خيارات البحث
النتائج 121 - 130 من 5,098
Biological impacts of local vs. regional land use on a small tributary of the Seine River (France): insights from a food web approach based on stable isotopes
2018
Hette-Tronquart, N. | Oberdorff, T. | Tales, E. | Zahm, Amandine | Belliard, J. | Hydrosystèmes et Bioprocédés (UR HBAN) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE [ADD1_IRSTEA]Dynamique et fonctionnement des écosystèmes | International audience | As part of the landscape, streams are influenced byland use. Here, we contributed to the understanding of the biological impacts of land use on streams, investigating how landscape effects vary with spatial scales (local vs. regional). We adopted a food web approach integrating both biological structure and functioning, to focus on the overall effect of land use on stream biocoenosis. We selected 17 sites of a small tributary of the Seine River (France) for their contrasted land use, and conducted a natural experiment by sampling three organic matter sources, three macroinvertebrate taxa, and most of the fish community. Using stable isotope analysis, we calculated three food web metrics evaluating two major dimensions of the trophic diversity displayed by the fish community: (i) the diversity of exploited resources and (ii) the trophic level richness. The idea was to examine whether (1) land-use effects varied according to spatial scales, (2) land use affected food webs through an effect on community structure and (3) land use affected food webs through an effect onavailable resources. Beside an increase in trophic diversity from upstream to downstream, our empirical data showed that food webs were influenced by land use in the riparian corridors (local scale). The effect was complex, and depended on site's position along the upstream-downstream gradient. By contrast, land use in the catchment (regional scale) did not influence stream biocoenosis. At the local scale, community structure was weakly influenced by land use, and thus played a minor role in explaining food web modifications. Our results suggested that the amount of available resources at the base of the food web was partly responsible for food web modifications. In addition, changes in biological functioning (i.e. feeding interactions) can also explain another part of the land-use effect. These results highlight the role played by the riparian corridors as a buffer zone, and advocate that riparian corridor should be at the centre of water management attention.
اظهر المزيد [+] اقل [-]Antifungal activity of essential oils on two Venturia inaequalis strains with different sensitivities to tebuconazole
2018
Muchembled, Jérôme | Deweer, Caroline | Sahmer, Karin | Halama, Patrice | Institut Charles Viollette (ICV) - ULR 7394 (ICV) ; Université d'Artois (UA)-Université du Littoral Côte d'Opale (ULCO)-Institut Supérieur d'Agriculture-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | SFR Condorcet ; Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire de Génie Civil et Géo-Environnement (LGCgE) - ULR 4515 (LGCgE) ; Université d'Artois (UA)-Université de Lille-Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai) ; Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-JUNIA (JUNIA) ; Université catholique de Lille (UCL)-Université catholique de Lille (UCL)
International audience | The antifungal activity of seven essential oils (eucalyptus, clove, mint, oregano, savory, tea tree, and thyme) was studied on Venturia inaequalis, the fungus responsible for apple scab. The composition of the essential oils was checked by gas chromatography-mass spectrometry. Each essential oil had its main compound. Liquid tests were performed to calculate the IC50 of essential oils as well as their majority compounds. The tests were made on two strains with different sensitivities to tebuconazole: S755, the sensitive strain, and rs552, the strain with reduced sensitivity. Copper sulfate was selected as the reference mineral fungicidal substance. IC50 with confidence intervals were calculated after three independent experiments. The results showed that all essential oils and all major compounds had in vitro antifungal activities. Moreover, it was highlighted that the effectiveness of four essential oils (clove, eucalyptus, mint, and savory) was higher than copper sulfate on both strains. For each strain, the best activity was obtained using clove and eucalyptus essential oils. For clove, the IC50 obtained on the sensitive strain (5.2 mg/L [4.0–6.7 mg/L]) was statistically lower than the IC50 of reduced sensitivity strain (14 mg/L [11.1–17.5 mg/L]). In contrast, for eucalyptus essential oil, the IC50 were not different with respectively 9.4–13.0 and 12.2–17.9 mg/L for S755 and rs552 strains. For mint, origano, savory, tea tree, and thyme, IC50 were always the best on rs552 strain. The majority compounds were not necessarily more efficient than their corresponding oils; only eugenol (for clove) and carvacrol (for oregano and savory) seemed to be more effective on S755 strain. On the other hand, rs552 strain seemed to be more sensitive to essential oils than S755 strain. In overall, it was shown that essential oils have different antifungal activities but do not have the same antifungal activities depending on the fungus strain used.
