Refinar búsqueda
Resultados 1681-1690 de 3,208
Genetic diversity of three classes of integrons in antibiotic-resistant bacteria isolated from Jiulong River in southern China Texto completo
2015
Lin, Mao | Liang, Jingjing | Zhang, Xian | Wu, Xiaomei | Yan, Qingpi | Luo, Zhuanxi
We identified antibiotic-resistant bacterial isolates from the surface waters of Jiulong River basin in southern China and determined their extent of resistance, as well as the prevalence and characterization of three classes of integrons. A phylogenetic analysis of 16S ribosomal DNA (rDNA) sequences showed that 20 genera were sampled from a total of 191 strains and the most common genus was Acinetobacter. Antimicrobial susceptibility testing revealed that the 191 isolates were all multiresistant and there were high levels of resistance to 19 antimicrobials that were tested, particularly the β-lactam, sulfonamide, amphenicol, macrolide, and rifamycin classes. Moreover, class 1 integrons were ubiquitous while only five out of 191 strains harbored class 2 integrons and no class 3 integrons were detected. The variable region of the class 1 integrons contained 30 different gene cassette arrays. Nine novel arrays were found in 65 strains, and seven strains had empty integrons. Among these 30 arrays, there were 34 different gene cassettes that included 25 resistance genes, six genes with unknown functions, two mutant transposase genes, and a new gene. The unique array dfrA1-sat2-aadA1 was detected in all five isolates carrying the class 2 integron. We found that antibiotic-resistant bacterial isolates from Jiulong River were diverse and antibiotic resistance genes associated with integrons were widespread.
Mostrar más [+] Menos [-]A coordinated set of ecosystem research platforms open to international research in ecotoxicology, AnaEE-France Texto completo
2015
Mougin, Christian | Azam, Didier | Caquet, Thierry | Cheviron, Nathalie | Dequiedt, Samuel | Le Galliard, Jean-François | Guillaume, Olivier | Houot, Sabine | Lacroix, Gerard | Lafolie, François | Maron, Pierre-Alain | Michniewicz, Radika | Pichot, Christian | Ranjard, Lionel | Roy, Jacques | Zeller, Bernd | Clobert, Jean | Chanzy, André
A coordinated set of ecosystem research platforms open to international research in ecotoxicology, AnaEE-France Texto completo
2015
Mougin, Christian | Azam, Didier | Caquet, Thierry | Cheviron, Nathalie | Dequiedt, Samuel | Le Galliard, Jean-François | Guillaume, Olivier | Houot, Sabine | Lacroix, Gerard | Lafolie, François | Maron, Pierre-Alain | Michniewicz, Radika | Pichot, Christian | Ranjard, Lionel | Roy, Jacques | Zeller, Bernd | Clobert, Jean | Chanzy, André
The infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical, and modeling platforms dedicated to the biological study of continental ecosystems (aquatic and terrestrial). This infrastructure aims at understanding and predicting ecosystem dynamics under global change. AnaEE-France comprises complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, seminatural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large-scale and long-term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro) biology. Finally, AnaEE-France provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical, and evolutionary approaches. In particular, AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure, and it is pioneering the construction of AnaEE (Europe) infrastructure in the field of ecosystem research. AnaEE-France infrastructure is already open to the international community of scientists in the field of continental ecotoxicology.
