normal human serum, the P. gingivalis strain efficiently fixed complement component 3 (C3). Incubation of bacteria with washed whole blood cells suspended in autologous serum resulted...... in a dose- and time-dependent adherence to RBCs. The adherence required functionally intact complement receptor 1 (CR1; also called CD35) on the RBCs and significantly inhibited the uptake of P. gingivalis by neutrophils and B cells within 1 min of incubation (by 64% and 51%, respectively...

  11. Framing in the Spanish press about the health crisis because of the E. coli bacterium

    Directory of Open Access Journals (Sweden)

    Paloma López Villafranca

    2013-12-01

    Full Text Available This research article analyses  the approach made by press media and other institutional advertising about the E. coli bacterium, most commonly known as cucumber crisis in Spain. While in the rest of Europe this crisis receives the same treatment as A Flu or mad cow disease in this country it is treated as a crisis that affects to the spanish economy and not to the health of the citizen. Economic interests prevail over public health and this is due to official information given. An analysis of contents of the most popular journals in Spain, according to OJD, is made to prove this hypothesis, El Pais, El Mundo and ABC, as well as a study of the main institutional advertising made about E. coli bacterium by official spanish organizations and the media.

  12. Mitigation of membrane biofouling by a quorum quenching bacterium for membrane bioreactors.

    Science.gov (United States)

    Ham, So-Young; Kim, Han-Shin; Cha, Eunji; Park, Jeong-Hoon; Park, Hee-Deung

    2018-06-01

    In this study, a quorum-quenching (QQ) bacterium named HEMM-1 was isolated at a membrane bioreactor (MBR) plant. HEMM-1 has diplococcal morphology and 99% sequence identity to Enterococcus species. The HEMM-1 cell-free supernatant (CFS) showed higher QQ activities than the CFS of other QQ bacteria, mostly by degrading N-acyl homoserine lactones (AHLs) with short acyl chains. Instrumental analyses revealed that HEMM-1 CFS degraded AHLs via lactonase activity. Under static, flow, and shear conditions, the HEMM-1 CFS was effective in reducing bacterial and activated-sludge biofilms formed on membrane surfaces. In conclusion, the HEMM-1 isolate is a QQ bacterium applicable to the control of biofouling in MBRs via inhibition of biofilm formation on membrane surfaces. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Single-bacterium nanomechanics in biomedicine: unravelling the dynamics of bacterial cells

    International Nuclear Information System (INIS)

    Aguayo, S; Bozec, L; Donos, N; Spratt, D

    2015-01-01

    The use of the atomic force microscope (AFM) in microbiology has progressed significantly throughout the years since its first application as a high-resolution imaging instrument. Modern AFM setups are capable of characterizing the nanomechanical behaviour of bacterial cells at both the cellular and molecular levels, where elastic properties and adhesion forces of single bacterium cells can be examined under different experimental conditions. Considering that bacterial and biofilm-mediated infections continue to challenge the biomedical field, it is important to understand the biophysical events leading towards bacterial adhesion and colonization on both biological and non-biological substrates. The purpose of this review is to present the latest findings concerning the field of single-bacterium nanomechanics, and discuss future trends and applications of nanoindentation and single-cell force spectroscopy techniques in biomedicine. (topical review)

  14. Promoting Exit from Violent Extremism

    DEFF Research Database (Denmark)

    Dalgaard-Nielsen, Anja

    2013-01-01

    A number of Western countries are currently adding exit programs targeting militant Islamists to their counterterrorism efforts. Drawing on research into voluntary exit from violent extremism, this article identifies themes and issues that seem to cause doubt, leading to exit. It then provides a ...... the influence attempt as subtle as possible, use narratives and self-affirmatory strategies to reduce resistance to persuasion, and consider the possibility to promote attitudinal change via behavioral change as an alternative to seek to influence beliefs directly....

  15. Racial Extremism in the Army

    Science.gov (United States)

    1998-04-01

    of Deference ...................................................................................................... 46 1. The Separation of Powers Doctrine...to the military. This deference has a two-fold basis. First, the separation of powers in the U.S. Constitution gives authority to the executive (and...Why should there be judicial deference to the Army’s policy on extremism? There are two principal reasons. First, the Constitution’s separation of powers doctrine

  16. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2016-12-01

    LM, de Crombrugghe B. Some recent advances in the chemistry and biology of trans- forming growth factor-beta. J Cell Biol 1987;105:1039e45. 12. Hao Y...SUPPLEMENTARY NOTES 14. ABSTRACT In current war trauma, 20-30% of all extremity injuries and >80% of penetrating injuries being associated with peripheral nerve...through both axonal advance and in revascularization of the graft following placement. We are confident that this technology may allow us to

  17. Technology improves upper extremity rehabilitation.

    Science.gov (United States)

    Kowalczewski, Jan; Prochazka, Arthur

    2011-01-01

    Stroke survivors with hemiparesis and spinal cord injury (SCI) survivors with tetraplegia find it difficult or impossible to perform many activities of daily life. There is growing evidence that intensive exercise therapy, especially when supplemented with functional electrical stimulation (FES), can improve upper extremity function, but delivering the treatment can be costly, particularly after recipients leave rehabilitation facilities. Recently, there has been a growing level of interest among researchers and healthcare policymakers to deliver upper extremity treatments to people in their homes using in-home teletherapy (IHT). The few studies that have been carried out so far have encountered a variety of logistical and technical problems, not least the difficulty of conducting properly controlled and blinded protocols that satisfy the requirements of high-level evidence-based research. In most cases, the equipment and communications technology were not designed for individuals with upper extremity disability. It is clear that exercise therapy combined with interventions such as FES, supervised over the Internet, will soon be adopted worldwide in one form or another. Therefore it is timely that researchers, clinicians, and healthcare planners interested in assessing IHT be aware of the pros and cons of the new technology and the factors involved in designing appropriate studies of it. It is crucial to understand the technical barriers, the role of telesupervisors, the motor improvements that participants can reasonably expect and the process of optimizing IHT-exercise therapy protocols to maximize the benefits of the emerging technology. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Typologies of extreme longevity myths.

    Science.gov (United States)

    Young, Robert D; Desjardins, Bertrand; McLaughlin, Kirsten; Poulain, Michel; Perls, Thomas T

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980-2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

  19. Moderate and extreme maternal obesity.

    LENUS (Irish Health Repository)

    Abdelmaboud, M O

    2012-05-01

    The aim of this study was to investigate the prevalence of moderate and extreme obesity among an Irish obstetric population over a 10-year period, and to evaluate the obstetric features of such pregnancies. Of 31,869 women delivered during the years 2000-2009, there were 306 women in the study group, including 173 in the moderate or Class 2 obese category (BMI 35-39.9) and 133 in the extreme or Class 3 obese category (BMI > or = 40).The prevalence of obese women with BMI > or = 35 was 9.6 per 1000 (0.96%), with an upward trend observed from 2.1 per 1000 in the year 2000, to 11.8 per 1000 in the year 2009 (P = 0.001). There was an increase in emergency caesarean section (EMCS) risk for primigravida versus multigravid women, within both obese categories (P < 0.001). However, there was no significant difference in EMCS rates observed between Class 2 and Class 3 obese women, when matched for parity. The prevalence of moderate and extreme obesity reported in this population is high, and appears to be increasing. The increased rates of abdominal delivery, and the levels of associated morbidity observed, have serious implications for such women embarking on pregnancy.

  20. Attribution of climate extreme events

    Science.gov (United States)

    Trenberth, Kevin E.; Fasullo, John T.; Shepherd, Theodore G.

    2015-08-01

    There is a tremendous desire to attribute causes to weather and climate events that is often challenging from a physical standpoint. Headlines attributing an event solely to either human-induced climate change or natural variability can be misleading when both are invariably in play. The conventional attribution framework struggles with dynamically driven extremes because of the small signal-to-noise ratios and often uncertain nature of the forced changes. Here, we suggest that a different framing is desirable, which asks why such extremes unfold the way they do. Specifically, we suggest that it is more useful to regard the extreme circulation regime or weather event as being largely unaffected by climate change, and question whether known changes in the climate system's thermodynamic state affected the impact of the particular event. Some examples briefly illustrated include 'snowmaggedon' in February 2010, superstorm Sandy in October 2012 and supertyphoon Haiyan in November 2013, and, in more detail, the Boulder floods of September 2013, all of which were influenced by high sea surface temperatures that had a discernible human component.

  1. Typologies of Extreme Longevity Myths

    Directory of Open Access Journals (Sweden)

    Robert D. Young

    2010-01-01

    Full Text Available Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance, Shangri-La Myth (geographic, Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

  2. Five new amicoumacins isolated from a marine-derived Bacterium bacillus subtilis

    KAUST Repository

    Li, Yongxin; Xu, Ying; Liu, Lingli; Han, Zhuang; Lai, Pok Yui; Guo, Xiangrong; Zhang, Xixiang; Lin, Wenhan; Qian, Pei-Yuan

    2012-01-01

    Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature. 2012 by the authors; licensee MDPI.

  3. Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

    KAUST Repository

    Harjes, Janno; Ryu, Tae Woo; Abdelmohsen, Usama Ramadan; Moitinho-Silva, Lucas; Horn, Hannes; Ravasi, Timothy; Hentschel, Ute

    2014-01-01

    The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

  4. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    KAUST Repository

    Haroon, Mohamed; Thompson, Luke R.; Stingl, Ulrich

    2016-01-01

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

  5. Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

    KAUST Repository

    Harjes, Janno

    2014-03-06

    The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

  6. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    KAUST Repository

    Haroon, Mohamed

    2016-02-11

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

  7. Genomic Analysis of Caldithrix abyssi, the Thermophilic Anaerobic Bacterium of the Novel Bacterial Phylum Calditrichaeota

    OpenAIRE

    Kublanov, Ilya V.; Sigalova, Olga M.; Gavrilov, Sergey N.; Lebedinsky, Alexander V.; Rinke, Christian; Kovaleva, Olga; Chernyh, Nikolai A.; Ivanova, Natalia; Daum, Chris; Reddy, T.B.K.; Klenk, Hans-Peter; Spring, Stefan; G?ker, Markus; Reva, Oleg N.; Miroshnichenko, Margarita L.

    2017-01-01

    © 2017 Kublanov, Sigalova, Gavrilov, Lebedinsky, Rinke, Kovaleva, Chernyh, Ivanova, Daum, Reddy, Klenk, Spring, Göker, Reva, Miroshnichenko, Kyrpides, Woyke, Gelfand, Bonch-Osmolovskaya. The genome of Caldithrix abyssi, the first cultivated representative of a phylum-level bacterial lineage, was sequenced within the framework of Genomic Encyclopedia of Bacteria and Archaea (GEBA) project. The genomic analysis revealed mechanisms allowing this anaerobic bacterium to ferment peptides or to impl...

  8. Permanent draft genome of the malachite-green-tolerant bacterium Rhizobium sp. MGL06.

    Science.gov (United States)

    Liu, Yang; Wang, Runping; Zeng, Runying

    2014-12-01

    Rhizobium sp. MGL06, the first Rhizobium isolate from a marine environment, is a malachite-green-tolerant bacterium with a broader salinity tolerance (range: 0.5% to 9%) than other rhizobia. This study sequences and annotates the draft genome sequence of this strain. Genome sequence information provides a basis for analyzing the malachite green tolerance, broad salinity adaptation, nitrogen fixation properties, and taxonomic classification of the isolate. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Five new amicoumacins isolated from a marine-derived Bacterium bacillus subtilis

    KAUST Repository

    Li, Yongxin

    2012-02-03

    Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature. 2012 by the authors; licensee MDPI.

  10. Alteration of the Canine Small-Intestinal Lactic Acid Bacterium Microbiota by Feeding of Potential Probiotics

    OpenAIRE

    Manninen, Titta J. K.; Rinkinen, Minna L.; Beasley, Shea S.; Saris, Per E. J.

    2006-01-01

    Five potentially probiotic canine fecal lactic acid bacterium (LAB) strains, Lactobacillus fermentum LAB8, Lactobacillus salivarius LAB9, Weissella confusa LAB10, Lactobacillus rhamnosus LAB11, and Lactobacillus mucosae LAB12, were fed to five permanently fistulated beagles for 7 days. The survival of the strains and their potential effects on the indigenous intestinal LAB microbiota were monitored for 17 days. Denaturing gradient gel electrophoresis (DGGE) demonstrated that the five fed LAB ...

  11. Comment on "A bacterium that degrades and assimilates poly(ethylene terephthalate)".

    Science.gov (United States)

    Yang, Yu; Yang, Jun; Jiang, Lei

    2016-08-19

    Yoshida et al (Report, 11 March 2016, p. 1196) reported that the bacterium Ideonella sakaiensis 201-F6 can degrade and assimilate poly(ethylene terephthalate) (PET). However, the authors exaggerated degradation efficiency using a low-crystallinity PET and presented no straightforward experiments to verify depolymerization and assimilation of PET. Thus, the authors' conclusions are rather misleading. Copyright © 2016, American Association for the Advancement of Science.

  12. Two New Cholic Acid Derivatives from the Marine Ascidian-Associated Bacterium Hasllibacter halocynthiae

    Directory of Open Access Journals (Sweden)

    Sung Hun Kim

    2012-10-01

    Full Text Available The investigation of secondary metabolites in liquid cultures of a recently discovered marine bacterium, Hasllibacter halocynthiae strain KME 002T, led to the isolation of two new cholic acid derivatives. The structures of these compounds were determined to be 3,3,12-trihydroxy-7-ketocholanic acid (1 and 3,3,12-trihydroxy-7-deoxycholanic acid (2 through HRFABMS and NMR data analyses.

  13. Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium

    OpenAIRE

    Arif, Mohammad; Busot, Grethel Y.; Mann, Rachel; Rodoni, Brendan; Liu, Sanzhen; Stack, James P.

    2016-01-01

    Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of...

  14. A unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium

    OpenAIRE

    Hoshi, Ayaka; Oshima, Kenro; Kakizawa, Shigeyuki; Ishii, Yoshiko; Ozeki, Johji; Hashimoto, Masayoshi; Komatsu, Ken; Kagiwada, Satoshi; Yamaji, Yasuyuki; Namba, Shigetou

    2009-01-01

    One of the most important themes in agricultural science is the identification of virulence factors involved in plant disease. Here, we show that a single virulence factor, tengu-su inducer (TENGU), induces witches' broom and dwarfism and is a small secreted protein of the plant-pathogenic bacterium, phytoplasma. When tengu was expressed in Nicotiana benthamiana plants, these plants showed symptoms of witches' broom and dwarfism, which are typical of phytoplasma infection. Transgenic Arabidop...

  15. Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

    Science.gov (United States)

    Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

    1997-06-01

    The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

  16. The Purine-Utilizing Bacterium Clostridium acidurici 9a: A Genome-Guided Metabolic Reconsideration

    OpenAIRE

    Hartwich, Katrin; Poehlein, Anja; Daniel, Rolf

    2012-01-01

    Clostridium acidurici is an anaerobic, homoacetogenic bacterium, which is able to use purines such as uric acid as sole carbon, nitrogen, and energy source. Together with the two other known purinolytic clostridia C. cylindrosporum and C. purinilyticum, C. acidurici serves as a model organism for investigation of purine fermentation. Here, we present the first complete sequence and analysis of a genome derived from a purinolytic Clostridium. The genome of C. acidurici 9a consists ...

  17. Sexual transmission of a plant pathogenic bacterium, Candidatus Liberibacter asiaticus, between conspecific insect vectors during mating.

    Directory of Open Access Journals (Sweden)

    Rajinder S Mann

    Full Text Available Candidatus Liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae. The bacterium is the presumed causal agent of huanglongbing (HLB, one of the most destructive and economically important diseases of citrus. We investigated whether Las is transmitted between infected and uninfected D. citri adults during courtship. Our results indicate that Las was sexually transmitted from Las-infected male D. citri to uninfected females at a low rate (<4% during mating. Sexual transmission was not observed following mating of infected females and uninfected males or among adult pairs of the same sex. Las was detected in genitalia of both sexes and also in eggs of infected females. A latent period of 7 days or more was required to detect the bacterium in recipient females. Rod shaped as well as spherical structures resembling Las were observed in ovaries of Las-infected females with transmission electron microscopy, but were absent in ovaries from uninfected D. citri females. The size of the rod shaped structures varied from 0.39 to 0.67 µm in length and 0.19 to 0.39 µm in width. The spherical structures measured from 0.61 to 0.80 µm in diameter. This investigation provides convincing evidence that a plant pathogenic bacterium is sexually transmitted from male to female insects during courtship and established evidence that bacteria persist in reproductive organs. Moreover, these findings provide an alternative sexually horizontal mechanism for the spread of Las within populations of D. citri, even in the absence of infected host trees.

  18. Multiple cellobiohydrolases and cellobiose phosphorylases cooperate in the ruminal bacterium Ruminococcus albus 8 to degrade cellooligosaccharides.

    Science.gov (United States)

    Devendran, Saravanan; Abdel-Hamid, Ahmed M; Evans, Anton F; Iakiviak, Michael; Kwon, In Hyuk; Mackie, Roderick I; Cann, Isaac

    2016-10-17

    Digestion of plant cell wall polysaccharides is important in energy capture in the gastrointestinal tract of many herbivorous and omnivorous mammals, including humans and ruminants. The members of the genus Ruminococcus are found in both the ruminant and human gastrointestinal tract, where they show versatility in degrading both hemicellulose and cellulose. The available genome sequence of Ruminococcus albus 8, a common inhabitant of the cow rumen, alludes to a bacterium well-endowed with genes that target degradation of various plant cell wall components. The mechanisms by which R. albus 8 employs to degrade these recalcitrant materials are, however, not clearly understood. In this report, we demonstrate that R. albus 8 elaborates multiple cellobiohydrolases with multi-modular architectures that overall enhance the catalytic activity and versatility of the enzymes. Furthermore, our analyses show that two cellobiose phosphorylases encoded by R. albus 8 can function synergistically with a cognate cellobiohydrolase and endoglucanase to completely release, from a cellulosic substrate, glucose which can then be fermented by the bacterium for production of energy and cellular building blocks. We further use transcriptomic analysis to confirm the over-expression of the biochemically characterized enzymes during growth of the bacterium on cellulosic substrates compared to cellobiose.

  19. FtsZ from radiation resistant bacterium Deinococcus radiodurans is different from its characterized homologues

    International Nuclear Information System (INIS)

    Mehta, Kruti P.; Misra, H.S.

    2012-01-01

    Polymerization/depolymerization dynamics of FtsZ and its GTPase activity are interdependent and the regulation of these processes determines the growth rate in a bacterium. Deinococcus radiodurans R1 that is best known for its extraordinary radiation resistance and efficient DNA double strand break repair is a comparatively slow growing bacterium and its growth gets arrested in response to gamma radiation. Mechanisms of cell division and its regulation under gamma stressed growth condition would be worth investigating. Genome of this bacterium encodes at least all the known components of divisome. Recombinant FtsZ of D. radiodurans (drFtsZ) preferred Mg 2+ for its GTPase activity. Relatively a very low GTPase activity was observed in presence of Mn 2+ , Co 2+ and Ni 2+ while release of inorganic phosphate could not be detected in presence of other divalent ions including Ca 2+ . GTPase activity of drFtsZ was lower than E. coli but higher than Mycobacterium and it required both Mg 2+ and GTP for its polymerization. Its GTPase activity did not increase with increasing concentration of Mg 2+ and correlates with the bundling of protofilaments. Results obtained from transmission electron microscopy and sedimentation analysis supported the reciprocal correlation of polymerization/depolymerization with the levels of GTPase activity. Dynamic light scattering in presence of 5mM or higher concentration of Mg 2+ and Mn 2 showed a characteristic cyclic change in light scattering without addition of extra metal ion or GTP

  20. Antimicrobial polyketide furanoterpenoids from seaweed-associated heterotrophic bacterium Bacillus subtilis MTCC 10403.

    Science.gov (United States)

    Chakraborty, Kajal; Thilakan, Bini; Raola, Vamshi Krishna

    2017-10-01

    Brown seaweed Anthophycus longifolius (Turner) Kützing (family Sargassaceae) associated heterotrophic bacterium Bacillus subtilis MTCC 10403 was found to be a potent isolate with broad range of antibacterial activity against important perceptive food pathogens Vibrio parahaemolyticus, V. vulnificus, and Aeromonas hydrophila. This bacterium was positive for polyketide synthetase gene (KC589397), and therefore, was selected to bioprospect specialized metabolites bearing polyketide backbone. Bioactivity-guided chromatographic fractionation of the ethyl acetate extract of the seaweed-associated bacterium segregated four homologous polyketide furanoterpenoids with potential antibacterial activities against clinically important pathogens. The minimum inhibitory concentration (MIC) assay showed that the referral antibiotics tetracycline and ampicillin were active at 25 μg/mL against the test pathogens, whereas the previously undescribed (4E)-methyl 13-((16-(furan-2-yl) ethyl)-octahydro-7-hydroxy-4-((E)-23-methylbut-21-enyl)-2H-chromen-6-yl)-4-methylpent-4-enoate (compound 1) and methyl 3-(hexahydro-9-((E)-3-methylpent-1-enyl)-4H-furo[3,2-g]isochromen-6-yl) propanoate (compound 3) displayed antibacterial activities against the test pathogens at a lesser concentration (MIC subtilis MTCC 10403 demonstrated to represent a potential source of antimicrobial polyketides for pharmaceutical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes. Final Report

    International Nuclear Information System (INIS)

    Lidstrom, Mary E.

