| hipip oxido-reductase activity in membranes from aerobically grown cells of the facultative phototroph rhodoferax fermentans. | the role of the periplasmically located, water-soluble, hipip (high-potential iron-sulfur protein) in the respiratory chain of the facultative phototroph rhodoferax fermentans has been examined. the oxidized hipip is reduced by succinate-dependent respiration via the bc1 complex, this reaction being inhibited by myxothiazol and/or stigmatellin. the reduced hipip can be oxidized by the membrane-bound cytochrome oxidase, this reaction being inhibited by 0.1 mm cyanide. we conclude that aerobically ... | 1995 | 7498498 |
| phylogenetic affiliations of rhodoferax fermentans and related species of phototrophic bacteria as determined by automated 16s rdna sequencing. | 16s rdna sequences of strains of rhodoferax fermentans were analyzed and compared with those of species of the genera rubrivivax and rhodocyclus. approximately 1.5-kb fragments of 16s rdna from crude cell lysates were amplified by the polymerase chain reaction (pcr) and sequenced directly by using tth dna polymerase with the linear pcr sequencing protocol, followed by on-line detection with an automated laser fluorescent dna sequencer. pairwise sequence comparisons and distance matrix tree analy ... | 1994 | 7506088 |
| 2,4-dichlorophenoxyacetic acid-degrading bacteria contain mosaics of catabolic genes. | dna from 32 2,4-dichlorophenoxyacetic acid (2,4-d)-degrading bacteria from diverse locations was probed with the first three genes of the well-known 2,4-d degradation pathway found in alcaligenes eutrophus jmp134(pjp4). the majority of strains did not show high levels of homology to the first three genes of the 2,4-d degradation pathway, tfda, -b, and -c. most strains showed combinations of tfda-, b-, and c-like elements that exhibited various degrees of homology to the gene probes. strains havi ... | 1995 | 7574638 |
| isolation, characterization, and functional role of the high-potential iron-sulfur protein (hipip) from rhodoferax fermentans. | a new high-potential iron-sulfur protein (hipip) has been isolated and purified to homogeneity from the soluble fraction obtained from light-grown cells of the facultative photoheterotrophic bacterium rhodoferax fermentans. the new protein was identified as a hipip by virtue of its molecular properties such as the molecular mass (m(r) = 8.7 kda), the fe/protein ratio (3.8 +/- 0.2), the reduction potential (em,7 = +351 mv), the electronic spectrum of the reduced and the oxidized protein, and the ... | 1995 | 7574702 |
| the high potential iron-sulfur protein (hipip) from rhodoferax fermentans is competent in photosynthetic electron transfer. | the functional role of the high potential iron-sulfur protein (hipip) from the photosynthetic bacterium rhodoferax fermentans was investigated. we demonstrated that the hipip increased the rate of light-induced oxygen reduction mediated by the photosynthetic reaction center (rc); this stimulation reached half-saturation at [hipip]/[rc] ca. 15. the capability of the hipip in delivering electrons to the reaction center of rhodoferax fermentans was demonstrated through kinetic spectrophotometry of ... | 1995 | 8001683 |
| 1h nmr of high-potential iron-sulfur protein from the purple non-sulfurbacterium rhodoferax fermentans. | oxidized and reduced forms of high-potential iron-sulfur protein (hipip) from the purple non-sulfur photosynthetic bacterium rhodoferax fermentans have been characterized using 1h-nmr spectroscopy. pairwise and sequence-specific assignments of hyperfine-shifted 1h-nmr signals to protons of cysteine residues bound to the [4fe-4s]3+/2+ cluster have been performed using one-dimensional noe and exchange spectroscopy experiments. 1h-nmr hyperfine shifts and relaxation rates of cluster-bound cys beta- ... | 1996 | 8612609 |
| kinetics of photo-induced electron transfer from high-potential iron-sulfur protein to the photosynthetic reaction center of the purple phototroph rhodoferax fermentans. | the kinetics of photo-induced electrontransfer from high-potential iron-sulfur protein (hipip) to the photosynthetic reaction center (rc) of the purple phototroph rhodoferarfermentans were studied. the rapid photooxidation of heme c-556 belonging to rc is followed, in the presence of hipip, by a slower reduction having a second-order rate constant of 4.8 x 10(7) m(-1) x s(-1). the limiting value of kobs at high hipip concentration is 95 s(-1). the amplitude of this slow process decreases with in ... | 1996 | 8692932 |
