Уточнить поиск
Результаты 2541-2550 из 3,208
Biodegradation of polycyclic aromatic hydrocarbons by Trichoderma species: a mini review Полный текст
2015
Zafra, German | Cortés-Espinosa, Diana V.
Fungi belonging to Trichoderma genus are ascomycetes found in soils worldwide. Trichoderma has been studied in relation to diverse biotechnological applications and are known as successful colonizers of their common habitats. Members of this genus have been well described as effective biocontrol organisms through the production of secondary metabolites with potential applications as new antibiotics. Even though members of Trichoderma are commonly used for the commercial production of lytic enzymes, as a biological control agent, and also in the food industry, their use in xenobiotic biodegradation is limited. Trichoderma stands out as a genus with a great range of substrate utilization, a high production of antimicrobial compounds, and its ability for environmental opportunism. In this review, we focused on the recent advances in the research of Trichoderma species as potent and efficient aromatic hydrocarbon-degrading organisms, as well as aimed to provide insight into its potential role in the bioremediation of soils contaminated with heavy hydrocarbons. Several Trichoderma species are associated with the ability to metabolize a variety of both high and low molecular weight polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, chrysene, pyrene, and benzo[a]pyrene. PAH-degrading species include Trichoderma hamatum, Trichoderma harzianum, Trichoderma reesei, Trichoderma koningii, Trichoderma viride, Trichoderma virens, and Trichoderma asperellum using alternate enzyme systems commonly seen in other organisms, such as multicooper laccases, peroxidases, and ring-cleavage dioxygenases. Within these species, T. asperellum stands out as a versatile organism with remarkable degrading abilities, high tolerance, and a remarkable potential to be used as a remediation agent in polluted soils.
Показать больше [+] Меньше [-]Determination of 2,8-dichlorodibenzo-p-dioxin in toothpaste and mouthwash consumer products using GC-MS Полный текст
2015
Wu, Jianlin | Hu, Chuanqin | Li, Charlie Chunlin | Cai, Zongwei | Hu, Di
A gas chromatography–mass spectrometry (GC-MS) method was developed for the identification and quantification of 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD) in toothpaste and mouthwash consumer products. Liquid–liquid extraction and solid-phase extraction were used in the sample preparation. The limit of detection was 0.96 ng/g in toothpaste and 0.83 ng/g in mouthwash. The accuracy represented by relative errors was less than 12.5 %. The intra-day and inter-day precision, which are represented by the relative standard deviation values, were within 11.2 and 10.6 %, respectively. The method was successfully applied to analyze 2,8-DCDD in toothpaste and mouthwash products, as well as that from the photo-degradation of triclosan spiked in both sample matrix.
Показать больше [+] Меньше [-]Effects of drought on cadmium accumulation in peanuts grown in a contaminated calcareous soil Полный текст
2015
Xia, Shenglan | Wang, Xvming | Su, Genqiang | Shi, Gangrong
This study aimed to investigate the effects of drought stress on cadmium (Cd) accumulation in peanut (Arachis hypogaea L.) grown in contaminated calcareous soils. Five peanut cultivars were grown in a calcareous soil spiked with 4 mg Cd kg⁻¹ soil (dry weight) under well-watered, mild drought, and severe drought conditions. The biomass production, gas exchange, spectral reflectance, and Cd accumulation in plant tissues were determined. The five cultivars significantly differed from each other in biomass production, gas exchange, spectral reflectance, and Cd accumulation. The effect of drought on Cd accumulation in peanuts varies with plant tissues, cultivars, and developmental stages. Drought decreased root Cd concentrations in seedlings of the two high Cd-accumulating cultivars (Haihua 1 and Zhenghong 3), which is associated with increasing leaf active Fe content. However, for the mature plants, drought stress caused an increase in Cd accumulation in roots, pod walls, and seeds depending on peanut cultivars. Negative correlations were found between seed Cd concentration and biomasses in both preflowering seedlings and mature plants. The seed Cd concentration in mature plants was also observed to be positively correlated with the shoot Cd concentration in preflowering seedlings. The increased Cd concentration in seeds of drought-stressed peanut plants grown in Cd-contaminated calcareous soils might be attributed to the drought-induced decrease of biomass production.