    2003-01-01

    Aqueous mixed low level wastes (MLLW) containing radionuclides, solvents, and/or heavy metals represent a serious current and future problem for DOE environmental management and cleanup. In order to provide low-cost treatment alternatives under mild conditions for such contained wastes, we have proposed to use the radiation-resistant bacterium, Deinococcus radiodurans. This project has focused on developing D. radiodurans strains for dual purpose processes: cometabolic treatment of haloorganics and other solvents and removal of heavy metals from waste streams in an above-ground reactor system. The characteristics of effective treatment strains that must be attained are: (a) high biodegradative and metal binding activity; (b) stable treatment characteristics in the absence of selection and in the presence of physiological stress; (c) survival and activity under harsh chemical conditions, including radiation. The result of this project has been a suite of strains with high biodegradative capabilities that are candidates for pilot stage treatment systems. In addition, we have determined how to create conditions to precipitate heavy metals on the surface of the bacterium, as the first step towards creating dual-use treatment strains for contained mixed wastes of importance to the DOE. Finally, we have analyzed stress response in this bacterium, to create the foundation for developing treatment processes that maximize degradation while optimizing survival under high stress conditions

  2. Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

    Science.gov (United States)

    Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

    2014-01-01

    A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

  3. The effect of Pseudoxanthomonas sp. as manganese oxidizing bacterium on the corrosion behavior of carbon steel

    International Nuclear Information System (INIS)

    Ashassi-Sorkhabi, H.; Moradi-Haghighi, M.; Zarrini, G.

    2012-01-01

    The present study investigated the role of manganese oxidizing bacterium (MOB), namely Pseudoxanthomonas sp. on the corrosion behavior of carbon steel. This bacterium was isolated from sewage treatment plants and identified by biochemical and molecular methods. The electrochemical techniques such as open circuit potentiometry, electrochemical impedance spectroscopy, potentiodynamic and cyclic polarization were used to measure the corrosion rate and observe the corrosion mechanism. Also, scanning electron microscopy and X-ray diffraction studies were applied to surface analysis. This study revealed the strong adhesion of the biofilm on the metal surface in the presence of Pseudoxanthomonas sp. that enhanced the corrosion of carbon steel. X-ray diffraction patterns identified a high content of MnO 2 deposition within these biofilms. This is the first report that discloses the involvement of Pseudoxanthomonas sp. as manganese oxidizing bacteria on the corrosion of carbon steel. - Highlights: ► A new type of manganese oxidizing bacteria, namely Pseudoxanthomonas sp. was indicated. ► This bacterium can create a biofilm on the part of metal surface and affect localized corrosion. ► In the presence of biofilm, the diffusion of oxygen vacancies and manganese ions has occurred.

  4. Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5

    Science.gov (United States)

    Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

    2014-01-01

    Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418

  5. Chitin Degradation Proteins Produced by the Marine Bacterium Vibrio harveyi Growing on Different Forms of Chitin.

    Science.gov (United States)

    Svitil, A L; Chadhain, S; Moore, J A; Kirchman, D L

    1997-02-01

    Relatively little is known about the number, diversity, and function of chitinases produced by bacteria, even though chitin is one of the most abundant polymers in nature. Because of the importance of chitin, especially in marine environments, we examined chitin-degrading proteins in the marine bacterium Vibrio harveyi. This bacterium had a higher growth rate and more chitinase activity when grown on (beta)-chitin (isolated from squid pen) than on (alpha)-chitin (isolated from snow crab), probably because of the more open structure of (beta)-chitin. When exposed to different types of chitin, V. harveyi excreted several chitin-degrading proteins into the culture media. Some chitinases were present with all of the tested chitins, while others were unique to a particular chitin. We cloned and identified six separate chitinase genes from V. harveyi. These chitinases appear to be unique based on DNA restriction patterns, immunological data, and enzyme activity. This marine bacterium and probably others appear to synthesize separate chitinases for efficient utilization of different forms of chitin and chitin by-products.

  6. The effect of Pseudoxanthomonas sp. as manganese oxidizing bacterium on the corrosion behavior of carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Ashassi-Sorkhabi, H., E-mail: habib_ashassi@yahoo.com [Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Moradi-Haghighi, M. [Electrochemistry Research Laboratory, Physical Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Zarrini, G. [Microbiology laboratory, Biology Department, Science Faculty, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2012-02-01

    The present study investigated the role of manganese oxidizing bacterium (MOB), namely Pseudoxanthomonas sp. on the corrosion behavior of carbon steel. This bacterium was isolated from sewage treatment plants and identified by biochemical and molecular methods. The electrochemical techniques such as open circuit potentiometry, electrochemical impedance spectroscopy, potentiodynamic and cyclic polarization were used to measure the corrosion rate and observe the corrosion mechanism. Also, scanning electron microscopy and X-ray diffraction studies were applied to surface analysis. This study revealed the strong adhesion of the biofilm on the metal surface in the presence of Pseudoxanthomonas sp. that enhanced the corrosion of carbon steel. X-ray diffraction patterns identified a high content of MnO{sub 2} deposition within these biofilms. This is the first report that discloses the involvement of Pseudoxanthomonas sp. as manganese oxidizing bacteria on the corrosion of carbon steel. - Highlights: Black-Right-Pointing-Pointer A new type of manganese oxidizing bacteria, namely Pseudoxanthomonas sp. was indicated. Black-Right-Pointing-Pointer This bacterium can create a biofilm on the part of metal surface and affect localized corrosion. Black-Right-Pointing-Pointer In the presence of biofilm, the diffusion of oxygen vacancies and manganese ions has occurred.

  7. Genomic Analysis of a Marine Bacterium: Bioinformatics for Comparison, Evaluation, and Interpretation of DNA Sequences

    Directory of Open Access Journals (Sweden)

    Bhagwan N. Rekadwad

    2016-01-01

    Full Text Available A total of five highly related strains of an unidentified marine bacterium were analyzed through their short genome sequences (AM260709–AM260713. Genome-to-Genome Distance (GGDC showed high similarity to Pseudoalteromonas haloplanktis (X67024. The generated unique Quick Response (QR codes indicated no identity to other microbial species or gene sequences. Chaos Game Representation (CGR showed the number of bases concentrated in the area. Guanine residues were highest in number followed by cytosine. Frequency of Chaos Game Representation (FCGR indicated that CC and GG blocks have higher frequency in the sequence from the evaluated marine bacterium strains. Maximum GC content for the marine bacterium strains ranged 53-54%. The use of QR codes, CGR, FCGR, and GC dataset helped in identifying and interpreting short genome sequences from specific isolates. A phylogenetic tree was constructed with the bootstrap test (1000 replicates using MEGA6 software. Principal Component Analysis (PCA was carried out using EMBL-EBI MUSCLE program. Thus, generated genomic data are of great assistance for hierarchical classification in Bacterial Systematics which combined with phenotypic features represents a basic procedure for a polyphasic approach on unambiguous bacterial isolate taxonomic classification.

  8. Prospect for extreme field science

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, T. [Ludwig Maximilian Univ. and Max Planck Institute for Quantum Optics, Garching (Germany); Japan Atomic Energy Agency, Kyoto and KEK, Tsukuba (Japan)

    2009-11-15

    The kind of laser extreme light infrastructure (ELI) provides will usher in a class of experiments we have only dreamed of for years. The characteristics that ELI brings in include: the highest intensity ever, large fluence, and relatively high repetition rate. A personal view of the author on the prospect of harnessing this unprecedented opportunity for advancing science of extreme fields is presented. The first characteristic of ELI, its intensity, will allow us to access, as many have stressed already, extreme fields that hover around the Schwinger field or at the very least the neighboring fields in which vacuum begins to behave as a nonlinear medium. In this sense, we are seriously probing the 'material' property of vacuum and thus the property that theory of relativity itself described and will entail. We will probe both special theory and general theory of relativity in regimes that have been never tested so far. We may see a glimpse into the reach of relativity or even its breakdown in some extreme regimes. We will learn Einstein and may even go beyond Einstein, if our journey is led. Laser-driven acceleration both by the laser field itself and by the wakefield that is triggered in a plasma is huge. Energies, if not luminosity, we can access, may be unprecedented going far beyond TeV. The nice thing about ELI is that it has relatively high repetition rate and average fluence as compared with other extreme lasers. This high fluence can be a key element that leads to applications to high energy physics, such as gamma-gamma collider driver experiment, and some gamma ray experiments that may be relevant in the frontier of photo-nuclear physics, and atomic energy applications. Needless to say, high fluence is one of most important features that industrial and medical applications may need. If we are lucky, we may see a door opens at the frontier of novel physics that may not be available by any other means. (authors)

  9. Photoproduction of hydrogen by a non-sulphur bacterium isolated from root zones of water fern Azolla pinnata

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Srivastava, S.C.; Pandey, K.D. (Banaras Hindu Univ., Varanasi (IN). Centre of Advanced Study in Botany)

    1990-01-01

    A photosynthetic bacterium Rhodopseudomonas sp. BHU strain 1 was isolated from the root zone of water fern Azolla pinnata. The bacterium was found to produce hydrogen with potato starch under phototrophic conditions. The immobilized bacterial cells showed sustained hydrogen production with a more than 4-fold difference over free cell suspensions. The data have been discussed in the light of possible utilization of relatively cheaper raw materials by non-sulphur bacteria to evolve hydrogen. (author).

  10. Thermophilic Anaerobic Degradation of Butyrate by a Butyrate-Utilizing Bacterium in Coculture and Triculture with Methanogenic Bacteria

    OpenAIRE

    Ahring, Birgitte K.; Westermann, Peter

    1987-01-01

    We studied syntrophic butyrate degradation in thermophilic mixed cultures containing a butyrate-degrading bacterium isolated in coculture with Methanobacterium thermoautotrophicum or in triculture with M. thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic bacterium. Butyrate was β-oxidized to acetate with protons as the electron acceptors. Acetate was used concurrently with its production in the triculture. We found a higher butyrate degradation rate in th...

  11. Understanding the interaction between an obligate hyperparasitic bacterium, Pasteuria penetrans and its obligate plant-parasitic nematode host, Meloidogyne spp.

    Science.gov (United States)

    Davies, Keith G

    2009-01-01

    Pasteuria penetrans is an endospore-forming bacterium, which is a hyperparasite of root-knot nematodes Meloidogyne spp. that are economically important pests of a wide range of crops. The life cycle of the bacterium and nematode are described with emphasis on the bacterium's potential as a biocontrol agent. Two aspects that currently prohibit the commercial development of the bacterium as a biocontrol agent are the inability to culture it outside its host and its host specificity. Vegetative growth of the bacterium is possible in vitro; however, getting the vegetative stages of the bacterium to enter sporogenesis has been problematic. Insights from genomic survey sequences regarding the role of cation concentration and the phosphorylation of Spo0F have proved useful in inducing vegetative bacteria to sporulate. Similarly, genomic data have also proved useful in understanding the attachment of endospores to the cuticle of infective nematode juveniles, and a Velcro-like model of spore attachment is proposed that involves collagen-like fibres on the surface of the endospore interacting with mucins on the nematode cuticle. Ecological studies of the interactions between Daphnia and Pasteuria ramosa are examined and similarities are drawn between the co-evolution of virulence in the Daphnia system and that of plant-parasitic nematodes.

  12. Outcomes for Extremely Premature Infants

    Science.gov (United States)

    Glass, Hannah C.; Costarino, Andrew T.; Stayer, Stephen A.; Brett, Claire; Cladis, Franklyn; Davis, Peter J.

    2015-01-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for four years and is now approximately 11.5%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23–24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal EDC. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (ELBW) (CPAP, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91–95% (compared to 85–89%) avoids excess mortality. However, final analyses of data from these trials have not been published, so definitive recommendations are still pending The development of neonatal neurocognitive care visits may improve neurocognitive outcomes in this high-risk group. Long-term follow up to detect and address developmental, learning, behavioral, and social problems is critical for children born at these early gestational ages. The striking similarities in response to extreme prematurity in the lung and brain imply that agents and

  13. Gravity and Extreme Magnetism SMEX

    Science.gov (United States)

    2012-01-01

    The Gravity and Extreme Magnetism SMEX mission will be the first mission to catalogue the X-ray polarisation of many astrophysical objects including black-holes and pulsars. This first of its kind mission is enabled by the novel use of a time projection chamber as an X-ray polarimeter. The detector has been developed over the last 5 years, with the current effort charged toward a demonstration of it's technical readiness to be at level 6 prior to the preliminary design review. This talk will describe the design GEMS polarimeter and the results to date from the engineering test unit.

  14. Climate change & extreme weather vulnerability assessment framework.

    Science.gov (United States)

    2012-12-01

    The Federal Highway Administrations (FHWAs) Climate Change and Extreme Weather Vulnerability : Assessment Framework is a guide for transportation agencies interested in assessing their vulnerability : to climate change and extreme weather event...

  15. Frequently Asked Questions (FAQ) about Extreme Heat

    Science.gov (United States)

    ... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

  16. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  17. The greenhouse effect and extreme weather

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern; Kvamstoe, Nils Gunnar

    2002-01-01

    The article asserts that an anthropogenic global warming is occurring. This greenhouse effect is expected to cause more occurrences of extreme weather. It is extremely difficult, however, to relate specific weather catastrophes to global warming with certainty, since such extreme weather conditions are rare historically. The subject is controversial. The article also discusses the public debate and the risk of floods

  18. Extremity doses to interventional radiologists

    International Nuclear Information System (INIS)

    Wihtby, M.; Martin, C. J.

    2002-01-01

    Radiologists performing interventional procedures are often required to stand close to the patient's side when carrying out manipulations under fluoroscopic control. This can result in their extremities receiving a high radiation dose, due to scattered radiation. These doses are sometimes high enough to warrant that the radiologist in question be designated a classified radiation worker. Classification in the UK is a result of any worker receiving or likely to receive in the course of their duties in excess of 3/10ths of any annual dose limit (500mSv to extremities, skin). The doses to the legs of radiologists have received less attention than those to the hands, however the doses may be high, due to the proximity of the legs and feet to scattered radiation. The legs can be exposed to a relatively high level of scattered radiation as the radiation in produced from scatter of the un attenuated beam from the bottom of the patient couch. The routine monitoring of extremity doses in interventional radiology is difficult due to several factors. Firstly a wide range of interventional procedures in undertaken in every radiology department, and these procedures require many different techniques, equipment and skills. This means that the position the radiologist adopts in relation to scattering medium and therefore their exposure, depends heavily on the type of procedure. As the hands which manipulate the catheters within the patient are often located close to the patients side and to the area under irradiation, the distribution of dose across the hands can be variable, with very high localised doses, making routine monitoring difficult. The purpose of this study was to determine the magnitude and distribution of dose to the hands and legs of interventional radiologists carrying out a wide range of both diagnostic and therapeutic interventional procedures. To ascertain the most effective method of monitoring the highest dose in accordance with the Basic safety standards

  19. Shocking matter to extreme conditions

    International Nuclear Information System (INIS)

    Gupta, Y.M.; Sharma, S.M.

    1997-01-01

    A good understanding of the thermodynamic response of matter at high compression and high energy densities is important to several areas of physics. Shock-wave experiments are uniquely suited for obtaining data at extreme conditions, and a shock-compressed matter can be viewed as a condensed system with or without dissociation or as a strongly coupled plasma. This article reviews work by Da Silva et al. in which irradiances ranging from 5x10 superscript 12 to 2x10 superscript 14 W/cm 2 were used to generate 8- to 10-ns square pulses in liquid deuterium. The authors demonstrated negligible pre-heating of the sample, steady propagation of the shock wave, and direct determination of the shock wave velocity along with particle velocity and density in the shocked state. Da Silva et al. results are compared with models and other experimental information, and the usefulness of the data in other areas is assessed. 11 refs., 1 fig

  20. Weather extremes could affect agriculture

    Science.gov (United States)

    Balcerak, Ernie

    2012-05-01

    As Earth's climate warms, agricultural producers will need to adapt. Changes, especially increases in extreme events, are already having an impact on food production, according to speakers at a 1 May session on agriculture and food security at the AGU Science Policy Conference. Christopher Field, director of the Department of Global Ecology at the Carnegie Institution for Science of Washington, D. C., pointed out the complex factors that come into play in understanding food security, including spatially varying controls and stresses, incomplete models, and the potential for threshold responses. Factors that are likely to cause problems include increasing population; increasing preference for meat, which needs more land and energy inputs to produce; climate change; and increasing use of agricultural lands for biomass energy.

  1. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    Extreme sea states, which the IEC 61400-3 (2008) standard requires for the ultimate limit state (ULS) analysis of offshore wind turbines are derived to establish the design basis for the conceptual layout of deep water floating offshore wind turbine foundations in hurricane affected areas....... Especially in the initial phase of floating foundation concept development, site specific metocean data are usually not available. As the areas of interest are furthermore not covered by any design standard, in terms of design sea states, generic and in engineering terms applicable environmental background...... data is required for a type specific conceptual design. ULS conditions for different return periods are developed, which can subsequently be applied in siteindependent analysis and conceptual design. Recordings provided by National Oceanic and Atmospheric Administration (NOAA), of hurricanes along...

  2. Pneumatic tourniquets in extremity surgery.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    Pneumatic tourniquets maintain a relatively bloodless field during extremity surgery, minimize blood loss, aid identification of vital structures, and expedite the procedure. However, they may induce an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Modern pneumatic tourniquets are designed with mechanisms to regulate and maintain pressure. Routine maintenance helps ensure that these systems are working properly. The complications of tourniquet use include postoperative swelling, delay of recovery of muscle power, compression neurapraxia, wound hematoma with the potential for infection, vascular injury, tissue necrosis, and compartment syndrome. Systemic complications can also occur. The incidence of complications can be minimized by use of wider tourniquets, careful preoperative patient evaluation, and adherence to accepted principles of tourniquet use.

  3. Adhesive properties of a symbolic bacterium from a wood-boreing marine shipworm

    International Nuclear Information System (INIS)

    Imam, S.H.; Greene, R.V.; Griffin, H.L.

    1990-01-01

    Adhesive properties of cellulolytic, nitrogen-fixing bacterium isolated from a marine shipworm are described. 35 S-labeled cells of the shipworm bacterium bound preferentially Whatman no.1 cellulose filter paper, compared with its binding to other cellulose substrata or substrata lacking cellulose. The ability of the bacteria to bind to Whatman no. 1 filter paper was significantly reduced by glutaraldehyde or heat treatment of cells. Pretreatment of cells with azide, valinomycin, gramicidin-D, bis-hexafluoroacetylacetone (1799), or carbonyl cyanide-p-trifluoromethoxyphenylhydrazone inhibited adhesion activity. Cells pretreated with pronase or trypsin also exhibited reduced binding activity, but chymotrypsin and peptidase had no effect on adhesion activity. Cellodextrins and methyl cellulose 15 inhibited the adhesion of the shipworm bacteria to filter paper, whereas glucose, cellobiose, and soluble carboxymethyl cellulose had no significant effect. The divalent cation chelators EDTA and EGTA [ethylene hlycol-bis(β-aminoethyl ether)-N,N,N'N'-tetraacetic acid] had little or no effect on adhesive properties of shipworm bacteria. Also, preabsorbing the substratum with extracellular endoglucanase isolated from the ship worm bacterium or 1% bovine serum albumin had no apparent effect on bacterial binding. Low concentration (0.01%) of sodium dodecyl sulfate solubilized a fraction from whole cells, which appeared to be involved in cellular binding activity. After removal of sodium dodecyl, sulfate, several proteins in this fraction associated with intact cells. These cells exhibited up to 50% enhanced binding to filter paper in comparison to cells which had not been exposed to the sodium dodecyl sulfate-solubilized fraction

  4. ANALYSIS OF IMMUNE RESPONSES ON TRANSGENIC TIGER SHRIMP (Penaeus monodon AGAINST PATHOGENIC BACTERIUM Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Andi Parenrengi

    2014-06-01

    Full Text Available Vibriosis is one of main diseases of the black tiger shrimp Penaeus monodon infected by pathogenic bioluminous bacterium Vibrio harveyi that can cause mass mortalities in shrimp culture. The bacteria can also trigger the disease white spot syndrome virus (WSSV. An effort to produce shrimp disease-resistant strains has been done through transgenesis technology with antiviral gene transfection. By this technology, it is expected an increase in the immune response of shrimp in a variety of diseasecausing pathogens. This study aimed to determine the immune responses (total haemocytes, haemocyte differentiation, and phenoloxydase activity of transgenic tiger shrimp against pathogenic bacterium V. harveyi. Research using completely randomized design, which consists of two treatments and three replications. Test animals being used were transgenic and non-transgenic shrimp with size, weight 3.93±1.25 g and a total length of 7.59±0.87 cm. Treatments being tested were the injection of bacterium V. harveyi (density of 5x106 cfu/mL of 0.1 mL/individual on transgenic (A and non-transgenic shrimp (B. Immune response parameters such as total haemocytes, haemocyte differentiation, and phenoloxydase activity were observed on day 1, 3, and 6 days after challenging. Data were analyzed using t-test by SPSS software. The results showed that the total haemocyte of transgenic shrimp was not significantly different (P>0.05 from non-transgenic shrimp, but haemocyte differentiation and phenoloxydase activity were significantly different (P<0.05 especially on sixth days after being exposed to the bioluminescent bacteria. The study results implied that transgenic shrimp has a better immune response compared than non-transgenic shrimp.

