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An urban boreal lake basin as a source of CO₂ and CH₄ Full text
2011
López Bellido, Jessica | Peltomaa, Elina | Ojala, Anne
Up to now, carbon gas fluxes from urban lakes in the boreal zone have seldom been studied. In summer 2005 we investigated fluxes from an urban boreal lake basin in southern Finland with long history of eutrophication and anoxia. Hypolimnetic CO₂ and CH₄ concentrations were high compared to other boreal lakes. During the open-water period, the lake basin acted as a source of CO₂ and CH₄ with fluxes of 2.10 mol m⁻² and 0.04 mol m⁻², respectively. Despite the high oxidation rate (83%), CH₄ flux was higher than in other lakes and CH₄ contributed 60% to Global Warming Potential. The ratio of carbon emission to accumulation was 4, i.e. emissions were an important route for carbon departure but less so than in rural lakes. Since the lake oxygen conditions affected nutrient availability, there was a positive feedback from hypolimnion to carbon uptake, which was reflected in gas concentrations.
Show more [+] Less [-]Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal Full text
2011
Arao, Tomohito | Maejima, Yuji | Baba, Koji
Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean.
Show more [+] Less [-]Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Bérard, Annette
Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Bérard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.
Show more [+] Less [-]Use of the MicroResp method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette, A. | Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819) ; Institut Nanosciences et Cryogénie (INAC) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) ; Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Laboratoire d'Ecologie Alpine (LECA) ; Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS) | Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | A modified MicroRespÔ technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community. a b s t r a c t Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRespÔ technique, in a pollution-induced community tolerance approach. The results show that MicroRespÔ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRespÔ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.
Show more [+] Less [-]Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili , Ahmed (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Maréchal , Marjorie (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Montuelle , Bernard (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Volat , Bernadette (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Dorigo , Ursula (INRA , Thonon-Les-Bains (France). UMR 0042 Centre Alpin de Recherche sur les Réseaux Trophiques des Ecosystèmes limniques) | Berard , Annette (INRA , Avignon (France). UMR 1114 Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes )
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroResp™ technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community
Show more [+] Less [-]Use of the MicroResp (TM) method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Maréchal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRes (TM) technique, in a pollution-induced community tolerance approach. The results show that MicroRes (TM) can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRes (TM) was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroRes (TM) technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community.
Show more [+] Less [-]Use of the MicroResp (TM) method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Maréchal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRes (TM) technique, in a pollution-induced community tolerance approach. The results show that MicroRes (TM) can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRes (TM) was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroRes (TM) technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community.
Show more [+] Less [-]Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, Jose L. | Collins, Chris D. | Hodson, Mark E.
Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, Jose L. | Collins, Chris D. | Hodson, Mark E.
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability.
Show more [+] Less [-]Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, J L | Collins, Christopher David | Hodson, Mark Edward
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability.
Show more [+] Less [-]Arsenic distribution in soils and plants of an arsenic impacted former mining area Full text
2011
Otones, V. | Álvarez-Ayuso, E. | García-Sánchez, A. | Santa Regina, I. | Murciego, A.
A mining area affected by the abandoned exploitation of an arsenical tungsten deposit was studied in order to assess its arsenic pollution level and the feasibility of native plants for being used in phytoremediation approaches. Soil and plant samples were collected at different distances from the polluting sources and analysed for their As content and distribution. Critical soil total concentrations of As were found, with values in the range 70–5330mgkg⁻¹ in the uppermost layer. The plant community develops As tolerance by exclusion strategies. Of the plant species growing in the most polluted site, the shrubs Salix atrocinerea Brot. and Genista scorpius (L.) DC. exhibit the lowest bioaccumulation factor (BF) values for their aerial parts, suggesting their suitability to be used with revegetation purposes. The species Scirpus holoschoenus L. highlights for its important potential to stabilise As at root level, accumulating As contents up to 3164mgkg⁻¹.
Show more [+] Less [-]Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains Full text
2011
Yousaf, Sohail | Afzal, Muhammad | Reichenauer, Thomas G. | Brady, Carrie L. | Sessitsch, Angela
Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains Full text
2011
Yousaf, Sohail | Afzal, Muhammad | Reichenauer, Thomas G. | Brady, Carrie L. | Sessitsch, Angela
The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants.