| polaromonas vacuolata gen. nov., sp. nov., a psychrophilic, marine, gas vacuolate bacterium from antarctica. | several strains of a novel heterotrophic gas vacuolate bacterium were isolated from antarctic marine waters. the results of phylogenetic analyses in which 16s ribosomal dan sequencing was used, coupled with phenotypic tests, indicated that strain 34-p(t) (t = type strain) belongs to a new genus and species of the beta subgroup of the proteobacteria, for which the name polaromonas vacuolata is proposed. although the other four strains studied probably belong to this new species, dna-dna hybridiza ... | 1996 | 8782696 |
| the primary structure of rhodoferax fermentans high-potential iron-sulfur protein, an electron donor to the photosynthetic reaction center. | the complete amino acid sequence of rhodoferax fermentans high-potential iron-sulfur protein (hipip), which is known to be an efficient electron donor to the photosynthetic reaction center, has been determined using both n-terminal and c-terminal analyses. the sequence contains 75 residues, with 11 positive charges, 10 negative charges, and one histidine residue. the molecular mass of apo-hipip, determined by electrospray ionization mass spectrometry, is 7849.64 da. multiple sequence alignment, ... | 1997 | 9119002 |
| on the role of high-potential iron-sulfur proteins and cytochromes in the respiratory chain of two facultative phototrophs | the capability of high potential iron-sulfur proteins (hipips) and soluble cytochromes to shuttle electrons between the bc1 complex and the terminal oxidase in aerobically grown cells of rhodoferax fermentans and rhodospirillum salinarum, two facultative phototrophs, was evaluated. in rs. salinarum, hipip and a c-type cytochrome (alpha-band at 550 nm, em,7=+290 mv) are both involved in the electron transfer step from the bc1 complex to the terminal oxidase. kinetic studies indicate that cytochro ... | 1999 | 10076014 |
| rhodoferax antarcticus sp. nov., a moderately psychrophilic purple nonsulfur bacterium isolated from an antarctic microbial mat. | a new species of purple nonsulfur bacteria isolated from an antarctic microbial mat is described. the organism, designated strain ant.br, was mildly psychrophilic, growing optimally at 15-18 degrees c with a growth temperature range of 0-25 degrees c. cells of strain ant.br were highly motile curved rods and spirals, contained bacteriochlorophyll a, and showed a multicomponent in vivo absorption spectrum. a specific phylogenetic relationship was observed between strain ant.br and the purple bact ... | 2000 | 10816045 |
| relationships between microbial community structure and hydrochemistry in a landfill leachate-polluted aquifer. | knowledge about the relationship between microbial community structure and hydrogeochemistry (e.g., pollution, redox and degradation processes) in landfill leachate-polluted aquifers is required to develop tools for predicting and monitoring natural attenuation. in this study analyses of pollutant and redox chemistry were conducted in parallel with culture-independent profiling of microbial communities present in a well-defined aquifer (banisveld, the netherlands). degradation of organic contami ... | 2001 | 11571165 |
| physiological and genetic characteristics of two bacterial strains utilizing phenoxypropionate and phenoxyacetate herbicides. | two strains, rhodoferax sp. p230 and delftia (comamonas) acidovorans mci, have previously been shown to carry activities for the degradation of the two enantiomers of (rs)-2-(2,4-dichlorophenoxy-)propionate (dichlorprop) and (rs)-2-(4-chloro-2-methylphenoxy-)propionate (mecoprop) and, in addition, are capable of degrading phenoxyacetate derivatives 2.4-dichlorophenoxyacetate (2,4-d) and 4-chloro-2-methylphenoxyacetate (mcpa). metabolism of the herbicides is initiated by alpha-ketoglutarate-depen ... | 2001 | 11572451 |
| genotypic and phenotypic diversity within species of purple nonsulfur bacteria isolated from aquatic sediments. | to assess the extent of genotypic and phenotypic diversity within species of purple nonsulfur bacteria found in aquatic sediments, a total of 128 strains were directly isolated from agar plates that had been inoculated with sediment samples from haren and de biesbosch in the netherlands. all isolates were initially characterized by box-pcr genomic dna fingerprinting, and 60 distinct genotypes were identified. analyses of 16s rrna gene sequences of representatives of each genotype showed that fiv ... | 2002 | 12089030 |