  5. A marine bacterium, Micrococcus MCCB 104, antagonistic to vibrios in prawn larval rearing systems.

    Science.gov (United States)

    Jayaprakash, N S; Pai, S Somnath; Anas, A; Preetha, R; Philip, Rosamma; Singh, I S Bright

    2005-12-30

    A marine bacterium, Micrococcus MCCB 104, isolated from hatchery water, demonstrated extracellular antagonistic properties against Vibrio alginolyticus, V. parahaemolyticus, V. vulnificus, V. fluviallis, V. nereis, V. proteolyticus, V. mediterranei, V cholerae and Aeromonas sp., bacteria associated with Macrobrachium rosenbergii larval rearing systems. The isolate inhibited the growth of V. alginolyticus during co-culture. The antagonistic component of the extracellular product was heat-stable and insensitive to proteases, lipase, catalase and alpha-amylase. Micrococcus MCCB 104 was demonstrated to be non-pathogenic to M. rosenbergii larvae.

  6. Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery

    DEFF Research Database (Denmark)

    Martinez, Virginia; Herencias, Cristina; Jurkevitch, Edouard

    2016-01-01

    This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered......% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures....

  7. Complete genome sequence of the aerobically denitrifying thermophilic bacterium Chelatococcus daeguensis TAD1

    Directory of Open Access Journals (Sweden)

    Yunlong Yang

    Full Text Available ABSTRACT Chelatococcus daeguensis TAD1 is a themophilic bacterium isolated from a biotrickling filter used to treat NOx in Ruiming Power Plant, located in Guangzhou, China, which shows an excellent aerobic denitrification activity at high temperature. The complete genome sequence of this strain was reported in the present study. Genes related to the aerobic denitrification were identified through whole genome analysis. This work will facilitate the mechanism of aerobic denitrification and provide evidence for its potential application in the nitrogen removal.

  8. A bacterium that can grow by using arsenic instead of phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe-Simon, F; Blum, J S; Kulp, T R; Gordon, G W; Hoeft, S E; Pett-Ridge, J; Stolz, J F; Webb, S M; Weber, P K; Davies, P W; Anbar, A D; Oremland, R S

    2010-11-01

    Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus. Although these six elements make up nucleic acids, proteins and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here we describe a bacterium, strain GFAJ-1 of the Halomonadaceae, isolated from Mono Lake, CA, which substitutes arsenic for phosphorus to sustain its growth. Our data show evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids and proteins. Exchange of one of the major bio-elements may have profound evolutionary and geochemical significance.

  9. A fatal endocarditis case due to an emerging bacterium: Moraxella nonliquefaciens

    Directory of Open Access Journals (Sweden)

    C. Duployez

    2017-01-01

    Full Text Available Moraxella nonliquefaciens is a Gram-negative coccobacillus considered as a commensal organism from the upper respiratory tract, with low pathogenic potential. The phenotypical conventional identification is difficult and the matrix-assisted laser desorption/ionization time-of-flight technology has increased the resolution of identification of this bacterium. We report a fatal case of endocarditis due to M. nonliquefaciens whose identification was confirmed by 16S rRNA, and we review the literature on this pathogen in endocarditis.

  10. Dissolution of Fe(III)(hydr)oxides by an Aerobic Bacterium

    International Nuclear Information System (INIS)

    Maurice, P.

    2004-01-01

    This project investigated the effects of an aerobic Pseudomonas mendocina bacterium on the dissolution of Fe(III)(hydr)oxides. The research is important because metals and radionuclides that adsorb to Fe(III)(hydr)oxides could potentially be remobilized by dissolving bacteria. We showed that P. mendocina is capable of dissolving Fe-bearing minerals by a variety of mechanisms, including production of siderophores, pH changes, and formation of reductants. The production of siderophores by P. mendocina was quantified under a variety of growth conditions. Finally, we demonstrated that microbial siderophores may adsorb to and enhance dissolution of clay minerals

  11. Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

    OpenAIRE

    Odugbemi, T; Nwofor, C; Joiner, K T

    1988-01-01

    An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.

  12. Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

    Science.gov (United States)

    Odugbemi, T; Nwofor, C; Joiner, K T

    1988-05-01

    An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.

  13. Illuminating the landscape of host–pathogen interactions with the bacterium Listeria monocytogenes

    Science.gov (United States)

    Cossart, Pascale

    2011-01-01

    Listeria monocytogenes has, in 25 y, become a model in infection biology. Through the analysis of both its saprophytic life and infectious process, new concepts in microbiology, cell biology, and pathogenesis have been discovered. This review will update our knowledge on this intracellular pathogen and highlight the most recent breakthroughs. Promising areas of investigation such as the increasingly recognized relevance for the infectious process, of RNA-mediated regulations in the bacterium, and the role of bacterially controlled posttranslational and epigenetic modifications in the host will also be discussed. PMID:22114192

  14. A bacterium that can grow by using arsenic instead of phosphorus.

    Science.gov (United States)

    Wolfe-Simon, Felisa; Switzer Blum, Jodi; Kulp, Thomas R; Gordon, Gwyneth W; Hoeft, Shelley E; Pett-Ridge, Jennifer; Stolz, John F; Webb, Samuel M; Weber, Peter K; Davies, Paul C W; Anbar, Ariel D; Oremland, Ronald S

    2011-06-03

    Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here, we describe a bacterium, strain GFAJ-1 of the Halomonadaceae, isolated from Mono Lake, California, that is able to substitute arsenic for phosphorus to sustain its growth. Our data show evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids and proteins. Exchange of one of the major bio-elements may have profound evolutionary and geochemical importance.

  15. Aggregation of the rhizospheric bacterium Azospirillum brasilense in response to oxygen

    Science.gov (United States)

    Abdoun, Hamid; McMillan, Mary; Pereg, Lily

    2016-04-01

    Azospirillum brasilense spp. have ecological, scientific and agricultural importance. As model plant growth promoting rhizobacteria they interact with a large variety of plants, including important food and cash crops. Azospirillum strains are known for their production of plant growth hormones that enhance root systems and for their ability to fix nitrogen. Azospirillum cells transform in response to environmental cues. The production of exopolysaccharides and cell aggregation during cellular transformation are important steps in the attachment of Azospirillum to roots. We investigate signals that induce cellular transformation and aggregation in the Azospirillum and report on the importance of oxygen to the process of aggregation in this rhizospheric bacterium.

  16. Mutagenesis and reparation processes in the methylotrophic bacterium Pseudomonas methanolica after UV irradiation

    International Nuclear Information System (INIS)

    Naumov, G.N.; Bokhan, I.K.; Multykh, I.G.

    1986-01-01

    High resistance of cells of methylotrophic bacterium Pseudomonas methanolica to bactericidal and mutagenous effects of ultraviolet irradiation is shown as well as activity of reparation processes after UV irradiation. The presence of low photoreactivating activity in P. methanolica is shown as well. Observed recovery in innutritious medium and decrease of irradiated cells survival rates under effect of reparation inhibitors (coffeine and acriflavine) testify to activity of excision reparation and, perhaps, recombination branch of postreplicative reparation. No manifestation of inducible reparation system is discovered. It is concluded that increased resistance of P. methanolica cells to bactericidal and mutagenous effects of short-wave ultraviolet radiation is related to activity of exact reparation systems

  17. Extremely Low Genomic Diversity of Rickettsia japonica Distributed in Japan.

    Science.gov (United States)

    Akter, Arzuba; Ooka, Tadasuke; Gotoh, Yasuhiro; Yamamoto, Seigo; Fujita, Hiromi; Terasoma, Fumio; Kida, Kouji; Taira, Masakatsu; Nakadouzono, Fumiko; Gokuden, Mutsuyo; Hirano, Manabu; Miyashiro, Mamoru; Inari, Kouichi; Shimazu, Yukie; Tabara, Kenji; Toyoda, Atsushi; Yoshimura, Dai; Itoh, Takehiko; Kitano, Tomokazu; Sato, Mitsuhiko P; Katsura, Keisuke; Mondal, Shakhinur Islam; Ogura, Yoshitoshi; Ando, Shuji; Hayashi, Tetsuya

    2017-01-01

    Rickettsiae are obligate intracellular bacteria that have small genomes as a result of reductive evolution. Many Rickettsia species of the spotted fever group (SFG) cause tick-borne diseases known as "spotted fevers". The life cycle of SFG rickettsiae is closely associated with that of the tick, which is generally thought to act as a bacterial vector and reservoir that maintains the bacterium through transstadial and transovarial transmission. Each SFG member is thought to have adapted to a specific tick species, thus restricting the bacterial distribution to a relatively limited geographic region. These unique features of SFG rickettsiae allow investigation of how the genomes of such biologically and ecologically specialized bacteria evolve after genome reduction and the types of population structures that are generated. Here, we performed a nationwide, high-resolution phylogenetic analysis of Rickettsia japonica, an etiological agent of Japanese spotted fever that is distributed in Japan and Korea. The comparison of complete or nearly complete sequences obtained from 31 R. japonica strains isolated from various sources in Japan over the past 30 years demonstrated an extremely low level of genomic diversity. In particular, only 34 single nucleotide polymorphisms were identified among the 27 strains of the major lineage containing all clinical isolates and tick isolates from the three tick species. Our data provide novel insights into the biology and genome evolution of R. japonica, including the possibilities of recent clonal expansion and a long generation time in nature due to the long dormant phase associated with tick life cycles. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Extreme Rainfall In A City

    Science.gov (United States)

    Nkemdirim, Lawrence

    Cities contain many structures and activities that are vulnerable to severe weather. Heavy precipitation cause floods which can damage structures, compromise transportation and water supply systems, and slow down economic and social activities. Rain induced flood patterns in cities must be well understood to enable effective placement of flood control and other regulatory measures. The planning goal is not to eliminate all floods but to reduce their frequency and resulting damage. Possible approaches to such planning include probability based extreme event analysis. Precipitation is normally the most variable hydrologic element over a given area. This variability results from the distribution of clouds and in cloud processes in the atmosphere, the storm path, and the distribution of topographical features on the ground along path. Some studies suggest that point rainfall patterns are also affected by urban industrial effects hence some agreement that cities are wetter than the country surrounding them. However, there are still questions regarding the intra- urban distribution of precipitation. The sealed surfaces, urban structures, and the urban heat anomaly increase convection in cities which may enhance the generation of clouds. Increased dust and gaseous aerosols loads are effective condensation and sublimation nuclei which may also enhance the generation of precipitation. Based on these associations, the greatest amount of convection type rainfall should occur at city center. A study of summer rainfall in Calgary showed that frequencies of trace amounts of rainfall and events under 0.2mm are highest downtown than elsewhere. For amounts greater than than 0.2 mm, downtown sites were not favored. The most compelling evidence for urban-industrial precipitation enhancement came from the Metromex project around St. Loius, Missouri where maximum increases of between 5 to 30 per cent in summer rainfall downwind of the city was linked to urbanization and

  19. Chloride and organic osmolytes: a hybrid strategy to cope with elevated salinities by the moderately halophilic, chloride-dependent bacterium Halobacillus halophilus.

    Science.gov (United States)

    Saum, Stephan H; Pfeiffer, Friedhelm; Palm, Peter; Rampp, Markus; Schuster, Stephan C; Müller, Volker; Oesterhelt, Dieter

    2013-05-01

    Salt acclimation in moderately halophilic bacteria is the result of action of a grand interplay orchestrated by signals perceived from the environment. To elucidate the cellular players involved in sensing and responding to changing salinities we have determined the genome sequence of Halobacillus halophilus, a Gram-positive moderate halophilic bacterium that has a strict requirement for the anion chloride. Halobacillus halophilus synthesizes a multitude of different compatible solutes and switches its osmolyte strategy with the external salinity and growth phase. Based on the emerging genome sequence, the compatible solutes glutamate, glutamine, proline and ectoine have already been experimentally studied. The biosynthetic routes for acetyl ornithine and acetyl lysine are also delineated from the genome sequence. Halobacillus halophilus is nutritionally very versatile and most compatible solutes cannot only be produced but also used as carbon and energy sources. The genome sequence unravelled isogenes for many pathways indicating a fine regulation of metabolism. Halobacillus halophilus is unique in integrating the concept of compatible solutes with the second fundamental principle to cope with salt stress, the accumulation of molar concentrations of salt (Cl(-)) in the cytoplasm. Extremely halophilic bacteria/archaea, which exclusively rely on the salt-in strategy, have a high percentage of acidic proteins compared with non-halophiles with a low percentage. Halobacillus halophilus has an intermediate position which is consistent with its ability to integrate both principles. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  20. Ultra-broadband 2D electronic spectroscopy of carotenoid-bacteriochlorophyll interactions in the LH1 complex of a purple bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Maiuri, Margherita [CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, P.zza L. da Vinci 32, Milano 20133 (Italy); Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544 (United States); Réhault, Julien; Polli, Dario; Cerullo, Giulio, E-mail: giulio.cerullo@polimi.it [CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, P.zza L. da Vinci 32, Milano 20133 (Italy); Carey, Anne-Marie; Hacking, Kirsty; Cogdell, Richard J. [Glasgow Biomedical Research Centre, IBLS, University of Glasgow, 126 Place, Glasgow G12 8TA, Scotland (United Kingdom); Garavelli, Marco [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, Université de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France); Lüer, Larry [Madrid Institute for Advanced Studies, IMDEA Nanociencia, Madrid (Spain)

    2015-06-07

    We investigate the excitation energy transfer (EET) pathways in the photosynthetic light harvesting 1 (LH1) complex of purple bacterium Rhodospirillum rubrum with ultra-broadband two-dimensional electronic spectroscopy (2DES). We employ a 2DES apparatus in the partially collinear geometry, using a passive birefringent interferometer to generate the phase-locked pump pulse pair. This scheme easily lends itself to two-color operation, by coupling a sub-10 fs visible pulse with a sub-15-fs near-infrared pulse. This unique pulse combination allows us to simultaneously track with extremely high temporal resolution both the dynamics of the photoexcited carotenoid spirilloxanthin (Spx) in the visible range and the EET between the Spx and the B890 bacterio-chlorophyll (BChl), whose Q{sub x} and Q{sub y} transitions peak at 585 and 881 nm, respectively, in the near-infrared. Global analysis of the one-color and two-color 2DES maps unravels different relaxation mechanisms in the LH1 complex: (i) the initial events of the internal conversion process within the Spx, (ii) the parallel EET from the first bright state S{sub 2} of the Spx towards the Q{sub x} state of the B890, and (iii) the internal conversion from Q{sub x} to Q{sub y} within the B890.

  1. Biochemical and structural insights into xylan utilization by the thermophilic bacterium Caldanaerobius polysaccharolyticus.

    Science.gov (United States)

    Han, Yejun; Agarwal, Vinayak; Dodd, Dylan; Kim, Jason; Bae, Brian; Mackie, Roderick I; Nair, Satish K; Cann, Isaac K O

    2012-10-12

    Hemicellulose is the next most abundant plant cell wall component after cellulose. The abundance of hemicellulose such as xylan suggests that their hydrolysis and conversion to biofuels can improve the economics of bioenergy production. In an effort to understand xylan hydrolysis at high temperatures, we sequenced the genome of the thermophilic bacterium Caldanaerobius polysaccharolyticus. Analysis of the partial genome sequence revealed a gene cluster that contained both hydrolytic enzymes and also enzymes key to the pentose-phosphate pathway. The hydrolytic enzymes in the gene cluster were demonstrated to convert products from a large endoxylanase (Xyn10A) predicted to anchor to the surface of the bacterium. We further use structural and calorimetric studies to demonstrate that the end products of Xyn10A hydrolysis of xylan are recognized and bound by XBP1, a putative solute-binding protein, likely for transport into the cell. The XBP1 protein showed preference for xylo-oligosaccharides as follows: xylotriose > xylobiose > xylotetraose. To elucidate the structural basis for the oligosaccharide preference, we solved the co-crystal structure of XBP1 complexed with xylotriose to a 1.8-Å resolution. Analysis of the biochemical data in the context of the co-crystal structure reveals the molecular underpinnings of oligosaccharide length specificity.

  2. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike; Mehboob, Farrakh; van Gelder, Antonie H; Rijpstra, W Irene C; Damsté , Jaap S Sinninghe; Stams, Alfons J M

    2010-01-01

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  3. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike

    2010-08-03

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  4. Influence of yeast and lactic acid bacterium on the constituent profile of soy sauce during fermentation.

    Science.gov (United States)

    Harada, Risa; Yuzuki, Masanobu; Ito, Kotaro; Shiga, Kazuki; Bamba, Takeshi; Fukusaki, Eiichiro

    2017-02-01

    Soy sauce is a Japanese traditional seasoning composed of various constituents that are produced by various microbes during a long-term fermentation process. Due to the complexity of the process, the investigation of the constituent profile during fermentation is difficult. Metabolomics, the comprehensive study of low molecular weight compounds in biological samples, is thought to be a promising strategy for deep understanding of the constituent contribution to food flavor characteristics. Therefore, metabolomics is suitable for the analysis of soy sauce fermentation. Unfortunately, only few and unrefined studies of soy sauce fermentation using metabolomics approach have been reported. Therefore, we investigated changes in low molecular weight hydrophilic and volatile compounds of soy sauce using gas chromatography/mass spectrometry (GC/MS)-based non-targeted metabolic profiling. The data were analyzed by statistical analysis to evaluate influences of yeast and lactic acid bacterium on the constituent profile. Consequently, our results suggested a novel finding that lactic acid bacterium affected the production of several constituents such as cyclotene, furfural, furfuryl alcohol and methional in the soy sauce fermentation process. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. A highly infective plant-associated bacterium influences reproductive rates in pea aphids.

    Science.gov (United States)

    Hendry, Tory A; Clark, Kelley J; Baltrus, David A

    2016-02-01

    Pea aphids, Acyrthosiphon pisum, have the potential to increase reproduction as a defence against pathogens, though how frequently this occurs or how infection with live pathogens influences this response is not well understood. Here we determine the minimum infective dose of an environmentally common bacterium and possible aphid pathogen, Pseudomonas syringae, to determine the likelihood of pathogenic effects to pea aphids. Additionally, we used P. syringae infection to investigate how live pathogens may alter reproductive rates. We found that oral bacterial exposure decreased subsequent survival of aphids in a dose-dependent manner and we estimate that ingestion of less than 10 bacterial cells is sufficient to increase aphid mortality. Pathogen dose was positively related to aphid reproduction. Aphids exposed to low bacterial doses showed decreased, although statistically indistinguishable, fecundity compared to controls. Aphids exposed to high doses reproduced significantly more than low dose treatments and also more, but not significantly so, than controls. These results are consistent with previous studies suggesting that pea aphids may use fecundity compensation as a response to pathogens. Consequently, even low levels of exposure to a common plant-associated bacterium may therefore have significant effects on pea aphid survival and reproduction.

  6. Reduction of nitric oxide catalyzed by hydroxylamine oxidoreductase from an anammox bacterium.

    Science.gov (United States)

    Irisa, Tatsuya; Hira, Daisuke; Furukawa, Kenji; Fujii, Takao

    2014-12-01

    The hydroxylamine oxidoreductase (HAO) from the anammox bacterium, Candidatus Kuenenia stuttgartiensis has been reported to catalyze the oxidation of hydroxylamine (NH2OH) to nitric oxide (NO) by using bovine cytochrome c as an oxidant. In contrast, we investigated whether the HAO from anammox bacterium strain KSU-1 could catalyze the reduction of NO with reduced benzyl viologen (BVred) and the NO-releasing reagent, NOC 7. The reduction proceeded, resulting in the formation of NH2OH as a product. The oxidation rate of BVred was proportional to the concentration of BVred itself for a short period in each experiment, a situation that was termed quasi-steady state. The analyses of the states at various concentrations of HAO allowed us to determine the rate constant for the catalytic reaction, (2.85 ± 0.19) × 10(5) M(-1) s(-1), governing NO reduction by BVred and HAO, which was comparable to that reported for the HAO from the ammonium oxidizer, Nitrosomonas with reduced methyl viologen. These results suggest that the anammox HAO functions to adjust anammox by inter-conversion of NO and NH2OH depending on the redox potential of the physiological electron transfer protein in anammox bacteria. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Removal of arsenic from groundwater by using a native isolated arsenite-oxidizing bacterium.