Show more [+] Less [-]Relationship between ²¹⁰Pbₑₓ activity and sedimentary organic carbon in sediments of 3 Chinese lakes Full text
2011
Xu, Libin | Wu, Fengchang | Wan, Guojiang | Liao, Haiqing | Zhao, Xiaoli | Xing, Baoshan
This report demonstrates that organic matter was an important factor in lake sediment ²¹⁰Pbₑₓ dating. Sediment cores from lakes in central and western China with different-trophic levels were collected, and the ²¹⁰Pbₑₓ activity and total organic carbon (TOC) were measured. The Rock-Eval pyrolysis technique was used to deconvolute TOC into free hydrocarbons (S1), thermally less-stable macromolecular organic matter (S2a), kerogen (S2b), and residual carbon (RC). The results show significant correlations between TOC and ²¹⁰Pbₑₓ, particularly between S2a and ²¹⁰Pbₑₓ, in all the sediment cores. This indicated that the algal-derived organic component S2a may play the most important role in controlling the distribution of ²¹⁰Pbₑₓ. Scavenging by algal-derived organic matter may be the main mechanism. As chronology is the key to the understanding of pollution reconstruction and early diagenesis in sediments, more attention should be paid to the influence of organic matter on ²¹⁰Pbₑₓ.
Show more [+] Less [-]Behavior of decabromodiphenyl ether (BDE-209) in soil: Effects of rhizosphere and mycorrhizal colonization of ryegrass roots Full text
2011
Wang, Sen | Zhang, Shuzhen | Huang, Honglin | Christie, Peter
A rhizobox experiment was conducted to investigate degradation of decabromodiphenyl ether (BDE-209) in the rhizosphere of ryegrass and the influence of root colonization with an arbuscular mycorrhizal (AM) fungus. BDE-209 dissipation in soil varied with its proximity to the roots and was enhanced by AM inoculation. A negative correlation (P < 0.001, R² = 0.66) was found between the residual BDE-209 concentration in soil and soil microbial biomass estimated as the total phospholipid fatty acids, suggesting a contribution of microbial degradation to BDE-209 dissipation. Twelve and twenty-four lower brominated PBDEs were detected in soil and plant samples, respectively, with a higher proportion of di- through hepta-BDE congeners in the plant tissues than in the soils, indicating the occurrence of BDE-209 debromination in the soil-plant system. AM inoculation increased the levels of lower brominated PBDEs in ryegrass. These results provide important information about the behavior of BDE-209 in the soil-plant system.
Show more [+] Less [-]Products and stability of phosphate reactions with lead under freeze–thaw cycling in simple systems Full text
2011
Hafsteinsdóttir, Erla G. | White, D. A. (Duanne A.) | Gore, Damian B. | Stark, Scott C.
Orthophosphate fixation of metal contaminated soils in environments that undergo freeze–thaw cycles is understudied. Freeze–thaw cycling potentially influences the reaction rate, mineral chemical stability and physical breakdown of particles during fixation. This study determines what products form when phosphate (triple superphosphate [Ca(H₂PO₄)₂] or sodium phosphate [Na₃PO₄]) reacts with lead (PbSO₄ or PbCl₂) in simple chemical systems in vitro, and assesses potential changes in formation during freeze–thaw cycles. Systems were subjected to multiple freeze–thaw cycles from +10 °C to −20 °C and then analysed by X-ray diffractometry. Pyromorphite formed in all systems and was stable over multiple freeze–thaw cycles. Low temperature lead orthophosphate reaction efficiency varied according to both phosphate and lead source; the most time-efficient pyromorphite formation was observed when PbSO₄ and Na₃PO₄ were present together. These findings have implications for the manner in which metal contaminated materials in freezing ground can be treated with phosphate.
Show more [+] Less [-]A rapid and high-throughput quantum dots bioassay for monitoring of perfluorooctane sulfonate in environmental water samples Full text
2011
Zhang, Jiong | Wan, Yanjian | Li, Yuanyuan | Zhang, Qiongfang | Xu, Shunqing | Zhu, Huijun | Shu, Baihua
Currently HPLC/MS is the state of the art tool for environmental/drinking water perfluorooctane sulfonate (PFOS) monitoring. PFOS can bind to peroxisomal proliferator-activated receptor-alpha (PPARα), which forms heterodimers with retinoid X receptors (RXRs) and binds to PPAR response elements. In this bioassay free PFOS in water samples competes with immobilized PFOS in ELISA plates for a given amount of PPARα–RXRα. It can be determined indirectly by immobilizing PPARα–RXRα–PFOS complex to another plate coated with PPARα antibody and subsequent measuring the level of PPARα–RXRα by using biotin-modified PPARα–RXRα probes–quantum dots–streptavidin detection system. The rapid and high-throughput bioassay demonstrated a detection limit of 2.5 ng L⁻¹ with linear range between 2.5 ng L⁻¹ and 75 ng L⁻¹. Detection results of environmental water samples were highly consistent between the bioassay and HPLC/MS.
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