Показать больше [+] Меньше [-]Application of the GREAT-ER model for environmental risk assessment of nonylphenol and nonylphenol ethoxylates in China Полный текст
2015
Zhang, Lai | Cao, Yan | Hao, Xuewen | Zhang, Yongyong | Liu, Jianguo
The environmental risk presented by “down-the-drain” chemicals to receiving rivers in large urban areas has received increasing attention in recent years. Geo-referenced Regional Environmental Assessment Tool for European Rivers (GREAT-ER) is a typical river catchment model that has been specifically developed for the risk assessment of these chemicals and applied in many European rivers. By utilizing the new version of the model, GREAT-ER 3.0, which is the first completely open source software for worldwide application, this study represents the first attempt to conduct an application of GREAT-ER in the Wenyu River of China. Aquatic exposure simulation and an environmental risk assessment of nonylphenol (NP) and its environmental precursor nonylphenol ethoxylates (NPEOs) were conducted effectively by GREAT-ER model, since NP is one of typical endocrine disrupting chemicals (EDCs) and its environmental precursor NPEOs as a “down-the-drain” chemical are extensively used in China. In the result, the predicted environmental concentrations (PECs) of NP and NPEOs in the water of Wenyu River were 538 and 4320 ng/L, respectively, at the regional scale, and 1210 and 8990 ng/L, respectively, at the local scale. From the results profile of the RCR, the combination of high emissions from large STPs with insufficient dilution of the river caused the high RCR. The PECs of NP in the sediment were in the range of 216.8–8218.3 ng/g (dry weight), which was consistent with the available monitoring data. The study showed the worldwide applicability and reliability of GREAT-ER as a river catchment model for the risk assessment of these chemicals and also revealed the general environmental risks presented by NP and NPEOs in the Wenyu River catchment in Beijing due to the extensive use of these chemicals. The results suggest that specific control or treatment measures are probably warranted for these chemicals to reduce their discharge in major cities.
Показать больше [+] Меньше [-]Investigation of the tritium content in surface water, bottom sediments (zoobenthos), macrophytes, and fish in the mid-stream region of the Yenisei River (Siberia, Russia) Полный текст
2015
Bondareva, Lydia | Schultz, Michael K.
The potential sources of tritium input to the Yenisei River ecosystem are derived from local operations of nuclear facilities of the Mining and Chemical Combine operated by the state-owned Rosatom corporation and from sources derived from global weapons testing fallout and nuclear power. The background tritium concentrations in zoobenthos, bottom sediments, relevant commercial fish species, and widespread endogenous aquatic plants have been obtained for the first time in this region. Our results demonstrate that the major input term of tritium to this region of the Yenisei is derived from nearby mining operations of Rosatom, with tritium concentrations in aquatic plants marginally exceeding the observed background values obtained from upstream control sample collection sites.
Показать больше [+] Меньше [-]Occurrence and distribution of sulfonamides, tetracyclines, quinolones, macrolides, and nitrofurans in livestock manure and amended soils of Northern China Полный текст
2015
Hou, Jie | Wan, Weining | Mao, Daqing | Wang, Chong | Mu, Quanhua | Qin, Songyan | Luo, Yi
A feasible and rapid analysis for the simultaneous determination of sulfonamides (SAs), tetracyclines (TCs), fluoroquinolones (FQs), macrolides (MACs) and nitrofurans (NFs) in livestock manure and soils was established by solid-phase extraction (SPE)-ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS). A total of 32 manure and 17 amended soil samples from the Liaoning and Tianjin areas in Northern China were collected for analysis. The largest detected frequencies and concentrations in manure samples were those of TCs (3326.6 ± 12,302.6 μg/kg), followed by FQs (411.3 ± 1453.4 μg/kg), SAs (170.6 ± 1060.2 μg/kg), NFs (85.1 ± 158.1 μg/kg), and MACs (1.4 ± 4.8 μg/kg). In general, veterinary antibiotics (VAs) were detected with higher concentrations in swine and chicken manure than in cattle manure, reflecting the heavy usage of VAs in swine and chicken husbandry in the studied area. Furthermore, higher residues of antibiotics were found in piglet and fattening swine manure than in sow manure. In addition, TCs were the most frequently (100 %) detected antibiotics in amended soil with higher concentrations (up to 10,967.1 μg/kg) than any other VAs. The attenuation of SAs was more obvious than TCs in amended soil after fertilization, which can most likely be attributed to the stronger sorption of TCs than SAs to soil organic matter through cation exchange. This study illustrated the prevalence of TCs detected in both animal manure and fertilized agricultural soils in Northern China, which may increase the risk to human health through the food chain. Thus, TCs should be given more attention in the management of veterinary usage in livestock husbandry.