| complex ii from phototrophic purple bacterium rhodoferax fermentans displays rhodoquinol-fumarate reductase activity. | it has long been accepted that bacterial quinol-fumarate reductase (qfr) generally uses a low-redox-potential naphthoquinone, menaquinone (mk), as the electron donor, whereas mitochondrial qfr from facultative and anaerobic eukaryotes uses a low-redox-potential benzoquinone, rhodoquinone (rq), as the substrate. in the present study, we purified novel complex ii from the rq-containing phototrophic purple bacterium, rhodoferax fermentans that exhibited high rhodoquinol-fumarate reductase activity ... | 2003 | 12694200 |
| rhodoferax ferrireducens sp. nov., a psychrotolerant, facultatively anaerobic bacterium that oxidizes acetate with the reduction of fe(iii). | to further investigate the diversity of micro-organisms capable of conserving energy to support growth from dissimilatory fe(iii) reduction, fe(iii)-reducing micro-organisms were enriched and isolated from subsurface sediments collected in oyster bay, va, usa. a novel isolate, designated t118(t), was recovered in a medium with lactate as the sole electron donor and fe(iii) as the sole electron acceptor. cells of t1 18(t) were gram-negative, motile, short rods with a single polar flagellum. strai ... | 2003 | 12807184 |
| diversity and seasonal variability of beta-proteobacteria in biofilms of polluted rivers: analysis by temperature gradient gel electrophoresis and cloning. | the beta-subgroup of the proteobacteria has been shown to be important in aquatic habitats and was investigated in depth here by molecular 16s rrna techniques in biofilms of the elbe river and its polluted tributary, the spittelwasser river. the bacterial 16s rrna genes were cloned from each site, screened for beta-proteobacterial clones and sequenced. river biofilm clones from both rivers grouped into 9 clusters (rbfs). rbfs 1, 2, and 3 fell into the recently described betai cluster of cosmopol ... | 2003 | 12902230 |
| structure of rhodoferax fermentans high-potential iron-sulfur protein solved by mad. | the crystal structure of rhodoferax fermentans high-potential iron protein (hipip) has been solved by mad methods using the anomalous signal from the fe atoms in the [fe(4)s(4)] cluster present in the protein and refined to a resolution of 1.45 a. the peptide chain is well defined except in the n- and c-terminal areas. the structure of the protein reveals the presence of three helical fragments, a small beta-sheet and several turns, with the [fe(4)s(4)] cluster being located close to a surface p ... | 2003 | 12925788 |
| electricity generation by direct oxidation of glucose in mediatorless microbial fuel cells. | abundant energy, stored primarily in the form of carbohydrates, can be found in waste biomass from agricultural, municipal and industrial sources as well as in dedicated energy crops, such as corn and other grains. potential strategies for deriving useful forms of energy from carbohydrates include production of ethanol and conversion to hydrogen, but these approaches face technical and economic hurdles. an alternative strategy is direct conversion of sugars to electrical power. existing transiti ... | 2003 | 12960964 |
| structure and seasonal dynamics of hyporheic zone microbial communities in free-stone rivers of the western united states. | the hyporheic zone of a river is characterized by being nonphotic, exhibiting chemical/redox gradients, and having a heterotrophic food web based on the consumption of organic carbon entrained from surface waters. hyporheic microbial communities constitute the base of food webs in these environments and are important for maintaining a functioning lotic ecosystem. while microbial communities of rivers dominated by fine-grained sediments are relatively well studied, little is known about the struc ... | 2003 | 14708745 |
| culturable bacteria in subglacial sediments and ice from two southern hemisphere glaciers. | viable prokaryotes have been detected in basal sediments beneath the few northern hemisphere glaciers that have been sampled for microbial communities. however, parallel studies have not previously been conducted in the southern hemisphere, and subglacial environments in general are a new and underexplored niche for microbes. unfrozen subglacial sediments and overlying glacier ice samples collected aseptically from the fox glacier and franz josef glacier in the southern alps of new zealand now h ... | 2004 | 14994176 |