اظهر المزيد [+] اقل [-]Life cycle assessment of a bioelectrochemical system as a new technological platform for biosuccinic acid production from waste | Analyse du cycle de vie d'un système bioélectrochimique en tant que plate-forme technologique innovante pour la production d'acide succinique à partir de déchets
2018
Foulet, A. | Bouchez, T. | Desmond Le Quéméner, E. | Giard, L. | Renvoisé, L. | Aissani, A. | Optimisation des procédés en Agriculture, Agroalimentaire et Environnement (UR OPAALE) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Hydrosystèmes et Bioprocédés (UR HBAN) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE) ; Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro) | SUEZ ENVIRONNEMENT (FRANCE) | BIORARE project (ANR-10-BTBR-02) | ANR-10-BTBR-0002,BIORARE,BIOelectrosynthèse pour le Raffinage des déchets Residuels(2010)
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [ADD1_IRSTEA]Valoriser les effluents et déchets organiques | International audience | Waste management is a key environmental and socio-economic issue. Environmental concerns are encouraging the use of alternative resources and lower emissions to air, water and soil. Innovative technologies to deal with waste recovery that produce marketable bioproducts are emerging. Bioelectrochemical synthesis systems (BESs) are based on the primary principle of transforming organic waste into added-value products using microorganisms to catalyse chemical reactions. This technology is at the core of a research project called BIORARE (BIoelectrosynthesis for ORganic wAste bioREfinery), an interdisciplinary project that aims to use anaerobic digestion as a supply chain to feed a BES and produce target biomolecules. This technology needs to be driven by environmental strategies. Life Cycle Assessment (LCA) was used to evaluate the BIORARE concept based on expert opinion and prior experiments for the production of biosuccinic acid and waste management. A multidisciplinary approach based on biochemistry and process engineering expertise was used to collect the inventory data. The BES design and the two-step anaerobic digestion process have many potential impacts on air pollution or ecotoxicity-related categories. The comparison of the BIORARE concept with conventional fermentation processes and a water-fed BES technology demonstrated the environmental benefit resulting from the use of both the BES technology and a waste-based substrate as input thus supporting the BIORARE concept. Some trade-offs among the impact categories were identified but led to options to improve the concept. BES design and synergy management may improve the environmental performance of the BIORARE concept
اظهر المزيد [+] اقل [-]Large-scale geographic patterns of mercury contamination in Morocco revealed by freshwater turtles
2018
Slimani, Tahar | El Hassani, Mohamed Said | El Mouden, El Hassan | Bonnet, Marine | Bustamante, Paco | Brischoux, Francois | Brault-Favrou, Maud | Bonnet, Xavier | Faculté des Sciences Semlalia [Marrakech] ; Université Cadi Ayyad [Marrakech] (UCA) | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | LIttoral ENvironnement et Sociétés (LIENSs) ; La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
International audience | Mercury (Hg) is a toxic contaminant present in most aquatic ecosystems. High concentrations pose serious threats to organisms and to human health. Because previous studies focused on few countries, environmental hazard due to Hg contamination remains obscure in many geographic areas, and for example limited information is available in North Africa. We examined total Hg contamination in 13 sites in Morocco (12 rivers and one lake) spread over a large area, 400 km north–south and 350 km west–east, that encompasses different biogeographic zones separated by the Atlas Mountains. Due to their longevity and sedentary habits, we used freshwater turtles as biological probes to monitor Hg exposure. Keratinized tissues reflect long-term Hg exposure; thus, we assayed Hg concentration in the claws of > 200 individuals and supplemented these data with blood Hg concentrations of > 60 individuals (a tissue that provides shorter term Hg exposure integration). The results provide the first large-scale picture of Hg contamination in the aquatic freshwater systems of Morocco. Comparisons with previous studies revealed that some of the sites were highly contaminated (e.g. mean Hg concentrations were above 5 μg g⁻¹, a very high level in keratinized tissues) whereas other sites presented moderate or baseline levels. Unexpectedly, all highly contaminated sites were found in less densely populated areas, while more densely urbanized northern sites, even the sewers of large cities, were not highly contaminated. We hypothesize that silver mining activities in the southern High Atlas and in the Anti-Atlas contaminate rivers of the catchment basins over long distances. These findings indicate that fish, water consumption and contamination levels in local people should be further scrutinized.