Показать больше [+] Меньше [-]Effect of plant growth-promoting bacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) inoculation on oats in saline-alkali soil contaminated by petroleum to enhance phytoremediation Полный текст
2015
Xun, Feifei | Xie, Baoming | Liu, Shasha | Guo, Changhong
To investigate the effect of plant growth-promoting bacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on phytoremediation in saline-alkali soil contaminated by petroleum, saline-alkali soil samples were artificially mixed with different amount of oil, 5 and 10 g/kg, respectively. Pot experiments with oat plants (Avena sativa) were conducted under greenhouse condition for 60 days. Plant biomass, physiological parameters in leaves, soil enzymes, and degradation rate of total petroleum hydrocarbon were measured. The result demonstrated that petroleum inhibited the growth of the plant; however, inoculation with PGPR in combination with AMF resulted in an increase in dry weight and stem height compared with noninoculated controls. Petroleum stress increased the accumulation of malondialdehyde (MDA) and free proline and the activities of the antioxidant enzyme such as superoxide dismutase, catalase, and peroxidase. Application of PGPR and AMF augmented the activities of three enzymes compared to their respective uninoculated controls, but decreased the MDA and free proline contents, indicating that PGPR and AMF could make the plants more tolerant to harmful hydrocarbon contaminants. It also improved the soil quality by increasing the activities of soil enzyme such as urease, sucrase, and dehydrogenase. In addition, the degradation rate of total petroleum hydrocarbon during treatment with PGPR and AMF in moderately contaminated soil reached a maximum of 49.73 %. Therefore, we concluded the plants treated with a combination of PGPR and AMF had a high potential to contribute to remediation of saline-alkali soil contaminated with petroleum.
Показать больше [+] Меньше [-]Effects of neonicotinoids and fipronil on non-target invertebrates Полный текст
2015
Pisa, L. W. | Amaral-Rogers, V. | Belzunces, L. P. | Bonmatin, J. M. | Downs, C. A. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. | Liess, M. | McField, M. | Morrissey, C. A. | Noome, D. A. | Settele, J. | Simon-Delso, N. | Stark, J. D. | Van der Sluijs, J. P. | Van Dyck, H. | Wiemers, M.
Effects of neonicotinoids and fipronil on non-target invertebrates Полный текст
2015
Pisa, L. W. | Amaral-Rogers, V. | Belzunces, L. P. | Bonmatin, J. M. | Downs, C. A. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. | Liess, M. | McField, M. | Morrissey, C. A. | Noome, D. A. | Settele, J. | Simon-Delso, N. | Stark, J. D. | Van der Sluijs, J. P. | Van Dyck, H. | Wiemers, M.
We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.
Показать больше [+] Меньше [-]Effects of neonicotinoids and fipronil on non-target invertebrates Полный текст
2015
Pisa, L.W. | Amaral-Rogers, V. | Belzunces, Luc | Bonmatin, J-M. | Downs, C.A. | Goulson, D. | Kreutzweiser, D.P. | Krupke, C. | Liess, M. | Mcfield, M. | Morrissey, C.A. | Noome, D.A. | Settele, J. | Simon-Delso, N. | Stark, J. D. | van Der Sluijs, Jeroen P. | van Dyck, H. | Wiemers, M. | Universiteit Utrecht / Utrecht University [Utrecht] | Buglife | Abeilles et environnement (AE) ; Institut National de la Recherche Agronomique (INRA) | Centre de biophysique moléculaire (CBM) ; Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Haereticus Environmental Laboratory ; Partenaires INRAE | School of Life Sciences ; University of Sussex | Canadian Forest Service ; Natural Resources Canada (NRCan) | Department of Entomology ; Michigan State University [East Lansing] ; Michigan State University System-Michigan State University System | Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) | Smithsonian Institution | University of Saskatchewan [Saskatoon, Canada] (U of S) | Kijani, Kasungu national park ; Partenaires INRAE | Department of Community Ecology ; Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) | German Centre for Integrative Biodiversity Research (iDiv) | Centre Apicole de Recherche et Information ; Partenaires INRAE | Washington State University (WSU) | Centre for the Study of the Sciences and the Humanities (SVT) ; University of Bergen (UiB) | Université Catholique de Louvain = Catholic University of Louvain (UCL)
International audience | We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (<em>Apis mellifera</em>) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.