| high-diversity biofilm for the oxidation of sulfide-containing effluents. | in the present work, we describe for the first time the utilization of a complex microbial biofilm for the treatment of sulfide-containing effluents. a non-aerated packed-column reactor was inoculated with anoxic lake sediment and exposed to light. a biofilm developed in the column and showed a stable oxidation performance for several weeks. microbial species composition was analyzed by microscopy, pigment analysis and a bacterial 16s rrna gene clone library. colorless sulfur bacteria, green alg ... | 2004 | 14997354 |
| bioelectric power generation. | in the recent article by chaudhuri and lovley, a fuel cell is described in which a microorganism, rhodoferax ferrireducens, is used to oxidize glucose to carbon dioxide at neutral ph. this reaction occurs via direct bioelectrocatalysis: the microorganism uses the anode itself as the terminal oxidant to which liberated electrons are transferred, and does so with 83% efficiency. these findings are significant because they demonstrate a new approach for harvesting energy from the environment using ... | 2004 | 15043037 |
| a gas vesiculate planktonic strain of the purple non-sulfur bacterium rhodoferax antarcticus isolated from lake fryxell, dry valleys, antarctica. | a moderately psychrophilic purple non-sulfur bacterium, rhodoferax antarcticus strain fryx1, is described. strain fryx1 was isolated from the water column under the ice of the permanently frozen lake fryxell, antarctica. cells of fryx1 are long thin rods and contain gas vesicles, the first report of such structures in purple non-sulfur bacteria. gas vesicles are clustered at 2-4 sites per cell. surprisingly, the 16s rrna gene sequence of strain fryx1 is nearly identical to that of rfx. antarctic ... | 2004 | 15340780 |
| localization and characterization of two novel genes encoding stereospecific dioxygenases catalyzing 2(2,4-dichlorophenoxy)propionate cleavage in delftia acidovorans mc1. | two novel genes, rdpa and sdpa, encoding the enantiospecific alpha-ketoglutarate dependent dioxygenases catalyzing r,s-dichlorprop cleavage in delftia acidovorans mc1 were identified. significant similarities to other known genes were not detected, but their deduced amino acid sequences were similar to those of other alpha-ketoglutarate dioxygenases. rdpa showed 35% identity with taud of pseudomonas aeruginosa, and sdpa showed 37% identity with tfda of ralstonia eutropha jmp134. the functionally ... | 2004 | 15345421 |
| propylphenols are metabolites in the anaerobic biodegradation of propylbenzene under iron-reducing conditions. | the metabolism of monoaromatic hydrocarbons by an iron-reducing bacterial enrichment culture originating from diesel-contaminated groundwater was examined using d7-propylbenzene as a model hydrocarbon. sequence analysis of the 16s rdna gene showed that the dominant part (10 of 10 clones) of the enrichment culture consisted of a bacterium closely related to clones found in benzene-contaminated groundwater and to the iron-reducing beta-proteobacterium, rhodoferax ferrireducens (similarity values w ... | 2005 | 15865149 |
| molecular characterization of the nonphotosynthetic partner bacterium in the consortium "chlorochromatium aggregatum". | phototrophic consortia represent valuable model systems for the study of signal transduction and coevolution between different bacteria. the phototrophic consortium "chlorochromatium aggregatum" consists of a colorless central rod-shaped bacterium surrounded by about 20 green-pigmented epibionts. although the epibiont was identified as a member of the green sulfur bacteria, and recently isolated and characterized in pure culture, the central colorless bacterium has been identified as a member of ... | 2005 | 16269785 |
| bacterial diversity of metagenomic and pcr libraries from the delaware river. | to determine whether metagenomic libraries sample adequately the dominant bacteria in aquatic environments, we examined the phylogenetic make-up of a large insert metagenomic library constructed with bacterial dna from the delaware river, a polymerase chain reaction (pcr) library of 16s rrna genes, and community structure determined by fluorescence in situ hybridization (fish). the composition of the libraries and community structure determined by fish differed for the major bacterial groups in ... | 2005 | 16309387 |
| recurring seasonal dynamics of microbial communities in stream habitats. | recurring seasonal patterns of microbial distribution and abundance in three third-order temperate streams within the southeast pennsylvania piedmont were observed over 4 years. populations associated with streambed sediments and rocks (epilithon) were identified using terminal restriction length polymorphism (trflp) and sequencing of 16s rrna genes selectively amplified with primers for the bacterial domain. analyses of the relative magnitudes of trflp peak areas by using nonmetric multidimensi ... | 2006 | 16391111 |