Mostrar más [+] Menos [-]A coordinated set of ecosystem research platforms open to international research in ecotoxicology, AnaEE-France Texto completo
2015
Mougin, Christian | Azam, Didier | Caquet, Thierry | Cheviron, Nathalie | Dequiedt, Samuel | Le Galliard, Jean-François | Guillaume, Olivier | Houot, Sabine | Lacroix, Gérard | Lafolie, Francois | Maron, Pierre-Alain | Michniewicz, Radika | Pichot, Christian | Ranjard, Lionel | Roy, Jacques | Zeller, Bernhard | Clobert, Jean | Chanzy, Andre | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Université Paris Saclay (COmUE) | Plateforme BIOCHEM-ENV ; Institut National de la Recherche Agronomique (INRA) | Unité d'Ecologie et Ecotoxicologie Aquatiques (UEEA) ; Institut National de la Recherche Agronomique (INRA) | Département Ecologie des Forêts, Prairies et milieux Aquatiques (DEPT EFPA) ; Institut National de la Recherche Agronomique (INRA) | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | Institut d'écologie et des sciences de l'environnement de Paris (iEES) ; Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS) | CEREEP-Ecotron Ile de France (UMS 3194) ; Département de Biologie - ENS-PSL (IBENS) ; École normale supérieure - Paris (ENS-PSL) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) | Station d’Ecologie Expérimentale du CNRS à Moulis (SEEM) ; Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-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) | Ecologie des Forêts Méditerranéennes (URFM) ; Institut National de la Recherche Agronomique (INRA) | Centre National de la Recherche Scientifique (CNRS) | Unité de recherche Biogéochimie des Ecosystèmes Forestiers (BEF) ; Institut National de la Recherche Agronomique (INRA) | ANR-10-EQPX-0013,PLANAQUA,PLAteforme expérimentale NAtionale d'écologie aQUAtique(2010) | ANR-11-INBS-0001,ANAEE-FR,ANAEE-Services(2011)
International audience | The infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical, and modeling platforms dedicated to the biological study of continental ecosystems (aquatic and terrestrial). This infrastructure aims at understanding and predicting ecosystem dynamics under global change. AnaEE-France comprises complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, seminatural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large-scale and long term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro) biology. Finally, AnaEEFrance provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical, and evolutionary approaches. In particular, AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure, and it is pioneering the construction of AnaEE (Europe) infrastructure in the field of ecosystem research. AnaEE-France infrastructure is already open to the international community of scientists in the field of continental ecotoxicology.
Mostrar más [+] Menos [-]A coordinated set of ecosystem research platforms open to international research in ecotoxicology, AnaEE-France Texto completo
2016
Mougin, Christian | Azam, Didier | Caquet, Thierry | Cheviron, Nathalie | Dequiedt, Samuel | Le Gaillard, Jean-François | Guillaume, Olivier | Houot, Sabine | Lacroix, Gérard | Lafolie, Francois | Maron, Pierre-Alain | Michniewicz, Radika | Pichot, Christian | Ranjard, Lionel | Roy, Jacques | Zeller, Bernd | Clobert, Jean | Chanzy, Andre
Human activities have altered continental ecosystems worldwide and generated a major environmental crisis. To truly develop integrative ecosystem biology and to assess the consequences of various forcing factors, such as pollutions, we therefore need new approaches and tools that bridge the traditional gap between life and environmental sciences. To deal with that challenge, the infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical and modeling platforms dedicated to the biological study of continental ecosystems, both aquatic and terrestrial. This infrastructure aims at understanding and predicting ecosystem dynamics under global change. It comprises five complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, semi-natural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large scale and long-term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro)-biology. Finally, AnaEE-France provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical and evolutionary approaches. AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure and it is pioneering the construction of a European AnaEE infrastructure in the field of ecosystem research. This infrastructure is open to the international community of scientists in the field of continental ecotoxicology.
