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Sample records for hydrocarbon residues microbial

  1. Biodegradation pattern of hydrocarbons from a fuel oil-type complex residue by an emulsifier-producing microbial consortium.

    Science.gov (United States)

    Nievas, M L; Commendatore, M G; Esteves, J L; Bucalá, V

    2008-06-15

    The biodegradation of a hazardous waste (bilge waste), a fuel oil-type complex residue from normal ship operations, was studied in a batch bioreactor using a microbial consortium in seawater medium. Experiments with initial concentrations of 0.18 and 0.53% (v/v) of bilge waste were carried out. In order to study the biodegradation kinetics, the mass of n-alkanes, resolved hydrocarbons and unresolved complex mixture (UCM) hydrocarbons were assessed by gas chromatography (GC). Emulsification was detected in both experiments, possibly linked to the n-alkanes depletion, with differences in emulsification start times and extents according to the initial hydrocarbon concentration. Both facts influenced the hydrocarbon biodegradation kinetics. A sequential biodegradation of n-alkanes and UMC was found for the higher hydrocarbon content. Being the former growth associated, while UCM biodegradation was a non-growing process showing enzymatic-type biodegradation kinetics. For the lower hydrocarbon concentration, simultaneous biodegradation of n-alkanes and UMC were found before emulsification. Nevertheless, certain UCM biodegradation was observed after the medium emulsification. According to the observed kinetics, three main types of hydrocarbons (n-alkanes, biodegradable UCM and recalcitrant UCM) were found adequate to represent the multicomponent substrate (bilge waste) for future modelling of the biodegradation process.

  2. Microbial degradation of petroleum hydrocarbons.

    Science.gov (United States)

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Microbial production of gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hideo

    1987-10-20

    Microbial production of ethylene, isobutane and a saturated gaseous hydrocarbon mixture was described. Microbial ethylene production was studied with Penicillium digitatum IFO 9372 and a novel pathway of the ethylene biosynthesis through alpha-ketoglutarate was proposed. Rhodotorula minuta IFO 1102 was selected for the microbial production of isobutane and the interesting actions of L-leucine and L-phenylalanine for the isobutane production were found. It was finally presented about the microbial production of a saturated gaseous hydrocarbon mixture with Rhizopus japonicus IFO 4758 was described. A gas mixture was produced through a chemical reaction of SH compounds and some cellular component such as squalene under aerobic conditions. (4 figs, 7 tabs, 41 refs)

  4. Microbial biodegradation of polyaromatic hydrocarbons.

    Science.gov (United States)

    Peng, Ri-He; Xiong, Ai-Sheng; Xue, Yong; Fu, Xiao-Yan; Gao, Feng; Zhao, Wei; Tian, Yong-Sheng; Yao, Quan-Hong

    2008-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Because of their hydrophobic nature, most PAHs bind to particulates in soil and sediments, rendering them less available for biological uptake. Microbial degradation represents the major mechanism responsible for the ecological recovery of PAH-contaminated sites. The goal of this review is to provide an outline of the current knowledge of microbial PAH catabolism. In the past decade, the genetic regulation of the pathway involved in naphthalene degradation by different gram-negative and gram-positive bacteria was studied in great detail. Based on both genomic and proteomic data, a deeper understanding of some high-molecular-weight PAH degradation pathways in bacteria was provided. The ability of nonligninolytic and ligninolytic fungi to transform or metabolize PAH pollutants has received considerable attention, and the biochemical principles underlying the degradation of PAHs were examined. In addition, this review summarizes the information known about the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted ecosystems. A deeper understanding of the microorganism-mediated mechanisms of catalysis of PAHs will facilitate the development of new methods to enhance the bioremediation of PAH-contaminated sites.

  5. Thermal Adsorption Processing Of Hydrocarbon Residues

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    Sudad H. Al.

    2015-08-01

    Full Text Available The raw materials of secondary catalytic processes must be pre-refined. Among these refining processes are the deasphalting and demetallization including their thermo adsorption or thermo-contact adsorption variety. In oil processing four main processes of thermo-adsorption refining of hydrocarbon residues are used ART Asphalt Residual Treating - residues deasphaltizing 3D Discriminatory Destructive Distillation developed in the US ACT Adsorption-Contact Treatment and ETCC Express Thermo-Contact Cracking developed in Russia. ART and ACT are processes with absorbers of lift type reactor while 3D and ETCC processes are with an adsorbing reactor having ultra-short contact time of the raw material with the adsorbent. In all these processes refining of hydrocarbon residues is achieved by partial Thermo-destructive transformations of hydrocarbons and hetero-atomic compounds with simultaneous adsorption of the formed on the surface of the adsorbents resins asphaltene and carboids as well as metal- sulphur - and nitro-organic compounds. Demetallized and deasphalted light and heavy gas oils or their mixtures are a quality raw material for secondary deepening refining processes catalytic and hydrogenation cracking etc. since they are characterized by low coking ability and low content of organometallic compounds that lead to irreversible deactivation of the catalysts of these deepening processes.

  6. Plant residues--a low cost, effective bioremediation treatment for petrogenic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Shahsavari, Esmaeil; Adetutu, Eric M; Anderson, Peter A; Ball, Andrew S

    2013-01-15

    Petrogenic hydrocarbons represent the most commonly reported environmental contaminant in industrialised countries. In terms of remediating petrogenic contaminated hydrocarbons, finding sustainable non-invasive technologies represents an important goal. In this study, the effect of 4 types of plant residues on the bioremediation of aliphatic hydrocarbons was investigated in a 90 day greenhouse experiment. The results showed that contaminated soil amended with different plant residues led to statistically significant increases in the utilisation rate of Total Petroleum Hydrocarbon (TPH) relative to control values. The maximum TPH reduction (up to 83% or 6800 mg kg(-1)) occurred in soil mixed with pea straw, compared to a TPH reduction of 57% (4633 mg kg(-1)) in control soil. A positive correlation (0.75) between TPH reduction rate and the population of hydrocarbon-utilising microorganisms was observed; a weaker correlation (0.68) was seen between TPH degradation and bacterial population, confirming that adding plant materials significantly enhanced both hydrocarbonoclastic and general microbial soil activities. Microbial community analysis using Denaturing Gradient Gel Electrophoresis (DGGE) showed that amending the contaminated soil with plant residues (e.g., pea straw) caused changes in the soil microbial structure, as observed using the Shannon diversity index; the diversity index increased in amended treatments, suggesting that microorganisms present on the dead biomass may become important members of the microbial community. In terms of specific hydrocarbonoclastic activity, the number of alkB gene copies in the soil microbial community increased about 300-fold when plant residues were added to contaminated soil. This study has shown that plant residues stimulate TPH degradation in contaminated soil through stimulation and perhaps addition to the pool of hydrocarbon-utilising microorganisms, resulting in a changed microbial structure and increased alkB gene

  7. Bioremediation of petroleum hydrocarbons: catabolic genes, microbial communities, and applications.

    Science.gov (United States)

    Fuentes, Sebastián; Méndez, Valentina; Aguila, Patricia; Seeger, Michael

    2014-06-01

    Bioremediation is an environmental sustainable and cost-effective technology for the cleanup of hydrocarbon-polluted soils and coasts. In spite of that longer times are usually required compared with physicochemical strategies, complete degradation of the pollutant can be achieved, and no further confinement of polluted matrix is needed. Microbial aerobic degradation is achieved by the incorporation of molecular oxygen into the inert hydrocarbon molecule and funneling intermediates into central catabolic pathways. Several families of alkane monooxygenases and ring hydroxylating dioxygenases are distributed mainly among Proteobacteria, Actinobacteria, Firmicutes and Fungi strains. Catabolic routes, regulatory networks, and tolerance/resistance mechanisms have been characterized in model hydrocarbon-degrading bacteria to understand and optimize their metabolic capabilities, providing the basis to enhance microbial fitness in order to improve hydrocarbon removal. However, microbial communities taken as a whole play a key role in hydrocarbon pollution events. Microbial community dynamics during biodegradation is crucial for understanding how they respond and adapt to pollution and remediation. Several strategies have been applied worldwide for the recovery of sites contaminated with persistent organic pollutants, such as polycyclic aromatic hydrocarbons and petroleum derivatives. Common strategies include controlling environmental variables (e.g., oxygen availability, hydrocarbon solubility, nutrient balance) and managing hydrocarbon-degrading microorganisms, in order to overcome the rate-limiting factors that slow down hydrocarbon biodegradation.

  8. A modified microbial adhesion to hydrocarbons assay to account for the presence of hydrocarbon droplets.

    Science.gov (United States)

    Zoueki, Caroline Warne; Tufenkji, Nathalie; Ghoshal, Subhasis

    2010-04-15

    The microbial adhesion to hydrocarbons (MATH) assay has been used widely to characterize microbial cell hydrophobicity and/or the extent of cell adhesion to hydrophobic liquids. The classical MATH assay involves spectrophotometric absorbance measurements of the initial and final cell concentrations in an aqueous cell suspension that has been contacted with a hydrocarbon liquid. In this study, microscopic examination of the aqueous cell suspension after contact with hexadecane or a hexadecane/toluene mixture revealed the presence of hydrocarbon droplets. The hydrocarbon droplets contributed to the absorbance values during spectrophotometric measurements and caused erroneous estimates of cell concentrations and extents of microbial adhesion. A modified MATH assay that avoids such artefacts is proposed here. In this modified assay, microscopic examination of the aqueous suspension and direct cell counts provides cell concentrations that are free of interference from hydrocarbon droplets. The presence of hydrocarbon droplets was noted in MATH assays performed with three bacterial strains, and two different hydrocarbons, at ionic strengths of 0.2 mM and 20 mM and pH 6. In these experiments, the formation of quasi-stable hydrocarbon droplets cannot be attributed to the presence of biosurfactants, or stabilization by biocolloids. The presence of surface potential at the hydrocarbon-water interface that was characterized by electrophoretic mobility of up to -1 and -2 microm cm/Vs, likely caused the formation of the quasi-stable hydrocarbon droplets that provided erroneous results using the classical MATH assay.

  9. Microbial Hydrocarbon and ToxicPollutant Degradation Method

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Dietrich [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Janabi, Mustafa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); O' Neil, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Budinger, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-08-16

    The goal of this project is to determine optimum conditions for bacterial oxidation of hydrocarbons and long-chain alkanes that are representative of petroleum contamination of the environment. Polycyclic Aromatic Hydrocarbons (PAHs) are of concern because of their toxicity, low volatility, and resistance to microbial degradation, especially under anaerobic conditions. The uniqueness of our approach is to use carbon-11 in lieu of the traditional use of carbon-14.

  10. MICROBIAL CELL-SURFACE HYDROPHOBICITY - THE INVOLVEMENT OF ELECTROSTATIC INTERACTIONS IN MICROBIAL ADHESION TO HYDROCARBONS (MATH)

    NARCIS (Netherlands)

    GEERTSEMADOORNBUSCH, GI; VANDERMEI, HC; BUSSCHER, HJ

    Microbial adhesion to hydrocarbons (MATH) is the most commonly used method to determine microbial cell surface hydrophobicity. Since, however, the assay is based on adhesion, it is questionable whether the results reflect only the cell surface hydrophobicity or an interplay of hydrophobicity and

  11. Microbial degradation of petroleum hydrocarbons in soil

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    Kupka Daniel

    1997-09-01

    Full Text Available The abilities of microorganisms to mineralize a wide range of pollutants are well known. Biological processes for the removal of crude oil hydrocarbons from environment are attractive because they consume less energy than conventional physico-chemical processes and offer possibilities for recycling chemicals in the framework of integrated system.

  12. Initial microbial degradation of polycyclic aromatic hydrocarbons

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    Milić Jelena

    2016-01-01

    Full Text Available The group of polycyclic aromatic hydrocarbons (PAHs are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas. [Projekat Ministarstva nauke Republike Srbije, br. III43004

  13. Microbial hydrocarbons: back to the future

    Energy Technology Data Exchange (ETDEWEB)

    Work, Victoria H.; Beliaev, Alex S.; Konopka, Allan; Posewitz, Matthew C.

    2012-03-01

    The defining challenge of energy research in the 21st century is the development and deployment of technologies for large-scale reconfiguration of global energy infrastructure. Modern society is built upon a concentrated yet finite reservoir of diverse hydrocarbons formed through the photosynthetic transformation of several hundred million years of solar energy. In human history, the fossil energy era will be short lived and never repeated. Although the timing of peak oil is extensively debated, it is an eventuality. It is, therefore, imperative that projections for both when it will occur and the degree to which supply will fall short of demand be taken into serious consideration, especially in the sectors of energy technology development, political and economic decision making, and societal energy usage. The requirement for renewable energy systems is no longer a point for discussion, and swift advances on many fronts are vital to counteract current and impending crises in both energy and the environment.

  14. Impact of diverse soil microbial communities on crop residues decomposition

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    Mrad, Fida; Bennegadi-Laurent, Nadia; Ailhas, Jérôme; Leblanc, Nathalie; Trinsoutrot-Gattin, Isabelle; Laval, Karine; Gattin, Richard

    2017-04-01

    Soils provide many basic ecosystem services for our society and most of these services are carried out by the soil communities, thus influencing soils quality. Soil organic matter (SOM) can be considered as one of the most important soil quality indices for it plays a determinant role in many physical, chemical and biological processes, such as soil structure and erosion resistance, cation exchange capacity, nutrient cycling and biological activity (Andrews et al., 2004). Since a long time, exogenous organic inputs are largely used for improving agricultural soils, affecting highly soil fertility and productivity. The use of organic amendments such as crop residues influences the soil microbial populations' diversity and abundance. In the meantime, soil microbial communities play a major role in the organic matter degradation, and the effect of different microbial communities on the decomposition of crop residues is not well documented. In this context, studying the impact of crop residues on soil microbial ecology and the processes controlling the fate of plant residues in different management practices is essential for understanding the long-term environmental and agronomic effects on soil and organic matters. Our purpose in the present work was to investigate the decomposition by two contrasting microbial communities of three crop residues, and compare the effect of different residues amendments on the abundance and function of each soil microbial communities. Among the main crops which produce large amounts of residues, we focused on three different plants: wheat (Triticum aestivum L.), rape (Brassica napus) and sunflower (Helianthus annuus). The residues degradation in two soils of different management practices and the microbial activity were evaluated by: microbial abundance (microbial carbon, culturable bacteria, total DNA, qPCR), in combination with functional indicators (enzymatic assays and Biolog substrate utilization), kinetics of C and N

  15. 40 CFR 180.526 - Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons; tolerances for residues. 180.526 Section 180.526 Protection of Environment ENVIRONMENTAL... FOOD Specific Tolerances § 180.526 Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues. (a) General. Synthetic isoparaffinic petroleum hydrocarbons complying with 21 CFR 172.882 (a)...

  16. A water and hydrocarbon emulsion for extracting residual oil

    Energy Technology Data Exchange (ETDEWEB)

    Verderevskiy, Yu.L.; Abramzon, A.A.; Gusev, V.I.; Kulikov, Yu.M.; Petrov, A.G.; Starosud, A.N.; Tavrin, A.Ye.; Zheranin, V.L.

    1984-01-01

    The purpose of the invention is to improve the oil displacing properties of the composition in conditions of high mineralization of the stratum waters and to reduce the cost of the emulsion. To do this, the water and hydrocarbon emulsion for extracting residual oil, which includes water, liquid hydrocarbons, water and oil soluble surfacants (PAV), contains oxyethylated alkylphenol of the OP-10 type as the water soluble surfacant and contains oxytehylated alkylphenol of the OP-4 type as the oil soluble surfacant in the following component relationship (percent by mass): oxyethylated alkylphenol of the OP-4 type, 3.9 to 5.5; oxyethylated alkylphenol of the OP-10 type, 0.1 to 0.2; liquid hydrocargon, 40 to 41 and water, the remainder.

  17. Microbial degradation of petrochemical waste-polycyclic aromatic hydrocarbons.

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    Fulekar, M H

    2017-01-01

    Petrochemical industry is one of the fastest growing industries. This industry has immense importance in the growth of economy and manufacture of large varieties of chemicals. The petrochemical industry is a hazardous group of industry generating hazardous waste containing organic and inorganic compounds. In spite of the present treatment process, the hazardous waste compounds are found untreated to the acceptable level and found discharged at soil-water environment resulting into the persistent organic-inorganic pollutant into the environment. The bioremediation will be the innovative techniques to remove the persistent pollutants in the environment. Petrochemical contaminated site was found to be a rich source of microbial consortium degrading polycyclic aromatic hydrocarbons. Indigenous microbial consortiums were identified and used for bioremediation of polycyclic aromatic hydrocarbons (naphthalene and anthracene) at the concentrations of 250, 500, and 750 ppm. The potential microorganism was also identified for naphthalene and anthracene, and their bioremediation was studied at varying concentrations. The bioremediation with consortium was found to be comparatively more effective than the potential microorganism used for bioremediation of each compound. Pseudomonas aeruginosa a potential organism was identified by 16S rRNA and further studied for the gene responsible for the PAH compounds. Indigenous microorganism as a consortium has been found effective and efficient source for remediation of organic compound-Polycyclic aromatic hydrocarbon and this will also be applicable to remediate the toxic compounds to clean up the environment.

  18. Microbial contamination of stored hydrocarbon fuels and its control

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    Gaylarde Christine C.

    1999-01-01

    Full Text Available The major microbial problem in the petroleum refining industry is contamination of stored products, which can lead to loss of product quality, formation of sludge and deterioration of pipework and storage tanks, both in the refinery and at the end-user. Three major classes of fuel are discussed in this article - gasoline, aviation kerosene and diesel, corresponding to increasingly heavy petroleum fractions. The fuel that presents the most serious microbiological problems is diesel. The many microorganisms that have been isolated from hydrocarbon fuel systems are listed. The conditions required for microbial growth and the methods used to monitor and to control this activity are discussed. The effects of various fuel additives, including biocides, are considered.

  19. Enhanced biodegradation of hydrocarbons in soil by microbial biosurfactant, sophorolipid.

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    Kang, Seok-Whan; Kim, Young-Bum; Shin, Jae-Dong; Kim, Eun-Ki

    2010-03-01

    Effectiveness of a microbial biosurfactant, sophorolipid, was evaluated in washing and biodegradation of model hydrocarbons and crude oil in soil. Thirty percent of 2-methylnaphthalene was effectively washed and solubilized with 10 g/L of sophorolipid with similar or higher efficiency than that of commercial surfactants. Addition of sophorolipid in soil increased biodegradation of model compounds: 2-methylnaphthalene (95% degradation in 2 days), hexadecane (97%, 6 days), and pristane (85%, 6 days). Also, effective biodegradation method of crude oil in soil was observed by the addition of sophorolipid, resulting in 80% biodegradation of saturates and 72% aromatics in 8 weeks. These results showed the potentials of the microbial biosurfactant, sophorolipid, as an effective surfactant for soil washing and as an in situ biodegradation enhancer.

  20. Interpreting Interactions between Ozone and Residual Petroleum Hydrocarbons in Soil.

    Science.gov (United States)

    Chen, Tengfei; Delgado, Anca G; Yavuz, Burcu M; Maldonado, Juan; Zuo, Yi; Kamath, Roopa; Westerhoff, Paul; Krajmalnik-Brown, Rosa; Rittmann, Bruce E

    2017-01-03

    We evaluated how gas-phase O3 interacts with residual petroleum hydrocarbons in soil. Total petroleum hydrocarbons (TPH) were 18 ± 0.6 g/kg soil, and TPH carbon constituted ∼40% of the dichloromethane-extractable carbon (DeOC) in the soil. At the benchmark dose of 3.4 kg O3/kg initial TPH, TPH carbon was reduced by nearly 6 gC/kg soil (40%), which was accompanied by an increase of about 4 gC/kg soil in dissolved organic carbon (DOC) and a 4-fold increase in 5-day biochemical oxygen demand (BOD5). Disrupting gas channeling in the soil improved mass transport of O3 to TPH bound to soil and increased TPH removal. Ozonation resulted in two measurable alterations of the composition of the organic carbon. First, part of DeOC was converted to DOC (∼4.1 gC/kg soil), 75% of which was not extractable by dichloromethane. Second, the DeOC containing saturates, aromatics, resins, and asphaltenes (SARA), was partially oxidized, resulting in a decline in saturates and aromatics, but increases in resins and asphaltenes. Ozone attack on resins, asphaltenes, and soil organic matter led to the production of NO3(-), SO4(2-), and PO4(3-). The results illuminate the mechanisms by which ozone gas interacted with the weathered petroleum residuals in soil to generate soluble and biodegradable products.

  1. Microbial Bioremediation of Fuel Oil Hydrocarbons in Marine Environment

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    Sapna Pavitran

    2006-04-01

    Full Text Available Pollution in marine environment due to heavier petroleum products such as high-speeddiesel is known to take from days to months for complete natural remediation owing to its lowvolatility. For the survival of marine flora and fauna, it is important to control pollution causedby such recalcitrant and xenobiotic substances. Several petroleum hydrocarbons found in natureare toxic and recalcitrant. Therefore, pollution due to high-speed diesel is a cause of concern.The natural dispersion of high-speed diesel, a slow process, is attributed to an overall combinedeffect of physico-chemical and biological processes which take months for complete dispersion.History of marine oil spill bioremediation indicates limited laboratory studies. But experiencesfrom various oil spill management and field trials indicate important role of bioremediation, where,biodegradation of hydrocarbons through microbial mediators plays a major role in pollutant oildispersion. These microbial mediators such as bioemulsifiers and fimbrae, help in emulsification,dispersion, allowing attachment of bacteria to oil layers, followed by substrate-specific enzymaticbiodegradation in water.

  2. Microbial metabolism and community structure in response to bioelectrochemically enhanced remediation of petroleum hydrocarbon-contaminated soil.

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    Lu, Lu; Huggins, Tyler; Jin, Song; Zuo, Yi; Ren, Zhiyong Jason

    2014-04-01

    This study demonstrates that electrodes in a bioelectrochemical system (BES) can potentially serve as a nonexhaustible electron acceptor for in situ bioremediation of hydrocarbon contaminated soil. The deployment of BES not only eliminates aeration or supplement of electron acceptors as in contemporary bioremediation but also significantly shortens the remediation period and produces sustainable electricity. More interestingly, the study reveals that microbial metabolism and community structure distinctively respond to the bioelectrochemically enhanced remediation. Tubular BESs with carbon cloth anode (CCA) or biochar anode (BCA) were inserted into raw water saturated soils containing petroleum hydrocarbons for enhancing in situ remediation. Results show that total petroleum hydrocarbon (TPH) removal rate almost doubled in soils close to the anode (63.5-78.7%) than that in the open circuit positive controls (37.6-43.4%) during a period of 64 days. The maximum current density from the BESs ranged from 73 to 86 mA/m(2). Comprehensive microbial and chemical characterizations and statistical analyses show that the residual TPH has a strongly positive correlation with hydrocarbon-degrading microorganisms (HDM) numbers, dehydrogenase activity, and lipase activity and a negative correlation with soil pH, conductivity, and catalase activity. Distinctive microbial communities were identified at the anode, in soil with electrodes, and soil without electrodes. Uncommon electrochemically active bacteria capable of hydrocarbon degradation such as Comamonas testosteroni, Pseudomonas putida, and Ochrobactrum anthropi were selectively enriched on the anode, while hydrocarbon oxidizing bacteria were dominant in soil samples. Results from genus or phylum level characterizations well agree with the data from cluster analysis. Data from this study suggests that a unique constitution of microbial communities may play a key role in BES enhancement of petroleum hydrocarbons

  3. Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues.

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    Breedveld, Gijs D; Pelletier, Emilien; St Louis, Richard; Cornelissen, Gerard

    2007-04-01

    High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinitesink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (-100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples.

  4. IMPLICATIONS OF MICROBIAL ADHESION TO HYDROCARBONS FOR EVALUATING CELL-SURFACE HYDROPHOBICITY .1. ZETA-POTENTIALS OF HYDROCARBON DROPLETS

    NARCIS (Netherlands)

    BUSSCHER, HJ; VANDEBELTGRITTER, B; VANDERMEI, HC

    1995-01-01

    Microbial adhesion to hydrocarbons (MATH) is generally considered to be a measure of the organisms cell surface hydrophobicity. As microbial adhesion is a complicated interplay of long-range van der Waals and electrostatic forces and various short-range interactions, the above statement only holds

  5. Sediment biogeochemistry and microbial activity at natural hydrocarbon seeps and at sites impacted by anthropogenic hydrocarbon discharges

    Science.gov (United States)

    Joye, S. B.; Sibert, R.; Battles, J.; Fields, L.; Kleindienst, S.; Crespo-Medina, M.; Hunter, K.; Meile, C. D.; Montoya, J. P.

    2013-12-01

    Natural hydrocarbon seeps occur along the seafloor where geologic faults facilitate transfer of deeply sourced fluids enriched in gas, oil, and dissolved organic matter through shallow sediments and into the water column. At natural seeps, microbial populations specialize in hydrocarbon degradation and rates of microbial activity, including sulfate reduction and anaerobic oxidation of methane, can be extremely high. As a result, the biogeochemical signature of sediments near areas of active natural seepage is distinct: high concentrations of metabolic end products, such as dissolved inorganic carbon and hydrogen sulfide, abound, and often, high dissolved inorganic carbon concentrations result in the precipitation of authigenic carbonate minerals. We examined microbial processes and biogeochemical signatures at two natural seeps, Green Canyon 600 and Mississippi Canyon 118. Higher and more frequent seepage loci at the Green Canyon 600 site led to more widespread hotspots of elevated microbial activity and distinct geochemistry. However, rates of microbial activity were comparable at the two sites in areas of active hydrocarbon seepage. The microbial communities at the two sites were surprisingly different. The second group of sites was impacted by anthropogenic hydrocarbon discharges instead of natural seepage. One site, Oceanus 26, lies near the Deepwater Horizon/Macondo wellhead and was impacted by weathered oil sedimentation during the Macondo discharge. The second set of impacted sites, noted as Taylor Energy, lie near a sunken platform and compromised riser, which have together resulted in persistent hydrocarbon discharge to the adjacent oceanic system for more than 6 years. Rates of microbial activity in the upper sediments at Oceanus 26 were depressed relative to activity in the deeper layers, suggesting inhibition by the presence of weathered oil or an microbial community unable to weather the carbon available in the layer. At the Taylor energy site

  6. In situ microbial metabolism of aromatic-hydrocarbon environmental pollutants.

    Science.gov (United States)

    Jeon, Che Ok; Madsen, Eugene L

    2013-06-01

    Microbial processes that eliminate organic environmental contamination are important. Progress in the biotechnology of biodegradation relies upon the underlying sciences of environmental microbiology and analytical geochemistry. Recent key discoveries advancing knowledge of biodegradation (in general) and the aromatic-hydrocarbon biodegradation (in particular) have relied upon characterization of microorganisms: pure-culture isolates, laboratory enrichment cultures, and in contaminated field sites. New analytical and molecular tools (ranging from sequencing the DNA of biodegrading microorganisms to assessing changes in the isotopic ratios of 13C to 12C and 2H to 1H in contaminant pools in field sites) have deepened our insights into the mechanisms (how), the occurrence (what), and the identity (who) of active players that effect biodegradation of organic environmental pollutants.

  7. Limitations of microbial hydrocarbon degradation at the Amon mud volcano (Nile deep-sea fan

    Directory of Open Access Journals (Sweden)

    J. Felden

    2013-05-01

    Full Text Available The Amon mud volcano (MV, located at 1250 m water depth on the Nile deep-sea fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulfate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition, and microbial activities over 3 yr, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulfide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. The low microbial activity in the hydrocarbon-vented areas of Amon MV is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer MV area is limited by hydrocarbon transport.

  8. Response of the microbial community to seasonal groundwater level fluctuations in petroleum hydrocarbon-contaminated groundwater.

    Science.gov (United States)

    Zhou, Ai-xia; Zhang, Yu-ling; Dong, Tian-zi; Lin, Xue-yu; Su, Xiao-si

    2015-07-01

    The effects of seasonal groundwater level fluctuations on the contamination characteristics of total petroleum hydrocarbons (TPH) in soils, groundwater, and the microbial community were investigated at a typical petrochemical site in northern China. The measurements of groundwater and soil at different depths showed that significant TPH residue was present in the soil in this study area, especially in the vicinity of the pollution source, where TPH concentrations were up to 2600 mg kg(-1). The TPH concentration in the groundwater fluctuated seasonally, and the maximum variation was 0.8 mg L(-1). The highest TPH concentrations were detected in the silty clay layer and lied in the groundwater level fluctuation zones. The groundwater could reach previously contaminated areas in the soil, leading to higher groundwater TPH concentrations as TPH leaches into the groundwater. The coincident variation of the electron acceptors and TPH concentration with groundwater-table fluctuations affected the microbial communities in groundwater. The microbial community structure was significantly different between the wet and dry seasons. The canonical correspondence analysis (CCA) results showed that in the wet season, TPH, NO3(-), Fe(2+), TMn, S(2-), and HCO3(-) were the major factors correlating the microbial community. A significant increase in abundance of operational taxonomic unit J1 (97% similar to Dechloromonas aromatica sp.) was also observed in wet season conditions, indicating an intense denitrifying activity in the wet season environment. In the dry season, due to weak groundwater level fluctuations and low temperature of groundwater, the microbial activity was weak. But iron and sulfate-reducing were also detected in dry season at this site. As a whole, groundwater-table fluctuations would affect the distribution, transport, and biodegradation of the contaminants. These results may be valuable for the control and remediation of soil and groundwater pollution at this site

  9. Association of microbial community composition and activity with lead, chromium, and hydrocarbon contamination.

    Science.gov (United States)

    Shi, W; Becker, J; Bischoff, M; Turco, R F; Konopka, A E

    2002-08-01

    Microbial community composition and activity were characterized in soil contaminated with lead (Pb), chromium (Cr), and hydrocarbons. Contaminant levels were very heterogeneous and ranged from 50 to 16,700 mg of total petroleum hydrocarbons (TPH) kg of soil(-1), 3 to 3,300 mg of total Cr kg of soil(-1), and 1 to 17,100 mg of Pb kg of soil(-1). Microbial community compositions were estimated from the patterns of phospholipid fatty acids (PLFA); these were considerably different among the 14 soil samples. Statistical analyses suggested that the variation in PLFA was more correlated with soil hydrocarbons than with the levels of Cr and Pb. The metal sensitivity of the microbial community was determined by extracting bacteria from soil and measuring [(3)H]leucine incorporation as a function of metal concentration. Six soil samples collected in the spring of 1999 had IC(50) values (the heavy metal concentrations giving 50% reduction of microbial activity) of approximately 2.5 mM for CrO(4)2- and 0.01 mM for Pb2+. Much higher levels of Pb were required to inhibit [14C]glucose mineralization directly in soils. In microcosm experiments with these samples, microbial biomass and the ratio of microbial biomass to soil organic C were not correlated with the concentrations of hydrocarbons and heavy metals. However, microbial C respiration in samples with a higher level of hydrocarbons differed from the other soils no matter whether complex organic C (alfalfa) was added or not. The ratios of microbial C respiration to microbial biomass differed significantly among the soil samples (P < 0.05) and were relatively high in soils contaminated with hydrocarbons or heavy metals. Our results suggest that the soil microbial community was predominantly affected by hydrocarbons.

  10. Limitations of microbial hydrocarbon degradation at the Amon mud volcano (Nile deep-sea fan)

    NARCIS (Netherlands)

    Felden, J.; Lichtschlag, A.; Wenzhöfer, F.; de Beer, D.; Feseker, T.; Pop Ristova, P.; de Lange, G.; Boetius, A.

    2013-01-01

    The Amon mud volcano (MV), located at 1250m water depth on the Nile deep-sea fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amo

  11. IMPLICATIONS OF MICROBIAL ADHESION TO HYDROCARBONS FOR EVALUATING CELL-SURFACE HYDROPHOBICITY .2. ADHESION MECHANISMS

    NARCIS (Netherlands)

    VANDERMEI, HC; VANDEBELTGRITTER, B; BUSSCHER, HJ

    1995-01-01

    Microbial adhesion to hydrocarbons (MATH) is generally considered to be a measure of the organisms cell surface hydrophobicity. Recent observations that the zeta potentials of hydrocarbons can be highly negative in the various solutions commonly used in MATH, have suggested that MATH may measure a

  12. Enhanced dissipation of polycyclic aromatic hydrocarbons in the presence of fresh plant residues and their extracts.

    Science.gov (United States)

    Chen, Baoliang; Yuan, Miaoxin

    2012-02-01

    The feasibility of using fresh plant residues and their extracts to stimulate the bio-dissipation of polycyclic aromatic hydrocarbons (PAHs) were highlighted. Wood chip, bamboo leave, orange peel and their water-extractable organic matter (WEOM) were chosen as amendment materials. Effect of WEOM on bio-dissipation (bioaccumulation and biodegradation) of phenanthrene and pyrene from water by two bacteria were investigated. Orange peel extract demonstrated the highest efficiency for stimulating PAHs removal by bacterium B1 (Pseudomonas putida), while bamboo leave extract was the best one to enhance PAHs bio-dissipation by bacterium B2 (unidentified bacterium isolated from PAHs-contaminated soil). Amended the actual contaminated soil with 1% plant residues, PAHs dissipation were increased by 15-20%, 20-39%, 14-24%, 12-23% and 17-26%, respectively, for 2-, 3-, 4-, 5- and 6-ring PAHs via stimulating indigenous microbial degradation activity. Bamboo leave exhibited the most effective one to stimulate dissipation of PAHs in contaminated soil. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. 40 CFR 158.2130 - Microbial pesticides residue data requirements table.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Microbial pesticides residue data... (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2130 Microbial pesticides residue data requirements table. (a) General. Sections 158.100 through 158.130 describe how to...

  14. Microbial changes in rhizospheric soils contaminated with petroleum hydrocarbons after bioremediation

    Institute of Scientific and Technical Information of China (English)

    LIN Xin; LI Pei-jun; ZHOU Qi-xing; XU Hua-xia; ZHANG Hai-rong

    2004-01-01

    Effects of bioremediation on microbial communities in soils contaminated with petroleum hydrocarbons are a scientific problem to be solved. Changes in dominate microbial species and the total amount of microorganisms including bacteria and fungi in rhizospheric soils after bioremediation were thus evaluated using field bioremediation experiments. The results showed that there were changed dominant microorganisms including 11 bacterial strains which are mostly Gram positive bacteria and 6 fungal species which were identified. The total amount of microorganisms including bacteria and fungi increased after bioremediation of microbial agents combined with planting maize. On the contrary, fungi in rhizospheric soils were inhibited by adding microbial agents combined with planting soybean.

  15. Microbial degradation of crude oil hydrocarbons on organoclay minerals.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Manning, David A C; Fialips, Claire I

    2014-11-01

    The role of organoclays in hydrocarbon removal during biodegradation was investigated in aqueous clay/oil microcosm experiments with a hydrocarbon degrading microorganism community. The clays used for this study were Na-montmorillonite and saponite. These two clays were treated with didecyldimethylammonium bromide to produce organoclays which were used in this study. The study indicated that clays with high cation exchange capacity (CEC) such as Na-montmorillonite produced an organomontmorillonite that was inhibitory to biodegradation of the crude oil hydrocarbons. Extensive hydrophobic interaction between the organic phase of the organoclay and the crude oil hydrocarbons is suggested to render the hydrocarbons unavailable for biodegradation. However, untreated Na-montmorillonite was stimulatory to biodegradation of the hydrocarbons and is believed to have done so because of its high surface area for the accumulation of microbes and nutrients making it easy for the microbes to access the nutrients. This study indicates that unlike unmodified montmorillonites, organomontmorillonite may not serve any useful purpose in the bioremediation of crude oil spill sites where hydrocarbon removal by biodegradation is desired within a rapid time period.

  16. Measurement of Microbially Induced Transformation of Magnetic Iron Minerals in Soils Allows Localization of Hydrocarbon Contamination

    Science.gov (United States)

    Kappler, A.; Porsch, K.; Rijal, M.; Appel, E.

    2007-12-01

    Soil contamination by crude oil and other hydrocarbons represents a severe environmental problem, but often the location and extent of contamination is not known. Hydrocarbons, or their degradation products, can stimulate iron-metabolizing microorganisms, leading to the formation or dissolution of (magnetic) iron minerals and an associated change of soil magnetic properties. Therefore, the screening of soil magnetic properties has the potential to serve as an efficient and inexpensive tool to localize such contaminations. In order to identify the influence of different biogeochemical factors on the microbially influenced changes of magnetic iron minerals after hydrocarbon contamination, oil spills were simulated in laboratory batch experiments. The parameters tested in these experiments included soils with different bedrocks, type and amount of added hydrocarbon, and microbiological parameters (sterile and autochthonous microorganisms). In order to follow the changes of the soil magnetic properties, the magnetic susceptibility of the samples was measured weekly. First results show that changes in the magnetic mineralogy are caused by microbial activity, as sterile samples showed no changes. In the microbially active set-ups, the magnetic susceptibility increased or decreased up to 10% in comparison to the initial magnetic susceptibility within a few weeks. In one iron-rich soil even a decrease of the magnetic susceptibility of ~40% was observed. Although the amount and type of hydrocarbons did not effect the changes in magnetic susceptibility, DGGE fingerprints revealed that they influenced microbial communities. These results show that the magnetic susceptibility changes in the presence of hydrocarbons and that this change is microbially induced. This suggests that the screening of soil magnetic properties can be applied to localize and assess hydrocarbon contamination. In order to understand the biogeochemical processes better, the change of the iron mineralogy

  17. Soil microbial communities: Influence of geographic location and hydrocarbon pollutants

    CSIR Research Space (South Africa)

    Maila, MP

    2006-02-01

    Full Text Available (CLPP) and Polymerase Chain Reaction–Denaturing Gradient Gel Electrophoresis (PCR-DGGE). Hydrocarbon contaminated and uncontaminated soils from different geographical locations were used in the study. In addition, the influence or relevance...

  18. Association of Microbial Community Composition and Activity with Lead, Chromium, and Hydrocarbon Contamination

    OpenAIRE

    Shi, W.; Becker, J; Bischoff, M.; Turco, R. F.; Konopka, A. E

    2002-01-01

    Microbial community composition and activity were characterized in soil contaminated with lead (Pb), chromium (Cr), and hydrocarbons. Contaminant levels were very heterogeneous and ranged from 50 to 16,700 mg of total petroleum hydrocarbons (TPH) kg of soil−1, 3 to 3,300 mg of total Cr kg of soil−1, and 1 to 17,100 mg of Pb kg of soil−1. Microbial community compositions were estimated from the patterns of phospholipid fatty acids (PLFA); these were considerably different among the 14 soil sam...

  19. [Effects of colistin sulfate residue on soil microbial community structure].

    Science.gov (United States)

    Ma, Yi; Peng, Jin-Ju; Chen, Jin-Jun; Fan, Ting-Li; Sun, Yong-Xue

    2014-06-01

    By using fumigation extraction and phospholipid fatty acid (PLFA) methods, the change of characteristics of soil microbial community structure caused by residue of colistin sulfate (CS) was studied. The results showed that the CS (w(cs) > or = 5 mg x kg(-1)) had a significant effect on the microbial biomass carbon (MBC) and it was dose-dependent where MBC decreased with the increase of CS concentration in soil. The MBC in soil decreased by 52. 1% when the CS concentration reached 50 mg x kg(-1). The total PLFA of soil in each CS treatment was significantly decreased during the sampling period compared with the control group and showed a dose-dependent relationship. The soil microbial community structure and diversity in the low CS group (w(cs) = 0.5 mg x kg(-1)) were not significantly different from the control group on 7th and 49th day. However, they were significantly different on 21st and 35th day especially in the high CS group (w(cs) = 50 mg x kg(-1)). It was concluded that CS could change the structure of soil microorganisms and varied with time which might be caused by the chemical conversion and degradation of CS in soil.

  20. The microbial nitrogen cycling potential is impacted by polyaromatic hydrocarbon pollution of marine sediments.

    Science.gov (United States)

    Scott, Nicole M; Hess, Matthias; Bouskill, Nick J; Mason, Olivia U; Jansson, Janet K; Gilbert, Jack A

    2014-01-01

    During hydrocarbon exposure, the composition and functional dynamics of marine microbial communities are altered, favoring bacteria that can utilize this rich carbon source. Initial exposure of high levels of hydrocarbons in aerobic surface sediments can enrich growth of heterotrophic microorganisms having hydrocarbon degradation capacity. As a result, there can be a localized reduction in oxygen potential within the surface layer of marine sediments causing anaerobic zones. We hypothesized that increasing exposure to elevated hydrocarbon concentrations would positively correlate with an increase in denitrification processes and the net accumulation of dinitrogen. This hypothesis was tested by comparing the relative abundance of genes associated with nitrogen metabolism and nitrogen cycling identified in 6 metagenomes from sediments contaminated by polyaromatic hydrocarbons from the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico, and 3 metagenomes from sediments associated with natural oil seeps in the Santa Barbara Channel. An additional 8 metagenomes from uncontaminated sediments from the Gulf of Mexico were analyzed for comparison. We predicted relative changes in metabolite turnover as a function of the differential microbial gene abundances, which showed predicted accumulation of metabolites associated with denitrification processes, including anammox, in the contaminated samples compared to uncontaminated sediments, with the magnitude of this change being positively correlated to the hydrocarbon concentration and exposure duration. These data highlight the potential impact of hydrocarbon inputs on N cycling processes in marine sediments and provide information relevant for system scale models of nitrogen metabolism in affected ecosystems.

  1. The microbial nitrogen cycling potential in marine sediments is impacted by polyaromatic hydrocarbon pollution

    Directory of Open Access Journals (Sweden)

    Nicole M Scott

    2014-03-01

    Full Text Available During petroleum hydrocarbon exposure the composition and functional dynamics of marine microbial communities are altered, favoring bacteria that can utilize this rich carbon source. Initial exposure of high levels of hydrocarbons in aerobic surface sediments can enrich growth of heterotrophic microorganisms having hydrocarbon degradation capacity. As a result, there can be a localized reduction in oxygen potential, if the sediments are aerobic, within the surface layer of marine sediments resulting in anaerobic zones. We hypothesized that increasing exposure to elevated hydrocarbon concentrations would positively correlate with an increase in denitrification processes and the net accumulation of dinitrogen. This hypothesis was tested by comparing the relative abundance of genes associated with nitrogen metabolism and nitrogen cycling identified in 6 metagenomes from sediments contaminated by polyaromatic hydrocarbons from the Deepwater Horizon oil spill in the Gulf of Mexico, and 3 metagenomes from sediments associated with natural oil seeps in the Santa Barbara Channel. An additional 8 metagenomes from uncontaminated sediments from the Gulf of Mexico were analyzed for comparison. We predicted relative changes in metabolite turnover as a function of the differential microbial gene abundances, which showed predicted accumulation of metabolites associated with denitrification processes, including anammox, in the contaminated samples compared to uncontaminated sediments, with the magnitude of this change being positively correlated to the hydrocarbon concentration and exposure duration. These data highlight the potential impact of hydrocarbon inputs on N cycling processes in marine sediments and provide information relevant for system scale models of nitrogen metabolism in affected ecosystems.

  2. Microbial Degradation of Petroleum Hydrocarbon Contaminants: An Overview

    Directory of Open Access Journals (Sweden)

    Nilanjana Das

    2011-01-01

    Full Text Available One of the major environmental problems today is hydrocarbon contamination resulting from the activities related to the petrochemical industry. Accidental releases of petroleum products are of particular concern in the environment. Hydrocarbon components have been known to belong to the family of carcinogens and neurotoxic organic pollutants. Currently accepted disposal methods of incineration or burial insecure landfills can become prohibitively expensive when amounts of contaminants are large. Mechanical and chemical methods generally used to remove hydrocarbons from contaminated sites have limited effectiveness and can be expensive. Bioremediation is the promising technology for the treatment of these contaminated sites since it is cost-effective and will lead to complete mineralization. Bioremediation functions basically on biodegradation, which may refer to complete mineralization of organic contaminants into carbon dioxide, water, inorganic compounds, and cell protein or transformation of complex organic contaminants to other simpler organic compounds by biological agents like microorganisms. Many indigenous microorganisms in water and soil are capable of degrading hydrocarbon contaminants. This paper presents an updated overview of petroleum hydrocarbon degradation by microorganisms under different ecosystems.

  3. Microbial community response to a simulated hydrocarbon spill in mangrove sediments

    NARCIS (Netherlands)

    Taketani, Rodrigo Gouvea; Franco, Natalia Oliveira; Rosado, Alexandre Soares; van Elsas, Jan Dirk

    2010-01-01

    In this study, we examined the hypothesis that the microbial communities in mangrove sediments with different chemical and historical characteristics respond differently to the disturbance of a hydrocarbon spill. Two different mangrove sediments were sampled, one close to an oil refinery that had su

  4. Microbial community response to a simulated hydrocarbon spill in mangrove sediments

    NARCIS (Netherlands)

    Taketani, Rodrigo Gouvea; Franco, Natalia Oliveira; Rosado, Alexandre Soares; van Elsas, Jan Dirk

    In this study, we examined the hypothesis that the microbial communities in mangrove sediments with different chemical and historical characteristics respond differently to the disturbance of a hydrocarbon spill. Two different mangrove sediments were sampled, one close to an oil refinery that had

  5. Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils.

    Science.gov (United States)

    Aleer, Sam; Adetutu, Eric M; Weber, John; Ball, Andrew S; Juhasz, Albert L

    2014-04-01

    In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed.

  6. Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria

    Science.gov (United States)

    Tikilili, P. V.; Chirwa, E. M. N.

    2010-01-01

    Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.

  7. Heavy metal and chlorinated hydrocarbon residues in California sea loins (Zalophus californianus californianus)

    Energy Technology Data Exchange (ETDEWEB)

    Buhler, D.R.; Claeys, R.R.; Mate, B.R.

    1975-12-01

    Samples of various tissues and organs from healthy California sea lions (Zalophus californianus californianus) and sick animals (apparently with leptospirosis) collected along the central Oregon coast in 1970, 1971, and 1973 were analyzed for total mercury, methylmercury, cadmium, and chlorinated hydrocarbons. Maximum mercury concentrations of 74 to 170 ppM occurred in sea lion liver, but only 1.6 to 3.7 percent of this was present as methylmercury. Cadmium was concentrated primarily in the kidney which contained 7.2 to 12.0 ppM of the metal. Chlorinated hydrocarbon residues in sea lion fat ranged between 253 to 475 ppM DDE, and 21.2 and 34.1 ppM PCB. Although mercury, cadmium, and chlorinated hydrocarbon residues in some of the sick sea lions were significantly higher than those present in healthy animals, it is not possible to relate these differences to the onset of leptospirosis.

  8. Bioremediation of hydrocarbon degradation in a petroleum-contaminated soil and microbial population and activity determination.

    Science.gov (United States)

    Wu, Manli; Li, Wei; Dick, Warren A; Ye, Xiqiong; Chen, Kaili; Kost, David; Chen, Liming

    2017-02-01

    Bioremediation of hydrocarbon degradation in petroleum-polluted soil is carried out by various microorganisms. However, little information is available for the relationships between hydrocarbon degradation rates in petroleum-contaminated soil and microbial population and activity in laboratory assay. In a microcosm study, degradation rate and efficiency of total petroleum hydrocarbons (TPH), alkanes, and polycyclic aromatic hydrocarbons (PAH) in a petroleum-contaminated soil were determined using an infrared photometer oil content analyzer and a gas chromatography mass spectrometry (GC-MS). Also, the populations of TPH, alkane, and PAH degraders were enumerated by a modified most probable number (MPN) procedure, and the hydrocarbon degrading activities of these degraders were determined by the Biolog (MT2) MicroPlates assay. Results showed linear correlations between the TPH and alkane degradation rates and the population and activity increases of TPH and alkane degraders, but no correlation was observed between the PAH degradation rates and the PAH population and activity increases. Petroleum hydrocarbon degrading microbial population measured by MPN was significantly correlated with metabolic activity in the Biolog assay. The results suggest that the MPN procedure and the Biolog assay are efficient methods for assessing the rates of TPH and alkane, but not PAH, bioremediation in oil-contaminated soil in laboratory.

  9. Marine coastal sediments microbial hydrocarbon degradation processes: contribution of experimental ecology in the omics'era.

    Science.gov (United States)

    Cravo-Laureau, Cristiana; Duran, Robert

    2014-01-01

    Coastal marine sediments, where important biological processes take place, supply essential ecosystem services. By their location, such ecosystems are particularly exposed to human activities as evidenced by the recent Deepwater Horizon disaster. This catastrophe revealed the importance to better understand the microbial processes involved on hydrocarbon degradation in marine sediments raising strong interests of the scientific community. During the last decade, several studies have shown the key role played by microorganisms in determining the fate of hydrocarbons in oil-polluted sediments but only few have taken into consideration the whole sediment's complexity. Marine coastal sediment ecosystems are characterized by remarkable heterogeneity, owning high biodiversity and are subjected to fluctuations in environmental conditions, especially to important oxygen oscillations due to tides. Thus, for understanding the fate of hydrocarbons in such environments, it is crucial to study microbial activities, taking into account sediment characteristics, physical-chemical factors (electron acceptors, temperature), nutrients, co-metabolites availability as well as sediment's reworking due to bioturbation activities. Key information could be collected from in situ studies, which provide an overview of microbial processes, but it is difficult to integrate all parameters involved. Microcosm experiments allow to dissect in-depth some mechanisms involved in hydrocarbon degradation but exclude environmental complexity. To overcome these lacks, strategies have been developed, by creating experiments as close as possible to environmental conditions, for studying natural microbial communities subjected to oil pollution. We present here a review of these approaches, their results and limitation, as well as the promising future of applying "omics" approaches to characterize in-depth microbial communities and metabolic networks involved in hydrocarbon degradation. In addition, we

  10. Marine coastal sediments microbial hydrocarbon degradation processes: contribution of experimental ecology in the omics’era

    Directory of Open Access Journals (Sweden)

    Cristiana eCravo-Laureau

    2014-02-01

    Full Text Available Coastal marine sediments, where important biological processes take place, supply essential ecosystem services. By their location, such ecosystems are particularly exposed to human activities as evidenced by the recent Deepwater Horizon disaster. This catastrophe revealed the importance to better understand the microbial processes involved on hydrocarbon degradation in marine sediments raising strong interests of the scientific community. During the last decade, several studies have shown the key role played by microorganisms in determining the fate of hydrocarbons in oil-polluted sediments but only few have taken into consideration the whole sediment’s complexity. Marine coastal sediment ecosystems are characterized by remarkable heterogeneity, owning high biodiversity and are subjected to fluctuations in environmental conditions, especially to important oxygen oscillations due to tides. Thus, for understanding the fate of hydrocarbons in such environments, it is crucial to study microbial activities, taking into account sediment characteristics, physical-chemical factors (electron acceptors, temperature, nutrients, co-metabolites availability as well as sediment’s reworking due to bioturbation activities. Key information could be collected from in situ studies, which provide an overview of microbial processes, but it is difficult to integrate all parameters involved. Microcosm experiments allow to dissect in-depth some mechanisms involved in hydrocarbon degradation but exclude environmental complexity. To overcome these lacks, strategies have been developed, by creating experiments as close as possible to environmental conditions, for studying natural microbial communities subjected to oil pollution. We present here a review of these approaches, their results and limitation, as well as the promising future of applying ‘omics’ approaches to characterize in-depth microbial communities and metabolic networks involved in hydrocarbon

  11. 40 CFR 158.2172 - Experimental use permit microbial pesticides residue data requirements table.

    Science.gov (United States)

    2010-07-01

    ... pesticides residue data requirements table. 158.2172 Section 158.2172 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2172 Experimental use permit microbial pesticides residue data requirements table. (a)...

  12. Dynamic autoinoculation and the microbial ecology of a deep water hydrocarbon irruption.

    Science.gov (United States)

    Valentine, David L; Mezić, Igor; Maćešić, Senka; Črnjarić-Žic, Nelida; Ivić, Stefan; Hogan, Patrick J; Fonoberov, Vladimir A; Loire, Sophie

    2012-12-11

    The irruption of gas and oil into the Gulf of Mexico during the Deepwater Horizon event fed a deep sea bacterial bloom that consumed hydrocarbons in the affected waters, formed a regional oxygen anomaly, and altered the microbiology of the region. In this work, we develop a coupled physical-metabolic model to assess the impact of mixing processes on these deep ocean bacterial communities and their capacity for hydrocarbon and oxygen use. We find that observed biodegradation patterns are well-described by exponential growth of bacteria from seed populations present at low abundance and that current oscillation and mixing processes played a critical role in distributing hydrocarbons and associated bacterial blooms within the northeast Gulf of Mexico. Mixing processes also accelerated hydrocarbon degradation through an autoinoculation effect, where water masses, in which the hydrocarbon irruption had caused blooms, later returned to the spill site with hydrocarbon-degrading bacteria persisting at elevated abundance. Interestingly, although the initial irruption of hydrocarbons fed successive blooms of different bacterial types, subsequent irruptions promoted consistency in the structure of the bacterial community. These results highlight an impact of mixing and circulation processes on biodegradation activity of bacteria during the Deepwater Horizon event and suggest an important role for mixing processes in the microbial ecology of deep ocean environments.

  13. Effect of organic nutrient on microbial utilization of hydrocarbons on ...

    African Journals Online (AJOL)

    Administrator

    2006-05-16

    May 16, 2006 ... African Journal of Biotechnology Vol. 5 (10), pp. ... Full Length Research Paper. Effect of organic ... incident of oil spills occur in the mangrove swamp zones ..... methods for a number of residual fuel spill in Lee County, Florida.

  14. Microbial communities along biogeochemical gradients in a hydrocarbon-contaminated aquifer.

    Science.gov (United States)

    Tischer, Karolin; Kleinsteuber, Sabine; Schleinitz, Kathleen M; Fetzer, Ingo; Spott, Oliver; Stange, Florian; Lohse, Ute; Franz, Janett; Neumann, Franziska; Gerling, Sarah; Schmidt, Christian; Hasselwander, Eyk; Harms, Hauke; Wendeberg, Annelie

    2013-09-01

    Micro-organisms are known to degrade a wide range of toxic substances. How the environment shapes microbial communities in polluted ecosystems and thus influences degradation capabilities is not yet fully understood. In this study, we investigated microbial communities in a highly complex environment: the capillary fringe and subjacent sediments in a hydrocarbon-contaminated aquifer. Sixty sediment sections were analysed using terminal restriction fragment length polymorphism (T-RFLP) fingerprinting, cloning and sequencing of bacterial and archaeal 16S rRNA genes, complemented by chemical analyses of petroleum hydrocarbons, methane, oxygen and alternative terminal electron acceptors. Multivariate statistics revealed concentrations of contaminants and the position of the water table as significant factors shaping the microbial community composition. Micro-organisms with highest T-RFLP abundances were related to sulphate reducers belonging to the genus Desulfosporosinus, fermenting bacteria of the genera Sedimentibacter and Smithella, and aerobic hydrocarbon degraders of the genus Acidovorax. Furthermore, the acetoclastic methanogens Methanosaeta, and hydrogenotrophic methanogens Methanocella and Methanoregula were detected. Whereas sulphate and sulphate reducers prevail at the contamination source, the detection of methane, fermenting bacteria and methanogenic archaea further downstream points towards syntrophic hydrocarbon degradation. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  15. Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia.

    Science.gov (United States)

    Shen, Tiantian; Pi, Yongrui; Bao, Mutai; Xu, Nana; Li, Yiming; Lu, Jinren

    2015-12-01

    The efficiencies of free and immobilized microbial consortia in the degradation of different types of petroleum hydrocarbons were investigated. In this study, the biodegradation rates of naphthalene, phenanthrene, pyrene and crude oil reached about 80%, 30%, 56% and 48% under the optimum environmental conditions of free microbial consortia after 7 d. We evaluated five unique co-metabolic substances with petroleum hydrocarbons, α-lactose was the best co-metabolic substance among glucose, α-lactose, soluble starch, yeast powder and urea. The orthogonal biodegradation analysis results showed that semi-coke was the best immobilized carrier followed by walnut shell and activated carbon. Meanwhile, the significance of various factors that contribute to the biodegradation of semi-coke immobilized microbial consortia followed the order of: α-lactose > semi-coke > sodium alginate > CaCl2. Moreover, the degradation rate of the immobilized microbial consortium (47%) was higher than that of a free microbial consortium (26%) under environmental conditions such as the crude oil concentration of 3 g L(-1), NaCl concentration of 20 g L(-1), pH at 7.2-7.4 and temperature of 25 °C after 5 d. SEM and FTIR analyses revealed that the structure of semi-coke became more porous and easily adhered to the microbial consortium; the functional groups (e.g., hydroxy and phosphate) were identified in the microbial consortium and were changed by immobilization. This study demonstrated that the ability of microbial adaptation to the environment can be improved by immobilization which expands the application fields of microbial remediation.

  16. In situ recovery from residually heated sections in a hydrocarbon containing formation

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX); Ryan, Robert Charles (Houston, TX)

    2010-12-14

    Methods of treating a tar sands formation is described herein. The methods may include providing heat to a first section of a hydrocarbon layer in the formation from a plurality of heaters located in the first section of the formation. Heat is transferred from the heaters so that at least a first section of the formation reaches a selected temperature. At least a portion of residual heat from the first section transfers from the first section to a second section of the formation. At least a portion of hydrocarbons in the second section are mobilized by providing a solvation fluid and/or a pressurizing fluid to the second section of the formation.

  17. Approach for estimating microbial growth and the biodegradation of hydrocarbon contaminants in subsoil based on field measurements: 1. Model development and verification.

    Science.gov (United States)

    Song, Dejun; Katayama, Arata

    2010-01-15

    An approach was developed to represent the microbial growth and corresponding biodegradation of hydrocarbons (HCs) during the natural attenuation process based on field measurements of in situ microbial biomass and residual HC concentrations in unsaturated subsurface soil. A kinetic model combining Monod and logistic kinetics represents microbial growth under the limitation of HCs as substrates and environmental factors at actual contaminated sites by the introduction of two new kinetic parameters, the effective rate and the self-limiting coefficient of microbial growth. The correspondence between microbial growth and the biodegradation of HCs in the soil is obtained by dividing the amount of HC and the corresponding degrading microbial groups into two classes: saturated HCs as inert components and aromatic HCs that form a contamination plume as dissolved components. The respiratory quinones were used as indicators of microbial biomass. The biodegradation capacity of contaminated sites was evaluated by the maximum microbial biomass obtained by field measurements, which is considered as the integrated results from measurements of HCs, degrading kinetics, and environmental factors at the site. The feasibility of the proposed approach was verified at two hypothetical contaminated sites. The results suggested that the proposed approach is feasible for application at actual HC-contaminated sites.

  18. Effect of Kelp Residue Microbial Fertilizer on Eco-Control Peanut Pathogenic Fungus Aspergillus Parasiticus 1

    Institute of Scientific and Technical Information of China (English)

    Wei Xiao; Peisheng Yan

    2016-01-01

    Ecological prevention and control of plant disease is very important in sustainable agriculture. Adjusting soil pH value and fertilizing organic microbial fertilizer are two effective measures in this process. Kelp residue contains a large amount of organic compounds and alkaline metal ions. The bio⁃control Bacillus amyloliquefaciens strain Hitwh⁃BA2 was inoculated into kelp residue medium to produce kelp residue microbial fertilizer. Acidic soil and alkaline soil were used to study the effect of kelp residue microbial fertilizer on soil pH and soil suppressive activity. Tip⁃culture method was used to determine soil leachate suppressive activity, which characterized the soil suppressive activity. Results showed that fertilizing kelp residue microbial fertilizer had increased the soil pH and soil suppressive ability significantly, which was verified by peanut validation experiments as well. Peanut potting experiments proved that fertilizing kelp residue microbial fertilizer not only improved the yield of peanuts obviously, but also reduced the amount of Aspergillus parasiticus 95 in peanut geocarposphere soil significantly. Results also showed that fertilizing kelp residue microbial fertilizer was effective in reducing A. parasiticus 95 infection rate. So the kelp residue microbial fertilizer has good potential application prospect on ecological prevention and control of plant disease.

  19. Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wan, Chunli; Du, Maoan; Lee, Duu-Jong; Yang, Xue; Ma, Wencheng; Zheng, Lina

    2011-03-01

    Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m(-1) for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field.

  20. Microbial community succession in alkaline, saline bauxite residue: a cross-refinery study

    Science.gov (United States)

    Santini, T.; Malcolm, L. I.; Tyson, G. W.; Warren, L. A.

    2015-12-01

    Bauxite residue, a byproduct of the Bayer process for alumina refining, is an alkaline, saline tailings material that is generally considered to be inhospitable to microbial life. In situ remediation strategies promote soil formation in bauxite residue by enhancing leaching of saline, alkaline pore water, and through incorporation of amendments to boost organic matter content, decrease pH, and improve physical structure. The amelioration of chemical and physical conditions in bauxite residue is assumed to support diversification of microbial communities from narrow, poorly functioning microbial communities towards diverse, well-functioning communities. This study aimed to characterise microbial communities in fresh and remediated bauxite residues from refineries worldwide, to identify (a) whether initial microbial communities differed between refineries; (b) major environmental controls on microbial community composition; and (c) whether remediation successfully shifts the composition of microbial communities in bauxite residue towards those found in reference (desired endpoint) soils. Samples were collected from 16 refineries and characterised using 16S amplicon sequencing to examine microbial community composition and structure, in conjunction with physicochemical analyses. Initial microbial community composition was similar across refineries but partitioned into two major groups. Microbial community composition changes slowly over time and indicates that alkalinity and salinity inhibit diversification. Microbially-based strategies for in situ remediation should consider the initial microbial community composition and whether the pre-treatment of chemical properties would optimise subsequent bioremediation outcomes. During in situ remediation, microbial communities become more diverse and develop wider functional capacity, indicating progression towards communities more commonly observed in natural grassland and forest soils.

  1. Microbial adhesion to hydrocarbons: twenty-five years of doing MATH.

    Science.gov (United States)

    Rosenberg, Mel

    2006-09-01

    Twenty-five years ago this past autumn, we published a short article entitled 'Adherence of bacteria to hydrocarbons: a simple method for measuring cell-surface hydrophobicity' in Volume 9 of FEMS Microbiology Letters. Together with my Ph.D. supervisors, Eugene Rosenberg and David Gutnick, we proposed a method of measuring bacterial cell surface hydrophobicity based on bacterial adherence to hydrocarbon ('BATH', later known as 'MATH', for microbial adhesion to hydrocarbon). The method became popular soon after it was published, and the paper was, for at least the following decade, the Journal's most cited article. It became an ISI 'citation classic' in 1991. This minireview is a rather personal look at the development of the method and its various modifications and other scientific offspring, with the perspective of a quarter-century.

  2. Recent studies in microbial degradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Babu Zhereppa Fathepure

    2014-04-01

    Full Text Available Many hypersaline environments are often contaminated with petroleum compounds. Among these, oil and natural gas production sites all over the world and hundreds of kilometers of coastlines in the more arid regions of Gulf countries are of major concern due to the extent and magnitude of contamination. Because conventional microbiological processes do not function well at elevated salinities, bioremediation of hypersaline environments can only be accomplished using high salt-tolerant microorganisms capable of degrading petroleum compounds. In the last two decades, there have been many reports on the biodegradation of hydrocarbons in moderate to high salinity environments. Numerous microorganisms belonging to the domain Bacteria and Archaea have been isolated and their phylogeny and metabolic capacity to degrade a variety of aliphatic and aromatic hydrocarbons in varying salinities have been demonstrated. This article focuses on our growing understanding of bacteria and archaea responsible for the degradation of hydrocarbons under aerobic conditions in moderate to high salinity conditions. Even though organisms belonging to various genera have been shown to degrade hydrocarbons, members of the genera Halomonas Alcanivorax, Marinobacter, Haloferax, Haloarcula, and Halobacterium dominate the published literature. Despite rapid advances in understanding microbial taxa that degrade hydrocarbons under aerobic conditions, not much is known about organisms that carry out similar processes in anaerobic conditions. Also, information on molecular mechanisms and pathways of hydrocarbon degradation in high salinity is scarce and only recently there have been a few reports describing genes, enzymes and breakdown steps for some hydrocarbons. These limited studies have clearly revealed that degradation of oxygenated and non-oxygenated hydrocarbons by halophilic and halotolerant microorganisms occur by pathways similar to those found in non-halophiles.