| [construction of sugar-based microbial fuel cells by dissimilatory metal reduction bacteria]. | dissimilatory metal reduction bacteria play an important role in the anaerobic environment. this kind of bacteria gains energy by coupling the oxidation of organic acid or sugars to the reduction of metal oxides. the graphite electrode rode can also be used as the final electron acceptor due to its similarity to solid metal oxides. based on this biological mechanism, dissimilatory metal reduction bacteria rhodoferaxferrireducens was used to construct a suit of microbial fuel cells with sugars as ... | 2006 | 16572853 |
| 16s rdna-based analysis of dominant bacterial populations associated with early life stages of coho salmon (oncorhynchus kisutch). | in this study, we used a 16s rdna-based approach to determine bacterial populations associated with coho salmon (oncorhynchus kisutch) in its early life stages, highlighting dominant bacteria in the gastrointestinal tract during growth in freshwater. the present article is the first molecular analysis of bacterial communities of coho salmon. cultivability of the salmon gastrointestinal microbiota was estimated by comparison of direct microscopic counts (using acridine orange) with colony counts ... | 2006 | 16598631 |
| bacterial diversity within the planktonic community of an artesian water supply. | culture and molecular methods were used to describe the planktonic bacterial diversity of an artesian water supply in rural latah county, idaho, within the drainage of a small perennial stream, thorn creek. the surrounding depth to groundwater at this location is thought to be significant (>100 m), and this transitional zone (basalt-granite) of the palouse aquifer system is little studied. the water produced by this artesian source is consistent even in years of drought and is of high quality, b ... | 2006 | 16604121 |
| heterogeneous aerobic benzene-degrading communities in oxygen-depleted groundwaters. | a sandstone aquifer beneath a petrochemicals plant (siren site, uk) is heterogeneously contaminated with benzene and oxygen-depleted. despite low redox potentials in three of the most contaminated groundwaters (benzene concentrations from 17.8 to 294 mg l(-1)), we observed aerobic benzene degradation in microcosms, indicating the presence in situ of a latent community of obligate aerobic microorganisms or an active community of facultative aerobes responding rapidly to oxygen ingress. moreover, ... | 2006 | 17064267 |
| bacterial diversity in the active stage of a bioremediation system for mineral oil hydrocarbon-contaminated soils. | soils contaminated with mineral oil hydrocarbons are often cleaned in off-site bioremediation systems. in order to find out which bacteria are active during the degradation phase in such systems, the diversity of the active microflora in a degrading soil remediation system was investigated by small-subunit (ssu) rrna analysis. two sequential rna extracts from one soil sample were generated by a procedure incorporating bead beating. both extracts were analysed separately by generating individual ... | 2006 | 17074900 |
| improving energy accumulation of microbial fuel cells by metabolism regulation using rhodoferax ferrireducens as biocatalyst. | to study the physiology and metabolism of microbial cells in the performance of microbial fuel cells (mfcs). | 2007 | 17397477 |
| metabolic activity and phylogenetic diversity of reed (phragmites australis) periphyton bacterial communities in a hungarian shallow soda lake. | in the present study, the species composition and potential metabolic activities of bacterial communities of reed phragmites australis (cav.) (trin. ex steudel) periphyton from lake velencei were studied by cultivation-based and metabolic fingerprinting methods. serially diluted spring biofilm samples were used to test the community-level physiological profiling (clpp) using biolog microplates, and for plating onto different media. on the basis of their morphological, biochemical, and physiologi ... | 2007 | 17406774 |
| diversity and distribution of ecotypes of the aerobic anoxygenic phototrophy gene pufm in the delaware estuary. | the diversity of aerobic anoxygenic phototrophic (aap) bacteria has been examined in marine habitats, but the types of aap bacteria in estuarine waters and distribution of ecotypes in any environment are not well known. the goal of this study was to determine the diversity of aap bacteria in the delaware estuary and to examine the distribution of select ecotypes using quantitative pcr (qpcr) assays for the pufm gene, which encodes a protein in the light reaction center of aap bacteria. in pcr li ... | 2008 | 18469118 |