    Science.gov (United States)

    Kao, An-Chieh; Chu, Yu-Ju; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

    2013-12-01

    Arsenic (As) contamination of groundwater is a significant public health concern. In this study, the removal of arsenic from groundwater using biological processes was investigated. The efficiency of arsenite (As(III)) bacterial oxidation and subsequent arsenate (As(V)) removal from contaminated groundwater using bacterial biomass was examined. A novel As(III)-oxidizing bacterium (As7325) was isolated from the aquifer in the blackfoot disease (BFD) endemic area in Taiwan. As7325 oxidized 2300μg/l As(III) using in situ As(III)-contaminated groundwater under aerobic conditions within 1d. After the oxidation of As(III) to As(V), As(V) removal was further examined using As7325 cell pellets. The results showed that As(V) could be adsorbed efficiently by lyophilized As7325 cell pellets, the efficiency of which was related to lyophilized cell pellet concentration. Our study conducted the examination of an alternative technology for the removal of As(III) and As(V) from groundwater, indicating that the oxidation of As(III)-contaminated groundwater by native isolated bacterium, followed by As(V) removal using bacterial biomass is a potentially effective technology for the treatment of As(III)-contaminated groundwater. © 2013.

  8. The fate of a nitrobenzene-degrading bacterium in pharmaceutical wastewater treatment sludge.

    Science.gov (United States)

    Ren, Yuan; Yang, Juan; Chen, Shaoyi

    2015-12-01

    This paper describes the fate of a nitrobenzene-degrading bacterium, Klebsiella oxytoca NBA-1, which was isolated from a pharmaceutical wastewater treatment facility. The 90-day survivability of strain NBA-1 after exposure to sludge under anaerobic and aerobic conditions was investigated. The bacterium was inoculated into sludge amended with glucose and p-chloronitrobenzene (p-CNB) to compare the bacterial community variations between the modified sludge and nitrobenzene amendment. The results showed that glucose had no obvious effect on nitrobenzene biodegradation in the co-metabolism process, regardless of the presence/absence of oxygen. When p-CNB was added under anaerobic conditions, the biodegradation rate of nitrobenzene remained unchanged although p-CNB inhibited the production of aniline. The diversity of the microbial community increased and NBA-1 continued to be one of the dominant strains. Under aerobic conditions, the degradation rate of both nitrobenzene and p-CNB was only 20% of that under anaerobic conditions. p-CNB had a toxic effect on the microorganisms in the sludge so that most of the DGGE (denaturing gradient gel electrophoresis) bands, including that of NBA-1, began to disappear under aerobic conditions after 90days of exposure. These data show that the bacterial community was stable under anaerobic conditions and the microorganisms, including NBA-1, were more resistant to the adverse environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Expression and surface display of Cellulomonas endoglucanase in the ethanologenic bacterium Zymobacter palmae

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Motoki; Akahoshi, Tomohiro; Okamoto, Kenji; Yanase, Hideshi [Tottori Univ. (Japan). Dept. of Chemistry and Biotechnology

    2012-11-15

    In order to reduce the cost of bioethanol production from lignocellulosic biomass, we developed a tool for cell surface display of cellulolytic enzymes on the ethanologenic bacterium Zymobacter palmae. Z. palmae is a novel ethanol-fermenting bacterium capable of utilizing a broad range of sugar substrates, but not cellulose. Therefore, to express and display heterologous cellulolytic enzymes on the Z. palmae cell surface, we utilized the cell-surface display motif of the Pseudomonas ice nucleation protein Ina. The gene encoding Ina from Pseudomonas syringae IFO3310 was cloned, and its product was comprised of three functional domains: an N-terminal domain, a central domain with repeated amino acid residues, and a C-terminal domain. The N-terminal domain of Ina was shown to function as the anchoring motif for a green fluorescence protein fusion protein in Escherichia coli. To express a heterologous cellulolytic enzyme extracellularly in Z. palmae, we fused the N-terminal coding sequence of Ina to the coding sequence of an N-terminal-truncated Cellulomonas endoglucanase. Z. palmae cells carrying the fusion endoglucanase gene were shown to degrade carboxymethyl cellulose. Although a portion of the expressed fusion endoglucanase was released from Z. palmae cells into the culture broth, we confirmed the display of the protein on the cell surface by immunofluorescence microscopy. The results indicate that the N-terminal anchoring motif of Ina from P. syringae enabled the translocation and display of the heterologous cellulase on the cell surface of Z. palmae. (orig.)

  10. Nematode-bacterium symbioses--cooperation and conflict revealed in the "omics" age.

    Science.gov (United States)

    Murfin, Kristen E; Dillman, Adler R; Foster, Jeremy M; Bulgheresi, Silvia; Slatko, Barton E; Sternberg, Paul W; Goodrich-Blair, Heidi

    2012-08-01

    Nematodes are ubiquitous organisms that have a significant global impact on ecosystems, economies, agriculture, and human health. The applied importance of nematodes and the experimental tractability of many species have promoted their use as models in various research areas, including developmental biology, evolutionary biology, ecology, and animal-bacterium interactions. Nematodes are particularly well suited for the investigation of host associations with bacteria because all nematodes have interacted with bacteria during their evolutionary history and engage in a variety of association types. Interactions between nematodes and bacteria can be positive (mutualistic) or negative (pathogenic/parasitic) and may be transient or stably maintained (symbiotic). Furthermore, since many mechanistic aspects of nematode-bacterium interactions are conserved, their study can provide broader insights into other types of associations, including those relevant to human diseases. Recently, genome-scale studies have been applied to diverse nematode-bacterial interactions and have helped reveal mechanisms of communication and exchange between the associated partners. In addition to providing specific information about the system under investigation, these studies also have helped inform our understanding of genome evolution, mutualism, and innate immunity. In this review we discuss the importance and diversity of nematodes, "omics"' studies in nematode-bacterial systems, and the wider implications of the findings.

  11. A highly infective plant-associated bacterium influences reproductive rates in pea aphids

    Science.gov (United States)

    Hendry, Tory A.; Clark, Kelley J.; Baltrus, David A.

    2016-01-01

    Pea aphids, Acyrthosiphon pisum, have the potential to increase reproduction as a defence against pathogens, though how frequently this occurs or how infection with live pathogens influences this response is not well understood. Here we determine the minimum infective dose of an environmentally common bacterium and possible aphid pathogen, Pseudomonas syringae, to determine the likelihood of pathogenic effects to pea aphids. Additionally, we used P. syringae infection to investigate how live pathogens may alter reproductive rates. We found that oral bacterial exposure decreased subsequent survival of aphids in a dose-dependent manner and we estimate that ingestion of less than 10 bacterial cells is sufficient to increase aphid mortality. Pathogen dose was positively related to aphid reproduction. Aphids exposed to low bacterial doses showed decreased, although statistically indistinguishable, fecundity compared to controls. Aphids exposed to high doses reproduced significantly more than low dose treatments and also more, but not significantly so, than controls. These results are consistent with previous studies suggesting that pea aphids may use fecundity compensation as a response to pathogens. Consequently, even low levels of exposure to a common plant-associated bacterium may therefore have significant effects on pea aphid survival and reproduction. PMID:26998321

  12. Application of agglomerative clustering for analyzing phylogenetically on bacterium of saliva

    Science.gov (United States)

    Bustamam, A.; Fitria, I.; Umam, K.

    2017-07-01

    Analyzing population of Streptococcus bacteria is important since these species can cause dental caries, periodontal, halitosis (bad breath) and more problems. This paper will discuss the phylogenetically relation between the bacterium Streptococcus in saliva using a phylogenetic tree of agglomerative clustering methods. Starting with the bacterium Streptococcus DNA sequence obtained from the GenBank, then performed characteristic extraction of DNA sequences. The characteristic extraction result is matrix form, then performed normalization using min-max normalization and calculate genetic distance using Manhattan distance. Agglomerative clustering technique consisting of single linkage, complete linkage and average linkage. In this agglomerative algorithm number of group is started with the number of individual species. The most similar species is grouped until the similarity decreases and then formed a single group. Results of grouping is a phylogenetic tree and branches that join an established level of distance, that the smaller the distance the more the similarity of the larger species implementation is using R, an open source program.

  13. Isolation, cloning and characterization of an azoreductase from the halophilic bacterium Halomonas elongata.

    Science.gov (United States)

    Eslami, Maryam; Amoozegar, Mohammad Ali; Asad, Sedigheh

    2016-04-01

    Azo dyes are a major class of colorants used in various industries including textile, paper and food. These dyes are regarded as pollutant since they are not readily reduced under aerobic conditions. Halomonas elongata, a halophilic bacterium, has the ability to decolorize different mono and di-azo dyes in anoxic conditions. In this study the putative azoreductase gene of H. elongata, formerly annotated as acp, was isolated, heterologously expressed in Escherichia coli, purified and characterized. The gene product, AzoH, was found to have a molecular mass of 22 kDa. The enzyme requires NADH, as an electron donor for its activity. The apparent Km was 63 μM for NADH and 12 μM for methyl red as a mono-azo dye substrate. The specific activity for methyl red was 0.27 μmol min(-1)mg(-1). The optimum enzyme activity was achieved in 50mM sodium phosphate buffer at pH 6. Although increased salinity resulted in reduced activity, AzoH could decolorize azo dye at NaCl concentrations up to 15% (w/v). The enzyme was also shown to be able to decolorize remazol black B as a representative of di-azo dyes. This is the first report describing the sequence and activity of an azo-reducing enzyme from a halophilic bacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Quorum sensing activity of Citrobacter amalonaticus L8A, a bacterium isolated from dental plaque.

    Science.gov (United States)

    Goh, Share-Yuan; Khan, Saad Ahmed; Tee, Kok Keng; Abu Kasim, Noor Hayaty; Yin, Wai-Fong; Chan, Kok-Gan

    2016-02-10

    Cell-cell communication is also known as quorum sensing (QS) that happens in the bacterial cells with the aim to regulate their genes expression in response to increased cell density. In this study, a bacterium (L8A) isolated from dental plaque biofilm was identified as Citrobacter amalonaticus by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Its N-acylhomoserine-lactone (AHL) production was screened by using two types of AHL biosensors namely Chromobacterium violaceum CV026 and Escherichia coli [pSB401]. Citrobacter amalonaticus strain L8A was identified and confirmed producing numerous types of AHL namely N-butyryl-L-homoserine lactone (C4-HSL), N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL) and N-hexadecanoyl-L-homoserine lactone (C16-HSL). We performed the whole genome sequence analysis of this oral isolate where its genome sequence reveals the presence of QS signal synthase gene and our work will pave the ways to study the function of the related QS genes in this bacterium.

  15. Enhanced Cadmium (Cd Phytoextraction from Contaminated Soil using Cd-Resistant Bacterium

    Directory of Open Access Journals (Sweden)

    Kunchaya Setkit

    2014-01-01

    Full Text Available A cadmium (Cd-resistant bacterium, Micrococcus sp. MU1, is able to produce indole-3-acetic acid and promotes root elongation and plant growth. The potential of this bacterium on enhancement of Cd uptake and bioaccumulation of Cd in Helianthus annuus L. planted in Cd-contaminated soil was evaluated in greenhouse condition. The results showed that Micrococcus sp. MU1promoted the growth of H. annuus L. by increasing the root length, stem height, dry biomass, root to shoot ratio and also significantly increased Cd accumulation in the root and above-ground tissues of H. annuus L. compared to uninoculated control. Re-inoculation with Micrococcus sp. MU1in contaminated soil helped in promoting plant growth and Cd phytoextraction throughout the cultivation period. In addition, phytoextraction coefficient and translocation factor (TF of H. annuus L. inoculated with Micrococcus sp. MU1were higher than that of uninoculated control and TF continuously increased with time. Our results suggested that Micrococcus sp. MU1 has an ability to enhance plant growth and Cd uptake in H. annuus L. Synergistic interaction between Micrococcus sp. MU1 and H. annuus L. could be further applied for Cd phytoextraction in polluted areas.

  16. Biofilm and capsule formation of the diatom Achnanthidium minutissimum are affected by a bacterium.

    Science.gov (United States)

    Windler, Miriam; Leinweber, Katrin; Bartulos, Carolina Rio; Philipp, Bodo; Kroth, Peter G

    2015-04-01

    Photoautotrophic biofilms play an important role in various aquatic habitats and are composed of prokaryotic and/or eukaryotic organisms embedded in extracellular polymeric substances (EPS). We have isolated diatoms as well as bacteria from freshwater biofilms to study organismal interactions between representative isolates. We found that bacteria have a strong impact on the biofilm formation of the pennate diatom Achnanthidium minutissimum. This alga produces extracellular capsules of insoluble EPS, mostly carbohydrates (CHO), only in the presence of bacteria (xenic culture). The EPS themselves also have a strong impact on the aggregation and attachment of the algae. In the absence of bacteria (axenic culture), A. minutissimum did not form capsules and the cells grew completely suspended. Fractionation and quantification of CHO revealed that the diatom in axenic culture produces large amounts of soluble CHO, whereas in the xenic culture mainly insoluble CHO were detected. For investigation of biofilm formation by A. minutissimum, a bioassay was established using a diatom satellite Bacteroidetes bacterium that had been shown to induce capsule formation of A. minutissimum. Interestingly, capsule and biofilm induction can be achieved by addition of bacterial spent medium, indicating that soluble hydrophobic molecules produced by the bacterium may mediate the diatom/bacteria interaction. With the designed bioassay, a reliable tool is now available to study the chemical interactions between diatoms and bacteria with consequences for biofilm formation. © 2015 Phycological Society of America.

  17. Characterization of carbon dioxide concentrating chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel.

    Science.gov (United States)

    Kumar, Manish; Morya, Raj; Gnansounou, Edgard; Larroche, Christian; Thakur, Indu Shekhar

    2017-11-01

    Proteomics and metabolomics analysis has become a powerful tool for characterization of microbial ability for fixation of Carbon dioxide. Bacterial community of palaeoproterozoic metasediments was enriched in the shake flask culture in the presence of NaHCO 3 . One of the isolate showed resistance to NaHCO 3 (100mM) and was identified as Serratia sp. ISTD04 by 16S rRNA sequence analysis. Carbon dioxide fixing ability of the bacterium was established by carbonic anhydrase enzyme assay along with proteomic analysis by LC-MS/MS. In proteomic analysis 96 proteins were identified out of these 6 protein involved in carbon dioxide fixation, 11 in fatty acid metabolism, indicating the carbon dioxide fixing potency of bacterium along with production of biofuel. GC-MS analysis revealed that hydrocarbons and FAMEs produced by bacteria within the range of C 13 -C 24 and C 11 -C 19 respectively. Presence of 59% saturated and 41% unsaturated organic compounds, make it a better fuel composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Optimization of liquid media and biosafety assessment for algae-lysing bacterium NP23.

    Science.gov (United States)

    Liao, Chunli; Liu, Xiaobo; Shan, Linna

    2014-09-01

    To control algal bloom caused by nutrient pollution, a wild-type algae-lysing bacterium was isolated from the Baiguishan reservoir in Henan province of China and identified as Enterobacter sp. strain NP23. Algal culture medium was optimized by applying a Placket-Burman design to obtain a high cell concentration of NP23. Three minerals (i.e., 0.6% KNO3, 0.001% MnSO4·H2O, and 0.3% K2HPO4) were found to be independent factors critical for obtaining the highest cell concentration of 10(13) CFU/mL, which was 10(4) times that of the control. In the algae-lysing experiment, the strain exhibited a high lysis rate for the 4 algae test species, namely, Chlorella vulgari, Scenedesmus, Microcystis wesenbergii, and Chlorella pyrenoidosa. Acute toxicity and mutagenicity tests showed that the bacterium NP23 had no toxic and mutagenic effects on fish, even in large doses such as 10(7) or 10(9) CFU/mL. Thus, Enterobacter sp. strain NP23 has strong potential application in the microbial algae-lysing project.

  19. Adopt a Bacterium - an active and collaborative learning experience in microbiology based on social media.

    Science.gov (United States)

    Piantola, Marco Aurélio Floriano; Moreno, Ana Carolina Ramos; Matielo, Heloísa Alonso; Taschner, Natalia Pasternak; Cavalcante, Rafael Ciro Marques; Khan, Samia; Ferreira, Rita de Cássia Café

    2018-04-24

    The "Adopt a Bacterium" project is based on the use of social network as a tool in Microbiology undergraduate education, improving student learning and encouraging students to participate in collaborative learning. The approach involves active participation of both students and teachers, emphasizing knowledge exchange, based on widely used social media. Students were organized in groups and asked to adopt a specific bacterial genus and, subsequently, submit posts about "adopted genus". The formative assessment is based on posting information on Facebook®, and the summative assessment involves presentation of seminars about the adopted theme. To evaluate the project, students filled out three anonymous and voluntary surveys. Most of the students enjoyed the activities and positively evaluated the experience. A large amount of students declared a change in their attitude towards the way they processed information, especially regarding the use of scientific sources. Finally, we evaluated knowledge retention six months after the end of the course and students were able to recall relevant Microbiology concepts. Our results suggest that the "Adopt a Bacterium" project represents a useful strategy in Microbiology learning and may be applied to other academic fields. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass.

    Science.gov (United States)

    Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves; Alberti, Adriana; Weissenbach, Jean; Salanoubat, Marcel; Tolonen, Andrew C

    2014-11-01

    Microbial metabolism of plant polysaccharides is an important part of environmental carbon cycling, human nutrition, and industrial processes based on cellulosic bioconversion. Here we demonstrate a broadly applicable method to analyze how microbes catabolize plant polysaccharides that integrates carbohydrate-active enzyme (CAZyme) assays, RNA sequencing (RNA-seq), and anaerobic growth screening. We apply this method to study how the bacterium Clostridium phytofermentans ferments plant biomass components including glucans, mannans, xylans, galactans, pectins, and arabinans. These polysaccharides are fermented with variable efficiencies, and diauxies prioritize metabolism of preferred substrates. Strand-specific RNA-seq reveals how this bacterium responds to polysaccharides by up-regulating specific groups of CAZymes, transporters, and enzymes to metabolize the constituent sugars. Fifty-six up-regulated CAZymes were purified, and their activities show most polysaccharides are degraded by multiple enzymes, often from the same family, but with divergent rates, specificities, and cellular localizations. CAZymes were then tested in combination to identify synergies between enzymes acting on the same substrate with different catalytic mechanisms. We discuss how these results advance our understanding of how microbes degrade and metabolize plant biomass.

  1. Production and characterization of bioemulsifier from a marine bacterium, Acinetobacter calcoaceticus subsp. anitratus SM7

    Directory of Open Access Journals (Sweden)

    Kulnaree Phetrong

    2008-05-01

    Full Text Available Marine bacterium strain SM7 was isolated as a bioemulsifier-producing bacterium from oil-spilled seawater in Songkhla lagoon, Thailand. It was identified as Acinetobacter calcoaceticus subsp. anitratus based on morphology, biochemicalcharacteristics and 16S rRNA sequence. A. calcoaceticus subsp. anitratus SM7 produced an extracellular emulsifying agent when grown in a minimal salt medium (pH 7.0 containing 0.3% (v/v n-heptadecane and 0.1% (w/v ammoniumhydrogen carbonate as carbon source and nitrogen source, respectively, at 30oC with agitation rate of 200 rpm. Crude bioemulsifier was recovered from the culture supernatant by ethanol precipitation with a yield of 2.94 g/l and had a criticalemulsifier concentration of 0.04 g/ml. The crude bioemulsifier was capable of emulsifying n-hexadecane in a broad pH range (6-12, temperatures (30-121oC and in the presence of NaCl up to 12% (w/v. The bioemulsifier was stable in saltsolution ranging from 0 to 0.1% (w/v of MgCl2 and CaCl2. The broad range of pH stability, thermostability and salt tolerance suggested that the bioemulsifier from A. calcoaceticus subsp. anitratus SM7 could be useful in environmentalapplication, especially bioremediation of oil-polluted seawater.

  2. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

    Directory of Open Access Journals (Sweden)

    Aulie Banerjee

    Full Text Available Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13C NMR, we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  3. [Identification and function test of an alkali-tolerant denitrifying bacterium].