  3. Study on bioadsorption and biodegradation of petroleum hydrocarbons by a microbial consortium.

    Science.gov (United States)

    Xu, Nana; Bao, Mutai; Sun, Peiyan; Li, Yiming

    2013-12-01

    A microbial consortium isolated from Shengli oilfield polluted sludge was capable of degrading naphthalene (NAP), phenanthrene (PHE), pyrene (PYR) and crude oil. It performed high biodegradation activity and emulsifiability for petroleum hydrocarbons, and was tolerant to 6.2mM Cu(2+), 2.7 mM Zn(2+) and 9.5mM Pb(2+). Biodegradation rates of NAP, PHE, PYR and crude oil were 53%, 21%, 32% and 44% in the presence of heavy metal (Cu(2+), 1.7 mM and Zn(2+), 2mM), respectively. Exploration on the adsorption and uptake of petroleum hydrocarbons by microbe suggested the stability of surface adsorption and cell uptake by live microbial consortium followed a decreasing order of NAP > PHE ≈ PYR > crude oil. The adsorption by heat-killed microbial consortium was constant for PAHs, while decreased for crude oil. Experiments on enzymatic degradation indicated that the metabolic efficiency of periplasmic, cytoplasmic and extracellular enzymes secreted by the microbial consortium for diverse substrates was different.

  4. Horizontal arrangement of anodes of microbial fuel cells enhances remediation of petroleum hydrocarbon-contaminated soil.

    Science.gov (United States)

    Zhang, Yueyong; Wang, Xin; Li, Xiaojing; Cheng, Lijuan; Wan, Lili; Zhou, Qixing

    2015-02-01

    With the aim of in situ bioremediation of soil contaminated by hydrocarbons, anodes arranged with two different ways (horizontal or vertical) were compared in microbial fuel cells (MFCs). Charge outputs as high as 833 and 762C were achieved in reactors with anodes horizontally arranged (HA) and vertically arranged (VA). Up to 12.5 % of the total petroleum hydrocarbon (TPH) was removed in HA after 135 days, which was 50.6 % higher than that in VA (8.3 %) and 95.3 % higher than that in the disconnected control (6.4 %). Hydrocarbon fingerprint analysis showed that the degradation rates of both alkanes and polycyclic aromatic hydrocarbons (PAHs) in HA were higher than those in VA. Lower mass transport resistance in the HA than that of the VA seems to result in more power and more TPH degradation. Soil pH was increased from 8.26 to 9.12 in HA and from 8.26 to 8.64 in VA, whereas the conductivity was decreased from 1.99 to 1.54 mS/cm in HA and from 1.99 to 1.46 mS/cm in VA accompanied with the removal of TPH. Considering both enhanced biodegradation of hydrocarbon and generation of charge in HA, the MFC with anodes horizontally arranged is a promising configuration for future applications.

  5. The lack of microbial degradation of polycyclic aromatic hydrocarbons from coal-rich soils

    Energy Technology Data Exchange (ETDEWEB)

    Achten, C.; Cheng, S.B.; Straub, K.L.; Hofmann, T. [University of Vienna, Vienna (Austria)

    2011-02-02

    Analytical techniques used to assess the environmental risk of contamination from polycyclic aromatic hydrocarbons (PAHs) typically consider only abiotic sample parameters. Supercritical fluid extraction and sorption enthalpy experiments previously suggested slow desorption rates for PAH compounds in two coal-contaminated floodplain soils. In this study, the actual PAH availability for aerobic soil microorganisms was tested in two series of soil-slurry experiments. The experimental conditions supported microbial degradation of phenanthrene if it was weakly sorbed onto silica gel. Native coals and coal-derived particles in two soils effectively acted as very strong sorbents and prevented microbial PAH degradation. The long history of PAH exposure and degree of coal contamination apparently had no influence on the capability of the microbial soil community to overcome constraints of PAH availability. Within the context of the experimental conditions and the compounds chosen, our results confirm that coal-bound PAHs are not bioavailable and hence of low environmental concern.

  6. Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors.

    Science.gov (United States)

    Gassara, Fatma; Suri, Navreet; Stanislav, Paul; Voordouw, Gerrit

    2015-10-20

    Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.6 mM for toluene) is injected to improve the nitrate reduction capacity of the oil along the water flow path, followed by injection of nitrate, other nutrients (e.g., phosphate) and a consortium of NRB, if necessary. Hydrocarbon- and nitrate-mediated MEOR was tested in low- and high-pressure, water-wet sandpack bioreactors with 0.5 pore volumes of residual oil in place (ROIP). Compared to control bioreactors, those with 11-12 mM of toluene in the oil (gained by direct addition or by aqueous injection) and 80 mM of nitrate in the aqueous phase produced 16.5 ± 4.4% of additional ROIP (N = 10). Because toluene is a cheap commodity chemical, HN-MEOR has the potential to be a cost-effective method for additional oil production even in the current low oil price environment.

  7. Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons

    Science.gov (United States)

    Mykhailova, Larysa; Fischer, Thomas; Iurchenko, Valentina

    2015-04-01

    It has been demonstrated previously that hydrocarbon addition to soil provokes soil organic matter priming (Zyakun et al., 2011). It has further been shown that petroleum hydrocarbons deposit to roadside soils bound to fine mineral particles and together with vehicle spray (Mykhailova et al., 2014), and that hydrocarbon concentrations decrease to safe levels within the first 15 m from the road, reaching background concentrations at 60-100 m distance (Mykhailova et al., 2013). It was the aim of this study to (I) identify the bioavailability of different petroleum hydrocarbon fractions to degradation and to (II) identify the native (i.e. pedogenic) C fraction affected by hydrocarbon-mediated soil organic matter priming during decay. To address this aim, we collected soil samples at distances from 1 to 100 m (sampling depth 15 cm) near the Traktorostroiteley avenue and the Pushkinskaya street in Kharkov, as well as near the country road M18 near Kharkov, Ukraine. The roads have been under exploitation for several decades, so microbial adaptation to enhanced hydrocarbon levels and full expression of effects could be assumed. The following C fractions were quantified using 13C-CP/MAS-NMR: Carbohydrates, Proteins, Lignin, Aliphates, Carbonyl/Carboxyl as well as black carbon according to Nelson and Baldock (2005). Petroleum hydrocarbons were determind after hexane extraction using GC-MS and divided into a light fraction (chain-length C27, Mykhailova et al., 2013). Potential soil respiration was determined every 48 h by trapping of CO2 evolving from 20 g soil in NaOH at 20 ° C and at 60% of the maximum water holding capacity and titration after a total incubation period of 4 weeks in the lab. It was found that soil respiration positively correlated with the ratio of the light fraction to the sum of medium and heavy fractions of petroleum hydrocarbons, which indicates higher biodegradation primarily of the light petroleum hydrocarbon fraction. Further, soil respiration was

  8. Freezing and hungry? Hydrocarbon degrading microbial communities in Barents Sea sediments around Svalbard

    Science.gov (United States)

    Krueger, Martin; Straaten, Nontje

    2017-04-01

    The Polar Regions are characterised by varying temperatures and changing ice coverage, so most of the primary production take place in the warmer season. Consequently, sedimentation rates and nutrient input are low. The diversity and metabolic potentials of the microbial communities inhabiting these sediments in the Northern Barents Sea are largely unknown. Recent reports on natural methane seeps as well as the increase in hydrocarbon exploration activities in the Arctic initiated our studies on the potential of indigenous microbial communities to degrade methane and higher hydrocarbons under in situ pressure and temperature conditions. Furthermore, the subseafloor geochemistry in these areas was studied, together with important microbial groups, like methanotrophs, methanogens, metal and sulfate reducers, which may drive seafloor ecosystems in the Northern Barents Sea. Sediment samples were collected in several areas around Svalbard in the years 2013-2016 ranging from shallow (200m) areas on the Svalbard shelf to deep sea areas on the eastern Yermak Plateau (3200m water depths). Shelf sediments showed the highest organic carbon content which decreased with increasing depths. Iron and manganese as potential electron acceptors were found in the porewater especially in the top 50 cm of the cores, while sulfate was always present in substantial amounts in porewater samples down to the end of the up to two metre long cores. Concentrations of dissolved methane and carbon dioxide were low. The potential of the indigenous microorganisms to degrade methane and higher hydrocarbons as well as different oils under in situ temperatures and pressures was widespread in surface sediments. Degradation rates were higher under aerobic than under anaerobic conditions, and decreased with increasing sediment as well as water depths. Similar pattern were found for other metabolic processes, including sulfate, Fe and Mn reduction as well as carbon dioxide and methane production rates

  9. [Compositions and residual properties of petroleum hydrocarbon in contaminated soil of the oilfields].

    Science.gov (United States)

    Hu, Di; Li, Chuan; Dong, Qian-Qian; Li, Li-Ming; Li, Guang-He

    2014-01-01

    The aims of this study were to determine the compositions and residual properties of petroleum hydrocarbon in soil, as well as to identify the source and weathering degree of the pollution. A total of 5 producing wells in Gudao and Hekou oil producing region of Shengli oilfields were analyzed. More than 50 individual target compounds including straight-and branched-chain alkanes( n-alkanes, pristine and phytane) and polycyclic aromatic hydrocarbons (PAHs) in soil samples and crude oil were determined by gas chromatography-mass spectrometry (GC-MS). The percentages of chain alkanes and PAHs in total solvent extractable matters(TSEM) of soil samples were both much lower than those in the crude oil samples. The compositions of petroleum hydrocarbon in soil samples differed from those in crude oil, which indicated the n-alkanes with carbon numbers oil contaminated soils, the relationship between the index and petroleum hydrocarbon compounds was analyzed using principal component analysis (PCA). The results showed that the n-alkanes with carbon numbers > 33 and the PAHs with rings between 3 and 5 were much harder to degrade. PCA of 4 indexes for source identification revealed more than 50% of the soil samples were polluted by crude oil, which needs more attention during remediation.

  10. Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baoliang, E-mail: blchen@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Yuan Miaoxin; Liu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2011-04-15

    Graphical abstract: The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants. Research highlights: {yields} Polycyclic aromatic hydrocarbons are effectively removed by plant residues. {yields} Biosorption mechanism of plant residues to abate PAHs is a partitioning process. {yields} Partition coefficients are negatively related with sugar contents of biosorbent. {yields} The aromatic component and K{sub ow} exhibit positive effects on biosorption. {yields} The structure-effect relationship guides plant residue using as a biosorbent. - Abstract: To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N{sub 2} surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K{sub d}) followed the order of PN > BL > OP > RR > WC, ranged from 2484 {+-} 24.24 to 5306 {+-} 92.49 L/kg. Except the WC sample, the K{sub d} values were negatively correlated with sugar content, polar index [(N + O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K{sub oc}) were linearly correlated with octanol-water partition coefficients (K{sub ow}) of PAHs, i.e., log K{sub oc} = 1.16 log K{sub ow} - 1.21. The structure-effect relationship provides a reference to select and modify plant residues as a

  11. New hydrocarbon degradation pathways in the microbial metagenome from Brazilian petroleum reservoirs.

    Directory of Open Access Journals (Sweden)

    Isabel Natalia Sierra-García

    Full Text Available Current knowledge of the microbial diversity and metabolic pathways involved in hydrocarbon degradation in petroleum reservoirs is still limited, mostly due to the difficulty in recovering the complex community from such an extreme environment. Metagenomics is a valuable tool to investigate the genetic and functional diversity of previously uncultured microorganisms in natural environments. Using a function-driven metagenomic approach, we investigated the metabolic abilities of microbial communities in oil reservoirs. Here, we describe novel functional metabolic pathways involved in the biodegradation of aromatic compounds in a metagenomic library obtained from an oil reservoir. Although many of the deduced proteins shared homology with known enzymes of different well-described aerobic and anaerobic catabolic pathways, the metagenomic fragments did not contain the complete clusters known to be involved in hydrocarbon degradation. Instead, the metagenomic fragments comprised genes belonging to different pathways, showing novel gene arrangements. These results reinforce the potential of the metagenomic approach for the identification and elucidation of new genes and pathways in poorly studied environments and contribute to a broader perspective on the hydrocarbon degradation processes in petroleum reservoirs.

  12. New Hydrocarbon Degradation Pathways in the Microbial Metagenome from Brazilian Petroleum Reservoirs

    Science.gov (United States)

    Sierra-García, Isabel Natalia; Correa Alvarez, Javier; Pantaroto de Vasconcellos, Suzan; Pereira de Souza, Anete; dos Santos Neto, Eugenio Vaz; de Oliveira, Valéria Maia

    2014-01-01

    Current knowledge of the microbial diversity and metabolic pathways involved in hydrocarbon degradation in petroleum reservoirs is still limited, mostly due to the difficulty in recovering the complex community from such an extreme environment. Metagenomics is a valuable tool to investigate the genetic and functional diversity of previously uncultured microorganisms in natural environments. Using a function-driven metagenomic approach, we investigated the metabolic abilities of microbial communities in oil reservoirs. Here, we describe novel functional metabolic pathways involved in the biodegradation of aromatic compounds in a metagenomic library obtained from an oil reservoir. Although many of the deduced proteins shared homology with known enzymes of different well-described aerobic and anaerobic catabolic pathways, the metagenomic fragments did not contain the complete clusters known to be involved in hydrocarbon degradation. Instead, the metagenomic fragments comprised genes belonging to different pathways, showing novel gene arrangements. These results reinforce the potential of the metagenomic approach for the identification and elucidation of new genes and pathways in poorly studied environments and contribute to a broader perspective on the hydrocarbon degradation processes in petroleum reservoirs. PMID:24587220

  13. Self-potential and Complex Conductivity Monitoring of In Situ Hydrocarbon Remediation in Microbial Fuel Cell

    Science.gov (United States)

    Zhang, C.; Revil, A.; Ren, Z.; Karaoulis, M.; Mendonca, C. A.

    2013-12-01

    Petroleum hydrocarbon contamination of soil and groundwater in both non-aqueous phase liquid and dissolved forms generated from spills and leaks is a wide spread environmental issue. Traditional cleanup of hydrocarbon contamination in soils and ground water using physical, chemical, and biological remedial techniques is often expensive and ineffective. Recent studies show that the microbial fuel cell (MFC) can simultaneously enhance biodegradation of hydrocarbons in soil and groundwater and yield electricity. Non-invasive geophysical techniques such as self-potential (SP) and complex conductivity (induced polarization) have shown the potential to detect and characterize the nature of electron transport mechanism of in situ bioremediation of organic contamination plumes. In this study, we deployed both SP and complex conductivity in lab scale MFCs to monitor time-laps geophysical response of degradation of hydrocarbons by MFC. Two different sizes of MFC reactors were used in this study (DI=15 cm cylinder reactor and 94.5cm x 43.5 cm rectangle reactor), and the initial hydrocarbon concentration is 15 g diesel/kg soil. SP and complex conductivity measurements were measured using non-polarizing Ag/AgCl electrodes. Sensitivity study was also performed using COMSOL Multiphysics to test different electrode configurations. The SP measurements showed stronger anomalies adjacent to the MFC than locations afar, and both real and imaginary parts of complex conductivity are greater in areas close to MFC than areas further away and control samples without MFC. The joint use of SP and complex conductivity could in situ evaluate the dynamic changes of electrochemical parameters during this bioremediation process at spatiotemporal scales unachievable with traditional sampling methods. The joint inversion of these two methods to evaluate the efficiency of MFC enhanced hydrocarbon remediation in the subsurface.

  14. Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment.

    Science.gov (United States)

    Rabus, Ralf; Boll, Matthias; Heider, Johann; Meckenstock, Rainer U; Buckel, Wolfgang; Einsle, Oliver; Ermler, Ulrich; Golding, Bernard T; Gunsalus, Robert P; Kroneck, Peter M H; Krüger, Martin; Lueders, Tillmann; Martins, Berta M; Musat, Florin; Richnow, Hans H; Schink, Bernhard; Seifert, Jana; Szaleniec, Maciej; Treude, Tina; Ullmann, G Matthias; Vogt, Carsten; von Bergen, Martin; Wilkes, Heinz

    2016-01-01

    Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl)succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and

  15. Microbial screening methods for detection of antibiotic residues in slaughter animals

    NARCIS (Netherlands)

    Pikkemaat, M.G.

    2009-01-01

    Monitoring of food products from animal origin for the presence of antimicrobial residues is preferably done using microbial screening methods because of their high cost-effectiveness. Traditionally applied methods fail to detect the maximum residue limits which were established when EU Council Regu

  16. Profiling of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing wastewater

    Institute of Scientific and Technical Information of China (English)

    LIAO Bo; JI Guodong; CHENG Liqiu

    2008-01-01

    A technology of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing (HSC) wastewater. The results showed that the heterotrophic genus of Acinetobacter and the autotrophic genera of Thiobacillus and Thiomonas could survive well in all of three operating conditions. Some special genera were also observed with changes of micro-ecoenvironment in the reactor, such as the halophilic genus of Nesterenkonia. Further, a new genus was found in the reactor, which was likely to have the ability to degrade sulfide and hydrocarbon at the same time. All of these detected and the new found genera have widely applicable potential in the treatment of HSC wastewater.

  17. Residues of petroleum hydrocarbons in tissues of sea turtles exposed to the IXTOC I oil spill

    Science.gov (United States)

    Hall, R.J.; Belisle, A.A.; Sileo, L.

    1983-01-01

    Sea turtles found dead when the Ixtoc I oil spill reached Texas waters were necropsied and tissues were analyzed for residues of petroleum hydrocarbons. Two of the three turtles were in poor flesh, but had no apparent oil-caused lesions. There was evidence of oil in all tissues examined and indications that the exposure had been chronic. Comparisons with results of studies done on birds indicate consumption of 50,000 ppm or more of oil in the diet. Some possible mechanisms of mortality are suggested.

  18. Diversity, distribution and hydrocarbon biodegradation capabilities of microbial communities in oil-contaminated cyanobacterial mats from a constructed wetland.

    Directory of Open Access Journals (Sweden)

    Raeid M M Abed

    Full Text Available Various types of cyanobacterial mats were predominant in a wetland, constructed for the remediation of oil-polluted residual waters from an oil field in the desert of the south-eastern Arabian Peninsula, although such mats were rarely found in other wetland systems. There is scarce information on the bacterial diversity, spatial distribution and oil-biodegradation capabilities of freshwater wetland oil-polluted mats. Microbial community analysis by Automated Ribosomal Spacer Analysis (ARISA showed that the different mats hosted distinct microbial communities. Average numbers of operational taxonomic units (OTUsARISA were relatively lower in the mats with higher oil levels and the number of shared OTUsARISA between the mats was 90% of the sequences affiliated to Proteobacteria (41% of total sequences, Cyanobacteria (31%, Bacteriodetes (11.5%, Planctomycetes (7% and Chloroflexi (3%. Known autotrophic (e.g. Rivularia and heterotrophic (e.g. Azospira nitrogen-fixing bacteria as well as purple sulfur and non-sulfur bacteria were frequently encountered in all mats. On the other hand, sequences of known sulfate-reducing bacteria (SRBs were rarely found, indicating that SRBs in the wetland mats probably belong to yet-undescribed novel species. The wetland mats were able to degrade 53-100% of C12-C30 alkanes after 6 weeks of incubation under aerobic conditions. We conclude that oil and ammonia concentrations are the major key players in determining the spatial distribution of the wetland mats' microbial communities and that these mats contribute directly to the removal of hydrocarbons from oil field wastewaters.

  19. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil

    DEFF Research Database (Denmark)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J

    2006-01-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63...... for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.......) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several...

  20. Microbial conversion of higher hydrocarbons to methane in oil and coal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Martin; Beckmaann, Sabrina; Siegert, Michael; Grundger, Friederike; Richnow, Hans [Geomicrobiology Group, Federal Institute for Geosciences and Natural Resources (Germany)

    2011-07-01

    In recent years, oil production has increased enormously but almost half of the oil now remaining is heavy/biodegraded and cannot be put into production. There is therefore a need for new technology and for diversification of energy sources. This paper discusses the microbial conversion of higher hydrocarbons to methane in oil and coal reservoirs. The objective of the study is to identify microbial and geochemical controls on methanogenesis in reservoirs. A graph shows the utilization of methane for various purposes in Germany from 1998 to 2007. A degradation process to convert coal to methane is shown using a flow chart. The process for converting oil to methane is also given. Controlling factors include elements such as Fe, nitrogen and sulfur. Atmospheric temperature and reservoir pressure and temperature also play an important role. From the study it can be concluded that isotopes of methane provide exploration tools for reservoir selection and alkanes and aromatic compounds provide enrichment cultures.

  1. Hydrocarbon biodegradation by Arctic sea-ice and sub-ice microbial communities during microcosm experiments, Northwest Passage (Nunavut, Canada).

    Science.gov (United States)

    Garneau, Marie-Ève; Michel, Christine; Meisterhans, Guillaume; Fortin, Nathalie; King, Thomas L; Greer, Charles W; Lee, Kenneth

    2016-10-01

    The increasing accessibility to navigation and offshore oil exploration brings risks of hydrocarbon releases in Arctic waters. Bioremediation of hydrocarbons is a promising mitigation strategy but challenges remain, particularly due to low microbial metabolic rates in cold, ice-covered seas. Hydrocarbon degradation potential of ice-associated microbes collected from the Northwest Passage was investigated. Microcosm incubations were run for 15 days at -1.7°C with and without oil to determine the effects of hydrocarbon exposure on microbial abundance, diversity and activity, and to estimate component-specific hydrocarbon loss. Diversity was assessed with automated ribosomal intergenic spacer analysis and Ion Torrent 16S rRNA gene sequencing. Bacterial activity was measured by (3)H-leucine uptake rates. After incubation, sub-ice and sea-ice communities degraded 94% and 48% of the initial hydrocarbons, respectively. Hydrocarbon exposure changed the composition of sea-ice and sub-ice communities; in sea-ice microcosms, Bacteroidetes (mainly Polaribacter) dominated whereas in sub-ice microcosms, the contribution of Epsilonproteobacteria increased, and that of Alphaproteobacteria and Bacteroidetes decreased. Sequencing data revealed a decline in diversity and increases in Colwellia and Moritella in oil-treated microcosms. Low concentration of dissolved organic matter (DOM) in sub-ice seawater may explain higher hydrocarbon degradation when compared to sea ice, where DOM was abundant and composed of labile exopolysaccharides.

  2. Microbial community analysis of soils contaminated with lead, chromium and petroleum hydrocarbons.

    Science.gov (United States)

    Joynt, Janet; Bischoff, Marianne; Turco, Ron; Konopka, Allan; Nakatsu, Cindy H

    2006-02-01

    The impact on the microbial community of long-term environmental exposure to metal and organic contamination was investigated. Twenty-four soil samples were collected along a transect dug in soils contaminated with road paint and paint solvents, mainly toluene. Chemical analysis along the transect revealed a range from high to low concentrations of metals (lead and chromium) and organic solvent compounds. Principal components analysis of microbial community structure based on denaturing gradient gel electrophoresis of the V3 region of the 16S rRNA gene and fatty acid methyl esters derived from phospholipids (phospholipid fatty acid analysis) showing samples with similar fingerprints also had similar contaminant concentrations. There was also a weak positive correlation between microbial biomass and the organic carbon concentration. Results indicated that microbial populations are present despite some extreme contaminant levels in this mixed-waste contaminated site. Nucleotide sequence determination of the 16S rRNA gene indicated the presence of phylogenetically diverse bacteria belonging to the alpha-, beta-, gamma-, and delta-Proteobacteria, the high and low G + C Gram-positive bacteria, green nonsulfur, OP8, and others that did not group within a described division. This indicates that soils contaminated with both heavy metals and hydrocarbons for several decades have undergone changes in community composition, but still contain a phylogenetically diverse group of bacteria (including novel phylotypes) that warrant further investigation.

  3. Biodegradation of the low concentration of polycyclic aromatic hydrocarbons in soil by microbial consortium during incubation.

    Science.gov (United States)

    Li, Xiaojun; Lin, Xin; Li, Peijun; Liu, Wan; Wang, Li; Ma, Fang; Chukwuka, K S

    2009-12-30

    The biodegradation of polycyclic aromatic hydrocarbons (PAHs) (8.15 mg PAHs kg(-1) soil) in aged contaminated soil by isolated microbial consortium (five fungi and three bacteria) during the incubation of 64d is reported. The applied treatments were: (1) biodegradation by adding microbial consortium in sterile soils (BM); (2) biodegradation by adding microbial consortium in non-sterile soils (BMN); and (3) biodegradation by in situ "natural" microbes in non-sterile soils (BNN). The fungi in BM and BMN soils grew rapidly 0-4d during the incubation and then reached a relative equilibrium. In contrast the fungi in BNN soil remained at a constant level for the entire time. Comparison with the fungi, the bacteria in BNN soils grew rapidly during the incubation 0-2d and then reached a relative equilibrium, and those in BM and BMN soils grew slowly during the incubation of 64 d. After 64 d of incubation, the PAH biodegradations were 35%, 40.7% and 41.3% in BNN, BMN and BM, respectively. The significant release of sequestrated PAHs in aged contaminated soil was observed in this experiment, especially in the BM soil. Therefore, although bioaugmentation of introduced microbial consortium increased significantly the biodegradation of PAHs in aged contaminated soil with low PAH concentration, the creation of optimum of the environmental situation might be the best way to use bioremediation successfully in the field.

  4. Culture-Dependent and -Independent Methods Capture Different Microbial Community Fractions in Hydrocarbon-Contaminated Soils

    Science.gov (United States)

    Stefani, Franck O. P.; Bell, Terrence H.; Marchand, Charlotte; de la Providencia, Ivan E.; El Yassimi, Abdel; St-Arnaud, Marc; Hijri, Mohamed

    2015-01-01

    Bioremediation is a cost-effective and sustainable approach for treating polluted soils, but our ability to improve on current bioremediation strategies depends on our ability to isolate microorganisms from these soils. Although culturing is widely used in bioremediation research and applications, it is unknown whether the composition of cultured isolates closely mirrors the indigenous microbial community from contaminated soils. To assess this, we paired culture-independent (454-pyrosequencing of total soil DNA) with culture-dependent (isolation using seven different growth media) techniques to analyse the bacterial and fungal communities from hydrocarbon-contaminated soils. Although bacterial and fungal rarefaction curves were saturated for both methods, only 2.4% and 8.2% of the bacterial and fungal OTUs, respectively, were shared between datasets. Isolated taxa increased the total recovered species richness by only 2% for bacteria and 5% for fungi. Interestingly, none of the bacteria that we isolated were representative of the major bacterial OTUs recovered by 454-pyrosequencing. Isolation of fungi was moderately more effective at capturing the dominant OTUs observed by culture-independent analysis, as 3 of 31 cultured fungal strains ranked among the 20 most abundant fungal OTUs in the 454-pyrosequencing dataset. This study is one of the most comprehensive comparisons of microbial communities from hydrocarbon-contaminated soils using both isolation and high-throughput sequencing methods. PMID:26053848

  5. Culture-Dependent and -Independent Methods Capture Different Microbial Community Fractions in Hydrocarbon-Contaminated Soils.

    Directory of Open Access Journals (Sweden)

    Franck O P Stefani

    Full Text Available Bioremediation is a cost-effective and sustainable approach for treating polluted soils, but our ability to improve on current bioremediation strategies depends on our ability to isolate microorganisms from these soils. Although culturing is widely used in bioremediation research and applications, it is unknown whether the composition of cultured isolates closely mirrors the indigenous microbial community from contaminated soils. To assess this, we paired culture-independent (454-pyrosequencing of total soil DNA with culture-dependent (isolation using seven different growth media techniques to analyse the bacterial and fungal communities from hydrocarbon-contaminated soils. Although bacterial and fungal rarefaction curves were saturated for both methods, only 2.4% and 8.2% of the bacterial and fungal OTUs, respectively, were shared between datasets. Isolated taxa increased the total recovered species richness by only 2% for bacteria and 5% for fungi. Interestingly, none of the bacteria that we isolated were representative of the major bacterial OTUs recovered by 454-pyrosequencing. Isolation of fungi was moderately more effective at capturing the dominant OTUs observed by culture-independent analysis, as 3 of 31 cultured fungal strains ranked among the 20 most abundant fungal OTUs in the 454-pyrosequencing dataset. This study is one of the most comprehensive comparisons of microbial communities from hydrocarbon-contaminated soils using both isolation and high-throughput sequencing methods.

  6. Microbial population, chemical composition and silage fermentation of cassava residues.

    Science.gov (United States)

    Napasirth, Viengsakoun; Napasirth, Pattaya; Sulinthone, Tue; Phommachanh, Kham; Cai, Yimin

    2015-09-01

    In order to effectively use the cassava (Manihot esculenta Crantz) residues, including cassava leaves, peel and pulp for livestock diets, the chemical and microbiological composition, silage preparation and the effects of lactic acid bacteria (LAB) inoculants on silage fermentation of cassava residues were studied. These residues contained 10(4) to 10(5) LAB and yeasts, 10(3) to 10(4) coliform bacteria and 10(4) aerobic bacteria in colony forming units (cfu) on a fresh matter (FM) basis. The molds were consistently at or below the detectable level (10(2) cfu of FM) in three kinds of cassava residues. Dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) content of cassava residues were 17.50-30.95%, 1.30-16.41% and 25.40-52.90% on a DM basis, respectively. The silage treatments were designed as control silage without additive (CO) or with LAB inoculants Chikuso-1 (CH, Lactobacillus plantarum) and Snow Lacto (SN, Lactobacillus rhamnosus) at a rate of 5 mg/kg of FM basis. All silages were well preserved with a low pH (below 4.0) value and when cassava residues silage treated with inoculants CH and SN improved fermentation quality with a lower pH, butyric acid and higher lactic acid than control silage.

  7. Hydrocarbon Degradation Pathways used by Coastal Sediment Microbial Communities exposed to Crude Oil

    Science.gov (United States)

    Spaulding-Astudillo, F.; Sharrar, A.; Orcutt, B.

    2016-02-01

    The site-specific microbial community response to crude oil exposure in marine environments is not well described. Moreover, the abundance of genes implicated in long-chain alkane (LCA) and polycyclic aromatic hydrocarbon (PAH) degradation are not well understood. Coastal sediments from the Beaufort Sea, Gulf of Alaska, and Portland Harbor were treated with crude oil and incubated aerobically. Deep-sea sediments from the Gulf of Mexico were treated with the same crude oil and anaerobically incubated in situ for five months before recovery. Cycloclasticus, a known hydrocarbon-degrader, was abundant in all oiled, aerobic samples regardless of temperature, demonstrating a generalist oil-response strategy. Other hydrocarbon degrading bacteria showed differential response to either site or temperature. Primers for alkB, assA, bssA, and ncr, catabolic gene markers for aerobic LCA degradation, anaerobic LCA degradation, anaerobic LCA & PAH degradation, and anaerobic PAH degradation, respectively, were found in literature and tested on DNA extracts in a QPCR-based assay. Gene abundance was site and condition variable.

  8. BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS.

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Whitney Jones, W; Charles Milliken, C

    2008-05-27

    BioTiger{trademark} is a unique microbial consortia that resulted from over 8 years of extensive microbiology screening and characterization of samples collected from a century-old Polish waste lagoon. BioTiger{trademark} shows rapid and complete degradation of aliphatic and aromatic hydrocarbons, produces novel surfactants, is tolerant of both chemical and metal toxicity and shows good activity at temperature and pH extremes. Although originally developed and used by the U.S. Department of Energy for bioremediation of oil-contaminated soils, recent efforts have proven that BioTiger{trademark} can also be used to increase hydrocarbon recovery from oil sands. This enhanced ex situ oil recovery process utilizes BioTiger{trademark} to optimize bitumen separation. A floatation test protocol with oil sands from Ft. McMurray, Canada was used for the BioTiger{trademark} evaluation. A comparison of hot water extraction/floatation test of the oil sands performed with BioTiger{trademark} demonstrated a 50% improvement in separation as measured by gravimetric analysis in 4 h and a five-fold increase at 25 hr. Since BioTiger{trademark} performs well at high temperatures and process engineering can enhance and sustain metabolic activity, it can be applied to enhance recovery of hydrocarbons from oil sands or other complex recalcitrant matrices.

  9. Genotypic and Phenotypic Responses of a Riverine Microbial Community to Polycyclic Aromatic Hydrocarbon Contamination

    Science.gov (United States)

    Langworthy, Donald E.; Stapleton, Raymond D.; Sayler, Gary S.; Findlay, Robert H.

    1998-01-01

    The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated (22 to 217 μg g [dry weight] of sediment−1) levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site was the Little Scioto River, a highly impacted, channelized riverine system located in central Ohio. This study site is a unique lotic system, with all sampling stations having similar flow and sediment characteristics both upstream and downstream from the source of contamination. These characteristics allowed for the specific analysis of PAH impact on the microbial community. PAH concentrations in impacted sediments ranged from 22 to 217 μg g (dry weight) of sediment−1, while PAH concentrations in ambient sediments ranged from below detection levels to 1.5 μg g (dry weight) of sediment−1. Total microbial biomass measured by phospholipid phosphate (PLP) analysis ranged from 95 to 345 nmol of PLP g (dry weight) of sediment−1. Nucleic acid analysis showed the presence of PAH-degradative genes at all sites, although observed frequencies were typically higher at contaminated sites. Principal component analysis of PLFA profiles indicated that moderate to high PAH concentrations altered microbial community structure and that seasonal changes were comparable in magnitude to the effects of PAH pollution. These data indicate that this community responded to PAH contamination at both the phenotypic and the genotypic level. PMID:9726892

  10. The lack of microbial degradation of polycyclic aromatic hydrocarbons from coal-rich soils.

    Science.gov (United States)

    Achten, Christine; Cheng, Shubo; Straub, Kristina L; Hofmann, Thilo

    2011-02-01

    Analytical techniques used to assess the environmental risk of contamination from polycyclic aromatic hydrocarbons (PAHs) typically consider only abiotic sample parameters. Supercritical fluid extraction and sorption enthalpy experiments previously suggested slow desorption rates for PAH compounds in two coal-contaminated floodplain soils. In this study, the actual PAH availability for aerobic soil microorganisms was tested in two series of soil-slurry experiments. The experimental conditions supported microbial degradation of phenanthrene if it was weakly sorbed onto silica gel. Native coals and coal-derived particles in two soils effectively acted as very strong sorbents and prevented microbial PAH degradation. The long history of PAH exposure and degree of coal contamination apparently had no influence on the capability of the microbial soil community to overcome constraints of PAH availability. Within the context of the experimental conditions and the compounds chosen, our results confirm that coal-bound PAHs are not bioavailable and hence of low environmental concern. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Oxidation of polycyclic aromatic hydrocarbons using partially purified laccase from residual compost of agaricus bisporus

    Energy Technology Data Exchange (ETDEWEB)

    Mayolo-Deloisa, K. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Machin-Ramirez, C. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Faculty of Chemical Sciences and Engineering, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Rito-Palomares, M. [Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Trejo-Hernandez, M.R. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico)

    2011-08-15

    Laccase partially purified from residual compost of Agaricus bisporus by an aqueous two-phase system (Lac ATPS) was used in degrading polycyclic aromatic hydrocarbons: fluorene (Flu), phenanthrene (Phe), anthracene (Ant), benzo[a]pyrene (BaP), and benzo[a]anthracene (BaA). The capacity of the enzyme to oxidize polyaromatic compounds was compared to that of the crude laccase extract (CE). After treatment of 72 h, Lac ATPS and CE were not capable of oxidizing Flu and Phe, while Ant, BaP, and BaA were oxidized, resulting in percentages of oxidation of 11.2 {+-} 1, 26 {+-} 2, and 11.7 {+-} 4 % with CE, respectively. When Lac ATPS was used, the following percentages of oxidation were obtained: 11.4 {+-} 3 % for Ant, 34 {+-} 0.1 % for BaP, and 13.6 {+-} 2 % for BaA. The results reported here demonstrate the potential application of Lac ATPS for the oxidation of polycyclic aromatic hydrocarbons. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Response of core microbial consortia to hydrocarbon contaminations in coastal sediment habitats

    Directory of Open Access Journals (Sweden)

    Mathilde Jeanbille

    2016-10-01

    Full Text Available Traditionally, microbial surveys investigating the effect of chronic anthropogenic pressure such as polyaromatic hydrocarbons (PAHs contaminations consider just the alpha and beta diversity and ignore the interactions among the different taxa forming the microbial community. Here, we investigated the ecological relationships between the three domains of life (i.e. Bacteria, Archaea and Eukarya using 454 pyrosequencing data of the 16S rRNA and 18S rRNA genes from chronically impacted and pristine sediments, along the coasts of the Mediterranean Sea (Gulf of Lion, Vermillion coast, Corsica, Bizerte lagoon and Lebanon and the French Atlantic Ocean (Bay of Biscay and English Channel. Our approach provided a robust ecological framework for the partition of the taxa abundance distribution into 859 core OTUs and 6629 satellite OTUs. OTUs forming the core microbial community showed the highest sensitivity to changes in environmental and contaminant variations, with salinity, latitude, temperature, particle size distribution, total organic carbon (TOC and PAH concentrations as main drivers of community assembly. The core communities were dominated by Gammaproteobacteria and Deltaproteobacteria for Bacteria, by Thaumarchaeota, Bathyarchaeota and Thermoplasmata for Archaea and Metazoa and Dinoflagellata for Eukarya. In order to find associations among microorganisms, we generated a co-occurrence network in which PAHs were found to impact significantly the potential predator – prey relationship in one microbial consortium composed of ciliates and Actinobacteria. Comparison of network topological properties between contaminated and non-contaminated samples showed substantial differences in the structure of the network and indicated a higher vulnerability to environmental perturbations in the contaminated sediments.

  13. Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs

    KAUST Repository

    Cerezo, Maria Isabel

    2015-11-01

    One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers\\' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.

  14. Improved microbial screning assay for the detection of quinolone residues in poultry and eggs

    NARCIS (Netherlands)

    Pikkemaat, M.G.; Mulder, P.P.J.; Elferink, J.W.A.; Cocq, A.; Nielen, M.W.F.; Egmond, van H.J.

    2007-01-01

    An improved microbiological screening assay is reported for the detection of quinolone residues in poultry muscle and eggs. The method was validated using fortified tissue samples and is the first microbial assay to effectively detect enrofloxacin, difloxacin, danofloxacin, as well as flumequine and

  15. Multi-Year Analysis of Hydrocarbon-Degrading Microbial Communities at the Petroleum-Contaminated site in Bemidji, Minn.

    Science.gov (United States)

    Rossbach, S.; Beaver, C. L.; Atekwana, E. A.; Enright, A. M.; Ntarlagiannis, D.; Lund, A.; Slater, L. D.

    2016-12-01

    The purpose of this study was the synchronized geophysical and microbiological analysis of the subsurface petroleum spill in Bemidji, MN. Initially, the center of the free-phase hydrocarbon plume exhibited high magnetic susceptibility (MS) around the water table, however, the MS values decreased in subsequent years. To monitor the composition of the microbial community over time, sediment cores were collected in five consecutive years from the free-phase petroleum plume. Assisted by the sample-freezing drive shoe, continuous cores were collected that stretched below the water table. High-throughput DNA sequencing based on the 16S rRNA gene was applied to closely-spaced samples from the cores, and MS was measured in situ and from the cores. Exactly around the fluctuating water table, where the magnetic susceptibility anomaly had been measured, a methanogenic microbial community was found. The main microbial populations in this community were, besides the hydrocarbon-degrading Firmicutes, the syntrophic propionate oxidizer Smithella and the methanogenic Archaeon Methanoregula. Both genera, Smithella and Methanoregula, were consistently present in samples from all five years, and seem to follow the fluctuating water table. A high water table coincided with high MS and the presence of magnetite, whereas a lower water table may have resulted in the oxidation of magnetite resulting in the measurements of lower MS. Augmented by laboratory analyses of iron oxide minerals and microcosm studies, we are evaluating how certain microbial populations influence the geophysical characteristics of the surrounding sediments during microbial hydrocarbon degradation.

  16. Investigation of petroleum residues and microbial PLFA in Barataria Bay sediments one year after the Deepwater Horizon oil spill

    Science.gov (United States)

    Clay, S.; Zimmerman, A. R.; Mahmoudi, N.; Silliman, B. R.; Slater, G. F.

    2012-12-01

    The Deepwater Horizon spill released crude oil into the Gulf of Mexico over a period of 3 months in 2010. Barataria Bay, Louisiana was among the most heavily impacted and extensively oil-contaminated coastlines. Studies conducted in the marshes show significant ecological and geologic effects from oil residues that reached the bay. Observation of the presence of an oil sheen associated with sediment disturbance raised the question as to whether petroleum residues were also present in the sediments of Barataria Bay. In order to address this question, six sediment cores were collected from non-oiled (#1 & 2) and oiled (#3-6) portions of Barataria Bay approximately one year after the Deepwater Horizon oil spill. Concentrations of n-alkanes, unresolved complex material (UCM) and polycyclic aromatic hydrocarbon (PAH) were determined in these upper sediments. In addition, concentrations of phospholipid fatty acids (PLFA) were determined to assess variations in microbial community abundance. Alkane concentrations ranged from 134 to 747 ng/g with chain lengths from C12 to C35. Most cores showed an odd over even preference (carbon preference index of 1.2 to 4.3) with highest concentrations of long chain compounds between C24 and C35 (average chain length 29 to 39), consistent with a terrestrial carbon source such as plant waxes. Core #6 however, in the southwest portion of the bay, had the lowest concentrations of alkanes, and shorter n-alkane chain lengths overall. Despite this difference, the core maintains a relatively high carbon preference index and average chain length compared to that which would be expected from oil contaminated sediments. Measured PAH concentrations were highly variable ranging from undetectable to 436 ng/g. These values are several orders of magnitude lower than what is generally seen in highly contaminated sediments. Further, UCM concentrations were negligible in the cores from the oiled regions. These findings suggest only a minimal presence of

  17. Temperature and injection water source influence microbial community structure in four Alaskan North Slope hydrocarbon reservoirs.

    Directory of Open Access Journals (Sweden)

    Yvette Marisa Piceno

    2014-08-01

    Full Text Available A fundamental knowledge of microbial community structure in petroleum reservoirs can improve predictive modeling of these environments. We used hydrocarbon profiles, stable isotopes, and high-density DNA microarray analysis to characterize microbial communities in produced water from four Alaska North Slope hydrocarbon reservoirs. Produced fluids from Schrader Bluff (24-27°C, Kuparuk (47-70°C, Sag River (80°C, and Ivishak (80-83°C reservoirs were collected, with paired soured/non-soured wells sampled from Kuparuk and Ivishak. Chemical and stable isotope data suggested Schrader Bluff had substantial biogenic methane, whereas methane was mostly thermogenic in deeper reservoirs. Acetoclastic methanogens (Methanosaeta were most prominent in Schrader Bluff samples, and the combined δD and δ13C values of methane also indicated acetoclastic methanogenesis could be a primary route for biogenic methane. Conversely, hydrogenotrophic methanogens (e.g., Methanobacteriaceae and sulfide-producing Archaeoglobus and Thermococcus were more prominent in Kuparuk samples. Sulfide-producing microbes were detected in all reservoirs, uncoupled from souring status (e.g., the non-soured Kuparuk samples had higher relative abundances of many sulfate-reducers compared to the soured sample, suggesting sulfate-reducers may be living fermentatively/syntrophically when sulfate is limited. Sulfate abundance via long-term seawater injection resulted in greater relative abundances of Desulfonauticus, Desulfomicrobium, and Desulfuromonas in the soured Ivishak well compared to the non-soured well. In the non-soured Ivishak sample, several taxa affiliated with Thermoanaerobacter and Halomonas predominated. Archaea were not detected in the deepest reservoirs. Functional group taxa differed in relative abundance among reservoirs, likely reflecting differing thermal and/or geochemical influences.

  18. Polycyclic Aromatic Hydrocarbon Residues in Serum Samples of Autopsied Individuals from Tennessee

    Directory of Open Access Journals (Sweden)

    Aramandla Ramesh

    2014-12-01

    Full Text Available This study reports the concentrations of Polycyclic Aromatic Hydrocarbons (PAHs in human blood sera samples (n = 650 obtained at autopsy from individuals who died of drug abuse, alcohol toxicity, homicide, suicide and other unknown causes. The analyzed samples from decedents revealed the presence of PAHs of which B(aP was the most predominant one, followed by benzo(bfluoranthene and benzo(kfluoranthene. The other PAHs detected sporadically and measured were benzo(g,h,iperylene, acenaphthene, anthracene, phenanthrene, and fluoranthene The mean concentrations of PAHs were greater in the twenties to fifties age groups compared to others. The PAH residue levels detected were high in African Americans compared to Caucasians, Asians, and Hispanics. It appears that environmental exposure, dietary intake and in some cases occupational exposure may have contributed to the PAH body burden. While the PAH residue concentrations measured fall within the range of those reported for healthy adults elsewhere, in isolated cases, the concentrations detected were high, calling the need for a reduction in PAH emissions and human biomonitoring studies for purposes of risk assessment.

  19. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico native coastal microbial communities after the Deepwater Horizon oil spill.

    Science.gov (United States)

    Kappell, Anthony D; Wei, Yin; Newton, Ryan J; Van Nostrand, Joy D; Zhou, Jizhong; McLellan, Sandra L; Hristova, Krassimira R

    2014-01-01

    The Deepwater Horizon (DWH) blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs) to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including polycyclic aromatic hydrocarbons (PAHs), were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are

  20. Comparison of indigenous and exogenous microbial populations during slurry phase biodegradation of long-term hydrocarbon-contaminated soil.

    Science.gov (United States)

    Aburto-Medina, Arturo; Adetutu, Eric M; Aleer, Sam; Weber, John; Patil, Sayali S; Sheppard, Petra J; Ball, Andrew S; Juhasz, Albert L

    2012-11-01

    In this study, a number of slurry-phase strategies were trialled over a 42 day period in order to determine the efficacy of bioremediation for long-term hydrocarbon-contaminated soil (145 g kg(-1) C(10)-C(40)). The addition of activated sludge and nutrients to slurries (bioaugmentation) resulted in enhanced hydrocarbon removal (51.6 ± 8.5 %) compared to treatments receiving only nutrients (enhanced natural attenuation [ENA]; 41.3 ± 6.4 %) or no amendments (natural attenuation; no significant hydrocarbon removal, P hydrocarbons in ENA slurries. Microbial diversity in slurries was monitored using DGGE with dominant bands excised and sequenced for identification. Applying the different bioremediation strategies resulted in the formation of four distinct community clusters associated with the activated sludge (inoculum), bioaugmentation strategy at day 0, bioaugmentation strategy at weeks 2-6 and slurries with autoclaved sludge and nutrient additions (bioaugmentation negative control). While hydrocarbon-degrading bacteria genera (e.g. Aquabacterium and Haliscomenobacter) were associated with the hydrocarbon-contaminated soil, bioaugmentation of soil slurries with activated sludge resulted in the introduction of bacteria associated with hydrocarbon degradation (Burkholderiales order and Klebsiella genera) which presumably contributed to the enhanced efficacy for this slurry strategy.

  1. Microbial Diversity and Bioremediation of a Hydrocarbon-Contaminated Aquifer (Vega Baja, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Arturo A. Massol-Deyá

    2006-09-01

    Full Text Available Hydrocarbon contamination of groundwater resources has become a major environmental and human health concern in many parts of the world. Our objectives were to employ both culture and culture-independent techniques to characterize the dynamics of microbial community structure within a fluidized bed reactor used to bioremediate a diesel-contaminated groundwater in a tropical environment. Under normal operating conditions, 97 to 99% of total hydrocarbons were removed with only 14 min hydraulic retention time. Over 25 different cultures were isolated from the treatment unit (96% which utilized diesel constituents as sole carbon source. Approximately 20% of the isolates were also capable of complete denitrification to nitrogen gas. Sequence analysis of 16S rDNA demonstrated ample diversity with most belonging to the ∝, β and γ subdivision of the Proteobacteria, Bacilli, and Actinobacteria groups. Moreover, the genetic constitution of the microbial community was examined at multiple time points with a Functional Gene Array (FGA containing over 12,000 probes for genes involved in organic degradation and major biogeochemical cycles. Total community DNA was extracted and amplified using an isothermal φ29 polymerase-based technique, labeled with Cy5 dye, and hybridized to the arrays in 50% formimide overnight at 50°C. Cluster analysis revealed comparable profiles over the course of treatment suggesting the early selection of a very stable microbial community. A total of 270 genes for organic contaminant degradation (including naphthalene, toluene [aerobic and anaerobic], octane, biphenyl, pyrene, xylene, phenanthrene, and benzene; and 333 genes involved in metabolic activities (nitrite and nitrous oxide reductases [nirS, nirK, and nosZ], dissimilatory sulfite reductases [dsrAB], potential metal reducing C-type cytochromes, and methane monooxygenase [pmoA] were repeatedly detected. Genes for degradation of MTBE

  2. Microbial production of aliphatic hydrocarbons. Progress report, February 1, 1979-September 30, 1979. [Optimization for commercial oily hydrocarbon production

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T G

    1979-09-01

    The neutral lipids of nine species of methanogenic bacteria, two thermoacidophiles, two alkalinophiles and 20 algal samples were analyzed. The major components were C/sub 30/, C/sub 25/, and/or C/sub 20/ acyclic isoprenoid hydrocarbons with a continuous range of hydroisoprenoid homologues. The range or acyclic isoprenoids detected were from C/sub 14/ to C/sub 30/. The neutral lipid composition from these bacteria resembles the isoprenoid distribution isolated from ancient sediments and petroleum. Therefore, these findings may have major implications to biological and biogeochemical evolution. In this connection, samples and cores from ancient sediments and future fossil fuel source beds are being analyzed for these neutral lipids as well as the more polar isopranyl glycerol-ether lipids. The derivation of fossil fuels and the biomass accumulations are the focal points of this phase of the study. Ancient and recent sediments, future source beds, and local esturaries are being enriched for microorganisms to establish a range and capability profile for hydrocarbon production. Only a relatively small percent of the microorganisms isolated demonstrated the ability to synthesize hydrocarbons; however, one particular algal isolate demonstrated that it can synthesize hydrocarbons while in a green physiological stage. Greater production is expected in the brown phase of growth. Hydrocarbon biosynthesis studies were conducted in an attempt to better understand the conditions required to maximize hydrocarbon production. The program involved physical and chemical parameters as well as assays of specifically labelled precusors with a cell free enzyme system to measure their conversions to hydrocarbons. The results have indicated a complex one enzyme system is involved in condensation and reduction of two fatty acids into hydrocarbons.

  3. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico coastal microbial communities after the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Anthony D. Kappell

    2014-05-01

    Full Text Available The Deepwater Horizon (DWH blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including PAHs, were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are primed for PAH

  4. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    hydrocarbon polluted sediments and water .... ecosystem may result in selective increase or decrease in microbial population (Okpokwasili ... been implicated in degradation of hydrocarbons such as crude oil, polyaromatic hydrocarbons and.

  5. Microbial diversity in a hydrocarbon- and chlorinated-solvent- contaminated aquifer undergoing intrinsic bioremediation

    Science.gov (United States)

    Dojka, M.A.; Hugenholtz, P.; Haack, S.K.; Pace, N.R.

    1998-01-01

    A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons (mainly jet fuel) and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes were amplified directly from aquifer material DNA by PCR with universally conserved or Bacteria- or Archaea-specific primers and were cloned. A total of 812 clones were screened by restriction fragment length polymorphisms (RFLP), approximately 50% of which were unique. All RFLP types that occurred more than once in the libraries, as well as many of the unique types, were sequenced. A total of 104 (94 bacterial and 10 archaeal) sequence types were determined. Of the 94 bacterial sequence types, 10 have no phylogenetic association with known taxonomic divisions and are phylogenetically grouped in six novel division level groups (candidate divisions WS1 to WS6); 21 belong to four recently described candidate divisions with no cultivated representatives (OPS, OP8, OP10, and OP11); and 63 are phylogenetically associated with 10 well-recognized divisions. The physiology of two particularly abundant sequence types obtained from the methanogenic zone could be inferred from their phylogenetic association with groups of microorganisms with a consistent phenotype. One of these sequence types is associated with the genus Syntrophus; Syntrophus spp. produce energy from the anaerobic oxidation of organic acids, with the production of acetate and hydrogen. The organism represented by the other sequence type is closely related to Methanosaeta spp., which are known to be capable of energy generation only through aceticlastic methanogenesis. We hypothesize, therefore, that the terminal step of hydrocarbon degradation in the methanogenic zone of the aquifer is aceticlastic methanogenesis and

  6. The total and freely dissolved polycyclic aromatic hydrocarbons content in residues from biogas production.

    Science.gov (United States)

    Stefaniuk, Magdalena; Oleszczuk, Patryk

    2016-01-01

    In the situation of increasing agricultural utilization of residues from biogas production (RBP) it is important to determine the concentration of contaminants, which could occur in these materials. The group of contaminants that requires special attention are polycyclic aromatic hydrocarbons (PAH). The objective of the study was to determine the total and freely dissolved (Cfree) of PAHs in RBP from 6 different biogas plants operating under various temperature conditions and without or with the separation into the solid and liquid fractions. The freely dissolved PAHs were determined using polyoxymethylene (POM method). The total content of the Σ16 PAHs in RBP varied from 449 to 6147 μg/kgdw, while that of Cfree PAHs was at the level from 57 to 653 ng/L. No significant differences were noted in the content of the Σ16 PAHs (total) between the solid and the liquid fractions. This indicates that in the course of the separation, the PAHs are distributed proportionally between the fractions. However in the case of Cfree, PAHs content in the solid fraction was over twice as high as in the liquid fraction. This was probably due to the greater affinity of the particles present in the liquid fraction to the analysed PAHs than to the particles of the solid fraction. Higher affinity to liquid fraction was also confirmed by the distribution coefficients KTOC determined on the basis of Cfree.

  7. Activity and functional diversity of microbial communities in long-term hydrocarbon and heavy metal contaminated soils

    Directory of Open Access Journals (Sweden)

    Markowicz Anna

    2016-12-01

    Full Text Available The impacts of long-term polycyclic aromatic hydrocarbons (PAHs and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni, moisture and conductivity than by PAHs.

  8. Microbial responses to polycyclic aromatic hydrocarbon contamination in temporary river sediments: Experimental insights.

    Science.gov (United States)

    Zoppini, Annamaria; Ademollo, Nicoletta; Amalfitano, Stefano; Capri, Silvio; Casella, Patrizia; Fazi, Stefano; Marxsen, Juergen; Patrolecco, Luisa

    2016-01-15

    Temporary rivers are characterized by dry-wet phases and represent an important water resource in semi-arid regions worldwide. The fate and effect of contaminants have not been firmly established in temporary rivers such as in other aquatic environments. In this study, we assessed the effects of sediment amendment with Polycyclic Aromatic Hydrocarbons (PAHs) on benthic microbial communities. Experimental microcosms containing natural (Control) and amended sediments (2 and 20 mg PAHs kg(-1) were incubated for 28 days. The PAH concentrations in sediments were monitored weekly together with microbial community structural (biomass and phylogenetic composition by TGGE and CARD-FISH) and functional parameters (ATP concentration, community respiration rate, bacterial carbon production rate, extracellular enzyme activities). The concentration of the PAH isomers did not change significantly with the exception of phenanthrene. No changes were observed in the TGGE profiles, whereas the occurrence of Alpha- and Beta-Proteobacteria was significantly affected by the treatments. In the amended sediments, the rates of carbon production were stimulated together with aminopeptidase enzyme activity. The community respiration rates showed values significantly lower than the Control after 1 day from the amendment then recovering the Control values during the incubation. A negative trend between the respiration rates and ATP concentration was observed only in the amended sediments. This result indicates a potential toxic effect on the oxidative phosphorylation processes. The impoverishment of the energetic resources that follows the PAH impact may act as a domino on the flux of energy from prokaryotes to the upper level of the trophic chain, with the potential to alter the temporary river functioning.

  9. Microbial degradation of street dust polycyclic aromatic hydrocarbons in microcosms simulating diffuse pollution of urban soil.

    Science.gov (United States)

    Johnsen, Anders R; de Lipthay, Julia R; Sørensen, Søren J; Ekelund, Flemming; Christensen, Peter; Andersen, Ole; Karlson, Ulrich; Jacobsen, Carsten S

    2006-03-01

    Diffuse pollution with polycyclic aromatic hydrocarbons (PAHs) of topsoil in urban regions has caused increasing concerns in recent years. We simulated diffuse pollution of soil in microcosms by spiking sandy topsoil (A-horizon) and coarse, mineral subsoil (C-horizon) with street dust (PM63) isolated from municipal street sweepings from central Copenhagen. The microbial communities adapted to PAH degradation in microcosms spiked with street dust in both A-horizon and C-horizon soils, in spite of low PAH-concentrations. The increased potential for PAH degradation was demonstrated on several levels: by slowly diminishing PAH-concentrations, increased mineralization of 14C-PAHs, increasing numbers of PAH degraders and increased prevalence of nah and pdo1 PAH degradation genes, i.e. the microbial communities quickly adapted to PAH degradation. Three- and 4-ring PAHs from the street dust were biodegraded to some extent (10-20%), but 5- and 6-ring PAHs were not biodegraded in spite of frequent soil mixing and high PAH degradation potentials. In addition to biodegradation, leaching of 2-, 3- and 4-ring PAHs from the A-horizon to the C-horizon seems to reduce PAH-levels in surface soil. Over time, levels of 2-, 3- and 4-ring PAHs in surface soil may reach equilibrium between input and the combination of biodegradation and leaching. However, levels of the environmentally critical 5- and 6-ring PAHs will probably continue to rise. We presume that sorption to black carbon particles is responsible for the persistence and low bioaccessibility of 5- and 6-ring PAHs in diffusely polluted soil.

  10. Albendazole residues in goat's milk: Interferences in microbial inhibitor tests used to detect antibiotics in milk

    Directory of Open Access Journals (Sweden)

    Tamara Romero

    2017-04-01

    Full Text Available Albendazole (ABZ residues in goat's milk and their effect on the response of microbial inhibitor tests used for screening antibiotics were evaluated. A total of 18 Murciano-Granadina goats were treated with ABZ and individually milked once a day over a 7-day period. ABZ quantification was performed by high performance liquid chromatography. The ABZ parent drug was not detected. The maximum concentration of its metabolites (ABZ sulfoxide, ABZ sulfone, and ABZ 2-aminosulfone was reached on the 1st day post treatment (260.0 ± 70.1 μg/kg, 112.8 ± 28.7 μg/kg, 152.0 ± 23.6 μg/kg, respectively, decreasing to lower than the maximum residue limit (MRL, 100 μg/kg on the 3rd day post treatment. Milk samples were also analyzed by microbial tests [Brilliant Black Reduction Test (BRT MRL, Delvotest SP-NT MCS and Eclipse 100], and only one positive result was found for Delvotest SP-NT MCS and Eclipse 100. However, a high occurrence of positive outcomes was obtained for BRT MRL during 6 days post treatment, whereas ABZ residues were not detected from the 4th day post administration, suggesting that factors other than the antiparasitic agent might affect the microbial test response.

  11. Stabilization of diverse microbial residues in California and Puerto Rico Forest Soils

    Science.gov (United States)

    Throckmorton, H.; Bird, J.; Dane, L.; Firestone, M.; Horwath, W.

    2012-04-01

    The contribution of C from the turnover of diverse microorganisms to stable C pools remains poorly understood. This study follows the turnover of 13C labeled nonliving residues from diverse microbial groups in situ in a temperate forest in California (CA) and a tropical forest in Puerto Rico (PR), during 5 sampling points per site- over a 3 and 2 year period, respectively. Microbial groups include fungi, actinomycetes, Gm(+) bacteria, and Gm(-) bacteria, isolated from CA and PR soils to obtain temperate and tropical isolates. Results indicated that, despite unique biochemical makeup among groups as determined by Py-GC-MS, microbial residues exhibited similar mean residence times (MRTs) within each site. A density fractionation approach isolated: a "light fraction" (LF), non-mineral aggregate "occluded fraction" (OF), and a "mineral bound fraction" (MF). Microbial C inputs were more stable in the OF and MF than the LF throughout the course of the study at both sites. There were no significant differences in 13C recovery among microbes in any PR fractions, despite minor differences in overall MRTs. In CA, there were some significant differences in 13C recovery among microbial inputs in the LF and OF, which related to 13C recoveries in whole soils. In the CA MF, microbial recoveries did not differ, and low variability among treatments was observed. Results support increased protection of microbial C via association with the mineral matrix; however, differential sorption of some microbial isolates over others was not observed. Overall results suggest that inherent recalcitrance of microbial residues may be more important to determining its stability in CA soils when it is 1) unassociated with the mineral matrix (LF); or 2) occluded within aggregates; compared with that strongly associated with mineral surfaces (MF). The overall composition of SOM in fractions also differed, with a greater concentration of benzene and N compounds in the MF; lignin and phenol compounds

  12. Indigenous microbial capability in solid manure residues to start-up solid-phase anaerobic digesters.

    Science.gov (United States)

    Yap, S D; Astals, S; Jensen, P D; Batstone, D J; Tait, S

    2017-06-01

    Batch solid-phase anaerobic digestion is a technology for sustainable on-farm treatment of solid residues, but is an emerging technology that is yet to be optimised with respect to start-up and inoculation. In the present study, spent bedding from two piggeries (site A and B) were batch digested at total solids (TS) concentration of 5, 10 and 20% at mesophilic (37°C) and thermophilic (55°C) temperatures, without adding an external inoculum. The results showed that the indigenous microbial community present in spent bedding was able to recover the full methane potential of the bedding (140±5 and 227±6L CH4 kgVSfed(-1) for site A and B, respectively), but longer treatment times were required than for digestion with an added external inoculum. Nonetheless, at high solid loadings (i.e. TS level>10%), the digestion performance was affected by chemical inhibition due to ammonia and/or humic acid. Thermophilic temperatures did not influence digestion performance but did increase start-up failure risk. Further, inoculation of residues from the batch digestion to subsequent batch enhanced start-up and achieved full methane potential recovery of the bedding. Inoculation with liquid residue (leachate) was preferred over a solid residue, to preserve treatment capacity for fresh substrate. Overall, the study highlighted that indigenous microbial community in the solid manure residue was capable of recovering full methane potential and that solid-phase digestion was ultimately limited by chemical inhibition rather than lack of suitable microbial community. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The impact of long-term hydrocarbon exposure on the structure, activity, and biogeochemical functioning of microbial mats.

    Science.gov (United States)

    Aubé, Johanne; Senin, Pavel; Pringault, Olivier; Bonin, Patricia; Deflandre, Bruno; Bouchez, Olivier; Bru, Noëlle; Biritxinaga-Etchart, Edurne; Klopp, Christophe; Guyoneaud, Rémy; Goñi-Urriza, Marisol

    2016-10-15

    Photosynthetic microbial mats are metabolically structured systems driven by solar light. They are ubiquitous and can grow in hydrocarbon-polluted sites. Our aim is to determine the impact of chronic hydrocarbon contamination on the structure, activity, and functioning of a microbial mat. We compared it to an uncontaminated mat harboring similar geochemical characteristics. The mats were sampled in spring and fall for 2years. Seasonal variations were observed for the reference mat: sulfur cycle-related bacteria dominated spring samples, while Cyanobacteria dominated in autumn. The contaminated mat showed minor seasonal variation; a progressive increase of Cyanobacteria was noticed, indicating a perturbation of the classical seasonal behavior. Hydrocarbon content was the main factor explaining the differences in the microbial community structure; however, hydrocarbonoclastic bacteria were among rare or transient Operational Taxonomic Units (OTUs) in the contaminated mat. We suggest that in long-term contaminated systems, hydrocarbonoclastic bacteria cannot be considered a sentinel of contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Using sediment microbial fuel cells (SMFCs) for bioremediation of polycyclic aromatic hydrocarbons (PAHs).

    Science.gov (United States)

    Sherafatmand, Mohammad; Ng, How Yong

    2015-11-01

    In this study, a sediment microbial fuel cell (SMFC) was explored to bioremediate polycyclic aromatic hydrocarbons (PAHs) in water originated from soil. The results showed consistent power generations of 6.02±0.34 and 3.63±0.37 mW/m(2) under an external resistance of 1500 Ω by the aerobic and anaerobic SMFC, respectively. Although the power generations were low, they had relatively low internal resistances (i.e., 436.6±69.4 and 522.1±1.8 Ω for the aerobic and anaerobic SMFC, respectively) in comparison with the literature. Nevertheless, the significant benefit of this system was its bioremediation capabilities, achieving 41.7%, 31.4% and 36.2% removal of naphthalene, acenaphthene and phenanthrene, respectively, in the aerobic environment and 76.9%, 52.5% and 36.8%, respectively, in the anaerobic environment. These results demonstrated the ability of SMFCs in stimulating microorganisms for bioremediation of complex and recalcitrant PAHs.