| microbiological monitoring of acid mine drainage treatment systems and aquatic surroundings using real-time pcr. | in general, acid mine drainage (amd) causes low ph and high metal concentrations in mining areas and surroundings. the aim of this research was to achieve microbiological monitoring for amd and to assess whether mine water outflows have any ecological effects on the aqueous ecosystem receiving effluents from different types of treatment system. the water quality of aquatic sample was analyzed and the molecular biological diversity of the samples was assessed using 16s rrna methods, which were im ... | 2009 | 19494446 |
| influence of heterogeneous ammonium availability on bacterial community structure and the expression of nitrogen fixation and ammonium transporter genes during in situ bioremediation of uranium-contaminated groundwater. | the influence of ammonium availability on bacterial community structure and the physiological status of geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. ammonium concentrations varied by 2 orders of magnitude (< 4 to 400 microm) across th study site. analysis of 16s rrna sequences suggested that ammonium may have been one factor influencing the community composition prior to acetate amendment with rhodoferax species predominating over geobacter s ... | 2009 | 19603651 |
| pseudorhodoferax soli gen. nov., sp. nov. and pseudorhodoferax caeni sp. nov., two members of the class betaproteobacteria belonging to the family comamonadaceae. | a novel betaproteobacterium, strain tbea3(t), was isolated from soil using enrichment cultures with the organic thioether 3,3'-thiodipropionic acid as sole carbon and energy source. analysis of the 16s rrna gene sequence revealed 99.1 % sequence similarities to a poorly characterized member of the family comamonadaceae, strain sb1(t), which had been previously isolated from activated sludge. both strains showed highest gene sequence similarities (up to 96.9 %) to members of the genera rhodoferax ... | 2009 | 19625429 |
| limnohabitans curvus gen. nov., sp. nov., a planktonic bacterium isolated from a freshwater lake. | a chemo-organotrophic, aerobic, facultatively anaerobic, non-motile strain, mwh-c5(t), isolated from the water column of the oligomesotrophic lake mondsee (austria), was characterized phenotypically, phylogenetically and chemotaxonomically. the predominant fatty acids of the strain were c(16 : 1)omega7c/omega6c, c(16 : 0), c(12 : 1) and c(8 : 0)-3oh, the major quinone was ubiquinone q-8 and the g+c content of the dna of the strain was 55.5 mol%. 16s rrna gene similarity to the closest related ty ... | 2010 | 19671731 |
| albidoferax, a new genus of comamonadaceae and reclassification of rhodoferax ferrireducens (finneran et al., 2003) as albidoferax ferrireducens comb. nov. | | 2009 | 19700925 |
| genome-scale comparison and constraint-based metabolic reconstruction of the facultative anaerobic fe(iii)-reducer rhodoferax ferrireducens. | rhodoferax ferrireducens is a metabolically versatile, fe(iii)-reducing, subsurface microorganism that is likely to play an important role in the carbon and metal cycles in the subsurface. it also has the unique ability to convert sugars to electricity, oxidizing the sugars to carbon dioxide with quantitative electron transfer to graphite electrodes in microbial fuel cells. in order to expand our limited knowledge about r. ferrireducens, the complete genome sequence of this organism was further ... | 2009 | 19772637 |
| the cytophaga hutchinsonii chtpsp: first characterized bifunctional tps-tpp protein as putative ancestor of all eukaryotic trehalose biosynthesis proteins. | the most widely distributed pathway to synthesize trehalose in nature consists of two consecutive enzymatic reactions with a trehalose-6-p (t6p)-synthase (tps) enzyme, producing the intermediate t6p, and a t6p-phosphatase (tpp) enzyme, which dephosphorylates t6p to produce trehalose and inorganic phosphate. in plants, these enzymes are called class i and class ii proteins, respectively, with some class i proteins being active enzymes. the class ii proteins possess both tps and tpp consensus regi ... | 2010 | 19812028 |