    Science.gov (United States)

    Wang, Ru; Zheng, Ping; Li, Wei; Chen, Hui; Chen, Tingting; Ghulam, Abbas

    2013-04-04

    We obtained an alkali-tolerant denitrifying bacterium, and determined its denitrifying activity and alkali-tolerance. An alkali-tolerant denitrifying bacterial strain was obtained by isolation and purification. We identified the bacterial strain by morphological observation, physiological test and 16S rRNA analysis. We determined the denitrifying activity and alkali-tolerance by effects of initial nitrate concentration and initial pH on denitrification. An alkali-tolerant denitrifier strain R9 was isolated from the lab-scale high-rate denitrifying reactor, and it was identified as Diaphorobater nitroreducens. The strain R9 grew heterotrophically with methanol as the electron donor and nitrate as the electron acceptor. The nitrate conversion was 93.25% when strain R9 was cultivated for 288 h with initial nitrate concentration 50 mg/L and initial pH 9.0. The denitrification activity could be inhibited at high nitrate concentration with a half inhibition constant of 202.73 mg N/L. Strain R9 showed a good alkali tolerance with the nitrate removal rate at pH 11.0 remained 86% of that at pH 9.0. Strain R9 was identified as Diaphorobater nitroreducens, and it was an alkali-tolerant denitrifying bacterium with optimum pH value of 9.0.

  4. Extreme heat and runoff extremes in the Swiss Alps

    Directory of Open Access Journals (Sweden)

    M. Zappa

    2007-06-01

    Full Text Available The hydrological response of Swiss river basins to the 2003 European summer heatwave was evaluated by a combined analysis of historical discharge records and specific applications of distributed hydrological modeling. In the summer of 2003, the discharge from headwater streams of the Swiss Central Plateau was only 40%–60% of the long-term average. For alpine basins runoff was about 60%–80% of the average. Glacierized basins showed the opposite behavior. According to the degree of glacierization, the average summer runoff was close or even above average. The hydrological model PREVAH was applied for the period 1982–2005. Even if the model was not calibrated for such extreme meteorological conditions, it was well able to simulate the hydrological responses of three basins. The aridity index φ describes feedbacks between hydrological and meteorological anomalies, and was adopted as an indicator of hydrological drought. The anomalies of φ and temperature in the summer of 2003 exceeded the 1982–2005 mean by more than 2 standard deviations. Catchments without glaciers showed negative correlations between φ and discharge R. In basins with about 15% glacierization, φ and R were not correlated. River basins with higher glacier percentages showed a positive correlation between φ and R. Icemelt was positively correlated with φ and reduced the variability of discharge with larger amounts of meltwater. Runoff generation from the non-glaciated sub-areas was limited by high evapotranspiration and reduced precipitation. The 2003 summer heatwave could be a precursor to similar events in the near future. Hydrological models and further data analysis will allow the identification of the most sensitive regions where heatwaves may become a recurrent natural hazard with large environmental, social and economical impacts.

  5. BELM: Bayesian extreme learning machine.

    Science.gov (United States)

    Soria-Olivas, Emilio; Gómez-Sanchis, Juan; Martín, José D; Vila-Francés, Joan; Martínez, Marcelino; Magdalena, José R; Serrano, Antonio J

    2011-03-01

    The theory of extreme learning machine (ELM) has become very popular on the last few years. ELM is a new approach for learning the parameters of the hidden layers of a multilayer neural network (as the multilayer perceptron or the radial basis function neural network). Its main advantage is the lower computational cost, which is especially relevant when dealing with many patterns defined in a high-dimensional space. This brief proposes a bayesian approach to ELM, which presents some advantages over other approaches: it allows the introduction of a priori knowledge; obtains the confidence intervals (CIs) without the need of applying methods that are computationally intensive, e.g., bootstrap; and presents high generalization capabilities. Bayesian ELM is benchmarked against classical ELM in several artificial and real datasets that are widely used for the evaluation of machine learning algorithms. Achieved results show that the proposed approach produces a competitive accuracy with some additional advantages, namely, automatic production of CIs, reduction of probability of model overfitting, and use of a priori knowledge.

  6. Driving Extreme Efficiency to Market

    Science.gov (United States)

    Garbesi, Karina

    2014-03-01

    The rapid development of extremely energy efficient appliances and equipment is essential to curtail catastrophic climate disruption. This will require the on-going development of products that apply all best-practices and that take advantage of the synergies of hybridization and building integration. Beyond that, it requires the development of new disruptive technologies and concepts. To facilitate these goals, in 2011 the Lawrence Berkeley National Laboratory and the U.S. Department of Energy launched the Max Tech and Beyond Design Competition for Ultra-Low-Energy-Use Appliances and Equipment. Now in its third year, the competition supports faculty-lead student design teams at U.S. universities to develop and test new technology prototypes. This talk describes what the competition and the Max Tech Program are doing to drive such rapid technology progress and to facilitate the entry to the market of successful Max Tech prototypes. The talk also initiates a discussion of physicists' unique role in driving that technology progress faster and farther. Emerging Technologies, Building Technologies Office, U.S. Department of Energy.

  7. Masks for extreme ultraviolet lithography

    International Nuclear Information System (INIS)

    Cardinale, G; Goldsmith, J; Kearney, P A; Larson, C; Moore, C E; Prisbrey, S; Tong, W; Vernon, S P; Weber, F; Yan, P-Y.

    1998-01-01

    In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed

  8. Gene adaptation to extreme environments

    International Nuclear Information System (INIS)

    Marlaire, P.; Rodriguez, V.; Kerner, N.

    2005-01-01

    Full text: This work is oriented to the study of gene adaptation to extreme conditions, such as the hydrothermal system located in Copahue, Neuquen, Argentina. The organisms living there develop under two pressure selection conditions: the high temperature of thermal water and the strong impact of ultraviolet (UV) radiation. Several microorganisms found in this region were isolated and different colonies resistant to UV radiation were selected, a Geobacillus thermoleovorans strain identified through 16S RNA sequence, being the most remarkable. A gene library was prepared out of this strain with UV sensitive bacteria BH200 (uvrA::Tn10). A number of clones were isolated by means of UV selection, the most outstanding being a gene carrier able to codify for the guanosine monophosphate synthetase enzyme (GMPs). The suitability of said enzyme was proved by means of additional assays performed on ght 1 bacteria (guaA26::Tn 10) which lacked the enzyme. A transcript of 1100 pb was detected through Northern Blot. The result was consistent with that obtained for the mapping of the starting transcription site. The cloned GMPs produces an increase in growth speed and a greater biomass in BH200 bacteria. (author)

  9. Infection in the ischemic lower extremity.

    Science.gov (United States)

    Fry, D E; Marek, J M; Langsfeld, M

    1998-06-01

    Infections in the lower extremity of the patient with ischemia can cover a broad spectrum of different diseases. An understanding of the particular pathophysiologic circumstances in the ischemic extremity can be of great value in understanding the natural history of the disease and the potential complications that may occur. Optimizing blood flow to the extremity by using revascularization techniques is important for any patient with an ischemic lower extremity complicated by infection or ulceration. Infections in the ischemic lower extremity require local débridement and systemic antibiotics. For severe infections, such as necrotizing fasciitis or the fetid foot, more extensive local débridement and even amputation may be required. Fundamentals of managing prosthetic graft infection require removing the infected prosthesis, local wound débridement, and systemic antibiotics while attempting to preserve viability of the lower extremity using autogenous graft reconstruction.

  10. Antibacterial Property of a Coral-Associated Bacterium Pseudoalteromonas luteoviolacea Against Shrimp Pathogenic Vibrio harveyi (In Vitro Study

    Directory of Open Access Journals (Sweden)

    OCKY KARNA RADJASA

    2005-06-01

    Full Text Available A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA. The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved signature regions for peptide synthetases and revealed a high similarity to NosD (40% identity, a multifunctional peptide synthetase from Nostoc sp. GSV224, and NdaB (44% identity, a peptide synthetase module of Nodularia spumigena

  11. Antibacterial Property of a Coral-Associated Bacterium Pseudoalteromonas luteoviolacea Against Shrimp Pathogenic Vibrio harveyi (In Vitro Study

    Directory of Open Access Journals (Sweden)

    OCKY KARNA RADJASA

    2005-06-01

    Full Text Available A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA.The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved signature regions for peptide synthetases and revealed a high similarity to NosD (40% identity, a multifunctional peptide synthetase from Nostoc sp. GSV224, and NdaB (44% identity, a peptide synthetase module of Nodularia spumigena.

  12. On the Extreme Wave Height Analysis

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The determination of the design wave height is usually based on the statistical analysis of long-term extreme wave height measurements. After an introduction to the procedure of the extreme wave height analysis, the paper presents new development concerning various aspects of the extreme wave...... height analysis. Finally, the paper gives a practical example based on a data set of the hindcasted wave heights for a deep water location in the Mediterranean Sea....

  13. Extreme Events in Nature and Society

    CERN Document Server

    Albeverio, Sergio; Kantz, Holger

    2006-01-01

    Significant, and usually unwelcome, surprises, such as floods, financial crisis, epileptic seizures, or material rupture, are the topics of Extreme Events in Nature and Society. The book, authored by foremost experts in these fields, reveals unifying and distinguishing features of extreme events, including problems of understanding and modelling their origin, spatial and temporal extension, and potential impact. The chapters converge towards the difficult problem of anticipation: forecasting the event and proposing measures to moderate or prevent it. Extreme Events in Nature and Society will interest not only specialists, but also the general reader eager to learn how the multifaceted field of extreme events can be viewed as a coherent whole.

  14. Controlling extreme events on complex networks

    Science.gov (United States)

    Chen, Yu-Zhong; Huang, Zi-Gang; Lai, Ying-Cheng

    2014-08-01

    Extreme events, a type of collective behavior in complex networked dynamical systems, often can have catastrophic consequences. To develop effective strategies to control extreme events is of fundamental importance and practical interest. Utilizing transportation dynamics on complex networks as a prototypical setting, we find that making the network ``mobile'' can effectively suppress extreme events. A striking, resonance-like phenomenon is uncovered, where an optimal degree of mobility exists for which the probability of extreme events is minimized. We derive an analytic theory to understand the mechanism of control at a detailed and quantitative level, and validate the theory numerically. Implications of our finding to current areas such as cybersecurity are discussed.

  15. Bacterium-like Particles for efficient immune stimulation of existing vaccines and new subunit vaccines in mucosal applications

    Directory of Open Access Journals (Sweden)

    Natalija eVan Braeckel-Budimir

    2013-09-01

    Full Text Available The successful development of a mucosal vaccine critically depends on the use of a safe and effective immunostimulant and/or carrier system. This review describes the effectiveness and mode of action of an immunostimulating particle derived from bacteria in mucosal subunit vaccines. The non-living particles, designated Bacterium-like Particles (BLPs are based on the food-grade bacterium Lactococcus lactis. The focus of the overview is on the development of intranasal BLP-based vaccines to prevent diseases caused by influenza and respiratory syncytial virus, and includes a selection of Phase I clinical data for the intranasal FluGEM vaccine.

  16. The impact of a pathogenic bacterium on a social carnivore population.

    Science.gov (United States)

    Höner, Oliver P; Wachter, Bettina; Goller, Katja V; Hofer, Heribert; Runyoro, Victor; Thierer, Dagmar; Fyumagwa, Robert D; Müller, Thomas; East, Marion L

    2012-01-01

    1. The long-term ecological impact of pathogens on group-living, large mammal populations is largely unknown. We evaluated the impact of a pathogenic bacterium, Streptococcus equi ruminatorum, and other key ecological factors on the dynamics of the spotted hyena Crocuta crocuta population in the Ngorongoro Crater, Tanzania. 2. We compared key demographic parameters during two years when external signs of bacterial infection were prevalent ('outbreak') and periods of five years before and after the outbreak when such signs were absent or rare. We also tested for density dependence and calculated the basic reproductive rate R(0) of the bacterium. 3. During the five pre-outbreak years, the mean annual hyena mortality rate was 0.088, and annual population growth was relatively high (13.6%). During the outbreak, mortality increased by 78% to a rate of 0.156, resulting in an annual population decline of 4.3%. After the outbreak, population size increased moderately (5.1%) during the first three post-outbreak years before resuming a growth similar to pre-outbreak levels (13.9%). We found no evidence that these demographic changes were driven by density dependence or other ecological factors. 4. Most hyenas showed signs of infection when prey abundance in their territory was low. During the outbreak, mortality increased among adult males and yearlings, but not among adult females - the socially dominant group members. These results suggest that infection and mortality were modulated by factors linked to low social status and poor nutrition. During the outbreak, we estimated R(0) for the bacterium to be 2.7, indicating relatively fast transmission. 5. Our results suggest that the short-term 'top-down' impact of S. equi ruminatorum during the outbreak was driven by 'bottom-up' effects on nutritionally disadvantaged age-sex classes, whereas the longer-term post-outbreak reduction in population growth was caused by poor survival of juveniles during the outbreak and subsequent

  17. Thermodynamics of extremal rotating thin shells in an extremal BTZ spacetime and the extremal black hole entropy

    Science.gov (United States)

    Lemos, José P. S.; Minamitsuji, Masato; Zaslavskii, Oleg B.

    2017-02-01

    In a (2 +1 )-dimensional spacetime with a negative cosmological constant, the thermodynamics and the entropy of an extremal rotating thin shell, i.e., an extremal rotating ring, are investigated. The outer and inner regions with respect to the shell are taken to be the Bañados-Teitelbom-Zanelli (BTZ) spacetime and the vacuum ground state anti-de Sitter spacetime, respectively. By applying the first law of thermodynamics to the extremal thin shell, one shows that the entropy of the shell is an arbitrary well-behaved function of the gravitational area A+ alone, S =S (A+). When the thin shell approaches its own gravitational radius r+ and turns into an extremal rotating BTZ black hole, it is found that the entropy of the spacetime remains such a function of A+, both when the local temperature of the shell at the gravitational radius is zero and nonzero. It is thus vindicated by this analysis that extremal black holes, here extremal BTZ black holes, have different properties from the corresponding nonextremal black holes, which have a definite entropy, the Bekenstein-Hawking entropy S (A+)=A/+4G , where G is the gravitational constant. It is argued that for extremal black holes, in particular for extremal BTZ black holes, one should set 0 ≤S (A+)≤A/+4G;i.e., the extremal black hole entropy has values in between zero and the maximum Bekenstein-Hawking entropy A/+4 G . Thus, rather than having just two entropies for extremal black holes, as previous results have debated, namely, 0 and A/+4 G , it is shown here that extremal black holes, in particular extremal BTZ black holes, may have a continuous range of entropies, limited by precisely those two entropies. Surely, the entropy that a particular extremal black hole picks must depend on past processes, notably on how it was formed. A remarkable relation between the third law of thermodynamics and the impossibility for a massive body to reach the velocity of light is also found. In addition, in the procedure, it

  18. Area spectra of near extremal black holes

    International Nuclear Information System (INIS)

    Chen, Deyou; Yang, Haitang; Zu, Xiaotao

    2010-01-01

    Motivated by Maggiore's new interpretation of quasinormal modes, we investigate area spectra of a near extremal Schwarzschild-de Sitter black hole and a higher-dimensional near extremal Reissner-Nordstrom-de Sitter black hole. The result shows that the area spectra are equally spaced and irrelevant to the parameters of the black holes. (orig.)

  19. Meaning and Forms of Political Extremism

    Directory of Open Access Journals (Sweden)

    Uwe Backes

    2007-12-01

    Full Text Available The article seeks to contribute to the conceptualisation of political extremism and to lay a foundation for further theoretical studies which are explanatory in nature. A sketch of the history of the concepts follows a discussion of structural characteristics and then a typological examination of forms of extremism, particularly those of the 20th and 21st century.

  20. Extremely strict ideals in Banach spaces

    Indian Academy of Sciences (India)

    Abstract. Motivated by the notion of an ideal introduced by Godefroy et al. (Stu- dia Math. 104 (1993) 13–59), in this article, we introduce and study the notion of an extremely strict ideal. For a Poulsen simplex K, we show that the space of affine contin- uous functions on K is an extremely strict ideal in the space of continuous ...

  1. SIZE AND SHAPE FACTOR EXTREMES OF SPHEROIDS

    Directory of Open Access Journals (Sweden)

    Daniel Hlubinka

    2011-05-01

    Full Text Available In the paper we consider random prolate (oblate spheroids and their random profiles. The limiting distribution of the extremal characteristics of the spheroids is related to the limiting distribution of the corresponding extremal characteristics of the profiles. The difference between the analysis of the prolate and oblate spheroids is discussed. We propose the possible application of the theoretical results.

  2. Complex Plasma Research Under Extreme Conditions

    International Nuclear Information System (INIS)

    Ishihara, Osamu

    2008-01-01

    Complex plasma research under extreme conditions is described. The extreme conditions include low-dimensionality for self-organized structures of dust particles, dust magnetization in high magnetic field, criticality in phase transition, and cryogenic environment for Coulomb crystals and dust dynamics.

  3. A Fourier analysis of extremal events

    DEFF Research Database (Denmark)

    Zhao, Yuwei

    is the extremal periodogram. The extremal periodogram shares numerous asymptotic properties with the periodogram of a linear process in classical time series analysis: the asymptotic distribution of the periodogram ordinates at the Fourier frequencies have a similar form and smoothed versions of the periodogram...

  4. Roentgenological findings in muscular alterations of extremities

    International Nuclear Information System (INIS)

    Palvoelgyi, R.

    1978-01-01

    A survey of roentgenological findings in muscular alterations of extremities based on the author's experiences and on the literature is presented. Following a description of the normal roentgen anatomy, the alterations in different diseases of interstitial lipomatosis are demonstrated. By roentgenological examinations differt muscular lesions of the extremities can be differentiated and the clinical follow-up verified. (orig.) [de

  5. Extremal vectors and rectifiability | Enflo | Quaestiones Mathematicae

    African Journals Online (AJOL)

    Extremal vectors and rectifiability. ... The concept of extremal vectors of a linear operator with a dense range but not onto on a Hilbert space was introduced by P. Enflo in 1996 as a new approach to study invariant subspaces ... We show that in general curves that map numbers to backward minimal vectors are not rectifiable.

  6. A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

    Science.gov (United States)

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

    2013-06-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  7. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    Science.gov (United States)

    Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

  8. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    OpenAIRE

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  9. Heavy fermions and extreme conditions

    International Nuclear Information System (INIS)

    Cheikine, Ilia

    2000-01-01

    Three heavy electron systems, CeCu 2 Si 2 , CePd 2 Si 2 and UGe 2 , were investigated by transport, quantum oscillations (CePd 2 Si 2 ) and neutron diffraction (UGe 2 ) measurements. The experiments were performed under extreme conditions of very low temperature, high magnetic field and hydrostatic pressure. In the case of CeCu 2 Si 2 , we followed the evolution of the magnetic A-phase that is found to collapse rapidly under pressure. We found evidence for a relation between the A-phase and the presence of a maximum in the temperature dependence of H c2 . Our analysis showed that at low pressure, the sign of the exchange integral should be negative, thus superconductivity is enhanced by an increase in the paramagnetic susceptibility as in the Jaccarino-Peter effect. The anisotropy of the initial slope of H c2 and therefore that of the effective mass was found to change under pressure. For CePd 2 Si 2 , both the de Haas-van Alphen effect at ambient pressure and the electrical resistivity under pressure were studied. The latter reveals a non-Fermi liquid behavior in the vicinity of the antiferromagnetic quantum critical point, P c ∼ kbar. The analysis of H c2 at P c shows that the superconducting state is well described by a weak coupling, clean limit model with a slightly anisotropic orbital limit and a strongly anisotropic paramagnetic one. UGe 2 is shown to demonstrate the coexistence of ferromagnetism and superconductivity that develops just below the ferromagnetic quantum critical point, P c ∼16 kbar. The measurements of the resistivity under pressure point to a possible existence of another phase boundary and thus another quantum critical point, P x ∼ 12 kbar, within the ferromagnetic state. The P-T phase diagram containing both P c and P x was sketched, and a possible relation between P x and the development of superconductivity was discussed. The temperature dependence of H c2 demonstrates a variety of novel behaviors, which cannot be understood within

  10. The personal dispositions of violent extremism

    Directory of Open Access Journals (Sweden)

    Davydov D.G.

    2017-04-01

    Full Text Available The paper presents the differences in the nature of extremism and radicalism, and the necessity of introducing the concept of "violent extremism." It is shown that the ideology is the explanation of extremist behavior, rather than its cause. The ideology of extremism often eclectic, contradictory and can easily be transformed by changing the object of hostility, depending on the situation. For the description of the psychological causes of extremism it is proposed to use the concept of personal disposition. Disposition is the preferred way to subjective interpretation of reality and reflects both the specific needs of a person as well the typical social situations where it realized and personal experience. Considered the following dispositions of violent extremism: the Cult of force and aggression, Intolerance, Out-group hostility Conventional coercion, Social pessimism and destructiveness, Mystical, Fighting and overcoming, Nihilism to law, Anti-subjectivism. It is proposed to use these dispositions as diagnostic criteria and for preventing and correcting.

  11. [Crossing borders. The motivation of extreme sportsmen].