  15. Residual indoor contamination from world trade center rubble fires as indicated by polycyclic aromatic hydrocarbon profiles.

    Science.gov (United States)

    Pleil, Joachim D; Funk, William E; Rappaport, Stephen M

    2006-02-15

    The catastrophic destruction of the World Trade Center (WTC) on Sept. 11, 2001 (9/11) created an immense dust cloud followed by fires that emitted smoke and soot into the air of New York City (NYC) well into December. Outdoor pollutant levels in lower Manhattan returned to urban background levels after about 200 days as the fires were put out and the debris cleanup was completed. However, particulate matter (PM) from the original collapse and fires also penetrated into commercial and residential buildings. This has created public concern because WTC dust is thought to cause adverse pulmonary symptoms including "WTC cough" and reduced lung capacity. Additionally, some recent studies have suggested a possible link between exposure to WTC contamination and other adverse health effects. Distinguishing between normal urban pollutant infiltration and residual WTC dust remaining in interior spaces is difficult; efforts are underway to develop such discriminator methods. Some progress has been made in identifying WTC dust by the content of fibers believed to be associated with the initial building collapse. There are also contaminants created by the fires that burned for 100 days in the debris piles of the building rubble. Using WTC ambient air samples, we have developed indicators for fire related PM based on the relative amounts of specific particle bound polycyclic aromatic hydrocarbons (PAHs) and the mass fraction of PAHs per mass of PM. These two parameters are combined, and we show a graphical method for discriminating between fire sources and urban particulate sources as applied to samples of settled dusts. We found that our PAHs based discriminator method can distinguish fire source contributions to WTC related particulate matter and dusts. Other major building fires or large open burn events could have similar PAHs characteristics. We found that random samples collected approximately 3.5 years after the WTC event from occupied indoor spaces (primarily residential

  16. Comparison of two extraction methods for the analysis of petroleum hydrocarbon residues in mallard duck eggs by GC and GC-MS

    Science.gov (United States)

    Belisle, A.A.; Gay, M.L.; Coon, N.C.

    1981-01-01

    Hydrocarbon residues in pooled eggs from a mallard duck on a diet of 25,000 ppm South Louisiana crude oil were compared after cleanup with and without saponification. The saponification procedure yielded superior reproducibility and extraction efficiency

  17. Enhancement of methane production from cassava residues by biological pretreatment using a constructed microbial consortium.

    Science.gov (United States)

    Zhang, Qinghua; He, Jiang; Tian, Min; Mao, Zhonggui; Tang, Lei; Zhang, Jianhua; Zhang, Hongjian

    2011-10-01

    In the study, a stable thermophilic microbial consortium with high cellulose-degradation ability was successfully constructed. That several species of microbes coexisted in this consortium was proved by DGGE (denaturing gradient gel electrophoresis) and sequence analysis. The cooperation and symbiosis of these microbes in this consortium enhanced their cellulose-degradation ability. The pretreatment of cassava residues mixing with distillery wastewater prior to anaerobic digestion was investigated by using this microbial consortium as inoculums in batch bioreactors at 55 °C. The experimental results showed that the maximum methane yield (259.46 mL/g-VS) of cassava residues was obtained through 12h of pretreatment by this microbial consortium, which was 96.63% higher than the control (131.95 mL/g-VS). In addition, it was also found that the maximum methane yield is obtained when the highest filter paper cellulase (FPase), carboxymethyl cellulase (CMCase) and xylanase activity and soluble COD (sCOD) are produced.

  18. [Degradation of cassava residue by the cellulose degradation composite microbial system MC1].

    Science.gov (United States)

    Guo, Peng; Wang, Xiao-Fen; Zhu, Wan-Bin; Cheng, Xu; Cui, Zong-Jun

    2008-03-01

    The lignocelluloses of cassava residue are good biomass resources. They are mainly used to produce feeds and alcohol. It is a promising approach to utilize them to produce methane. But it is difficult to use cassava residue for producing methane because of its dispersive solid matter and much water. A cellulose degradation composite microbial system MC1 was applied to degrade cassava residue discarded from cassava starch manufactory, and the composition of the lignocelluloses and the soluble ingredients of cassava residue were analyzed. After 18 days' cultivation, the total weight of the cassava residue was reduced by 47.3%, the cellulose, hemi-cellulose and lignin of the cassava residue were reduced by 22.7%, 90.4% and 11.3%, respectively, and 85% of the whole weight relief was made by MC1 within 6 days. The soluble ingredients of the cassava residue were increased from the incipient 18% to 33% in the third day which was the peak value in the process. The total amount of the volatile products, analyzed by GC-MS, came to a maximum in the sixth day. Twelve kinds of volatile products in the fermentation broth were determined, in which ethanol, acetic acid, 1, 2-ethanediol, butanoic acid and glycerine were the major compounds, and they can be utilized by methanogenic organism directly or be changed into compounds that can be utilized by methanogens organism directly. Accordingly, it is very hopeful to use MC1 to degrade cassava residue as a method of prefermentation in methane fermentation.

  19. Current state of knowledge in microbial degradation of polycyclic aromatic hydrocarbons (PAHs: a review

    Directory of Open Access Journals (Sweden)

    Debajyoti Ghosal

    2016-08-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed towards removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of

  20. Current State of Knowledge in Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs): A Review

    Science.gov (United States)

    Ghosal, Debajyoti; Ghosh, Shreya; Dutta, Tapan K.; Ahn, Youngho

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed toward removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of PAHs. The main

  1. Current State of Knowledge in Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs): A Review.

    Science.gov (United States)

    Ghosal, Debajyoti; Ghosh, Shreya; Dutta, Tapan K; Ahn, Youngho

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. The increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed toward removing PAHs from the environment. PAHs may undergo adsorption, volatilization, photolysis, and chemical oxidation, although transformation by microorganisms is the major neutralization process of PAH-contaminated sites in an ecologically accepted manner. Microbial degradation of PAHs depends on various environmental conditions, such as nutrients, number and kind of the microorganisms, nature as well as chemical property of the PAH being degraded. A wide variety of bacterial, fungal and algal species have the potential to degrade/transform PAHs, among which bacteria and fungi mediated degradation has been studied most extensively. In last few decades microbial community analysis, biochemical pathway for PAHs degradation, gene organization, enzyme system, genetic regulation for PAH degradation have been explored in great detail. Although, xenobiotic-degrading microorganisms have incredible potential to restore contaminated environments inexpensively yet effectively, but new advancements are required to make such microbes effective and more powerful in removing those compounds, which were once thought to be recalcitrant. Recent analytical chemistry and genetic engineering tools might help to improve the efficiency of degradation of PAHs by microorganisms, and minimize uncertainties of successful bioremediation. However, appropriate implementation of the potential of naturally occurring microorganisms for field bioremediation could be considerably enhanced by optimizing certain factors such as bioavailability, adsorption and mass transfer of PAHs. The main

  2. Residue pattern of polycyclic aromatic hydrocarbons during green tea manufacturing and their transfer rates during tea brewing.

    Science.gov (United States)

    Gao, Guanwei; Chen, Hongping; Liu, Pingxiang; Hao, Zhenxia; Ma, Guicen; Chai, Yunfeng; Wang, Chen; Lu, Chengyin

    2017-06-01

    Residues of polycyclic aromatic hydrocarbons (PAHs) in green tea and tea infusion were determined using gas chromatography-tandem mass spectrometry to study their dissipation pattern during green tea processing and infusion. Concentration and evaporation of PAHs during tea processing were the key factors affecting PAH residue content in product intermediates and in green tea. PAH residues in tea leaves increased by 2.4-3.1 times during the manufacture of green tea using the electric heating model. After correction to dry weight, PAH residue concentrations decreased by 33.5-48.4% during green tea processing because of PAH evaporation. Moreover, spreading and drying reduced PAH concentrations. The transfer rates of PAH residues from green tea to infusion varied from 4.6% to 7.2%, and PAH leaching was higher in the first infusion than in the second infusion. These results are useful for assessing exposure to PAHs from green tea and in formulating controls for the maximum residue level of PAHs in green tea.

  3. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Zhang, N.; Xue, M.; Lu, S.T. [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Tao, S., E-mail: taos@urban.pku.edu.c [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2011-02-15

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. - Research highlights: PAH degradation kinetics obey Logistic model. Degradation potentials depend on soil organic carbon content. Humin inhibits the development of PAH degradation activity. Nutrition support and sequestration regulate microbial degradation capacity. - Soil organic matter regulated PAH degradation potentials through nutrition support and sequestration.

  4. Study of weathering effects on the distribution of aromatic steroid hydrocarbons in crude oils and oil residues.

    Science.gov (United States)

    Wang, Chuanyuan; Chen, Bing; Zhang, Baiyu; Guo, Ping; Zhao, Mingming

    2014-01-01

    The composition and distribution of triaromatic steroid hydrocarbons in oil residues after biodegradation and photo-oxidation processes were detected, and the diagnostic ratios for oil spill identification were developed and evaluated based on the relative standard deviation (RSD) and the repeatability limit. The preferential loss of C27 methyl triaromatic steranes (MTAS) relative to C28 MTAS and C29 MTAS was shown during the photo-oxidation process. In contrast to the photochemical degradation, the MTAS with the original 20R biological configuration was preferentially degraded during the biodegradation process. The RSD of most of the diagnostic ratios of MTAS ranged from 9 to 84% during the photo-oxidation process. However, the RSDs of such ratios derived from MTAS were all hydrocarbons retained their molecular compositions after biodegradation and photo-oxidation and most of the diagnostic ratios derived from them could be efficiently used in oil spill identification.

  5. EVIDENCE FOR MICROBIAL ENHANCED ELECTRICAL CONDUCTIVITY IN HYDROCARBON-CONTAMINATED SEDIMENTS

    Science.gov (United States)

    Electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale column experiment consisting of biotic contaminated and uncontaminated columns. Microbial population numbers increased with a clear pattern of depth zonation within the ...

  6. Process of microbial degradation of petroleum hydrocarbons in the downstream of the Tamagawa river. Tamagawa karyuiki ni okeru sekiyukei tanka suiso no biseibutsu bunkai katei

    Energy Technology Data Exchange (ETDEWEB)

    Morito, M. (Sumitomo 3M Co., Kanagawa (Japan)); Okada, M.; Murakami, A. (Tokyo University of Agriculture and Technology, Tokyo (Japan). Faculty of Engineering)

    1990-12-10

    The process of biodegradation of petroleum hydrocarbons was investigated in the downstream of the Tamagawa river. Petroleum hydrocarbons, such as hexadecane, octylbenzene, and 1-methylnaphtalene were observed to be rapidly degraded by microorganisms in the water sampled from the surface of the river after a period of lag time. The longer lag time was observed in order of hexadecane hydrocarbons, but the rates was not be promoted by physical and chemical emulsification. It was suggested that petroleum hydrocarbons were degraded not in physical and chemical process in which the hydrocarbons were emulsified by microbial extracellular products, microfinded and enhanced contact area or frequency to microbes, but in biochemical process in which the microorganisms gained the ability of petroleum hydrocarbons degradation, that is, induction of production of a degrading enzyme. 12 refs., 7 figs.

  7. [Infrared Spectrum Studies of Hydrocarbon Generation and Structure Evolution of Peat Samples During Pyrolysis and Microbial Degradation].

    Science.gov (United States)

    Bao, Yuan; Ju, Yi-wen; Wei, Chong-tao; Wang, Chao-yong; Li, Xiao-shi

    2015-03-01

    Hydrocarbon generation and structural evolution would be occurred in the process of from coal-forming material (i. e. peat sample) transforming to the coal. While Fourier Transform Infrared Spectroscopy (FTIR) have a special advantages in analyzing molecular structure of samples. For understanding the characteristics of hydrocarbon generation and structural evolution of coal-forming material during the process of pyrolysis and microbial degradation, based on the physical simulation experiments of closed pyrolysis and anaerobic microbial degradation, the generation potential of thermogenic gas and biogenic gas were studied in this paper, and characteristics of molecular structure evolution and its mechanism was analyzed by FTIR technology. Results show that cumulative gas yields of hydrocarbon gases (mainly for methane) increased with experiment temperature. The gas yield of non-hydrocarbon gas (mainly for CO2) exhibited two peaks at 250 and 375 degrees C. The degradation ability of anaerobe on coal samples weakened with the maturity increasing and there was no gas generation on the pyrolysis samples with maturity from 1.6% to 1.8%. After pyrolysis, the content of hydroxyl in peat sample decreased first and then increased with the pyrolysis temperature increasing. The content of aldehyde carbonyl, methylene and phosphate reduced. The content of aromatic esters decreased with nonlinear. The bone of S-O in stretching vibration appeared after 350 degrees C and its content increased with temperature. This shows that the sulfocompound restrains the activity of methanogenic bacteria. After degradation by anaerobe, the relative content of hydroxyl, aldehyde carbonyl, aromatic esters, methylene and phosphate in peat sample dropped significantly. It is shown that the intermolecular force between these groups weakened.

  8. Stabilization of microbial residues by co-precipitation with Fe and Al oxides

    Science.gov (United States)

    Miltner, Anja; Achtenhagen, Jan; Kästner, Matthias

    2016-04-01

    Recent studies have shown that microbial residues contribute significantly to soil organic matter (SOM) formation. This material, however, is readily degradable and thus needs to be stabilized in soil. We hypothesize that the interaction with minerals, in particular co-precipitation with metal oxyhydroxides, plays an important role in stabilization of cell envelope material. We therefore analyzed the mineralization of 14C-labelled Escherichia coli cells and cell envelope fragments during incubation of the cell materials alone or after co-precipitation with either Fe or Al oxyhydroxide. We also tested the effect of environmental conditions, in particular oxygen supply and redox potential, on the stabilizing effect of the mineral phases. Co-precipitation with both Fe and Al oxyhydroxides decreased the mineralization significantly, indicating strong protection of biomass and biomass-derived fragments. Surprisingly, the mineralization of intact cells was higher than that of cell envelope fragments. This points to a higher recalcitrance of the cell envelope fragments, which therefore may be selectively enriched in SOM. Reductive conditions obtained after water-logging combined with excessive supply of an easily available carbon source resulted in increased mineralization in the treatments containing Fe oxyhydroxides, due to reductive dissolution of the Fe oxyhydroxide and thus loss of the stabilizing agent. We therefore conclude that co-precipitation with and incrustation by Fe or Al oxyhydroxides is a relevant stabilization mechanism for microbial residues. The same mechanism also may apply for SOM in general.

  9. The influence of dissolved petroleum hydrocarbon residues on natural phytoplankton biomass

    Digital Repository Service at National Institute of Oceanography (India)

    Shailaja, M.S.

    The effect of dissolved petroleum hydrocarbons in the environment on phytoplankton biomass measured as chlorophyll a was studied near the oil tanker route in the southern Bay of Bengal. In the transect from 5 degrees N, 77 degrees E to 5 degrees N...

  10. Metagenome reveals potential microbial degradation of hydrocarbon coupled with sulfate reduction in an oil-immersed chimney from Guaymas Basin

    Directory of Open Access Journals (Sweden)

    Ying eHe

    2013-06-01

    Full Text Available Deep-sea hydrothermal vent chimneys contain a high diversity of microorganisms, yet the metabolic activity and the ecological functions of the microbial communities remain largely unexplored. In this study, a metagenomic approach was applied to characterize the metabolic potential in a Guaymas hydrothermal vent chimney and to conduct comparative genomic analysis among a variety of environments with sequenced metagenomes. Complete clustering of functional gene categories with a comparative metagenomic approach showed that this Guaymas chimney metagenome was clustered most closely with a chimney metagenome from Juan de Fuca. All chimney samples were enriched with genes involved in recombination and repair, chemotaxis and flagellar assembly, highlighting their roles in coping with the fluctuating extreme deep-sea environments. A high proportion of transposases was observed in all the metagenomes from deep-sea chimneys, supporting the previous hypothesis that horizontal gene transfer may be common in the deep-sea vent chimney biosphere. In the Guaymas chimney metagenome, thermophilic sulfate reducing microorganisms including bacteria and archaea were found predominant, and genes coding for the degradation of refractory organic compounds such as cellulose, lipid, pullullan, as well as a few hydrocarbons including toluene, ethylbenzene and o-xylene were identified. Therefore, this oil-immersed chimney supported a thermophilic microbial community capable of oxidizing a range of hydrocarbons that served as electron donors for sulphate reduction under anaerobic conditions.

  11. Hydrocarbon degraders establish at the costs of microbial richness, abundance and keystone taxa after crude oil contamination in permafrost environments.

    Science.gov (United States)

    Yang, Sizhong; Wen, Xi; Shi, Yulan; Liebner, Susanne; Jin, Huijun; Perfumo, Amedea

    2016-11-25

    Oil spills from pipeline ruptures are a major source of terrestrial petroleum pollution in cold regions. However, our knowledge of the bacterial response to crude oil contamination in cold regions remains to be further expanded, especially in terms of community shifts and potential development of hydrocarbon degraders. In this study we investigated changes of microbial diversity, population size and keystone taxa in permafrost soils at four different sites along the China-Russia crude oil pipeline prior to and after perturbation with crude oil. We found that crude oil caused a decrease of cell numbers together with a reduction of the species richness and shifts in the dominant phylotypes, while bacterial community diversity was highly site-specific after exposure to crude oil, reflecting different environmental conditions. Keystone taxa that strongly co-occurred were found to form networks based on trophic interactions, that is co-metabolism regarding degradation of hydrocarbons (in contaminated samples) or syntrophic carbon cycling (in uncontaminated samples). With this study we demonstrate that after severe crude oil contamination a rapid establishment of endemic hydrocarbon degrading communities takes place under favorable temperature conditions. Therefore, both endemism and trophic correlations of bacterial degraders need to be considered in order to develop effective cleanup strategies.

  12. Hydrocarbon degraders establish at the costs of microbial richness, abundance and keystone taxa after crude oil contamination in permafrost environments

    Science.gov (United States)

    Yang, Sizhong; Wen, Xi; Shi, Yulan; Liebner, Susanne; Jin, Huijun; Perfumo, Amedea

    2016-01-01

    Oil spills from pipeline ruptures are a major source of terrestrial petroleum pollution in cold regions. However, our knowledge of the bacterial response to crude oil contamination in cold regions remains to be further expanded, especially in terms of community shifts and potential development of hydrocarbon degraders. In this study we investigated changes of microbial diversity, population size and keystone taxa in permafrost soils at four different sites along the China-Russia crude oil pipeline prior to and after perturbation with crude oil. We found that crude oil caused a decrease of cell numbers together with a reduction of the species richness and shifts in the dominant phylotypes, while bacterial community diversity was highly site-specific after exposure to crude oil, reflecting different environmental conditions. Keystone taxa that strongly co-occurred were found to form networks based on trophic interactions, that is co-metabolism regarding degradation of hydrocarbons (in contaminated samples) or syntrophic carbon cycling (in uncontaminated samples). With this study we demonstrate that after severe crude oil contamination a rapid establishment of endemic hydrocarbon degrading communities takes place under favorable temperature conditions. Therefore, both endemism and trophic correlations of bacterial degraders need to be considered in order to develop effective cleanup strategies. PMID:27886221

  13. Determination of microbial carbon sources and cycling during remediation of petroleum hydrocarbon impacted soil using natural abundance (14)C analysis of PLFA.

    Science.gov (United States)

    Cowie, Benjamin R; Greenberg, Bruce M; Slater, Gregory F

    2010-04-01

    In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study

  14. The effect of salinity, redox mediators and temperature on anaerobic biodegradation of petroleum hydrocarbons in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Adelaja, Oluwaseun, E-mail: o.adelaja@my.westminster.ac.uk; Keshavarz, Tajalli, E-mail: t.keshavarz@westminster.ac.uk; Kyazze, Godfrey, E-mail: g.kyazze@westminster.ac.uk

    2015-02-11

    Highlights: • Effective degradation of petroleum hydrocarbon mixtures was achieved using MFC. • Adapted anaerobic microbial consortium was used as inoculum. • Bio-electricity generation was enhanced by 30-fold when riboflavin, was added. • Optimum MFC performance was obtained at mesophilic and moderately saline conditions. • Stable MFC performance was obtained during prolonged fed-batch MFC operation. - Abstract: Microbial fuel cells (MFCs) need to be robust if they are to be applied in the field for bioremediation. This study investigated the effect of temperature (20–50 °C), salinity (0.5–2.5% (w/v) as sodium chloride), the use of redox mediators (riboflavin and anthraquinone-2-sulphonate, AQS) and prolonged fed-batch operation (60 days) on biodegradation of a petroleum hydrocarbon mix (i.e. phenanthrene and benzene) in MFCs. The performance criteria were degradation efficiency, % COD removal and electrochemical performance. Good electrochemical and degradation performance were maintained up to a salinity of 1.5% (w/v) but deteriorated by 35-fold and 4-fold respectively as salinity was raised to 2.5%w/v. Degradation rates and maximum power density were both improved by approximately 2-fold at 40 °C compared to MFC performance at 30 °C but decreased sharply by 4-fold when operating temperature was raised to 50 °C. The optimum reactor performance obtained at 40 °C was 1.15 mW/m{sup 2} maximum power density, 89.1% COD removal and a degradation efficiency of 97.10%; at moderately saline (1% w/v) conditions the maximum power density was 1.06 mW/m{sup 2}, 79.1% COD removal and 91.6% degradation efficiency. This work suggests the possible application of MFC technology in the effective treatment of petroleum hydrocarbons contaminated site and refinery effluents.

  15. Microbial diversity of a Mediterranean soil and its changes after biotransformed dry olive residue amendment.

    Directory of Open Access Journals (Sweden)

    José A Siles

    Full Text Available The Mediterranean basin has been identified as a biodiversity hotspot, about whose soil microbial diversity little is known. Intensive land use and aggressive management practices are degrading the soil, with a consequent loss of fertility. The use of organic amendments such as dry olive residue (DOR, a waste produced by a two-phase olive-oil extraction system, has been proposed as an effective way to improve soil properties. However, before its application to soil, DOR needs a pre-treatment, such as by a ligninolytic fungal transformation, e.g. Coriolopsis floccosa. The present study aimed to describe the bacterial and fungal diversity in a Mediterranean soil and to assess the impact of raw DOR (DOR and C. floccosa-transformed DOR (CORDOR on function and phylogeny of soil microbial communities after 0, 30 and 60 days. Pyrosequencing of the 16S rRNA gene demonstrated that bacterial diversity was dominated by the phyla Proteobacteria, Acidobacteria, and Actinobacteria, while 28S-rRNA gene data revealed that Ascomycota and Basidiomycota accounted for the majority of phyla in the fungal community. A Biolog EcoPlate experiment showed that DOR and CORDOR amendments decreased functional diversity and altered microbial functional structures. These changes in soil functionality occurred in parallel with those in phylogenetic bacterial and fungal community structures. Some bacterial and fungal groups increased while others decreased depending on the relative abundance of beneficial and toxic substances incorporated with each amendment. In general, DOR was observed to be more disruptive than CORDOR.

  16. Spatial structure and activity of sedimentary microbial communities underlying a Beggiatoa spp. mat in a Gulf of Mexico hydrocarbon seep.

    Directory of Open Access Journals (Sweden)

    Karen G Lloyd

    Full Text Available BACKGROUND: Subsurface fluids from deep-sea hydrocarbon seeps undergo methane- and sulfur-cycling microbial transformations near the sediment surface. Hydrocarbon seep habitats are naturally patchy, with a mosaic of active seep sediments and non-seep sediments. Microbial community shifts and changing activity patterns on small spatial scales from seep to non-seep sediment remain to be examined in a comprehensive habitat study. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a transect of biogeochemical measurements and gene expression related to methane- and sulfur-cycling at different sediment depths across a broad Beggiatoa spp. mat at Mississippi Canyon 118 (MC118 in the Gulf of Mexico. High process rates within the mat ( approximately 400 cm and approximately 10 cm from the mat's edge contrasted with sharply diminished activity at approximately 50 cm outside the mat, as shown by sulfate and methane concentration profiles, radiotracer rates of sulfate reduction and methane oxidation, and stable carbon isotopes. Likewise, 16S ribosomal rRNA, dsrAB (dissimilatory sulfite reductase and mcrA (methyl coenzyme M reductase mRNA transcripts of sulfate-reducing bacteria (Desulfobacteraceae and Desulfobulbaceae and methane-cycling archaea (ANME-1 and ANME-2 were prevalent at the sediment surface under the mat and at its edge. Outside the mat at the surface, 16S rRNA sequences indicated mostly aerobes commonly found in seawater. The seep-related communities persisted at 12-20 cm depth inside and outside the mat. 16S rRNA transcripts and V6-tags reveal that bacterial and archaeal diversity underneath the mat are similar to each other, in contrast to oxic or microoxic habitats that have higher bacterial diversity. CONCLUSIONS/SIGNIFICANCE: The visual patchiness of microbial mats reflects sharp discontinuities in microbial community structure and activity over sub-meter spatial scales; these discontinuities have to be taken into account in geochemical and

  17. Influence of moisture content on microbial activity and silage quality during ensilage of food processing residues.

    Science.gov (United States)

    Zheng, Yi; Yates, Matthew; Aung, Hnin; Cheng, Yu-Shen; Yu, Chaowei; Guo, Hongyun; Zhang, Ruihong; Vandergheynst, Jean; Jenkins, Bryan M

    2011-10-01

    Seasonally produced biomass such as sugar beet pulp (SBP) and tomato pomace (TP) needs to be stored properly to meet the demand of sustainable biofuel production industries. Ensilage was used to preserve the feedstock. The effect of moisture content (MC) on the performance of ensilage and the relationship between microorganism activities and MC were investigated. For SBP, MC levels investigated were 80, 55, 30, and 10% on a wet basis. For TP, MC levels investigated were 60, 45, 30, and 10%. Organic acids, ethanol, ammonia, pH and water soluble carbohydrates (WSC) were measured to evaluate the silage quality. Ensilage improved as the MC decreased from 80 to 55% for SBP and from 60 to 45% for TP. When the MC decreased to 30%, a little microbial activity was detected for both feedstocks. Storage at 10% MC prevented all the microbial activity. The naturally occurring microorganisms in TP were found to preserve TP during silage and were isolated and determined by polymerase chain reaction (PCR). The results suggest that partial drying followed by ensilage may be a good approach for stabilization of food processing residues for biofuels production.

  18. Microbial degradation of total petroleum hydrocarbons in crude oil: a field-scale study at the low-land rainforest of Ecuador.

    Science.gov (United States)

    Maddela, Naga Raju; Scalvenzi, Laura; Venkateswarlu, Kadiyala

    2016-12-26

    A field-level feasibility study was conducted to determine total petroleum hydrocarbon (TPH)-degrading potential of two bacterial strains, Bacillus thuringiensis B3 and B. cereus B6, and two fungi, Geomyces pannorum HR and Geomyces sp. strain HV, all soil isolates obtained from an oil field located in north-east region of Ecuador. Crude oil-treated soil samples contained in wooden boxes received a mixture of all the four microorganisms and were incubated for 90 days in an open low-land area of Amazon rainforest. The percent removal of TPHs in soil samples that received the mixed microbial inoculum was 87.45, indicating the great potential of the soil isolates in field-scale removal of crude oil. The TPHs-degrading efficiency was verified by determining the toxicity of residues, remained in soil after biodegradation, toward viability of Artemia salina or seed germination and plant growth of cowpea. Our results clearly suggest that the selected soil isolates of bacteria and fungi could be effectively used for large-scale bioremediation of sites contaminated with crude oil.

  19. Petroleum hydrocarbon residues in the marine environment of Bassein-Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Chouksey, M.K.; Kadam, A.N.; Zingde, M.D.

    stream_size 44891 stream_content_type text/plain stream_name Mar_Pollut_Bull_49_2004_637.pdf.txt stream_source_info Mar_Pollut_Bull_49_2004_637.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 , A... with respect to changes in the concentrations of dissolved 49 (2004) * Corresponding author. Tel.: +91-22-2636-1446x221; fax: +91-22- 2636-1573. Pollution of the sea by petroleum hydrocarbons oc- curs mainly through marine operations, land based discharges...

  20. MICROBIAL COMMUNITY STRUCTURE IN A SHALLOW HYDROCARBON-CONTAMINATED AQUIFER ASSOCIATED WITH HIGH ELECTRICAL CONDUCTIVITY

    Science.gov (United States)

    Little is known about the complex interactions between microbial communities and electrical properties in contaminated aquifers. In order to investigate possible connections between these parameters a study was undertaken to investigate the hypothesis that the degradation of hydr...

  1. Assessment of the chlorinated hydrocarbons residues contamination in edible mushrooms from the North-Eastern part of Poland.

    Science.gov (United States)

    Gałgowska, Michalina; Pietrzak-Fiećko, Renata; Felkner-Poźniakowska, Barbara

    2012-11-01

    The aim of the study was to determine the content of chlorinated hydrocarbon residues in edible mushrooms from the north-eastern part of Poland. Material consisted of two species of fungi: Xerocomus mushrooms (Xerocomus badius), Boletus mushrooms (Boletus edulis). The dried samples (cups and cut-up material) were extracted with Soxhlet method in order to obtain lipid substances. In the fat chlorinated hydrocarbons were determined by Ludwicki et al. (1996) method. The separation and quantitative determination of DDT, DDE, DDD and γ-HCH were conducted with the method of gas chromatography using an electron capture detector - ECD. In all tested samples the presence of γ-HCH, DDT and its metabolites (DDE, DDD) was detected. The higher content of γ-HCH was found in Xerocomus mushrooms (average 0.125 μg/kg of mushrooms); in the Boletus mushrooms -0.11 μg/kg of mushrooms. The content of ΣDDT in cups of Xerocomus mushrooms was more than 2-fold higher than in those of Boletus mushrooms (3.78:1.71 mg/kg of mushrooms). The opposite relationship was observed for cut-up material. The higher concentration of ΣDDT was found in Boletus mushrooms (2.26 mg/kg of mushrooms) while in Xerocomus mushrooms this content was 0.91 mg/kg of mushrooms. Despite the fact that chlorinated hydrocarbons were determined in all samples under study, their contents do not exceed acceptable levels indicating that the consumption of mushrooms does not pose a health risk to consumers from the organochlorine compounds.

  2. Effects of diurnal temperature variation on microbial community and petroleum hydrocarbon biodegradation in contaminated soils from a sub-Arctic site.

    Science.gov (United States)

    Akbari, Ali; Ghoshal, Subhasis

    2015-12-01

    Contaminated soils are subject to diurnal and seasonal temperature variations during on-site ex-situ bioremediation processes. We assessed how diurnal temperature variations similar to that in summer at the site from which petroleum hydrocarbon-contaminated soil was collected affect the soil microbial community and the extent of biodegradation of petroleum hydrocarbons compared with constant temperature regimes. Microbial community analyses for 16S rRNA and alkB genes by pyrosequencing indicated that the microbial community for soils incubated under diurnal temperature variation from 5°C to 15°C (VART5-15) evolved similarly to that for soils incubated at constant temperature of 15°C (CST15). In contrast, under a constant temperature of 5°C (CST5), the community evolved significantly different. The extent of biodegradation of C10-C16 hydrocarbons in the VART5-15 systems was 48%, comparable with the 41% biodegradation in CST15 systems, but significantly higher than CST5 systems at 11%. The enrichment of Gammaproteobacteria was observed in the alkB gene-harbouring communities in VART5-15 and CST15 but not in CST5 systems. However, the Actinobacteria was abundant at all temperature regimes. The results suggest that changes in microbial community composition as a result of diurnal temperature variations can significantly influence petroleum hydrocarbon bioremediation performance in cold regions.

  3. About the order in aerobic heterotrophic microbial communities from hydrocarbon-contaminated sites

    NARCIS (Netherlands)

    Becker, P.M.

    1999-01-01

    The organizational structure of communities of aerobic heterotrophic bacteria was studied by means of physiological and molecular typing of the members of arbitrary samples of isolates, ASsI. The isolate sample assay (ISA) was applied to three different hydrocarbon-polluted sites: a dry windrow pile

  4. About the order in aerobic heterotrophic microbial communities from hydrocarbon-contaminated sites

    NARCIS (Netherlands)

    Becker, P.M.

    1999-01-01

    The organizational structure of communities of aerobic heterotrophic bacteria was studied by means of physiological and molecular typing of the members of arbitrary samples of isolates, ASsI. The isolate sample assay (ISA) was applied to three different hydrocarbon-polluted sites: a dry windrow pile

  5. Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents.

    Science.gov (United States)

    Xi, Zemin; Chen, Baoliang

    2014-04-01

    Removal of polycyclic aromatic hydrocarbons (PAHs), e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorption kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains (i.e., exposed aromatic core). By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorption coefficients (Kd) were negatively correlated with the polarity index [(O+N)/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of

  6. The good, the bad or the ugly: Microbial biomass of biogas residues as a contributor to soil carbon cycle

    Science.gov (United States)

    Coban, H.; Miltner, A.; Kaestner, M.

    2013-12-01

    Loss of soil organic matter is a recent problem in soils all over the world. This can be related to enhanced mineralization of the soil organic matter due to land use change, which is a source of anthropogenic carbon dioxide increase. For example, the carbon input from plant residues is reduced because of the increased cultivation of bioenergy crops. In order to avoid soil degradation, application of biogas residues is a common practice in such areas. Biogas residues are side products of biogas production and contain microbial biomass. Application of these residues as soil additive influences the soil microorganisms as well as the carbon cycle. We study this effect by incubating 13C-labeled biogas residues in an arable soil from the Static Fertilization Experiment in Bad Lauchstaedt, Germany. Labeled residues were produced via labeling of active microbial biomass by addition of KH13CO3 to biogas reactors. High enrichment in the various phospholipid fatty acids proved the successful labeling of the biomass. The labeled biogas residues are being long-term incubated in the soil. During incubation, we monitor the fate of the carbon by analyzing the label in phospholipid fatty acids, amino acids as well as carbon dioxide. This allows us to trace the fate of the biogas residues-derived C in soil and to quantify the effect on the transformation of the natural soil organic matter (e.g. negative effects such as priming effects). Also, microbial community dynamics will be determined using molecular biology tools such as denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (Q-PCR). In order to prevent potentially negative effects, various additives such as charred biomaterials, clays and chopped bark will be tested to improve the carbon storage in soil. In conclusion, this study investigates the fate and impact of biogas residues used as a soil additive on the soil microbial community and amount of soil organic matter. It is aimed to understand and

  7. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Albert L., E-mail: albert.juhasz@unisa.edu.a [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Smith, Euan [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Waller, Natasha [CSIRO Land and Water, Glen Osmond, SA 5064 (Australia); Stewart, Richard [Remediate, Kent Town, SA 5067 (Australia); Weber, John [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia)

    2010-02-15

    The impact of residual PAHs (2250 +- 71 mug total PAHs g{sup -1}) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +- 1286 mug total PAHs g{sup -1}) was assessed using a variety of ecological assays. Microtox{sup TM} results for aqueous soil extracts indicated that there was no significant difference in EC{sub 50} values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  8. Deep sequencing of Myxilla (Ectyomyxilla) methanophila, an epibiotic sponge on cold-seep tubeworms, reveals methylotrophic, thiotrophic, and putative hydrocarbon-degrading microbial associations.

    Science.gov (United States)

    Arellano, Shawn M; Lee, On On; Lafi, Feras F; Yang, Jiangke; Wang, Yong; Young, Craig M; Qian, Pei-Yuan

    2013-02-01

    The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge harbors methylotrophic bacteria due to its low δ(13)C value and high methanol dehydrogenase activity, yet the full community of microbial associations in M. methanophila remained uncharacterized. In this study, we sequenced 16S rRNA genes representing the microbial community in M. methanophila collected from two hydrocarbon-seep sites (GC234 and Bush Hill) using both Sanger sequencing and next-generation 454 pyrosequencing technologies. Additionally, we compared the microbial community in M. methanophila to that of the biofilm collected from the associated tubeworm. Our results revealed that the microbial diversity in the sponges from both sites was low but the community structure was largely similar, showing a high proportion of methylotrophic bacteria of the genus Methylohalomonas and polycyclic aromatic hydrocarbon (PAH)-degrading bacteria of the genera Cycloclasticus and Neptunomonas. Furthermore, the sponge microbial clone library revealed the dominance of thioautotrophic gammaproteobacterial symbionts in M. methanophila. In contrast, the biofilm communities on the tubeworms were more diverse and dominated by the chemoorganotrophic Moritella at GC234 and methylotrophic Methylomonas and Methylohalomonas at Bush Hill. Overall, our study provides evidence to support previous suggestion that M. methanophila harbors methylotrophic symbionts and also reveals the association of PAH-degrading and thioautotrophic microbes in the sponge.

  9. Deep Sequencing of Myxilla (Ectyomyxilla) methanophila, an Epibiotic Sponge on Cold-Seep Tubeworms, Reveals Methylotrophic, Thiotrophic, and Putative Hydrocarbon-Degrading Microbial Associations

    KAUST Repository

    Arellano, Shawn M.

    2012-10-11

    The encrusting sponge Myxilla (Ectyomyxilla) methanophila (Poecilosclerida: Myxillidae) is an epibiont on vestimentiferan tubeworms at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. It has long been suggested that this sponge harbors methylotrophic bacteria due to its low δ13C value and high methanol dehydrogenase activity, yet the full community of microbial associations in M. methanophila remained uncharacterized. In this study, we sequenced 16S rRNA genes representing the microbial community in M. methanophila collected from two hydrocarbon-seep sites (GC234 and Bush Hill) using both Sanger sequencing and next-generation 454 pyrosequencing technologies. Additionally, we compared the microbial community in M. methanophila to that of the biofilm collected from the associated tubeworm. Our results revealed that the microbial diversity in the sponges from both sites was low but the community structure was largely similar, showing a high proportion of methylotrophic bacteria of the genus Methylohalomonas and polycyclic aromatic hydrocarbon (PAH)-degrading bacteria of the genera Cycloclasticus and Neptunomonas. Furthermore, the sponge microbial clone library revealed the dominance of thioautotrophic gammaproteobacterial symbionts in M. methanophila. In contrast, the biofilm communities on the tubeworms were more diverse and dominated by the chemoorganotrophic Moritella at GC234 and methylotrophic Methylomonas and Methylohalomonas at Bush Hill. Overall, our study provides evidence to support previous suggestion that M. methanophila harbors methylotrophic symbionts and also reveals the association of PAH-degrading and thioautotrophic microbes in the sponge. © 2012 Springer Science+Business Media New York.

  10. [The use of the [13C]/[12C] ratio for the assay of the microbial oxidation of hydrocarbons].

    Science.gov (United States)

    Ziakun, A M; Kosheleva, I A; Zakharchenko, V N; Kudriavtseva, A I; Peshenko, V A; Filonov, A E; Boronin, A M

    2003-01-01

    The study deals with a comparative analysis of the relative abundances of the carbon isotopes 12C and 13C in the metabolites and biomass of the Burkholderia sp. BS3702 and Pseudomonas putida BS202-p strains capable of utilizing aliphatic (n-hexadecane) and aromatic (naphthalene) hydrocarbons as sources of carbon and energy. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of Burkholderia sp. BS3702 on n-hexadecane (delta 13C = -44.6 +/- 0.2@1000) were characterized by the isotope effects delta 13CCO2 = -50.2 +/- 0.4@1000, delta 13Cbiom = -46.6 +/- 0.4@1000 and delta 13Cexo = -41.5 +/- 0.4@1000, respectively. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of the same bacterial strain on naphthalene (delta 13C = -21 +/- 0.4@1000) were characterized by the isotope effects delta 13CCO2 = -24.1 +/- 0.4@1000, delta 13Cbiom = -19.2 +/- 0.4@1000 and delta 13Cexo = -19.1 +/- 0.4@1000, respectively. The possibility of using the isotope composition of metabolic carbon dioxide for the rapid monitoring of the microbial degradation of petroleum hydrocarbons in the enviroment is discussed.

  11. Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants....mass spectrometry

    Science.gov (United States)

    A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated...

  12. Residual hydrocarbon toxicity in sediments impacted by the 1970 Arrow spill

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.; Wohlgeschaffen, G.D.; Tremblay, G.H. [Fisheries and Oceans. Inst. Maurice Lamontagne, Mont-Joli, PQ (Canada); Vandermeulen, J.H.; Mossman, D.C. [Fisheries and Oceans. Bedford Institute of Oceanography, Dartmouth, NS (Canada); Doe, K.G.; Jackman, P.M. [Environment Canada. Environmental Science Centre, Moncton, NB (Canada); Prince, R.C.; Garrett, R.M.; Haith, C.E. [Exxon Research and Engineering Co., Annandale, NJ (United States)

    1998-09-01

    An assessment of the biological effects associated with a marine oil spill that occurred more than twenty years ago was presented. In 1970, 2,045 m{sup 3} of Bunker C crude oil impacted 300 km of Nova Scotia`s coastline when the tanker Arrow ran aground. Only 10 per cent of the contaminated shoreline was subjected to cleanup. The other 90 per cent was left to degrade naturally. In 1993 and 1997, samples of sediment and interstitial water were collected in areas where residual oil from the spill was still evident. Chemical analysis has shown that the oil has undergone substantial biodegradation. As a result of natural attenuation process for more than a 20 year period, the toxicity of the residual oil has been reduced. Substantial evidence of habitat recovery was also found. 43 res., 2 tabs., 6 figs.

  13. Dynamic Autoinoculation and the Microbial Ecology of a deep Water Hydrocarbon Irruption

    Science.gov (United States)

    2012-12-11

    fundamental principles of chemistry , microbiology, and ocean physics without the need for tuning or optimization. In light of the model’s overall success...diagnostics for mixing (16) that have not been used in previous models of deep water circu- lation (17). We defined a dairy input flux of hydrocarbons dis...daily Dux estimates of oil and natural gas from the well based on rcf. 1 and subtracted the dairy recovery volumes reported from active collection

  14. Microbial degradation of petroleum hydrocarbons in estuarine sediment of Tama River in Tokyo urban area

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Akiko; Hosomi, Masaaki; Murakami, Akihiko [Tokyo Univ. of Agriculture and Technology, Chemical Engineering Dept., Tokyo (Japan); Sakakibara, Koji [Hitachi Zosen Co., Konohana, Osaka (Japan)

    1997-12-01

    Aerobic and anaerobic biodegradation rates of petroleum hydrocarbons, i.e., hexadecane (HEX), phenanthrene (PHE), and anthracene (ANT), were determined in estuarine sediment of the Tama River in urban Tokyo, followed by estimating their respective degradation potential. While in a sediment slurry, the aerobic biodegradation rates of these petroleum hydrocarbons ranged from 40 to 70 {mu}g.g{sup -1} dry sediment:day{sup -1}. The anaerobic biodegradation rate of HEX was found to be 5 -8 {mu}g.g{sup -1} dry sediment.day{sup -1}, whereas that of PHE and ANT could not be detected following a 2-month incubation. Aerobic degradation of HEX was not affected by coexistence with either PHE or ANT, nor by the salinity level. The number of HEX-, PHE-, or ANT-utilizing bacteria ranged from 5 - 10% of the total number of aerobic heterotrophic bacteria. We calculated their biodegradation potentials using the biomass of naturally existing petroleum hydrocarbon utilizing bacteria present in the sampled sediment, with results for HEX, PHE, and ANT being 1.0 -3.5, 4.2 x 10{sup -2}, and 1.2 x 10{sup -2} -9.4 x 10{sup -1} {mu}g.g{sup -1} dry sediment day{sup -1}, respectively. In the aerobic tidal sediment of the Tama River, the purification potentials of HEX, PHE, and ANT were assessed to be approximately equal to their accumulation potentials occurring at the normal water level. (Author)

  15. Evolution of Hydrocarbon-Degrading Microbial Communities in the Aftermath of the Deepwater Horizon Oil Well Blowout in the Gulf of Mexico

    Science.gov (United States)

    Andersen, G.; Dubinsky, E. A.; Chakraborty, R.; Hollibaugh, J. T.; Hazen, T. C.

    2012-12-01

    The Deepwater Horizon oil spill created large plumes of dispersed oil and gas that remained deep in the water column and stimulated growth of several deep-sea bacteria that can degrade hydrocarbons at cold temperatures. We tracked microbial community composition before, during and after the 83-day spill to determine relationships between microbial dynamics, and hydrocarbon and dissolved-oxygen concentrations. Dominant bacteria in plumes shifted drastically over time and were dependent on the concentration of hydrocarbons, and the relative quantities of insoluble and soluble oil fractions. Unmitigated flow from the wellhead early in the spill resulted in the highest concentrations of oil and relatively more n-alkanes suspended in the plume as small oil droplets. These conditions resulted in near complete dominance by alkane-degrading Oceanospirillales, Pseudomonas and Shewanella. Six-weeks into the spill overall hydrocarbon concentrations in the plume decreased and were almost entirely composed of BTEX after management actions reduced emissions into the water column. These conditions corresponded with the emergence of Colwellia, Pseudoalteromonas, Cycloclasticus and Halomonas that are capable of degrading aromatic compounds. After the well was contained dominant plume bacteria disappeared within two weeks after the spill and transitioned to an entirely different set of bacteria dominated by Flavobacteria, Methylophaga, Alteromonas and Rhodobacteraceae that were found in anomalous oxygen depressions throughout August and are prominent degraders of both high molecular weight organic matter as well as hydrocarbons. Bio-Sep beads amended with volatile hydrocarbons from MC-252 oil were used from August through September to create hydrocarbon-amended traps for attracting oil-degrading microbes in situ. Traps were placed at multiple depths on a drilling rig about 600-m from the original MC-252 oil spill site. Microbes were isolated on media using MC-252 oil as the sole

  16. Expression of the aryl hydrocarbon receptor contributes to the establishment of intestinal microbial community structure in mice

    Science.gov (United States)

    Murray, Iain A.; Nichols, Robert G.; Zhang, Limin; Patterson, Andrew D.; Perdew, Gary H.

    2016-01-01

    Environmental and genetic factors represent key components in the establishment/maintenance of the intestinal microbiota. The aryl hydrocarbon receptor (AHR) is emerging as a pleiotropic factor, modulating pathways beyond its established role as a xenobiotic sensor. The AHR is known to regulate immune surveillance within the intestine through retention of intraepithelial lymphocytes, functional redistribution of Th17/Treg balance. Consequently, environmental/genetic manipulation of AHR activity likely influences host-microbe homeostasis. Utilizing C57BL6/J Ahr−/+ and Ahr−/− co-housed littermates followed by 18 days of genotypic segregation, we examined the influence of AHR expression upon intestinal microbe composition/functionality and host physiology. 16S sequencing/quantitative PCR (qPCR) revealed significant changes in phyla abundance, particularly Verrucomicrobia together with segmented filamentous bacteria, and an increase in species diversity in Ahr−/− mice following genotypic segregation. Metagenomics/metabolomics indicate microbial composition is associated with functional shifts in bacterial metabolism. Analysis identified Ahr−/−-dependent increases in ileal gene expression, indicating increased inflammatory tone. Transfer of Ahr−/− microbiota to wild-type germ-free mice recapitulated the increase Verrucomicrobia and inflammatory tone, indicating Ahr−/−-microbial dependence. These data suggest a role for the AHR in influencing the community structure of the intestinal microbiota. PMID:27659481

  17. Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wang, Lingwen; Li, Feng; Zhan, Yu; Zhu, Lizhong

    2016-07-01

    This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p bioremediation.

  18. Polycyclic aromatic hydrocarbons (PAHs) biodegradation potential and diversity of microbial consortia enriched from tsunami sediments in Miyagi, Japan.

    Science.gov (United States)

    Bacosa, Hernando Pactao; Inoue, Chihiro

    2015-01-01

    The Great East Japan Earthquake caused tsunamis and resulted in widespread damage to human life and infrastructure. The disaster also resulted in contamination of the environment by chemicals such as polycyclic aromatic hydrocarbons (PAHs). This study was conducted to investigate the degradation potential and describe the PAH-degrading microbial communities from tsunami sediments in Miyagi, Japan. PAH-degrading bacteria were cultured by enrichment using PAH mixture or pyrene alone as carbon and energy sources. Among the ten consortia tested for PAH mixture, seven completely degraded fluorene and more than 95% of phenanthrene in 10 days, while only four consortia partially degraded pyrene. Six consortia partially degraded pyrene as a single substrate. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) revealed that each sample was dominated by unique microbial populations, regardless of sampling location. The consortia were dominated by known PAHs degraders including Sphingomonas, Pseudomonas, and Sphingobium; and previously unknown degraders such as Dokdonella and Luteimonas. A potentially novel and PAH-degrading Dokdonella was detected for the first time. PAH-ring hydroxylating dioxygenase (PAH-RHDα) gene was shown to be more effective than nidA in estimating pyrene-degrading bacteria in the enriched consortia. The consortia obtained in this study are potential candidates for remediation of PAHs contaminated soils.

  19. Polycyclic aromatic hydrocarbons degradation and microbial community shifts during co-composting of creosote-treated wood.

    Science.gov (United States)

    Covino, Stefano; Fabianová, Tereza; Křesinová, Zdena; Čvančarová, Monika; Burianová, Eva; Filipová, Alena; Vořísková, Jana; Baldrian, Petr; Cajthaml, Tomáš

    2016-01-15

    The feasibility of decontaminating creosote-treated wood (CTW) by co-composting with agricultural wastes was investigated using two bulking agents, grass cuttings (GC) and broiler litter (BL), each employed at a 1:1 ratio with the matrix. The initial concentration of total polycyclic aromatic hydrocarbons (PAHs) in CTW (26,500 mg kg(-1)) was reduced to 3 and 19% after 240 d in GC and BL compost, respectively. PAH degradation exceeded the predicted bioaccesible threshold, estimated through sequential supercritical CO2 extraction, together with significant detoxification, assessed by contact tests using Vibrio fisheri and Hordeum vulgare. GC composting was characterized by high microbial biomass growth in the early phases, as suggested by phospholipid fatty acid analyses. Based on the 454-pyrosequencing results, fungi (mostly Saccharomycetales) constituted an important portion of the microbial community, and bacteria were characterized by rapid shifts (from Firmicutes (Bacilli) and Actinobacteria to Proteobacteria). However, during BL composting, larger amounts of prokaryotic and eukaryotic PLFA markers were observed during the cooling and maturation phases, which were dominated by Proteobacteria and fungi belonging to the Ascomycota and those putatively related to the Glomeromycota. This work reports the first in-depth analysis of the chemical and microbiological processes that occur during the co-composting of a PAH-contaminated matrix.

  20. Sources and Variability of Petroleum Hydrocarbon Residues in Sediments of Chilika Lagoon, East Coast of India.

    Science.gov (United States)

    Mohanty, Bita; Muduli, Pradipta R; Cooper, Gregory; Barik, Saroja K; Mahapatro, Debasish; Behera, Alaya T; Pattnaik, Ajit K

    2017-03-14

    The spatio-temporal distribution and the controlling factors of petroleum hydrocarbons (PHCs) in sediments of Chilika lagoon was investigated. Samples were collected during three seasons and quantified using UV-fluorescence spectroscopy. Concentrations of PHCs in surface sediments varies from 0.18 to 12.13 ppm (mean 3.71 ± 3.94 ppm). Compared to the lagoon, the monitoring stations adjacent to jetties with high boating activities tend to have higher PHC concentrations, suggesting that the contribution is likely to be from fossil fuel combustion and accidental seepage. The sediment organic matter (OM) of Chilika ranges from 0.26% to 6.23%. PHC maintains a positive correlation with OM (p < 0.05; f = 0.334), indicating the long term deposition of PHC as sediment OM. However, there is no significant relation between PHC and sediment texture, indicating its negligible control over PHC. The recorded PHC concentrations are below the threshold limit (70 ppm) as classified by United States (US) National Academy of Sciences (NAS) and also lower than those reported from similar ecosystems in India and overseas. Since the long term deposition and the bioaccumulation of PHC cannot be avoided, it is essential to monitor these parameters periodically.

  1. Bidet toilet seats with warm-water tanks: residual chlorine, microbial community, and structural analyses.

    Science.gov (United States)

    Iyo, Toru; Asakura, Keiko; Nakano, Makiko; Yamada, Mutsuko; Omae, Kazuyuki

    2016-02-01

    Despite the reported health-related advantages of the use of warm water in bidets, there are health-related disadvantages associated with the use of these toilet seats, and the bacterial research is sparse. We conducted a survey on the hygienic conditions of 127 warm-water bidet toilet seats in restrooms on a university campus. The spray water from the toilet seats had less residual chlorine than their tap water sources. However, the total viable microbial count was below the water-quality standard for tap water. In addition, the heat of the toilet seats' warm-water tanks caused heterotrophic bacteria in the source tap water to proliferate inside the nozzle pipes and the warm-water tanks. Escherichia coli was detected on the spray nozzles of about 5% of the toilet seats, indicating that the self-cleaning mechanism of the spray nozzles was largely functioning properly. However, Pseudomonas aeruginosa was detected on about 2% of the toilet seats. P. aeruginosa was found to remain for long durations in biofilms that formed inside warm-water tanks. Infection-prevention measures aimed at P. aeruginosa should receive full consideration when managing warm-water bidet toilet seats in hospitals in order to prevent opportunistic infections in intensive care units, hematology wards, and other hospital locations.

  2. Weathering patterns of polycyclic aromatic hydrocarbons contained in submerged Deepwater Horizon oil spill residues when re-exposed to sunlight.

    Science.gov (United States)

    John, Gerald F; Han, Yuling; Clement, T Prabhakar

    2016-12-15

    The Deepwater Horizon (DWH) oil spill event released a large amount of sweet crude oil into the Gulf of Mexico (GOM). An unknown portion of this oil that arrived along the Alabama shoreline interacted with nearshore sediments and sank forming submerged oil mats (SOMs). A considerable amount of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), were trapped within these buried SOMs. Recent studies completed using the oil spill residues collected along the Alabama shoreline have shown that several PAHs, especially higher molecular weight PAHs (four or more aromatic rings), are slowly weathering compared to the weathering levels experienced by the oil when it was floating over the GOM. In this study we have hypothesized that the weathering rates of PAHs in SOMs have slowed down because the buried oil was isolated from direct exposure to sunlight, thus hindering the photodegradation pathway. We further hypothesized that re-exposing SOMs to sunlight can reactivate various weathering reactions. Also, SOMs contain 75-95% sand (by weight) and the entrapped sand could either block direct sunlight or form large oil agglomerates with very little exposed surface area; these processes could possibly interfere with weathering reactions. To test these hypotheses, we completed controlled experiments to study the weathering patterns of PAHs in a field recovered SOM sample after re-exposing it to sunlight. Our experimental results show that the weathering levels of several higher molecular weight PAHs have slowed down primarily due to the absence of sunlight-induced photodegradation reactions. The data also show that sand particles in SOM material could potentially interfere with photodegradation reactions.

  3. A survey of Opportunities for Microbial Conversion of Biomass to Hydrocarbon Compatible Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, Iva; Jones, Susanne B.; Santosa, Daniel M.; Dai, Ziyu; Ramasamy, Karthikeyan K.; Zhu, Yunhua

    2010-09-01

    Biomass is uniquely able to supply renewable and sustainable liquid transportation fuels. In the near term, the Biomass program has a 2012 goal of cost competitive cellulosic ethanol. However, beyond 2012, there will be an increasing need to provide liquid transportation fuels that are more compatible with the existing infrastructure and can supply fuel into all transportation sectors, including aviation and heavy road transport. Microbial organisms are capable of producing a wide variety of fuel and fuel precursors such as higher alcohols, ethers, esters, fatty acids, alkenes and alkanes. This report surveys liquid fuels and fuel precurors that can be produced from microbial processes, but are not yet ready for commercialization using cellulosic feedstocks. Organisms, current research and commercial activities, and economics are addressed. Significant improvements to yields and process intensification are needed to make these routes economic. Specifically, high productivity, titer and efficient conversion are the key factors for success.

  4. Microbial diversity and anaerobic hydrocarbon degradation potential in an oil-contaminated mangrove sediment.

    Science.gov (United States)

    Andrade, Luiza L; Leite, Deborah C A; Ferreira, Edir M; Ferreira, Lívia Q; Paula, Geraldo R; Maguire, Michael J; Hubert, Casey R J; Peixoto, Raquel S; Domingues, Regina M C P; Rosado, Alexandre S

    2012-08-30

    Mangrove forests are coastal wetlands that provide vital ecosystem services and serve as barriers against natural disasters like tsunamis, hurricanes and tropical storms. Mangroves harbour a large diversity of organisms, including microorganisms with important roles in nutrient cycling and availability. Due to tidal influence, mangroves are sites where crude oil from spills farther away can accumulate. The relationship between mangrove bacterial diversity and oil degradation in mangrove sediments remains poorly understood. Mangrove sediment was sampled from 0-5, 15-20 and 35-40 cm depth intervals from the Suruí River mangrove (Rio de Janeiro, Brazil), which has a history of oil contamination. DGGE fingerprinting for bamA, dsr and 16S rRNA encoding fragment genes, and qPCR analysis using dsr and 16S rRNA gene fragment revealed differences with sediment depth. Analysis of bacterial 16S rRNA gene diversity revealed changes with depth. DGGE for bamA and dsr genes shows that the anaerobic hydrocarbon-degrading community profile also changed between 5 and 15 cm depth, and is similar in the two deeper sediments, indicating that below 15 cm the anaerobic hydrocarbon-degrading community appears to be well established and homogeneous in this mangrove sediment. qPCR analysis revealed differences with sediment depth, with general bacterial abundance in the top layer (0-5 cm) being greater than in both deeper sediment layers (15-20 and 35-40 cm), which were similar to each other.

  5. Residual effect of storage in an elevated carbon dioxide atmosphere on the microbial flora of rock cod (Sebastes spp. )

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M.Y.; Ogrydziak, D.M.

    1986-10-01

    A residual inhibitory effect on microbial growth due to modified-atmosphere (MA) storage (MA, 80% CO/sub 2/-20% air) was demonstrated for rock cod fillets stored in MA and transferred to air at 4/sup 0/C. Results of measurements of CO/sub 2/ concentrations of the fillets suggested that the residual effect after transfer from MA to air was not due to retention of CO/sup 2/ at the surface of the fillets but was probably due to the microbial ecology of the system. Lactobacillus spp. and tan Alteromonas spp. (TAN) predominated after 7 and 14 days of storage in MA. During storage in MA, Pseudomonas spp. were inhibited or killed. Following transfer from MA to air, the percentage of the total flora represented by Lactobacillus spp. and TAN bacteria decreased, and 6 days after transfer Pseudomonas spp. were again dominant.

  6. Investigation of microbial community structure in constructed mangrove microcosms receiving wastewater-borne polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs).

    Science.gov (United States)

    Wang, Ya-fen; Wu, Yan; Pi, Na; Tam, Nora Fung-yee

    2014-04-01

    The study aims to examine relationships between microbial community structure and mixed pollutants of polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenyl ethers (PBDEs) in constructed wetland microcosms, planted with Excoecaria agallocha or Kandelia obovata, two common mangrove plant species, and under two tidal regimes, everyday tidal (Te) and no tidal flooding (Tn). Results showed both microbial community structure and the retained amounts of pollutants were significantly determined by tidal regime, while the effect of plant species was small. Higher amounts of PAHs but lower amounts of PBDEs were always retained in sediments under Te than Tn regimes. Accordingly, temporal and vertical distributions of microbial community structure differed greatly between the two tidal regimes. Redundancy analysis further revealed significant correlation between a subgroup of the mixed PAHs and PBDEs with variation in microbial community structure. The findings will help to propose specific strategies to improve the bioremediation efficiency of constructed wetland. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

    Directory of Open Access Journals (Sweden)

    Ileana Frasier

    2016-04-01

    Full Text Available The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina with rotation of sorghum (Sorghum bicolor in zero tillage alternating with rye (Secale cereale and vetch (Vicia villosa ssp. dasycarpa. Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC and community composition (DNA extraction, qPCR, and phospholipid FAME profiles were determined. Litter, aerial- and root biomass were collected and all material was analyzed for C and N. Results showed a rapid response of microbial biomass to a bacterial dominance independent of residue quality. Vetch had the highest diversity index, while the fertilized treatment had the lowest one. Vetch–sorghum rotation with high N mineralization rates and diverse microbial community sequestered more C and N in stable soil organic matter fractions than no-till sorghum alone or with rye, which had lower N turnover rates. These results reaffirm the importance of enhanced soil biodiversity for maintaining soil ecosystem functioning and services. The supply of high amounts of N-rich residues as provided by grass–legume cover crops could fulfill this objective.

  8. The effect of salinity, redox mediators and temperature on anaerobic biodegradation of petroleum hydrocarbons in microbial fuel cells.

    Science.gov (United States)

    Adelaja, Oluwaseun; Keshavarz, Tajalli; Kyazze, Godfrey

    2015-01-01

    Microbial fuel cells (MFCs) need to be robust if they are to be applied in the field for bioremediation. This study investigated the effect of temperature (20-50°C), salinity (0.5-2.5% (w/v) as sodium chloride), the use of redox mediators (riboflavin and anthraquinone-2-sulphonate, AQS) and prolonged fed-batch operation (60 days) on biodegradation of a petroleum hydrocarbon mix (i.e. phenanthrene and benzene) in MFCs. The performance criteria were degradation efficiency, % COD removal and electrochemical performance. Good electrochemical and degradation performance were maintained up to a salinity of 1.5% (w/v) but deteriorated by 35-fold and 4-fold respectively as salinity was raised to 2.5%w/v. Degradation rates and maximum power density were both improved by approximately 2-fold at 40°C compared to MFC performance at 30°C but decreased sharply by 4-fold when operating temperature was raised to 50°C. The optimum reactor performance obtained at 40°C was 1.15 mW/m(2) maximum power density, 89.1% COD removal and a degradation efficiency of 97.10%; at moderately saline (1% w/v) conditions the maximum power density was 1.06 mW/m(2), 79.1% COD removal and 91.6% degradation efficiency. This work suggests the possible application of MFC technology in the effective treatment of petroleum hydrocarbons contaminated site and refinery effluents.

  9. Microbial diversity, community composition and metabolic potential in hydrocarbon contaminated oily sludge: prospects for in situ bioremediation.

    Science.gov (United States)

    Das, Ranjit; Kazy, Sufia K

    2014-06-01

    Microbial community composition and metabolic potential have been explored in petroleum-hydrocarbon-contaminated sludge of an oil storage facility. Culture-independent clone library-based 16S rRNA gene analyses revealed that the bacterial community within the sludge was dominated by the members of β-Proteobacteria (35%), followed by Firmicutes (13%), δ-Proteobacteria (11%), Bacteroidetes (10%), Acidobacteria (6%), α-Proteobacteria (3%), Lentisphaerae (2%), Spirochaetes (2%), and unclassified bacteria (5%), whereas the archaeal community was composed of Thermoprotei (54%), Methanocellales (33%), Methanosarcinales/Methanosaeta (8%) and Methanoculleus (1%) members. Methyl coenzyme M reductase A (mcrA) gene (a functional biomarker) analyses also revealed predominance of hydrogenotrophic, methanogenic Archaea (Methanocellales, Methanobacteriales and Methanoculleus members) over acetoclastic methanogens (Methanosarcinales members). In order to explore the cultivable bacterial population, a total of 28 resident strains were identified and characterized in terms of their physiological and metabolic capabilities. Most of these could be taxonomically affiliated to the members of the genera Bacillus, Paenibacillus, Micrococcus, Brachybacterium, Aerococcus, and Zimmermannella, while two strains were identified as Pseudomonas and Pseudoxanthomonas. Metabolic profiling exhibited that majority of these isolates were capable of growing in presence of a variety of petroleum hydrocarbons as sole source of carbon, tolerating different heavy metals at higher concentrations (≥1 mM) and producing biosurfactant during growth. Many strains could grow under a wide range of pH, temperature, or salinity as well as under anaerobic conditions in the presence of different electron acceptors and donors in the growth medium. Correlation between the isolates and their metabolic properties was estimated by the unweighted pair group method with arithmetic mean (UPGMA) analysis. Overall

  10. Mathematical modeling of the biodegradation of residual hydrocarbon in a variably-saturated sand column.

    Science.gov (United States)

    Geng, Xiaolong; Boufadel, Michel C; Wrenn, Brian

    2013-04-01

    The biodegradation of heptadecane in five sand columns was modeled using a multiplicative Monod approach. Each column contained 1.0 kg of sand and 2 g of heptadecane, and was supplied with an artificial seawater solution containing nutrients at a flow rate that resulted in unsaturated flow through the column. All nutrients were provided in excess with the exception of nitrate whose influent concentration was 0.1, 0.5, 1.0, 2.5, or 5.0 mg N/L. The experiment was run around 912 h until no measurable oxygen consumption or CO2 production was observed. The residual mass of heptadecane was measured at the end of the experiments and the biodegradation was monitored based on oxygen consumption and CO2 production. Biodegradation kinetic parameters were estimated by fitting the model to experimental data of oxygen, CO2, and residual mass of heptadecane obtained from the two columns having influent nitrate-N concentration of 0.5 and 2.5 mg/L. Noting that the oxygen and CO2 measurements leveled off at around 450 h, we fitted the model to these data for that range. The estimated parameters fell in within the range reported in the literature. In particular, the half-saturation constant for nitrate utilization, [Formula: see text], was estimated to be 0.45 mg N/L, and the yield coefficient was found to be 0.15 mg biomass/mg heptadecane. Using these values, the rest of experimental data from the five columns was predicted, and the model agreed with the observations. There were some consistent discrepancies at large times between the model simulation and observed data in the cases with higher nitrate concentration. One plausible explanation for these differences could be limitation of biodegradation by reduction of the heptadecane-water interfacial area in these columns while the model uses a constant interfacial area.