Mostrar más [+] Menos [-]Modeling of leachate recirculation using vertical wells in bioreactor landfills Texto completo
2015
Feng, Shi-Jin | Cao, Ben-Yi | Zhang, Xu | Xie, Hai-Jian
Leachate recirculation (LR) in municipal solid waste (MSW) landfills operated as bioreactors offers significant economic and environmental benefits. The subsurface application method of vertical wells is one of the most common LR techniques. The objective of this study was to develop a novel two-dimensional model of leachate recirculation using vertical wells. This novel method can describe leachate flow considering the effects of MSW settlement while also accounting separately for leachate flow in saturated and unsaturated zones. In this paper, a settlement model for MSW when considering the effects of compression and biodegradation on the MSW porosity was adopted. A numerical model was proposed using new governing equations for the saturated and unsaturated zones of a landfill. The following design parameters were evaluated by simulating the recirculated leachate volume and the influence zones of waste under steady-state flow conditions: (1) the effect of MSW settlement, (2) the effect of the initial void ratio, (3) the effect of the injected head, (4) the effect of the unit weight, (5) the effect of the biodegradation rate, and (6) the effect of the compression coefficient. The influence zones of LR when considering the effect of MSW settlement are smaller than those when neglecting the effect. The influence zones and LR volume increased with an increase in the injection pressure head and initial void ratio of MSW. The proposed method and the calculation results can provide important insight into the hydrological behavior of bioreactor landfills.
Mostrar más [+] Menos [-]Effects of added polyacrylamide on changes in water states during the composting of kitchen waste Texto completo
2015
Yang, Yu-Qiang | Chen, Zhuo-Xian | Zhang, Xue-Qing | Hu, Li-Fang | Shen, Dong-Sheng | Long, Yu-Yang
The effects of adding polyacrylamide (PAM), to attempt to delay the loss of capillary water and achieve a better level of organic matter humification, in the composting of kitchen waste were evaluated. Four treatments, with initial moisture content of 60 % were used: 0.1 % PAM added before the start of composting (R1), 0.1 % PAM added when the thermophilic phase of composting became stable (at >50 °C) (R2), 0.1 % PAM added when the moisture content significantly decreased (R3), and no PAM added (R4). The introduction of PAM in R1 and R2 significantly increased the capillary force and delayed the loss of moisture content and capillary water. The introduction of PAM in R2 and R3 improved the composting process, in terms of the degradation of biochemical fractions and the humification degree. These results show that the optimal time for adding PAM was the initial stage of the thermophilic phase.
Mostrar más [+] Menos [-]Determination of selected pharmaceuticals in tap water and drinking water treatment plant by high-performance liquid chromatography-triple quadrupole mass spectrometer in Beijing, China Texto completo
2015
Cai, Mei-Quan | Wang, Rong | Feng, Li | Zhang, Li-Qiu
A simultaneous determination method of 14 multi-class pharmaceuticals using solid-phase extraction (SPE) followed by high-performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS) was established to measure the occurrence and distribution of these pharmaceuticals in tap water and a drinking water treatment plant (DWTP) in Beijing, China. Target compounds included seven anti-inflammatory drugs, two antibacterial drugs, two lipid regulation drugs, one antiepileptic drug, and one hormone. Limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.01 to 1.80 ng/L and 0.05 to 3.00 ng/L, respectively. Intraday and inter-day precisions, recoveries of different matrices, and matrix effects were also investigated. Of the 14 pharmaceutical compounds selected, nine were identified in tap water of Beijing downtown with the concentration up to 38.24 ng/L (carbamazepine), and the concentration levels of detected pharmaceuticals in tap water (<5 ng/L for most pharmaceuticals) were lower than previous studies in other countries. In addition, ten and six pharmaceuticals were measured in raw water and finished water at the concentration ranged from 0.10 to 16.23 and 0.13 to 17.17 ng/L, respectively. Five compounds were detected most frequently in DWTP, namely antipyrine, carbamazepine, isopropylantipyrine, aminopyrine, and bezafibrate. Ibuprofen was found to be the highest concentration pharmaceutical during DWTP, up to 53.30 ng/L. DWTP shows a positive effect on the removal of most pharmaceuticals with 81.2–99.5 % removal efficiencies, followed by carbamazepine with 55.4 % removal efficiency, but it has no effect for removing ibuprofen and bezafibrate.