اظهر المزيد [+] اقل [-]Chemistry, activity, and impact of plant biocontrol products
2018
Bertrand, Cédric | Prigent-Combaret, Claire | Gonzales-Coloma, Azucena | Centre de recherches insulaires et observatoire de l'environnement (CRIOBE) ; Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM) ; Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)
International audience
اظهر المزيد [+] اقل [-]Incidence of hydrological, chemical, and physical constraints on bacterial pathogens, Nocardia cells, and fecal indicator bacteria trapped in an urban stormwater detention basin in Chassieu, France
2018
Bernardin-Souibgui, Claire | Barraud, Sylvie | Bourgeois, Emilie | Aubin, Jean-Baptiste | Becouze-Lareure, Céline | Wiest, Laure | Marjolet, Laurence | Colinon, Céline | Lipeme Kouyi, Ghislain | Cournoyer, Benoit | Blaha, Didier | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM) ; Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS) | Déchets Eaux Environnement Pollutions (DEEP) ; Institut National des Sciences Appliquées de Lyon (INSA Lyon) ; Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA) | ISA-TRACES - Technologie et Recherche en Analyse Chimique pour l'Environnement et la Santé ; Institut des Sciences Analytiques (ISA) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Labex IMU (Project IMU-MIC); Labex IMU (Project IMU-Patho-Air); PEPS-CNRS (Patho-BRD); ANR CABRRES; Grand Lyon Metropolis; Rhone-Mediterranean-Corsica Water Agency | ANR-11-CESA-0012,CABRRES,CAractérisation chimique, microbiologique, écotoxicologique et spatio-temporelle des contaminants des Bassins de Retenue des eaux pluviales urbaines : évaluation et gestion des Risques Environnementaux et Sanitaires associés(2011)
International audience | The nature and fate of urban contaminants washed by stormwater events and accumulating in a detention basin (DB) were investigated. Relations between bacterial and chemical contaminants of trapped urban sediments, and field parameters were analyzed. Fecal indicators and some pathogens known to be environmentally transmitted (Nocardia, Pseudomonas aeruginosa, and Aeromonas caviae) were tracked, and their persistence investigated. Six sampling campaigns were carried out over 3 years, using five sites including a settling chamber (SC). Aerosolized bacteria at these sites were also monitored. Deposits in the basin were made of fine particles and their content in chemical pollutants was found highly variable. High polycyclic aromatic hydrocarbon (PAH) contents were measured but only three pesticides, over 22, were detected. Deposits were significantly contaminated by fecal indicator bacteria (FIB), P. aeruginosa, A. caviae, and by Nocardia. Only A. caviae showed significant numbers in aerosolized particles recovered over the detention basin. Nocardia spp. cells heavily contaminated the SC. The efficacy of the detention basin at reducing bacterial counts per rain event and over time were estimated. A slight drop in the counts was monitored for fecal indicators but not for the other bacterial groups. Hydrodynamic parameters had a strong impact on the distribution and features of the deposits. Multiple factors impacted the fate of FIB, P. aeruginosa, A. caviae, and Nocardia cells, but in a group dependent manner. Nocardia counts were found positively correlated with volatile organic matter. FIB appeared highly efficient colonizers of the DB.