  11. Bioremediation of marine sediments contaminated by hydrocarbons: experimental analysis and kinetic modeling.

    Science.gov (United States)

    Beolchini, Francesca; Rocchetti, Laura; Regoli, Francesco; Dell'Anno, Antonio

    2010-10-15

    This work deals with bioremediation experiments on harbor sediments contaminated by aliphatic and polycyclic aromatic hydrocarbons (PAHs), investigating the effects of a continuous supply of inorganic nutrients and sand amendments on the kinetics of microbial growth and hydrocarbon degradation. Inorganic nutrients stimulated microbial growth and enhanced the biodegradation of low and high molecular weight hydrocarbons, whereas sand amendment increased only the removal of high molecular weight compounds. The simultaneous addition of inorganic nutrients and sand provided the highest biodegradation (>70% for aliphatic hydrocarbons and 40% for PAHs). A semi-empirical kinetic model was successfully fitted to experimental temporal changes of hydrocarbon residual concentrations and microbial abundances. The estimated values for parameters allowed to calculate a doubling time of 2.9 d and a yield coefficient biomass/hydrocarbons 0.39 g C biomass g-1C hydrocarbons, for the treatment with the highest hydrocarbon biodegradation yield. A comparison between the organic carbon demand and temporal profiles of hydrocarbons residual concentration allowed also to calculate the relative contribution of contaminants to carbon supply, in the range 5-32%. This suggests that C availability in the sediments, influencing prokaryotic metabolism, may have cascade effects on biodegradation rates of hydrocarbons. Even if these findings do not represent a general rule and site-specific studies are needed, the approach used here can be a relevant support tool when designing bioremediation strategies on site.

  12. Degradation of polycyclic aromatic hydrocarbons in a coking wastewater treatment plant residual by an O3/ultraviolet fluidized bed reactor.

    Science.gov (United States)

    Lin, Chong; Zhang, Wanhui; Yuan, Mengyang; Feng, Chunhua; Ren, Yuan; Wei, Chaohai

    2014-09-01

    Coking wastewater treatment plant (CWWTP) represents a typical point source of polycyclic aromatic hydrocarbons (PAHs) to the water environment and threatens the safety of drinking water in downstream regions. To enhance the removal of residual PAHs from bio-treated coking wastewater, a pilot-scale O3/ultraviolet (UV) fluidized bed reactor (O3/UV FBR) was designed and different operating factors including UV irradiation intensity, pH, initial concentration, contact time, and hydraulic retention time (HRT) were investigated at an ozone level of 240 g h(-1) and 25 ± 3 °C. A health risk evaluation and cost analysis were also carried out under the continuous-flow mode. As far as we know, this is the first time an O3/UV FBR has been explored for PAHs treatment. The results indicated that between 41 and 75 % of 18 target PAHs were removed in O3/UV FBR due to synergistic effects of UV irradiation. Both increased reaction time and increased pH were beneficial for the removal of PAHs. The degradation of the target PAHs within 8 h can be well fitted by the pseudo-first-order kinetics (R (2) > 0.920). The reaction rate was also positively correlated with the initial concentrations of PAHs. The health risk assessment showed that the total amount of carcinogenic substance exposure to surface water was reduced by 0.432 g day(-1). The economic analysis showed that the O3/UV FBR was able to remove 18 target PAHs at a cost of US$0.34 m(-3). These results suggest that O3/UV FBR is efficient in removing residuals from CWWTP, thus reducing the accumulation of persistent pollutant released to surface water.

  13. Effects of aqueous media on microbial removal of sulfur from dibenzothiophene in the presence of hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Effects of the aqueous components, pH, concentration of NaCl, and volume ratios of oil-to-water on the desulfurization activity of gram-negative desulfurizing bacterium, Pseudomonas delafieldii R-8, were investigated. R-8 showed high desulfurization activity even with a concentration of NaCl up to 60 g@L-1 or high content of dodecane over 83%. The addition of NADH could increase the desulfurization activity of the whole cells. The desulfurization of DBT could be proceeded in the presence of hydrocarbons with the carbon length ranging from 6 to16. Among them, the largest specific desulfurization activity was shown in dodecane, the value of which was 1.96 mg@g-1@h-1 similar to that of R. erythropolis IGTS8.

  14. Microbial diversity and anaerobic hydrocarbon degradation potential in an oil-contaminated mangrove sediment

    Directory of Open Access Journals (Sweden)

    Andrade Luiza L

    2012-08-01

    Full Text Available Abstract Background Mangrove forests are coastal wetlands that provide vital ecosystem services and serve as barriers against natural disasters like tsunamis, hurricanes and tropical storms. Mangroves harbour a large diversity of organisms, including microorganisms with important roles in nutrient cycling and availability. Due to tidal influence, mangroves are sites where crude oil from spills farther away can accumulate. The relationship between mangrove bacterial diversity and oil degradation in mangrove sediments remains poorly understood. Results Mangrove sediment was sampled from 0–5, 15–20 and 35–40 cm depth intervals from the Suruí River mangrove (Rio de Janeiro, Brazil, which has a history of oil contamination. DGGE fingerprinting for bamA, dsr and 16S rRNA encoding fragment genes, and qPCR analysis using dsr and 16S rRNA gene fragment revealed differences with sediment depth. Conclusions Analysis of bacterial 16S rRNA gene diversity revealed changes with depth. DGGE for bamA and dsr genes shows that the anaerobic hydrocarbon-degrading community profile also changed between 5 and 15 cm depth, and is similar in the two deeper sediments, indicating that below 15 cm the anaerobic hydrocarbon-degrading community appears to be well established and homogeneous in this mangrove sediment. qPCR analysis revealed differences with sediment depth, with general bacterial abundance in the top layer (0–5 cm being greater than in both deeper sediment layers (15–20 and 35–40 cm, which were similar to each other.

  15. Enhanced reactivity of hydroxylated polycyclic aromatic hydrocarbons to birnessite in soil: reaction kinetics and nonextractable residue formation.

    Science.gov (United States)

    Jung, Jae-Woong; Lee, Seunghwan; Ryu, Hyerim; Nam, Kyoungphile; Kang, Ki-Hoon

    2008-05-01

    Phenanthrene and pyrene were not transformed by birnessite (delta-MnO2) in the presence of phenol. The phenoxy radicals generated from phenol by birnessite did not act as a mediator for polycyclic aromatic hydrocarbon radical reaction under the studied conditions. In contrast, 9-hydroxyphenanthrene and 1-hydroxypyrene were remarkably sensitive to birnessite. The disappearance patterns of the test compounds both in the aqueous phase and soil followed first-order kinetics, with a linear relationship found between the rate constants and the surface area of birnessite. Moreover, the data indicated that the reaction was faster in the presence of soil than in the aqueous phase probably because of the presence of hydroxyl groups in soil organic matter. Sequential solvent extraction was not successful in the recovery of 9-hydroxyphenanthrene from the birnessite-treated soil samples, and capillary electrophoresis data suggest the formation of nonextractable residues of the compound in soil. In addition, the acute toxicity determined by Microtox declined approximately 8.3 times in the soil samples treated with birnessite compared to untreated samples, demonstrating that the toxic compound was no longer present as its parent form.

  16. Methane-Oxidizing Bacteria Shunt Carbon to Microbial Mats at a Marine Hydrocarbon Seep

    Science.gov (United States)

    Paul, Blair G.; Ding, Haibing; Bagby, Sarah C.; Kellermann, Matthias Y.; Redmond, Molly C.; Andersen, Gary L.; Valentine, David L.

    2017-01-01

    The marine subsurface is a reservoir of the greenhouse gas methane. While microorganisms living in water column and seafloor ecosystems are known to be a major sink limiting net methane transport from the marine subsurface to the atmosphere, few studies have assessed the flow of methane-derived carbon through the benthic mat communities that line the seafloor on the continental shelf where methane is emitted. We analyzed the abundance and isotope composition of fatty acids in microbial mats grown in the shallow Coal Oil Point seep field off Santa Barbara, CA, USA, where seep gas is a mixture of methane and CO2. We further used stable isotope probing (SIP) to track methane incorporation into mat biomass. We found evidence that multiple allochthonous substrates supported the rich growth of these mats, with notable contributions from bacterial methanotrophs and sulfur-oxidizers as well as eukaryotic phototrophs. Fatty acids characteristic of methanotrophs were shown to be abundant and 13C-enriched in SIP samples, and DNA-SIP identified members of the methanotrophic family Methylococcaceae as major 13CH4 consumers. Members of Sulfuricurvaceae, Sulfurospirillaceae, and Sulfurovumaceae are implicated in fixation of seep CO2. The mats’ autotrophs support a diverse assemblage of co-occurring bacteria and protozoa, with Methylophaga as key consumers of methane-derived organic matter. This study identifies the taxa contributing to the flow of seep-derived carbon through microbial mat biomass, revealing the bacterial and eukaryotic diversity of these remarkable ecosystems.

  17. Polycyclic aromatic hydrocarbons (PAHs) biodegradation potential and diversity of microbial consortia enriched from tsunami sediments in Miyagi, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Bacosa, Hernando Pactao, E-mail: hernando.bacosa@utexas.edu [Graduate School of Environmental Studies, Tohoku University, Aoba 6-6-20, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Marine Science Institute, The University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX 78373 (United States); Inoue, Chihiro [Graduate School of Environmental Studies, Tohoku University, Aoba 6-6-20, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2015-02-11

    Highlights: • Most bacterial consortia from tsunami sediment degraded PAH mixture and pyrene. • The consortia were dominated by known and unknown PAHs-degrading bacteria. • Dokdonella clone is a potential new species and PAH degrader from tsunami sediment. • PAH-RHDα is better than nidA gene for estimating pyrene-degraders in the consortia. • First report on the PAH degradation and PAH-degrading bacteria from tsunami sediment. - Abstract: The Great East Japan Earthquake caused tsunamis and resulted in widespread damage to human life and infrastructure. The disaster also resulted in contamination of the environment by chemicals such as polycyclic aromatic hydrocarbons (PAHs). This study was conducted to investigate the degradation potential and describe the PAH-degrading microbial communities from tsunami sediments in Miyagi, Japan. PAH-degrading bacteria were cultured by enrichment using PAH mixture or pyrene alone as carbon and energy sources. Among the ten consortia tested for PAH mixture, seven completely degraded fluorene and more than 95% of phenanthrene in 10 days, while only four consortia partially degraded pyrene. Six consortia partially degraded pyrene as a single substrate. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) revealed that each sample was dominated by unique microbial populations, regardless of sampling location. The consortia were dominated by known PAHs degraders including Sphingomonas, Pseudomonas, and Sphingobium; and previously unknown degraders such as Dokdonella and Luteimonas. A potentially novel and PAH-degrading Dokdonella was detected for the first time. PAH-ring hydroxylating dioxygenase (PAH-RHDα) gene was shown to be more effective than nidA in estimating pyrene-degrading bacteria in the enriched consortia. The consortia obtained in this study are potential candidates for remediation of PAHs contaminated soils.

  18. [Bioremediation of oil-polluted soils: using the [13C]/[12C] ratio to characterize microbial products of oil hydrocarbon biodegradation].

    Science.gov (United States)

    Ziakun, A M; Brodskiĭ, E S; Baskunov, B P; Zakharchenko, V N; Peshenko, V P; Filonov, A E; Vetrova, A A; Ivanova, A A; Boronin, A M

    2014-01-01

    We compared data on the extent of bioremediation in soils polluted with oil. The data were obtained using conventional methods of hydrocarbon determination: extraction gas chromatography-mass spectrometry, extraction IR spectroscopy, and extraction gravimetry. Due to differences in the relative abundances of the stable carbon isotopes (13C/12C) in oil and in soil organic matter, these ratios could be used as natural isotopic labels of either substance. Extraction gravimetry in combination with characteristics of the carbon isotope composition of organic products in the soil before and after bioremediation was shown to be the most informative approach to an evaluation of soil bioremediation. At present, it is the only method enabling quantification of the total petroleum hydrocarbons in oil-polluted soil, as well as of the amounts of hydrocarbons remaining after bioremediation and those microbially transformed into organic products and biomass.

  19. The ecological and physiological responses of the microbial community from a semiarid soil to hydrocarbon contamination and its bioremediation using compost amendment.

    Science.gov (United States)

    Bastida, F; Jehmlich, N; Lima, K; Morris, B E L; Richnow, H H; Hernández, T; von Bergen, M; García, C

    2016-03-01

    The linkage between phylogenetic and functional processes may provide profound insights into the effects of hydrocarbon contamination and biodegradation processes in high-diversity environments. Here, the impacts of petroleum contamination and the bioremediation potential of compost amendment, as enhancer of the microbial activity in semiarid soils, were evaluated in a model experiment. The analysis of phospholipid fatty-acids (PLFAs) and metaproteomics allowed the study of biomass, phylogenetic and physiological responses of the microbial community in polluted semiarid soils. Petroleum pollution induced an increase of proteobacterial proteins during the contamination, while the relative abundance of Rhizobiales lowered in comparison to the non-contaminated soil. Despite only 0.55% of the metaproteome of the compost-treated soil was involved in biodegradation processes, the addition of compost promoted the removal of polycyclic aromatic hydrocarbons (PAHs) and alkanes up to 88% after 50 days. However, natural biodegradation of hydrocarbons was not significant in soils without compost. Compost-assisted bioremediation was mainly driven by Sphingomonadales and uncultured bacteria that showed an increased abundance of catabolic enzymes such as catechol 2,3-dioxygenases, cis-dihydrodiol dehydrogenase and 2-hydroxymuconic semialdehyde. For the first time, metaproteomics revealed the functional and phylogenetic relationships of petroleum contamination in soil and the microbial key players involved in the compost-assisted bioremediation.

  20. Bioremediation strategies of hydrocarbons and microbial diversity in the Trindade Island shoreline--Brazil.

    Science.gov (United States)

    Rodrigues, Edmo M; Kalks, Karlos H M; Fernandes, Péricles L; Tótola, Marcos R

    2015-12-30

    This study analyzed the microbial diversity colonizing the surface of an oil sample during its contact with water, off the Trindade Island coast and simulated the efficiency of eight different bioremediation strategies for this environment. The diversity analysis was performed using acrylic coupons that served as the support for an oil inclusion at sea. The coupons were sampled over 30 days, and T-RFLP multiplex was employed to access the diversity of fungi, Bacteria and Archaea present on the oil surface. The bioremediation strategies were simulated in a respirometer. The results showed that the bacterial domain was the most dominant in oil colonization and that the richness of the species attached to the oil gradually increases with the exposure time of the coupons. The combination of biostimulation and bioaugmentation with a native population was proven to be an effective strategy for the remediation of oil off the Trindade Island shoreline.

  1. Effects of polycyclic aromatic hydrocarbons on microbial community structure and PAH ring hydroxylating dioxygenase gene abundance in soil.

    Science.gov (United States)

    Sawulski, Przemyslaw; Clipson, Nicholas; Doyle, Evelyn

    2014-11-01

    Development of successful bioremediation strategies for environments contaminated with recalcitrant pollutants requires in-depth knowledge of the microorganisms and microbial processes involved in degradation. The response of soil microbial communities to three polycyclic aromatic hydrocarbons, phenanthrene (3-ring), fluoranthene (4-ring) and benzo(a)pyrene (5-ring), was examined. Profiles of bacterial, archaeal and fungal communities were generated using molecular fingerprinting techniques (TRFLP, ARISA) and multivariate statistical tools were employed to interpret the effect of PAHs on community dynamics and composition. The extent and rate of PAH removal was directly related to the chemical structure, with the 5-ring PAH benzo(a)pyrene degraded more slowly than phenathrene or fluoranthene. Bacterial, archaeal and fungal communities were all significantly affected by PAH amendment, time and their interaction. Based on analysis of clone libraries, Actinobacteria appeared to dominate in fluoranthene amended soil, although they also represented a significant portion of the diversity in phenanthrene amended and unamended soils. In addition there appeared to be more γ-Proteobacteria and less Bacteroidetes in soil amended with either PAH compared to the control. The soil bacterial community clearly possessed the potential to degrade PAHs as evidenced by the abundance of PAH ring hydroxylating (PAH-RHDα) genes from both gram negative (GN) and gram positive (GP) bacteria in PAH-amended and control soils. Although the dioxygenase gene from GP bacteria was less abundant in soil than the gene associated with GN bacteria, significant (p PAH-RHDα gene were observed during phenanthrene and fluoranthene degradation, whereas there was no significant difference in the abundance of the GN PAH-RHDα gene during the course of the experiment. Few studies to-date have examined the effect of pollutants on more than one microbial community in soil. The current study provides

  2. Spatial association analysis between hydrocarbon fields and sedimentary residual magnetic anomalies using Weights of Evidence: An example from the Triassic Province of Algeria

    Science.gov (United States)

    Allek, Karim; Boubaya, Djamel; Bouguern, Abderrahmane; Hamoudi, Mohamed

    2016-12-01

    The presence of near-surface magnetic anomalies over oil and gas accumulations and their contribution to exploration remain somewhat controversial despite encouraging results and an improved understanding of genetic links between hydrocarbon seepage-induced alterations and near-surface magnetic minerals. This controversy is likely to remain since the cause of shallow-sourced sedimentary magnetic anomalies may well be microseepage related, but could also result from other sources such as cultural features and detrital magnetite. The definite way of discriminating between them remains a challenge. In this paper we examine means to deal with this particular purpose using a Bayesian technique known as 'Weights-of-Evidence'. The technique is implemented in GIS to explore spatial associations between known hydrocarbon fields within the central Triassic province of Algeria and sedimentary residual magnetic anomalies. We use the results to show possible application of the method to the recognition of some characteristics (amplitude and width) of anomalies assumed to be induced by hydrocarbon microseepages. Our results reveal strong spatial association with certain typical class of anomalies, confirming therefore hypothesis that hydrocarbon microseepages may result in detectable magnetic anomalies. It is possible to use the anomalies occurring outside the known gas and oil fields to make informed decisions in the selection of new targets for more detailed hydrocarbon exploration.

  3. Two years after the Hebei Spirit oil spill: residual crude-derived hydrocarbons and potential AhR-mediated activities in coastal sediments.

    Science.gov (United States)

    Hong, Seongjin; Khim, Jong Seong; Ryu, Jongseong; Park, Jinsoon; Song, Sung Joon; Kwon, Bong-Oh; Choi, Kyungho; Ji, Kyunghee; Seo, Jihyun; Lee, Sangwoo; Park, Jeongim; Lee, Woojin; Choi, Yeyong; Lee, Kyu Tae; Kim, Chan-Kook; Shim, Won Joon; Naile, Jonathan E; Giesy, John P

    2012-02-07

    The Hebei Spirit oil spill occurred in December 2007 approximately 10 km off the coast of Taean, South Korea, on the Yellow Sea. However, the exposure and potential effects remain largely unknown. A total of 50 surface and subsurface sediment samples were collected from 22 sampling locations at the spill site in order to determine the concentration, distribution, composition of residual crudes, and to evaluate the potential ecological risk after two years of oil exposure. Samples were extracted and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), 20 alkyl-PAHs, 15 aliphatic hydrocarbons, and total petroleum hydrocarbons using GC-MSD. AhR-mediated activity associated with organic sediment extracts was screened using the H4IIE-luc cell bioassay. The response of the benthic invertebrate community was assessed by mapping the macrobenthic fauna. Elevated concentrations of residual crudes from the oil spill were primarily found in muddy bottoms, particularly in subsurface layers. In general, the bioassay results were consistent with the chemistry data in a dose-dependent manner, although the mass-balance was incomplete. More weathered samples containing greater fractions of alkylated PAHs exhibited greater AhR activity, due to the occurrence of recalcitrant AhR agonists present in residual oils. The macrobenthic population distribution exhibits signs of species-specific tolerances and/or recolonization of certain species such as Batillaria during weathering periods. Although the Hebei Spirit oil spill was a severe oil exposure, it appears the site is recovering two years later.

  4. Ageing processes and soil microbial community effects on the biodegradation of soil (13)C-2,4-D nonextractable residues.

    Science.gov (United States)

    Lerch, T Z; Dignac, M-F; Nunan, N; Barriuso, E; Mariotti, A

    2009-11-01

    The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of (13)C-2,4-D (NER15 and NER90, respectively) was incubated for 90 days with or without fresh soil. The addition of fresh soil had no effect on the mineralisation of NER90 or of SOM, but increased the extent and rate of NER15 mineralisation. The analyses of (13)C-enriched FAME (fatty acids methyl esters) profiles showed that the fresh soil amendment only influenced the amount and structure of microbial populations responsible for the biodegradation of NER15. By coupling biological and chemical analyses, we gained some insight into the nature and the biodegradability of pesticide NER.

  5. Microbial Biomass Changes during Decomposition of Plant Residues in a Lixisol

    Directory of Open Access Journals (Sweden)

    Kachaka, SK.

    2003-01-01

    Full Text Available A lixisol was amended with four different alley cropping species: Senna siamea, Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla. Soil samples were incubated for 140 days at 25 °C and the soil microbial biomass was determined by the ninhydrin extraction method along the incubation period. The soil microbial biomass values ranged between 80 and 600 mg.kg-1 and followed, in all cases, the decreasing order: Leucaena> Senna> Flemingia> Dactyladenia.

  6. Effect In Vitro of Antiparasitic Drugs on Microbial Inhibitor Test Responses for Screening Antibiotic Residues in Goat's Milk.

    Science.gov (United States)

    Romero, T; Beltrán, M C; Reybroeck, W; Molina, M P

    2015-09-01

    Microbial inhibitor tests are widely used to screen antibiotic residues in milk; however, these tests are nonspecific and may be affected by various substances capable of inhibiting the growth of the test microorganism. The objective of this study was to determine the effect of antiparasitic drugs in goat's milk on the microbial inhibitor test response. Raw antibiotic-free milk from Murciano-Granadina goats was supplemented with eight concentrations of seven antiparasitic substances (albendazole, 10 to 170 mg/kg; closantel, 1 to 140 mg/kg; diclazuril, 8 to 45 mg/kg; febendazole, 10 to 140 mg/kg; levamisole, 40 to 440 mg/kg; diazinon, 8 to 45 mg/kg; and ivermectin, 40 to 200 mg/kg). Twelve replicates for each concentration were analyzed with three microbial inhibitor tests: BRT MRL, Delvotest SP-NT MSC, and Eclipse 100. The results were interpreted visually (negative or positive). Using a logistic regression model, the concentrations of the antiparasitic drugs producing 5% (IC5), 10% (IC10), and 50% (IC50) positive results were determined. In general, the Eclipse 100 test was less sensitive to the effect of antiparasitic substances; the inhibitory concentrations of almost all the drugs assayed were higher than those for other tests. Conversely, the BRT MRL test was most affected, with high levels of interference at lower antiparasitic drug concentrations. Closantel and diazinon interfered with all microbial tests at lower concentrations than did other drugs (IC5 = 1 to 26 and 12 to 20 mg/kg, respectively), and higher concentrations of levamisole and diclazuril (IC5 = 30 to 240 and 50 to 117 mg/kg, respectively) were required to produce 5% positive results. These findings indicate that microbial inhibitor tests can be affected by elevated concentrations of antiparasitic drugs in goat's milk.

  7. Effect of Phenotypic Residual Feed Intake and Dietary Forage Content on the Rumen Microbial Community of Beef Cattle

    Science.gov (United States)

    Carberry, Ciara A.; Kenny, David A.; Han, Sukkyan; McCabe, Matthew S.

    2012-01-01

    Feed-efficient animals have lower production costs and reduced environmental impact. Given that rumen microbial fermentation plays a pivotal role in host nutrition, the premise that rumen microbiota may contribute to host feed efficiency is gaining momentum. Since diet is a major factor in determining rumen community structure and fermentation patterns, we investigated the effect of divergence in phenotypic residual feed intake (RFI) on ruminal community structure of beef cattle across two contrasting diets. PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) were performed to profile the rumen bacterial population and to quantify the ruminal populations of Entodinium spp., protozoa, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminococcus albus, Prevotella brevis, the genus Prevotella, and fungi in 14 low (efficient)- and 14 high (inefficient)-RFI animals offered a low-energy, high-forage diet, followed by a high-energy, low-forage diet. Canonical correspondence and Spearman correlation analyses were used to investigate associations between physiological variables and rumen microbial structure and specific microbial populations, respectively. The effect of RFI on bacterial profiles was influenced by diet, with the association between RFI group and PCR-DGGE profiles stronger for the higher forage diet. qPCR showed that Prevotella abundance was higher (P feed efficiency, although this effect may also be modulated by the diet offered. PMID:22562991

  8. Microbial life in a liquid asphalt desert.

    Science.gov (United States)

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M; Guinan, Edward; Lehto, Harry J; Hallam, Steven J

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 10(7) cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  9. Microbial Life in a Liquid Asphalt Desert

    Science.gov (United States)

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C.; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M.; Guinan, Edward; Lehto, Harry J.; Hallam, Steven J.

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 107 cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  10. Slow pyrolyzed biochars from crop residues for soil metal(loid) immobilization and microbial community abundance in contaminated agricultural soils.

    Science.gov (United States)

    Igalavithana, Avanthi Deshani; Park, Jinje; Ryu, Changkook; Lee, Young Han; Hashimoto, Yohey; Huang, Longbin; Kwon, Eilhann E; Ok, Yong Sik; Lee, Sang Soo

    2017-06-01

    This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500 °C by slow pyrolysis at a heating rate of 10 °C min(-1). Soils were incubated with 5% (w w(-1)) biochars at 25 °C and 70% water holding capacity for 45 d. The biochar effects on metal immobilization were evaluated by sequential extraction of the treated soil, and the microbial community was determined by microbial fatty acid profiles and dehydrogenase activity. The addition of WB caused the largest decrease in Pb in the exchangeable fraction (P-soil: 77.7%, U-soil: 91.5%), followed by CP (P-soil: 67.1%, U-soil: 81.1%) and PKS (P-soil: 9.1%, U-soil: 20.0%) compared to that by the control. In contrast, the additions of WB and CP increased the exchangeable As in U-soil by 84.6% and 14.8%, respectively. Alkalinity and high phosphorous content of biochars might be attributed to the Pb immobilization and As mobilization, respectively. The silicon content in biochars is also an influencing factor in increasing the As mobility. However, no considerable effects of biochars on the microbial community abundance and dehydrogenase activity were found in both soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Conversion of SPORL pretreated Douglas fir forest residues into microbial lipids with oleaginous yeasts

    Science.gov (United States)

    Douglas fir is the dominant commercial tree grown in the United States. In this study Douglas fir residue was converted to single cell oils using oleaginous yeasts. Monosaccharides were extracted from the woody biomass by pretreating with sulfite and dilute sulfuric acid (SPORL process) and hydrol...

  12. Assessment of microbial communities associated with fermentative-methanogenic biodegradation of aromatic hydrocarbons in groundwater contaminated with a biodiesel blend (B20).

    Science.gov (United States)

    Ramos, Débora Toledo; da Silva, Márcio Luís Busi; Nossa, Carlos Wolfgang; Alvarez, Pedro J J; Corseuil, Henry Xavier

    2014-09-01

    A controlled field experiment was conducted to assess the potential for fermentative-methanogenic biostimulation (by ammonium-acetate injection) to enhance biodegradation of benzene, toluene, ethylbenzene and xylenes (BTEX) as well as polycyclic aromatic hydrocarbons (PAHs) in groundwater contaminated with biodiesel B20 (20:80 v/v soybean biodiesel and diesel). Changes in microbial community structure were assessed by pyrosequencing 16S rRNA analyses. BTEX and PAH removal began 0.7 year following the release, concomitantly with the increase in the relative abundance of Desulfitobacterium and Geobacter spp. (from 5 to 52.7 % and 15.8 to 37.3 % of total Bacteria 16S rRNA, respectively), which are known to anaerobically degrade hydrocarbons. The accumulation of anaerobic metabolites acetate and hydrogen that could hinder the thermodynamic feasibility of BTEX and PAH biotransformations under fermentative/methanogenic conditions was apparently alleviated by the growing predominance of Methanosarcina. This suggests the importance of microbial population shifts that enrich microorganisms capable of interacting syntrophically to enhance the feasibility of fermentative-methanogenic bioremediation of biodiesel blend releases.

  13. [Influence of Mirabilis jalapa Linn. Growth on the Microbial Community and Petroleum Hydrocarbon Degradation in Petroleum Contaminated Saline-alkali Soil].

    Science.gov (United States)

    Jiao, Hai-hua; Cui, Bing-jian; Wu, Shang-hua; Bai, Zhi-hui; Huang, Zhan-bin

    2015-09-01

    In order to explore the effect of Mirabilis jalapa Linn. growth on the structure characteristics of the microbial community and the degradation of petroleum hydrocarbon (TPH) in the petroleum-contaminated saline-alkali soil, Microbial biomass and species in the rhizosphere soils of Mirabilis jalapa Linn. in the contaminated saline soil were studied with the technology of phospholipid fatty acids (PLFAs) analysis. The results showed that comparing to CK soils without Mirabilis jalapa Linn., the ratio of PLFAs species varied were 71. 4%, 69. 2% and 33. 3% in the spring, summer and autumn season, respectively. In addition, there was distinct difference of the biomasses of the microbial community between the CK and rhizosphere soils and among the difference seasons of growth of Mirabilis jalapa Linn.. Compare to CK soil, the degradation rates of total petroleum hydrocarbon (TPH) was increased by 47. 6%, 28. 3%, and 18. 9% in spring, summer, and autumn rhizosphere soils, respectively. Correlation analysis was used to determine the correlation between TPH degradation and the soil microbial community. 77. 8% of the total soil microbial PLFAs species showed positive correlation to the TPH degradation (the correlation coefficient r > 0), among which, 55. 6% of PLFAs species showed high positive correlation(the correlation coefficient was r≥0. 8). In addition, the relative content of SAT and MONO had high correlation with TPH degradation in the CK sample soils, the corelation coefficient were 0. 92 and 0. 60 respectively; However, the percent of positive correlation was 42. 1% in the rhizosphere soils with 21. 1% of them had high positive correlation. The relative content of TBSAT, MONO and CYCLO had moderate or low correlation in rhizosphere soils, and the correlation coefficient were 0. 56, 0. 50, and 0. 07 respectively. Our study showed that the growth of mirabilis Mirabilis jalapa Linn. had a higher influence on the species and biomass of microbial community in the

  14. Effects of bioreactor retention time on aerobic microbial decomposition of CELSS crop residues

    Science.gov (United States)

    Strayer, R. F.; Finger, B. W.; Alazraki, M. P.

    1997-01-01

    The focus of resource recovery research at the KSC-CELSS Breadboard Project has been the evaluation of microbiologically mediated biodegradation of crop residues by manipulation of bioreactor process and environmental variables. We will present results from over 3 years of studies that used laboratory- and breadboard-scale (8 and 120 L working volumes, respectively) aerobic, fed-batch, continuous stirred tank reactors (CSTR) for recovery of carbon and minerals from breadboard grown wheat and white potato residues. The paper will focus on the effects of a key process variable--bioreactor retention time--on response variables indicative of bioreactor performance. The goal is to determine the shortest retention time that is feasible for processing CELSS crop residues, thereby reducing bioreactor volume and weight requirements. Pushing the lower limits of bioreactor retention times will provide useful data for engineers who need to compare biological and physicochemical components. Bioreactor retention times were manipulated to range between 0.25 and 48 days. Results indicate that increases in retention time lead to a 4-fold increase in crop residue biodegradation, as measured by both dry weight losses and CO_2 production. A similar overall trend was also observed for crop residue fiber (cellulose and hemicellulose), with a noticeable jump in cellulose degradation between the 5.3 day and 10.7 day retention times. Water-soluble organic compounds (measured as soluble TOC) were appreciably reduced by more than 4-fold at all retention times tested. Results from a study of even shorter retention times (down to 0.25 days), in progress, will also be presented.

  15. Inhibition of residual n-hexane in anaerobic digestion of lipid-extracted microalgal wastes and microbial community shift.

    Science.gov (United States)

    Yun, Yeo-Myeong; Shin, Hang-Sik; Lee, Chang-Kyu; Oh, You-Kwan; Kim, Hyun-Woo

    2016-04-01

    Converting lipid-extracted microalgal wastes to methane (CH4) via anaerobic digestion (AD) has the potential to make microalgae-based biodiesel platform more sustainable. However, it is apparent that remaining n-hexane (C6H14) from lipid extraction could inhibit metabolic pathway of methanogens. To test an inhibitory influence of residual n-hexane, this study conducted a series of batch AD by mixing lipid-extracted Chlorella vulgaris with a wide range of n-hexane concentration (∼10 g chemical oxygen demand (COD)/L). Experimental results show that the inhibition of n-hexane on CH4 yield was negligible up to 2 g COD/L and inhibition to methanogenesis became significant when it was higher than 4 g COD/L based on quantitative mass balance. Inhibition threshold was about 4 g COD/L of n-hexane. Analytical result of microbial community profile revealed that dominance of alkane-degrading sulfate-reducing bacteria (SRB) and syntrophic bacteria increased, while that of methanogens sharply dropped as n-hexane concentration increased. These findings offer a useful guideline of threshold n-hexane concentration and microbial community shift for the AD of lipid-extracted microalgal wastes.

  16. Microbial screening for quinolones residues in cow milk by bio-optical method.

    Science.gov (United States)

    Appicciafuoco, Brunella; Dragone, Roberto; Frazzoli, Chiara; Bolzoni, Giuseppe; Mantovani, Alberto; Ferrini, Anna Maria

    2015-03-15

    The use of antibiotics on lactating cows should be monitored for the possible risk of milk contamination with residues. Accordingly, Maximum Residue Levels (MRLs) are established by the European Commission to guarantee consumers safety. As pointed out by Dec 2002/657/EC, screening is the first step in the strategy for antibiotic residue control, thus playing a key role in the whole control procedure. However, current routine screening methods applied in milk chain still fail to detect residues of quinolones at concentrations of interest. This paper reports the findings of a new bio-optical method for the screening of quinolones residues in bovine milk, based on E. coli ATCC 11303 growth inhibition. The effect of blank and spiked cow milk samples (aliquots equivalents to 0.8%, v/v) is evaluated in Mueller Hinton Broth (MHb) and MHb enriched with MgSO4 2% (MHb-Mg) inoculated with the test strain at the concentration of 10(4)CFU/mL. The presence of quinolones inhibits the cellular growth in MHb, while this effect is neutralized in MHb-Mg allowing both detection and presumptive identification of quinolones. Growth of the test strain is monitored at 37 °C in a Bioscreen C automated system, and Optical Density (OD) at 600 nm is recorded every 10 min after shaking for 10s. Growth curves (OD vs. time) of E. coli ATCC 11303 are assessed in milk samples, with and without quinolones, and their differences in terms of ΔOD (ΔOD600nm=ODMHb-Mg-ODMHb) are calculated. The presence of quinolones is detected by the cellular growth inhibition (OD vs time, none increase in the value OD) and presumptively identified through the increase of the slope of ΔOD600nm curve (ΔOD vs. time), after about 3h of incubation. The detection limit for ciprofloxacin and enrofloxacin is at the level of MRL, for marbofloxacin is at 2-fold the MRL whereas for danofloxacin is at 4-fold the MRL. Although the sensitivity of the method could be further improved and the procedure automated, it is a

  17. [Effects of Different Residue Part Inputs of Corn Straws on CO2 Efflux and Microbial Biomass in Clay Loam and Sandy Loam Black Soils].

    Science.gov (United States)

    Liu, Si-yi; Liang, Ai-zhen; Yang, Xue-ming; Zhang, Xiao-ping; Jia, Shu-xia; Chen, Xue-wen; Zhang, Shi-xiu; Sun, Bing-jie; Chen, Sheng-long

    2015-07-01

    The decomposed rate of crop residues is a major determinant for carbon balance and nutrient cycling in agroecosystem. In this study, a constant temperature incubation study was conducted to evaluate CO2 emission and microbial biomass based on four different parts of corn straw (roots, lower stem, upper stem and leaves) and two soils with different textures (sandy loam and clay loam) from the black soil region. The relationships between soil CO2 emission, microbial biomass and the ratio of carbon (C) to nitrogen (N) and lignin of corn residues were analyzed by the linear regression. Results showed that the production of CO2 was increased with the addition of different parts of corn straw to soil, with the value of priming effect (PE) ranged from 215. 53 µmol . g-1 to 335. 17 µmol . g -1. Except for corn leaves, the cumulative CO2 production and PE of clay loam soil were significantly higher than those in sandy loam soil. The correlation of PE with lignin/N was obviously more significant than that with lignin concentration, nitrogen concentration and C/N of corn residue. The addition of corn straw to soil increased the contents of MBC and MBN and decreased MBC/MBN, which suggested that more nitrogen rather than carbon was conserved in microbial community. The augmenter of microbial biomass in sandy loam soil was greater than that in clay loam soil, but the total dissolved nitrogen was lower. Our results indicated that the differences in CO2 emission with the addition of residues to soils were primarily ascribe to the different lignin/N ratio in different corn parts; and the corn residues added into the sandy loam soil could enhance carbon sequestration, microbial biomass and nitrogen holding ability relative to clay loam soil.

  18. Enhancement and inhibition of microbial activity in hydrocarbon- contaminated arctic soils: Implications for nutrient-amended bioremediation

    Science.gov (United States)

    Braddock, J.F.; Ruth, M.L.; Catterall, P.H.; Walworth, J.L.; McCarthy, K.A.

    1997-01-01

    Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.Bioremediation is being used or proposed as a treatment option at many hydrocarbon-contaminated sites. One such site is a former bulk-fuel storage facility near Barrow, AK, where contamination persists after approximately 380 m3 of JP-5 was spilled in 1970. The soil at the site is primarily coarse sand with low organic carbon (hydrocarbon concentrations declined significantly only in the soils treated at the low fertilizer level. These results indicate that an understanding of nutrient effects at a specific site is essential for successful bioremediation.

  19. Microbial Degradation of Phenols and Aromatic Hydrocarbons in Creosote-contaminated Groundwater Under Nitrate-reducing Conditions

    DEFF Research Database (Denmark)

    Flyvbjerg, John; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    Batch experiments were carried out to investigate the biodegradation of phenols and aromatic hydrocarbons under anaerobic, nitrate-reducing conditions in groundwater from a creosote-contaminated site at Fredensborg, Denmark. The bacteria in the creosote-contaminated groundwater degraded a mixture...

  20. TREATMENT OF HYDROCARBON, ORGANIC RESIDUE AND PRODUCTION CHEMICAL DAMAGE MECHANISMS THROUGH THE APPLICATION OF CARBON DIOXIDE IN NATURAL GAS STORAGE WELLS

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence J. Pekot; Ron Himes

    2004-05-31

    Core specimens and several material samples were collected from two natural gas storage reservoirs. Laboratory studies were performed to characterize the samples that were believed to be representative of a reservoir damage mechanism previously identified as arising from the presence of hydrocarbons, organic residues or production chemicals. A series of laboratory experiments were performed to identify the sample materials, use these materials to damage the flow capacity of the core specimens and then attempt to remove or reduce the induced damage using either carbon dioxide or a mixture of carbon dioxide and other chemicals. Results of the experiments showed that pure carbon dioxide was effective in restoring flow capacity to the core specimens in several different settings. However, in settings involving asphaltines as the damage mechanism, both pure carbon dioxide and mixtures of carbon dioxide and other chemicals provided little effectiveness in damage removal.

  1. Polycyclic aromatic hydrocarbons residues in Gentile di maiale, a smoked meat product typical of some mountain areas in Latina province (Central Italy

    Directory of Open Access Journals (Sweden)

    Giuseppe Carrabs

    2014-05-01

    Full Text Available Gentile di maiale is a typical meat product prepared in some traditional plants of Latina Province (Central Italy. It is obtained from dehydration, salting, smoking and ripening of swine rectum. Aim of this study was to evaluate the influence of the traditional smoking process on polycyclic aromatic hydrocarbons (PAHs content by means of high-performance liquid chromatographic/fluorescence detection. Polycyclic aromatic hydrocarbons detected in 8 samples of raw material (swine rectum and samples of smoked gentile were: benzo[a]anthracene, chrisene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a] pyrene, benzo[a,h]anthracene. Their residues were detected in all samples of finished product. European Regulation 835/2011 established two levels of PAHs content in meat products. According to first levels, in force until September 2014, only 2 out of 8 samples exceeded legal limit. According to the subsequent, more restrictive, limits all samples would be non-compliant. An improvement and a standardisation of traditional smoking procedures are recommended.

  2. TREATMENT OF HYDROCARBON, ORGANIC RESIDUE AND PRODUCTION CHEMICAL DAMAGE MECHANISMS THROUGH THE APPLICATION OF CARBON DIOXIDE IN NATURAL GAS STORAGE WELLS

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence J. Pekot

    2004-06-30

    Two gas storage fields were studied for this project. Overisel field, operated by Consumer's Energy, is located near the town of Holland, Michigan. Huntsman Storage Unit, operated by Kinder Morgan, is located in Cheyenne County, Nebraska near the town of Sidney. Wells in both fields experienced declining performance over several years of their annual injection/production cycle. In both fields, the presence of hydrocarbons, organic materials or production chemicals was suspected as the cause of progressive formation damage leading to the performance decline. Core specimens and several material samples were collected from these two natural gas storage reservoirs. Laboratory studies were performed to characterize the samples that were believed to be representative of a reservoir damage mechanism previously identified as arising from the presence of hydrocarbons, organic residues or production chemicals. A series of laboratory experiments were performed to identify the sample materials, use these materials to damage the flow capacity of the core specimens and then attempt to remove or reduce the induced damage using either carbon dioxide or a mixture of carbon dioxide and other chemicals. Results of the experiments showed that pure carbon dioxide was effective in restoring flow capacity to the core specimens in several different settings. However, in settings involving asphaltines as the damage mechanism, both pure carbon dioxide and mixtures of carbon dioxide and other chemicals provided little effectiveness in damage removal.

  3. Polycyclic Aromatic Hydrocarbons Residues in Gentile Di Maiale, a Smoked Meat Product Typical of Some Mountain Areas in Latina Province (Central Italy)

    Science.gov (United States)

    Carrabs, Giuseppe; Mercogliano, Raffaelina; Carosielli, Leonardo; Vollano, Lucia; Anastasio, Aniello

    2014-01-01

    Gentile di maiale is a typical meat product prepared in some traditional plants of Latina Province (Central Italy). It is obtained from dehydration, salting, smoking and ripening of swine rectum. Aim of this study was to evaluate the influence of the traditional smoking process on polycyclic aromatic hydrocarbons (PAHs) content by means of high-performance liquid chromatographic/fluorescence detection. Polycyclic aromatic hydrocarbons detected in 8 samples of raw material (swine rectum) and samples of smoked gentile were: benzo[a]anthracene, chrisene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a] pyrene, benzo[a,h]anthracene. Their residues were detected in all samples of finished product. European Regulation 835/2011 established two levels of PAHs content in meat products. According to first levels, in force until September 2014, only 2 out of 8 samples exceeded legal limit. According to the subsequent, more restrictive, limits all samples would be non-compliant. An improvement and a standardisation of traditional smoking procedures are recommended.

  4. Methane and other hydrocarbon gases in sediment from the southeastern North American continental margin

    Science.gov (United States)

    Kvenvolden, K.A.; Lorenson, T.D.

    2000-01-01

    Residual concentrations and distributions of hydrocarbon gases from methane to n-heptane were measured in sediments at seven sites on Ocean Drilling Program (ODP) Leg 164. Three sites were drilled at the Cape Fear Diapir of the Carolina Rise, and one site was drilled on the Blake Ridge Diapir. Methane concentrations at these sites result from microbial generation which is influenced by the amount of pore-water sulfate and possible methane oxidation. Methane hydrate was found at the Blake Ridge Diapir site. The other hydrocarbon gases at these sites are likely the produce of early microbial processes. Three sites were drilled on a transect of holes across the crest of the Blake Ridge. The base of the zone of gas-hydrate occurrence was penetrated at all three sites. Trends in hydrocarbon gas distributions suggest that methane is microbial in origin and that the hydrocarbon gas mixture is affected by diagenesis, outgassing, and, near the surface, by microbial oxidation. Methane hydrate was recovered at two of these three sites, although gas hydrate is likely present at all three sites. The method used here for determining amounts of residual hydrocarbon gases has its limitations and provides poor assessment of gas distributions, particularly in the stratigraphic interval below about ~ 100 mbsf. One advantage of the method, however, is that it yields sufficient quantities of gas for other studies such as isotopic determinations.

  5. Field trial on removal of petroleum-hydrocarbon pollutants using a microbial consortium for bioremediation and rhizoremediation.

    Science.gov (United States)

    Pizarro-Tobías, Paloma; Niqui, José L; Roca, Amalia; Solano, Jennifer; Fernández, Matilde; Bastida, Felipe; García, Carlos; Ramos, Juan L

    2015-02-01

    Petroleum waste sludges are toxic and dangerous that is why environmental protection agencies have declared their treatment top priority. Physicochemical treatments are expensive and environmentally unfriendly, while alternative biological treatments are less costly but, in general, work at a slower pace. An in situ bioremediation and rhizoremediation field scale trial was performed in an area contaminated with oil refinery sludge under semiarid climate. The bioremediation and rhizoremediation treatments included the use of an artificial consortium made up of plant growth-promoting rhizobacteria and polycyclic aromatic hydrocarbon-degrading bacteria,and the combined use of the mentioned consortium along with pasture plants respectively. Rhizoremediation revealed that the development of vegetation favoured the evolution of indigenous microbiota with potential to remove petroleum wastes. This was inferred as the decline of total petroleum hydrocarbons 7 months after the biological treatment.

  6. Screening selectively harnessed environmental microbial communities for biodegradation of polycyclic aromatic hydrocarbons in moving bed biofilm reactors.

    Science.gov (United States)

    Demeter, Marc A; Lemire, Joseph A; Mercer, Sean M; Turner, Raymond J

    2017-03-01

    Bacteria are often found tolerating polluted environments. Such bacteria may be exploited to bioremediate contaminants in controlled ex situ reactor systems. One potential strategic goal of such systems is to harness microbes directly from the environment such that they exhibit the capacity to markedly degrade organic pollutants of interest. Here, the use of biofilm cultivation techniques to inoculate and activate moving bed biofilm reactor (MBBR) systems for the degradation of polycyclic aromatic hydrocarbons (PAHs) was explored. Biofilms were cultivated from 4 different hydrocarbon contaminated sites using a minimal medium spiked with the 16 EPA identified PAHs. Overall, all 4 inoculant sources resulted in biofilm communities capable of tolerating the presence of PAHs, but only 2 of these exhibited enhanced PAH catabolic gene prevalence coupled with significant degradation of select PAH compounds. Comparisons between inoculant sources highlighted the dependence of this method on appropriate inoculant screening and biostimulation efforts.

  7. Thermophilic Dry Methane Fermentation of Distillation Residue Eluted from Ethanol Fermentation of Kitchen Waste and Dynamics of Microbial Communities.

    Science.gov (United States)

    Huang, Yu-Lian; Tan, Li; Wang, Ting-Ting; Sun, Zhao-Yong; Tang, Yue-Qin; Kida, Kenji

    2017-01-01

    Thermophilic dry methane fermentation is advantageous for feedstock with high solid content. Distillation residue with 65.1 % moisture content was eluted from ethanol fermentation of kitchen waste and subjected to thermophilic dry methane fermentation, after adjusting the moisture content to 75 %. The effect of carbon to nitrogen (C/N) ratio on thermophilic dry methane fermentation was investigated. Results showed that thermophilic dry methane fermentation could not be stably performed for >10 weeks at a C/N ratio of 12.6 and a volatile total solid (VTS) loading rate of 1 g/kg sludge/d; however, it was stably performed at a C/N ratio of 19.8 and a VTS loading rate of 3 g/kg sludge/d with 83.4 % energy recovery efficiency. Quantitative PCR analysis revealed that the number of bacteria and archaea decreased by two orders of magnitude at a C/N ratio of 12.6, whereas they were not influenced at a C/N ratio of 19.8. Microbial community analysis revealed that the relative abundance of protein-degrading bacteria increased and that of organic acid-oxidizing bacteria and acetic acid-oxidizing bacteria decreased at a C/N ratio of 12.6. Therefore, there was accumulation of NH4(+) and acetic acid, which inhibited thermophilic dry methane fermentation.

  8. Conversion of residual organics in corn stover-derived biorefinery stream to bioenergy via a microbial fuel cell.

    Science.gov (United States)

    Borole, Abhijeet P; Hamilton, Choo Y; Schell, Daniel J

    2013-01-02

    A biorefinery process typically uses about 4-10 times more water than the amount of biofuel generated. The wastewater produced in a biorefinery process contains residual sugars, 5-furfural, phenolics, and other pretreatment and fermentation byproducts. Treatment of the wastewater can reduce the need for fresh water and potentially add to the environmental benefits of the process. Use of microbial fuel cells (MFCs) for conversion of the complete range of phenolic compounds and furan aldehyde derivatives present in a postfermentation biorefinery stream is reported here. The consortium was capable of removing the molecules simultaneously with sugars, which were present at 2 orders of magnitude higher concentrations. Organic loading in a fed-batch MFC affected Coulombic efficiency, which decreased from 40% at 0.66 g/L loading to 1.8% at 66.4 g/L loading. Power density increased with loading reaching 1180 mW/m(2) at 5.3 g/L (8% dilution), but decreased thereafter. Excessive loading leads to poor electrogenic performance; therefore, operation of an MFC at an intermediate loading using dilution and recirculation of the process stream can enable effective treatment with bioenergy recovery.

  9. Quantitative analysis of ruminal methanogenic microbial populations in beef cattle divergent in phenotypic residual feed intake (RFI) offered contrasting diets.

    Science.gov (United States)

    Carberry, Ciara A; Kenny, David A; Kelly, Alan K; Waters, Sinéad M

    2014-01-01

    Methane (CH4) emissions in cattle are an undesirable end product of rumen methanogenic fermentative activity as they are associated not only with negative environmental impacts but also with reduced host feed efficiency. The aim of this study was to quantify total and specific rumen microbial methanogenic populations in beef cattle divergently selected for residual feed intake (RFI) while offered (i) a low energy high forage (HF) diet followed by (ii) a high energy low forage (LF) diet. Ruminal fluid was collected from 14 high (H) and 14 low (L) RFI animals across both dietary periods. Quantitative real time PCR (qRT-PCR) analysis was conducted to quantify the abundance of total and specific rumen methanogenic microbes. Spearman correlation analysis was used to investigate the association between the relative abundance of methanogens and animal performance, rumen fermentation variables and diet digestibility. Abundance of methanogens, did not differ between RFI phenotypes. However, relative abundance of total and specific methanogen species was affected (P < 0.05) by diet type, with greater abundance observed while animals were offered the LF compared to the HF diet. These findings suggest that differences in abundance of specific rumen methanogen species may not contribute to variation in CH4 emissions between efficient and inefficient animals, however dietary manipulation can influence the abundance of total and specific methanogen species.

  10. Impact of Irradiation and Polycyclic Aromatic Hydrocarbon Spiking on Microbial Populations in Marine Sediment for Future Aging and Biodegradability Studies

    OpenAIRE

    Melcher, Rebecca J.; Apitz, Sabine E; Hemmingsen, Barbara B.

    2002-01-01

    Experiments were carried out to develop methods to generate well-characterized, polycyclic aromatic hydrocarbon (PAH)-spiked, aged but minimally altered sediments for fate, biodegradation, and bioavailability experiments. Changes in indigenous bacterial populations were monitored in mesocosms constructed of relatively clean San Diego Bay sediments, with and without exposure to gamma radiation, and then spiked with five different PAHs and hexadecane. While phenanthrene and chrysene degraders w...

  11. Microbial diversity and hydrocarbon degrading gene capacity of a crude oil field soil as determined by metagenomics analysis.

    Science.gov (United States)

    Abbasian, Firouz; Palanisami, Thavamani; Megharaj, Mallavarapu; Naidu, Ravi; Lockington, Robin; Ramadass, Kavitha

    2016-05-01

    Soils contaminated with crude oil are rich sources of enzymes suitable for both degradation of hydrocarbons through bioremediation processes and improvement of crude oil during its refining steps. Due to the long term selection, crude oil fields are unique environments for the identification of microorganisms with the ability to produce these enzymes. In this metagenomic study, based on Hiseq Illumina sequencing of samples obtained from a crude oil field and analysis of data on MG-RAST, Actinomycetales (9.8%) were found to be the dominant microorganisms, followed by Rhizobiales (3.3%). Furthermore, several functional genes were found in this study, mostly belong to Actinobacteria (12.35%), which have a role in the metabolism of aliphatic and aromatic hydrocarbons (2.51%), desulfurization (0.03%), element shortage (5.6%), and resistance to heavy metals (1.1%). This information will be useful for assisting in the application of microorganisms in the removal of hydrocarbon contamination and/or for improving the quality of crude oil. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:638-648, 2016.

  12. Total Phosphate Influences the Rate of Hydrocarbon Degradation but Phosphate Mineralogy Shapes Microbial Community Composition in Cold-Region Calcareous Soils.

    Science.gov (United States)

    Siciliano, Steven D; Chen, Tingting; Phillips, Courtney; Hamilton, Jordan; Hilger, David; Chartrand, Blaine; Grosskleg, Jay; Bradshaw, Kris; Carlson, Trevor; Peak, Derek

    2016-05-17

    Managing phosphorus bioaccessibility is critical for the bioremediation of hydrocarbons in calcareous soils. This paper explores how soil mineralogy interacts with a novel biostimulatory solution to both control phosphorus bioavailability and influence bioremediation. Two large bore infiltrators (1 m diameter) were installed at a PHC contaminated site and continuously supplied with a solution containing nutrients and an electron acceptor. Soils from eight contaminated sites were prepared and pretreated, analyzed pretrial, spiked with diesel, placed into nylon bags into the infiltrators, and removed after 3 months. From XAS, we learned that three principal phosphate phases had formed: adsorbed phosphate, brushite, and newberyite. All measures of biodegradation in the samples (in situ degradation estimates, mineralization assays, culturable bacteria, catabolic genes) varied depending upon the soil's phosphate speciation. Notably, adsorbed phosphate increased anaerobic phenanthrene degradation and bzdN catabolic gene prevalence. The dominant mineralogical constraints on community composition were the relative amounts of adsorbed phosphate, brushite, and newberyite. Overall, this study finds that total phosphate influences microbial community phenotypes whereas relative percentages of phosphate minerals influences microbial community genotype composition.

  13. Production of novel microbial flocculants by Klebsiella sp. TG-1 using waste residue from the food industry and its use in defecating the trona suspension.

    Science.gov (United States)

    Liu, Zhan-Ying; Hu, Zhi-Quan; Wang, Tao; Chen, Yan-Ying; Zhang, Jianbin; Yu, Jing-Ran; Zhang, Tong; Zhang, Yong-Feng; Li, Yong-Li

    2013-07-01

    A microbial-flocculants-producing (MBF-producing) bacterium, named TG-1, was isolated from waste water of a starch factory, and identified as Klebsiella sp. TG-1. The microbial flocculants (MBF) produced by TG-1, named as MBF-TG-1, was applied to defecating the strong basic trona suspension in the trona industry. After optimizing medium and culturing conditions with single-factor and orthogonal designs, the highest flocculation rate of 86.9% was achieved. Chemical analysis showed that the purified microbial flocculants (MBF-TG-1) was mainly composed of polysaccharides (84.6%), with a small amount of protein or amino acid (11.1%). Bridging mechanism was supposed as the main flocculation mechanism by analyzing the flocculation process and the biochemistry properties of MBF-TG-1. The high flocculation rate (84%) was also achieved with a low-cost medium (the solid residue of tofu production from food industry).

  14. Microbial Degradation of Phenols and Aromatic Hydrocarbons in Creosote-contaminated Groundwater Under Nitrate-reducing Conditions

    DEFF Research Database (Denmark)

    Flyvbjerg, John; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    Batch experiments were carried out to investigate the biodegradation of phenols and aromatic hydrocarbons under anaerobic, nitrate-reducing conditions in groundwater from a creosote-contaminated site at Fredensborg, Denmark. The bacteria in the creosote-contaminated groundwater degraded a mixture......-reducing batches disappearance of toluene, phenol, o-cresol and o-cresol was observed, whereas no removal of benzene, the xylenes, naphthalane, 2,3-DMP, 2,4-DMP, 2,5-DMP and 3,5-DMP was detected during 7 months of incubation....

  15. Impact of microbial/plant interactions on the transformation of polycyclic aromatic hydrocarbons in rhizosphere of Festuca arundinacea.

    Science.gov (United States)

    Ho, C H; Applegate, B; Banks, M K

    2007-01-01

    The promotion of polycyclic aromatic hydrocarbon (PAH) degradation was demonstrated in the rhizosphere of Festuca arundinacea with Pseudomonas fluorescens. P. fluorescens 5RL more significantly interacted with salicylate and dextrose in the agar containing tall fescue than agar without plant roots. Although the presence of tall fescue did not promote catabolic enzyme induction in the absence of salicylate, an increase in dioxygenase activity relative to no plant controls implies that this plant may enhance the degradation of PAHs or facilitate the genotypes that are capable of transforming PAH in the rhizosphere.

  16. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Science.gov (United States)

    Hai-Ming, Tang; Xiao-Ping, Xiao; Wen-Guang, Tang; Ye-Chun, Lin; Ke, Wang; Guang-Li, Yang

    2014-01-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L.) (R-R-Ry), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice-rice-rape (Brassica napus L.) (R-R-Ra) and rice-rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (Pwinter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  17. Assessment of microbial community changes and limiting factors during bioremediation of hydrocarbon-polluted soil with new miniaturized physiological methods

    OpenAIRE

    Kaufmann, Karin; Holliger, Hans Christof

    2005-01-01

    Due to human activities, organic pollutants are spilled to the environment where they threaten public health, often as contaminants of soil or groundwater. Living organisms are able to transform or mineralize many organic pollutants, and bioremediation techniques have been developed to remove pollutants from a contaminated site. However, fast and easy methods to document both the efficacy of bioremediation and the changes in soil microbial communities during bioremediation are not well develo...

  18. Methanogenic degradation of petroleum hydrocarbons in subsurface environments remediation, heavy oil formation, and energy recovery.

    Science.gov (United States)

    Gray, N D; Sherry, A; Hubert, C; Dolfing, J; Head, I M

    2010-01-01

    Hydrocarbons are common constituents of surface, shallow, and deep-subsurface environments. Under anaerobic conditions, hydrocarbons can be degraded to methane by methanogenic microbial consortia. This degradation process is widespread in the geosphere. In comparison with other anaerobic processes, methanogenic hydrocarbon degradation is more sustainable over geological time scales because replenishment of an exogenous electron acceptor is not required. As a consequence, this process has been responsible for the formation of the world's vast deposits of heavy oil, which far exceed conventional oil assets such as those found in the Middle East. Methanogenic degradation is also a potentially important component of attenuation in hydrocarbon contamination plumes. Studies of the organisms, syntrophic partnerships, mechanisms, and geochemical signatures associated with methanogenic hydrocarbon degradation have identified common themes and diagnostic markers for this process in the subsurface. These studies have also identified the potential to engineer methanogenic processes to enhance the recovery of energy assets as biogenic methane from residual oils stranded in petroleum systems.

  19. Spatial distribution of polycyclic aromatic hydrocarbons in soil, sediment, and combusted residue at an e-waste processing site in southeast China.

    Science.gov (United States)

    Leung, Anna O W; Cheung, Kwai Chung; Wong, Ming Hung

    2015-06-01

    The environmental pollution and health impacts caused by the primitive and crude recycling of e-waste have become urgent global issues. Guiyu, China is a major hotspot of e-waste recycling. In this study, the levels and distribution of polycyclic aromatic hydrocarbons in soil in Guiyu were determined to investigate the effect of e-waste activities on the environment and to identify possible sources of these pollutants. Sediment samples from a local duck pond, water gullies, a river tributary, and combusted residue from e-waste burning sites were also investigated. The general trend found in soil (Σ16 PAHs) was acid leaching site > duck pond > rice field > printer roller dump site > reservoir (control site) and ranged from 95.2 ± 54.2 to 5,210 ± 89.6 ng/g (dry wt). The highest average total PAH concentrations were found in combusted residues of wires, cables, and other computer electrical components located at two e-waste open burning sites (18,600 and 10,800 ± 3,940 ng/g). These were 195- and 113-fold higher than the PAH concentrations of soil at the control site. Sediment PAH concentrations ranged from 37.2 ± 6 to 534 ± 271 ng/g. Results of this study provide further evidence of significant input of PAHs to the environment attributed to crude e-waste recycling.

  20. Methyl-beta-cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and associated microbial activity in contaminated soil.

    Science.gov (United States)

    Sun, Mingming; Luo, Yongming; Christie, Peter; Jia, Zhongjun; Li, Zhengao; Teng, Ying

    2012-01-01

    The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-beta-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH-degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases (p PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.

  1. Methyl-β-cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and associated microbial activity in contaminated soil

    Institute of Scientific and Technical Information of China (English)

    Mingming Sun; Yongming Luo; Peter Christie; Zhongjun Jia; Zhengao Li; Ying Teng

    2012-01-01

    The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern.The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bipavailability due to limited aqueous solubility or a large magnitude of sorption.The objective of this research was to evaluate the effect of methyl-β-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp.strain HPD-2 of an aged PAH-contaminated soil.When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp.strain HPD-2,the percentage degradation of total PAHs was significantly enhanced up to 34.8%.Higher counts of culturable PAH-degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil.This MCD-assisted bioaugmentation strategy showed significant increases (p < 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay,Shannon-Weaver index (H) and Simpson index (λ) compared with the controls,implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil.The results suggest that MCD-aided bioaugmentation by Paracoccus sp.strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils.

  2. Hydrocarbon pneumonia

    Science.gov (United States)

    Pneumonia - hydrocarbon ... Coughing Fever Shortness of breath Smell of a hydrocarbon product on the breath Stupor (decreased level of ... Most children who drink or inhale hydrocarbon products and develop ... hydrocarbons may lead to rapid respiratory failure and death.

  3. In-situ sanitation of hydrocarbon polluted soils. Vol. 2. Subordinate project: Microbial studies on hydrocarbon degradation. Final report; In-Situ-Sanierung kohlenwasserstoffbelasteter Boeden. Bd. 2. Teilprojekt: Mikrobiologische Untersuchungen zum Kohlenwasserstoffabbau. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pommeranz, S.; Boldrin, B.; Tiehm, A.; Zipperle, J.; Fritzsche, C.; Zumft, W.