| application of electro-active biofilms. | the concept of an electro-active biofilm (eab) has recently emerged from a few studies that discovered that certain bacteria which form biofilms on conductive materials can achieve a direct electrochemical connection with the electrode surface using it as electron exchanger, without the aid of mediators. this electro-catalytic property of biofilms has been clearly related to the presence of some specific strains that are able to exchange electrons with solid substrata (eg geobacter sulfurreducen ... | 2010 | 20390557 |
| mature fine tailings from oil sands processing harbour diverse methanogenic communities. | processing oil sands to extract bitumen produces large volumes of a tailings slurry comprising water, silt, clays, unrecovered bitumen, and residual solvent used in the extraction process. tailings are deposited into large settling basins, where the solids settle by gravity to become denser mature fine tailings (mft). a substantial flux of methane, currently estimated at ~40 million l/day, is being emitted from the mildred lake settling basin. to better understand the biogenesis of this greenhou ... | 2010 | 20657616 |
| genome-scale dynamic modeling of the competition between rhodoferax and geobacter in anoxic subsurface environments. | the advent of rapid complete genome sequencing, and the potential to capture this information in genome-scale metabolic models, provide the possibility of comprehensively modeling microbial community interactions. for example, rhodoferax and geobacter species are acetate-oxidizing fe(iii)-reducers that compete in anoxic subsurface environments and this competition may have an influence on the in situ bioremediation of uranium-contaminated groundwater. therefore, genome-scale models of geobacter ... | 2011 | 20668487 |
| a lipase with broad temperature range from an alkaliphilic gamma-proteobacterium isolated in greenland. | a gamma-proteobacterium related to the genera alteromonadales and pseudomonadales, isolated from a cold and alkaline environment in greenland, has been shown to produce a lipase active between 5 degrees c and 80 degrees c, with optimal activity at 55 degrees c and ph 8. pcr-based screening of genomic dna from the isolated bacterium, followed by genome walking, resulted in two complete open reading frames, which were predicted to encode a lipase and its helper protein, a lipase foldase. the amino ... | 2010 | 20718291 |
| endophytic bacterial diversity in roots of typha angustifolia l. in the constructed beijing cuihu wetland (china). | we investigated the community structure of endophytic bacteria in narrowleaf cattail (typha angustifolia l.) roots growing in the beijing cuihu wetland, china, using the 16s rdna library technique. in total, 184 individual sequences were used to assess the diversity of endophytic bacteria. phylogenetic analysis revealed that 161 clones (87.5%) were affiliated with proteobacteria, other clones grouped into cytophaga/flexibacter/bacteroids (3.3%), fusobacteria (3.8%), and nearly 5% were uncultured ... | 2010 | 21111814 |
| abundance and community of snow bacteria from three glaciers in the tibetan plateau. | bacterial abundance and diversity in snow of east rongbuk, laohugou and hailuogou glaciers on the tibetan plateau were investigated through epifluorescence microscope and denaturing gradient gel electrophoresis. cell abundance ranged from 4.0 x 10(3) to 290.2 x 10(3) cells/ml. the phylogenetic trees placed the 16s rrna sequences in four major groups: proteobacteria, firmicutes, actinobacteria and bacteroidetes. brevundimonas, flavobacterium, hymenobacter, bacillus, polaromonas, rhodoferax and st ... | 2010 | 21174974 |
| identification of tertiary butyl alcohol (tba)-utilizing organisms in biogac reactors using 13c-dna stable isotope probing. | biodegradation of the gasoline oxygenates methyl tertiary-butyl ether (mtbe) and ethyl tertiary-butyl ether (etbe) can cause tertiary butyl alcohol (tba) to accumulate in gasoline-impacted environments. one remediation option for tba-contaminated groundwater involves oxygenated granulated activated carbon (gac) reactors that have been self-inoculated by indigenous tba-degrading microorganisms in ground water extracted from contaminated aquifers. identification of these organisms is important for ... | 2011 | 21286787 |
| geochemical and microbiological processes contributing to the transformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (rdx) in contaminated aquifer material. | hexahydro-1,3,5-trinitro-1,3,5-triazine (rdx) is a potential human carcinogen, and its contamination of subsurface environments is a significant threat to public health. this study investigated abiotic and biological degradation of rdx in contaminated aquifer material. anoxic batch systems were started with and without pre-aeration of aquifer material to distinguish initial biological rdx reduction from abiotic rdx reduction. aerating the sediment eliminated chemical reductants in the native aqu ... | 2011 | 21664641 |