    Science.gov (United States)

    Opaschowski, H W

    2005-08-01

    In his article "Crossing borders -- the motivation of extreme sportsmen" the author gets systematically to the bottom of the question of why extreme sportsmen voluntarily take risks and endanger themselves. Within the scope of a representative sampling 217 extreme sportsmen -- from the fields of mountain biking, trekking and free climbing, canoyning, river rafting and deep sea diving, paragliding, parachuting, bungee jumping and survival training -- give information about their personal motives. What fascinates them? The attraction of risk? The search for sensation? Or the drop out of everyday life? And what comes afterwards? Does in the end the whole life become an extreme sport? Fact is: they live extremely, because they want to move beyond well-trodden paths. To escape the boredom of everyday life they are searching for the kick, the thrill, the no-limit experience. It's about calculated risk between altitude flight and deep sea adventure.

  12. Sensitivity of European wheat to extreme weather

    DEFF Research Database (Denmark)

    Mäkinen, H; Kaseva, J; Trnka, M

    2018-01-01

    The frequency and intensity of extreme weather is increasing concomitant with changes in the global climate change. Although wheat is the most important food crop in Europe, there is currently no comprehensive empirical information available regarding the sensitivity of European wheat to extreme...... weather. In this study, we assessed the sensitivity of European wheat yields to extreme weather related to phenology (sowing, heading) in cultivar trials across Europe (latitudes 37.21° to 61.34° and longitudes −6.02° to 26.24°) during the period 1991–2014. All the observed agro-climatic extremes (≥31 °C...... wheat cultivars that responded positively (+10%) to drought after sowing, or frost during winter (−15 °C and −20 °C). Positive responses to extremes were often shown by cultivars associated with specific regions, such as good performance under high temperatures by southern-origin cultivars. Consequently...

  13. Mortality impact of extreme winter temperatures

    Science.gov (United States)

    Díaz, Julio; García, Ricardo; López, César; Linares, Cristina; Tobías, Aurelio; Prieto, Luis

    2005-01-01

    During the last few years great attention has been paid to the evaluation of the impact of extreme temperatures on human health. This paper examines the effect of extreme winter temperature on mortality in Madrid for people older than 65, using ARIMA and GAM models. Data correspond to 1,815 winter days over the period 1986 1997, during which time a total of 133,000 deaths occurred. The daily maximum temperature (Tmax) was shown to be the best thermal indicator of the impact of climate on mortality. When total mortality was considered, the maximum impact occured 7 8 days after a temperature extreme; for circulatory diseases the lag was between 7 and 14 days. When respiratory causes were considered, two mortality peaks were evident at 4 5 and 11 days. When the impact of winter extreme temperatures was compared with that associated with summer extremes, it was found to occur over a longer term, and appeared to be more indirect.

  14. Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL

    Institute of Scientific and Technical Information of China (English)

    TAYLOR Shauna M; HE Yiliang; ZHAO Bin; HUANG Jue

    2009-01-01

    Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4+-N). In order to further analyze its removal ability, several experiments were conducted to identify the growth and ammonium removal response in different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30℃, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth. The nitrification products hydroxylamine (NH2OH), nitrite (NO2-) and nitrate (NO3-) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions.

  15. Structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC118.

    Science.gov (United States)

    Lobley, Carina M C; Aller, Pierre; Douangamath, Alice; Reddivari, Yamini; Bumann, Mario; Bird, Louise E; Nettleship, Joanne E; Brandao-Neto, Jose; Owens, Raymond J; O'Toole, Paul W; Walsh, Martin A

    2012-12-01

    The structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC188 has been determined at 1.72 Å resolution. The structure was solved by molecular replacement, which identified the functional homodimer in the asymmetric unit. Despite only showing 57% sequence identity to its closest homologue, the structure adopted the typical α and β D-ribose 5-phosphate isomerase fold. Comparison to other related structures revealed high homology in the active site, allowing a model of the substrate-bound protein to be proposed. The determination of the structure was expedited by the use of in situ crystallization-plate screening on beamline I04-1 at Diamond Light Source to identify well diffracting protein crystals prior to routine cryocrystallography.

  16. Bioethanol production from mannitol by a newly isolated bacterium, Enterobacter sp. JMP3.

    Science.gov (United States)

    Wang, Jing; Kim, Young Mi; Rhee, Hong Soon; Lee, Min Woo; Park, Jong Moon

    2013-05-01

    In this study a new bacterium capable of growing on brown seaweed Laminaria japonica, Enterobacter sp. JMP3 was isolated from the gut of turban shell, Batillus cornutus. In anaerobic condition, it produced high yields of ethanol (1.15 mol-EtOH mol-mannitol(-1)) as well as organic acids from mannitol, the major carbohydrate component of L. japonica. Based on carbon distribution and metabolic flux analysis, it was revealed that mannitol was more favorable than glucose for ethanol production due to their different redox states. This indicates that L. japonica is one of the promising feedstock for bioethanol production. Additionally, the mannitol dehydrogenation pathway in Enterobacter sp. JMP3 was examined and verified. Finally, an attempt was made to explore the possibility of controlling ethanol production by altering the redox potential via addition of external NADH in mannitol fermentation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.

    2015-01-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research.

  18. Polymicrobial infection and bacterium-mediated epigenetic modification of DNA tumor viruses contribute to pathogenesis.

    Science.gov (United States)

    Doolittle, J M; Webster-Cyriaque, J

    2014-04-29

    ABSTRACT The human body plays host to a wide variety of microbes, commensal and pathogenic. In addition to interacting with their host, different microbes, such as bacteria and viruses, interact with each other, sometimes in ways that exacerbate disease. In particular, gene expression of a number of viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV), is known to be regulated by epigenetic modifications induced by bacteria. These viruses establish latent infection in their host cells and can be reactivated by bacterial products. Viral reactivation has been suggested to contribute to periodontal disease and AIDS. In addition, bacterium-virus interactions may play a role in cancers, such as Kaposi's sarcoma, gastric cancer, and head and neck cancer. It is important to consider the effects of coexisting bacterial infections when studying viral diseases in vivo.

  19. Molecular Mechanisms of Adaptation of the Moderately Halophilic Bacterium Halobacillis halophilus to Its Environment

    Directory of Open Access Journals (Sweden)

    Inga Hänelt

    2013-02-01

    Full Text Available The capability of osmoadaptation is a prerequisite of organisms that live in an environment with changing salinities. Halobacillus halophilus is a moderately halophilic bacterium that grows between 0.4 and 3 M NaCl by accumulating both chloride and compatible solutes as osmolytes. Chloride is absolutely essential for growth and, moreover, was shown to modulate gene expression and activity of enzymes involved in osmoadaptation. The synthesis of different compatible solutes is strictly salinity- and growth phase-dependent. This unique hybrid strategy of H. halophilus will be reviewed here taking into account the recently published genome sequence. Based on identified genes we will speculate about possible scenarios of the synthesis of compatible solutes and the uptake of potassium ion which would complete our knowledge of the fine-tuned osmoregulation and intracellular osmolyte balance in H. halophilus.

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

    Directory of Open Access Journals (Sweden)

    Xiaoliang Wang

    2009-07-01

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

  1. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

    Science.gov (United States)

    Eads, David A; Biggins, Dean E

    2015-08-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

  2. Microbially influenced corrosion of stainless steel by marine bacterium Vibrio natriegens: (I) Corrosion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Sha; Tian Jintao [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Chen Shougang, E-mail: sgchen@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Lei Yanhua; Chang Xueting; Liu Tao [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yin Yansheng, E-mail: yys2006@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2009-04-30

    The microbially influenced corrosion of stainless steel (SS) by marine bacterium Vibrio natriegens (V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA)) and electrochemical techniques (the open circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves ). AFM images corroborated the results from the EIS models which show biofilm attachment and subsequent detachment over time. The SEM images revealed the occurrence of micro-pitting corrosion underneath the biofilms on the metal surface after the biofilm removal. The presence of carbon, oxygen, phosphor and sulfur obtained from EDXA proved the formation of biofilm. The electrochemical results showed that the corrosion of SS was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance (R{sub ct}) obtained from EIS and the increase in corrosion current densities obtained from potentiodynamic polarization curves.

  3. Structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC118

    International Nuclear Information System (INIS)

    Lobley, Carina M. C.; Aller, Pierre; Douangamath, Alice; Reddivari, Yamini; Bumann, Mario; Bird, Louise E.; Nettleship, Joanne E.; Brandao-Neto, Jose; Owens, Raymond J.; O’Toole, Paul W.; Walsh, Martin A.

    2012-01-01

    The crystal structure of ribose 5-phosphate isomerase has been determined to 1.72 Å resolution and is presented with a brief comparison to other known ribose 5-phosphate isomerase A structures. The structure of ribose 5-phosphate isomerase from the probiotic bacterium Lactobacillus salivarius UCC188 has been determined at 1.72 Å resolution. The structure was solved by molecular replacement, which identified the functional homodimer in the asymmetric unit. Despite only showing 57% sequence identity to its closest homologue, the structure adopted the typical α and β d-ribose 5-phosphate isomerase fold. Comparison to other related structures revealed high homology in the active site, allowing a model of the substrate-bound protein to be proposed. The determination of the structure was expedited by the use of in situ crystallization-plate screening on beamline I04-1 at Diamond Light Source to identify well diffracting protein crystals prior to routine cryocrystallography

  4. UV-induced variability of the amylolytic thermophilic bacterium Bacillus diastaticus

    International Nuclear Information System (INIS)

    Murygina, V.P.

    1978-01-01

    UV-induced variability of a thermophilic bacterium Bacillus diastaticus 13 by amylase formation has been studied. It has been shown, that variability limits in amylase biosynthesis vary from 2.2 to 158.7% under UV irradiation. At 41.8x10 2 erg/mm 2 UV dose a ''plus-variant'' designated as the UV1 mutant has been prepared. Its subsequent selection without using mutagene permitted to select the UV 1-25 variant, exceeding the initial strain in amylase biosynthesis by 43.3%. Under UV irradiation two low-active in biosynthesis amylases of the mutant were prepared. Demands for growth factors of some mutant have been studied as well

  5. UV-induced variability of the amylolytic thermophilic bacterium Bacillus diastaticus

    Energy Technology Data Exchange (ETDEWEB)

    Murygina, V P

    1978-03-01

    Ultroviolet-radioinduced variability in analyase biosynthesis of a thermophilic bacterium Bacillus diastaticus 13, has been studied. It has been shown that amylase biosynthesis varies from 2.2 to 158.7% under UV irradiation. At 41.8x10/sup 2/ erg/mm/sup 2/ UV dose, a ''plus-variant'' designated as the UV1 mutant has been prepared. Its subsequent selection without using mutagene permitted to select the UV 1-25 variant, exceeding the initial strain in amylase biosynthesis by 43.3%. Under UV irradiation, two mutants with reduced amylose biosynthesis activity were prepared. Demands for growth factors by some mutants have been studied as well.

  6. Pathogenic bacteriumVibrio harveyi: an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans

    Institute of Scientific and Technical Information of China (English)

    QIAO Ying; WANG Jun; MAO Yong; LIU Min; CHEN Ruanni; SU Yongquan; KE Qiaozhen; HAN Kunhuang; ZHENG Weiqiang

    2017-01-01

    Vibrio harveyi, known as a pathogenic bacterium caused severe secondary bacterial infections of the large yellow croaker Larimichthys crocea, was identified as an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans. Meta 16S sequencing method was used to identify the bacterial flora in C. irritans, and V. harveyi was isolated via culture-dependent method.Vibrio harveyi was observed in cytoplasm of C. irritans at the stage of tomont both by transmission electron microscopy and by Fluorescencein situ hybridization; no signal, however, was detected in nucleus area. The relationship betweenV. harveyi and C. irritans and the role of endosymbioticV. harveyi inC. irritans merit further investigation.

  7. Analysis of convergent gene transcripts in the obligate intracellular bacterium Rickettsia prowazekii.

    Directory of Open Access Journals (Sweden)

    Andrew Woodard

    2011-01-01

    Full Text Available Termination of transcription is an important component of bacterial gene expression. However, little is known concerning this process in the obligate intracellular pathogen and model for reductive evolution, Rickettsia prowazekii. To assess transcriptional termination in this bacterium, transcripts of convergent gene pairs, some containing predicted intrinsic terminators, were analyzed. These analyses revealed that, rather than terminating at a specific site within the intervening region between the convergent genes, most of the transcripts demonstrated either a lack of termination within this region, which generated antisense RNA, or a putative non-site-specific termination that occurred throughout the intervening sequence. Transcripts terminating at predicted intrinsic terminators, as well as at a putative Rho-dependant terminator, were also examined and found to vary based on the rickettsial host environment. These results suggest that transcriptional termination, or lack thereof, plays a role in rickettsial gene regulation.

  8. A unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium

    Science.gov (United States)

    Hoshi, Ayaka; Oshima, Kenro; Kakizawa, Shigeyuki; Ishii, Yoshiko; Ozeki, Johji; Hashimoto, Masayoshi; Komatsu, Ken; Kagiwada, Satoshi; Yamaji, Yasuyuki; Namba, Shigetou

    2009-01-01

    One of the most important themes in agricultural science is the identification of virulence factors involved in plant disease. Here, we show that a single virulence factor, tengu-su inducer (TENGU), induces witches' broom and dwarfism and is a small secreted protein of the plant-pathogenic bacterium, phytoplasma. When tengu was expressed in Nicotiana benthamiana plants, these plants showed symptoms of witches' broom and dwarfism, which are typical of phytoplasma infection. Transgenic Arabidopsis thaliana lines expressing tengu exhibited similar symptoms, confirming the effects of tengu expression on plants. Although the localization of phytoplasma was restricted to the phloem, TENGU protein was detected in apical buds by immunohistochemical analysis, suggesting that TENGU was transported from the phloem to other cells. Microarray analyses showed that auxin-responsive genes were significantly down-regulated in the tengu-transgenic plants compared with GUS-transgenic control plants. These results suggest that TENGU inhibits auxin-related pathways, thereby affecting plant development. PMID:19329488

  9. Novel Poly[(R-3-Hydroxybutyrate]-Producing Bacterium Isolated from a Bolivian Hypersaline Lake

    Directory of Open Access Journals (Sweden)

    María Soledad Marqués-Calvo

    2013-01-01

    Full Text Available Poly[(R-3-hydroxybutyrate] (PHB constitutes a biopolymer synthesized from renewable resources by various microorganisms. This work focuses on finding a new PHB-producing bacterium capable of growing in conventional media used for industrial biopolymer production, its taxonomical identification, and characterization of its biopolymer. Thus, a bacterial isolation process was carried out from environmental samples of water and mud. Among the isolates, strain S29 was selected and used in a fed-batch fermentation to generate a biopolymer. This biopolymer was recovered and identified as PHB homopolymer. Surprisingly, it featured several fractions of different molecular masses, and thermal properties unusual for PHB. Hence, the microorganism S29, genetically identified as a new strain of Bacillus megaterium, proved to be interesting not only due to its growth and PHB accumulation kinetics under the investigated cultivation conditions, but also due to the thermal properties of the produced PHB.

  10. Concentration and transport of nitrate by the mat-forming sulphur bacterium Thioploca

    Science.gov (United States)

    Fossing, H.; Gallardo, V. A.; Jørgensen, B. B.; Hüttel, M.; Nielsen, L. P.; Schulz, H.; Canfield, D. E.; Forster, S.; Glud, R. N.; Gundersen, J. K.; Küver, J.; Ramsing, N. B.; Teske, A.; Thamdrup, B.; Ulloa, O.

    1995-04-01

    MARINE species of Thioploca occur over 3,000 km along the continental shelf off Southern Peru and North and Central Chile1-4. These filamentous bacteria live in bundles surrounded by a common sheath and form thick mats on the sea floor under the oxygen-minimum zone in the upwelling region, at between 40 and 280 m water depth. The metabolism of this marine bacterium5,6 remained a mystery until long after its discovery1,7. We report here that Thioploca cells are able to concentrate nitrate to up to 500 mM in a liquid vacuole that occupies >80% of the cell volume. Gliding filaments transport this nitrate 5-10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment.

  11. Proteomic Profiling of the Dioxin-Degrading Bacterium Sphingomonas wittichii RW1

    Directory of Open Access Journals (Sweden)

    David R. Colquhoun

    2012-01-01

    Full Text Available Sphingomonas wittichii RW1 is a bacterium of interest due to its ability to degrade polychlorinated dioxins, which represent priority pollutants in the USA and worldwide. Although its genome has been fully sequenced, many questions exist regarding changes in protein expression of S. wittichii RW1 in response to dioxin metabolism. We used difference gel electrophoresis (DIGE and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS to identify proteomic changes induced by growth on dibenzofuran, a surrogate for dioxin, as compared to acetate. Approximately 10% of the entire putative proteome of RW1 could be observed. Several components of the dioxin and dibenzofuran degradation pathway were shown to be upregulated, thereby highlighting the utility of using proteomic analyses for studying bioremediation agents. This is the first global protein analysis of a microorganism capable of utilizing the carbon backbone of both polychlorinated dioxins and dibenzofurans as the sole source for carbon and energy.

  12. Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Maresca, Julia A; Yunker, Colleen E

    2004-01-01

    The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C....... tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), zeta-carotene desaturase (crtQ/CT1414), gamma......-carotene desaturase (crtU/CT0323), carotenoid 1',2'-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants...

  13. Isolation and characterization of a new hydrogen-utilizing bacterium from the rumen.

    Science.gov (United States)

    Rieu-Lesme, F; Fonty, G; Doré, J

    1995-01-01

    A new H2/CO2-utilizing acetogenic bacterium was isolated from the rumen of a mature deer. This is the first report of a spore-forming Gram-negative bacterial species from the rumen. The organism was a strictly anaerobic, motile rod and was able to grow autotrophically on hydrogen and carbon dioxide. Acetate was the major product detected. Glucose, fructose and lactate were also fermented heterotrophically. The optimum pH for growth was 7.0-7.5, and the optimum temperature was 37-42 degrees C. Yeast extract was required for growth and rumen fluid was highly stimulatory. The DNA base ratio was 52.9 +/- 0.5 mol% G+C. On the basis of these characteristics and fermentation products, the isolate was considered to be different from acetogenic bacteria described previously.

  14. BOG: R-package for Bacterium and virus analysis of Orthologous Groups

    Directory of Open Access Journals (Sweden)

    Jincheol Park

    2015-01-01

    Full Text Available BOG (Bacterium and virus analysis of Orthologous Groups is a package for identifying groups of differentially regulated genes in the light of gene functions for various virus and bacteria genomes. It is designed to identify Clusters of Orthologous Groups (COGs that are enriched among genes that have gone through significant changes under different conditions. This would contribute to the detection of pathogens, an important scientific research area of relevance in uncovering bioterrorism, among others. Particular statistical analyses include hypergeometric, Mann–Whitney rank sum, and gene set enrichment. Results from the analyses are organized and presented in tabular and graphical forms for ease of understanding and dissemination of results. BOG is implemented as an R-package, which is available from CRAN or can be downloaded from http://www.stat.osu.edu/~statgen/SOFTWARE/BOG/.

  15. Extreme Weather and Climate: Workshop Report

    Science.gov (United States)

    Sobel, Adam; Camargo, Suzana; Debucquoy, Wim; Deodatis, George; Gerrard, Michael; Hall, Timothy; Hallman, Robert; Keenan, Jesse; Lall, Upmanu; Levy, Marc; hide

    2016-01-01

    Extreme events are the aspects of climate to which human society is most sensitive. Due to both their severity and their rarity, extreme events can challenge the capacity of physical, social, economic and political infrastructures, turning natural events into human disasters. Yet, because they are low frequency events, the science of extreme events is very challenging. Among the challenges is the difficulty of connecting extreme events to longer-term, large-scale variability and trends in the climate system, including anthropogenic climate change. How can we best quantify the risks posed by extreme weather events, both in the current climate and in the warmer and different climates to come? How can we better predict them? What can we do to reduce the harm done by such events? In response to these questions, the Initiative on Extreme Weather and Climate has been created at Columbia University in New York City (extreme weather.columbia.edu). This Initiative is a University-wide activity focused on understanding the risks to human life, property, infrastructure, communities, institutions, ecosystems, and landscapes from extreme weather events, both in the present and future climates, and on developing solutions to mitigate those risks. In May 2015,the Initiative held its first science workshop, entitled Extreme Weather and Climate: Hazards, Impacts, Actions. The purpose of the workshop was to define the scope of the Initiative and tremendously broad intellectual footprint of the topic indicated by the titles of the presentations (see Table 1). The intent of the workshop was to stimulate thought across disciplinary lines by juxtaposing talks whose subjects differed dramatically. Each session concluded with question and answer panel sessions. Approximately, 150 people were in attendance throughout the day. Below is a brief synopsis of each presentation. The synopses collectively reflect the variety and richness of the emerging extreme event research agenda.