    1993-09-01

    One aim of the subproject at the department of microbiology was to identify microorganisms capable of degrading components of soil pollutants typically emitted by gas works. Binuclear, trinuclear, and tetranuclear polycyclic aromatic hydrocarbons (PAH) were used as test substances, namely naphthaliene, phenanthrene, fluorene, anthracene, fluoranthene, and pyrene. The results show that there are numerous and diverse competent microbial species in the soil of the gas works premises in the east of Karlsruhe. Of the 23 soil samples examined 20 contained PAH degrading microorganisms. Of the 355 isolates tested individually 168 degraded naphthalene, 34 enthracene, 37 fluorene, 25 fluoranthene, and 5 pyrene. Competent pure and mixed cultures were isolated for each of the model substances used. This shows that the antochtonous populations have adapted to the conditions after the accident and that the soil contains PAH degrading microorganisms (70% of isolates in a sample). The PAH degrading bacteria belong to different species: many were identified as pseudomonas sp., but alcaligues sp., acinetobacter sp. and myobacterium sp. were also found. (orig./EF) [Deutsch] Ein Schwerpunkt des Teilprojektes am Lehrstuhl fuer Mikrobiologie war die Erfassung der Mikroorganismen, die Komponenten von gaswerksspezifischen Bodenkontaminationen abbauen koennen. Als Leitsubstanzen wurden die 2-, 3-, und 4-kernigen polyzyklischen aromatischen Kohlenwasserstoffe (PAK) Naphthalin, Phenanthren, Fluoren, Anthracen, Fluoranthen und Pyren ausgewaehlt. Die Ergebnisse zeigen deutlich die hohe Anzahl und Diversitaet kompetenter Mikroorganismen im Boden des ehemaligen Gaswerksgelaendes Karlsruhe-Ost. Insgesamt wurden in 20 von 23 untersuchten Bodenproben PAK-verwertende Mikroorganismen nachgewiesen. Von 355 einzeln getesteten Isolaten verwerteten 168 Naphthalin, 163 Phenanthren, 34 Anthracen, 37 Fluoren, 25 Fluoranthen und 5 Pyren. Fuer jede verwendete Modellsubstanz wurden kompetente Misch- und

  4. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Directory of Open Access Journals (Sweden)

    Tang Hai-Ming

    Full Text Available Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L. system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L. (R-R-Ry, rice-rice-Chinese milk vetch (Astragalus sinicus L. (R-R-Mv, rice-rice-rape (Brassica napus L. (R-R-Ra and rice-rice with winter fallow (R-R-Fa. The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (P<0.05 than in the R-R-Fa system during the early and late rice season. The β-glucosidase activities reached peak values at the tillering stage after residue application, and alkaline phosphatase activities reached peak values at the booting stage after residue application, respectively, the activities of β-glucosidase and alkaline phosphatase gradually decreased after this. Arylsulfatase activities reached peak values at the maturity stage. Arylamidase activities reached peak values at the maturity stage. The numbers of aerobic bacteria, actinomycete and fungus of residue treatments were significantly higher (P<0.05 than that the R-R-Ra system. However, the number of anaerobic bacteria under the R-R-Ry and R-R-Mv systems was significantly lower (P<0.05 than that under the R-R-Fa system during early rice and late rice growth stage. Thus, incorporation of winter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  5. Determining the group hydrocarbon composition of oil distillates and residues using highly effective liquid chromatography. 2. A method for determining the calibrating coefficients based on the specific weight of a petroleum product

    Energy Technology Data Exchange (ETDEWEB)

    Sadas, M.; Yetsuro, N.

    1984-01-01

    The calibrating coefficients (F) for saturated hydrocarbons (Uv) and aromatic hydrocarbons (ArU) proceeding from data based on d 15/4 for the studied petroleum products were identified in order to evaluate the group hydrocarbon composition of petroleum distillates and residues using high resolution liquid chromatography (VEZhKh). The relationship between d 15/4 and deltan (the difference in the refraction index between d 15/4 and n-C6H14) for each type of hydrocarbon was used for this purpose. The relationships between the calibrating coefficients and deltan are studied for solutions of pure hydrocarbons in n-C6H14. (The calibrating coefficients are not proportional to delatn). The effect of the length of the tower and the packing on the relationship between the calibrating coefficients and deltan is also studied. Standard compounds are selected to determine the relationship between the calibrating coefficients and deltan. The relationship is expressed by the formula F = A(1 - Bexp(-Cdeltan)), where A, B and C are constants. Good agreement is observed for the values of the calibrating coefficients calculated by this method and measured by a known method.

  6. Microbial methane oxidation as a means of treating residual emissions during passive landfill venting; Mikrobielle Methanoxidation zur Behandlung von Rest-Emissionen bei der passiven Deponieentgasung

    Energy Technology Data Exchange (ETDEWEB)

    Gebert, J.; Groengroeft, A. [Hamburg Univ. (Germany). Inst. fuer Bodenkunde

    2005-07-01

    Microbial oxidation of methane in biofilters provides a way of treating residual or lean gas emissions from landfills whose methane content and quantities no longer meet the minimum requirements for gas utilisation or flaring. In this process methane is oxidised by methanotropic bacteria in the presence of atmospheric oxygen. This yields carbon dioxide, which is less hazardous on account of its nonflammability and lower global warming potential. This contribution describes the methane degradation performance and performance governing factors of a biofilter which was exposed to a passive gas flow and observed over a period of two years.

  7. Ageing processes and soil microbial community effects on the biodegradation of soil {sup 13}C-2,4-D nonextractable residues

    Energy Technology Data Exchange (ETDEWEB)

    Lerch, T.Z., E-mail: thomas.lerch@grignon.inra.f [BIOEMCO (CNRS-UMPC-AgroParisTech-ENS-INRA), Campus INRA, 78850 Thiverval-Grignon (France); EGC - INRA-AgroParisTech, Campus INRA, 78850 Thiverval-Grignon (France); Dignac, M.-F.; Nunan, N. [BIOEMCO (CNRS-UMPC-AgroParisTech-ENS-INRA), Campus INRA, 78850 Thiverval-Grignon (France); Barriuso, E. [EGC - INRA-AgroParisTech, Campus INRA, 78850 Thiverval-Grignon (France); Mariotti, A. [BIOEMCO (CNRS-UMPC-AgroParisTech-ENS-INRA), Campus INRA, 78850 Thiverval-Grignon (France)

    2009-11-15

    The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of {sup 13}C-2,4-D (NER15 and NER90, respectively) was incubated for 90 days with or without fresh soil. The addition of fresh soil had no effect on the mineralisation of NER90 or of SOM, but increased the extent and rate of NER15 mineralisation. The analyses of {sup 13}C-enriched FAME (fatty acids methyl esters) profiles showed that the fresh soil amendment only influenced the amount and structure of microbial populations responsible for the biodegradation of NER15. By coupling biological and chemical analyses, we gained some insight into the nature and the biodegradability of pesticide NER. - Ageing processes influence the NER mineralisation rate and the microbial population involved.

  8. Biological effects of native and exotic plant residues on plant growth, microbial biomass and N availability under controlled conditions

    OpenAIRE

    Diallo, Mariama-Dalanda; Duponnois, Robin; Guisse, A.; Sall, Saïdou; Chotte, Jean-Luc; Thioulouse, J.

    2006-01-01

    The leaf litter of six tropical tree species (Acacia holosericea, Acacia tortilis, Azadirachta indica, Casuarina equisetifolia, Cordyla pinnata and Faidherbia albida) frequently used in agroforestry plantations in Sahelian and Soudano-Sahelian areas were tested for their influence on soil nitrogen content, microbial biomass and plant growth under controlled greenhouse conditions. Half of the soil was planted with onion (Allium cepa L.) seedlings and the other half was not. Two herbaceous spec...

  9. Combined Plate Microbial Assay (CPMA): a 6-plate-method for simultaneous first and second level screening of antibacterial residues in meat.

    Science.gov (United States)

    Ferrini, A M; Mannoni, V; Aureli, P

    2006-01-01

    This paper proposes an improved high throughput microbial method for the simultaneous performance of first and second level screening for antibacterial residues in meat. It is based on growth inhibition of B. subtilis on agar medium pH 6, 7.2 and 8, of B. cereus on agar medium pH 5.9, of M. luteus on agar medium pH 8 and of E. coli on agar medium pH 7.2 (research or first level screening) and on the use of confirmatory solutions (Pase, Paba, MgSO4) for the identification or second level screening. In kidney control samples, dialysis membranes were interposed between samples and the agar surface to both prevent the action of lysozyme and reduce false positive results. The proposed method detects beta-lactams, sulfonamides, tetracyclines, aminoglycosides, macrolides and quinolones at MRL concentrations and reliably indicates the inhibitor family. Results are obtained in 18-24 h.

  10. Nano-scale investigation of the association of microbial nitrogen residues with iron (hydr)oxides in a forest soil O-horizon

    Science.gov (United States)

    Keiluweit, Marco; Bougoure, Jeremy J.; Zeglin, Lydia H.; Myrold, David D.; Weber, Peter K.; Pett-Ridge, Jennifer; Kleber, Markus; Nico, Peter S.

    2012-10-01

    Amino sugars in fungal cell walls (such as chitin) represent an important source of nitrogen (N) in many forest soil ecosystems. Despite the importance of this material in soil nitrogen cycling, comparatively little is known about abiotic and biotic controls on and the timescale of its turnover. Part of the reason for this lack of information is the inaccessibility of these materials to classic bulk extraction methods. To address this issue, we used advanced visualization tools to examine transformation pathways of chitin-rich fungal cell wall residues as they interact with microorganisms, soil organic matter and mineral surfaces. Our goal was to document initial micro-scale dynamics of the incorporation of 13C- and 15N-labeled chitin into fungi-dominated microenvironments in O-horizons of old-growth forest soils. At the end of a 3-week incubation experiment, high-resolution secondary ion mass spectrometry imaging of hyphae-associated soil microstructures revealed a preferential association of 15N with Fe-rich particles. Synchrotron-based scanning transmission X-ray spectromicroscopy (STXM/NEXAFS) of the same samples showed that thin organic coatings on these soil microstructures are enriched in aliphatic C and amide N on Fe (hydr)oxides, suggesting a concentration of microbial lipids and proteins on these surfaces. A possible explanation for the results of our micro-scale investigation of chemical and spatial patterns is that amide N from chitinous fungal cell walls was assimilated by hyphae-associated bacteria, resynthesized into proteinaceous amide N, and subsequently concentrated onto Fe (hydr)oxide surfaces. If confirmed in other soil ecosystems, such rapid association of microbial N with hydroxylated Fe oxide surfaces may have important implications for mechanistic models of microbial cycling of C and N.

  11. Preservatives and neutralizing substances in milk: analytical sensitivity of official specific and nonspecific tests, microbial inhibition effect, and residue persistence in milk

    Directory of Open Access Journals (Sweden)

    Livia Cavaletti Corrêa da Silva

    2015-09-01

    Full Text Available Milk fraud has been a recurring problem in Brazil; thus, it is important to know the effect of most frequently used preservatives and neutralizing substances as well as the detection capability of official tests. The objective of this study was to evaluate the analytical sensitivity of legislation-described tests and nonspecific microbial inhibition tests, and to investigate the effect of such substances on microbial growth inhibition and the persistence of detectable residues after 24/48h of refrigeration. Batches of raw milk, free from any contaminant, were divided into aliquots and mixed with different concentrations of formaldehyde, hydrogen peroxide, sodium hypochlorite, chlorine, chlorinated alkaline detergent, or sodium hydroxide. The analytical sensitivity of the official tests was 0.005%, 0.003%, and 0.013% for formaldehyde, hydrogen peroxide, and hypochlorite, respectively. Chlorine and chlorinated alkaline detergent were not detected by regulatory tests. In the tests for neutralizing substances, sodium hydroxide could not be detected when acidity was accurately neutralized. The yogurt culture test gave results similar to those obtained by official tests for the detection of specific substances. Concentrations of 0.05% of formaldehyde, 0.003% of hydrogen peroxide and 0.013% of sodium hypochlorite significantly reduced (P

  12. Potato Starch Residue as a Substrate for Microbial Fermentation%利用微生物发酵马铃薯淀粉渣的研究进展

    Institute of Scientific and Technical Information of China (English)

    雷恒; 曹兵海; 杨富裕; 徐春城

    2011-01-01

    生物技术的进步为马铃薯淀粉渣等食品工业加工副产品的有效利用提供了新的技术手段.马铃薯淀粉渣是马铃薯淀粉生产过程中产生的主要副产物,因其蛋白质含量较低,纤维素、半纤维素和果胶等含量高,所以作为动物饲料利用时营养价值较低.马铃薯淀粉渣来源丰富,可作为微生物发酵生产诸如酶、蛋白质饲料、有机酸以及膳食纤维等高附加值产品的理想基质.发酵技术用于马铃薯淀粉渣的生物转化备受人们的关注,微生物预处理过程不仅改进了底物的利用,而且能解决废弃物带来的环境污染问题.本文综述了近期通过生物技术手段开发马铃薯淀粉渣的高附加值产品及其工艺的研究进展.%Potato starch residue is the major by-product of the potato starch processing industry. It has low nutritive value because of its low protein content and high amounts of cellulose, hemicelluloses and pectin. Due to the abundant output of by-product, it can be used as an ideal substrate for microbial fermentation to product value-added products such as enzyme preparation, protein-enriched animal feed, organic acid and dietary fiber etc. Application of microbial fermentation technology can be an attractive possibility for such bioconversions. The processing by microbial fermentation has not only improving substrate utilization, but also helping to solve environmental pollution problems. This article reviews the recent research progress on the development of value-added products and techniques of potato starch residue by biotechnological means.

  13. The Influence of Multiwalled Carbon Nanotubes on Polycyclic Aromatic Hydrocarbon (PAH) Bioavailability and Toxicity to Soil Microbial Communities in Alfalfa Rhizosphere

    Science.gov (United States)

    Carbon nanotubes (CNTs) may affect bioavailability and toxicity of organic contaminants due to their adsorption properties. Recent studies have observed the influence of multiwalled carbon nanotubes (MWNTs) on the fate of polycyclic aromatic hydrocarbons (PAHs) and other organic contaminants. Greenh...

  14. 硫丹残留及其微生物降解研究进展%Advance on Endosulfan Residue and its Microbial Degration

    Institute of Scientific and Technical Information of China (English)

    竺利红

    2011-01-01

    Endosulfan, a chlorinated pesticide of the cyclodiene group, is used extensively for the protection of cotton, tea and sugarcane crops. Endosulfan residue has led to the contamination of soil and water environments. It is also a serious threat to human and animal health. The toxicity, application situation and residue of endosulfan were introduced briefly. The residue causes were analyzed too. The degradation of pesticides in soil by microorganism was an effective method. The types of microorganism which degraded endosulfan, the mechanism of degradation were summarized in this paper. To realize a practical application of endosulfan-degrading microorganisms on fields, isolation of highly efficient degrading microorganisms, construction of genetically engineered microorganisms, environmental microbial ecosystem of degrading microorganisms should be enhanced.%硫丹是一种广泛应用的有机氯杀虫剂,其残留已造成了严重的环境污染,威胁着人类和动物的健康.简述了硫丹的毒性、应用概况及引起的残留现状,并分析了引起硫丹残留的主要原因.利用微生物降解土壤中残留的农药是一种非常有效的方法.回顾了国内外利用微生物降解硫丹的研究进展,包括降解菌种类和作用机理.为使硫丹降解菌真正实现应用,指出了今后应加强高效降解菌的筛选、工程菌的构建、降解菌在污染土壤环境中的微生态学等方面的研究.

  15. Kinetics of petroleum hydrocarbon degradation in soil and diversity of microbial community during composting%石油烃类污染物降解动力学和微生物群落多样性分析

    Institute of Scientific and Technical Information of China (English)

    甄丽莎; 谷洁; 胡婷; 刘晨; 贾凤安; 吕睿

    2015-01-01

    为了探讨不同初始浓度石油污染土壤堆腐化修复机制,以石油降解菌剂和腐熟鸡粪为调理剂,研究了初始浓度分别为5000(T1)、10000(T2)和50000 mg/kg(T3)的石油污染土壤堆腐化修复过程石油烃类污染物降解动力学特征和微生物群落多样性。结果表明:堆腐化修复过程石油烃类污染物降解符合一级反应动力学,反应常数分别为0.012、0.094和0.050 d-1,半衰期分别为6.79、7.37和13.86 d。整个堆腐过程石油烃类污染物平均降解速率分别为112.08、230.05和887.93 mg/(kg·d)。3个处理的孔平均颜色变化率(average well color development)和碳源利用率(除芳香烃类化合物外)随堆腐进程的推进逐渐升高,在堆腐中、后期达到最大,T3处理显著高于T1、T2处理。多聚物类和糖类代谢群是堆腐体系中的优势菌群。主成分分析表明3个处理的微生物群落差异显著(除第9天外),起分异作用的碳源主要是糖类和羧酸类。微生物群落的丰富度指数和均一度指数随堆腐进程的推进逐渐升高并在堆腐后期达到最大,与T1处理相比, T3处理分别高了0.21%和17.64%,差异达到显著水平(P0.05)。堆肥结束时3个处理的种子发芽指数(seed germination index, SGI)分别比堆腐初期提高了18.26%、20.42%和36.41%。该研究结果为黄土高原不同程度石油污染土壤堆腐化修复的应用提供参考依据和理论基础。%In order to investigate the mechanism of bioremediation of petroleum hydrocarbon-contaminated soil by composting, an experiment was conducted with bacteria agent and mature chicken manure as amendment. We studied the kinetics of petroleum hydrocarbon degradation and the diversity of microbial community during the bioremediation of petroleum hydrocarbon-contaminated soil by composting with different concentrations. The concentrations included 5 000 mg/kg (T1), 10 000 mg/kg (T2

  16. Assessing fuel spill risks in polar waters: Temporal dynamics and behaviour of hydrocarbons from Antarctic diesel, marine gas oil and residual fuel oil.

    Science.gov (United States)

    Brown, Kathryn E; King, Catherine K; Kotzakoulakis, Konstantinos; George, Simon C; Harrison, Peter L

    2016-09-15

    As part of risk assessment of fuel oil spills in Antarctic and subantarctic waters, this study describes partitioning of hydrocarbons from three fuels (Special Antarctic Blend diesel, SAB; marine gas oil, MGO; and intermediate grade fuel oil, IFO 180) into seawater at 0 and 5°C and subsequent depletion over 7days. Initial total hydrocarbon content (THC) of water accommodated fraction (WAF) in seawater was highest for SAB. Rates of THC loss and proportions in equivalent carbon number fractions differed between fuels and over time. THC was most persistent in IFO 180 WAFs and most rapidly depleted in MGO WAF, with depletion for SAB WAF strongly affected by temperature. Concentration and composition remained proportionate in dilution series over time. This study significantly enhances our understanding of fuel behaviour in Antarctic and subantarctic waters, enabling improved predictions for estimates of sensitivities of marine organisms to toxic contaminants from fuels in the region.

  17. Polycyclic aromatic hydrocarbon body residues and lysosomal membrane destabilization in mussels exposed to the Dubai Star bunker fuel oil (intermediate fuel oil 380) spill in San Francisco Bay.

    Science.gov (United States)

    Hwang, Hyun-Min; Stanton, Beckye; McBride, Toby; Anderson, Michael J

    2014-05-01

    Following the spill of bunker fuel oil (intermediate fuel oil 380, approximately 1500-3000 L) into San Francisco Bay in October 2009, polycyclic aromatic hydrocarbon (PAH) concentrations in mussels from moderately oiled areas increased up to 87 554 ng/g (dry wt) and, 3 mo later, decreased to concentrations found in mussels collected prior to oiling, with a biological half-life of approximately 16 d. Lysosomal membrane destabilization increased in mussels with higher PAH body burdens.

  18. Effect of various amendments on heavy mineral oil bioremediation and soil microbial activity.

    Science.gov (United States)

    Lee, Sang-Hwan; Oh, Bang-Il; Kim, Jeong-gyu

    2008-05-01

    To examine the effects of amendments on the degradation of heavy mineral oil, we conducted a pilot-scale experiment in the field for 105 days. During the experiment, soil samples were collected and analyzed periodically to determine the amount of residual hydrocarbons and evaluate the effects of the amendments on microbial activity. After 105 days, the initial level of contamination (7490+/-480 mg hydrocarbon kg(-1) soil) was reduced by 18-40% in amended soils, whereas it was only reduced by 9% in nonamended soil. Heavy mineral oil degradation was much faster and more complete in compost-amended soil than in hay-, sawdust-, and mineral nutrient-amended soils. The enhanced degradation of heavy mineral oil in compost-amended soil may be a result of the significantly higher microbial activity in this soil. Among the studied microbial parameters, soil dehydrogenase, lipase, and urease activities were strongly and negatively correlated with heavy mineral oil biodegradation (Pamended soil.

  19. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  20. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Science.gov (United States)

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  1. 利用醋渣生产微生物发酵饲料的研究%Study on Microbial Fermentation Feed Produced by Vinegar Residue

    Institute of Scientific and Technical Information of China (English)

    徐秀梅

    2013-01-01

    Vinegar residue is used as main raw material; wheat bran,corn steep liquor,urea and ammonium sulfate are used as supplementary materials.Candida utilis,saccharomyces cerevisiae and trichoderma harziamum are used by mixed fermentation to produce microbial fermentation feed.The results show that the nutrition value of feed improves obviously after fermentation; the content of true protein in feed increases more than 15%,the degradation rate of cellulose exceeds 25%.%以醋渣为主要原料,以麸皮、玉米浆、尿素、硫酸铵等为辅料,利用产朊假丝酵母、酿酒酵母和长柄木霉混合发酵生产微生物发酵饲料,结果表明:发酵后的饲料综合营养价值明显提高,饲料中真蛋白含量提高15%以上,纤维素降解率超过25%.

  2. A survey of microbial community diversity in marine sediments impacted by petroleum hydrocarbons from the Gulf of Mexico and Atlantic shorelines, Texas to Florida

    Science.gov (United States)

    Lisle, John T.; Stellick, Sarah H.

    2011-01-01

    Microbial community genomic DNA was extracted from sediment samples collected along the Gulf of Mexico and Atlantic coasts from Texas to Florida. Sample sites were identified as being ecologically sensitive and (or) as having high potential of being impacted by Macondo-1 (M-1) well oil from the Deepwater Horizon blowout. The diversity within the microbial communities associated with the collected sediments provides a baseline dataset to which microbial community-diversity data from impacted sites could be compared. To determine the microbial community diversity in the samples, genetic fingerprints were generated and compared. Specific sequences within the community genomic DNA were first amplified using the polymerase chain reaction (PCR) with a primer set that provides possible resolution to the species level. A second nested PCR was performed on the primary PCR products using a primer set on which a GC-clamp was attached to one of the primers. The nested PCR products were separated using denaturing-gradient gel electrophoresis (DGGE) that resolves the nested PCR products based on sequence dissimilarities (or similarities), forming a genomic fingerprint of the microbial diversity within the respective samples. Samples with similar fingerprints were grouped and compared to oil-fingerprint data from the same sites (Rosenbauer and others, 2011). The microbial community fingerprints were generally grouped into sites that had been shown to contain background concentrations of non-Deepwater Horizon oil. However, these groupings also included sites where no oil signature was detected. This report represents some of the first information on naturally occurring microbial communities in sediment from shorelines along the Gulf of Mexico and Atlantic coasts from Texas to Florida.

  3. 玉米和大豆秸秆还田对黑土微生物量及呼吸的影响%Effects of Corn and Soybean Residues Return on Microbial Biomass and Respiration in a Black Soil

    Institute of Scientific and Technical Information of China (English)

    刘四义; 贾淑霞; 张晓平; 陈学文; 张士秀; 孙冰洁; 陈升龙; 窦永静

    2014-01-01

    土壤微生物量和呼吸对秸秆还田后的分解转化及碳固存效果有着显著的响应。为了探明在还田条件下,不同类型秸秆及其碳氮含量对土壤微生物量和呼吸的影响,研究将玉米和大豆不同植株部位秸秆与耕层黑土混合,置于25℃恒温条件下培养61 d。在第61 d测定土壤的微生物量碳( MBC)、微生物量氮( MBN)、矿质态氮和微生物呼吸速率,并分析比较它们在不同处理中的差异及其与秸秆C、 N含量之间的相互关系。结果显示,不同类型秸秆添加下的土壤MBC大小表现为:大豆根>玉米茎下部>大豆茎>玉米叶>玉米茎顶部>玉米根>大豆叶,土壤MBN的大小表现为:玉米茎下部>玉米叶>大豆根>玉米根>玉米茎顶部>大豆茎>大豆叶。除大豆叶外,其它处理的土壤MBC/MBN均显著小于空白处理。秸秆含碳量与MBC、 MBN、 MBC/MBN、微生物呼吸速率、呼吸熵之间均有显著的相关关系,而秸秆含碳量与土壤矿质氮含量之间有极显著的负相关关系。土壤MBC、微生物呼吸速率、微生物呼吸熵均与秸秆含氮量呈明显负相关关系。不同秸秆添加下的微生物呼吸速率和呼吸熵的大小表现基本一致,且呼吸速率、呼吸熵两者之间具有极显著的相关关系。大豆茎、大豆叶的呼吸速率和呼吸熵显著大于玉米秸秆2倍左右。研究说明秸秆还田促进了细菌、放线菌等C/N较低的微生物生长繁殖,含氮量高的秸秆不利于还田后期微生物生物量、微生物呼吸速率及活性的保持,土壤微生物活性比微生物量对秸秆分解、微生物呼吸速率的影响更大。图1,表3,参33。%Soil microbial biomass play an important role in the decomposition and transformation of residues returned to soil .In order to evaluate the effects of residue types and its carbon and nitrogen concentration on soil microbial biomass and

  4. Insights into the biodegradation of weathered hydrocarbons in contaminated soils by bioaugmentation and nutrient stimulation.

    Science.gov (United States)

    Jiang, Ying; Brassington, Kirsty J; Prpich, George; Paton, Graeme I; Semple, Kirk T; Pollard, Simon J T; Coulon, Frédéric

    2016-10-01

    The potential for biotransformation of weathered hydrocarbon residues in soils collected from two commercial oil refinery sites (Soil A and B) was studied in microcosm experiments. Soil A has previously been subjected to on-site bioremediation and it was believed that no further degradation was possible while soil B has not been subjected to any treatment. A number of amendment strategies including bioaugmentation with hydrocarbon degrader, biostimulation with nutrients and soil grinding, were applied to the microcosms as putative biodegradation improvement strategies. The hydrocarbon concentrations in each amendment group were monitored throughout 112 days incubation. Microcosms treated with biostimulation (BS) and biostimulation/bioaugmentation (BS + BA) showed the most significant reductions in the aliphatic and aromatic hydrocarbon fractions. However, soil grinding was shown to reduce the effectiveness of a nutrient treatment on the extent of biotransformation by up to 25% and 20% for the aliphatic and aromatic hydrocarbon fractions, respectively. This is likely due to the disruption to the indigenous microbial community in the soil caused by grinding. Further, ecotoxicological responses (mustard seed germination and Microtox assays) showed that a reduction of total petroleum hydrocarbon (TPH) concentration in soil was not directly correlable to reduction in toxicity; thus monitoring TPH alone is not sufficient for assessing the environmental risk of a contaminated site after remediation.

  5. White spruce response to co-composted hydrocarbon-contaminated drilling waste: effects of compost age and nitrogen fertilization.

    Science.gov (United States)

    Choi, Woo-Jung; Chang, Scott X; Hao, Xiying

    2005-01-01

    There are growing interests to use co-composted drilling wastes contaminated with hydrocarbons as growth media for planting in land reclamation. However, such use of the compost may have potential problems such as inherent toxicity of residual hydrocarbon and microbial N immobilization due to high compost C to N ratios. We investigated the growth, biomass production, N uptake, and foliar delta13C of white spruce (Picea glauca [Moench] Voss) seedlings in a pot experiment using 1-, 2-, 3-, and 4-yr-old composts (with different hydrocarbon concentrations and C to N ratios) and a local noncontaminated soil with (200 kg N ha(-1)) or without N fertilization. Growth and N content of seedlings (particularly N content in roots) were lower when grown in the compost media as compared with those grown in the soil. Within the compost treatments seedling growth was affected by compost age, but the magnitude of growth reduction was not linearly proportional to hydrocarbon concentrations. Plant N uptake increased with compost age, which corresponds with an increase in indigenous mineral N concentration. Effects of N fertilization on N uptake were curtailed by the presence of indigenous mineral N (e.g., in the 4-yr-old compost) and by fertilization-induced stimulation of microbial activities (e.g., in the 1-yr-old compost). The differences in foliar delta13C values between seedlings grown in compost and soil (P < 0.05) suggest that limitations on water uptake caused by the residual hydrocarbon might have been the predominant factor limiting seedling growth in the compost media. This study suggests that water stress caused by residual hydrocarbons may be a critical factor for the successful use of co-composted drilling wastes as a growth medium.

  6. Phytoremediation of polyaromatic hydrocarbons, anilines and phenols.

    Science.gov (United States)

    Harvey, Patricia J; Campanella, Bruno F; Castro, Paula M L; Harms, Hans; Lichtfouse, Eric; Schäffner, Anton R; Smrcek, Stanislav; Werck-Reichhart, Daniele

    2002-01-01

    Phytoremediation technologies based on the combined action of plants and the microbial communities that they support within the rhizosphere hold promise in the remediation of land and waterways contaminated with hydrocarbons but they have not yet been adopted in large-scale remediation strategies. In this review plant and microbial degradative capacities, viewed as a continuum, have been dissected in order to identify where bottle-necks and limitations exist. Phenols, anilines and polyaromatic hydrocarbons (PAHs) were selected as the target classes of molecule for consideration, in part because of their common patterns of distribution, but also because of the urgent need to develop techniques to overcome their toxicity to human health. Depending on the chemical and physical properties of the pollutant, the emerging picture suggests that plants will draw pollutants including PAHs into the plant rhizosphere to varying extents via the transpiration stream. Mycorrhizosphere-bacteria and -fungi may play a crucial role in establishing plants in degraded ecosystems. Within the rhizosphere, microbial degradative activities prevail in order to extract energy and carbon skeletons from the pollutants for microbial cell growth. There has been little systematic analysis of the changing dynamics of pollutant degradation within the rhizosphere; however, the importance of plants in supplying oxygen and nutrients to the rhizosphere via fine roots, and of the beneficial effect of microorganisms on plant root growth is stressed. In addition to their role in supporting rhizospheric degradative activities, plants may possess a limited capacity to transport some of the more mobile pollutants into roots and shoots via fine roots. In those situations where uptake does occur (i.e. only limited microbial activity in the rhizosphere) there is good evidence that the pollutant may be metabolised. However, plant uptake is frequently associated with the inhibition of plant growth and an

  7. Modified a colony forming unit microbial adherence to hydrocarbons assay and evaluated cell surface hydrophobicity and biofilm production of Vibrio scophthalmi

    Science.gov (United States)

    Vibrio scophthalmi has been considered as an opportunistic pathogen of the flat fish. There is little information available on V. scophthalmi adhesion to the host, an important step in the initial infection process. The objectives of this study were to (1) develop a modified Microbial Adherence to H...

  8. Factors Affccting Change of Microbial Community During Plant Residue Decomposition: A Review%植物残体分解过程中微生物群落变化影响因素研究进展

    Institute of Scientific and Technical Information of China (English)

    王晓玥; 孙波

    2012-01-01

    Plant residues are an important source of soil organic matter. An increasing attention has been paid on the succession^ pattern of microbial community structure during decomposition of plant residues. In this article, it is reviewed factors that have significant influence on the microbial community structure and function. These factors mainly include properties of plant residue, soil and climate factors and agricultural practices, which affect diversity of microbial community through influences on both activities of microbe and chemical composition changes of plant residue during its decomposition process. The impacts of these factors are not isolated, but interrelated and conditioned. In addition, microbial communities have shown obvious patterns with decomposition of residues. Furthermore, profoundly researches, especially under field conditions, are needed on successional pattern of key microbial community as well as interaction mechanism of different factors.%植物残体是土壤有机质的重要来源,研究分解植物残体的微生物群落结构及其演替规律日益受到重视.本文综述了影响植物残体分解过程中微生物群落结构和功能变化的3个主要因素;植物残体的性质、土壤和气候环境因素、农艺措施,这些因素通过影响微生物本身的活性和植物残体分解过程中化学组成的变化从而导致微生物群落的变化,同时植物残体腐解过程中微生物群落存在明显的演替现象.以上因素的影响并不是孤立的,而是相互联系和制约的.未来针对野外田问条件下植物残体的分解过程,仍需深入研究关键微生物群落的演替规律以及不同影响因素的交互作用机制.

  9. Effects of Different Water Seasons on the Residual Characteristics and Ecological Risk of Polycyclic Aromatic Hydrocarbons in Sediments from Changdang Lake, China

    Directory of Open Access Journals (Sweden)

    Javid Hussain

    2016-01-01

    Full Text Available The sediments’ samples were collected from Changdang Lake for the concentration of fourteen polycyclic aromatic hydrocarbons in March (dry season, June (wet season, and September (temperate season 2013. The highest average value of ∑PAHs was detected as 295.28 ng/g dw in March, followed by 240.91 ng/g dw in June and 165.81 ng/g dw in September. Source characterization studies based on the analysis of diagnostic ratio (triangular plot method suggested that the PAHs in sediments from Changdang Lake were mainly from the mixed combustion source of biomass and petroleum, and the origins of PAHs in different sampling sites have a great deal of temporal and spatial variability during different water seasons. Redundancy analysis was applied to identify the impact factors and the possible relationship between PAHs and environmental parameters. The predicted results showed that the main factors impacting PAHs temporal distribution were temperature, dissolved oxygen, pH, and oxidation-reduction potential, while conductivity showed secondary impacts on the PAHs distribution. Risk assessment of PAHs in sediments was carried out based on the US Sediments Quality Guidelines (SQGs. By comparing the present study results with SQGs standard values results showed that the adverse effects are not expected at the present levels of PAHs contamination observed in the sediments from Changdang Lake.

  10. Application of a continuously stirred tank bioreactor (CSTR) for bioremediation of hydrocarbon-rich industrial wastewater effluents

    Energy Technology Data Exchange (ETDEWEB)

    Gargouri, Boutheina; Karray, Fatma; Mhiri, Najla; Aloui, Fathi [Laboratoire des Bioprocedes Environnementaux, Pole d' Excellence Regional AUF-LBPE, Centre de Biotechnologie de Sfax, Universite de Sfax, BP 1117, 3018 Sfax (Tunisia); Sayadi, Sami, E-mail: sami.sayadi@cbs.rnrt.tn [Laboratoire des Bioprocedes Environnementaux, Pole d' Excellence Regional AUF-LBPE, Centre de Biotechnologie de Sfax, Universite de Sfax, BP 1117, 3018 Sfax (Tunisia)

    2011-05-15

    A continuously stirred tank bioreactor (CSTR) was used to optimize feasible and reliable bioprocess system in order to treat hydrocarbon-rich industrial wastewaters. A successful bioremediation was developed by an efficient acclimatized microbial consortium. After an experimental period of 225 days, the process was shown to be highly efficient in decontaminating the wastewater. The performance of the bioaugmented reactor was demonstrated by the reduction of COD rates up to 95%. The residual total petroleum hydrocarbon (TPH) decreased from 320 mg TPH l{sup -1} to 8 mg TPH l{sup -1}. Analysis using gas chromatography-mass spectrometry (GC-MS) identified 26 hydrocarbons. The use of the mixed cultures demonstrated high degradation performance for hydrocarbons range n-alkanes (C10-C35). Six microbial isolates from the CSTR were characterized and species identification was confirmed by sequencing the 16S rRNA genes. The partial 16S rRNA gene sequences demonstrated that 5 strains were closely related to Aeromonas punctata (Aeromonas caviae), Bacillus cereus, Ochrobactrum intermedium, Stenotrophomonas maltophilia and Rhodococcus sp. The 6th isolate was affiliated to genera Achromobacter. Besides, the treated wastewater could be considered as non toxic according to the phytotoxicity test since the germination index of Lepidium sativum ranged between 57 and 95%. The treatment provided satisfactory results and presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.

  11. Application of a continuously stirred tank bioreactor (CSTR) for bioremediation of hydrocarbon-rich industrial wastewater effluents.

    Science.gov (United States)

    Gargouri, Boutheina; Karray, Fatma; Mhiri, Najla; Aloui, Fathi; Sayadi, Sami

    2011-05-15

    A continuously stirred tank bioreactor (CSTR) was used to optimize feasible and reliable bioprocess system in order to treat hydrocarbon-rich industrial wastewaters. A successful bioremediation was developed by an efficient acclimatized microbial consortium. After an experimental period of 225 days, the process was shown to be highly efficient in decontaminating the wastewater. The performance of the bioaugmented reactor was demonstrated by the reduction of COD rates up to 95%. The residual total petroleum hydrocarbon (TPH) decreased from 320 mg TPH l(-1) to 8 mg TPH l(-1). Analysis using gas chromatography-mass spectrometry (GC-MS) identified 26 hydrocarbons. The use of the mixed cultures demonstrated high degradation performance for hydrocarbons range n-alkanes (C10-C35). Six microbial isolates from the CSTR were characterized and species identification was confirmed by sequencing the 16S rRNA genes. The partial 16S rRNA gene sequences demonstrated that 5 strains were closely related to Aeromonas punctata (Aeromonas caviae), Bacillus cereus, Ochrobactrum intermedium, Stenotrophomonas maltophilia and Rhodococcus sp. The 6th isolate was affiliated to genera Achromobacter. Besides, the treated wastewater could be considered as non toxic according to the phytotoxicity test since the germination index of Lepidium sativum ranged between 57 and 95%. The treatment provided satisfactory results and presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.

  12. Effect of cyclodextrin and transformer oil amendments on the chemical extractability of aged [14C]polychlorinated biphenyl and [14C]polycyclic aromatic hydrocarbon residues in soil.

    Science.gov (United States)

    Doick, Kieron J; Burauel, Peter; Jones, Kevin C; Semple, Kirk T

    2005-09-01

    Sequestration of hydrophobic organic contaminants (HOCs) in soils limits chemical and biological availability. Concerns exist regarding the long-term stability of sequestered contaminants in the environment, and stability needs to be demonstrated if bioavailability considerations are to be adopted into the risk assessment and remediation of contaminated land. The aim of the present study was to test the short-term influence of two organic amendments on the chemical extractability of HOC residues that had been present in soils for more than 12 years. The amendments investigated were cyclodextrin and transformer oil (a light, nonaqueous phase liquid [LNAPL]). The contaminants investigated were fluoranthene and benzo[a]pyrene in one soil and the polychlorinated biphenyls (PCBs) 28 and 52 in a second soil. The addition of cyclodextrin to the soils did not result in a significant increase in chemical extractability of the residues after a 36-d contact time. The addition of transformer oil resulted in an increase in chemical extractability of the PCBs after a 14-d soil-LNAPL contact time and a further increase after a 36-d contact time. The present study demonstrates that the chemical availability of aged HOCs in soil may be influenced by the presence of other chemicals and has implications for the long-term management of contaminated land.

  13. Formation and destruction of Polycyclic Aromatic Hydrocarbons (PAHs in the flaring of the biogas collected from an automotive shredded residues landfill

    Directory of Open Access Journals (Sweden)

    Massimo Raboni

    2016-03-01

    Full Text Available The paper shows the results of the combustion in an enclosed flare of the biogas collected from an automotive shredded residues landfill. The results demonstrate that at 1,000°C and long combustion, several synthesis reactions lead to the formation of 4 to 6 rings of PAHs. This formation also involves the formation of compounds such as benzo(g,h,iperylene, indeno(1,2,3-cdpyrene and dibenzo(a,hanthracene not present in raw biogas. However, the compounds most likely to form in combustion are benzo (a anthracene and benzo (b fluoranthene. The only exception is chrysene which is significantly destroyed. The experience has proved the total lack of formation of PAHs with only 2 and 3 aromatic rings.

  14. IODP Expedition 337: Deep Coalbed Biosphere off Shimokita - Microbial processes and hydrocarbon system associated with deeply buried coalbed in the ocean

    Science.gov (United States)

    Inagaki, Fumio; Hinrichs, Kai-Uwe; Kubo, Yusuke; IODP Expedition 337 Scientists

    2016-06-01

    The Integrated Ocean Drilling Program (IODP) Expedition 337 was the first expedition dedicated to subseafloor microbiology that used riser-drilling technology with the drilling vessel Chikyu. The drilling Site C0020 is located in a forearc basin formed by the subduction of the Pacific Plate off the Shimokita Peninsula, Japan, at a water depth of 1180 m. Primary scientific objectives during Expedition 337 were to study the relationship between the deep microbial biosphere and a series of ˜ 2 km deep subseafloor coalbeds and to explore the limits of life in the deepest horizons ever probed by scientific ocean drilling. To address these scientific objectives, we penetrated a 2.466 km deep sedimentary sequence with a series of lignite layers buried around 2 km below the seafloor. The cored sediments, as well as cuttings and logging data, showed a record of dynamically changing depositional environments in the former forearc basin off the Shimokita Peninsula during the late Oligocene and Miocene, ranging from warm-temperate coastal backswamps to a cool water continental shelf. The occurrence of small microbial populations and their methanogenic activity were confirmed down to the bottom of the hole by microbiological and biogeochemical analyses. The factors controlling the size and viability of ultra-deep microbial communities in those warm sedimentary habitats could be the increase in demand of energy and water expended on the enzymatic repair of biomolecules as a function of the burial depth. Expedition 337 provided a test ground for the use of riser-drilling technology to address geobiological and biogeochemical objectives and was therefore a crucial step toward the next phase of deep scientific ocean drilling.

  15. Biodegradation of Hydrocarbons within the Water Column and Marsh Sediments following the Deepwater Horizon Accident

    Science.gov (United States)

    Atlas, R.; Cook, L.; Murray, K.; Cerrito, K.; Faith, S.; Boehm, P.

    2012-12-01

    Physical and chemical dispersion of oil released from the Deepwater Horizon spill between April 20 and July 15, 2010 resulted in fine droplets and dissolved hydrocarbons moving away from the wellhead within the water column. Both alkanes and polycyclic aromatic hydrocarbons were rapidly biodegraded as evidenced by detailed chemistry measurements using GC and GC-MS analyses of over 10,000 water samples. During the release (April-July), concentrations of polycyclic aromatic hydrocarbons (PAH) attenuated rapidly with distance from the release point (the wellhead) and were seen to reach biodegradation. Loss of total and high molecular weight alkanes and PAH relative to the conserved biomarker hopane also showed that there was extensive hydrocarbon biodegradation. Shortly after the well was capped most of the hydrocarbons in the deepwater had been biodegraded to levels below analytical detection limits. Clearly microbial biodegradation of the oil within the water column removed many of the toxic components and reduced the overall impact of the oil released from the well. Oil that reached the water surface and formed slicks was less extensively biodegraded by microbes as it moved toward the shorelines. A study of impacted Louisiana coastal marshes 1 year later, however, showed that residual oil was very highly weathered with losses of alkanes and PAHs in the MC252 oiled sediment samples. Where sufficient oil was present for detailed chemical analyses changes in C17/pristine, C18/phytane, C2phenanthrene/C2dibenzothiophene, C3phenanthrene/C3dibenzothiophene, total polycyclic aromatics to hopane, and total heavy polycyclic aromatics (4-6 rings) to hopane showed evidence for extensive biodegradation. Molecular analyses performed with PhyloChip, GeoChip and whole metagenome sequencing confirmed that microbial populations in marsh sediments were capable of hydrocarbon biodegradation.

  16. Effects of Temperature Changes on Biodegradation of Petroleum Hydrocarbons in Contaminated Soils from an Arctic Site

    Science.gov (United States)

    Chang, W.; Klemm, S.; Whyte, L.; Ghoshal, S.

    2009-05-01

    identified through 16S rRNA gene sequence analyses. Under the seasonal freeze-thaw conditions, microbial activity and hydrocarbon degradation was detected even when soils were frozen. The microbial activity was significantly correlated to residual unfrozen water contents.

  17. Microbial and molecular techniques to evaluate and to implement in-situ biodegradation potential and activity at sites contaminated with aromatic and chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Karg, F. [HPC Envirotec / France and HPC AG (Germany); Henkler, Ch. [Planreal (Switzerland)

    2005-07-01

    Intrinsic bio-remediation harnesses the ability of indigenous microorganisms to degrade contaminants that are present in soil and groundwater. Over the past decade many environmental regulatory agencies especially in Europe have come to recognize the importance of these natural processes in contaminant attenuation. In order to use in-situ bio-remediation to clean up a site successfully it is necessary to investigate the indigenous microbial population and its potential activity to degrade the contaminants of concern (COCs). The evaluation of naturally-occurring degradative activity in initial screening of soil and groundwater samples using recently developed molecular and microbial methods may allow for the implementation of a contaminant reduction and management program without the need for fully engineered remediation intervention. Limited engineering approaches (nutrient delivery etc.) can be implemented to support naturally-occurring bio-restoration processes to achieve a controlled, dynamic attenuation of COCs. Techniques for monitoring pollutant-degrading microorganisms were previously limited to standard culturing techniques. More recently, techniques based upon detection of genetic elements and metabolic activities have been developed in collaboration with university partners Europe, especially in France. The modern techniques are more sensitive for monitoring microbial populations, metabolic activity and the genetic potential to degrade the COCs, and avoid the need for cultivation of microbes under artificial conditions in the laboratory. Especially the application of PCR-Tests (Polymerase Chain Reaction) are able to quantify the Genetic Potential of Pollutant Microbiological Degradation on a contaminated site. This enables to use very economic in-situ site rehabilitation strategies as for example (Dynamic Natural Attenuation). For this modern application of these new strategies PLANREAL created with HPC Envirotec and together with a French University

  18. BIODEGRADASI RESIDU TOTAL PETROLEUM HIDROKARBON DI BAWAH KONSENTRASI 1% (W/W HASIL PROSES BIOREMEDIASI (Biodegradation of Total Petroleum Hydrocarbons Residues below 1% Concentration (W/W Using Bioremediation Process

    Directory of Open Access Journals (Sweden)

    Allen Kurniawan

    2015-01-01

    Full Text Available ABSTRAK Sektor pertambangan minyak bumi dan gas cenderung menghasilkan limbah yang dipersepsikan sebagai salah satu sumber pencemaran lingkungan. Menurut Keputusan Menteri Lingkungan Hidup Nomor 128/2003, proses bioremediasi merupakan teknologi alternatif untuk meminimalisasi dan memulihkan lahan tercemar dengan melibatkan aktivitas mikroorganisme hingga persyaratan konsentrasi akhir limbah minyak bumi berupa Total Petroleum Hydrocarbons (TPH kurang dari 1%. Pemilihan mikroorganisme indigenous pada konsentrasi substrat kecil diharapkan menghasilkan nilai saturasi substrat terkecil sehingga tingkat afinitas tertinggi dapat diperoleh. Tujuan penelitian ini mencari dan mengidentifikasi isolat mikroorganisme petrofilik dari contoh uji hasil proses bioremediasi pada konsentrasi TPH 1%, menentukan nilai parameter kinetika biodegradasi, dan mengaplikasikan mikroorganisme terpilih pada proses bioremediasi tipe landfarming. Tahap isolasi dan identifikasi bakteri indigenous menghasilkan isolat bakteri Pseudomonas putida AK.A dan Pseudomonas diminuta AK.B. Penentuan kinetika biodegradasi dilakukan pada setiap jenis isolat dan kultur tercampur. Nilai laju pertumbuhan spesifik (µ, laju pertumbuhan spesifik maksimum (µmax, konsentrasi setengah jenuh (KS, koefisien produksi sintesis sel (Y, laju utilisasi substrat spesifik (q, laju utilisasi substrat spesifik maksimum (qmax, dan koefisien kematian indigenous (kd pada P. putida AK.A. berturut-turut sebesar 0,0679-0,0788/jam; 0,078/jam; 0,0152%; 0,1011; 0,6716-0,7794/jam; 0,76/jam; 0,0085/jam; P. diminuta AK.B sebesar 0,0754-0,0874/jam; 0,0873/jam; 0,0182%; 0,1246; 0,7458-0,8645/jam; 0,701/jam; 0,0058/jam; dan kultur tercampur sebesar 0,0825-0,0948/jam 0,0945/jam; 0,016%; 0,2257; 0,8160-0,9377/jam; 0,419/jam; 0,0035/jam. Kultur tercampur digunakan pada reaktor landfarming skala laboratorium. Berdasarkan hasil penelitian, isolat bakteri Pseudomonas dalam kultur tercampur dapat menurunkan konsentrasi TPH di

  19. Achieving second order advantage with multi-way partial least squares and residual bi-linearization with total synchronous fluorescence data of monohydroxy-polycyclic aromatic hydrocarbons in urine samples.

    Science.gov (United States)

    Calimag-Williams, Korina; Knobel, Gaston; Goicoechea, H C; Campiglia, A D

    2014-02-06

    An attractive approach to handle matrix interference in samples of unknown composition is to generate second- or higher-order data formats and process them with appropriate chemometric algorithms. Several strategies exist to generate high-order data in fluorescence spectroscopy, including wavelength time matrices, excitation-emission matrices and time-resolved excitation-emission matrices. This article tackles a different aspect of generating high-order fluorescence data as it focuses on total synchronous fluorescence spectroscopy. This approach refers to recording synchronous fluorescence spectra at various wavelength offsets. Analogous to the concept of an excitation-emission data format, total synchronous data arrays fit into the category of second-order data. The main difference between them is the non-bilinear behavior of synchronous fluorescence data. Synchronous spectral profiles change with the wavelength offset used for sample excitation. The work presented here reports the first application of total synchronous fluorescence spectroscopy to the analysis of monohydroxy-polycyclic aromatic hydrocarbons in urine samples of unknown composition. Matrix interference is appropriately handled by processing the data either with unfolded-partial least squares and multi-way partial least squares, both followed by residual bi-linearization.

  20. Implications of polluted soil biostimulation and bioaugmentation with spent mushroom substrate (Agaricus bisporus) on the microbial community and polycyclic aromatic hydrocarbons biodegradation.

    Science.gov (United States)

    García-Delgado, Carlos; D'Annibale, Alessandro; Pesciaroli, Lorena; Yunta, Felipe; Crognale, Silvia; Petruccioli, Maurizio; Eymar, Enrique

    2015-03-01

    Different applications of spent Agaricus bisporus substrate (SAS), a widespread agro-industrial waste, were investigated with respect to the remediation of a historically polluted soil with Polycyclic Aromatic Hydrocarbons (PAH). In one treatment, the waste was sterilized (SSAS) prior to its application in order to assess its ability to biostimulate, as an organic amendment, the resident soil microbiota and ensuing contaminant degradation. For the other treatments, two bioaugmentation approaches were investigated; the first involved the use of the waste itself and thus implied the application of A. bisporus and the inherent microbiota of the waste. In the second treatment, SAS was sterilized and inoculated again with the fungus to assess its ability to act as a fungal carrier. All these treatments were compared with natural attenuation in terms of their impact on soil heterotrophic and PAH-degrading bacteria, fungal growth, biodiversity of soil microbiota and ability to affect PAH bioavailability and ensuing degradation and detoxification. Results clearly showed that historically PAH contaminated soil was not amenable to natural attenuation. Conversely, the addition of sterilized spent A. bisporus substrate to the soil stimulated resident soil bacteria with ensuing high removals of 3-ring PAH. Both augmentation treatments were more effective in removing highly condensed PAH, some of which known to possess a significant carcinogenic activity. Regardless of the mode of application, the present results strongly support the adequacy of SAS for environmental remediation purposes and open the way to an attractive recycling option of this waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Significance of Microbiology in Porous Hydrocarbon Related Systems

    KAUST Repository

    Augsburger, Nicolas

    2017-07-01

    This thesis explores bio-mediated processes in geotechnical and petroleum engineering. Worldwide energy consumption is rapidly increasing as the world population and per-capita consumption rises. The US Energy Information Agency (EIA) predicts that hydrocarbons will remain the primary energy source to satisfy the surging energy demands in the near future. The three topics described in detail in this document aim to link microbiology with geotechnical engineering and the petroleum industry. Microorganisms have the potential to exploit residual hydrocarbons in depleted reservoirs in a technique known as microbial enhanced oil recovery, MEOR. The potential of biosurfactants was analyzed in detail with a literature review. Biosurfactant production is the most accepted MEOR technique, and has been successfully implemented in over 700 field cases. Temperature is the main limiting factor for these techniques. The dissolution of carbonates by microorganisms was investigated experimentally. We designed a simple, economical, and robust procedure to monitor diffusion through porous media. This technique determined the diffusion coefficient of H+ in 1.5% agar, 1.122 x 10-5 cm2 sec-1, by using bromothymol blue as a pH indicator and image processing. This robust technique allows for manipulation of the composition of the agar to identify the effect of specific compounds on diffusion. The Red Sea consists of multiple seeps; the nearby sediments are telltales of deeper hydrocarbon systems. Microbial communities associated with the sediments function as in-situ sensors that provide information about the presence of carbon sources, metabolites, and the remediation potential. Sediments seeps in the Red Sea revealed different levels of bioactivity. The more active seeps, from the southern site in the Red Sea, indicated larger pore sizes, higher levels of carbon, and bioactivity with both bacteria and archaeal species present.

  2. 以烃类为碳源的微生物驱油探索研究%STUDY ON MICROBIAL FLOODING WITH HYDROCARBON AS CARBON SOURCE

    Institute of Scientific and Technical Information of China (English)

    韩培慧; 石梅; 孙凤荣

    2001-01-01

    According to the physical and chemical environment, this paper separates and selects 8 stems of facultative anaerobic bacteria from hundreds of oil bearing sewage and performs a systematic performance evaluation and effect evaluation of the physical simulation experimental displacement efficiency with long tube filling oil sand. The experimental result shows that the selected stems of bacteria can grow with oil as the only carbon source in anaerobic condition and has the effect of degrading oil, reducing oil viscosity, producing active matter and decreasing interfacial tension. Core displacement experiment shows that microbial flooding can improve recovery by 10%.%针对大庆油田油层的物化环境,从数百个含油污水中分离、筛选了8株以烃类为碳源的兼性厌氧菌,并进行了系统的性能评价和长管填充油砂模型物理模拟实验驱油效果评价。实验结果表明,所筛选的8株菌种,在厌氧条件下,能以原油为唯一碳源生长、繁殖,并具有降解原油,降低原油粘度,产生活性物质,降低界面张力的作用。岩心驱替实验表明,微生物驱比水驱提高采收率10%左右。

  3. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  4. Residues of Oxytetracycline, Sulfamethoxazole, Sulfamethoxazole+Trimethoprim and Enrofloxacin after withdrawal time in white shrimp (Penaeus vannamei detected by Microbial Inhibition Disc Assay versus Screening Test Kit “SAM-Test”

    Directory of Open Access Journals (Sweden)

    Chalermchaikit, T.

    2005-02-01

    Full Text Available Medicated feed had been given to white shrimp (Penaeus vannamei for 7 days. Shrimp samples, collected at day-1 to day-7 after withdrawal time, were tested for antimicrobial residues by microbial inhibition disk assay (MIDA and “SAM-Test”. The results from “SAM-Test” indicated much higher numbers of positive (antimicrobial detectable samples than MIDA. Percentages of positive samples from oxytetracycline, sulfamethoxazole+trimethoprim and enrofloxacin treatment groups were decreased on day-3 or day-4after drug withdrawal but increased on day-5 or day-6. In one of shrimp samples from sulfamethoxazole treatment groups, residues could not be detected on day-4 to day-6 after drug withdrawal but they were detectable again on day-7. These phenomena might indicate that eating behavior of shrimp had retaken antimicrobial residues that were bound on their faeces. Therefore, it is impractical to determine the antibiotic withdrawal period in white shrimp by using withdrawal time of other aquatic animals. Further data of pharmacokinetics is critically important for determining the withdrawal time of antibiotic use in white shrimp farming.

  5. Sequential biodegradation of complex naphtha hydrocarbons under methanogenic conditions in two different oil sands tailings.

    Science.gov (United States)

    Mohamad Shahimin, Mohd Faidz; Siddique, Tariq

    2017-02-01

    Methane emissions in oil sands tailings ponds are sustained by anaerobic biodegradation of unrecovered hydrocarbons. Naphtha (primarily C6-C10; n- iso- and cycloalkanes) is commonly used as a solvent during bitumen extraction process and its residue escapes to tailings ponds during tailings deposition. To investigate biodegradability of hydrocarbons in naphtha, mature fine tailings (MFT) collected from Albian and CNRL tailings ponds were amended with CNRL naphtha at ∼0.2 wt% (∼2000 mg L(-1)) and incubated under methanogenic conditions for ∼1600 d. Microbial communities in both MFTs started metabolizing naphtha after a lag phase of ∼100 d. Complete biodegradation/biotransformation of all n-alkanes (except partial biodegradation of n-octane in CNRL MFT) followed by major iso-alkanes (2-methylpentane, 3-methylhexane, 2- and 4-methylheptane, iso-nonanes and 2-methylnonane) and a few cycloalkanes (derivatives of cyclopentane and cyclohexane) was observed during the incubation. 16S rRNA gene pyrosequencing showed dominance of Peptococcaceae and Anaerolineaceae in Albian MFT and Anaerolineaceae and Syntrophaceae in CNRL MFT bacterial communities with co-domination of Methanosaetaceae and "Candidatus Methanoregula" in archaeal populations during active biodegradation of hydrocarbons. The findings extend the known range of hydrocarbons susceptible to methanogenic biodegradation in petroleum-impacted anaerobic environments and help refine existing kinetic model to predict greenhouse gas emissions from tailings ponds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. 微生物修复土壤多环芳烃污染的研究进展%Microbial Remediation of Polycyclic Aromatic Hydrocarbons Contaminated Soil:A Review

    Institute of Scientific and Technical Information of China (English)

    侯梅芳; 潘栋宇; 黄赛花; 刘超男; 赵海青; 唐小燕

    2014-01-01

    多环芳烃是一类具有致癌、致畸、致突变性质的持久性有机污染物,主要来源于煤、石油等燃料的不完全燃烧,易吸附于固体颗粒表面和有机腐殖质,化学结构稳定,能长期存在于自然环境,给人类健康和生态环境带来很大的危害。中国土壤多环芳烃污染严重,因此急需寻求有效的修复方法进行治理。在众多的多环芳烃污染修复方法中,微生物修复因其低成本、高效、污染少等优点成为研究热点。科学家们从自然界中分离出了多种细菌、真菌等具有降解多环芳烃能力的微生物,并对多环芳烃的降解机理进行了探索,结果表明,微生物在代谢活动过程中能够产生酶来实现对土壤中多环芳烃的降解。细菌主要通过产生双加氧酶来催化多环芳烃的加氧反应,而真菌可以通过分泌木质素降解酶系或单加氧酶来氧化多环芳烃。两种途径均是首先通过降低多环芳烃的稳定性,使之容易被进一步降解。目前,微生物修复技术正逐步应用于PAHs污染土壤的实地修复,且已取得一定成效。文章简要介绍了降解多环芳烃的微生物,对多环芳烃的微生物降解机制进行了综述,讨论了影响微生物修复过程的因素,列举了常见的微生物修复相关技术,展望了今后的研究趋势。%Polycyclic aromatic hydrocarbons (PAHs), which mainly resulted from incomplete combustion of coal, petroleum and other fuels, are a kind of carcinogenic, teratogenic and mutagenic persistent organic pollutants (POPs). Each of them has stable chemical structure and easily adsorb on solid surface and organic humus. For this case, PAHs can exist in the natural environment for a long time and has great potential harm to human health and ecological environment. In China, the PAHs pollution in soil is a very serious problem, so it is urgent to explore an effective technology for removal of PAHs

  7. MICROORGANISMS’ SURFACE ACTIVE SUBSTANCES ROLE IN HYDROCARBONS BIODEGRADATION

    Directory of Open Access Journals (Sweden)

    Оlga Vasylchenko

    2012-09-01

    Full Text Available  Existing data and publications regarding oil, hydrocarbon biodegradation, metabolism, and bioremediation were analyzed. Search of hydrocarbon degrading bacteria which are producers of biosurfactants was provided, types of microbial surfactants and their physiological role were analyzed and ordered. The study of factors affecting the surface active properties of producers’ cultures was done.

  8. Petroleum hydrocarbon concentration in sediments along northern west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Kadam, A.N.

    Gas chromatography revealed that nonpolar material extracted from surface sediments collected along the northern west coast of India was originated from petroleum hydrocarbon residue. Petroleum hydrocarbon levels as determinEd. by fluorescence...

  9. Power from wastewater and residual products

    DEFF Research Database (Denmark)

    Krogh-Jeppesen, K.

    2007-01-01

    Microbial fuel cells utilise wastewater and residual products from the pretreatment of straw to generate power. Denmark could lead the way......Microbial fuel cells utilise wastewater and residual products from the pretreatment of straw to generate power. Denmark could lead the way...

  10. Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants in fish using fast, low-pressure gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sapozhnikova, Yelena, E-mail: yelena.sapozhnikova@ars.usda.gov [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States); Lehotay, Steven J. [US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 193038 (United States)

    2013-01-03

    Highlights: Black-Right-Pointing-Pointer A method for analysis of POPs and novel flame retardants in catfish was developed. Black-Right-Pointing-Pointer The method is based on a QuEChERS extraction, d-SPE clean-up and low pressure GC/MS-MS. Black-Right-Pointing-Pointer The method validation demonstrated good recoveries and low detection limits. Black-Right-Pointing-Pointer The method was successfully applied for analysis of catfish samples from the market. - Abstract: A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS-MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1 h/analyst, and LP-GC/MS-MS analysis provided fast separation of multiple analytes within 9 min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n = 5). The measured values for both SRMs agreed with certified/reference values (72-119% accuracy) for the majority of analytes. The detection limits were 0.1-0.5 ng g{sup -1} for PCBs, 0.5-10 ng g{sup -1} for PBDEs, 0.5-5 ng g{sup -1} for select pesticides and PAHs and 1-10 ng g{sup -1} for flame retardants. The developed method was successfully applied for analysis of catfish samples

  11. The Influence of Different Microbial Inoculants on the Fermentation Process of Chinese Herb Residues%不同菌剂对中药渣发酵过程的影响

    Institute of Scientific and Technical Information of China (English)

    王茂; 郭鑫; 韩峰; 曾莉; 刘然; 曾永清

    2015-01-01

    从发酵周期、pH值、臭气度、外观形状及总养分和有机质含量方面进行了试验与分析,试验表明:接种菌剂I的处理B腐熟效果最好,其经57d发酵,除含水量以外,所测指标均符合有机肥料的标准(NY525-2012)。发酵菌剂I对中药渣、鸡粪、菌渣的混合物料发酵周期最短,腐熟效果最好,可用于具有一定抑菌作用的酸性中药渣的资源化利用。%Through the analysis of fermentation period ,pH value ,odor intensity index ,appearance shape ,total nutrients and organic matter content ,the results of experiments show that treatment B of the microbial inoc‐ulants I has the best decomposition effect .After 57 days'fermentation ,the measurements of indexes are all conformed to the organic fertilizer's standard (NY525-2012) except the water content .The microbial inocu‐lants I has the shortest fermentation period for the mixed materials w hich consist of Chinese herb residues , chicken manure and fungi dregs and it has the best decomposition effect .Therefore ,the fermentation microbi‐al inoculants I can be used in resource utilization of acidic Chinese herb residues w hich have a certain bacteri‐ostatic action .

  12. Method of dispersing a hydrocarbon using bacteria

    Science.gov (United States)

    Tyndall, Richard L.

    1996-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  13. MECHANISMS OF MEMBRANE TOXICITY OF HYDROCARBONS

    NARCIS (Netherlands)

    Sikkema, Jan; Poolman, Bert; de Bont, J.A.M.

    1995-01-01

    Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this nl ea. The metaboli

  14. Mechanism of Silurian Hydrocarbon Pool Formation in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Liu Luofu; Guo Yongqiang; Zhao Yande; Li Yan; Chen Yuanzhuang; Chen Lixin; Pang Xiongqi; Xie Qilai; Huo Hong; Zhao Suping; Li Chao; Li Shuangwen

    2007-01-01

    There are three formation stages of Silurian hydrocarbon pools in the Tarim Basin. The widely distributed asphaltic sandstones in the Tazhong (central Tarim) and Tabei (northern Tarim) areas are the results of destruction of hydrocarbon pools formed in the first-stage, and the asphaltic sandstones around the Awati Sag were formed in the second-stage. The hydrocarbon migration characteristics reflected by the residual dry asphalts could represent the migration characteristics of hydrocarbons in the Silurian paleo-pools, while the present movable oil in the Silurian reservoirs is related to the later-stage (the third-stage) hydrocarbon accumulation.

  15. Microbial Life in a Liquid Asphalt Desert

    CERN Document Server

    Schulze-Makuch, Dirk; Antonio, Marina Resendes de Sousa; Ali, Denzil; Hosein, Riad; Song, Young C; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M; Guinan, Edward; Lehto, Harry J; Hallam, Steven J

    2010-01-01

    An active microbiota, reaching up to 10 E+7 cells/g, was found to inhabit a naturally occurring asphalt lake characterized by low water activity and elevated temperature. Geochemical and molecular taxonomic approaches revealed novel and deeply branching microbial assemblages mediating anaerobic hydrocarbon degradation, metal respiration and C1 utilization pathways. These results open a window into the origin and adaptive evolution of microbial life within recalcitrant hydrocarbon matrices, and establish the site as a useful analog for the liquid hydrocarbon environments on Saturn's moon Titan.