Показать больше [+] Меньше [-]Effects of neonicotinoids and fipronil on non-target invertebrates | Effets des néonicotinoïdes et du fipronil sur les invertébrés Полный текст
2015
Pisa, L. W. | Amaral-Rogers, V. | Belzunces, L.P. | Bonmatin, Jean-Marc | Downs, C. A. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. | Liess, M. | Mcfield, M. | Morrissey, C. A. | Noome, D. A. | Settele, J. | Simon-Delso, N. | Stark, J. D. | van Der Sluijs, J. P. | van Dyck, H. | Wiemers, M. | Laboratoire de Toxicologie Environnementale (LTE) ; Institut National de la Recherche Agronomique (INRA) | Centre de biophysique moléculaire (CBM) ; Université d'Orléans (UO)-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) | Department Community Ecology [UFZ Leipzig] ; Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ)
We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.
Показать больше [+] Меньше [-]Effects of neonicotinoids and fipronil on non-target invertebrates Полный текст
2015
Amaral-Rogers, V. | Belzunces, Luc | Bonmatin, J-M. | Downs, C.A. | Goulson, D. | Kreutzweiser, D.P. | Krupke, C. | Liess, M. | McField, M. | Morrissey, C.A. | Noome, D.A. | Settele, J. | Simon-Delso, N. | Stark, J. D. | Van der Sluijs, Jeroen P. | Van Dyck, H. | Wiemers, M.
We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. Thereis a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.
Показать больше [+] Меньше [-]Effect of concentration gradients on biodegradation in bench-scale sand columns with HYDRUS modeling of hydrocarbon transport and degradation Полный текст
2015
Horel, Agota | Schiewer, Silke | Misra, Debasmita
The present research investigated to what extent results obtained in small microcosm experiments can be extrapolated to larger settings with non-uniform concentrations. Microbial hydrocarbon degradation in sandy sediments was compared for column experiments versus homogenized microcosms with varying concentrations of diesel, Syntroleum, and fish biodiesel as contaminants. Syntroleum and fish biodiesel had higher degradation rates than diesel fuel. Microcosms showed significantly higher overall hydrocarbon mineralization percentages (p < 0.006) than columns. Oxygen levels and moisture content were likely not responsible for that difference, which could, however, be explained by a strong gradient of fuel and nutrient concentrations through the column. The mineralization percentage in the columns was similar to small-scale microcosms at high fuel concentrations. While absolute hydrocarbon degradation increased, mineralization percentages decreased with increasing fuel concentration which was corroborated by saturation kinetics; the absolute CO₂ production reached a steady plateau value at high substrate concentrations. Numerical modeling using HYDRUS 2D/3D simulated the transport and degradation of the investigated fuels in vadose zone conditions similar to those in laboratory column experiments. The numerical model was used to evaluate the impact of different degradation rate constants from microcosm versus column experiments.
Показать больше [+] Меньше [-]Impact of acute Cd2+ exposure on the antioxidant defence systems in the skin and red blood cells of common carp (Cyprinus carpio) Полный текст
2015
Ferencz, Ágnes | Hermesz, Edit
Cd²⁺-induced oxidative stress and its effects on the expression of stress biomarkers and on macromolecule damage in the skin and blood of common carp were studied. Both tissues play important roles in the defence mechanisms against external hazards, serving as an anatomical barrier and as connecting tissue between the organs. In the skin, the production of peroxynitrite anion and hydrogen peroxide was almost doubled after exposure to 10 mg/L Cd²⁺. The accumulation of these oxidant molecules suggests an intensive production of superoxide anion and nitrogen monoxide and the development of oxidative and/or nitrosative stress. Although the metallothioneins and the components of the glutathione redox system were activated in the skin, the accumulation of reactive intermediates led to the enhanced damage of lipid molecules after 24 h of metal exposure. In the blood, the basal levels of metallothionein messenger RNAs (mRNAs) were 2–2.5-fold of that measured in the skin. This high level of metallothionein expression could be the reason that the blood was less affected by an acute Cd²⁺challenge and the metallothionein and glutathione systems were not activated.
Показать больше [+] Меньше [-]