| degradation of a benzene-toluene mixture by hydrocarbon-adapted bacterial communities. | we examined the rate of degradation of a benzene-toluene mixture in aerobic microcosms prepared with samples of an aquifer that lies below a petrochemical plant (siren, uk). five samples exposed to different concentrations of benzene (from 0.6 to 317 mg l(-1)) were used. fast degradation (approx. 1-6 mg l(-1) day(-1)) of both contaminants was observed in all groundwater samples and complete degradation was recorded by the seventh day except for one sample. we also identified the microbial commun ... | 2011 | 21949494 |
| evaluation of microbial biofilm communities from an alberta oil sands tailings pond. | bitumen extraction from the oil sands of alberta has resulted in millions of cubic meters of waste stored on-site in tailings ponds. unique microbial ecology is expected in these ponds, which may be key to their bioremediation potential. we considered that direct culturing of microbes from a tailings sample as biofilms could lead to the recovery of microbial communities that provide good representation of the ecology of the tailings. culturing of mixed species biofilms in vitro using the calgary ... | 2011 | 22029695 |
| Efficient electricity generation from sewage sludge usingbiocathode microbial fuel cell. | Microbial fuel cells (MFCs) with abiotic cathodes require expensive catalyst (such as Pt) or catholyte (such as hexacynoferrate) to facilitate oxidation reactions. This study incorporated biocathodes into a three-chamber MFC to yield electricity from sewage sludge at maximum power output of 13.2±1.7W/m(3) during polarization, much higher than those previously reported. After 15d operation, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of cell reached 40.8±9.0% and ... | 2012 | 22078254 |
| bacterial communities in an ultrapure water containing storage tank of a power plant. | ultrapure waters (upws) containing low levels of organic and inorganic compounds provide extreme environment. on contrary to that microbes occur in such waters and form biofilms on surfaces, thus may induce corrosion processes in many industrial applications. in our study, refined saltless water (upw) produced for the boiler of a hungarian power plant was examined before and after storage (sampling the inlet [tke] and outlet [tku] waters of a storage tank) with cultivation and culture independen ... | 2011 | 22207294 |
| quantification of subfamily i.2.c catechol 2,3-dioxygenase mrna transcripts in groundwater samples of an oxygen-limited btex-contaminated site. | low dissolved oxygen concentration of subsurface environments is a limiting factor for microbial aromatic hydrocarbon degradation, and to date, there are only a limited number of available reports on functional genes and microbes that take part in the degradation of aromatic hydrocarbons under hypoxic conditions. recent discoveries shed light on the prevalence of subfamily i.2.c catechol 2,3-dioxygenases in petroleum hydrocarbon contaminated hypoxic groundwaters, and their considerable environme ... | 2011 | 22091737 |
| rhodoferax-related pufm gene cluster dominates the aerobic anoxygenic phototrophic communities in german freshwater lakes. | the presence of aerobic anoxygenic phototrophs (aaps) has been repeatedly reported from various marine environments, but their distribution in freshwater lakes was neglected until recently. we investigated the phylogenetic composition of aap communities in 10 lakes in northeastern germany with different trophic status including oligotrophic lake stechlin and humic matter rich lake grosse fuchskuhle. the aap community was composed by members of alpha- and betaproteobacteria, but their contributio ... | 2011 | 21895915 |
| betaproteobacteria dominance and diversity shifts in the bacterial community of a pah-contaminated soil exposed to phenanthrene. | in this study, the pah-degrading bacteria of a constructed wetland collecting road runoff has been studied through dna stable isotope probing. microcosms were spiked with (13)c-phenanthrene at 34 or 337 ppm, and bacterial diversity was monitored over a 14-day period. at 337 ppm, pah degraders became dominated after 5 days by betaproteobacteria, including novel acidovorax, rhodoferax and hydrogenophaga members, and unknown bacteria related to rhodocyclaceae. the prevalence of betaproteobacteria w ... | 2012 | 22243884 |