  16. Biodegradation of petroleum hydrocarbons in estuarine sediments: metal influence.

    Science.gov (United States)

    Almeida, Raquel; Mucha, Ana P; Teixeira, Catarina; Bordalo, Adriano A; Almeida, C Marisa R

    2013-02-01

    In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.

  17. 微生物法检测实验动物血清中的抗生素残留%Antibiotic residue monitoring in laboratory animal serum by microbial inhibition test

    Institute of Scientific and Technical Information of China (English)

    邢进; 冯育芳; 岳秉飞; 贺争鸣

    2013-01-01

    目的 建立实验动物血清中抗生素残留检测方法,保证微生物质量检测结果的准确.方法 采用微生物抑制法,用嗜热脂肪芽孢杆菌作为指示菌,对1640份实验动物血清进行抗生素残留检测.并与Premi@Test 抗生素检测试剂盒进行比对.结果 在受试样品中,检测出小鼠、大鼠、豚鼠、兔和犬的血清中存在抗生素残留,阳性率分别为27.2%、16.4%、39.9%、23.7%和47.6%.抽取82份血清和18份阴阳对照品,与Premi@Test检测的结果相比较差异不显著(X2=16.680,P>0.05).血清中抗生素的残留与DHL琼脂平皿的菌落生长有一定相关性(X2=9.939,P<0.05).结论 本研究采用嗜热脂肪芽孢杆菌作为指示菌的微生物抑制法,能够对动物血清中的抗生素进行检测,具有良好的敏感性和重复性,成本低,操作简便.为实验动物体内抗生素残留检测和微生物学检测结果的准确性提供依据.%Objective To develop a detection method for antibiotic residues in laboratory animal serum, and to ensure the accuracy of the results of the microbiological quality monitoring. Methods Antibiotic residues in 1640 serum samples of laboratory animals were tested by microbial inhibition assay of Bacillus stearothermophilus, and the results were compared with that of the antibiotic detection kit Premi@ Test. Results Antibiotic residues were positive in sera of mice, rats, guinea pigs, rabbits and dogs, with a positive rate of 27. 2% , 16. 4% , 39. 9% , 23. 7% and 47. 6% , respectively. The results were consistent with that obtained with Premi test( X = 16. 680, P > 0. 05). Serum antibiotic residues and DHL agar colony growth had certain correlation (X2 = 9. 939, P < 0. 05 ) . Conclusions The microbial inhibition method of Bacillus stearothermophilus used as an indicator is not only capable of detecting antibiotic residues in animal sera, low cost, and simple operation, but also has a good sensitivity and repeatability. This

  18. Mineralisation of target hydrocarbons in three contaminated soils from former refinery facilities

    Energy Technology Data Exchange (ETDEWEB)

    Towell, Marcie G. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Bellarby, Jessica; Paton, Graeme I. [Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Coulon, Frederic; Pollard, Simon J.T. [School of Applied Sciences, Sustainable Systems Department, Cranfield University, Cranfield (United Kingdom); Semple, Kirk T., E-mail: k.semple@lancaster.ac.u [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2011-02-15

    This study investigated the microbial degradation of {sup 14}C-labelled hexadecane, octacosane, phenanthrene and pyrene and considered how degradation might be optimised in three genuinely hydrocarbon-contaminated soils from former petroleum refinery sites. Hydrocarbon mineralisation by the indigenous microbial community was monitored over 23 d. Hydrocarbon mineralisation enhancement by nutrient amendment (biostimulation), hydrocarbon degrader addition (bioaugmentation) and combined nutrient and degrader amendment, was also explored. The ability of indigenous soil microflora to mineralise {sup 14}C-target hydrocarbons was appreciable; {>=}16% mineralised in all soils. Generally, addition of nutrients or degraders increased the rates and extents of mineralisation of {sup 14}C-hydrocarbons. However, the addition of nutrients and degraders in combination had a negative effect upon {sup 14}C-octacosane mineralisation and resulted in lower extents of mineralisation in the three soils. In general, the rates and extents of mineralisation will be dependent upon treatment type, nature of the contamination and adaptation of the ingenious microbial community. - Research highlights: Indigenous microbes actively degrade {sup 14}C-hydrocarbons in field contaminated soils. Addition of nutrients or degraders enhance mineralisation in contaminated soils. Biodegradation is related to the presence of hydrocarbons and microbial activity. - Bioremediation strategy, native hydrocarbon concentrations and prior exposure histories of the microbial community influence hydrocarbon degradation in soil.

  19. Impact of Reed Canary Grass Cultivation and Mineral Fertilisation on the Microbial Abundance and Genetic Potential for Methane Production in Residual Peat of an Abandoned Peat Extraction Area

    Science.gov (United States)

    Espenberg, Mikk; Truu, Marika; Truu, Jaak; Maddison, Martin; Nõlvak, Hiie; Järveoja, Järvi; Mander, Ülo

    2016-01-01

    This study examined physiochemical conditions and prokaryotic community structure (the bacterial and archaeal 16S rRNA genes and mcrA gene abundances and proportions), and evaluated the effect of reed canary grass cultivation and mineral fertilisation on these factors, in the 60 cm thick residual peat layer of experimental plots located on an abandoned peat extraction area. The archaeal proportion was 0.67–39.56% in the prokaryotic community and the methanogens proportion was 0.01–1.77% in the archaeal community. When bacterial abundance was higher in the top 20 cm of peat, the archaea were more abundant in the 20–60 cm layer and methanogens in the 40–60 cm layer of the residual peat. The bacterial abundance was significantly increased, but archaeal abundance was not affected by cultivation. The fertiliser application had a slight effect on peat properties and on archaeal and methanogen abundances in the deeper layer of cultivated peat. The CH4 emission was positively related to mcrA abundance in the 20–60 cm of the bare peat, while in case of reed canary grass cultivation these two parameters were not correlated. Reed canary grass cultivation mitigated CH4 emission, although methanogen abundance remained approximately the same or even increased in different layers of residual peat under cultivated sites over time. This study supports the outlook of using abandoned peat extraction areas to produce reed canary grass for energy purposes as an advisable land-use practice from the perspective of atmospheric impact in peatland-rich Northern Europe. PMID:27684377

  20. The hydrocarbon sphere

    Energy Technology Data Exchange (ETDEWEB)

    Mandev, P.

    1984-01-01

    The hydrocarbon sphere is understood to be the area in which hydrocarbon compounds are available. It is believed that the lower boundary on the hydrocarbon sphere is most probably located at a depth where the predominant temperatures aid in the destruction of hydrocarbons (300 to 400 degrees centigrade). The upper limit on the hydrocarbon sphere obviously occurs at the earth's surface, where hydrocarbons oxidize to H20 and CO2. Within these ranges, the occurrence of the hydrocarbon sphere may vary from the first few hundred meters to 15 kilometers or more. The hydrocarbon sphere is divided into the external (mantle) sphere in which the primary gas, oil and solid hydrocarbon fields are located, and the internal (metamorphic) sphere containing primarily noncommercial accumulations of hydrocarbon gases and solid carbon containing compounds (anthraxilite, shungite, graphite, etc.) based on the nature and scale of hydrocarbon compound concentrations (natural gas, oil, maltha, asphalt, asphaltite, etc.).

  1. Evaluation of aerobic co-composting of penicillin fermentation fungi residue with pig manure on penicillin degradation, microbial population dynamics and composting maturity.

    Science.gov (United States)

    Zhang, Zhenhua; Zhao, Juan; Yu, Cigang; Dong, Shanshan; Zhang, Dini; Yu, Ran; Wang, Changyong; Liu, Yan

    2015-12-01

    Improper treatment of penicillin fermentation fungi residue (PFFR), one of the by-products of penicillin production process, may result in environmental pollution due to the high concentration of penicillin. Aerobic co-composting of PFFR with pig manure was determined to degrade penicillin in PFFR. Results showed that co-composting of PFFR with pig manure can significantly reduce the concentration of penicillin in PFFR, make the PFFR-compost safer as organic fertilizer for soil application. More than 99% of penicillin in PFFR were removed after 7-day composting. PFFR did not affect the composting process and even promote the activity of the microorganisms in the compost. Quantitative PCR (qPCR) indicated that the bacteria and actinomycetes number in the AC samples were 40-80% higher than that in the pig-manure compost (CK) samples in the same composting phases. This research indicated that the aerobic co-composting was a feasible PFFR treatment method.

  2. Decomposition rates and residue-colonizing microbial communities of Bacillus thuringiensis insecticidal protein Cry3Bb-expressing (Bt) and non-Bt corn hybrids in the field.

    Science.gov (United States)

    Xue, Kai; Serohijos, Raquel C; Devare, Medha; Thies, Janice E

    2011-02-01

    Despite the rapid adoption of crops expressing the insecticidal Cry protein(s) from Bacillus thuringiensis (Bt), public concern continues to mount over the potential environmental impacts. Reduced residue decomposition rates and increased tissue lignin concentrations reported for some Bt corn hybrids have been highlighted recently as they may influence soil carbon dynamics. We assessed the effects of MON863 Bt corn, producing the Cry3Bb protein against the corn rootworm complex, on these aspects and associated decomposer communities by terminal restriction fragment length polymorphism (T-RFLP) analysis. Litterbags containing cobs, roots, or stalks plus leaves from Bt and unmodified corn with (non-Bt+I) or without (non-Bt) insecticide applied were placed on the soil surface and at a 10-cm depth in field plots planted with these crop treatments. The litterbags were recovered and analyzed after 3.5, 15.5, and 25 months. No significant effect of treatment (Bt, non-Bt, and non-Bt+I) was observed on initial tissue lignin concentrations, litter decomposition rate, or bacterial decomposer communities. The effect of treatment on fungal decomposer communities was minor, with only 1 of 16 comparisons yielding separation by treatment. Environmental factors (litterbag recovery year, litterbag placement, and plot history) led to significant differences for most measured variables. Combined, these results indicate that the differences detected were driven primarily by environmental factors rather than by any differences between the corn hybrids or the use of tefluthrin. We conclude that the Cry3Bb corn tested in this study is unlikely to affect carbon residence time or turnover in soils receiving these crop residues.

  3. An evaluation method of hydrocarbon generating potential of highly mature and over-mature marine carbonate

    Institute of Scientific and Technical Information of China (English)

    程克明; 王兆云

    1997-01-01

    How to restore the residual organic carbon and residual hydrocarbon-generating potential is discussed based on the hydrocarbon degradability of source rock. The results indicate there is linear function relationship between the restoring coefficient of residual organic carbon (Kc) and the vitrinite reflectance (Ro% ) of various kinds of source rock, but the relationship is secondary functional between the restoring coefficient of residual hydrocarbon-generating potential (Ks) and the vitrinite reflectance (R0%). It is pointed out that Kc= (1 - Dresidual)/(1-Dprimary), Xs=Kc (Dprimary/Dresidual). The restoration of residual organic carbon and hydrocarbon-gen era ting potential of the Cambrian and Ordovician highly mature marine carbonate in the Tarim Basin and North China region shows that the lower limit value of hydrocarbon generating potential and the organic matter abundance of carbonate source rock are basically the same as that of clastic rock. The technical difficulty in hydrocarbon generating eva

  4. Effects of controlled-release fertilizer coating residual on soil microbial quantity and enzyme activity%控释肥残膜对小麦各生育期土壤微生物和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    刘明; 张民; 杨越超; 程冬冬

    2011-01-01

    为了探明控释肥树脂残膜对土壤环境可能造成的影响,采用小麦池栽试验研究了控释肥树脂残膜对土壤有关微生物数量和酶活性的影响。结果表明,控释肥树脂残膜使土壤细菌和放线菌数量分别相对增加了19.01%~62.87%和17.03%~132.39%,土壤脲酶、转化酶、中性磷酸酶活性分别提高了17.39%~85.71%、31.77%~158.40%、35.14%~189.47%,但对过氧化氢酶活性无明显影响。施肥处理(施肥不施残膜和施肥施残膜处理)显著增加了土壤转化酶和中性磷酸酶活性;但对土壤细菌和放线菌数量、过氧化氢%Effects of controlled-release fertilizer(CRF) resin coating residual on microbial quantity and enzyme activity in soil were investigated in winter wheat experiment.The results indicated that with application of CRF resin coating residual,the numbers of bacteria and actinomyces were increased by 19.01%-62.87% and 17.03%-132.39%,respectively.The activities of soil urease,invertase,neutral phosphatase were significantly increased by 17.39%-85.71%,31.77%-158.40%,35.14%-189.47%,respectively,while the soil catalase activity was not affected.The activities of invertase,neutral phosphatase were improved by applying fertilizer to the soil(fertilizer with and without CRF resin coating residual treatments),however,the amounts of bacteria and actinomyces and the activities of catalase,urease were not changed.The amounts of bacteria and actinomyces and the activities of some enzymes could not be restrained under the condition of applying CRF resin coating residual at the range of 90~360 g/m2 in soil.

  5. BIODEGRADATION OF HYDROCARBON VAPORS IN THE UNSATURATED ZONE

    Science.gov (United States)

    The time-averaged concentration of hydrocarbon and oxygen vapors were measured in the unsaturated zone above the residually contaminated capillary fringe at the U.S. Coast Guard Air Station in Traverse City, Michigan. Total hydrocarbon and oxygen vapor concentrations were observe...

  6. Água residuária de esgoto doméstico tratado na atividade microbiana do solo e crescimento da mamoneira Treated wastewater from domestic sewage on soil microbial activity and growth of castor bean

    Directory of Open Access Journals (Sweden)

    Karine da S. Simões

    2013-05-01

    Full Text Available Os resíduos de esgoto doméstico apresentam teores de macro e micro nutrientes suficientes para atender a uma grande parte das culturas. Além de ser uma alternativa viável para aumentar a disponibilidade hídrica é uma forma efetiva de controle de poluição e preservação do meio ambiente. Neste contexto, realizou-se um experimento para avaliar a influência da aplicação de diferentes diluições de água residuária proveniente de esgoto doméstico tratado, na atividade microbiana de um Latossolo Amarelo Distrocoeso do Recôncavo Baiano e no crescimento inicial de plantas de mamoneira anã MPB 01. Avaliaram-se a atividade microbiana do solo e as características de crescimento da planta: altura, diâmetro do colo, biomassa seca da parte aérea, biomassa seca da raiz e volume de raízes. De acordo com os resultados, o efluente de esgoto doméstico tratado sem diluição estimula a atividade microbiana do Latossolo Amarelo Distrocoeso e prejudica o crescimento inicial da mamoneira anã MPB 01.Wastewater from domestic sewage presents levels of macro and micro nutrients sufficient to support a large part of the crops. Besides being a viable alternative to increase water availability, it is an effective way to control pollution and preserve the environment. In this context, an experiment was carried out to evaluate the influence of applying different dilutions of treated wastewater from domestic sewage on the microbial activity of a distrophic cohesive yellow Latosol in the Recôncavo of Bahia. Its effect on early growth of dwarf castor bean plants MPB 01 were also evaluated. Soil microbial activity and growth characteristics such as plant height, stem diameter, shoot dry weight, root dry weight and root volume were evaluated. According to the results, the effluent of treated wastewater without dilution, stimulates microbial activity of distrophic cohesive yellow Latosol and impairs the early growth of dwarf castor bean MPB 01.

  7. Petroleum hydrocarbon concentration in surface sediments in continental shelf region along the central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Kadam, A.N.

    Gas chromatography revealed that nonpolar material extracted from surface sediments collected along the northern west coast of India was originated from petroleum hydrocarbon residue. Petroleum hydrocarbon levels as determinEd. by fluorescence...

  8. Microbial community analysis of a coastal salt marsh affected by the Deepwater Horizon oil spill.

    Directory of Open Access Journals (Sweden)

    Melanie J Beazley

    Full Text Available Coastal salt marshes are highly sensitive wetland ecosystems that can sustain long-term impacts from anthropogenic events such as oil spills. In this study, we examined the microbial communities of a Gulf of Mexico coastal salt marsh during and after the influx of petroleum hydrocarbons following the Deepwater Horizon oil spill. Total hydrocarbon concentrations in salt marsh sediments were highest in June and July 2010 and decreased in September 2010. Coupled PhyloChip and GeoChip microarray analyses demonstrated that the microbial community structure and function of the extant salt marsh hydrocarbon-degrading microbial populations changed significantly during the study. The relative richness and abundance of phyla containing previously described hydrocarbon-degrading bacteria (Proteobacteria, Bacteroidetes, and Actinobacteria increased in hydrocarbon-contaminated sediments and then decreased once hydrocarbons were below detection. Firmicutes, however, continued to increase in relative richness and abundance after hydrocarbon concentrations were below detection. Functional genes involved in hydrocarbon degradation were enriched in hydrocarbon-contaminated sediments then declined significantly (p<0.05 once hydrocarbon concentrations decreased. A greater decrease in hydrocarbon concentrations among marsh grass sediments compared to inlet sediments (lacking marsh grass suggests that the marsh rhizosphere microbial communities could also be contributing to hydrocarbon degradation. The results of this study provide a comprehensive view of microbial community structural and functional dynamics within perturbed salt marsh ecosystems.

  9. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Nai; TIAN ZuoJi; LENG YingYing; WANG HuiTong; SONG FuQing; MENG JianHua

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2)branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4)phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hydrocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclusions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydrocarbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram.And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion,saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  10. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2) branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4) phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hy-drocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclu-sions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydro-carbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram. And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion, saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  11. Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

    Science.gov (United States)

    Boyle, M A; O'Donnell, M J; Russell, R J; Galvin, N; Swan, J; Coleman, D C

    2015-10-01

    Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (Psuction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces cannot be adequately

  12. Atividade microbiana em solos, influenciada por resíduos de algodão e torta de mamona Microbial activity in soils influenced by residues of cotton and castor bean presscake

    Directory of Open Access Journals (Sweden)

    Silvia Capuani

    2012-12-01

    Full Text Available A atividade microbiana não se constitui apenas como bom indicador da qualidade do solo, mas é influenciada pela adição de carbono no sistema, o qual serve como substrato aos micro-organismos que aumentam sua atividade e a liberação de CO2, compreendendo a respiração edáfica do solo. Objetivou-se, neste trabalho, avaliar a atividade microbiana em diferentes tipos de solo com a adição de torta de mamona e resíduo têxtil de algodão. O trabalho foi conduzido em casa de vegetação na sede da Embrapa Algodão, em delineamento de blocos casualisados em esquema fatorial 4 x 3, com quatro repetições. A intervalos predeterminados de 4 dias os recipientes foram abertos e a solução de NaOH foi titulada com HCl 2 N na presença de indicador ácido/base fenolftaleína. Após a leitura a mesma quantidade de NaOH foi reposta e os recipientes novamente fechados. A diferença entre a quantidade de ácido necessária para neutralizar o hidróxido de sódio no recipiente testemunha e nos tratamentos equivale à quantidade de gás carbônico produzido pelos micro-organismos do solo. Constatou-se que os resíduos influenciaram significativamente a atividade microbiana nos diferentes tipos de solo, sobretudo nas primeiras determinações, apresentando-se como boas fontes para mineralização e fornecimento de nutrientes, tendo a torta de mamona proporcionado maior liberação acumulada de CO2 pelos micro-organismos.Microbial activity constitutes a good indicator of soil quality, and is influenced by the addition of carbon in the system serving as a substrate for microorganisms that increase their activity and release of CO2, comprising the edaphic respiration of the soil. The objective of this study was to evaluate the microbial activity in different soil types with the addition of cake press of castor bean and cotton textile residue. The study was conducted in a greenhouse at the headquarters of Embrapa Cotton in randomized block design in 4 x 3

  13. Performance and microbial diversity of bio-PRB reactor in the remediation of groundwater contaminated by petroleum hydrocarbons%生物可渗透性反应墙修复石油烃污染地下水的效果及微生物多样性研究

    Institute of Scientific and Technical Information of China (English)

    刘虹; 张兰英; 刘娜; 高松; 李志萍

    2013-01-01

    采用可渗透性反应墙(PRB)协同微生物作用对石油烃污染地下水进行室内模拟修复.研究结果表明,生物PRB对石油烃污染地下水具有较好的处理效果.反应器运行200 d后,生物PRB前端介质总石油烃(TPH)含量高,15个取样点的TPH质量浓度为0.74~5.42 mg/L,后端介质TPH含量较低且分布较均匀,10个取样点中TPH均低于0.29 mg/L,生物PRB出水中未检出TPH.采用聚合酶链式反应(PCR)-变性梯度凝胶电泳(DGGE)技术对生物PRB内的微生物群落结构进行分析,结果显示,生物PRB中微生物群落结构的相似性随着横向距离的增大而降低,其中B2与B5取样点微生物相似度最高,达83.1%.在生物PRB前端TPH浓度高的部位,微生物群落较为稳定,多样性较低,而后端TPH浓度低的部位,微生物群落不稳定,多样性较高.%The permeable reactive barrier (PRB) combined with microbial action was designed for the bio-remediation of groundwater contaminated by petroleum hydrocarbons. The results indicated that the bio-PRB presented perfect performance for petroleum hydrocarbons removal. After 200 days of bioremediation,the total petroleum hydrocarbons (TPH) was higher in the fore-end of the reactor with the concentration ranged from 0. 74-5. 42 mg/L in the fore-end 15 sampling points, while it distributed averagely in the back-end of reactor with the TPH concentration of sampling points all lower than 0. 29 mg/L. There was no TPH detected in the effluent of the reactor after remediation. The PCR-DGGE technology was used to analyze the microbial community structure of bio-PRB, atlas of DGGE showed that the similarity of microbial community decreased along the length of bio-PRB,and the highest similarity of 83. 1% was found between B2 and B5. The microbial diversity was lower in fore-end of bio-PRB,microbial community was more stable in this area. Conversely,the microbial community was less stable and more diversiform in t back-end of reactor.

  14. Abnormal pressure in hydrocarbon environments

    Science.gov (United States)

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  15. Hydrocarbon degradation by Antarctic coastal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.E. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre; CSIRO Div of Marine Research, Hobart (Australia); University of Tasmania, Hobart (Australia). Dept. of Agricultural Science; Nichols, P.D. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre; CSIRO Div. of Marine Research, Hobart (Australia); Franzmann, P.D. [CSIRO Land and Water, Wembley (Australia); McMeekin, T.A. [University of Tasmania, Hobart (Australia). Antarctic Cooperative Research Centre

    1999-07-01

    Bacterial cultures obtained through selective enrichment of beach sand collected 60 days and one year after treatment of sites in a pilot oil spill trial conducted at Airport Beach, Vestfold Hills, East Antarctica, were examined for the ability to degrade n-alkanes and phenanthrene. The effects of different hydrocarbon mixtures (Special Antarctic Blend [SAB] and BP-Visco), (fish oil [orange roughy]) and inoculation of replicate sites with water from Organic Lake, (previously shown to contain hydrocarbon-degrading bacteria) on the indigenous microbial population, were examined. Of the cultures obtained, those from sites treated with SAB and BP-Visco degraded n-alkanes most consistently and typically to the greatest extent. Two mixed cultures obtained from samples collected at 60 days and two isolates obtained from these cultures extensively degraded phenanthrene. 1-Hydroxy-naphthoic acid formed the major phenanthrene metabolite. Lower levels of salicyclic acid, 1-naphthol, 1,4-naphthaquinone and phenanthrene 9-10 dihydrodiol were detected in extracts of phenanthrene grown cultures. This study shows that under laboratory conditions indigenous Antarctica bacteria can degrade n-alkanes and the more recalcitrant polycyclic aromatic hydrocarbon, phenanthrene. The enrichment of hydrocarbon degrading microorganisms in Antarctic ecosystems exposed to hydrocarbons, is relevant for the long term fate of hydrocarbon spills in this environment. (author)

  16. N cycling and the composition of terpenes and tannins in boreal forest soils: Effects of logging residues

    Science.gov (United States)

    Smolander, Aino; Kitunen, Veikko; Kukkola, Mikko; Tamminen, Pekka

    2014-05-01

    There is increasing evidence available that certain terpenes and tannins may mediate substantial changes in nitrogen cycling processes in boreal forest soils. Terpenes and tannins are two important groups of plant secondary metabolites: Terpenes are hydrocarbons having different number of isoprene-derived units and tannins are complex polyphenolic compounds able to interact with proteins. Logging residues, consisting of fresh tree tops and branches with needles contain large amounts of terpenes and tannins. Currently there is increasing demand for forest biomass for bioenergy production. Therefore, harvesting of logging residues has become more common from both clear-cutting and thinning stands, instead of conventional stem-only harvest where logging residues are retained on the site. Our aim was to determine how logging residues affect soil N cycling processes in Scots pine and Norway spruce thinning stands in long-term, and how these processes are related to the composition of terpenes and tannins in the soil. Samples were taken from the humus layer of pine and spruce experiments which had been thinned 4-to-19 years before; in the thinning different amounts of logging residues had been distributed on the plots. Logging residues had only little effect on soil microbial biomass N or C. However, in several sites logging residues increased the rate of net N mineralization and the ratios net N mineralization/ C mineralization and net N mineralization/microbial biomass N, and these positive effects were very long-lasting. Logging residues also changed the composition of different terpenes and condensed tannins in soil. In general, with regard to the processes and ratios indicating N availability, stem-only harvest seems to be more favorable than whole-tree harvest. The results from long-term field experiments will be discussed in relation to the effects of different terpenes and tannins, observed in short-term laboratory experiments, on N cycling processes.

  17. Constraining Microbial Community Response During Oil Sands Reclamation via Lipid and Isotope Biosignatures

    Science.gov (United States)

    Bradford, L. M.; Ziolkowski, L. A.; Ngonadi, N.; Warren, L. A.; Slater, G. F.

    2013-12-01

    A pilot scale reclamation project in the Athabasca oil sands region (Fort McMurray, Alberta, Canada) has created an artificial freshwater fen typical of the boreal forest region in which the oil sands occur. At this site, composite tailings (CT) residue was overlain with a thick sand cap and a freshwater fen constructed on top. This project began in 2009, with most wetland development occurring over the summer of 2012. It is recognized that the response of microbial communities to reclamation activities has the potential to play a significant role in the outcome of reclamation. Microbial biodegradation of petroleum residues may improve reclamation outcomes, while production of by-products, particularly hydrogen sulphide gas (H2S) via bacterial sulphate reduction, must be assessed to manage any potential negative impacts. Phospholipid fatty acid (PLFA) concentration and isotopic analysis were used to characterize the response of in situ microbial communities within the reclamation fen system. Increases in PLFA concentrations were observed in sediment taken from the sand layer at sample sites within the fen from during its establishment. Initial values equivalent to circa 106 cells/gram in July 2011 increased to values equivalent to 107cells/gram in August 2012 and then to 108 cells/gram in November 2012. Analysis of the radiocarbon (Δ14C) content of total organic carbon shows an increase in Δ14C from highly depleted values (-983×2‰) in July 2011, consistent with petroleum hydrocarbons dominating the total organic carbon, to more 14C enriched values as fen development progressed (-423×2.1‰ in August 2012 and -417×1.4‰ in November 2012). This indicates inputs of more modern organic matter potentially associated with the peat used to construct the fen and/or inputs from recent photosynthesis. The correlation between the observed PLFA increases and this increase in modern carbon inputs suggests that reclamation activities have stimulated the increase in the

  18. Volatile hydrocarbons and fuel oxygenates: Chapter 12

    Science.gov (United States)

    Cozzarelli, Isabelle M.

    2014-01-01

    Petroleum hydrocarbons and fuel oxygenates are among the most commonly occurring and widely distributed contaminants in the environment. This chapter presents a summary of the sources, transport, fate, and remediation of volatile fuel hydrocarbons and fuel additives in the environment. Much research has focused on the transport and transformation processes of petroleum hydrocarbons and fuel oxygenates, such as benzene, toluene, ethylbenzene, and xylenes and methyl tert‐butyl ether, in groundwater following release from underground storage tanks. Natural attenuation from biodegradation limits the movement of these contaminants and has received considerable attention as an environmental restoration option. This chapter summarizes approaches to environmental restoration, including those that rely on natural attenuation, and also engineered or enhanced remediation. Researchers are increasingly combining several microbial and molecular-based methods to give a complete picture of biodegradation potential and occurrence at contaminated field sites. New insights into the fate of petroleum hydrocarbons and fuel additives have been gained by recent advances in analytical tools and approaches, including stable isotope fractionation, analysis of metabolic intermediates, and direct microbial evidence. However, development of long-term detailed monitoring programs is required to further develop conceptual models of natural attenuation and increase our understanding of the behavior of contaminant mixtures in the subsurface.

  19. Foaming of mixtures of pure hydrocarbons

    Science.gov (United States)

    Robinson, J. V.; Woods, W. W.

    1950-01-01

    Mixtures of pure liquid hydrocarbons are capable of foaming. Nine hydrocarbons were mixed in pairs, in all possible combinations, and four proportions of each combination. These mixtures were sealed in glass tubes, and the foaming was tested by shaking. Mixtures of aliphatic with other aliphatic hydrocarbons, or of alkyl benzenes with other alkyl benzenes, did not foam. Mixtures of aliphatic hydrocarbons with alkyl benzenes did foam. The proportions of the mixtures greatly affected the foaming, the maximum foaming of 12 of 20 pairs being at the composition 20 percent aliphatic hydrocarbon, 80 percent alkyl benzene. Six seconds was the maximum foam lifetime of any of these mixtures. Aeroshell 120 lubricating oil was fractionated into 52 fractions and a residue by extraction with acetone in a fractionating extractor. The index of refraction, foam lifetime, color, and viscosity of these fractions were measured. Low viscosity and high index fractions were extracted first. The viscosity of the fractions extracted rose and the index decreased as fractionation proceeded. Foam lifetimes and color were lowest in the middle fractions. Significance is attached to the observation that none of the foam lifetimes of the fractions or residue is as high as the foam lifetime of the original Aeroshell, indicating that the foaming is not due to a particular foaming constituent, but rather to the entire mixture.

  20. Relationship of Porous Evolution and Residual Hydrocarbon:Evidence from Modeling Experiment with Geological Constrains%页岩孔隙演化及其与残留烃量的关系:来自地质过程约束下模拟实验的证据

    Institute of Scientific and Technical Information of China (English)

    崔景伟; 朱如凯; 崔京钢

    2013-01-01

    Enhancing study of porous evolution of shale is of great significance for petroleum exploration in shale,especially for assessing the relationship of porous evolution and residual hydrocarbon quantitatively.Preventive lacustrine source rocks of type I with low maturity in Ordos Basin were collected and selected for modeling experiment of physical diagenesis in shale,combing with geological constrains of burial history,formation pressure and formation water salinity.Utilizing methods of mercury intrusion,nitrogen adsorption,CO2 adsorption we acquire specific pore volume,specific surface area and pore size distribution of shale in different temperature and pressure.In combination of ultrasonic extraction of bitumen "A" in trichloromethane,we try to figure out the relationship of porous evolution and residual hydrocarbon.Ultimately,we seek to interpret porous alteration by integrating analysis of TOC,XRD in whole rock and XRD in clay minerals.Results show that specific pore volume of macropores increase and then decrease with residual hydrocarbon,while in micropores and mesopores,specific pore volume decrease first and then increase with the rises of modeling temperature.XRD analysis presents that mineral contents are the controlling factor of macropores,and TOC and contents of clay minerals control micropores and mesopores.Enlargement of specific pore volume in micropores and mesopores implies remarkable reservoir space for shale gas generated in high-over maturity stage of kerogen pyrolysis and oil cracking.Specific pore volume of macropores varies consistently with residual hydrocarbon.Increase of macropores in oil window response to the favorable entrapment zones of shale oil.%加强页岩孔隙演化规律研究,特别是定量评价其与残留烃之间的关系对页岩油的勘探具有重要意义.采集鄂尔多斯盆地低成熟度湖相Ⅰ型富有机质页岩,通过地质条件约束(埋藏史、地层压力、地层水矿化度等)成岩物理模拟实

  1. Microbial turnover and incorporation of organic compounds in oil sand mining reclamation sites

    Science.gov (United States)

    Lappé, M.; Kallmeyer, J.

    2013-12-01

    Microorganisms play an important role in the development of new soils and in the reclamation of disturbed landscapes. Especially in hydrocarbon-contaminated soils their ability to degrade organic matter and pollutants makes them essential to re-establish full ecosystem functionality. Microbes are also involved in the mobilization of nutrients for plant growth and in the production of greenhouse gases. Reclamation sites from oil sand mining activities in Alberta, Canada, contain residual bitumen as well as other hydrocarbons. So, these areas provide a great opportunity to study microbial degradation of residual contaminants from oil sand. To get an impression of degradation rates as well as metabolic pathways, incubation experiments were performed in the lab. We measured microbial turnover (catabolic metabolism) and incorporation (anabolic metabolism) rates of different common organic compounds in samples from differently treated reclamation sites - with plant cover and without plant cover. About 10 g of sample material was suspended in 10 mL of a solution that mimics the in-situ concentration of dissolved ions. Radioactively labelled 14C-acetate was added as a common substrate, whereas 14C-naphthenic acid was chosen to investigate the microbial community's capability to utilize a typical hydrocarbon pollutant in oil sand tailings as a nutrient source. To test for the influence of fertilizers on microbial activity, phosphate, nitrate and potassium were added to some samples in different combinations. Incubations were run over two different time periods (7 and 14 days). At the end of each incubation experiment, the amount of produced 14CO2, 14C incorporated into the cells and the remaining unreacted 14C in the slurry were measured. First results show that most of the added 14C-acetate is used for respiration as it is mostly released as 14CO2. In upper soil layers only about 3% of 14C is incorporated into cells, whereas in deeper horizons with lower cell abundances

  2. Novel Photocatalytic Reactor Development for Removal of Hydrocarbons from Water

    Directory of Open Access Journals (Sweden)

    Morgan Adams

    2008-01-01

    Full Text Available Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the removal of hydrocarbons from two waste effluent sources. Two reactor concepts were considered: a simple flat plate immobilised film unit, and a new rotating drum photocatalytic reactor. Both units proved to be effective in removing residual hydrocarbons from the effluent with the drum reactor reducing the hydrocarbon content by 90% under 10 minutes.

  3. Bioremediation of petroleum hydrocarbons in anoxic marine sediments: consequences on the speciation of heavy metals.

    Science.gov (United States)

    Dell'Anno, Antonio; Beolchini, Francesca; Gabellini, Massimo; Rocchetti, Laura; Pusceddu, Antonio; Danovaro, Roberto

    2009-12-01

    We investigated the effects of biostimulation and bioagumentation strategies applied to harbor sediments displaying reducing conditions and high concentrations of petroleum hydrocarbons and heavy metals. We compared the microbial efficiency of hydrocarbon removal from sediments maintained for 60 days in anoxic conditions and inoculated with acetate, sulfate-reducing bacterial strains and acetate and sulfate-reducing bacteria. All treatments determined a significant increase in the microbial growth and significant decreases of hydrocarbon contents and of redox potential values. The addition of sulfate-reducing bacterial strains to the sediment was the most efficient treatment for the hydrocarbon removal. In all experiments, significant changes of the heavy metals' phase repartition were observed. The results reported here suggest that the biodegradation of petroleum hydrocarbons in anoxic marine sediments may be enhanced by stimulating microbial anaerobic metabolism, but care should be applied to monitor the potential changes in the mobility and bioavailability of heavy metals induced by bio-treatments.

  4. A Metagenomic Analysis of Microbial Contamination in Aviation Fuels

    Science.gov (United States)

    2009-03-01

    microbial growth at phase interfaces (liquid-liquid, liquid-solid, liquid-gas, and so forth) (ASTM, 1999). Biosurfactant , n. — A surface-active...toxic and biodegradable. Biosurfactants enhance the emulsification of hydrocarbons, have the potential to solubilize hydrocarbon contaminants and...utilize secreted biosurfactants to solubilize the alkanes prior to metabolizing them (Rauch, 2008). Unfortunately, the biosurfactants have deleterious

  5. Enhanced degradation of bioremediation residues in petroleum-contaminated soil using a two-liquid-phase bioslurry reactor.

    Science.gov (United States)

    Lu, Mang; Zhang, Zhongzhi; Sun, Shanshan; Wang, Qinfang; Zhong, Weizhang

    2009-09-01

    A study was performed to determine the potential of two-liquid-phase (TLP) bioslurry reactors using silicon oil as solvent for degradation of residual contaminants in petroleum-contaminated soil. The residues were characterized by gas chromatography-mass spectrometry and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. This allowed for the identification of a mixture of residual biomarkers, metabolic byproducts, oxygenated and hetero-polynuclear aromatic hydrocarbons in the contaminated soil. The removal amount of total extractable organics (TEO) was 15900mgkg(-1) soil in the TLP reactor within 12weeks. However, TEO remained intact in the bioslurry reactor without the addition of silicon oil for the duration of the experiment, due to high toxicity of metabolites to the microorganisms. The availability of TEO was calculated using a mild extraction with Triton X-100, and the amount of TEO extracted was in accord with the amount of biodegraded TEO. Significantly reduced toxicity in soil was observed at week 12 through TLP remediation. Dehydrogenase activity in the bioslurry reactor was strongly suppressed. Fluorescein diacetate was significantly hydrolyzed by the composition of bioremediation residues in the contaminated soil. Microbial adhesion to the solvent was revealed by the determination of microbial activity in the water-immiscible-liquid.

  6. MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2015-08-01

    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  7. Metabolic engineering for the production of hydrocarbon fuels.

    Science.gov (United States)

    Lee, Sang Yup; Kim, Hye Mi; Cheon, Seungwoo

    2015-06-01

    Biofuels have been attracting increasing attention to provide a solution to the problems of climate change and our dependence on limited fossil oil. During the last decade, metabolic engineering has been performed to develop superior microorganisms for the production of so called advanced biofuels. Among the advanced biofuels, hydrocarbons possess high-energy content and superior fuel properties to other biofuels, and thus have recently been attracting much research interest. Here we review the recent advances in the microbial production of hydrocarbon fuels together with the metabolic engineering strategies employed to develop their production strains. Strategies employed for the production of long-chain and short-chain hydrocarbons derived from fatty acid metabolism along with the isoprenoid-derived hydrocarbons are reviewed. Also, the current limitations and future prospects in hydrocarbon-based biofuel production are discussed.

  8. Assessing impediments to hydrocarbon biodegradation in weathered contaminated soils.

    Science.gov (United States)

    Adetutu, Eric; Weber, John; Aleer, Sam; Dandie, Catherine E; Aburto-Medina, Arturo; Ball, Andrew S; Juhasz, Albert L

    2013-10-15

    In this study, impediments to hydrocarbon biodegradation in contaminated soils were assessed using chemical and molecular methodologies. Two long-term hydrocarbon contaminated soils were utilised which were similar in physico-chemical properties but differed in the extent of hydrocarbon (C10-C40) contamination (S1: 16.5 g kg(-1); S2: 68.9 g kg(-1)). Under enhanced natural attenuation (ENA) conditions, hydrocarbon biodegradation was observed in S1 microcosms (26.4% reduction in C10-C40 hydrocarbons), however, ENA was unable to stimulate degradation in S2. Although eubacterial communities (PCR-DGGE analysis) were similar for both soils, the alkB bacterial community was less diverse in S2 presumably due to impacts associated with elevated hydrocarbons. When hydrocarbon bioaccessibility was assessed using HP-β-CD extraction, large residual concentrations remained in the soil following the extraction procedure. However, when linear regression models were used to predict the endpoints of hydrocarbon degradation, there was no significant difference (P>0.05) between HP-β-CD predicted and microcosm measured biodegradation endpoints. This data suggested that the lack of hydrocarbon degradation in S2 resulted primarily from limited hydrocarbon bioavailability. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Availability of polycyclic aromatic hydrocarbons in aging soils

    Energy Technology Data Exchange (ETDEWEB)

    Ling Wanting; Zeng Yuechun; Gao Yanzheng; Dang Hongjiao; Zhu Xuezhu [Coll. of Resource and Environmental Sciences, Nanjing Agricultural Univ. (China)

    2010-07-15

    Purpose: The soil contamination by hydrophobic organic contaminants (HOCs), such as polycyclic aromatic hydrocarbons (PAHs), poses great threats to human health and ecological security and attracts worldwide concerns. The total HOC concentrations overestimate its available fraction to the soil biota. Increased understanding of the availabilities of PAHs in soil environment will have considerable benefits for their risk assessment and be very instructive to food safety and remediation strategies in contaminated sites. However, the availability of PAHs in aging soils and particularly the correlations of the availabilities with their forms in soils have yet to be elucidated. In this work, the availabilities of PAHs in aging soils were evaluated using a sequential mild extraction technique. Materials and methods: Four typical zonal soils in China previously free of PAHs were collected from A (0-20 cm) horizon, air-dried, and sieved. Soils were spiked with a solution of phenanthrene and pyrene as representative PAHs in acetone. After the acetone evaporated off, the treated soils were progressively diluted with unspiked soils and sieved again several times to homogenize the soil samples. The forms of PAHs in soils were experimented using microcosms that are similar to those reported in literature. Various treated soils were packed into amber glass microcosms (each with 25 g soil). Three replications were given for each treatment. NaN{sub 3} solution (0.5%) was added to some microcosms in order to get the microbe-inhibited treatments. The soil water contents were adjusted to be 20% of soil water-holding capacity. After incubation for 0, 2, 4, 8, 12, and 16 weeks in microcosms with a temperature of 25 C, the soils were sampled. PAHs were then extracted by a sequential mild extraction technique, and their forms and availabilities were determined. Results and discussion: The available residual concentrations of phenanthrene and pyrene generally decreased with aging time, and

  10. Combining HPLC-GCXGC, GCXGC/ToF-MS, and selected ecotoxicity assays for detailed monitoring of petroleum hydrocarbon degradation in soil and leaching water.

    Science.gov (United States)

    Mao, Debin; Lookman, Richard; Van De Weghe, Hendrik; Weltens, Reinhilde; Vanermen, Guido; De Brucker, Nicole; Diels, Ludo

    2009-10-15

    HPLC-GCXGC/FID (high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography with flame-ionization detection) and GCXGC/ToF-MS (comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry) were used to study the biodegradation of petroleum hydrocarbons in soil microcosms during 20 weeks. Two soils were studied: one spiked with fresh diesel and one field sample containing weathered diesel-like oil. Nutrient amended and unamended samples were included. Total petroleum hydrocarbon (TPH) levels in spiked soil decreased from 15,000 to 7,500 mg/kg d.m. and from 12,0O0 to 4,000 mg/kg d.m. in the field soil. Linear alkanes and aromatic hydrocarbons were better biodegradable (>60% degraded) than iso-alkanes; cycloalkanes were least degradable (water showed that initially various oxygenated hydrocarbons were produced. Compound peaks seemed to move up and rightward in the GCXGC chromatograms, indicating that more polar and heavier compounds were formed as biodegradation proceeded. Nutrient amendment can increase TPH removal rates, but had adverse effects on ecotoxicity and leaching potential in our experiment This was explained by observed shifts in the soil microbial community. Ecotoxicity assays showed that residual TPH still inhibited cress (Lepidium sativum) seed germination, but the leaching water was no longer toxic toward luminescent bacteria (Vibrio fischeri).

  11. Nitrogen deposition promotes the production of new fungal residues but retards the decomposition of old residues in forest soil fractions.

    Science.gov (United States)

    Griepentrog, Marco; Bodé, Samuel; Boeckx, Pascal; Hagedorn, Frank; Heim, Alexander; Schmidt, Michael W I

    2014-01-01

    Atmospheric nitrogen (N) deposition has frequently been observed to increase soil carbon (C) storage in forests, but the underlying mechanisms still remain unclear. Changes in microbial community composition and substrate use are hypothesized to be one of the key mechanisms affected by N inputs. Here, we investigated the effects of N deposition on amino sugars, which are used as biomarkers for fungal- and bacterial-derived microbial residues in soil. We made use of a 4-year combined CO2 enrichment and N deposition experiment in model forest ecosystems, providing a distinct (13) C signal for 'new' and 'old' C in soil organic matter and microbial residues measured in density and particle-size fractions of soils. Our hypothesis was that N deposition decreases the amount of fungal residues in soils, with the new microbial residues being more strongly affected than old residues. The soil fractionation showed that organic matter and microbial residues are mainly stabilized by association with soil minerals in the heavy and fine fractions. Moreover, the bacterial residues are relatively enriched at mineral surfaces compared to fungal residues. The (13) C tracing indicated a greater formation of fungal residues compared to bacterial residues after 4 years of experiment. In contradiction to our hypotheses, N deposition significantly increased the amount of new fungal residues in bulk soil and decreased the decomposition of old microbial residues associated with soil minerals. The preservation of old microbial residues could be due to decreased N limitation of microorganisms and therefore a reduced dependence on organic N sources. This mechanism might be especially important in fine heavy fractions with low C/N ratios, where microbial residues are effectively protected from decomposition by association with soil minerals.

  12. A Field Scale Investigation of Enhanced Petroleum Hydrocarbon Biodegradation in the Vadose Zone Combining Soil Venting as an Oxygen Source with Moisture and Nutrient Addition

    Science.gov (United States)

    1990-01-01

    microbial degradation of petroleum hydrocarbons has been extensively studied and well documented in the literature. A review of one computer database...Report AMXTH-TE-TR- 85026. U. S. Army Toxic and Hazardous Materials Agency. Edgewood, MD. Atlas, R. M. 1981. Microbial degradation of petroleum hydrocarbons : An

  13. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  14. Root Exudation: The Ecological Driver of Hydrocarbon Rhizoremediation

    Directory of Open Access Journals (Sweden)

    Fanny Rohrbacher

    2016-03-01

    Full Text Available Rhizoremediation is a bioremediation technique whereby microbial degradation of organic contaminants occurs in the rhizosphere. It is considered to be an effective and affordable “green technology” for remediating soils contaminated with petroleum hydrocarbons. Root exudation of a wide variety of compounds (organic, amino and fatty acids, carbohydrates, vitamins, nucleotides, phenolic compounds, polysaccharides and proteins provide better nutrient uptake for the rhizosphere microbiome. It is thought to be one of the predominant drivers of microbial communities in the rhizosphere and is therefore a potential key factor behind enhanced hydrocarbon biodegradation. Many of the genes responsible for bacterial adaptation in contaminated soil and the plant rhizosphere are carried by conjugative plasmids and transferred among bacteria. Because root exudates can stimulate gene transfer, conjugation in the rhizosphere is higher than in bulk soil. A better understanding of these phenomena could thus inform the development of techniques to manipulate the rhizosphere microbiome in ways that improve hydrocarbon bioremediation.

  15. Hydrocarbon geochemistry of cold seeps in the Monterey Bay National Marine Sanctuary

    Science.gov (United States)

    Lorenson, T.D.; Kvenvolden, K.A.; Hostettler, F.D.; Rosenbauer, R.J.; Orange, D.L.; Martin, J.B.

    2002-01-01

    Samples from four geographically and tectonically discrete cold seeps named Clam Flat, Clamfield, Horseshoe Scarp South, and Tubeworm City, within the Monterey Bay National Marine Sanctuary were analyzed for their hydrocarbon content. The sediment contains gaseous hydrocarbons and CO2, as well as high molecular weight aliphatic and aromatic hydrocarbons with various combinations of thermogenic and biogenic contributions from petroleum, marine, and terrigenous sources. Of particular interest is the cold seep site at Clamfield which is characterized by the presence of thermogenic hydrocarbons including oil that can likely be correlated with oil-saturated strata at Majors Creek near Davenport, CA, USA. At Clam Flat, the evidence for thermogenic hydrocarbons is equivocal. At Horseshoe Scarp South and Tubeworm City, hydrocarbon gases, mainly methane, are likely microbial in origin. These varied sources of hydrocarbon gases highlight the diverse chemical systems that appear at cold seep communities. ?? 2002 Elsevier Science B.V. All rights reserved.

  16. Biofilm comprising phototrophic, diazotrophic, and hydrocarbon-utilizing bacteria: a promising consortium in the bioremediation of aquatic hydrocarbon pollutants.

    Science.gov (United States)

    Al-Bader, Dhia; Kansour, Mayada K; Rayan, Rehab; Radwan, Samir S

    2013-05-01

    Biofilms harboring simultaneously anoxygenic and oxygenic phototrophic bacteria, diazotrophic bacteria, and hydrocarbon-utilizing bacteria were established on glass slides suspended in pristine and oily seawater. Via denaturing gradient gel electrophoresis analysis on PCR-amplified rRNA gene sequence fragments from the extracted DNA from biofilms, followed by band amplification, biofilm composition was determined. The biofilms contained anoxygenic phototrophs belonging to alphaproteobacteria; pico- and filamentous cyanobacteria (oxygenic phototrophs); two species of the diazotroph Azospirillum; and two hydrocarbon-utilizing gammaproteobacterial genera, Cycloclasticus and Oleibacter. The coexistence of all these microbial taxa with different physiologies in the biofilm makes the whole community nutritionally self-sufficient and adequately aerated, a condition quite suitable for the microbial biodegradation of aquatic pollutant hydrocarbons.

  17. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

    Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of

  18. Oxygenated Derivatives of Hydrocarbons

    Science.gov (United States)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  19. Hydrocarbon Spectral Database

    Science.gov (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  20. Metagenomics of hydrocarbon resource environments indicates aerobic taxa and genes to be unexpectedly common.

    Science.gov (United States)

    An, Dongshan; Caffrey, Sean M; Soh, Jung; Agrawal, Akhil; Brown, Damon; Budwill, Karen; Dong, Xiaoli; Dunfield, Peter F; Foght, Julia; Gieg, Lisa M; Hallam, Steven J; Hanson, Niels W; He, Zhiguo; Jack, Thomas R; Klassen, Jonathan; Konwar, Kishori M; Kuatsjah, Eugene; Li, Carmen; Larter, Steve; Leopatra, Verlyn; Nesbø, Camilla L; Oldenburg, Thomas; Pagé, Antoine P; Ramos-Padron, Esther; Rochman, Fauziah F; Saidi-Mehrabad, Alireeza; Sensen, Christoph W; Sipahimalani, Payal; Song, Young C; Wilson, Sandra; Wolbring, Gregor; Wong, Man-Ling; Voordouw, Gerrit

    2013-09-17

    Oil in subsurface reservoirs is biodegraded by resident microbial communities. Water-mediated, anaerobic conversion of hydrocarbons to methane and CO2, catalyzed by syntrophic bacteria and methanogenic archaea, is thought to be one of the dominant processes. We compared 160 microbial community compositions in ten hydrocarbon resource environments (HREs) and sequenced twelve metagenomes to characterize their metabolic potential. Although anaerobic communities were common, cores from oil sands and coal beds had unexpectedly high proportions of aerobic hydrocarbon-degrading bacteria. Likewise, most metagenomes had high proportions of genes for enzymes involved in aerobic hydrocarbon metabolism. Hence, although HREs may have been strictly anaerobic and typically methanogenic for much of their history, this may not hold today for coal beds and for the Alberta oil sands, one of the largest remaining oil reservoirs in the world. This finding may influence strategies to recover energy or chemicals from these HREs by in situ microbial processes.

  1. Petroleum Hydrocarbon Degradation Potential of Soil Bacteria Native to the Yellow River Delta

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-Yu; GAO Dong-Mei; LI Feng-Min; ZHAO Jian; XIN Yuan-Zheng; S.SIMKINS; XING Bao-Shan

    2008-01-01

    The bioremediation potential of bacteria indigenous to soils of the Yellow River Delta in China was evaluated as a treatment option for soil remediation. Petroleum hydrocarbon degraders were isolated from contaminated soil samples from the Yellow River Delta. Four microbial communities and eight isolates were obtained. The optimal temperature, salinity, pH, and the ratios of C, N, and P (C:N:P) for the maximum biodegradation of diesel oil, crude oil, n-alkanes, and polyaromatic hydrocarbons by ndigenous bacteria were determined, and the kinetics changes in microbial communities were monitored. In general, the mixed microbial consortia demonstrated wider catabolic versatility and faster overall rate of hydrocarbon degradation than individual isolates. Our experimental results demonstrated the feasibility of biodegradation of petroleum hydrocarbon by indigenous bacteria for oil remediation in the Yellow River Delta.

  2. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  3. Plant hydrocarbon recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

    1982-01-26

    A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

  4. Identification and biodegradation potential of tropical aerobic hydrocarbon-degrading microorganisms.

    Science.gov (United States)

    Chaillan, Frédéric; Le Flèche, Anne; Bury, Edith; Phantavong, Y-Hui; Grimont, Patrick; Saliot, Alain; Oudot, Jean

    2004-09-01

    Screening of aerobic culturable hydrocarbon (HC)-degrading microorganisms isolated from petroleum-polluted soils and cyanobacterial mats from Indonesia resulted in the collection of 33 distinct species. Eight bacteria, 21 fungi and 4 yeasts were identified to the specific level by molecular and phenotypic techniques. Bacterial strains belonged to the genera Gordonia, Brevibacterium, Aeromicrobium, Dietzia, Burkholderia and Mycobacterium. Four species are new and not yet described. Fungi belonged to Aspergillus, Penicillium, Fusarium, Amorphoteca, Neosartorya, Paecilomyces, Talaromyces and Graphium. Yeasts were Candida, Yarrowia and Pichia. All strains were cultivated axenically in synthetic liquid media with crude oil as sole carbon and energy source. After incubation, the detailed chemical composition of the residual oil was studied by gravimetric and gas-chromatographic techniques. Thirteen parameters for assessing the biodegradation potential were defined and computed for each strain. Maximum degradation was observed on the saturated HCs (n- and isoalkanes, isoprenoids), whereas aromatic HC degradation was lower and was related to the structural composition of the molecules. A principal components analysis (PCA) permitted grouping and classifying the strains as a function of their degradative capacities. It was shown that the most active strains produced polar metabolites which accumulated in the resins and asphaltene fractions. These fractions are highly resistant to microbial metabolism. No taxonomic trend could be defined between microbial phyla in terms of HC biodegradation activity.

  5. Methanogenic biodegradation of paraffinic solvent hydrocarbons in two different oil sands tailings.

    Science.gov (United States)

    Mohamad Shahimin, Mohd Faidz; Siddique, Tariq

    2017-04-01

    Microbial communities drive many biogeochemical processes in oil sands tailings and cause greenhouse gas emissions from tailings ponds. Paraffinic solvent (primarily C5-C6; n- and iso-alkanes) is used by some oil sands companies to aid bitumen extraction from oil sands ores. Residues of unrecovered solvent escape to tailings ponds during tailings deposition and sustain microbial metabolism. To investigate biodegradation of hydrocarbons in paraffinic solvent, mature fine tailings (MFT) collected from Albian and CNRL ponds were amended with paraffinic solvent at ~0.1wt% (final concentration: ~1000mgL(-1)) and incubated under methanogenic conditions for ~1600d. Albian and CNRL MFTs exhibited ~400 and ~800d lag phases, respectively after which n-alkanes (n-pentane and n-hexane) in the solvent were preferentially metabolized to methane over iso-alkanes in both MFTs. Among iso-alkanes, only 2-methylpentane was completely biodegraded whereas 2-methylbutane and 3-methylpentane were partially biodegraded probably through cometabolism. 16S rRNA gene pyrosequencing showed dominance of Anaerolineaceae and Methanosaetaceae in Albian MFT and Peptococcaceae and co-domination of "Candidatus Methanoregula" and Methanosaetaceae in CNRL MFT bacterial and archaeal communities, respectively, during active biodegradation of paraffinic solvent. The results are important for developing future strategies for tailings reclamation and management of greenhouse gas emissions.

  6. 计算机重构石油烃降解的微生物代谢途径%Computational Reconstruction of Microbial Pathways for Degradation of Petroleum Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    王东; 何涛; 邵卫东; 汪莉; 王玉民

    2012-01-01

    目的:用计算机重构石油烃降解通路,为石油污染的生物修复提供理论依据.方法:利用KEGG反应、化合物数据提取反应等式,过滤掉所有反应中的通用化合物及小分子化合物并构建反应矩阵,然后利用广度优先搜索算法在反应矩阵中搜索降解石油烃的代谢途径.结果:计算机分别重构了256 132条链烷烃降解途径和44条环己烷降解途径,以酿酒酵母作为降解石油烃的基因工程菌为例,通过限制改构菌整合的关键酶数目,分别得到了213条不需要转入关键酶的链烷烃降解通路和6条以氧化还原酶、松柏醇脱氢酶或环己醇脱氢酶和环己酮单氧酶为关键酶的环己烷降解通路,并构建相应的降解网络图,标注每个反应的酶.结论:应用计算机重构了2种石油烃降解途径,可为利用微生物对石油污染进行生物修复提供理论依据.%Objective: Metabolic pathways for degradation of petroleum hydrocarbons were reconstructed by computational skills to provide theoretical basis for the bioremediation of oil polution. Methods: At first, the reaction equations were extracted from the KEGC reaction database and the compound database. And then current metabolites and micromolecule compounds in all the reactions were filtered out. Finally, the reaction matrix was constructed to search metabolic pathways for degrading petroleum hydrocarbons by the breadth first search approach. Results: 256 132 pathways for degrading alkanes and 44 pathways for degrading cyclohexane were reconstructed by computational skills. Taking Saccharomyces cerevisiae as the genetic engineering bacteria, we picked out 219 pathways by limiting the number of pivotal enzymes to construct the metabolic network, including 213 pathways without key enzymes and 6 pathways with oxidoreductases, coniferyl alcohol dehydrogenase or cyclohexanol dehydroge-nase and cyclohexanone monooxygenase as key enzymes. Catalytic enzymes of every reaction

  7. Reclamation of DPK hydrocarbon polluted agricultural soil using a selected bulking agent.

    Science.gov (United States)

    Nwankwegu, Amechi S; Onwosi, Chukwudi O; Orji, Michael U; Anaukwu, Chika G; Okafor, Uchenna C; Azi, Fidelis; Martins, Paul E

    2016-05-01

    In the present study, laboratory scale bioremediation of dual purpose kerosene (DPK) hydrocarbon polluted soil using bulking agent (saw dust) was carried out. The effect of different parameters such as total petroleum hydrocarbon (TPH), dehydrogenase activity (DHase) and pH on bioremediation performance were evaluated. Studied parameters such as microbial dynamics, percentage degradation (95.20%), DHase (8.20 ± 0.43) were found to be higher in saw dust amended system and significantly differed with control at p hydrocarbon clean up. Therefore, saw dust could serve as an effective biostimulant towards improved bioremediation of hydrocarbon polluted environment.

  8. HYDROTHERMAL CRACKING OF RESIDUAL OILS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrothermal cracking of heavy oils, such as Canadian oil sand bitumen and Arabian heavy vacuum residue, as well as their model compound were performed over sulfided Ni/Al2O3 and NiMo/Al2O3 catalysts under 663~703 K and 6.0~8.0 MPa of hydrogen pressure in a batch autoclave reactor. According to the reaction mechanism of hydrothermal cracking, a small amount of free redical initiators, such as di-tert-peroxide, sulfur, etc., was added into the feed to generate free redicals at lower temperature, and obviously showed promotional effect on the conversion of hydrocarbons. The reaction mechanisms of hydrothermal cracking as well as the enhancing effect of initiators were studied by a probe reaction with 1-phenyldodecane as a model compound. The hydrothermal cracking of hydrocarbon proceeded via free redical mechanism and hydrogenating quench. The initiators might easily generate free redicals under reaction temperature, these redicals might abstract H from hydrocarbon molecule and reasonably initiate the chain reactions, therefore, promote the conversion of hydrocarbon even at lower reaction temperature.

  9. Source apportionment of sediment-associated aliphatic hydrocarbon in a eutrophicated shallow lake, China.

    Science.gov (United States)

    Wang, Ji-Zhong; Yang, Ze-Yu; Chen, Tian-Hu

    2012-11-01

    Chaohu Lake, one of the most eutrophicated lakes in China, has been suffering from long-term outside pollution, urban sewage, river outflows, and agricultural runoff which expectedly have been the main contributors of hydrocarbons. However, the contributions from these various sources have not been specified. The present study is aimed at identifying the potential sources of hydrocarbons in surface sediment around the whole lake and assessing the relative contributions using principal components analysis-multiple linear regression (PCA-MLR). Sixty-one surface sediments covering the whole Chaohu Lake and three main estuaries of inflowing rivers were collected, dried, extracted, and analyzed for 27 normal alkanes (n-alkanes, from C(12) to C(38), defined Σ(27)AH) and unresolved complex mixture (UCM) by GC/MS. Diagnostic ratios and PCA-MLR were utilized to apportion their sources. The concentrations of Σ(27)AH and UCM ranged from 434 to 3,870 ng/g and 11.9 to 325 μg/g dry weight, respectively, for all samples. The concentrations of Σ(27)AH in western region and estuary of Nanfei River were slightly higher but without statistical significance than those from eastern region and estuaries of Yuxi River and Hangbu River. The concentration of UCM from western region was significantly higher than that obtained from eastern region. These results reflect the importance of input of urban runoff by Nanfei River and serious eutrophication in western region. Aliphatic hydrocarbons in Chaohu Lake were mainly derived from high plant wax with mixed sources of phytoplankton and petroleum. Weak microbial decomposition of n-alkanes would be expected to occur from the low ratios of isoprenoid hydrocarbons pristine (pri) and phytane (phy) to n-C(17) and n-C(18), respectively. Higher plant, fossil combustion, petroleum residue, and phytoplankton were proposed as the main origines of aliphatic hydrocarbons by PCA while the contributions of individual n-alkane homologues, pri and phy

  10. Conversion of Crude Oil to Methane by a Microbial Consortium Enriched From Oil Reservoir Production Waters

    Directory of Open Access Journals (Sweden)

    Carolina eBerdugo-Clavijo

    2014-05-01

    Full Text Available The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls, corresponding to the detection of an alkyl succinate synthase gene (assA in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic versus sessile within a subsurface crude oil reservoir.

  11. Microbial populations related to PAH biodegradation in an aged biostimulated creosote-contaminated soil.

    Science.gov (United States)

    Lladó, Salvador; Jiménez, Nuria; Viñas, Marc; Solanas, Anna Maria

    2009-09-01

    A previous bioremediation survey on a creosote-contaminated soil showed that aeration and optimal humidity promoted depletion of three-ringed polycyclic aromatic hydrocarbons (PAHs), but residual concentrations of four-ringed benzo(a)anthracene (B(a)A) and chrysene (Chry) remained. In order to explain the lack of further degradation of heavier PAHs such as four-ringed PAHs and to analyze the microbial population responsible for PAH biodegradation, a chemical and microbial molecular approach was used. Using a slurry incubation strategy, soil in liquid mineral medium with and without additional B(a)A and Chry was found to contain a powerful PAH-degrading microbial community that eliminated 89% and 53% of the added B(a)A and Chry, respectively. It is hypothesized that the lack of PAH bioavailability hampered their further biodegradation in the unspiked soil. According to the results of the culture-dependent and independent techniques Mycobacterium parmense, Pseudomonas mexicana, and Sphingobacterials group could control B(a)A and Chry degradation in combination with several microorganisms with secondary metabolic activity.

  12. Approaches to In Situ Characterization of Microbial Degradation of Polycyclic Aromatic Hydrocarbons (PAHs)%多环芳烃(PAHs)微生物降解的原位表征方法

    Institute of Scientific and Technical Information of China (English)

    陈松灿; 段桂兰; 朱永官

    2015-01-01

    多环芳烃(polycyclic aromatic hydrocarbons,PAHs)是一类在环境中广泛存在的持久性有机污染物,微生物降解是去除环境中多环芳烃污染的主要途径.传统的有关PAHs微生物降解的研究主要依靠分离培养技术,难以准确认识PAHs微生物降解的原位过程及机制.近年来发展起来的原位表征方法可以在基因及单细胞水平研究PAHs在复杂环境中的微生物降解过程,能够原位表征具有PAHs降解功能的微生物及其功能基因和代谢活性,是阐明PAHs原位降解过程及分子机制的强有力的手段.该文综述了宏基因组技术(meta-genomics)、稳定同位素探针技术(stable isotopeprobe,SIP)、荧光原位杂交技术(fluorescence in situ hybridization,FISH)、拉曼光谱技术(Raman spectra)以及二次离子质谱技术(secondary ion mass spectrometry,SIMS)等原位表征技术在PAHs微生物降解研究领域的应用及其存在的问题和发展趋势等.PAHs微生物降解过程及机制的原位表征将为缓解与修复PAHs污染提供科学基础.