Mostrar más [+] Menos [-]The international environmental specimen banks—let’s get visible Texto completo
2015
Küster, Anette | Becker, Paul R. | Kucklick, John R. | Pugh, Rebecca S. | Koschorreck, Jan
Environmental specimen banks (ESBs) are facilities that archive samples from the environment for future research and monitoring purposes. In addition, the long-term preservation of representative specimens is an important complement to environmental research and monitoring. Today, environmental specimen banking is experiencing a renaissance due to an increase in regulatory interest in ESB biota standards and trend data. The International Environmental Specimen Bank Group (IESB) promotes the worldwide development of techniques and strategies of environmental specimen banking and the international cooperation and collaboration among national ESBs. In order to provide a current and comprehensive overview on international environmental specimen banking activities, a questionnaire was sent to the national ESBs and asked for detailed information on the respective ESBs. The results show the rich diversity of national sampling programs, including more detailed information on archived samples, sampling strategies, and studies that have already been performed in the respective countries. All ESBs completing the survey expressed a strong interest in cooperating with other ESBs on a collaborative project. The collected information of national ESBs is intended to be made publicly available.
Mostrar más [+] Menos [-]Toxicity bioassays for water from black-odor rivers in Wenzhou, China Texto completo
2015
DeFu, He | RuiRui, Chen | EnHui, Zhu | Na, Chen | Boyang, | HuaHong, Shi | MinSheng, Huang
Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed. As two typical black-odor rivers, Jiushanwai River (JS) and Shanxia River (SX) are tributaries of Wen-Rui Tang River in Wenzhou (south of China). The eco-safety of the urban rivers was evaluated by bioassay for water toxicity in this study. Ten and 5 sampling sites were respectively set along JS and SX. Water samples were collected monthly from October 2010 to October 2011. The general physical and chemical parameters of river water were monitored. In order to investigate the ecotoxicological effects of black-odor water, the following bioassays were used: (1) Fish acute toxicity test (Danio rerio, comprehensive toxicity), (2) luminescent bacteria bioassay (Qinghaiensis vibrio, toxicity to bacteria), and (3) tropical claw embryo assay (Xenopus tropicalis, embryo toxicity). Biotoxicity of black-odor rivers water was demonstrated by D. rerio, Q. vibrio, and X. tropicalis embryos. Toxicological effects of black-odor water were respectively shown by mortality of zebrafish, and by the relative inhibitory light rate of luminescent bacteria. However, luminescent bacteria were more sensitive to inspect biotoxicity than zebrafish. In X. tropicalis embryos test, toxicological effects of black-odor water were mostly shown by embryos’ survival rate and teratogenic rate. Bioassay results showed that toxicity of SX water was higher than that of JS water, especially in summer. Statistical analysis of luminescent bacteria toxicity test showed that biotoxicity of SX and JS was high in summer, but low in winter and spring. The seasonal changes of water toxicity of the black-odor river were positively correlative with changes of water temperature (p < 0.05), and related to pH and ammonium nitrogen of water. Typical black-odor river water displays different degrees of biotoxicity to D. rerio, luminescent bacteria, and X. tropicalis embryos. The ecotoxicological risk of black-odor rivers was demonstrated in urban area, which suggests bioassay is necessary for evaluation of water quality. In the present study, spatial and seasonal bioassay for toxicity of JS and SX provides a complete example for evaluation of urban rivers.