  16. Survival Strategies of the Plant-Associated Bacterium Enterobacter sp. Strain EG16 under Cadmium Stress.

    Science.gov (United States)

    Chen, Yanmei; Chao, Yuanqing; Li, Yaying; Lin, Qingqi; Bai, Jun; Tang, Lu; Wang, Shizhong; Ying, Rongrong; Qiu, Rongliang

    2016-01-04

    Plant-associated bacteria are of great interest because of their potential use in phytoremediation. However, their ability to survive and promote plant growth in metal-polluted soils remains unclear. In this study, a soilborne Cd-resistant bacterium was isolated and identified as Enterobacter sp. strain EG16. It tolerates high external Cd concentrations (Cd(2+) MIC, >250 mg liter(-1)) and is able to produce siderophores and the plant hormone indole-3-acetic acid (IAA), both of which contribute to plant growth promotion. Surface biosorption in this strain accounted for 31% of the total Cd accumulated. The potential presence of cadmium sulfide, shown by energy-dispersive X-ray (EDX) analysis, suggested intracellular Cd binding as a Cd response mechanism of the isolate. Cd exposure resulted in global regulation at the transcriptomic level, with the bacterium switching to an energy-conserving mode by inhibiting energy-consuming processes while increasing the production of stress-related proteins. The stress response system included increased import of sulfur and iron, which become deficient under Cd stress, and the redirection of sulfur metabolism to the maintenance of intracellular glutathione levels in response to Cd toxicity. Increased production of siderophores, responding to Cd-induced Fe deficiency, not only is involved in the Cd stress response systems of EG16 but may also play an important role in promoting plant growth as well as alleviating the Cd-induced inhibition of IAA production. The newly isolated strain EG16 may be a suitable candidate for microbially assisted phytoremediation due to its high resistance to Cd and its Cd-induced siderophore production, which is likely to contribute to plant growth promotion. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Genome Sequence of the Plant Growth Promoting Endophytic Bacterium Enterobacter sp. 638

    Science.gov (United States)

    Taghavi, Safiyh; van der Lelie, Daniel; Hoffman, Adam; Zhang, Yian-Biao; Walla, Michael D.; Vangronsveld, Jaco; Newman, Lee; Monchy, Sébastien

    2010-01-01

    Enterobacter sp. 638 is an endophytic plant growth promoting gamma-proteobacterium that was isolated from the stem of poplar (Populus trichocarpa×deltoides cv. H11-11), a potentially important biofuel feed stock plant. The Enterobacter sp. 638 genome sequence reveals the presence of a 4,518,712 bp chromosome and a 157,749 bp plasmid (pENT638-1). Genome annotation and comparative genomics allowed the identification of an extended set of genes specific to the plant niche adaptation of this bacterium. This includes genes that code for putative proteins involved in survival in the rhizosphere (to cope with oxidative stress or uptake of nutrients released by plant roots), root adhesion (pili, adhesion, hemagglutinin, cellulose biosynthesis), colonization/establishment inside the plant (chemiotaxis, flagella, cellobiose phosphorylase), plant protection against fungal and bacterial infections (siderophore production and synthesis of the antimicrobial compounds 4-hydroxybenzoate and 2-phenylethanol), and improved poplar growth and development through the production of the phytohormones indole acetic acid, acetoin, and 2,3-butanediol. Metabolite analysis confirmed by quantitative RT–PCR showed that, the production of acetoin and 2,3-butanediol is induced by the presence of sucrose in the growth medium. Interestingly, both the genetic determinants required for sucrose metabolism and the synthesis of acetoin and 2,3-butanediol are clustered on a genomic island. These findings point to a close interaction between Enterobacter sp. 638 and its poplar host, where the availability of sucrose, a major plant sugar, affects the synthesis of plant growth promoting phytohormones by the endophytic bacterium. The availability of the genome sequence, combined with metabolome and transcriptome analysis, will provide a better understanding of the synergistic interactions between poplar and its growth promoting endophyte Enterobacter sp. 638. This information can be further exploited to

  18. Reduction of chalcogen oxyanions and generation of nanoprecipitates by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Baccolini, Chiara; Francia, Francesco [Department of Pharmacy and Biotechnology, University of Bologna (Italy); Sabatino, Piera [Department of Chemistry G. Ciamician, University of Bologna (Italy); Turner, Raymond J. [Department of Biological Sciences, University of Calgary, Calgary, Alberta (Canada); Zannoni, Davide, E-mail: davide.zannoni@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna (Italy)

    2014-03-01

    Graphical abstract: - Highlights: • R. capsulatus cells produce extracellular chalcogens nanoprecipitates when lawsone is present. • Lawsone acts as a redox mediator from reducing equivalents to tellurite and selenite. • Nanoprecipitates production depends on carbon source and requires metabolically active cells. • Te{sup 0} and Se{sup 0} nanoprecipitates are identified by X-ray diffraction (XRD) spectroscopy. - Abstract: The facultative photosynthetic bacterium Rhodobacter capsulatus is characterized in its interaction with the toxic oxyanions tellurite (Te{sup IV}) and selenite (Se{sup IV}) by a highly variable level of resistance that is dependent on the growth mode making this bacterium an ideal organism for the study of the microbial interaction with chalcogens. As we have reported in the past, while the oxyanion tellurite is taken up by R. capsulatus cells via acetate permease and it is reduced to Te{sup 0} in the cytoplasm in the form of splinter-like black intracellular deposits no clear mechanism was described for Se{sup 0} precipitation. Here, we present the first report on the biotransformation of tellurium and selenium oxyanions into extracellular Te{sup 0} and Se{sup 0}nanoprecipitates (NPs) by anaerobic photosynthetically growing cultures of R. capsulatus as a function of exogenously added redox-mediator lawsone, i.e. 2-hydroxy-1,4-naphthoquinone. The NPs formation was dependent on the carbon source used for the bacterial growth and the rate of chalcogen reduction was constant at different lawsone concentrations, in line with a catalytic role for the redox mediator. X-ray diffraction (XRD) analysis demonstrated the Te{sup 0} and Se{sup 0} nature of the nanoparticles.

  19. Transcriptional changes underlying elemental stoichiometry shifts in a marine heterotrophic bacterium

    Directory of Open Access Journals (Sweden)

    Leong-Keat eChan

    2012-05-01

    Full Text Available Marine bacteria drive the biogeochemical processing of oceanic dissolved organic carbon (DOC, a 750-Tg C reservoir that is a critical component of the global C cycle. Catabolism of DOC is thought to be regulated by the biomass composition of heterotrophic bacteria, as cells maintain a C:N:P ratio of ~50:10:1 during DOC processing. Yet a complicating factor in stoichiometry-based analyses is that bacteria can change the C:N:P ratio of their biomass in response to resource composition. We investigated the physiological mechanisms of resource-driven shifts in biomass stoichiometry in continuous cultures of the marine heterotrophic bacterium Ruegeria pomeroyi (a member of the Roseobacter clade under four element limitation regimes (C, N, P, and S. Microarray analysis indicated that the bacterium scavenged for alternate sources of the scarce element when cells were C-, N-, or P-limited; reworked the ratios of biomolecules when C- and P- limited; and exerted tighter control over import/export and cytoplasmic pools when N-limited. Under S-limitation, a scenario not existing naturally for surface ocean microbes, stress responses dominated transcriptional changes. Resource-driven changes in C:N ratios of up to 2.5-fold and in C:P ratios of up to 6-fold were measured in R. pomeroyi biomass. These changes were best explained if the C and P content of the cells was flexible in the face of shifting resources but N content was not, achieved through the net balance of different transcriptional strategies. The cellular-level metabolic trade-offs that govern biomass stoichiometery in R. pomeroyi may have implications for global carbon cycling. Strong homeostatic responses to N limitation by heterotrophic marine bacteria would intensify competition with autotrophs. Modification of cellular inventories in C- and P-limited heterotrophs would vary the elemental ratio of particulate organic matter sequestered in the deep ocean.

  20. Isolation and characterization of a radiation resistant thermophilic bacterium from radon hot spring

    International Nuclear Information System (INIS)

    Liang Xinle; Yang Long; Zhang Hong; Zhang Lei

    2011-01-01

    A radiation resistant and thermophilic bacterium strain R4-33 was isolated from radon hot spring water samples, pretreated with 60 Co γ-rays and UV irradiation. Tests on morphological, physiological and biochemical characters, fatty acid compositions, (G + C) mol% contents, and 16S rDNA sequencing were conducted. The results showed that strain R4-33 was of rod-shape, Gram-negative, atrichous, and endospore-forming. The optimum growth temperature and pH were 60 ℃ and 7.5, respectively. The strain utilized glucose, maltose and trehalose as carbon sources, and hydrolyzed casein and starch. Its catalase positive. The strain was sensitive to penicillin, neomycin, erythromycin, vancomycin, streptomycin, gentamycin, amikacin and ampicillin. The major cellular fatty acids were C 14:1 (48.8%) and C 15:1 (15.2%). The (G + C) mol% content of DNA was 58.2%. Phylogenetic tree based on 16S rDNA sequence showed R4-33 shared highly similarity to those of species in genus Anoxybacillus, especially to that of Anoxybacillus gonensis (99.5%). Based on the above, the strain R4-33 was proposed to the evolution branch of Anoxybacillus and designated as Anoxybacillu sp. R4-33. The UV and γ-radiation tests showed that the strain R4-33 had an ability of resistance to UV of 396 J/m 2 and 60 Co γ-rays irradiation of 14.0 kGy, indicating that the strain was a radiation resistant and thermophilic bacterium. (authors)

  1. Reduction of Mo(VI) by the bacterium Serratia sp. strain DRY5.

    Science.gov (United States)

    Rahman, M F A; Shukor, M Y; Suhaili, Z; Mustafa, S; Shamaan, N A; Syed, M A

    2009-01-01

    The need to isolate efficient heavy metal reducers for cost effective bioremediation strategy have resulted in the isolation of a potent molybdenum-reducing bacterium. The isolate was tentatively identified as Serratia sp. strain DRY5 based on the Biolog GN carbon utilization profiles and partial 16S rDNA molecular phylogeny. Strain DRY5 produced 2.3 times the amount of Mo-blue than S. marcescens strain Dr.Y6, 23 times more than E. coli K12 and 7 times more than E. cloacae strain 48. Strain DRY5 required 37 degrees C and pH 7.0 for optimum molybdenum reduction. Carbon sources such as sucrose, maltose, glucose and glycerol, supported cellular growth and molybdate reduction after 24 hr of static incubation. The most optimum carbon source that supported reduction was sucrose at 1.0% (w/v). Ammonium sulphate, ammonium chloride, glutamic acid, cysteine, and valine supported growth and molybdate reduction with ammonium sulphate as the optimum nitrogen source at 0. 2% (w/v). Molybdate reduction was optimally supported by 30 mM molybdate. The optimum concentration of phosphate for molybdate reduction was 5 mM when molybdate concentration was fixed at 30 mM and molybdate reduction was totally inhibited at 100 mM phosphate. Mo-blue produced by this strain shows a unique characteristic absorption profile with a maximum peak at 865 nm and a shoulder at 700 nm, Dialysis tubing experiment showed that 95.42% of Mo-blue was found in the dialysis tubing suggesting that the molybdate reduction seen in this bacterium was catalyzed by enzyme(s). The characteristics of isolate DRY5 suggest that it would be useful in the bioremediation ofmolybdenum-containing waste.

  2. A soluble fatty acyl-acyl carrier protein synthetase from the bioluminescent bacterium Vibrio harveyi.

    Science.gov (United States)

    Byers, D M; Holmes, C G

    1990-01-01

    An enzyme catalyzing the ligation of long chain fatty acids to bacterial acyl carrier protein (ACP) has been detected and partially characterized in cell extracts of the bioluminescent bacterium Vibrio harveyi. Acyl-ACP synthetase activity (optimal pH 7.5-8.0) required millimolar concentrations of ATP and Mg2+ and was slightly activated by Ca2+, but was inhibited at high ionic strength and by Triton X-100. ACP from either Escherichia coli (apparent Km = 20 microM) or V. harveyi was used as a substrate. Of the [14C]fatty acids tested as substrates (8-18 carbons), a preference for fatty acids less than or equal to 14 carbons in length was observed. Vibrio harveyi acyl-ACP synthetase appears to be a soluble hydrophilic enzyme on the basis of subcellular fractionation and Triton X-114 phase partition assay. The enzyme was not coinduced with luciferase activity or light emission in vivo during the late exponential growth phase in liquid culture. Acyl-ACP synthetase activity was also detected in extracts from the luminescent bacterium Vibrio fischeri, but not Photobacterium phosphoreum. The cytosolic nature and enzymatic properties of V. harveyi acyl-ACP synthetase indicate that it may have a different physiological role than the membrane-bound activity of E. coli, which has been implicated in phosphatidylethanolamine turnover. Acyl-ACP synthetase activity in V. harveyi could be involved in the intracellular activation and elongation of exogenous fatty acids that occurs in this species or in the reactivation of free myristic acid generated by luciferase.

  3. Virus-Bacterium Interactions in Water and Sediment of West African Inland Aquatic Systems

    Science.gov (United States)

    Bettarel, Yvan; Bouvy, Marc; Dumont, Claire; Sime-Ngando, Télesphore

    2006-01-01

    The ecology of virioplankton in tropical aquatic ecosystems is poorly documented, and in particular, there are no references concerning African continental waters in the literature. In this study, we examined virus-bacterium interactions in the pelagic and benthic zones of seven contrasting shallow inland waters in Senegal, including one hypersaline lake. SYBR Gold-stained samples revealed that in the surface layers of the sites, the numbers of viruses were in the same range as the numbers of viruses reported previously for productive temperate systems. Despite high bacterial production rates, the percentages of visibly infected cells (as determined by transmission electron microscopy) were similar to the lowest percentages (range, 0.3 to 1.1%; mean, 0.5%) found previously at pelagic freshwater or marine sites, presumably because of the local environmental and climatic conditions. Since the percentages of lysogenic bacteria were consistently less than 8% for pelagic and benthic samples, lysogeny did not appear to be a dominant strategy for virus propagation at these sites. In the benthic samples, viruses were highly concentrated, but paradoxically, no bacteria were visibly infected. This suggests that sediment provides good conditions for virus preservation but ironically is an unfavorable environment for proliferation. In addition, given the comparable size distributions of viruses in the water and sediment samples, our results support the paradigm that aquatic viruses are ubiquitous and may have moved between the two compartments of the shallow systems examined. Overall, this study provides additional information about the relevance of viruses in tropical areas and indicates that the intensity of virus-bacterium interactions in benthic habitats may lower than the intensity in the adjacent bodies of water. PMID:16885276

  4. Crassaminicella profunda gen. nov., sp. nov., an anaerobic marine bacterium isolated from deep-sea sediments.

    Science.gov (United States)

    Lakhal, Raja; Pradel, Nathalie; Postec, Anne; Ollivier, Bernard; Cayol, Jean-Luc; Godfroy, Anne; Fardeau, Marie-Laure; Galés, Grégoire

    2015-09-01

    A novel, anaerobic, chemo-organotrophic bacterium, designated strain Ra1766H(T), was isolated from sediments of the Guaymas basin (Gulf of California, Mexico) taken from a depth of 2002  m. Cells were thin, motile, Gram-stain-positive, flexible rods forming terminal endospores. Strain Ra1766H(T) grew at temperatures of 25-45 °C (optimum 30 °C), pH 6.7-8.1 (optimum 7.5) and in a salinity of 5-60 g l(-1) NaCl (optimum 30 g l(-1)). It was an obligate heterotrophic bacterium fermenting carbohydrates (glucose and mannose) and organic acids (pyruvate and succinate). Casamino acids and amino acids (glutamate, aspartate and glycine) were also fermented. The main end products from glucose fermentation were acetate, butyrate, ethanol, H2 and CO2. Sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14  : 0, C16 : 1ω7, C16 : 1ω7 DMA and C16 : 0. The main polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phospholipids. The G+C content of the genomic DNA was 33.7 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Ra1766H(T) was affiliated to cluster XI of the order Clostridiales, phylum Firmicutes. The closest phylogenetic relative of Ra1766H(T) was Geosporobacter subterraneus (94.2% 16S rRNA gene sequence similarity). On the basis of phylogenetic inference and phenotypic properties, strain Ra1766H(T) ( = DSM 27501(T) = JCM 19377(T)) is proposed to be the type strain of a novel species of a novel genus, named Crassaminicella profunda.

  5. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

    Directory of Open Access Journals (Sweden)

    Guangli Wang

    2010-06-01

    Full Text Available Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenylethane (DDT is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95% of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60% of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenylethane (DDD, 2,2-bis(p-chlorophenyl-1,1-dichlorethylene (DDE, and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

  6. Lethal Effect on Bacterium of Decay of Incorporated Radioactive Atoms (3H, 14C, 32P)

    International Nuclear Information System (INIS)

    Apelgot, Sonia

    1968-01-01

    The biological effect of decay of 3 H, 14 C and 32 P incorporated into a bacterium depends on the nature of the organic molecule labelled, on the position of the isotope within it and on the isotope itself. In sum, results obtained to date show that: The decay of 3 H atoms incorporated into certain macromolecules of a bacterium causes sterilization through ionization by the ß - particle emitted; transmutation is of negligible importance. This self-irradiation is comparable in effect with X-rays and is affected in a similar manner by the same factors: temperature, presence of a radioprotector, radiosensitivity of the strain. Decay of 14 C or 32 P atoms incorporated into bacterial DNA is lethal because of the transmutation effect; ionizations produced by emitted ß - particles may be disregarded. Survival curves for 32 P transmutations depend on the experimental conditions. Some of the results obtained with 32 P are similar to those obtained with X-rays, e.g. effects of temperature, radical capture and oxygen, while others are similar to those of u.v. light, e.g., effect of growth conditions. Comparative tests made with 32 P indicate that the recoil energy of transmutation is not the phenomenon responsible for the lethal effect observed. Comparison of the results obtained after X-irradiation or decay of 3 H or 32 P incorporated into the DNA of bacteria of the same strain of E. coli shows that the efficiency of a 32 P transmutation is about four times greater than that of an ionization produced at random within the same DNA. (author) [fr

  7. Draft Genome Sequence of Enterobacter sp. Sa187, an Endophytic Bacterium Isolated from the Desert Plant Indigofera argentea

    KAUST Repository

    Lafi, Feras Fawzi; Alam, Intikhab; Geurts, Rene; Bisseling, Ton; Bajic, Vladimir B.; Hirt, Heribert; Saad, Maged

    2017-01-01

    Enterobacter sp. Sa187 is a plant endophytic bacterium, isolated from root nodules of the desert plant Indigofera argentea, collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of Sa187, highlighting several genes involved in plant growth–promoting activity and environmental adaption.

  8. Draft genome sequence of Enterobacter sp. Sa187, an endophytic bacterium isolated from the desert plant Indigofera argentea

    NARCIS (Netherlands)

    Lafi, Feras F.; Alam, Intikhab; Geurts, Rene; Bisseling, Ton; Bajic, Vladimir B.; Hirt, Heribert; Saad, Maged M.

    2017-01-01

    Enterobacter sp. Sa187 is a plant endophytic bacterium, isolated from root nodules of the desert plant Indigofera argentea, collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of Sa187, highlighting several genes involved in plant growth-promoting activity and

  9. A Comparative biochemical study on two marine endophytes, Bacterium SRCnm and Bacillus sp. JS, Isolated from red sea algae.

    Science.gov (United States)

    Ahmed, Eman Fadl; Hassan, Hossam Mokhtar; Rateb, Mostafa Ezzat; Abdel-Wahab, Noha; Sameer, Somayah; Aly Taie, Hanan Anwar; Abdel-Hameed, Mohammed Sayed; Hammouda, Ola

    2016-01-01

    Two marine endophytic bacteria were isolated from the Red Sea algae; a red alga; Acanthophora dendroides and the brown alga Sargassum sabrepandum. The isolates were identified based on their 16SrRNA sequences as Bacterium SRCnm and Bacillus sp. JS. The objective of this study was to investigate the potential anti-microbial and antioxidant activities of the extracts of the isolated bacteria grown in different nutrient conditions. Compared to amoxicillin (25μg/disk) and erythromycin (15μg/disk), the extracts of Bacterium SRCn min media II, III, IV and V were potent inhibitors of the gram-positive bacterium Sarcina maxima even at low concentrations. Also, the multidrug resistant Staphylococcus aureus(MRSA) was more sensitive to the metabolites produced in medium (II) of the same endophyte than erythromycin (15μg/disk). A moderate activity of the Bacillus sp. JS extracts of media I and II was obtained against the same pathogen. The total compounds (500ug/ml) of both isolated endophytes showed moderate antioxidant activities (48.9% and 46.1%, respectively). LC/MS analysis of the bacterial extracts was carried out to investigate the likely natural products produced. Cyclo(D-cis-Hyp-L-Leu), dihydrosphingosine and 2-Amino-1,3-hexadecanediol were identified in the fermentation medium of Bacterium SRCnm, whereas cyclo (D-Pro-L-Tyr) and cyclo (L-Leu-L-Pro) were the suggested compounds of Bacillus sp. JS.