  13. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Although thraustochytrid protists are known to be of widespread occurrence in the sea, their hydrocarbon-degrading abilities have never been investigated. We isolated thraustochytrids from coastal waters and sediments of Goa coast by enriching MPN...

  14. Soil bioremediation approaches for petroleum hydrocarbon polluted environments

    Directory of Open Access Journals (Sweden)

    Eman Koshlaf

    2017-01-01

    Full Text Available Increasing industrialisation, continued population growth and heavy demand and reliance on petrochemical products have led to unprecedented economic growth and development. However, inevitably this dependence on fossil fuels has resulted in serious environmental issues over recent decades. The eco-toxicity and the potential health implications that petroleum hydrocarbons pose for both environmental and human health have led to increased interest in developing environmental biotechnology-based methodologies to detoxify environments impacted by petrogenic compounds. Different approaches have been applied for remediating polluted sites with petroleum derivatives. Bioremediation represents an environmentally sustainable and economical emerging technology for maximizing the metabolism of organic pollutants and minimizing the ecological effects of oil spills. Bioremediation relies on microbial metabolic activities in the presence of optimal ecological factors and necessary nutrients to transform organic pollutants such as petrogenic hydrocarbons. Although, biodegradation often takes longer than traditional remediation methods, the complete degradation of the contaminant is often accomplished. Hydrocarbon biodegradation in soil is determined by a number of environmental and biological factors varying from site to site such as the pH of the soil, temperature, oxygen availability and nutrient content, the growth and survival of hydrocarbon-degrading microbes and bioavailability of pollutants to microbial attack. In this review we have attempted to broaden the perspectives of scientists working in bioremediation. We focus on the most common bioremediation technologies currently used for soil remediation and the mechanisms underlying the degradation of petrogenic hydrocarbons by microorganisms.

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

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

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

  16. Bioaccessible Porosity: A new approach to assess residual contamination after bioremediation of hydrophobic organic compounds in sub-surface microporous environments

    Science.gov (United States)

    Akbari, A.; Ghoshal, S.

    2016-12-01

    We define a new parameter, "bioaccessible porosity", the fraction of aggregate volume accessible to soil bacteria, towards a priori assessment of hydrocarbon bioremediation end points. Microbial uptake of poorly soluble hydrocarbons occurs through direct uptake or micellar solubilzation/emulsification associated with biosurfactant production, and requires close proximity of bacteria and hydrocarbon phase. In subsurface microporous environments, bioremediation rates are attenuated when residual hydrophobic contamination is entrapped in sterically restrictive environments which is not accessible to soil bacteria. This study presents new approaches for characterization of the microstructure of porous media and as well, the ability of indigenous hydrocarbon degraders to access to a range of pore sizes. Bacterial access to poorly soluble hydrocarbons in soil micro pores were simulated with bioreactors with membranes with different pore sizes containing the hydrocarbon degrading bacteria, Dietzia maris. D. maris is Gram-positive, and nonmotile that we isolated as the major hydrocarbon degrader from a fine-grained, weathered, hydrocarbon-contaminated site soil. Under nutritional stress, planktonic D. maris cells were aggregated and accessed 5 µm but not 3 µm and smaller pores. However, when hexadecane was available at the pore mouth, D. maris colonized the pore mouth, and accessed pores as small as 0.4 µm. This suggests bacterial accessibility to different pore sizes is regulated by nutritional conditions. A combination of X-ray micro-CT scanning, gas adsorption and mercury intrusion porosimetry was used to characterize the range of pore sizes of soil aggregates. In case of the studied contaminated soil, the bioaccessible porosity were determined as 25% , 27% and 29% (assuming 4, 1, 0.4 µm respectively as accessibility criteria), and about 2.7% of aggregate volume was attributed to 0.006-0.4 µm pores. The 2% aggregate volume at an assumed saturation of 10% could

  17. Use of Advanced Oxidation and Aerobic Degradation for Remediation of Various Hydrocarbon Contaminates

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-03-06

    Western Research Institute in conjunction with Sierra West Consultants, Inc., Tetra Tech, Inc., and the U.S. Department of Energy conducted laboratory and field studies to test different approaches to enhance degradation of hydrocarbons and associated contaminants. WRI in conjunction with Sierra West Consultants, Inc., conducted a laboratory and field study for using ozone to treat a site contaminated with MTBE and other hydrocarbons. Results from this study demonstrate that a TOD test can be used to resolve the O{sub 3} dosage problem by establishing a site-specific benchmark dosage for field ozone applications. The follow-up testing of the laboratory samples provided indications that intrinsic biodegradation could be stimulated by adding oxygen. Laboratory studies also suggests that O3 dosage in the full-scale field implementation could be dialed lower than stoichiometrically designed to eliminate the formation of Cr(VI). WRI conducted a study involving a series of different ISCO oxidant applications to diesel-contaminated soil and determined the effects on enhancing biodegradation to degrade the residual hydrocarbons. Soils treated with permanganate followed by nutrients and with persulfate followed by nutrients resulted in the largest decrease in TPH. The possible intermediates and conditions formed from NOM and TPH oxidation by permanganate and activated persulfate favors microbial TPH degrading activity. A 'passive-oxidation' method using microbial fuel cell (MFC) technology was conducted by WRI in conjunction with Tetra Tech, Inc., to degrade MTBE in groundwater. These experiments have demonstrated that a working MFC (i.e., one generating power) could be established in the laboratory using contaminated site water or buffered media inoculated with site water and spiked with MTBE, benzene, or toluene. Electrochemical methods were studied by WRI with goal of utilizing low voltage and amperage electrical sources for 'geo-oxidation' of organic

  18. Characterization of Petroleum Hydrocarbon Decomposing Fungi Isolated from Mangrove Rhizosphere

    Directory of Open Access Journals (Sweden)

    Nuni Gofar

    2011-01-01

    Full Text Available The research was done to obtain the isolates of soil borne fungi isolated from mangrove rhizosphere which were capable of degrading petroleum hydrocarbon compounds. The soil samples were collected from South Sumatra mangrove forest which was contaminated by petroleum. The isolates obtained were selected based on their ability to survive, to grow and to degrade polycyclic aromatic hydrocarbons in medium containing petroleum residue. There were 3 isolates of soil borne hydrocarbonoclastic fungi which were able to degrade petroleum in vitro. The 3 isolates were identified as Aspergillus fumigates, A. parasiticus, and Chrysonilia sitophila. C. sitophila was the best isolate to decrease total petroleum hydrocarbon (TPH from medium containing 5-20% petroleum residue.

  19. Detection and Origin of Hydrocarbon Seepage Anomalies in the Barents Sea

    Science.gov (United States)

    Polteau, Stephane; Planke, Sverre; Stolze, Lina; Kjølhamar, Bent E.; Myklebust, Reidun

    2016-04-01

    We have collected more than 450 gravity cores in the Barents Sea to detect hydrocarbon seepage anomalies and for seismic-stratigraphic tie. The cores are from the Hoop Area (125 samples) and from the Barents Sea SE (293 samples). In addition, we have collected cores near seven exploration wells. The samples were analyzed using three different analytical methods; (1) the standard organic geochemical analyzes of Applied Petroleum Technologies (APT), (2) the Amplified Geochemical Imaging (AGI) method, and (3) the Microbial Prospecting for Oil and Gas (MPOG) method. These analytical approaches can detect trace amounts of thermogenic hydrocarbons in the sediment samples, and may provide additional information about the fluid phases and the depositional environment, maturation, and age of the source rocks. However, hydrocarbon anomalies in seabed sediments may also be related to shallow sources, such as biogenic gas or reworked source rocks in the sediments. To better understand the origin of the hydrocarbon anomalies in the Barents Sea we have studied 35 samples collected approximately 200 m away from seven exploration wells. The wells included three boreholes associated with oil discoveries, two with gas discoveries, one dry well with gas shows, and one dry well. In general, the results of this case study reveal that the oil wells have an oil signature, gas wells show a gas signature, and dry wells have a background signature. However, differences in results from the three methods may occur and have largely been explained in terms of analytical measurement ranges, method sensitivities, and bio-geochemical processes in the seabed sediments. The standard geochemical method applied by APT relies on measuring the abundance of compounds between C1 to C5 in the headspace gas and between C11 to C36 in the sediment extracts. The anomalies detected in the sediment samples from this study were in the C16 to C30 range. Since the organic matter yields were mostly very low, the

  20. Comparison between different bio-treatments of a hydrocarbon ...

    African Journals Online (AJOL)

    Ramya

    2011-10-31

    Oct 31, 2011 ... DOI: 10.5897/AJB10.1705. ISSN 1684–5315 © 2011 Academic Journals .... is designed to avoid, reduce, reuse, recycle, recover, treat and dispose of .... water holding capacity) or in this modified nutrient solution. .... (a) i. Figure 1. Average residual total petroleum hydrocarbons (TPH) in different laboratory.

  1. Aeromagnetics of southern Alberta within areas of hydrocarbon accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Leblanc, G. E.; Morris, W. A. [McMaster Univ., School of Geography and Geology, Hamilton, ON (Canada)

    1999-12-01

    The relationship between the observed geomagnetic field and hydrocarbon pools is investigated by reviewing the sources of magnetic anomalies in sedimentary basins and the methods for isolating individual contributions, with specific reference to noise suppression. A recent high resolution aeromagnetic survey acquired by the Geological Survey of Canada in southern Alberta is used as the test case to demonstrate the method and the potential of aeromagnetic surveys to resolve structural controls on hydrocarbon emplacement. The investigation was undertaken in an effort to account for the fact that several features of the residual magnetic field appear to be common to a majority of hydrocarbon pools. Some of these commonalities are: (1) the long axis of the pool appears to be coincident with the strike of the basement-sourced magnetic signal, (2) hydrocarbon pools encompass areas of broad low amplitude magnetic anomalies, (3) cross-cutting fractures or faulting systems are located within areas of a majority of hydrocarbon pools, and (4) pools are associated with linear and/or curvilinear magnetic lineaments, of which a great number have topographic expression. These associations may arise as a result of eH/pH conditions of the hydrocarbons and the surrounding sediments, or they may arise purely as a result of the trapping structures. The physical extent of the interaction area of the pool with the surrounding sediment may be another factor in explaining the association of hydrocarbons and magnetics. 48 refs., 9 figs.

  2. Microbial degradation of monocyclic and polycyclic aromatic hydrocarbons in case of limited pollutant availability with nitrate as a potential electron acceptor; Der mikrobielle Abbau mono- und polyzyklischer aromatischer Kohlenwasserstoffe bei einer begrenzten Schadstoffverfuegbarkeit mit Nitrat als potentiellem Elektronenakzeptor

    Energy Technology Data Exchange (ETDEWEB)

    Linke, C.

    2001-07-01

    The possibility of using natural degradation processes for long-term remediation of tar oil contaminated sites was investigated. Field studies have shown that microbial decomposition of pollutants does take place in many sites but that it is limited by limited availability of pollutants and oxygen in soil. The investigations focused on the activation of BTEX and PAH degradation in situ by nitrate in the absence or in the presence of oxygen. Tensides should be used in order to enhance the availability of pollutants in water, especially in the case of hardly water-soluble PAH. A large-scale experiment was carried out on tar oil contaminated terrain; it was found that the availability of oxygen and not of PAH is the limiting factor so that adding of surfactants will not improve pollutant degradation. In contrast, the adding of tensides would mean even higher concentrations of oxygen-depleting substances in soil. [German] In der vorliegenden Arbeit wurden im Hinblick auf langfristige Sanierungsstrategien fuer teeroelkontaminierte Standorte Moeglichkeiten der Nutzung natuerlicher Abbauvorgaenge untersucht. Zahlreiche Feldstudien belegen, dass ein mikrobieller Schadstoffabbau an vielen Standorten stattfindet, dieser jedoch sowohl durch eine begrenzte Schadstoffverfuegbarkeit als auch durch den im Untergrund nur begrenzt zur Verfuegung stehenden Sauerstoff limitiert wird. Ziel dieser Arbeit war es abzuklaeren, inwiefern ein BTEX- und PAK-Abbau in situ auch in Abwesenheit von Sauerstoff durch Nitrat allein oder durch Nitrat in Kombination mit Sauerstoff aktiviert werden kann. Um insbesondere fuer die schlecht wasserloeslichen PAK eine ausreichende Schadstoffverfuegbarkeit zu gewaehrleisten, sollten auch Tenside zur Erhoehung der im Wasser vorliegenden Schadstoffmenge eingesetzt werden. Aufbauend auf die Laboruntersuchungen wurde im Rahmen von VEGAS{sup ix} ein Grossversuch zum mikrobiellen PAK-Abbau im Abstrom einer simulierten Teeroelkontamination durchgefuehrt

  3. Anaerobic microbial degradation of organic pollutants with chlorate as electron acceptor

    NARCIS (Netherlands)

    Mehboob, F.

    2010-01-01

    Aliphatic and aromatic hydrocarbons are two groups of compounds that are widespread pollutants. The aerobic microbial degradation of aliphatic and aromatic hydrocarbons proceeds in general fast and has been widely studied, while the biodegradation in anoxic environments is often incomplete, proceeds

  4. Abiogenic formation of alkanes in the Earth's crust as a minor source for global hydrocarbon reservoirs

    Science.gov (United States)

    Sherwood Lollar, B.; Westgate, T. D.; Ward, J. A.; Slater, G. F.; Lacrampe-Couloume, G.

    2002-04-01

    Natural hydrocarbons are largely formed by the thermal decomposition of organic matter (thermogenesis) or by microbial processes (bacteriogenesis). But the discovery of methane at an East Pacific Rise hydrothermal vent and in other crustal fluids supports the occurrence of an abiogenic source of hydrocarbons. These abiogenic hydrocarbons are generally formed by the reduction of carbon dioxide, a process which is thought to occur during magma cooling and-more commonly-in hydrothermal systems during water-rock interactions, for example involving Fischer-Tropsch reactions and the serpentinization of ultramafic rocks. Suggestions that abiogenic hydrocarbons make a significant contribution to economic hydrocarbon reservoirs have been difficult to resolve, in part owing to uncertainty in the carbon isotopic signatures for abiogenic versus thermogenic hydrocarbons. Here, using carbon and hydrogen isotope analyses of abiogenic methane and higher hydrocarbons in crystalline rocks of the Canadian shield, we show a clear distinction between abiogenic and thermogenic hydrocarbons. The progressive isotopic trends for the series of C1-C4 alkanes indicate that hydrocarbon formation occurs by way of polymerization of methane precursors. Given that these trends are not observed in the isotopic signatures of economic gas reservoirs, we can now rule out the presence of a globally significant abiogenic source of hydrocarbons.

  5. A polyphasic approach for assessing the suitability of bioremediation for the treatment of hydrocarbon-impacted soil.

    Science.gov (United States)

    Adetutu, Eric M; Smith, Renee J; Weber, John; Aleer, Sam; Mitchell, James G; Ball, Andrew S; Juhasz, Albert L

    2013-04-15

    Bioremediation strategies, though widely used for treating hydrocarbon-contaminated soil, suffer from lack of biodegradation endpoint accountability. To address this limitation, molecular approaches of alkB gene analysis and pyrosequencing were combined with chemical approaches of bioaccessibility and nutrient assays to assess contaminant degrading capacity and develop a strategy for endpoint biodegradation predictions. In long-term hydrocarbon-contaminated soil containing 10.3 g C10-C36 hydrocarbons kg(-1), 454 pyrosequencing detected the overrepresentation of potential hydrocarbon degrading genera such as Pseudomonas, Burkholderia, Mycobacterium and Gordonia whilst amplicons for PCR-DGGE were detected only with alkB primers targeting Pseudomonas. This indicated the presence of potential microbial hydrocarbon degradation capacity in the soil. Using non-exhaustive extraction methods of 1-propanol and HP-β-CD for hydrocarbon bioaccessibility assessment combined with biodegradation endpoint predictions with linear regression models, we estimated 33.7% and 46.7% hydrocarbon removal respectively. These predictions were validated in pilot scale studies using an enhanced natural attenuation strategy which resulted in a 46.4% reduction in soil hydrocarbon content after 320 days. When predicted biodegradation endpoints were compared to measured values, there was no significant difference (P=0.80) when hydrocarbon bioaccessibility was assessed with HP-β-CD. These results indicate that a combination of molecular and chemical techniques that inform microbial diversity, functionality and chemical bioaccessibility can be valuable tools for assessing the suitability of bioremediation strategies for hydrocarbon-contaminated soil.

  6. Les hydrocarbures aromatiques polycycliques dans l'environnement. Deuxième partie : La dégradation par voie microbienne Polycyclic Aromatic Hydrocarbons in the Environment. Part Two: Microbial Degradation

    Directory of Open Access Journals (Sweden)

    Bouchez M.

    2006-11-01

    Full Text Available La microbiologie de la dégradation des hydrocarbures aromatiques polycycliques (HAP est un domaine de recherche en plein développement. C'est à la fois le devenir dans l'environnement de ces composés ubiquistes et génotoxiques et l'utilisation de procédés microbiologiques de dépollution des sols industriels contaminés par ces produits qui motivent cet intérêt. On présente ici une synthèse des connaissances actuelles dans ce domaine. Les organismes dégradeurs sont essentiellement les bactéries et les champignons. Le processus de dégradation, aérobie, est initié par des oxygénases. Les bactéries utilisent les HAP de deux à quatre cycles comme substrats de croissance, ce qui conduit à leur minéralisation. Les champignons, lignolytiques et non lignolytiques, attaquent les HAP par cométabolisme, ce que font également les bactéries. L'ensemble des micro-organismes dégradant les HAP, et les voies métaboliques impliquées, sont présentés. Le mode d'accession des micro-organismes à leurs substrats très peu solubles est un point important. Les études menées avec les bactéries ont montré l'existence de deux mécanismes, le transfert par solubilisation dans la phase aqueuse et l'accession interfaciale directe. Un autre aspect présenté est le devenir des HAP, en termes de bilans carbone, lors de la dégradation bactérienne de HAP individuels et de mélanges de HAP. Des taux de minéralisation élevés peuvent être obtenus. Dans le cas des mélanges, ces taux élevés impliquent la mise en oeuvre de microflores complexes où le cométabolisme joue un rôle important. Les progrès accomplis ces dernières années conduisent à ne plus considérer les HAP comme des composés intrinsèquement récalcitrants à la biodégradation. Dans l'environnement, un facteur important limitant la dégradation des HAP est leur accessibilité aux micro-organismes. The microbiology of the degradation of polycyclic aromatic hydrocarbons

  7. Quantitative Hydrocarbon Surface Analysis

    Science.gov (United States)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  8. Miscellaneous hydrocarbon solvents.

    Science.gov (United States)

    Bebarta, Vikhyat; DeWitt, Christopher

    2004-08-01

    The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed.

  9. Characterisation of the effect of a simulated hydrocarbon spill on diazotrophs in mangrove sediment mesocosm

    OpenAIRE

    Taketani,Rodrigo Gouvêa; dos Santos, Henrique Fragoso; van Elsas, Jan Dirk; Rosado,Alexandre Soares

    2009-01-01

    An analysis of the effect of an oil spill on mangrove sediments was carried out by contamination of mesocosms derived from two different mangroves, one with a history of contamination and one pristine. The association between N2 fixers and hydrocarbon degradation was assessed using quantitative PCR (qPCR) for the genes rrs and nifH, nifH clone library sequencing and total petroleum hydrocarbon (TPH) quantification using gas chromatography. TPH showed that the microbial communities of both man...

  10. Tracking hydrocarbon plume transport and biodegradation at Deepwater Horizon.

    Science.gov (United States)

    Camilli, Richard; Reddy, Christopher M; Yoerger, Dana R; Van Mooy, Benjamin A S; Jakuba, Michael V; Kinsey, James C; McIntyre, Cameron P; Sylva, Sean P; Maloney, James V

    2010-10-08

    The Deepwater Horizon blowout is the largest offshore oil spill in history. We present results from a subsurface hydrocarbon survey using an autonomous underwater vehicle and a ship-cabled sampler. Our findings indicate the presence of a continuous plume of oil, more than 35 kilometers in length, at approximately 1100 meters depth that persisted for months without substantial biodegradation. Samples collected from within the plume reveal monoaromatic petroleum hydrocarbon concentrations in excess of 50 micrograms per liter. These data indicate that monoaromatic input to this plume was at least 5500 kilograms per day, which is more than double the total source rate of all natural seeps of the monoaromatic petroleum hydrocarbons in the northern Gulf of Mexico. Dissolved oxygen concentrations suggest that microbial respiration rates within the plume were not appreciably more than 1 micromolar oxygen per day.

  11. Use of biological activities to monitor the removal of fuel contaminants - perspective for monitoring hydrocarbon contamination: A review

    CSIR Research Space (South Africa)

    Maila, MP

    2005-01-01

    Full Text Available Moderately sensitive Kandeler et al. (1994) Batteries? of bioindicators Microbial bioluminescence, earthwormand seed germination Creosote, heavy, medium and light crude oils. Moderately sensitive. Earthworm4seed germination4 bioluminescence 25?17; 400 mggC01.... However, microbial bioluminescence, microbial biomass/counts and soil respiration have been evaluated as potential tools for monitoring of hydrocarbons (Delistraty, 1984; Kandeler et al., 1994; Steinberg et al., 1995; Van Beelen and Doelman, 1997; Phillips...

  12. Classification and modelling of non-extractable residue (NER) formation from xenobiotics in soil - a synthesis

    Science.gov (United States)

    Kaestner, Matthias; Nowak, Karolina; Miltner, Anja; Trapp, Stefan; Schaeffer, Andreas

    2014-05-01

    This presentation provides a comprehensive overview about the formation of non-extractable residues (NER) from organic pesticides and contaminants in soil and tries classifying the different types. Anthropogenic organic chemicals are deliberately (e.g. pesticides) or unintentionally (e.g. polyaromatic hydrocarbons [PAH], chlorinated solvents, pharmaceuticals) released in major amounts to nearly all compartments of the environment. Soils and sediments as complex matrices provide a wide variety of binding sites and are the major sinks for these compounds. Many of the xenobiotics entering soil undergo turnover processes and can be volatilised, leached to the groundwater, degraded by microorganisms or taken up and enriched by living organisms. Xenobiotic NER may be derived from parent compounds and primary metabolites that are sequestered (sorbed or entrapped) within the soil organic matter (type I NER) or can be covalently bound (type II NER). Especially type I NER may pose a considerably environmental risk of potential release. However, NER resulting from productive biodegradation, which means the conversion of carbon (or nitrogen) from the compounds into microbial biomass molecules during microbial degradation (type III, bioNER), do not pose any risk. Experimental and analytical approaches to clearly distinguish between the types are provided and a model to prospectively estimate their fate in soil is proposed.

  13. Predicting bioremediation of hydrocarbons: laboratory to field scale.

    Science.gov (United States)

    Diplock, E E; Mardlin, D P; Killham, K S; Paton, G I

    2009-06-01

    There are strong drivers to increasingly adopt bioremediation as an effective technique for risk reduction of hydrocarbon impacted soils. Researchers often rely solely on chemical data to assess bioremediation efficiently, without making use of the numerous biological techniques for assessing microbial performance. Where used, laboratory experiments must be effectively extrapolated to the field scale. The aim of this research was to test laboratory derived data and move to the field scale. In this research, the remediation of over thirty hydrocarbon sites was studied in the laboratory using a range of analytical techniques. At elevated concentrations, the rate of degradation was best described by respiration and the total hydrocarbon concentration in soil. The number of bacterial degraders and heterotrophs as well as quantification of the bioavailable fraction allowed an estimation of how bioremediation would progress. The response of microbial biosensors proved a useful predictor of bioremediation in the absence of other microbial data. Field-scale trials on average took three times as long to reach the same endpoint as the laboratory trial. It is essential that practitioners justify the nature and frequency of sampling when managing remediation projects and estimations can be made using laboratory derived data. The value of bioremediation will be realised when those that practice the technology can offer transparent lines of evidence to explain their decisions.

  14. Degradation of hydrocarbons under methanogenic conditions in different geosystems

    Science.gov (United States)

    Straaten, Nontje; Jiménez García, Núria; Richnow, Hans-Hermann; Krueger, Martin

    2014-05-01

    With increasing energy demand the search for new resources is becoming increasingly important for the future energy supply. Therefore the knowledge about fossil fuels like oil or natural gas and their extraction should be expanded. Biodegraded oil is found in many reservoirs worldwide. Consequently, it is very important to get insight in the microbial communities and metabolic processes involved in hydrocarbon degradation. Due to the lack of alternative electron acceptors in hydrocarbon-rich geosystems, degradation often takes place under methanogenic conditions. The aim of the present study is to identify the microorganisms and mechanisms involved in the degradation of complex hydrocarbons, like BTEX and polycyclic aromatic hydrocarbons, using culture dependent and independent techniques. For this purpose enrichment cultures from marine sediments, shales, coal and oil reservoirs are monitored for their capability to degrade alkanes and aromatic compounds. Moreover the environmental samples of these different geosystems analysed for evidence for the in situ occurrence of methanogenic oil degradation. The gas geochemical data provided in several cases hints for a recent biological origin of the methane present. First results of the microbial community analysis showed in environmental samples and enrichment cultures the existence of Bacteria known to degrade hydrocarbons. Also a diverse community of methanogenic Archaea could be found in the clone libraries. Additionally, in oil and coal reservoir samples the degradation of model hydrocarbons, e.g. methylnaphthalene, hexadecane and BTEX, to CH4 was confirmed by 13C-labeling. To explore the mechanisms involved in biodegradation, the enrichments as well as the original environmental samples are further analysed for the presence of respective functional genes.

  15. Apparatus and methods for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2016-04-26

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  16. Optrode for sensing hydrocarbons

    Science.gov (United States)

    Miller, Holly; Milanovich, Fred P.; Hirschfeld, Tomas B.; Miller, Fred S.

    1987-01-01

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons.

  17. Community Structure in Methanogenic Enrichments Provides Insight into Syntrophic Interactions in Hydrocarbon-Impacted Environments.

    Science.gov (United States)

    Fowler, S Jane; Toth, Courtney R A; Gieg, Lisa M

    2016-01-01

    The methanogenic biodegradation of crude oil involves the conversion of hydrocarbons to methanogenic substrates by syntrophic bacteria and subsequent methane production by methanogens. Assessing the metabolic roles played by various microbial species in syntrophic communities remains a challenge, but such information has important implications for bioremediation and microbial enhanced energy recovery technologies. Many factors such as changing environmental conditions or substrate variations can influence the composition and biodegradation capabilities of syntrophic microbial communities in hydrocarbon-impacted environments. In this study, a methanogenic crude oil-degrading enrichment culture was successively transferred onto the single long chain fatty acids palmitate or stearate followed by their parent alkanes, hexadecane or octadecane, respectively, in order to assess the impact of different substrates on microbial community composition and retention of hydrocarbon biodegradation genes. 16S rRNA gene sequencing showed that a reduction in substrate diversity resulted in a corresponding loss of microbial diversity, but that hydrocarbon biodegradation genes (such as assA/masD encoding alkylsuccinate synthase) could be retained within a community even in the absence of hydrocarbon substrates. Despite substrate-related diversity changes, all communities were dominated by hydrogenotrophic and acetotrophic methanogens along with bacteria including Clostridium sp., members of the Deltaproteobacteria, and a number of other phyla. Microbial co-occurrence network analysis revealed a dense network of interactions amongst syntrophic bacteria and methanogens that were maintained despite changes in the substrates for methanogenesis. Our results reveal the effect of substrate diversity loss on microbial community diversity, indicate that many syntrophic interactions are stable over time despite changes in substrate pressure, and show that syntrophic interactions amongst

  18. Community structure in methanogenic enrichments provides insight into syntrophic interactions in hydrocarbon-impacted environments

    Directory of Open Access Journals (Sweden)

    S. Jane eFowler

    2016-04-01

    Full Text Available The methanogenic biodegradation of crude oil involves the conversion of hydrocarbons to methanogenic substrates by syntrophic bacteria and subsequent methane production by methanogens. Assessing the metabolic roles played by various microbial species in syntrophic communities remains a challenge, but such information has important implications for bioremediation and microbial enhanced energy recovery technologies. Many factors such as changing environmental conditions or substrate variations can influence the composition and biodegradation capabilities of syntrophic microbial communities in hydrocarbon-impacted environments. In this study, a methanogenic crude oil-degrading enrichment culture was successively transferred onto the single long chain fatty acids palmitate or stearate followed by their parent alkanes, hexadecane or octadecane, respectively, in order to assess the impact of different substrates on microbial community composition and retention of hydrocarbon biodegradation genes. 16S rRNA gene sequencing showed that a reduction in substrate diversity resulted in a corresponding loss of microbial diversity, but that hydrocarbon biodegradation genes (such as assA/masD encoding alkylsuccinate synthase could be retained within a community even in the absence of hydrocarbon substrates. Despite substrate-related diversity changes, all communities were dominated by hydrogenotrophic and acetotrophic methanogens along with bacteria including Clostridium sp., members of the Deltaproteobacteria, and a number of other phyla. Microbial co-occurrence network analysis revealed a dense network of interactions amongst syntrophic bacteria and methanogens that were maintained despite changes in the substrates for methanogenesis. Our results reveal the effect of substrate diversity loss on microbial community diversity, indicate that many syntrophic interactions are stable over time despite changes in substrate pressure, and show that syntrophic

  19. Mantle hydrocarbons: abiotic or biotic?

    Science.gov (United States)

    Sugisaki, R; Mimura, K

    1994-06-01

    Analyses of 227 rocks from fifty localities throughout the world showed that mantle derived rocks such as tectonized peridotites in ophiolite sequences (tectonites) arid peridotite xenoliths in alkali basalts contain heavier hydrocarbons (n-alkanes), whereas igneous rocks produced by magmas such as gabbro arid granite lack them. The occurrence of hydrocarbons indicates that they were not derived either from laboratory contamination or from held contamination; these compounds found in the mantle-derived rocks are called here "mantle hydrocarbons." The existence of hydrocarbons correlates with petrogenesis. For example, peridotite cumulates produced by magmatic differentiation lack hydrocarbons whereas peridotite xenoliths derived from the mantle contain them. Gas chromatographic-mass spectrometric records of the mantle hydrocarbons resemble those of aliphatics in meteorites and in petroleum. Features of the hydrocarbons are that (a) the mantle hydrocarbons reside mainly along grain boundaries and in fluid inclusions of minerals; (b) heavier isoprenoids such as pristane and phytane are present; and (c) delta 13C of the mantle hydrocarbons is uniform (about -27%). Possible origins for the mantle hydrocarbons are as follows. (1) They were in organically synthesized by Fischer-Tropsch type reaction in the mantle. (2) They were delivered by meteorites and comets to the early Earth. (3) They were recycled by subduction. The mantle hydrocarbons in the cases of (1) and (2) are abiogenic and those in (3) are mainly biogenic. It appears that hydrocarbons may survive high pressures and temperatures in the mantle, but they are decomposed into lighter hydrocarbon gases such as CH4 at lower pressures when magmas intrude into the crust; consequently, peridotite cumulates do not contain heavier hydrocarbons but possess hydrocarbon gases up to C4H10.

  20. Bacterial sources for phenylalkane hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.; Winans, R.E. [Argonne National Lab., IL (United States); Langworthy, T. [Univ. of South Dakota, Vermillion, SD (United States)

    1996-10-01

    The presence of phenylalkane hydrocarbons in geochemical samples has been the source of much controversy. Although an anthropogenic input from detergent sources always appears likely, the distribution of phenylalkane hydrocarbons in some cases far exceeding that attributed to detergent input has led to a reappraisal of this view. Indeed, recent work involving analysis of the lipid hydrocarbon extracts from extant Thermoplasma bacteria has revealed the presence of phenylalkane hydrocarbons. The presence of phenylalkane hydrocarbons in sedimentary organic matter may therefore represent potential biological markers for thermophilic bacteria.

  1. A Review on the Genetics of Aliphatic and Aromatic Hydrocarbon Degradation.

    Science.gov (United States)

    Abbasian, Firouz; Lockington, Robin; Megharaj, Mallavarapu; Naidu, Ravi

    2016-01-01

    Because of the high diversity of hydrocarbons, degradation of each class of these compounds is activated by a specific enzyme. However, most of other downstream enzymes necessary for complete degradation of hydrocarbons maybe common between different hydrocarbons. The genes encoding proteins for degradation of hydrocarbons, including the proteins required for the uptake of these molecules, the specific enzyme used for the initial activation of the molecules and other necessary degrading enzymes are usually arranged as an operon. Although the corresponding genes in many phylogenetic groups of microbial species show different levels of diversity in terms of the gene sequence, the organisation of the genes in the genome or on plasmids and the activation mode (inductive or constitutive), some organisms show identical hydrocarbon-degrading genes, probably as a result of horizontal gene transfer between microorganisms.

  2. Microbial xanthophylls.

    Science.gov (United States)

    Bhosale, Prakash; Bernstein, Paul S

    2005-09-01

    Xanthophylls are oxygenated carotenoids abundant in the human food supply. Lutein, zeaxanthin, and cryptoxanthin are major xanthophyll carotenoids in human plasma. The consumption of these xanthophylls is directly associated with reduction in the risk of cancers, cardiovascular disease, age-related macular degeneration, and cataract formation. Canthaxanthin and astaxanthin also have considerable importance in aquaculture for salmonid and crustacean pigmentation, and are of commercial interest for the pharmaceutical and food industries. Chemical synthesis is a major source for the heavy demand of xanthophylls in the consumer market; however, microbial producers also have potential as commercial sources. In this review, we discuss the biosynthesis, commercial utility, and major microbial sources of xanthophylls. We also present a critical review of current research and technologies involved in promoting microbes as potential commercial sources for mass production.

  3. 控释肥膜壳对土壤酶活性及微生物量碳氮磷的影响%Effects of Controlled-Release Fertilizer Residual Coating on Enzyme and Microbial Biomass Carbon Nitrogen Phosphorus

    Institute of Scientific and Technical Information of China (English)

    孔静; 刘双; 徐林林; 董元杰; 王艳华

    2012-01-01

    选用硫膜和树脂膜两种肥料膜壳,每种设置3个浓度梯度,研究了控释肥膜壳对土壤酶活性及微生物量碳氮磷的影响。结果表明,施用硫膜和树脂膜一定程度上对土壤生物学性质产生了影响。膜壳对土壤酶活性的影响主要表现在对脲酶和过氧化氢酶活性上,而对土壤磷酸酶活性影响不大。成熟期施用硫膜和树脂膜处理显著提高了土壤脲酶活性,这与结荚期有所不同,说明硫膜能提高花生成熟期土壤脲酶活性。树脂膜和硫膜处理均以中等量(2g/kg)处理时微生物量碳和氮含量最大,施用控释肥残膜处理显著降低了微生物量磷含量。%Sulfur film and resin film were used in this study, and each membrane shell was set by three concent.ration gradients. We studied the effects of the membrane shell on soil enzyme activities and microbial biomass carbon nitrogen and phosphorus. The results showed that application of sulfur film and resin film caused a certain extent effect on soil biological properties and the membrane shell caused a significantly effect on the urease and catalase activities, and little effect on soil phosphatase activity. At maturity stage, the sulfur mem- brane treatments significantly increased soil urease activity, which was different from the podding stage. was biggest of microbial biomass carbon and nitrogen content when the aoplication rate was moderate There (2g/kg). In addition, application of sulfur film and resin film significantly reduced the microbial biomass phosphorus content.

  4. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  5. Characterization of Residual Medium Peptides from Yersinia pestis Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Clowers, Brian H.; Wunschel, David S.; Kreuzer, Helen W.; Engelmann, Heather E.; Valentine, Nancy B.; Wahl, Karen L.

    2013-04-03

    Using a range of common microbial medium formulations (TSB, BHI, LB, and G-media), two attenuated strains of Y. pestis (KIM D27 (pgm-) and KIMD1 lcr-) were cultivated in triplicate. These cellular suspensions were used to develop a method of extracting residual medium peptides from the final microbial preparation to assess their relative abundance and identity. Across the conditions examined, which included additional cellular washing and different forms of microbial inactivation, residual medium peptides were detected. Despite the range of growth medium sources used and the associated manufacturing processes used in their production, a high degree of peptide similarity was observed for a given medium recipe. These results demonstrate that residual medium peptides are retained using traditional microbial cultivation techniques and may be used to inform forensic investigations with respect to production deduction.

  6. Water system microbial check valve development

    Science.gov (United States)

    Colombo, G. V.; Greenley, D. R.; Putnam, D. F.

    1978-01-01

    A residual iodine microbial check valve (RIMCV) assembly was developed and tested. The assembly is designed to be used in the space shuttle potable water system. The RIMCV is based on an anion exchange resin that is supersaturated with an iodine solution. This system causes a residual to be present in the effluent water which provides continuing bactericidal action. A flight prototype design was finalized and five units were manufactured and delivered.

  7. Numerical modelling on fate and transport of petroleum hydrocarbons in an unsaturated subsurface system for varying source scenario

    Indian Academy of Sciences (India)

    M Berlin; M Vasudevan; G Suresh Kumar; Indumathi M Nambi

    2015-04-01

    The vertical transport of petroleum hydrocarbons from a surface spill through an unsaturated subsurface system is of major concern in assessing the vulnerability of groundwater contamination. A realistic representation on fate and transport of volatile organic compounds at different periods after spill is quite challenging due to the variation in the source behaviour at the surface of spill as well as the variation in the hydrodynamic parameters and the associated inter-phase partitioning coefficients within the subsurface. In the present study, a one dimensional numerical model is developed to simulate the transport of benzene in an unsaturated subsurface system considering the effect of volatilization, dissolution, adsorption and microbial degradation of benzene for (i) constant continuous source, (ii) continuous decaying source, and (iii) residual source. The numerical results suggest that volatilization is the important sink for contaminant removal considering the soil air migration within the unsaturated zone. It is also observed that the coupled effect of dissolution and volatilization is important for the decaying source at the surface immediately after the spill, whereas rate-limited dissolution from residually entrapped source is responsible for the extended contamination towards later period.

  8. Determining the metabolic footprints of hydrocarbon degradation using multivariate analysis.

    Science.gov (United States)

    Smith, Renee J; Jeffries, Thomas C; Adetutu, Eric M; Fairweather, Peter G; Mitchell, James G

    2013-01-01

    The functional dynamics of microbial communities are largely responsible for the clean-up of hydrocarbons in the environment. However, knowledge of the distinguishing functional genes, known as the metabolic footprint, present in hydrocarbon-impacted sites is still scarcely understood. Here, we conducted several multivariate analyses to characterise the metabolic footprints present in a variety of hydrocarbon-impacted and non-impacted sediments. Non-metric multi-dimensional scaling (NMDS) and canonical analysis of principal coordinates (CAP) showed a clear distinction between the two groups. A high relative abundance of genes associated with cofactors, virulence, phages and fatty acids were present in the non-impacted sediments, accounting for 45.7% of the overall dissimilarity. In the hydrocarbon-impacted sites, a high relative abundance of genes associated with iron acquisition and metabolism, dormancy and sporulation, motility, metabolism of aromatic compounds and cell signalling were observed, accounting for 22.3% of the overall dissimilarity. These results suggest a major shift in functionality has occurred with pathways essential to the degradation of hydrocarbons becoming overrepresented at the expense of other, less essential metabolisms.

  9. Determining the metabolic footprints of hydrocarbon degradation using multivariate analysis.

    Directory of Open Access Journals (Sweden)

    Renee J Smith

    Full Text Available The functional dynamics of microbial communities are largely responsible for the clean-up of hydrocarbons in the environment. However, knowledge of the distinguishing functional genes, known as the metabolic footprint, present in hydrocarbon-impacted sites is still scarcely understood. Here, we conducted several multivariate analyses to characterise the metabolic footprints present in a variety of hydrocarbon-impacted and non-impacted sediments. Non-metric multi-dimensional scaling (NMDS and canonical analysis of principal coordinates (CAP showed a clear distinction between the two groups. A high relative abundance of genes associated with cofactors, virulence, phages and fatty acids were present in the non-impacted sediments, accounting for 45.7% of the overall dissimilarity. In the hydrocarbon-impacted sites, a high relative abundance of genes associated with iron acquisition and metabolism, dormancy and sporulation, motility, metabolism of aromatic compounds and cell signalling were observed, accounting for 22.3% of the overall dissimilarity. These results suggest a major shift in functionality has occurred with pathways essential to the degradation of hydrocarbons becoming overrepresented at the expense of other, less essential metabolisms.

  10. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    Science.gov (United States)

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  11. Uranium Recovery from Uranium Mineral Bio-Heap Residues with Microbial Column Leaching Process%微生物柱浸法从铀矿石堆浸尾渣中回收铀的研究

    Institute of Scientific and Technical Information of China (English)

    李江; 刘亚洁; 车江华; 饶军

    2012-01-01

    Column bio-leaching tests under different spraying conditions on the uranium mineral bio-heap residues were conducted with bio-heap leaching process. The uranium content of the residues was 0. 014%. The results show that the leaching rate is 50% after a leaching period of four months with ratio of liquid to solid of L 74 and one spray for two-days, while the leaching rate is 28- 6% with ratio of liquid to solid of 0. 94 and one spray for four-days. This leaching process with small and interval spray has the advantages of low cost, efficient uranium recovery from the bio-heap residues and less environmental pollution.%对广东某铀矿微生物堆浸后品位为0.014%的尾渣进行了不同喷淋条件下的微生物柱浸试验.结果表明,浸出周期4个月,在2天喷淋1次条件下,液固比为1.74,渣计浸出率50%;在4天喷淋1次条件下,液固比为0.94,渣计浸出率28.6%.小喷淋量、间歇式喷淋的微生物浸出工艺,成本低,能有效回收堆浸尾渣中的铀资源,同时减少环境污染.

  12. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice; Kulkarni, Sudhir S.; Funk, Edward W.

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  13. Application of geo-microbial prospecting method for finding oil and gas reservoirs

    Science.gov (United States)

    Rasheed, M. A.; Hasan, Syed Zaheer; Rao, P. L. Srinivasa; Boruah, Annapurna; Sudarshan, V.; Kumar, B.; Harinarayana, T.

    2015-03-01

    Microbial prospecting of hydrocarbons is based on the detection of anomalous population of hydrocarbon oxidizing bacteria in the surface soils, indicates the presence of subsurface oil and gas accumulation. The technique is based on the seepage of light hydrocarbon gases such as C1-C4 from the oil and gas pools to the shallow surface that provide the suitable conditions for the development of highly specialized bacterial population. These bacteria utilize hydrocarbon gases as their only food source and are found enriched in the near surface soils above the hydrocarbon bearing structures. The methodology involves the collection of soil samples from the survey area, packing, preservation and storage of samples in pre-sterilized sample bags under aseptic and cold conditions till analysis and isolation and enumeration of hydrocarbon utilizing bacteria such as methane, ethane, propane, and butane oxidizers. The contour maps for the population density of hydrocarbon oxidizing bacteria are drawn and the data can be integrated with geological, geochemical, geophysical methods to evaluate the hydrocarbon prospect of an area and to prioritize the drilling locations thereby reducing the drilling risks and achieve higher success in petroleum exploration. Microbial Prospecting for Oil and Gas (MPOG) method success rate has been reported to be 90%. The paper presents details of microbial prospecting for oil and gas studies, excellent methodology, future development trends, scope, results of study area, case studies and advantages.

  14. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  15. Metagenomic approach for understanding microbial population from petroleum muck.

    Science.gov (United States)

    Joshi, M N; Dhebar, S V; Dhebar, S V; Bhargava, P; Pandit, A S; Patel, R P; Saxena, A K; Bagatharia, S B

    2014-05-29

    Petroleum products play a major role in fueling the economy of the world but the pollution they create has become a critical issue. Understanding the diversity present in pipeline muck will help with the exploration of new microbial strains with better hydrocarbon degrading capacities for bioremediation of polluted sites. This study provides an analysis of petroleum muck using next generation sequencing.

  16. Metagenomic Approach for Understanding Microbial Population from Petroleum Muck

    OpenAIRE

    Joshi, M. N.; Dhebar, S. V.; Bhargava, P.; Pandit, A. S.; Patel, R. P.; A K Saxena; Bagatharia, S. B.

    2014-01-01

    Petroleum products play a major role in fueling the economy of the world but the pollution they create has become a critical issue. Understanding the diversity present in pipeline muck will help with the exploration of new microbial strains with better hydrocarbon degrading capacities for bioremediation of polluted sites. This study provides an analysis of petroleum muck using next generation sequencing.

  17. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    Energy Technology Data Exchange (ETDEWEB)

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  18. Recalcitrance of polycyclic aromatic hydrocarbons in soil contributes to background pollution

    Energy Technology Data Exchange (ETDEWEB)

    Posada-Baquero, Rosa [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain); Ortega-Calvo, Jose-Julio, E-mail: jjortega@irnase.csic.es [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), C.S.I.C., Apartado 1052, E-41080 Seville (Spain)

    2011-12-15

    The microbial accessibility of native phenanthrene and pyrene was determined in soils representing background scenarios for pollution by polycyclic aromatic hydrocarbons (PAHs). The soils were selected to cover a wide range of concentrations of organic matter (1.7-10.0%) and total PAHs (85-952 {mu}g/kg). The experiments included radiorespirometry determinations of biodegradation with {sup 14}C-labeled phenanthrene and pyrene and chemical analyses to determine the residual concentrations of the native compounds. Part of the tests relied on the spontaneous biodegradation of the chemicals by native microorganisms; another part also involved inoculation with PAH-degrading bacteria. The results showed the recalcitrance of PAHs already present in the soils. Even after extensive mineralization of the added {sup 14}C-PAHs, the concentrations of native phenanthrene and pyrene did not significantly decrease. We suggest that aging processes operating at background concentrations may contribute to recalcitrance and, therefore, to ubiquitous pollution by PAHs in soils. - Highlights: > Background PAHs in soils are highly resistant to biodegradation. > Recalcitrance occurs even after inoculation with specialized microorganisms. > Recalcitrance is caused by a low bioaccessibility and aging. > Time (aging) seems a relevant factor causing recalcitrance. > Recalcitrance can explain ubiquitous PAH background pollution. - Background soil PAHs are highly resistant to biodegradation.

  19. Temporal biogeophysical signatures at hydrocarbon contaminated sites associated with long-term remediation efforts

    Science.gov (United States)

    Atekwana, E.; Che-Alota, V.; Atekwana, E.; Werkema, D. D.

    2009-05-01

    Biogeophysical signatures of hydrocarbon contaminated sites provide ideal laboratories for investigating microbial-geophysical relationships as the excess organic carbon present at these sites stimulates microbial activity. As such geophysical investigations have documented characteristic changes associated with hydrocarbon biodegradation in both field and laboratory experiments. The conceptual model that results from almost a decade of studies from these environments is one in which over time, the geophysical signatures due to bio-physicochemical changes imparted on the aquifer by the microbial activity reach some maximum or minimum related to the availability of terminal electron acceptors, the organic carbon source concentration, and microbial activity. However, with continuous removal of the contaminant mass either by natural attenuation (e.g., intrinsic bioremediation) or engineered (bio) remediation, a decrease in the microbial activity is predicted to cause associated changes in the geophysical properties (i.e., geophysical signatures revert to original conditions). This paper will present the results of repeated geophysical investigations at a hydrocarbon contaminated site acquired over an eleven-year period documenting changes in geophysical signatures associated with removal of hydrocarbon mass in the contaminated zone. Initial investigations at the site showed that relative to background, the contaminated area was characterized by higher bulk electrical conductivity, positive SP anomaly, and attenuated GPR reflections. Over time, the contaminated zone bulk electrical conductivity had reverted to near background conditions, the positive SP anomaly became more negative, and the zone of attenuated GPR reflections showed increased signal strength. The removal of hydrocarbon mass in the vadose zone over the plume by a soil vapor extraction system decreased the level of biological activity and therefore the magnitude of the geophysical signatures. We conclude

  20. Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.

    2006-07-01

    Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full

  1. Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

    Science.gov (United States)

    Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

    2012-11-01

    Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon

  2. Microbial Metalloproteomics

    Directory of Open Access Journals (Sweden)

    Peter-Leon Hagedoorn

    2015-12-01

    Full Text Available Metalloproteomics is a rapidly developing field of science that involves the comprehensive analysis of all metal-containing or metal-binding proteins in a biological sample. The purpose of this review is to offer a comprehensive overview of the research involving approaches that can be categorized as inductively coupled plasma (ICP-MS based methods, X-ray absorption/fluorescence, radionuclide based methods and bioinformatics. Important discoveries in microbial proteomics will be reviewed, as well as the outlook to new emerging approaches and research areas.

  3. Microbial Ecosystems, Protection of

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Conservation of microbial diversity and ecosystem functions provided by microbes; Preservation of microbial diversity and ecosystem functions provided by microbes Definition The use, management, and conservation of ecosystems in order to preserve microbial diversity and functioning.

  4. Microbial Ecosystems, Protection of

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Conservation of microbial diversity and ecosystem functions provided by microbes; Preservation of microbial diversity and ecosystem functions provided by microbes Definition The use, management, and conservation of ecosystems in order to preserve microbial diversity and functioning. Introdu

  5. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    Science.gov (United States)

    Abbas, M.; Jardani, A.

    2015-12-01

    The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

  6. 微生物法降解药渣中残留四环素的试验研究%Experimental Study on Microbial Degradation of Tetracycline Residues in Antibiotic Waste

    Institute of Scientific and Technical Information of China (English)

    马志强; 马玉龙; 谢丽; 张作义; 王敏

    2012-01-01

    发酵法生产四环素过程中会产出大最废弃药渣,其中含有丰富的营养物质,但同时也残留一定量未提取完的四环素,从而限制其资源化利用.研究筛选到一株对药渣中残留四环具有高效降解作用的优势菌株,经16S rDNA鉴定为无丙二酸柠檬酸杆菌(Citrobacter amalonaticus).该菌株在35℃、初始pH 5.5、装液量为50mL、接种量为5%、转速为150 r/min条件下,处理四环素药渣72h,药渣中残留四环素的降解率为86.1%.%Tetracycline production by means of fermentation generated masses of pharmaceutical solid waste which though contains rich nutrition can not be reclaimed and utilized due to the tetracycline residues it contains. In this paper, a tetracycline-degrading strain was isolated and identified by 16S rDNA as Citrobacter amalonaticus, and the degradation experiment results indicated that the antibiotic waste containing residual tetracycline was treated with C. amalonaticus for 108 h under the conditions of temperature 35 ℃, pH value 5.5, liquid volume 50 mL, incubation amount 5% and rotation speed 150 r/min.

  7. From Rare to Dominant: a Fine-Tuned Soil Bacterial Bloom during Petroleum Hydrocarbon Bioremediation.

    Science.gov (United States)

    Fuentes, Sebastián; Barra, Bárbara; Caporaso, J Gregory; Seeger, Michael

    2015-11-20

    Hydrocarbons are worldwide-distributed pollutants that disturb various ecosystems. The aim of this study was to characterize the short-lapse dynamics of soil microbial communities in response to hydrocarbon pollution and different bioremediation treatments. Replicate diesel-spiked soil microcosms were inoculated with either a defined bacterial consortium or a hydrocarbonoclastic bacterial enrichment and incubated for 12 weeks. The microbial community dynamics was followed weekly in microcosms using Illumina 16S rRNA gene sequencing. Both the bacterial consortium and enrichment enhanced hydrocarbon degradation in diesel-polluted soils. A pronounced and rapid bloom of a native gammaproteobacterium was observed in all diesel-polluted soils. A unique operational taxonomic unit (OTU) related to the Alkanindiges genus represented ∼ 0.1% of the sequences in the original community but surprisingly reached >60% after 6 weeks. Despite this Alkanindiges-related bloom, inoculated strains were maintained in the community and may explain the differences in hydrocarbon degradation. This study shows the detailed dynamics of a soil bacterial bloom in response to hydrocarbon pollution, resembling microbial blooms observed in marine environments. Rare community members presumably act as a reservoir of ecological functions in high-diversity environments, such as soils. This rare-to-dominant bacterial shift illustrates the potential role of a rare biosphere facing drastic environmental disturbances. Additionally, it supports the concept of "conditionally rare taxa," in which rareness is a temporary state conditioned by environmental constraints.

  8. Biological Activity Assessment in Mexican Tropical Soils with Different Hydrocarbon Contamination Histories

    OpenAIRE

    Riveroll-Larios, Jessica; Escalante-Espinosa, Erika; Fócil-Monterrubio, Reyna L.; Díaz-Ramírez, Ildefonso J.

    2015-01-01

    The use of soil health indicators linked to microbial activities, such as key enzymes and respirometric profiles, helps assess the natural attenuation potential of soils contaminated with hydrocarbons. In this study, the intrinsic physicochemical characteristics, biological activity and biodegradation potential were recorded for two soils with different contamination histories (>5 years and

  9. Removal of crude oil polycyclic aromatic hydrocarbons via organoclay-microbe-oil interactions.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Fialips, Claire I

    2017-05-01

    Clay minerals are quite vital in biogeochemical processes but the effect of organo-clays in the microbial degradation of crude oil polycyclic aromatic hydrocarbons is not well understood. The role of organo-saponite and organo-montmorillonite in comparison with the unmodified clays in crude oil polycyclic aromatic hydrocarbons (PAHs) removal via adsorption and biodegradation was studied by carrying out microcosm experiments in aqueous clay/oil systems with a hydrocarbon degrading microbial community that is predominantly alcanivorax spp. Montmorillonite and saponite samples were treated with didecyldimethylammonium bromide to produce organo-montmorillonite and organo-saponite used in this study. Obtained results indicate that clays with high cation exchange capacity (CEC) such as montmorillonite produced organo-clay (organomontmorillonite) that was not stimulatory to biodegradation of crude oil polycyclic aromatic compounds, especially the low molecular weight (LMW) ones, such as dimethylnaphthalenes. It is suggested that interaction between the organic phase of the organo-clay and the crude oil PAHs which is hydrophobic in nature must have reduced the availability of the polycyclic aromatic hydrocarbons for biodegradation. Organo-saponite did not enhance the microbial degradation of dimethylnaphthalenes but enhanced the biodegradation of some other PAHs such as phenanthrene. The unmodified montmorillonite enhanced the microbial degradation of the PAHs and is most likely to have done so as a result of its high surface area that allows the accumulation of microbes and nutrients enhancing their contact.

  10. Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone

    Science.gov (United States)

    Lahvis, Matthew A.; Baehr, Arthur L.

    1996-07-01

    The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 gyr-1 (11.7 gal. yr-1) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 gm-2yr-1 (1.45×10-3 and 1.51×10-3 gal.ft.-2yr-1) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization.

  11. Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone

    Science.gov (United States)

    Lahvis, M.A.; Baehr, A.L.

    1996-01-01

    The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 g yr-1 (11.7 gal. yr-1) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 g m-2 yr-1 (1.45 x 10-3 and 1.51 x 10-3 gal. ft.-2 yr-1) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization.

  12. Construction of a Microbial Consortium RXS with High Degradation Ability for Cassava Residues and Studies on Its Fermentative Characteristics%高效木薯渣分解复合菌群RXS的构建及其发酵特性研究

    Institute of Scientific and Technical Information of China (English)

    何江; 毛忠贵; 张庆华; 张建华; 唐蕾; 张宏建

    2012-01-01

    A microbial consortium with high effective and stable cellulosic degradation ability was constructed by successive enrichment and incubation in a peptone cellulose medium using cassava residues and filter paper as carbon sources,where the inoculums were sampled from the environment filled with rotten lignocellulosic materials.The degradation ability to different cellulosic materials and change of main parameters during the degradation process of cassava residues by this consortium was investigated in this study.It was found that,this consortium can efficiently degrade filter paper,absorbent cotton,avicael,wheat-straw and cassava residues.During the degradation process of cassava residues,the key hydrolytic enzymes including cellulase,hemicellulase and pectinase showed a maximum enzyme activity of 34.4,90.5 and 15.8 U on the second or third day,respectively.After 10 days' fermentation,the degradation ratio of cellulose,hemicellulose and lignin of cassava residues was 79.8%,85.9% and 19.4% respectively,meanwhile the loss ratio of cassava residues reached 61.5%.Otherwise,it was found that the dominant metabolites are acetic acid,butyric acid,caproic acid and glycerol,and the highest hydrolysis ratio is obtained on the second day by monitoring SCOD,total volatile fatty acids and total sugars.The above results revealed that this consortium can effectively hydrolyze cassava residues(the waste produced during the cassava based bioethanol production) and has great potential to be utilized for the pretreatment of cassava residues for biogas fermentation%从富含腐烂纤维质的环境中取样,通过以木薯渣及滤纸为碳源的蛋白胨纤维素培养基不断地富集培养,构建了一组高效稳定的纤维质分解复合菌群.考察了该复合菌群对不同纤维质底物的分解性能及其在木薯渣水解过程中主要参数的变化.研究发现该复合菌群对滤纸、脱脂棉、微晶纤维素、麦秸秆和木薯渣等原料均能够进行

  13. Bioavailability enhanced rhizosphere remediation of petroleum hydrocarbon contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Marchenko, A.; Vorobyov, A.; Zharikov, G.; Ermolenko, Z.; Dyadishchev, N.; Borovick, R.; Sokolov, M. [Research Centre for Toxicology and Hygienic Regulation of Biopreparations, Moscow region (Russian Federation); Ortega-Calvo, J.J. [Instituto de Recursos Naturales y Agrobiologia, CSIC, Sevilla (Spain)

    2005-07-01

    Aliphatic, aromatic and polycyclic aromatic oil hydrocarbons are structurally complicated man-caused pollutants that are constantly brought into biosphere. Oil production in Russia, so as all over the world, is connected with pollution of biotopes, ecosystems and agro-landscapes. Presently large funds are allocated either for oil leak prevention or for discharged oil gathering. At the same time, in spite of large necessity in technologies for efficient reconstruction of soil bio-productivity, reliable regional systems of their remediation in situ have not been developed yet. One such method is rhizosphere remediation, a biotechnology, based on the functioning of plant-microbial complexes. Little is known about bioavailability in phyto-remediation systems. Specific bioavailability-promoting mechanisms, operating in soil with hydrocarbon-degrading populations, may be responsible for increased rates of pollutant transformation (increased bacterial adherence to the pollutants, production of bio-surfactants by bacteria or by plants, possible role of chemotaxis). In the course of work collection of 42 chemo-tactically active bio-surfactant producing strain-degraders of petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) was created. Two representative strains were selected for detailed chemotaxis studies with PAHs (naphthalene, phenanthrene, anthracene, and pyrene), bacterial lipopolysaccharide and root exudates from seven different plants. These strains are produce the bio-surfactants (rhamno-lipid). The chemotactic response was quantified with a capillary and densitometric chemotaxis assay. Surface tension of cultural liquid was measured after cultivation of strains in the presence of hexadecane or phenanthrene with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. Total petroleum Hydrocarbons (TPH) in soil were analyzed by infra-red spectroscopy method. PAHs

  14. Metabolism of Benzene, Toluene, and Xylene Hydrocarbons in Soil†

    OpenAIRE

    Tsao, C.-W.; Song, H. -G.; Bartha, R

    1998-01-01

    Enrichment cultures obtained from soil exposed to benzene, toluene, and xylene (BTX) mineralized benzene and toluene but cometabolized only xylene isomers, forming polymeric residues. This observation prompted us to investigate the metabolism of 14C-labeled BTX hydrocarbons in soil, either individually or as mixtures. BTX-supplemented soil was incubated aerobically for up to 4 weeks in a sealed system that automatically replenished any O2 consumed. The decrease in solvent vapors and the produ...

  15. Biodegradation studies of oil sludge containing high hydrocarbons concentration

    Energy Technology Data Exchange (ETDEWEB)

    Olguin-Lora, P.; Munoz-Colunga, A.; Castorena-Cortes, G.; Roldan-Carrillo, T.; Quej Ake, L.; Reyes-Avila, J.; Zapata-Penasco, I.; Marin-Cruz, J.

    2009-07-01

    Oil industry has a significant impact on environment due to the emission of, dust, gases, waste water and solids generated during oil production all the way to basic petrochemical product manufacturing stages. the aim of this work was to evaluate the biodegradation of sludge containing high hydrocarbon concentration originated by a petroleum facility. A sludge sampling was done at the oil residuals pool (ORP) on a gas processing center. (Author)

  16. Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment

    Science.gov (United States)

    Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

    1998-01-01

    The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

  17. Biodegradation of aliphatic hydrocarbons in the presence of hydroxy cucurbit[6]uril.

    Science.gov (United States)

    Pasumarthi, Rajesh; Kumar, Vikash; Chandrasekharan, Sivaraman; Ganguly, Anasuya; Banerjee, Mainak; Mutnuri, Srikanth

    2014-11-15

    Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions.

  18. Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

    Science.gov (United States)

    Kallenbach, Cynthia M.; Frey, Serita D.; Grandy, A. Stuart

    2016-11-01

    Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that microbial residues account for the chemistry, stability and abundance of SOM is still lacking. Further, emerging models emphasize the stabilization of microbial-derived SOM by abiotic mechanisms, while the effects of microbial physiology on microbial residue production remain unclear. Here we provide the first direct evidence that soil microbes produce chemically diverse, stable SOM. We show that SOM accumulation is driven by distinct microbial communities more so than clay mineralogy, where microbial-derived SOM accumulation is greatest in soils with higher fungal abundances and more efficient microbial biomass production.

  19. Aliphatic hydrocarbons in sediment cores from the southern basin of Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Doskey, P.V. [Argonne National Lab., IL (United States). Environmental Research Division; Andren, A.W. [Univ. of Wisconsin, Madison, WI (United States). Water Chemistry Program

    1991-10-01

    Aliphatic hydrocarbons in sediments of the southern basin of Lake Michigan have planktonic, terrigenous, and petroleum residue origins. Surficial sediments collected near the eastern shore in 60-80 m of water contained more petroleum residue and planktonic hydrocarbons and exhibited less terrigenous character than sediments collected from the deepest location in the basin. Petroleum residue inputs have increased since 1900 as evidenced by a change in the flux of an unresolved complex mixture (UCM) of hydrocarbons from 6 ng/cm{sup 2}{center_dot}yr to a flux of approximately 100 ng/cm{sup 2}{center_dot}yr in 1980. Sediment profiles of the UCM exhibited subsurface concentration maxima that may be due to reduced inputs of combustion products or feeding by oligochaetes. Profiles of n-C{sub l7} and pristane indicated that planktonic n-alkanes undergo degradation in the aerobic, mixed zone of the sediments.

  20. Hydrocarbon conversion catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  1. Magnetic Susceptibility Measurements as a Proxy for Hydrocarbon Biodegradation

    Science.gov (United States)

    Mewafy, F.; Atekwana, E. A.; Slater, L. D.; Werkema, D.; Revil, A.; Ntarlagiannis, D.; Skold, M.

    2011-12-01

    Magnetic susceptibility (MS) measurements have been commonly used in paleoclimate studies, as a proxy for environmental pollution such as heavy metal contamination, and for delineating zones of oil seeps related to hydrocarbon exploration. Few studies have assessed the use of MS measurements for mapping zones of oil pollution. In this study, we investigated the variation in magnetic susceptibility across a hydrocarbon contaminated site undergoing biodegradation. Our objective was to investigate if MS measurements could be used as a proxy indicator of intrinsic bioremediation linked to the activity of iron reducing bacteria. An improved understanding of the mechanisms generating geophysical signatures associated with microbial enzymatic activity could permit the development of geophysical imaging technologies for long-term, minimally invasive and sustainable monitoring of natural biodegradation at oil spill sites. We used a Bartington MS probe to measure MS data along fifteen boreholes within contaminated (both free phase and dissolved phase hydrocarbon plumes) and clean areas. Our results show the following: (1) an enhanced zone of MS straddling the water table at the contaminated locations, not observed at the clean locations; (2) MS values within the free product plume are higher compared to values within the dissolved product plume; (3) the MS values within the vadoze zone above the free product plume are higher compared to values within the dissolved product plume; 4) the zone of high MS is thicker within the free product plume compared to the dissolved product plume. We suggest that the zone of enhanced MS results from the precipitation of magnetite related to the oxidation of the hydrocarbons coupled to iron reduction. Our data documents a strong correlation between MS and hydrocarbon concentration. We conclude that recognition of these zones of enhanced magnetite formation allows for the application of MS measurements as a: (1) low cost, rapid monitoring

  2. Anaerobic Microbial Transformation of Aromatic Hydrocarbons and Mixtures of Aromatic Hydrocarbons and Halogenated Solvents.