اظهر المزيد [+] اقل [-]How to assess the feeding activity in ecotoxicological laboratory tests using enchytraeids?
2018
Bart, Sylvain | Roudine, Sacha | Amossé, Joël | Mougin, Christian | Pery, Alexandre R.R. | Pelosi, Céline | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Université Paris-Saclay
The risk assessment of pesticides on soil fauna is an issue to protect agroecosystem sustainability. Enchytraeids are recognized as relevant soil bioindicators of chemical stress in agroecosystems. In laboratory, the reproduction test was found to be sensitive to reveal chemical impacts on enchytraeids. However, it does not allow to assess the impacts on ecological functions in which enchytraeids are involved. The objectives of this study were (i) to explore the feasibility of the bait-lamina test with enchytraeids under laboratory conditions and (ii) to compare its sensitivity with the Enchytraeid Reproduction Test. We exposed individuals of Enchytraeus albidus to two commercial formulations of fungicides widely used in Europe. The EC50 reproduction for the Swing® Gold (50 g L−1 epoxiconazole and 133 g L−1 dimoxystrobin) and the Cuprafor micro® (50% copper oxychloride) were respectively estimated at 1.66 ± 0.93 times the recommended dose and > 496 mg kg−1 of copper. However, no impact was found on the feeding activity of enchytraeids. The bait-lamina test thus appeared less sensitive than the Enchytraeid Reproduction Test to the tested fungicides. Despite that, this test which is achievable under laboratory conditions and allows assessing indirect effects of pesticides is quick, cheap, and easy to perform. It would deserve to be used to explore longer-exposure effects through the repeated addition of bait-lamina sticks.
اظهر المزيد [+] اقل [-]Successful Biodegradation of a Refractory Pharmaceutical Compound by an Indigenous Phenol-Tolerant Pseudomonas aeruginosa Strain
2018
Hemidouche, Sabra | Favier, Lidia | Amrane, Abdeltif | Dabert, Patrick | Le Roux, Sophie | Sadaoui, Zahra | Laboratoire de Génie de la Réaction ; Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB) | Institut des Sciences Chimiques de Rennes (ISCR) ; Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes) ; Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Optimisation des procédés en Agriculture, Agroalimentaire et Environnement (UR OPAALE) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [ADD1_IRSTEA]Valoriser les effluents et déchets organiques | International audience | This study provides an alternative solution for the bioremediation of a recalcitrant pharmaceutical micropollutant. Clofibric acid (CLA) was chosen as target molecule, because of its environmental persistence and resistance to wastewater treatment technologies. The aim of this study was to investigate the potential of a phenol-resistant Pseudomonas aeruginosa strain isolated from the activated sludge to degrade CLA. In order to evaluate the effect of acclimation process with glucose as carbon co-substrate, two protocols were performed, in which the transfer of the inoculum is carried out either in the exponential growth phase or in the decline phase. The results showed a removal efficiency of CLA of 35% when cells in the decline phase were used for inoculation. In contrast, a very low removal yield (10%) was achieved when cells harvested in the exponential phase were used as inoculum. This work is the first one reporting on the capability of this bacterium to remove this drug. The obtained data showed that the isolated strain is able to degrade target molecule and might be a promising agent for the elimination of this refractory compound.