Mostrar más [+] Menos [-]Investigation of the interaction between As and Sb species and dissolved organic matter in the Yangtze Estuary, China, using excitation–emission matrices with parallel factor analysis Texto completo
2015
Wang, Ying | Zhang, Di | Shen, Zhen-yao | Feng, Cheng-hong | Zhang, Xiao
The interactions between trivalent or pentavalent As/Sb and dissolved organic matter (DOM) in four regions (the river channel, the adjacent coastal area, and the northern and southern nearshore areas) of the Yangtze Estuary, China, were studied using fluorescence quenching titration combined with excitation–emission matrix spectroscopy and parallel factor analysis (PARAFAC). The As/Sb–DOM complexation characteristics were investigated using FTIR and UV absorbance spectroscopy and zeta potential analysis. Four protein-like components and one humic-like component were identified in the DOM from the Yangtze Estuary, China, by PARAFAC analysis. The tryptophan-like substance represented by component 2 was the dominant component and played an important role in the complexation between DOM and As/Sb. The results of complexation modeling demonstrated that the binding capacity of trivalent As/Sb with DOM was higher than that of pentavalent As/Sb with DOM. The DOM from the north nearshore area with the most acidic functional groups and greatest aromaticity possessed the highest binding capacity for trivalent and pentavalent As/Sb. The increase in the UV absorbance and the charge neutralization further indicated the interaction between As/Sb and DOM. The higher binding capacity of Sb(III) with DOM was mainly due to the hydroxyl and carboxyl groups. Our study demonstrates that the use of the advanced EEM–PARAFAC method in fluorescence quenching studies is very useful for evaluating the properties of DOM–pollutant interactions.
Mostrar más [+] Menos [-]Three decades of environmental specimen banking at the National Institute for Environmental Studies, Japan Texto completo
2015
Karube, Zin-ichi | Tanaka, Atsushi | Takeuchi, Akinori | Takazawa, Yoshikatsu | Takagi, Mai | Kinoshita, Ayako | Seyama, Haruhiko | Shibata, Yasuyuki
After two decades operation of the initial environmental specimen banking, a new program, Environmental Time Capsule Program, started in 2002 as a government-supported long-term program to construct a firm scientific basis for various environmental research studies. The program consists of long-term environmental specimen banking activity and specimen collection of endangered wildlife and is based on cryogenic sample preservation facility called Environmental Time Capsule building, which completed construction in 2004. After 9 years of extensive research, research focuses have been selected and the program was reorganized to the environmental sample collection part and endangered wildlife collection part in 2011. Due to huge environmental disaster caused by the Great East Japan earthquake and the tsunami as well as subsequent nuclear power plant accident at Fukushima, a new sampling and monitoring program started at affected areas in collaboration with the reorganized environmental sample collection and archiving program. Outlines of the quality assurance and quality control (QA/QC) activities in the program and future perspective under related international activities, particularly Stockholm Convention, are reported.
Mostrar más [+] Menos [-]Antifungal efficiency of a lipopeptide biosurfactant derived from Bacillus subtilis SPB1 versus the phytopathogenic fungus, Fusarium solani Texto completo
2015
Mnif, Ines | Hammami, Ines | Triki, Mohamed Ali | Azabou, Manel Cheffi | Ellouze-Chaabouni, Semia | Ghribi, Dhouha
Bacillus subtilis SPB1 lipopeptides were evaluated as a natural antifungal agent against Fusarium solani infestation. In vitro antifungal assay showed a minimal inhibitory concentration of about 3 mg/ml with a fungicidal mode of action. In fact, treatment of F. solani by SPB1 lipopeptides generated excessive lyses of the mycelium and caused polynucleation and destruction of the related spores together with a total inhibition of spore production. Furthermore, an inhibition of germination potency accompanied with a high spore blowing was observed. Moreover, in order to be applied in agricultural field, in vivo antifungal activity was proved against the dry rot potato tubers caused by F. solani. Preventive treatment appeared as the most promising as after 20 days of fungi inoculation, rot invasion was reduced by almost 78 %, in comparison to that of non-treated one. When treating infected tomato plants, disease symptoms were reduced by almost 100 % when applying the curative method. Results of this study are very promising as it enables the use of the crude lipopeptide preparation of B. subtilis SPB1 as a potent natural fungicide that could effectively control the infection of F. solani in tomato and potato tubers at a concentration similar to the commercial fungicide hymexazol and therefore prevent the damage of olive tree.
Mostrar más [+] Menos [-]