    Science.gov (United States)

    1992-08-25

    0.005 Pantothenic acid 0.005 p-Aminobenzoic ac id 0.005 (PABA) Cyanocobalamin (B1 2 ) 0.005 Thioctic (lipoic) acid 0.005 Coenzyme M (Mercapto...vitamin B12 ( cyanocobalamin ), and others -- had been reported to reductively dechlorinate CT in the presence of reducing 42 agents (Castro and Cray

  3. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  4. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    2013-01-01

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting protein

  5. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting

  6. Use of the Complex Conductivity Method to Monitor Hydrocarbon Degradation in Brackish Environments

    Science.gov (United States)

    Ntarlagiannis, D.; Beaver, C. L.; Kimak, C.; Slater, L. D.; Atekwana, E. A.; Rossbach, S.

    2015-12-01

    Hydrocarbon contamination of the subsurface is a global environmental problem. The size, location and recurrence rate of contamination very often inhibits active remediation strategies. When there is no direct threat to humans, and direct/invasive remediation methods are prohibited, monitored natural attenuation is often the remediation method of choice. Consequently, long-term monitoring of hydrocarbon degradation is needed to validate remediation. Geophysical methods, frequently utilized to characterize subsurface contamination, have the potential to be adopted for long term monitoring of contaminant degradation. Over the last decade, the complex conductivity method has shown promise as a method for monitoring hydrocarbon degradation processes in freshwater environments. We investigated the sensitivity of complex conductivity to natural attenuation of oil in a brackish setting, being more representative of the conditions where most oil spills occur such as in coastal environments. We performed a series of laboratory hydrocarbon biodegradation experiments whilst continuously monitoring complex conductivity. Sediments from a beach impacted by the Deepwater Horizon (DWH) spill were used to provide the hydrocarbon degraders, while fluids with three different salinities, ranging from fresh water to brackish water, were used as the supporting media. All experimental columns, including two abiotic controls, were run in duplicate. Early results show a dependence of the complex conductivity parameters (both electrolytic and interfacial) on biodegradation processes. Despite the small signals relative to freshwater conditions, the imaginary part of the complex conductivity appears to be sensitive to biodegradation processes. The columns with highest salinity fluids - similar to the salinites for the site where the sediments were collected - showed distinctive complex conductivity responses similar to microbial growth curves. Geochemical monitoring confirmed elevated rates

  7. Avaliação da qualidade nutricional da silagem de cana-de-açúcar com aditivos microbianos e enriquecida com resíduo da colheita de soja Evaluation of the nutritional quality of sugarcane silage treated with microbial additives and soybean crop residue

    Directory of Open Access Journals (Sweden)

    Acyr Wanderley de Paula Freitas

    2006-02-01

    Full Text Available Objetivou-se avaliar as características fermentativas e a qualidade nutricional da silagem de cana-de-açúcar tratada com aditivos microbianos e enriquecida com 10% de resíduo da colheita de soja, com base no peso verde da cana. O experimento foi conduzido em delineamento inteiramente ao acaso, com três repetições, utilizando-se a variedade RB855536, colhida em soca aos 16 meses. Embora a adição do resíduo da colheita de soja tenha promovido aumento do pH final da silagem, os tratamentos com resíduo diminuíram em 33% as perdas de matéria seca das silagens e em 60% o teor de N-amoniacal em relação ao nitrogênio total. A adição dos inoculantes reduziu o pH da silagem quando em associação ao resíduo de soja, não exercendo efeito significativo sobre os outros parâmetros estudados. Em todos os tratamentos, as silagens apresentaram maiores concentrações dos componentes da fibra e redução nos teores de MS em relação ao material original, antes da ensilagem. Nos tratamentos com resíduo, os valores de digestibilidade in vitro da matéria seca (DIVMS foram superiores aos obtidos nos demais tratamentos. Quando comparado o material utilizado para ensilagem, a redução na digestibilidade foi superior para os tratamentos sem o resíduo (24,3 vs 9,3%. A associação do resíduo da colheita de soja à cana-de-açúcar para ensilagem proporcionou melhor qualidade nutritiva, com menores perdas de MS e carboidratos solúveis, principalmente na forma de gases, e, conseqüentemente, menor acúmulo dos componentes da parede celular, além de redução na DIVMS da forragem. Não se recomenda a utilização dos inoculantes L. plantarum e L. buchneri na ensilagem da cana-de-açúcar, pois nenhuma melhoria foi observada na composição química ou no perfil de fermentação das silagens.The objective of this trial was to evaluate the fermentative characteristics and nutritional quality of sugarcane treated with microbial additives and 10% of

  8. Geochemical characterization of the hydrous pyrolysis products from a recent cyanobacteria-dominated microbial mat

    Energy Technology Data Exchange (ETDEWEB)

    Franco, N.; Mendoça-Filho, J.G.; Silva, T.F.; Stojanovic, K.; Fontana, L.F.; Carvalhal-Gomes, S.B.V.; Silva, F.S.; Furukawa, G.G.

    2016-07-01

    Hydrous pyrolysis experiments were performed on a recent microbial mat sample from Lagoa Vermelha, Brazil, to determine whether crude oil can be generated and expelled during artificial maturation of the Organic Matter (OM). The experiments were conducted at 280ºC, 330ºC and 350ºC during 20h. Two types of liquid pyrolysis products, assigned as free oil and bitumen, were isolated and analyzed. Free oil represents free organic phase released by hydrous pyrolysis, whereas bitumen was obtained by extraction from the solid pyrolysis residue with dichloromethane. Changes in the OM maturity were determined using Rock-Eval parameters and biomarker maturity ratios of original sample and pyrolysis products. Biomarker compositions of original sample extract and liquid pyrolysates were used for determination of dominant bacterial source. The yields of free oil and bitumen showed that a microbial mat OM has a high liquid hydrocarbons generation potential. Rock-Eval maturity parameters, biopolymer and biomarker compositions indicate a significant increase of the OM maturity during hydrous pyrolysis. At 280ºC the release of free, adsorbed and occluded compounds was observed; however, without a cracking of the OM. At 330ºC the generation of bitumen and free oil is mostly related to the OM cracking. The highest yield of free oil was recorded at this temperature. Distribution of biomarkers in the extract of original sample and liquid pyrolysates confirms cyanobacteria-dominated microbial mats, whereas the identification of long chain n-alkane series, with maximum at C26, and prominent C30 hop-17(21)-ene additionally suggest the presence of sulfate reducing bacteria. (Author)

  9. Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Miethe, D.; Riis, V.; Stimming, M.

    1996-01-04

    It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen

  10. Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Rue-Van Es, J.E. La.

    1993-05-01

    Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs.

  11. [Bioremediation of petroleum hydrocarbon-contaminated soils by cold-adapted microorganisms: research advance].

    Science.gov (United States)

    Wang, Shi-jie; Wang, Xiang; Lu, Gui-lan; Wang, Qun-hui; Li, Fa-sheng; Guo, Guan-lin

    2011-04-01

    Cold-adapted microorganisms such as psychrotrophs and psychrophiles widely exist in the soils of sub-Arctic, Arctic, Antarctic, alpine, and high mountains, being the important microbial resources for the biodegradation of petroleum hydrocarbons at low temperature. Using the unique advantage of cold-adapted microorganisms to the bioremediation of petroleum hydrocarbon-contaminated soils in low temperature region has become a research hotspot. This paper summarized the category and cold-adaptation mechanisms of the microorganisms able to degrade petroleum hydrocarbon at low temperature, biodegradation characteristics and mechanisms of different petroleum fractions under the action of cold-adapted microorganisms, bio-stimulation techniques for improving biodegradation efficiency, e. g., inoculating petroleum-degrading microorganisms and adding nutrients or bio-surfactants, and the present status of applying molecular biotechnology in this research field, aimed to provide references to the development of bioremediation techniques for petroleum hydrocarbon-contaminated soils.

  12. Microbial activity in soils following steam treatment.

    Science.gov (United States)

    Richardson, Ruth E; James, C Andrew; Bhupathiraju, Vishvesh K; Alvarez-Cohen, Lisa

    2002-01-01

    Steam enhanced extraction (SEE) is an aquifer remediation technique that can be effective at removing the bulk of non-aqueous phase liquid (NAPL) contamination from the subsurface, particularly highly volatile contaminants. However, low volatility compounds such as polynuclear aromatic hydrocarbons (PAHs) are less efficiently removed by this process. This research evaluated the effects of steam injection on soil microbial activity, community structure, and the potential for biodegradation of contaminants following steam treatment. Three different soils were evaluated: a laboratory-prepared microbially-enriched soil, soil from a creosote contaminated field site, and soil from a chlorinated solvent and waste oil contaminated field site. Results from field-scale steaming are also presented. Microbial activity before and after steam treatment was evaluated using direct epifluorescent microscopy (DEM) using the respiratory activity dye 5-cyano-2,3, ditolyl tetrazolium chloride (CTC) in conjunction with the fluorochrome 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF) to yield a quantitative assessment of active and total microbial numbers. DEM results indicate that steamed soils that were analyzed while still hot exhibited microbial activity levels that were below detection. However, soil samples that were slowly cooled, more closely reflecting the conditions of applied SEE, exhibited microbial activity levels that were comparable to presteamed soils. Samples from a field-site where steam was applied continuously for 6 weeks also showed high levels of microbial activity following cooling. The metabolic capabilities of the steamed communities were investigated by measuring cell growth in enrichment cultures on various substrates. These studies provided evidence that organisms capable of biodegradation were among the mesophilic populations that survived steam treatment. Fluorescent in situ hybridization (FISH) analysis of the soils with domain-level rRNA probes suggest

  13. An Algorithm of Association Rule Mining for Microbial Energy Prospection

    Science.gov (United States)

    Shaheen, Muhammad; Shahbaz, Muhammad

    2017-01-01

    The presence of hydrocarbons beneath earth’s surface produces some microbiological anomalies in soils and sediments. The detection of such microbial populations involves pure bio chemical processes which are specialized, expensive and time consuming. This paper proposes a new algorithm of context based association rule mining on non spatial data. The algorithm is a modified form of already developed algorithm which was for spatial database only. The algorithm is applied to mine context based association rules on microbial database to extract interesting and useful associations of microbial attributes with existence of hydrocarbon reserve. The surface and soil manifestations caused by the presence of hydrocarbon oxidizing microbes are selected from existing literature and stored in a shared database. The algorithm is applied on the said database to generate direct and indirect associations among the stored microbial indicators. These associations are then correlated with the probability of hydrocarbon’s existence. The numerical evaluation shows better accuracy for non-spatial data as compared to conventional algorithms at generating reliable and robust rules. PMID:28393846

  14. Cell abundance and microbial community composition along a complete oil sand mining and reclamation process

    Science.gov (United States)

    Lappé, M.; Schneider, B.; Kallmeyer, J.

    2012-12-01

    Hydrocarbons constitute an important energy source for microbes but can also be of environmental concern. Microbial activity causes hydrocarbon degradation and thereby loss of economical value, but also helps to remove hydrocarbons from the environment. The present study characterizes the abundance of microbes along the oil sand mining process in Alberta, Canada, as a first approach to assess the impact of mining and oil extraction on the microbial population. After mining the oil is extracted from the sediment by a hot-water extraction (50-60°C), resulting in three major fractions: crude oil, tailings sand and fine tailings. The tailings sand is used as substratum for newly developing soils on the reclamation areas. The very liquid fine tailings still have a TOC content of about 4.3% and are pumped into tailings ponds, where they need up to three decades to settle and solidify. After deposition, these mature fine tailings (MFTs) are enriched in organics (TOC content between 9.6 and 16.8%) and dredged out of the ponds and put on dumps for several years for dewatering. Finally they are brought out onto the reclamation sites and deposited below the sand layer. Cells were extracted from oily sediments according to the protocol of Lappé and Kallmeyer (2011), stained with SYBR Green I and counted by fluorescence microscopy. Cell abundance in the unprocessed oil sand is around 1.6 x 107 cells cm-3. After processing the fresh fine tailings still contain around 1.6 x 107 cells cm-3. Cell counts in the processed MFTs are 5.8 x 107 cells cm-3, whereas in the sand used as substratum for newly developing soils, they are twice as high (1.4 x 108). In root-bearing horizons, cell counts reach 1.1 x 109 cell cm-3. Cell numbers calculated from cultivation experiments are in the same range. Higher cell counts in the tailings sand are probably due to a higher nitrogen supply through the addition of a 35 cm top layer of a peat-mineral mix. In the sand nitrate concentrations are high

  15. Effect of hydrocarbon to nuclear magnetic resonance (NMR) logging in tight sandstone reservoirs and method for hydrocarbon correction

    Science.gov (United States)

    Xiao, Liang; Mao, Zhi-qiang; Xie, Xiu-hong

    2017-04-01

    It is crucial to understand the behavior of the T2 distribution in the presence of hydrocarbon to properly interpret pore size distribution from NMR logging. The NMR T2 spectrum is associated with pore throat radius distribution under fully brine saturated. However, when the pore space occupied by hydrocarbon, the shape of NMR spectrum is changed due to the bulk relaxation of hydrocarbon. In this study, to understand the effect of hydrocarbon to NMR logging, the kerosene and transformer oil are used to simulate borehole crude oils with different viscosity. 20 core samples, which were separately drilled from conventional, medium porosity and permeability and tight sands are saturated with four conditions of irreducible water saturation, fully saturated with brine, hydrocarbon-bearing condition and residual oil saturation, and the corresponding NMR experiments are applied to acquire NMR measurements. The residual oil saturation is used to simulate field NMR logging due to the shallow investigation depth of NMR logging. The NMR spectra with these conditions are compared, the results illustrate that for core samples drilled from tight sandstone reservoirs, the shape of NMR spectra have much change once they pore space occupied by hydrocarbon. The T2 distributions are wide, and they are bimodal due to the effect of bulk relaxation of hydrocarbon, even though the NMR spectra are unimodal under fully brine saturated. The location of the first peaks are similar with those of the irreducible water, and the second peaks are close to the bulk relaxation of viscosity oils. While for core samples drilled from conventional formations, the shape of T2 spectra have little changes. The T2 distributions overlap with each other under these three conditions of fully brine saturated, hydrocarbon-bearing and residual oil. Hence, in tight sandstone reservoirs, the shape of NMR logging should be corrected. In this study, based on the lab experiments, seven T2 times of 1ms, 3ms, 10ms, 33ms

  16. Application of a Bayesian nonparametric model to derive toxicity estimates based on the response of Antarctic microbial communities to fuel‐contaminated soil

    National Research Council Canada - National Science Library

    Arbel, Julyan; King, Catherine K; Raymond, Ben; Winsley, Tristrom; Mengersen, Kerrie L

    2015-01-01

    ...‐species toxicity tests. In this study, we apply a Bayesian nonparametric model to a soil microbial data set acquired across a hydrocarbon contamination gradient at the site of a fuel spill in Antarctica...

  17. Recovery of Aliphatic Hydrocarbons from Oil Field Sludge using Bacillus sp

    Directory of Open Access Journals (Sweden)

    Rizwan Ahmed Bhutto

    2015-04-01

    Full Text Available Bioremediation of aliphatic HC (Hydrocarbons in the oily sludge of Kunnar oil and gas field, Pakistan was attempted by means of previously isolated and developed Bacillus sp. Both autoclaved and non-autoclaved sludge samples were analyzed for a reaction time of 30 days with pH 7 and temperature of 380C in 50 ml MSM growth media for the sludge concentration of 5, 10 and 50% with 2, 4 and 6ml of Bacillus sp. relatively, in air atmosphere. Stabilization of the samples by microbial activity resulted in the decrease in TPH (Total Petroleum Hydrocarbon concentration by 60, 69 and 87% in autoclaved samples in contrast to the decrease of 70, 84 and 94% observed in non-autoclaved samples, relatively. Hydrocarbon degradation in oily sludge was investigated via GC which transpired that 97 and 99% concentration of aliphatic hydrocarbons in autoclaved and non-autoclaved samples was removed at 5% of TPH concentration, relatively. However, with 10% TPH concentration aliphatic hydrocarbons reduction was 68% in autoclaved samples to that of 87% in non-autoclaved samples. Further increase in the hydrocarbons concentration by 50% yielded in the removal of aliphatic hydrocarbons by 65% in autoclaved samples as compared to 98% decrease in non-autoclaved samples.

  18. Influence of adhesion on aerobic biodegradation and bioremediation of liquid hydrocarbons.

    Science.gov (United States)

    Abbasnezhad, Hassan; Gray, Murray; Foght, Julia M

    2011-11-01

    Biodegradation of poorly water-soluble liquid hydrocarbons is often limited by low availability of the substrate to microbes. Adhesion of microorganisms to an oil-water interface can enhance this availability, whereas detaching cells from the interface can reduce the rate of biodegradation. The capability of microbes to adhere to the interface is not limited to hydrocarbon degraders, nor is it the only mechanism to enable rapid uptake of hydrocarbons, but it represents a common strategy. This review of the literature indicates that microbial adhesion can benefit growth on and biodegradation of very poorly water-soluble hydrocarbons such as n-alkanes and large polycyclic aromatic hydrocarbons dissolved in a non-aqueous phase. Adhesion is particularly important when the hydrocarbons are not emulsified, giving limited interfacial area between the two liquid phases. When mixed communities are involved in biodegradation, the ability of cells to adhere to the interface can enable selective growth and enhance bioremediation with time. The critical challenge in understanding the relationship between growth rate and biodegradation rate for adherent bacteria is to accurately measure and observe the population that resides at the interface of the hydrocarbon phase.

  19. Studies on the effects of H{sub 2}O{sub 2} as an oxygen source in microbial decomposition of hydrocarbons in liquid culture and in near-to-natural bioreactors; Untersuchungen zu den Effekten von H{sub 2}O{sub 2} als Sauerstoffquelle beim mikrobiellen Abbau von Kohlenwasserstoffen in Fluessigkultur und in-s-situ-nahen Bodenreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.G.

    1992-08-12

    Hydrocarbon decomposition in soil with hydrogen peroxide as an oxygen source was examined. Among the model hydrocarbons was diesel fuel. Decomposition in liquid culture was studied in a bioreactor using mixed cultures. Hydrogen peroxide proved its value as an oxygen source. It was found that in soil systems hydrocarbons are largely mineralized and only small amounts of biomass are formed. (VT) [Deutsch] Untersucht wurde der Kohlenwasserstoffabbau im Boden unter Sauerstoffversorgung durch Wasserstoffperoxid. Als Modellkohlenwasserstoff wurde unter anderem Dieseloel eingesetzt. In einem Bioreaktor wurde der Abbau in Fluessigkultur durch Mischkulturen studiert. Wasserstoffperoxid hat sich als Sauerstoffversorger bewaehrt. In Bodensystemen stellte man fest, dass die Kohlenwasserstoffe weitgehend mineralisiert werden und nur wenig Biomasse gebildet wird. (VT)

  20. Benzene, toluene and p-xylene interactions and the role of microbial communities in remediation using bioventing

    Energy Technology Data Exchange (ETDEWEB)

    Sui, H. [Tianjin Univ., Tianjin (China). School of Chemical Engineering and Technology; Tianjin Univ., Tianjin (China). National Engineering Research Center for Distillation Technology; Li, X.G.; Jiang, B. [Tianjin Univ., Tianjin (China). National Engineering Research Center for Distillation Technology

    2005-04-01

    Bioventing is a promising in-situ soil remediation technology used to clean soils and groundwater contaminated by aromatic hydrocarbon components benzene, toluene and xylene (BTX). These contaminants are present at numerous hazardous waste sites. Bioventing provides enough oxygen to stimulate aerobic biodegradation by indigenous microorganisms. It is not constrained by contaminant volatility and can therefore be applied to contaminants that are readily biodegradable even if they are not highly volatile. This study examined the volatilization and biodegradation of BTX during bioventing from unsaturated soil. It focused on the occurrence of any substrate interaction and the effects of indigenous microbial inocula. The soil was inoculated with indigenous microorganisms obtained from the Dagang Oil Field in Tianjin, China. Then, different amounts of BTX were added to the soil in a stainless steel column through which carbon dioxide free air and pure nitrogen flowed. The volatilization-to-biodegradation ratios of BTX were 6:1, 2:1 and 2:1 respectively. After 3 weeks, the final concentration in the soil gas was 0.128 mg/L benzene, 0.377 mg/L toluene and 0.143 mg/L xylene. The substrate interactions that occurred were as follows: benzene and xylene degradation was accelerated while toluene was being degraded; and, the presence of xylene increased the lag period for benzene degradation. It was concluded that bioventing is an effective remediation technology for aromatic hydrocarbons and can significantly reduce the remediation time if target residual BTX concentration of 0.1 mg/L is to be reached. BTX removal becomes more significant with time, particularly when soils are inoculated with indigenous microbial communities from contaminated soil. 22 refs., 5 tabs., 7 figs.

  1. Natural attenuation of hydrocarbon polluted soils in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Linares, L.; Rojas-Avelizapa, N.; Roldan-Carrillo, T.; Islas-Ramirez, M.

    2009-07-01

    Crude oil and hydrocarbon by-proudcts are the most common pollutants in Mexico. In the last years, the two terms, contamination and remediation have being re-defined; also, based on both the scientific advancement and the human risk, the sustentability of remediation technologies and the definition of cleaning levels has been taking place. In this context, the Natural Attenuation of soils is a viable and low cost remediation choice, defined as the degradation of organic compounds without artificial stimulation, through microbial activity including physical processes, such as volatilization, dilution, sorption, and hydraulic dispersion. (Author)

  2. Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

    Science.gov (United States)

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2015-12-01

    Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons.

  3. Influence of xenobiotic contaminants on landfill soil microbial activity and diversity.

    Science.gov (United States)

    Pérez-Leblic, M I; Turmero, A; Hernández, M; Hernández, A J; Pastor, J; Ball, A S; Rodríguez, J; Arias, M E

    2012-03-01

    Landfills are often the final recipient of a range of environmentally important contaminants such as hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). In this study the influence of these contaminants on microbial activity and diversity was assessed in a municipal solid waste (MSW) landfill placed in Torrejón de Ardoz (Madrid, Spain). Soil samples were collected from four selected areas (T2, T2B, T8 and T9) in which the amount of total hydrocarbons, PAHs and PCBs were measured. Soil biomass, substrate induced respiration (SIR) and physiological profiles of soil samples were also determined and used as indicators of total microbial activity. Highest concentration of total hydrocarbons was detected in T2 and T9 samples, with both PCBs and benzopyrene being detected in T9 sample. Results corresponding to microbial estimation (viable bacteria and fungi, and SIR) and microbiological enzyme activities showed that highest values corresponded to areas with the lowest concentration of hydrocarbons (T2B and T8). It is noticeable that in such areas was detected the lowest concentration of the pollutants PAHs and PCBs. A negative significant correlation between soil hydrocarbons concentration and SIR, total bacteria and fungi counts and most of the enzyme activities determined was established. DGGE analysis was also carried out to determine the microbial communities' structure in the soil samples, establishing different profiles of Bacteria and Archaea communities in each analysed area. Through the statistical analysis a significant negative correlation was only found for Bacteria domain when Shannon index and hydrocarbon concentration were correlated. In addition, a bacterial 16S rRNA gene based clone library was prepared from each soil. From the clones analysed in the samples, the majority corresponded to Proteobacteria, followed by Acidobacteria and Actinobacteria. It is important to remark that the most polluted sample (T9) showed

  4. Liquid N and S fertilizer solutions effects on the mass, chemical, and shear strength properties of winter wheat (Triticum aestuvum) residue

    Science.gov (United States)

    To improve stand establishment in high crop residue situations, the utility of fertilizer to stimulate microbial decomposition of residue has been debated. Field experiments assessed winter wheat (Triticum aestivum) straw decomposition under different fertilizer rates and application timings at thre...

  5. A Literature Survey and Data Base Assessment: Microbial Fate of Diesel Fuel and Fog Oils,

    Science.gov (United States)

    1986-04-01

    were mostly aerobic NocardLa species and fungi. Cladosporum resinae , which has been repeatedly found as a contaminant of jet fuels and has been...1,13 2 Glucose metabolism is subject to inhibition or repression by hydrocarbon in a Candida strain 1 3 3 and Cladosporium resinae .1 3 ,1 5 Microbial...microorganisms isolated from soil. Can. J. Microbiol. 14:403. 93. Cooney, J.J. and J.D. Walker. 1973. Hydrocarbon utilization by Cladosporium resinae

  6. Hydrocarbon Leak Detection Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT is proposing the development of a sensor to detect the presence of hydrocarbons in turbopump Inter-Propellant Seals (IPS). The purpose of the IPS is to prevent...

  7. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  8. Degradation Characteristics and Community Structure of a Hydrocarbon Degrading Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    Li Zheng; Gu Guizhou; Zhao Chaocheng; Zhao Dongfeng

    2015-01-01

    A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9%of 10 g/L total petroleum hydrocarbons (TPH) at 30℃after 7 days of incu-bation, and could also remove 100%of lfuorene, 98.93%of phenanthrene and 65.73%of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis (DGGE) was used to investigate the microbial community shifts in ifve different carbon sources (including TPH, saturated hydrocarbons, lfuorene, phenanthrene and pyrene). The test results indi-cated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudo-monas sp. could survive in the ifve kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that speciifc bacterial phylotypes were associated with different contaminants and complex interactions between bacterial spe-cies, and the medium conditions inlfuenced the biodegradation capacity of the microbial communities involved in bioreme-diation processes.

  9. Isolation and functional characterization of hydrocarbon emulsifying and solubilizing factors produced by a Pseudomonas species

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, P.G.; Banuah, J.N.; Bhagat, S.D.; Pathak, M.G.; Singh, H.D.

    1983-02-01

    Pseudomonas PG-1 cultivated on pristane produced in good amount a heat-stable polymeric substance which showed strong hydrocarbon emulsifying and solubilizing properties. The substance was isolated in crude form and was found to contain 34% protein, 16% carbohydrate, and 40% lipid. The hydrocarbon solubilizing activity of the isolate was strongly inhibited by EDTA but the chelating agent had no effect on the hydrocarbon emulsifying activity. Both activities of the isolate were strongly inhibited by chymotrypsin treatment indicating the importance of the protein moiety for its activity. Hydrocarbon solubilization by the isolate showed a certain degree of specificity to pristane in modest agitation generally used in microbial cultivation, but this specificity was lost by vigorous agitation in a Waring blender. It was proposed that in the first case, solubilization was effected by a solubilizing factor specific to pristane, whereas in the latter ease, nonspecific solubilization occurred due to the action of the emulsifying factor. The rate of pristane solubilization by heat-treated culture broth under the conditions of agitation used in cultivation (rotary shaker, 120 rpm) was found to be ca. 750 mg L/sup -1/h/sup -1/ which was much larger than the maximal pristane uptake rate of 170 mg L/sup -1/h/sup -1/ observed during microbial growth on the substrate. It was concluded that hydrocarbon solubilization could satisfactorily account for the substrate uptake and growth.

  10. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  11. Electrochemical decomposition of chlorinated hydrocarbons

    OpenAIRE

    McGee, Gerard Anthony

    1993-01-01

    This work involves the characterisation of the electrochemical decomposition of chlorinated hydrocarbons. A variety of methods were employed involving the use of catalytic reagents to enhance the rate at which chlorinated organic compounds are reduced. The first reagent used was oxygen which was electrochemically reduced to superoxide in nonaqueous solvents. Superoxide is a reactive intermediate and decomposes chlorinated hydrocarbons. However it was found that since the rate of reaction betw...

  12. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  13. LIQUID HYDROCARBON FUEL CELL DEVELOPMENT.

    Science.gov (United States)

    A compound anode consists of a reforming catalyst bed in direct contact with a palladium-silver fuel cell anode. The objective of this study was to...prove the feasibility of operating a compound anode fuel cell on a liquid hydrocarbon and to define the important parameters that influence cell...performance. Both reformer and fuel cell tests were conducted with various liquid hydrocarbon fuels. Included in this report is a description of the

  14. Microbial processes in the Athabasca Oil Sands and their potential applications in microbial enhanced oil recovery.

    Science.gov (United States)

    Harner, N K; Richardson, T L; Thompson, K A; Best, R J; Best, A S; Trevors, J T

    2011-11-01

    The Athabasca Oil Sands are located within the Western Canadian Sedimentary Basin, which covers over 140,200 km(2) of land in Alberta, Canada. The oil sands provide a unique environment for bacteria as a result of the stressors of low water availability and high hydrocarbon concentrations. Understanding the mechanisms bacteria use to tolerate these stresses may aid in our understanding of how hydrocarbon degradation has occurred over geological time, and how these processes and related tolerance mechanisms may be used in biotechnology applications such as microbial enhanced oil recovery (MEOR). The majority of research has focused on microbiology processes in oil reservoirs and oilfields; as such there is a paucity of information specific to oil sands. By studying microbial processes in oil sands there is the potential to use microbes in MEOR applications. This article reviews the microbiology of the Athabasca Oil Sands and the mechanisms bacteria use to tolerate low water and high hydrocarbon availability in oil reservoirs and oilfields, and potential applications in MEOR.

  15. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  16. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  17. New Insight into the Kinetics of Deep Liquid Hydrocarbon Cracking and Its Significance

    Directory of Open Access Journals (Sweden)

    Wenzhi Zhao

    2017-01-01

    Full Text Available The deep marine natural gas accumulations in China are mainly derived from the cracking of liquid hydrocarbons with different occurrence states. Besides accumulated oil in reservoir, the dispersed liquid hydrocarbon in and outside source also is important source for cracking gas generation or relayed gas generation in deep formations. In this study, nonisothermal gold tube pyrolysis and numerical calculations as well as geochemical analysis were conducted to ascertain the expulsion efficiency of source rocks and the kinetics for oil cracking. By determination of light liquid hydrocarbons and numerical calculations, it is concluded that the residual bitumen or hydrocarbons within source rocks can occupy about 50 wt.% of total oil generated at oil generation peak. This implies that considerable amounts of natural gas can be derived from residual hydrocarbon cracking and contribute significantly to the accumulation of shale gas. Based on pyrolysis experiments and kinetic calculations, we established a model for the cracking of oil and its different components. In addition, a quantitative gas generation model was also established to address the contribution of the cracking of residual oil and expulsed oil for natural gas accumulations in deep formations. These models may provide us with guidance for gas resource evaluation and future gas exploration in deep formations.

  18. Microbial conversions of terpenoids

    OpenAIRE

    Parshikov, Igor A

    2015-01-01

    The monograph describes examples of the application of microbial technology for obtaining of derivatives of terpenoids. Obtaining new derivatives of terpenoids, including artemisinin derivatives with increased antimalarial activity, is an important goal of research in microbial biotechnology and medicinal chemistry.

  19. Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function

    Energy Technology Data Exchange (ETDEWEB)

    George, S.J.; Sherbone, J.; Hinz, C. [Centre for Land Rehabilitation, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Tibbett, M., E-mail: m.tibbett@cranfield.ac.uk [Centre for Land Rehabilitation, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2011-10-15

    Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons. - Highlights: > Effects of flowline additives on soil structure and microbial function highlighted. > Phosphonate salts (in scale inhibitor) were found to disrupt soil physical structure. > Glutaraldehyde (in biocides) caused significant reduction of hydrocarbon degradation in soil. > Flowline additive chemicals synergistically affects soil structure and remediative microbial function. - Scale inhibitor and biocide oilfield flowline additives interactively affect soil physical and microbial properties

  20. Linking microbial carbon utilization with microbially-derived soil organic matter

    Science.gov (United States)

    Kallenbach, Cynthia M.; Grandy, A. Stuart

    2014-05-01

    Soil microbial communities are fundamental to plant C turnover, as all C inputs eventually pass through the microbial biomass. In turn, there is increasing evidence that this biomass accumulates as a significant portion of stable soil organic matter (SOM) via physiochemical interactions with the soil matrix. However, when exploring SOM dynamics, these two processes are often regarded as discrete from one another, despite potentially important linkages between microbial C utilization and the fate of that biomass C as SOM. Specifically, if stable SOM is largely comprised of microbial products, we need to better understand the soil C inputs that influence microbial biomass production and microbial C allocation. Microbial physiology, such as microbial growth efficiency (MGE), growth rate and turnover have direct influences on microbial biomass production and are highly sensitive to resource quality. Therefore, the importance of resource quality on SOM accumulation may not necessarily be a function of resistance to decay but the degree to which it optimizes microbial biomass production. To examine the relationship between microbial C utilization and microbial contributions to SOM, an ongoing 15-mo incubation experiment was set up using artificial, initially C- and microbial-free soils. Soil microcosms were constructed by mixing sand with either kaolinite or montmorillonite clays followed with a natural soil microbial inoculum. For both soil mineral treatments, weekly additions of glucose, cellobiose, or syringol are carried out, with an additional treatment of plant leachate to serve as a reference. This simplified system allows us to determine 1) if, in absence of plant-derived C, chemically complex SOM similar to natural soils can accumulate through the production of microbial residues and 2) how differences in C utilization of simple substrates, varying in energy yields, influence the quantity and chemistry of newly formed SOM. Over the course of the incubation, MGE

  1. 处理甜菜加工副产物微生物燃料电池阳极生物膜群落多样性研究%Diverse Microbial Communities in Microbial Fuel Cells with Sugar Beet Residue as Substrate

    Institute of Scientific and Technical Information of China (English)

    梅晓雪; 吴迪; 王明波

    2015-01-01

    [目的]分析处理甜菜加工副产物微生物燃料电池(Microbial fuel cell,MFC)阳极生物膜群落多样性.[方法]以不同处理方式下的甜菜渣作为底物,以MFC为研究装置,考察其产电性能,并通过454焦磷酸测序技术分析不同处理MFC中形成阳极群落结构差异,探讨其运行的可行性、稳定性.[结果]不同甜菜渣预处理方式对MFC电能输出有影响,以碱处理和未处理的甜菜渣产生的电压高于酸处理.16S rRNA基因的焦磷酸测序结果显示,3个样品中共有14个门,其中变形菌门为优势门.由聚类分析可知,酸处理与未处理和碱处理的微生物群落构成差异明显.微生物群落中存在多种产酸菌(Paludibacter、Petrimonas以及Spirochaeta等)和产电菌(主要为Geobacter属),它们之间存在种群互养关系.产酸菌能够发酵可溶性糖或者降解纤维素产生有机酸,产电菌可以利用这些有机酸直接产电.[结论]研究证实,甜菜渣不同的处理方式导致阳极群落多样性存在差异,而阳极群落结构的不同影响微生物燃料电池电能的输出.

  2. Microfluidics and microbial engineering.

    Science.gov (United States)

    Kou, Songzi; Cheng, Danhui; Sun, Fei; Hsing, I-Ming

    2016-02-01

    The combination of microbial engineering and microfluidics is synergistic in nature. For example, microfluidics is benefiting from the outcome of microbial engineering and many reported point-of-care microfluidic devices employ engineered microbes as functional parts for the microsystems. In addition, microbial engineering is facilitated by various microfluidic techniques, due to their inherent strength in high-throughput screening and miniaturization. In this review article, we firstly examine the applications of engineered microbes for toxicity detection, biosensing, and motion generation in microfluidic platforms. Secondly, we look into how microfluidic technologies facilitate the upstream and downstream processes of microbial engineering, including DNA recombination, transformation, target microbe selection, mutant characterization, and microbial function analysis. Thirdly, we highlight an emerging concept in microbial engineering, namely, microbial consortium engineering, where the behavior of a multicultural microbial community rather than that of a single cell/species is delineated. Integrating the disciplines of microfluidics and microbial engineering opens up many new opportunities, for example in diagnostics, engineering of microbial motors, development of portable devices for genetics, high throughput characterization of genetic mutants, isolation and identification of rare/unculturable microbial species, single-cell analysis with high spatio-temporal resolution, and exploration of natural microbial communities.

  3. Childhood microbial keratitis

    Directory of Open Access Journals (Sweden)

    Abdullah G Al Otaibi

    2012-01-01

    Conclusion: Children with suspected microbial keratitis require comprehensive evaluation and management. Early recognition, identifying the predisposing factors and etiological microbial organisms, and instituting appropriate treatment measures have a crucial role in outcome. Ocular trauma was the leading cause of childhood microbial keratitis in our study.

  4. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  5. Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Jonker, M.T.O.; Sinke, A.; Brils, J.M.; Murk, A.J.; Koelmans, A.A.

    2006-01-01

    Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAHs), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a seminatur

  6. Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Jonker, M.T.O.; Sinke, A.; Brils, J.M.; Murk, A.J.; Koelmans, A.A.

    2006-01-01

    Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAHs), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a

  7. Long-term oil contamination causes similar changes in microbial communities of two distinct soils.

    Science.gov (United States)

    Liao, Jingqiu; Wang, Jie; Jiang, Dalin; Wang, Michael Cai; Huang, Yi

    2015-12-01

    Since total petroleum hydrocarbons (TPH) are toxic and persistent in environments, studying the impact of oil contamination on microbial communities in different soils is vital to oil production engineering, effective soil management and pollution control. This study analyzed the impact of oil contamination on the structure, activity and function in carbon metabolism of microbial communities of Chernozem soil from Daqing oil field and Cinnamon soil from Huabei oil field through both culture-dependent techniques and a culture-independent technique-pyrosequencing. Results revealed that pristine microbial communities in these two soils presented disparate patterns, where Cinnamon soil showed higher abundance of alkane, (polycyclic aromatic hydrocarbons) PAHs and TPH degraders, number of cultivable microbes, bacterial richness, bacterial biodiversity, and stronger microbial activity and function in carbon metabolism than Chernozem soil. It suggested that complicated properties of microbes and soils resulted in the difference in soil microbial patterns. However, the changes of microbial communities caused by oil contamination were similar in respect of two dominant phenomena. Firstly, the microbial community structures were greatly changed, with higher abundance, higher bacterial biodiversity, occurrence of Candidate_division_BRC1 and TAO6, disappearance of BD1-5 and Candidate_division_OD1, dominance of Streptomyces, higher percentage of hydrocarbon-degrading groups, and lower percentage of nitrogen-transforming groups. Secondly, microbial activity and function in carbon metabolism were significantly enhanced. Based on the characteristics of microbial communities in the two soils, appropriate strategy for in situ bioremediation was provided for each oil field. This research underscored the usefulness of combination of culture-dependent techniques and next-generation sequencing techniques both to unravel the microbial patterns and understand the ecological impact of

  8. Mechanism of acetaldehyde-induced deactivation of microbial lipases

    OpenAIRE

    Jaeger Karl E; Eggert Thorsten; Franken Benjamin; Pohl Martina

    2011-01-01

    Abstract Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were ...

  9. Bioaugmentation and biostimulation as strategies for the bioremediation of a burned woodland soil contaminated by toxic hydrocarbons: a comparative study.

    Science.gov (United States)

    Andreolli, Marco; Lampis, Silvia; Brignoli, Pierlorenzo; Vallini, Giovanni

    2015-04-15

    In this work, the natural attenuation strategy (no soil amendments done) was compared with two different bioremediation approaches, namely bioaugmentation through soil inoculation with a suspension of Trichoderma sp. mycelium and biostimulation by soil addition with a microbial growth promoting formulation, in order to verify the effectiveness of these methods in terms of degradation efficiency towards toxic hydrocarbons, with particular attention to the high molecular weight (HMW) fraction, in a forest area impacted by recent wildfire in Northern Italy. The area under investigation, divided into three parcels, was monitored to figure out the dynamics of decay in soil concentration of C₁₂₋₄₀ hydrocarbons (including isoalkanes, cycloalkanes, alkyl-benzenes and alkyl-naphthalenes besides PAHs) and low molecular weight (LMW) PAHs, following the adoption of the foregoing different remediation strategies. Soil hydrocarbonoclastic potential was even checked by characterizing the autochthonous microbial cenoses. Field experiments proved that the best performance in the abatement of HMW hydrocarbons was reached 60 days after soil treatment through the biostimulation protocol, when about 70% of the initial concentration of HMW hydrocarbons was depleted. Within the same time, about 55% degradation was obtained with the bioaugmentation protocol, whilst natural attenuation allowed only a 45% removal of the starting C12-40 hydrocarbon fraction. Therefore, biostimulation seems to significantly reduce the time required for the remediation, most likely because of the enhancement of microbial degradation through the improvement of nutrient balance in the burned soil.

  10. Metagenomes from two microbial consortia associated with Santa Barbara seep oil.

    Science.gov (United States)

    Hawley, Erik R; Malfatti, Stephanie A; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Foster, Brian; Copeland, Alexander; del Rio, Tijana Glavina; Pati, Amrita; Jansson, Janet R; Gilbert, Jack A; Tringe, Susannah Green; Lorenson, Thomas D; Hess, Matthias

    2014-12-01

    The metagenomes from two microbial consortia associated with natural oils seeping into the Pacific Ocean offshore the coast of Santa Barbara (California, USA) were determined to complement already existing metagenomes generated from microbial communities associated with hydrocarbons that pollute the marine ecosystem. This genomics resource article is the first of two publications reporting a total of four new metagenomes from oils that seep into the Santa Barbara Channel.

  11. An Analysis of Microbial Contamination in Military Aviation Fuel Systems

    Science.gov (United States)

    2003-03-01

    aircraft. Multiple samples were taken of the various tanks due to the recent drop in average ambient temperatures (normal winter season), which led...Relationship With Fuel Fouling,” Revista Argentina de Microbiologia 30:105-114. 1998. Finefrock, V. H. and London, S. A. Microbial...Hydrocarbon Fuels and Its Control,” Revista de Microbiologia 30:01-10. 1999. Geiss, K. T. and Frazier, J. M. “In Vitro Toxicities of Experimental

  12. Assessment of five bioaccessibility assays for predicting the efficacy of petroleum hydrocarbon biodegradation in aged contaminated soils.

    Science.gov (United States)

    Dandie, Catherine E; Weber, John; Aleer, Samuel; Adetutu, Eric M; Ball, Andy S; Juhasz, Albert L

    2010-11-01

    In this study, the bioaccessibility of petroleum hydrocarbons in aged contaminated soils (1.6-67gkg(-1)) was assessed using four non-exhaustive extraction techniques (100% 1-butanol, 100% 1-propanol, 50% 1-propanol in water and hydroxypropyl-β-cyclodextrin) and the persulfate oxidation method. Using linear regression analysis, residual hydrocarbon concentrations following bioaccessibility assessment were compared to residual hydrocarbon concentrations following biodegradation in laboratory-scale microcosms in order to determine whether bioaccessibility assays can predict the endpoint of hydrocarbon biodegradation. The relationship between residual hydrocarbon concentrations following microcosm biodegradation and bioaccessibility assessment was linear (r(2)=0.71-0.97) indicating that bioaccessibility assays have the potential to predict the extent of hydrocarbon biodegradation. However, the slope of best fit varied depending on the hydrocarbon fractional range assessed. For the C(10)-C(14) hydrocarbon fraction, the slope of best fit ranged from 0.12 to 0.27 indicating that the non-exhaustive or persulfate oxidation methods removed 3.5-8 times more hydrocarbons than biodegradation. Conversely, for the higher molecular weight hydrocarbon fractions (C(29)-C(36) and C(37)-C(40)), biodegradation removed up to 3.3 times more hydrocarbons compared to bioaccessibility assays with the resulting slope of best fit ranging from 1.0-1.9 to 2.0-3.3 respectively. For mid-range hydrocarbons (C(15)-C(28)), a slope of approximately one was obtained indicating that C(15)-C(28) hydrocarbon removal by these bioaccessibility assays may approximate the extent of biodegradation. While this study demonstrates the potential of predicting biodegradation endpoints using bioaccessibility assays, limitations of the study include a small data set and that all soils were collected from a single site, presumably resulting from a single contamination source. Further evaluation and validation is

  13. Successful bioremediation of an aged and heavily contaminated soil using a microbial/plant combination strategy.

    Science.gov (United States)

    Xu, Yang; Sun, Guang-Dong; Jin, Jing-Hua; Liu, Ying; Luo, Mu; Zhong, Zhi-Ping; Liu, Zhi-Pei

    2014-01-15

    Bioremediation of an aged and heavily contaminated soil was performed using microbial remediation, phytoremediation, and microbial/phytoremediation. The removal efficiency of polycyclic aromatic hydrocarbons (PAHs) was in the order microbial/phytoremediation>microbial remediation≈phytoremediation>control. The removal percentage of microbial/phytoremediation (69.6%) was twice that of control. Kocuria sp. P10 significantly enhanced PAH removal (Psoil microbial communities were also detected by pyrosequencing. The results indicated that biodiversity of the soil bacterial community gradually increased with time and was slightly lower in control, as indicated by operational taxonomic unit (OTU) numbers and Shannon-Wiener indices. Proportions of Betaproteobacteria and Gammaproteobacteria were consistently high in all groups. Actinobacteridae were initially predominant (>37.8%) but rapidly decreased to bioremediation process and a possible basis for ecological assessment for bioremediation on a large scale.

  14. The formation of bound residues of diazinon in four UK soils: Implications for risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Fenlon, Katie A., E-mail: katefenlon@hotmail.com [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Andreou, Kostas; Jones, Kevin C.; Semple, Kirk T. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2011-03-15

    The behaviour of diazinon in the soil determines the likelihood of further pollution incidents, particularly leaching to water. The most significant processes in the control of the fate of diazinon in the soil are microbial degradation and the formation of bound residues. Soils from four sites in the UK were amended with diazinon and its {sup 14}C labelled analogue and incubated for 100 days. After 0, 10, 21, 50 and 100 days, the formation of bound residues was assessed by solvent extraction, and the microbial degradation of diazinon by mineralisation assay. In microbially active soils, diazinon is degraded rapidly, reducing the risk of future pollution incidents. However, where there was limited mineralisation there was also significantly lower formation of bound residues, which may lead to water pollution via leaching. The formation of bound residues was dependent on extraction type. Acetonitrile extraction identified bound residues in all soils, with the bound residue fraction increasing with increasing incubation time. - Research highlights: > Bound residues are defined by extraction method. > Microbial degradation is limited by the formation of bound residues. > Bioavailability of diazinon maybe estimated by chemical extraction. - The formation of bound residues and biodegradation of diazinon are dependent on soil type and the presence of degrading bacteria.

  15. Advanced microbial check valve development

    Science.gov (United States)

    Colombo, G. V.; Greenley, D. R.

    1980-01-01

    A flight certified assembly identified as a Microbial Check Valve (MCV) was developed and tested. The MCV is a canister packed with an iodinated anionic exchange resin. The device is used to destroy organisms in a water stream as the water passes through the device. The device is equally effective for fluid flow in either direction and its primary method of organism removal is killing rather than filtering. The MCV was successfully developed for the space shuttle to: disinfect fuel cell water; and prevent back contamination of the stored potable water supply. One version of the device consists of a high residual iodinated resin bed that imparts approximately 2 ppm of iodine to the fuel cell water as it flows to the potable water tanks. A second version of the device consists of a low residual iodinated resin bed. One of these low residual beds is located at each use port in the potable water system for the dual purpose of removing some iodine from the potable water as it is dispensed and also to prevent back contamination of the potable supply.

  16. Biodegradation, bioaccessibility, and genotoxicity of diffuse polycyclic aromatic hydrocarbon (PAH) pollution at a motorway site.

    Science.gov (United States)

    Johnsen, Anders R; De Lipthay, Julia R; Reichenberg, Fredrik; Sørensen, Søren J; Andersen, Ole; Christensen, Peter; Binderup, Mona-lise; Jacobsen, Carsten S

    2006-05-15

    Diffuse pollution of surface soil with polycyclic aromatic hydrocarbons (PAHs) is problematic in terms of the large areas and volumes of polluted soil. The levels and effects of diffuse PAH pollution at a motorway site were investigated. Surface soil was sampled with increasing distance from the asphalt pavement and tested for total amounts of PAHs, amounts of bioaccessible PAHs, total bacterial populations, PAH degrader populations, the potential for mineralization of 14C-PAHs, and mutagenicity. Elevated PAH concentrations were found in the samples taken 1-8 m from the pavement. Soil sampled at greater distances (12-24 m) contained only background levels of PAHs. The total bacterial populations (CFU and numbers of 16S rDNA genes) were similar for all soil samples, whereas the microbial degrader populations (culturable PAH degraders and numbers of PAH dioxygenase genes) were most abundant in the most polluted samples close to the pavement. Hydroxypropyl-beta-cyclodextrin extraction of soil PAHs, as a direct estimate of the bioaccessibility, indicated that only 1-5% of the PAHs were accessible to soil bacteria. This low bioaccessibility is suggested to be due to sorption to traffic soot particles. The increased PAH level close to the pavement was reflected in slightly increased mutagenic activity (1 m, 0.32 +/- 0.08 revertants g(-1) soil; background/ 24 m: 0.08 +/- 0.04), determined by the Salmonella/ microsome assay of total extractable PAHs activated by liver enzymes. The potential for lighter molecular weight PAH degradation in combination with low bioaccessibility of heavier PAHs is proposed to lead to a likely increase in concentration of heavier PAHs over time. These residues are, however, likely to be of low biological significance.

  17. Influence of pretreatment of agriculture residues on phytase ...

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... Various agriculture residues such as rice bran, de-oiled rice bran, wheat bran ... Protein concentration in the culture filtrate was determined by the method of Lowry et al. ... microbial phytase in soybean meal based broiler diets ...

  18. Bioinformatic Approaches Including Predictive Metagenomic Profiling Reveal Characteristics of Bacterial Response to Petroleum Hydrocarbon Contamination in Diverse Environments.

    Science.gov (United States)

    Mukherjee, Arghya; Chettri, Bobby; Langpoklakpam, James S; Basak, Pijush; Prasad, Aravind; Mukherjee, Ashis K; Bhattacharyya, Maitree; Singh, Arvind K; Chattopadhyay, Dhrubajyoti

    2017-04-24

    Microbial remediation of oil polluted habitats remains one of the foremost methods for restoration of petroleum hydrocarbon contaminated environments. The development of effective bioremediation strategies however, require an extensive understanding of the resident microbiome of these habitats. Recent developments such as high-throughput sequencing has greatly facilitated the advancement of microbial ecological studies in oil polluted habitats. However, effective interpretation of biological characteristics from these large datasets remain a considerable challenge. In this study, we have implemented recently developed bioinformatic tools for analyzing 65 16S rRNA datasets from 12 diverse hydrocarbon polluted habitats to decipher metagenomic characteristics of the resident bacterial communities. Using metagenomes predicted from 16S rRNA gene sequences through PICRUSt, we have comprehensively described phylogenetic and functional compositions of these habitats and additionally inferred a multitude of metagenomic features including 255 taxa and 414 functional modules which can be used as biomarkers for effective distinction between the 12 oil polluted sites. Additionally, we show that significantly over-represented taxa often contribute to either or both, hydrocarbon degradation and additional important functions. Our findings reveal significant differences between hydrocarbon contaminated sites and establishes the importance of endemic factors in addition to petroleum hydrocarbons as driving factors for sculpting hydrocarbon contaminated bacteriomes.

  19. Fate and degradation of petroleum hydrocarbons in stormwater bioretention cells

    Science.gov (United States)

    LeFevre, Gregory Hallett

    This dissertation describes the investigation of the fate of hydrocarbons in stormwater bioretention areas and those mechanisms that affect hydrocarbon fate in such systems. Seventy-five samples from 58 bioretention areas were collected and analyzed to measure total petroleum hydrocarbon (TPH) residual and biodegradation functional genes. TPH residual in bioretention areas was greater than background sites but low overall (biodegradation. Field soils were capable of mineralizing naphthalene, a polycyclic aromatic hydrocarbon (PAH) when incubated in the laboratory. In an additional laboratory investigation, a column study was initiated to comprehensively determine naphthalene fate in a simulated bioretention cell using a 14C-labeled tracer. Sorption to soil was the greatest sink of naphthalene in the columns, although biodegradation and vegetative uptake were also important loss mechanisms. Little leaching occurred following the first flush, and volatilization was insignificant. Significant enrichment of naphthalene degrading bacteria occurred over the course of the experiment as a result of naphthalene exposure. This was evident from enhanced naphthalene biodegradation kinetics (measured via batch tests), significant increases in naphthalene dioxygenase gene quantities, and a significant correlation observed between naphthalene residual and biodegradation functional genes. Vegetated columns outperformed the unplanted control column in terms of total naphthalene removal and biodegradation kinetics. As a result of these experiments, a final study focused on why planted systems outperform unplanted systems was conducted. Plant root exudates were harvested from hydroponic setups for three types of plants. Additionally, a solution of artificial root exudates (AREs) as prepared. Exudates were digested using soil bacteria to create metabolized exudates. Raw and metabolized exudates were characterized for dissolved organic carbon, specific UV absorbance, spectral slope

  20. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang; Dali; Devlin, David; Barbero, Robert S.; Carrera, Martin E.; Colling, Craig W.

    2010-08-10

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  1. Sophorolipids production by Candida bombicola ATCC 22214 and its potential application in microbial enhanced oil recovery

    Directory of Open Access Journals (Sweden)

    Abdulkadir E. Elshafie

    2015-11-01

    Full Text Available Biosurfactant production using Candida bombicola ATCC 22214, its characterization and potential applications in enhancing oil recovery was studied at laboratory scale. The seed media and the production media were standardized for optimal growth and biosurfactant production. The production media were tested with different carbon sources: glucose (2%w/v and, corn oil (10%v/v added separately or concurrently. The samples were collected at 24h interval up to 120h and checked for growth (OD660, and biosurfactant production (Surface tension and Interfacial tension. The medium with both glucose and corn oil gave better biosurfactant production and reduced both surface tension and interfacial tension to 28.56 + 0.42mN/m and 2.13 + 0.09mN/m, respectively within 72h. The produced biosurfactant was quite stable at 13-15% salinity, pH range of 2-12, and at temperature up to 100°C. It also produced stable emulsions (%E24 with different hydrocarbons (pentane, hexane, heptane, tridecane, tetradecane, hexadecane, 1-methylnaphthalene, 2,2,4,4,6,8-heptamethylnonane, light and heavy crude oil. The produced biosurfactant was extracted using ethyl acetate and characterized as a mixture of sophorolipids. The potential of sophorolipids in enhancing oil recovery was tested using core-flooding experiments, under reservoir conditions, where additional 27.27% of residual oil (Sor was recovered. This confirmed the potential of sophorolipids for applications in microbial enhanced oil recovery.

  2. Sophorolipids Production by Candida bombicola ATCC 22214 and its Potential Application in Microbial Enhanced Oil Recovery.

    Science.gov (United States)

    Elshafie, Abdulkadir E; Joshi, Sanket J; Al-Wahaibi, Yahya M; Al-Bemani, Ali S; Al-Bahry, Saif N; Al-Maqbali, Dua'a; Banat, Ibrahim M

    2015-01-01

    Biosurfactant production using Candida bombicola ATCC 22214, its characterization and potential applications in enhancing oil recovery were studied at laboratory scale. The seed media and the production media were standardized for optimal growth and biosurfactant production. The production media were tested with different carbon sources: glucose (2%w/v) and corn oil (10%v/v) added separately or concurrently. The samples were collected at 24 h interval up to 120 h and checked for growth (OD660), and biosurfactant production [surface tension (ST) and interfacial tension (IFT)]. The medium with both glucose and corn oil gave better biosurfactant production and reduced both ST and IFT to 28.56 + 0.42mN/m and 2.13 + 0.09mN/m, respectively within 72 h. The produced biosurfactant was quite stable at 13-15% salinity, pH range of 2-12, and at temperature up to 100°C. It also produced stable emulsions (%E24) with different hydrocarbons (pentane, hexane, heptane, tridecane, tetradecane, hexadecane, 1-methylnaphthalene, 2,2,4,4,6,8-heptamethylnonane, light and heavy crude oil). The produced biosurfactant was extracted using ethyl acetate and characterized as a mixture of sophorolipids (SPLs). The potential of SPLs in enhancing oil recovery was tested using core-flooding experiments under reservoir conditions, where additional 27.27% of residual oil (Sor) was recovered. This confirmed the potential of SPLs for applications in microbial enhanced oil recovery.

  3. Evaluating the Metal Tolerance Capacity of Microbial Communities Isolated from Alberta Oil Sands Process Water.

    Directory of Open Access Journals (Sweden)

    Mathew L Frankel

    Full Text Available Anthropogenic activities have resulted in the intensified use of water resources. For example, open pit bitumen extraction by Canada's oil sands operations uses an estimated volume of three barrels of water for every barrel of oil produced. The waste tailings-oil sands process water (OSPW-are stored in holding ponds, and present an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous OSPW microbial communities have an enhanced tolerance to heavy metals, we tested the capacity of planktonic and biofilm populations from OSPW to withstand metal ion challenges, using Cupriavidus metallidurans, a known metal-resistant organism, for comparison. The toxicity of the metals toward biofilm and planktonic bacterial populations was determined by measuring the minimum biofilm inhibitory concentrations (MBICs and planktonic minimum inhibitory concentrations (MICs using the MBEC ™ assay. We observed that the OSPW community and C. metallidurans had similar tolerances to 22 different metals. While thiophillic elements (Te, Ag, Cd, Ni were found to be most toxic, the OSPW consortia demonstrated higher tolerance to metals reported in tailings ponds (Al, Fe, Mo, Pb. Metal toxicity correlated with a number of physicochemical characteristics of the metals. Parameters reflecting metal-ligand affinities showed fewer and weaker correlations for the community compared to C. metallidurans, suggesting that the OSPW consortia may have developed tolerance mechanisms toward metals present in their environment.

  4. Field Evidence for Magnetite Formation by a Methanogenic Microbial Community

    Science.gov (United States)

    Rossbach, S.; Beaver, C. L.; Williams, A.; Atekwana, E. A.; Slater, L. D.; Ntarlagiannis, D.; Lund, A.

    2015-12-01

    The aged, subsurface petroleum spill in Bemidji, Minnesota, has been surveyed with magnetic susceptibility (MS) measurements. High MS values were found in the free-product phase around the fluctuating water table. Although we had hypothesized that high MS values are related to the occurrence of the mineral magnetite resulting from the activity of iron-reducing bacteria, our microbial analysis pointed to the presence of a methanogenic microbial community at the locations and depths of the highest MS values. Here, we report on a more detailed microbial analysis based on high-throughput sequencing of the 16S rRNA gene of sediment samples from four consecutive years. In addition, we provide geochemical data (FeII/FeIII concentrations) to refine our conceptual model of methanogenic hydrocarbon degradation at aged petroleum spills and demonstrate that the microbial induced changes of sediment properties can be monitored with MS. The methanogenic microbial community at the Bemidji site consisted mainly of the syntrophic, hydrocarbon-degrading Smithella and the hydrogenotrophic, methane-generating Methanoregula. There is growing evidence in the literature that not only Bacteria, but also some methanogenic Archaea are able to reduce iron. In fact, a recent study reported that the methanogen Methanosarcina thermophila produced magnetite during the reduction of ferrihydrite in a laboratory experiment when hydrogen was present. Therefore, our finding of high MS values and the presence of magnetite in the methanogenic zone of an aged, subsurface petroleum spill could very well be the first field evidence for magnetite formation during methanogenic hydrocarbon degradation.

  5. The bacterial community structure of hydrocarbon-polluted marine environments as the basis for the definition of an ecological index of hydrocarbon exposure.

    Science.gov (United States)

    Lozada, Mariana; Marcos, Magalí S; Commendatore, Marta G; Gil, Mónica N; Dionisi, Hebe M

    2014-09-17

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

  6. Evaluation of microbial contents of table eggs at retail outlets in ...

    African Journals Online (AJOL)

    ADEYEYE

    2015-02-23

    Feb 23, 2015 ... Keywords: Bacterial isolation, Microbial contents, Retail outlets, Sokoto, Table eggs. Received: ... very nutritious and a cheap source of protein. (Blumenthal ... The possible transmission of such toxic residues to edible eggs.

  7. Citrate and malonate increase microbial activity and alter microbial community composition in uncontaminated and diesel-contaminated soil microcosms

    Science.gov (United States)

    Martin, Belinda C.; George, Suman J.; Price, Charles A.; Shahsavari, Esmaeil; Ball, Andrew S.; Tibbett, Mark; Ryan, Megan H.

    2016-09-01

    Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. To test their potential implication for bioremediation, we applied two commonly exuded carboxylates (citrate and malonate) to uncontaminated and diesel-contaminated microcosms (10 000 mg kg-1; aged 40 days) and determined their impact on the microbial community and PHC degradation. Every 48 h for 18 days, soil received 5 µmol g-1 of (i) citrate, (ii) malonate, (iii) citrate + malonate or (iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by a community-level physiological profile (CLPP) and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis (DGGE). Saturated PHCs remaining in the soil were assessed by gas chromatography-mass spectrometry (GC-MS). Cumulative soil respiration increased 4- to 6-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community in both contaminated and uncontaminated soils but only a small increase in the biodegradation of saturated PHCs as measured by the n-C17 : pristane biomarker. We conclude that while the addition of citrate and malonate had little direct effect on the biodegradation of saturated hydrocarbons present in diesel, their effect on the microbial community leads us to suggest further studies using a variety of soils and organic acids, and linked to in situ studies of plants, to investigate the role of carboxylates in microbial community dynamics.

  8. Resíduos orgânicos como recondicionante de subsolo degradado e efeitos na atividade microbiana e fertilidade em cultivo de barbatimão Organic residues used as degraded subsoil reconditioner nd their effect on soil microbial activity and soil fertility in barbatimão cultivation

    Directory of Open Access Journals (Sweden)

    Hemerson Fernandes Calgaro

    2008-12-01

    as a reconditioner of degraded subsoil and quantify its effects on soil microbial activity and fertility in 'barbatimão' (Stryphnodendron polyphyllum Mart. cultivation. The area is located at the UNESP/ Ilha Solteira Campus farm, in Selvíria - MS. Four sections (repetitions of 250 m² (10 x 25 m were allocated, with 10 treatments for each, as follows: control; liming; fertilizing+N+P; liming+N+P; N+P+water hyacinth; N+P+sugar cane bagasse; N+P+water hyacinth+sugar cane bagasse; liming+N+P+water hyacinth; liming+N+P+sugar cane bagasse and liming+N+P+water hyacinth+sugar cane bagasse. The chemical characteristics of the subsoil were evaluated as well as plant growth, carbon microbial biomass (CMB and released c-CO2 , metabolic quotient (qCO2 and microbial quotient (qMIC, in 5 subsoil sample collecting times (June, August, November and December, 2005 and March, 2006. The subsoil displayed the same acid and poor nutrient level characteristics after a year. During the experiment, the CMB presented stabilization tendencies and the qCO2 and qMIC decreased in the same period. In all, even below the ideal level, the organic residues showed better results, with small positive differences for water hyacinth. CMB exhibited seasonal variations.

  9. High Pressure Preignition Chemistry of Hydrocarbons and Hydrocarbon Mixtures

    Science.gov (United States)

    2007-11-02

    and hydrocarbon blends in our various combustion systems, with emphasis on the effects of elevated pressure using our pressurized flow reactor ( PFR ...facility. Detailed experimental data were generated from the PFR for use in associated kinetic modeling work. We continued to develop and extend both

  10. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August ...

  11. Do mature hydrocarbons have an influence on acid rock drainage generation?

    OpenAIRE

    Jiménez-Castañeda, Martha E.; Boothman, Christopher; Lloyd, Jonathan R.; Vaughan, David J; van Dongen, Bart E.

    2016-01-01

    The generation of acid rock drainage (ARD) is a biogeochemical process that causes severe ecological impacts, threatening human health worldwide. Microbes involved in acid drainage reactions are generally considered autotrophic but heterotrophic and mixotrophic microorganisms have often been identified at ARD sites. This raises questions about the role of organic matter naturally present at these sites, such as mature hydrocarbons, in promoting the microbial processes underpinning ARD generat...

  12. Formation of hydrocarbons by micro-organisms. [Review with 152 references

    Energy Technology Data Exchange (ETDEWEB)

    Bird, C.W. (Queen Elizabeth Coll., London); Lynch, J.M.

    1974-01-01

    A review covers the formation of methane, e.g., by Methanobacterium ruminantium on hydrogen and carbon dioxide substrate in swamps, sewage plants, etc.; ethylene, e.g., from plant pathogens such as Penicillium digitatum in citrus fruits; other short-chain hydrocarbons, e.g., hexa-1,3,5-triyne, formed by the fungus Fomes annosus; longer-chain hydrocarbons, e.g., C/sub 16/-C/sub 33/ alkanes formed by algae and fungi, with the chain lengths dependent upon the carbon source used for growth; isoprenoid hydrocarbons, e.g., squalene, formed by yeasts and fungi; and geochemical aspects, such as the microbial contributions to petroleum formation. 152 references.

  13. [Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

    Science.gov (United States)

    Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

    2008-12-01

    A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results