اظهر المزيد [+] اقل [-]Seasonal variations of contamination and exoskeletal malformations in the white shrimps Palaemon longirostris in the Gironde estuary, France
2018
Lévesque, B. | Cachot, J. | Boët, Philippe | Lepage, Mario | Mazzella, Nicolas | Martin, C. | Gourves, P.Y. | Legeay, A. | Ecosystèmes aquatiques et changements globaux (UR EABX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Environnements et Paléoenvironnements OCéaniques (EPOC) ; Observatoire aquitain des sciences de l'univers (OASU) ; Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
[Departement_IRSTEA]Eaux [ADD1_IRSTEA]Dynamique et fonctionnement des écosystèmes | International audience | Since the end of the 1980s, white shrimps (Palaemon longirostris) from the Gironde estuary have exhibited exoskeletal malformations, mainly involving cephalothorax, rostrum, scaphocerites and uropods. An 8-month study was carried out in 2015. Each month, 200 individuals were sampled and examined for exoskeletal malformations. Temporal variations in malformationfrequency were noted,particularlyduringthebreedingperiod, along withdecreases in the sizeof non-deformedshrimps related to the appearance of juveniles in breeding sites, and high mortality among deformed shrimps. A significant increase in proportions of deformed shrimp was observed, relating particularly to the size (and therefore the age) of individuals. No significant difference was found between shrimp proportions with different numbers of malformations (one to four) for a fixed size class, nor was there any variation in proportions within different size classes for a fixed number of malformations. This would appear toindicate thatthe number ofmalformations isacquiredand new malformations donot seemto appearduringthe lifecycle,exceptforthesmallest(youngest)shrimps.Themalformationspectrumshowednosignificantdifferencesbetweenthe biggest and smallest individuals for the different malformation associations, except for those involving cephalothorax, rostrum and uropods. This would suggest that some malformation associations lead to a higher mortality rate in shrimps subjected to them, due to greater impairment of feeding and/or swimming behaviour. Multiple component analysis of the different types of malformation showed correlations between exoskeletal pieces (rostrum and cephalothorax) and appendixes (scaphocerites and uropods). Regarding metal contamination in shrimp, no significant difference was highlighted between deformed and nondeformed shrimps. Organic pollutants were not measured in tissues. Certain herbicides such as metolachlore and chlortoluron.
اظهر المزيد [+] اقل [-]Pesticide residue profiles in bee bread and pollen samples and the survival of honeybee colonies: a case study from Luxembourg
2018
Beyer, M. | Lenouvel, A. | Guignard, C. | Eickermann, M. | Clermont, Antoine | Kraus, F. | Hoffmann, - | ENVIRONMENTAL RESEARCH AND INNOVATION DEPARTMENT LUX ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro) | ADMINISTRATION DES SERVICES TECHNIQUES DE L'AGRICULTURE LUXEMBOURG LUX ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE [ADD1_IRSTEA]Équiper l'agriculture | International audience | Pesticide residues (112 compounds) were quantified by GC-MS/MS or LC-MS/MS in 85 bee bread samples and 154 pollen samples obtained from five apiaries each with three or four colonies (genotype Buckfast) in Luxembourg over the period 2011-2013. Thiacloprid, chlorfenvinphos, tebuconazole, and methiocarb were found most frequently in bee bread while thiacloprid, permethrin-cis, and permethrin-trans were detected most frequently in the pollen samples. Three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) that were restricted by an EU regulation in 2013 after our sampling campaign was finished were each found in less than 8% of the pollen or bee bread samples. The maximum concentrations of thiacloprid, metazachlor, and methiocarb measured in the pollen collected by a group of honeybee colonies (n=5) without survivors within the 3-year period of observation were 86.20 +/- 10.74ng/g, 2.80 +/- 1.26ng/g, and below the limit of quantification, respectively. The maximum concentrations of the same compounds measured in the pollen collected by a group of honeybee colonies with significantly (P=0.02) more survivors (7 out of 9) than expected, if the survivors had been distributed randomly among the groups of colonies, were 11.98 +/- 2.28ng/g, 0.44 +/- 0.29ng/g, and 8.49 +/- 4.13ng/g, respectively. No honeybee colony that gathered pollen containing more than 23ng/g thiacloprid survived the 3-year project period. There was no statistically significant association between pesticide residues in the bee bread and the survival of the colonies. Actions already taken or planned and potential further actions to protect bees from exposure to pesticides are discussed.
اظهر المزيد [+] اقل [-]