  10. First Insights into the Genome Sequence of Clostridium thermopalmarium DSM 5974, a Butyrate-Producing Bacterium Isolated from Palm Wine.

    Science.gov (United States)

    Poehlein, Anja; Hettwer, Eva; Mohnike, Lennart; Daniel, Rolf

    2018-04-26

    Clostridium thermopalmarium is a moderate thermophilic, rod-shaped, and endospore-forming bacterium, which was isolated from palm wine in Senegal. Butyrate is produced from a broad variety of sugar substrates. Here, we present the draft genome sequence of C. thermopalmarium DSM 5974 (2.822 Mb) containing 2,665 predicted protein-encoding genes. Copyright © 2018 Poehlein et al.

  11. ‘Lactobacillus raoultii’ sp. nov., a new bacterium isolated from the vaginal flora of a woman with bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    B. Nicaise

    2018-01-01

    Full Text Available We report the isolation of a new bacterium species, ‘Lactobacillus raoultii’ strain Marseille P4006 (CSUR P4006, isolated from a vaginal sample of a 45-year-old woman with bacterial vaginosis. Keywords: Bacterial vaginosis, culturomics, emerging bacteria, human microbiota, Lactobacillus raoultii, vaginal microbiota

  12. Antioxidants keep the potentially probiotic but highly oxygen-sensitive human gut bacterium Faecalibacterium prausnitzii alive at ambient air

    NARCIS (Netherlands)

    Khan, M. Tanweer; van Dijl, Jan Maarten; Harmsen, Hermie J M

    2014-01-01

    The beneficial human gut microbe Faecalibacterium prausnitzii is a 'probiotic of the future' since it produces high amounts of butyrate and anti-inflammatory compounds. However, this bacterium is highly oxygen-senstive, making it notoriously difficult to cultivate and preserve. This has so far

  13. Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CFL1, a Lactic Acid Bacterium Isolated from French Handcrafted Fermented Milk

    OpenAIRE

    Meneghel, Julie; Dugat-Bony, Eric; Irlinger, Fran?oise; Loux, Valentin; Vidal, Marie; Passot, St?phanie; B?al, Catherine; Layec, S?verine; Fonseca, Fernanda

    2016-01-01

    Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a lactic acid bacterium widely used for the production of yogurt and cheeses. Here, we report the genome sequence of L. bulgaricus CFL1 to improve our knowledge on its stress-induced damages following production and end-use processes.

  14. Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

    DEFF Research Database (Denmark)

    Ravnskov, S.; Larsen, J.; Jakobsen, I.

    2002-01-01

    The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus ...

  15. Microbacter margulisiae gen. nov., sp. nov., a novel propionigenic bacterium isolated from sediments of an acid rock drainage pond

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Luis Sanz, J.; Stams, A.J.M.

    2014-01-01

    A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4-0.6 x 1-1.7 µm), non-motile and non-spore forming rods. Cells possessed a Gram-negative cell wall structure and were vancomycin

  16. Differential proteome and cellular adhesion analyses of the probiotic bacterium Lactobacillus acidophilus NCFM grown on raffinose - an emerging prebiotic

    DEFF Research Database (Denmark)

    Celebioglu, Hasan Ufuk; Hansen, Morten Ejby; Majumder, Avishek

    2016-01-01

    Whole cell and surface proteomes were analyzed together with adhesive properties of the probiotic bacterium Lactobacillus acidophilus NCFM (NCFM) grown on the emerging prebiotic raffinose, exemplifying a synbiotic. Adhesion of NCFM to mucin and intestinal HT-29 cells increased three-fold after...

  17. Complete genome sequences of two strains of the meat spoilage bacterium Brochothrix thermosphacta isolated from ground chicken

    Science.gov (United States)

    Brochothrix thermosphacta is an important meat spoilage bacterium. Here we report the genome sequences of two strains of B. thermosphacta isolated from ground chicken. The genome sequences were determined using long-read PacBio single-molecule real-time (SMRT©) technology and are the first complete ...

  18. Locked chromophore analogs reveal that photoactive yellow protein regulates biofilm formation in the deep sea bacterium Idiomarina loihiensis

    NARCIS (Netherlands)

    van der Horst, M.A.; Stalcup, T.P.; Kaledhonkar, S.; Kumauchi, M.; Hara, M.; Xie, A.; Hellingwerf, K.J.; Hoff, W.D.

    2009-01-01

    Idiomarina loihiensis is a heterotrophic deep sea bacterium with no known photobiology. We show that light suppresses biofilm formation in this organism. The genome of I. loihiensis encodes a single photoreceptor protein: a homologue of photoactive yellow protein (PYP), a blue light receptor with

  19. Lactobacillus diolivorans sp nov., a 1,2-propanediol-degrading bacterium isolated from aerobically stable maize silage

    NARCIS (Netherlands)

    Krooneman, J; Faber, F; Alderkamp, AC; Elferink, SJHWO; Driehuis, F; Cleenwerck, [No Value; Swings, J; Gottschal, JC; Vancanneyt, M

    Inoculation of maize silage with Lactobacillus buchneri (5 x 10(5) c.f.u. g(-1) of maize silage) prior to ensiling results in the formation of aerobically stable silage. After 9 months, lactic acid bacterium counts are approximately 10(10) c.f.u. g(-1) in these treated silages. An important

  20. Thermotoga lettingae sp. nov. : a novel thermophilic, methanol-degrading bacterium isolated from a thermophilic anaerobic reactor

    NARCIS (Netherlands)

    Balk, M.; Weijma, J.; Stams, A.J.M.

    2002-01-01

    A novel, anaerobic, non-spore-forming, mobile, Gram-negative, thermophilic bacterium, strain TMO(T), was isolated from a thermophilic sulfate-reducing bioreactor operated at 65 degrees C with methanol as the sole substrate. The G C content of the DNA of strain TMO(T) was 39.2 molÐThe optimum pH,

  1. Whole-Genome Shotgun Sequence of the Keratinolytic Bacterium Lysobacter sp. A03, Isolated from the Antarctic Environment

    OpenAIRE

    Pereira, Jamile Queiroz; Ambrosini, Adriana; Sant?Anna, Fernando Hayashi; Tadra-Sfeir, Michele; Faoro, Helisson; Pedrosa, F?bio Oliveira; Souza, Emanuel Maltempi; Brandelli, Adriano; Passaglia, Luciane M. P.

    2015-01-01

    Lysobacter sp. strain A03 is a protease-producing bacterium isolated from decomposing-penguin feathers collected in the Antarctic environment. This strain has the ability to degrade keratin at low temperatures. The A03 genome sequence provides the possibility of finding new genes with biotechnological potential to better understand its cold-adaptation mechanism and survival in cold environments.

  2. Genome Sequence of the Enterobacter mori Type Strain, LMG 25706, a Pathogenic Bacterium of Morus alba L. ▿

    Science.gov (United States)

    Zhu, Bo; Zhang, Guo-Qing; Lou, Miao-Miao; Tian, Wen-Xiao; Li, Bin; Zhou, Xue-Ping; Wang, Guo-Feng; Liu, He; Xie, Guan-Lin; Jin, Gu-Lei

    2011-01-01

    Enterobacter mori is a plant-pathogenic enterobacterium responsible for the bacterial wilt of Morus alba L. Here we present the draft genome sequence of the type strain, LMG 25706. To the best of our knowledge, this is the first genome sequence of a plant-pathogenic bacterium in the genus Enterobacter. PMID:21602328

  3. Characterization of cytochrome P450 monooxygenase CYP154H1 from the thermophilic soil bacterium Thermobifida fusca

    NARCIS (Netherlands)

    Schallmey, Anett; den Besten, Gijs; Teune, Ite G. P.; Kembaren, Roga F.; Janssen, Dick B.

    Cytochrome P450 monooxygenases are valuable biocatalysts due to their ability to hydroxylate unactivated carbon atoms using molecular oxygen. We have cloned the gene for a new cytochrome P450 monooxygenase, named CYP154H1, from the moderately thermophilic soil bacterium Thermobifida fusca. The

  4. Draft Genome Sequence of Enterobacter sp. Sa187, an Endophytic Bacterium Isolated from the Desert Plant Indigofera argentea

    KAUST Repository

    Lafi, Feras Fawzi

    2017-02-17

    Enterobacter sp. Sa187 is a plant endophytic bacterium, isolated from root nodules of the desert plant Indigofera argentea, collected from the Jizan region of Saudi Arabia. Here, we report the genome sequence of Sa187, highlighting several genes involved in plant growth–promoting activity and environmental adaption.

  5. Complete genome of Pandoraea pnomenusa RB-38, an oxalotrophic bacterium isolated from municipal solid waste landfill site.

    Science.gov (United States)

    Lim, Yan-Lue; Ee, Robson; Yong, Delicia; Tee, Kok-Keng; Yin, Wai-Fong; Chan, Kok-Gan

    2015-11-20

    Pandoraea pnomenusa RB-38 is a bacterium isolated from a former sanitary landfill site. Here, we present the complete genome of P. pnomenusa RB38 in which an oxalate utilization pathway was identified. The genome analysis suggested the potential of this strain as an effective biocontrol agent against oxalate-producing phytopathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Draft Genome Sequence of Caenibacillus caldisaponilyticus B157T, a Thermophilic and Phospholipase-Producing Bacterium Isolated from Acidulocompost

    Science.gov (United States)

    Tsujimoto, Yoshiyuki; Saito, Ryo; Sahara, Takehiko; Kimura, Nobutada; Tsuruoka, Naoki; Shigeri, Yasushi

    2017-01-01

    ABSTRACT Caenibacillus caldisaponilyticus B157T (= NBRC 111400T = DSM 101100T), in the family Sporolactobacillaceae, was isolated from acidulocompost as a thermophilic and phospholipid-degrading bacterium. Here, we report the 3.36-Mb draft genome sequence, with a G+C content of 51.8%, to provide the genetic information coding for phospholipases. PMID:28360164

  7. Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

    Science.gov (United States)

    da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall'Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves; Gonçalves, Evonnildo Costa

    2016-05-19

    Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here. Copyright © 2016 da Silva et al.

  8. Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria

    OpenAIRE

    da Silva, F?bio Daniel Flor?ncio; Lima, Alex Ranieri Jer?nimo; Moraes, Pablo Henrique Gon?alves; Siqueira, Andrei Santos; Dall?Agnol, Leonardo Teixeira; Bara?na, Anna Rafaella Ferreira; Martins, Luisa Car?cio; Oliveira, Karol Guimar?es; de Lima, Clayton Pereira Silva; Nunes, M?rcio Roberto Teixeira; Vianez-J?nior, Jo?o L?dio Silva Gon?alves; Gon?alves, Evonnildo Costa

    2016-01-01

    Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here.

  9. Nonlinear effect of irradiance on photoheterotrophic activity and growth of the aerobic anoxygenic phototrophic bacterium Dinoroseobacter shibae

    Czech Academy of Sciences Publication Activity Database

    Piwosz, Kasia; Kaftan, David; Dean, Jason; Šetlík, Jiří; Koblížek, Michal

    2018-01-01

    Roč. 20, č. 2 (2018), s. 724-733 ISSN 1758-2229 R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : PHOTOSYNTHETIC BACTERIUM * LEUCINE INCORPORATION * SOLAR-RADIATION Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.363, year: 2016

  10. Complete genome sequence of Nitrosomonas sp. Is79, an ammonia oxidizing bacterium adapted to low ammonium concentrations

    NARCIS (Netherlands)

    Bollmann, A.; Sedlacek, C.J.; Norton, J.; Laanbroek, H.J.; Suwa, Y.; Stein, L.Y.; Klotz, M.G.; Arp, D.; Sayavedra-Soto, L.; Lu, M.; Bruce, D.; Detter, C.; Tapia, R.; Han, J.; Woyke, T.; Lucas, S.; Pitluck, S.; Pennacchio, L.; Nolan, M.; Land, M.L.; Huntemann, M.; Deshpande, S.; Han, C.; Chen, A.; Kyrpides, N.; Mavromatis, K.; Markowitz, V.; Szeto, E.; Ivanova, N.; Mikhailova, N.; Pagani, I.; Pati, A.; Peters, L.; Ovchinnikova, G.; Goodwin, L.

    2013-01-01

    Nitrosomonas sp. Is79 is a chemolithoautotrophic ammonia-oxidizing bacterium that belongs to the family Nitrosomonadaceae within the phylum Proteobacteria. Ammonia oxidation is the first step of nitrification, an important process in the global nitrogen cycle ultimately resulting in the production

  11. Draft Genome Sequence of Lactobacillus delbrueckii subsp. bulgaricus CFL1, a Lactic Acid Bacterium Isolated from French Handcrafted Fermented Milk.

    Science.gov (United States)

    Meneghel, Julie; Dugat-Bony, Eric; Irlinger, Françoise; Loux, Valentin; Vidal, Marie; Passot, Stéphanie; Béal, Catherine; Layec, Séverine; Fonseca, Fernanda

    2016-03-03

    Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) is a lactic acid bacterium widely used for the production of yogurt and cheeses. Here, we report the genome sequence of L. bulgaricus CFL1 to improve our knowledge on its stress-induced damages following production and end-use processes. Copyright © 2016 Meneghel et al.

  12. ["Candidatus contubernalis alkalaceticum," an obligately syntrophic alkaliphilic bacterium capable of anaerobic acetate oxidation in a coculture with Desulfonatronum cooperativum].

    Science.gov (United States)

    Zhilina, T N; Zavarzina, D G; Kolganova, T V; Turova, T P; Zavarzin, G A

    2005-01-01

    From the silty sediments of the Khadyn soda lake (Tuva), a binary sulfidogenic bacterial association capable of syntrophic acetate oxidation at pH 10.0 was isolated. An obligately syntrophic, gram-positive, spore-forming alkaliphilic rod-shaped bacterium performs acetate oxidation in a syntrophic association with a hydrogenotrophic, alkaliphilic sulfate-reducing bacterium; the latter organism was previously isolated and characterized as the new species Desulfonatronum cooperativum. Other sulfate-reducing bacteria of the genera Desulfonatronum and Desulfonatronovibrio can also act as the hydrogenotrophic partner. Apart from acetate, the syntrophic culture can oxidize ethanol, propanol, isopropanol, serine, fructose, and isobutyric acid. Selective amplification of 16S rRNA gene fragments of the acetate-utilizing syntrophic component of the binary culture was performed; it was found to cluster with clones of uncultured gram-positive bacteria within the family Syntrophomonadaceae. The acetate-oxidizing bacterium is thus the first representative of this cluster obtained in a laboratory culture. Based on its phylogenetic position, the new acetate-oxidizing syntrophic bacterium is proposed to be assigned, in a Candidate status, to a new genus and species: "Candidatus Contubernalis alkalaceticum."

  13. Draft Genome Sequence of the Soil Bacterium Burkholderia terrae Strain BS001, Which Interacts with Fungal Surface Structures

    DEFF Research Database (Denmark)

    Nazir, Rashid; Hansen, Martin A.; Sorensen, Soren

    2012-01-01

    Burkholderia terrae BS001 is a soil bacterium which was originally isolated from the mycosphere of the ectomycorrhizal fungus Laccaria proxima. It exhibits a range of fungus-interacting traits which reveal its propensity to actively interact at fungal interfaces. Here, we present the approximately...

  14. Successful split thickness skin grafting in the presence of heavy colonisation with rare bacterium Aeromonas hydrophila: A case report

    Directory of Open Access Journals (Sweden)

    S. Koschel

    2017-09-01

    Discussion: Contemporary literature is yet to make the distinction between colonisation and infection of this bacterium, with clinicians relying solely on the presence of infective stigmata and serum analysis. However, this is a critically important distinction when ascertaining the likelihood of success of wound healing.

  15. Extreme weather events and infectious disease outbreaks.

    Science.gov (United States)

    McMichael, Anthony J

    2015-01-01

    Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and 'pestilence' associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations.

  16. Extremely low temperature properties of epoxy GFRP

    International Nuclear Information System (INIS)

    Kadotani, Kenzo; Nagai, Matao; Aki, Fumitake.

    1983-01-01

    The examination of fiber-reinforced plastics, that is, plastics such as epoxy, polyester and polyimide reinforced with high strength fibers such as glass, carbon, boron and steel, for extremely low temperature use began from the fuel tanks of rockets. Therafter, the trial manufacture of superconducting generators and extremely low temperature transformers and the manufacture of superconducting magnets for nuclear fusion experimental setups became active, and high performance FRPs have been adopted, of which the extremely low temperature properties have been sufficiently grasped. Recently, the cryostats made of FRPs have been developed, fully utilizing such features of FRPs as high strength, high rigidity, non-magnetic material, insulation, low heat conductivity, light weight and the freedom of molding. In this paper, the mechanical properties at extremely low temperature of the plastic composite materials used as insulators and structural materials for extremely low temperature superconducting equipment is outlined, and in particular, glass fiber-reinforced epoxy laminates are described somewhat in detail. The fracture strain of GFRP at extremely low temperature is about 1.3 times as large as that at room temperature, but at extremely low temperature, clear cracking occurred at 40% of the fracture strain. The linear thermal contraction of GFRP showed remarkable anisotropy. (Kako, I.)

  17. Performance testing of extremity dosimeters, Study 2

    International Nuclear Information System (INIS)

    Harty, R.; Reece, W.D.; Hooker, C.D.

    1990-04-01

    The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

  18. Probabilistic analysis of extreme wind events

    Energy Technology Data Exchange (ETDEWEB)

    Chaviaropoulos, P.K. [Center for Renewable Energy Sources (CRES), Pikermi Attikis (Greece)

    1997-12-31

    A vital task in wind engineering and meterology is to understand, measure, analyse and forecast extreme wind conditions, due to their significant effects on human activities and installations like buildings, bridges or wind turbines. The latest version of the IEC standard (1996) pays particular attention to the extreme wind events that have to be taken into account when designing or certifying a wind generator. Actually, the extreme wind events within a 50 year period are those which determine the ``static`` design of most of the wind turbine components. The extremes which are important for the safety of wind generators are those associated with the so-called ``survival wind speed``, the extreme operating gusts and the extreme wind direction changes. A probabilistic approach for the analysis of these events is proposed in this paper. Emphasis is put on establishing the relation between extreme values and physically meaningful ``site calibration`` parameters, like probability distribution of the annual wind speed, turbulence intensity and power spectra properties. (Author)

  19. Evidence of carbon fixation pathway in a bacterium from candidate phylum SBR1093 revealed with genomic analysis.

    Directory of Open Access Journals (Sweden)

    Zhiping Wang

    Full Text Available Autotrophic CO2 fixation is the most important biotransformation process in the biosphere. Research focusing on the diversity and distribution of relevant autotrophs is significant to our comprehension of the biosphere. In this study, a draft genome of a bacterium from candidate phylum SBR1093 was reconstructed with the metagenome of an industrial activated sludge. Based on comparative genomics, this autotrophy may occur via a newly discovered carbon fixation path, the hydroxypropionate-hydroxybutyrate (HPHB cycle, which was demonstrated in a previous work to be uniquely possessed by some genera from Archaea. This bacterium possesses all of the thirteen enzymes required for the HPHB cycle; these enzymes share 30∼50% identity with those in the autotrophic species of Archaea that undergo the HPHB cycle and 30∼80% identity with the corresponding enzymes of the mixotrophic species within Bradyrhizobiaceae. Thus, this bacterium might have an autotrophic growth mode in certain conditions. A phylogenetic analysis based on the 16S rRNA gene reveals that the phylotypes within candidate phylum SBR1093 are primarily clustered into 5 clades with a shallow branching pattern. This bacterium is clustered with phylotypes from organically contaminated environments, implying a demand for organics in heterotrophic metabolism. Considering the types of regulators, such as FnR, Fur, and ArsR, this bacterium might be a facultative aerobic mixotroph with potential multi-antibiotic and heavy metal resistances. This is the first report on Bacteria that may perform potential carbon fixation via the HPHB cycle, thus may expand our knowledge of the distribution and importance of the HPHB cycle in the biosphere.

  20. [Injury mechanisms in extreme violence settings].

    Science.gov (United States)

    Arcaute-Velazquez, Fernando Federico; García-Núñez, Luis Manuel; Noyola-Vilallobos, Héctor Faustino; Espinoza-Mercado, Fernando; Rodríguez-Vega, Carlos Eynar

    2016-01-01

    Extreme violence events are consequence of current world-wide economic, political and social conditions. Injury patterns found among victims of extreme violence events are very complex, obeying several high-energy injury mechanisms. In this article, we present the basic concepts of trauma kinematics that regulate the clinical approach to victims of extreme violence events, in the hope that clinicians increase their theoretical armamentarium, and reflecting on obtaining better outcomes. Copyright © 2016. Published by Masson Doyma México S.A.