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1.
Saccharomyces cerevisiae as the most simple eukaryotic organism is broadly accepted as a laboratory model organism. For the detection of potential toxic effects of pure compounds and complex composed samples like wastewater a miniaturised short‐term in vitro cyto‐ and genotoxicity screening assay was developed. The assay based on genetically modified S. cerevisiae cells deleted in the prominent drug efflux transporters Pdr5, Snq2, and Yor1 that facilitate pleiotropic drug resistance. The yeast strain devoid of these proteins that mediate the efflux of structurally diverse hydrophobic compounds exhibited an increased sensitivity to a variety of organic compounds. The DNA damage inducible RAD54 promoter fused to a yeast optimized derivative of the GFP (green fluorescent protein) gene from the jelly fish Aequorea victoria served as an indicator of DNA damage in this strain. Various pure compounds including the direct‐acting genotoxins methyl‐N‐nitro‐N‐nitrosoguanidine (MNNG), 4‐nitroquinoline‐N‐oxide (4‐NQO), methyl methanesulfonate (MMS) and hydroxyurea as well as the heavy metals cadmium and chromium(VI), the insecticide lindane and the central nervous system stimulant caffeine were tested exhibiting dose dependent induction of green fluorescence. All compounds were in parallel examined for chronic toxicity. A bioassay detecting simultaneously geno‐ and cytotoxic effects of potential toxicants in a single assay can be an important tool with a variety of applications in environmental monitoring and aquatic ecotoxicology. By partial automation and miniaturisation to microtitration scale this bioassay enables sensitive and fast biomonitoring for a multitude of samples. 相似文献
2.
Juan Bellas Liliana Saco-lvarez
scar Nieto Ricardo Beiras 《Marine pollution bulletin》2008,57(6-12):493
The toxicity of polycyclic aromatic hydrocarbons (PAHs) was determined using mussel, sea-urchin and ascidian embryo–larval bioassays. Fluorescent light exposure enhanced phenanthrene, fluoranthene, pyrene and hydroxypyrene toxicity in comparison with dark conditions, but not naphthalene and fluorene toxicity. The toxicity of PAHs was inversely related to their KOW values following QSAR models derived for baseline toxicity of general narcotics, whereas the obtained regression using toxicity data from photoactivated PAHs significantly departed from the general narcosis model. Also, the mixture toxicity of five PAHs to the larval growth of the sea-urchin was compared with predictions derived from the concentration addition concept, indicating less than additive effects. Finally, we compared our toxicity data with worst-case environmental concentrations in order to provide a preliminary estimate of the risk to the marine environment. Naphthalene, fluorene and pyrene are not considered to pose a risk to sea-urchin, mussel or ascidian larvae, whilst phenanthrene and fluoranthene may pose a risk for mussel and sea-urchin. Moreover, a higher risk for those species is expected when we consider the photoactivation of the PAHs. 相似文献
3.
Contradictory results are reported for the behaviour of quaternary ammonium compounds (QACs) in sewage treatment plants (STPs). QACs may sorb onto activated sludge. Only little information is available with respect to effects of QACs against bacteria in STPs. Only 5 to 15 % of bacteria present in sewage sludge can be detected by means of culture dependent microbiological methods. The shift of the bacterial populations due to effects of test compounds have not been studied up to now with culture independent methods. The microbial populations shift was studied in situ using culture independent chemotaxonomy profiling ubiquinones and polyamines. Additionally, toxic effects of QACs against bacteria present in the test vessels of the Zahn‐Wellens test (OECD 302 B) were assessed with a toxicity control in the test. The ubiquinone profiles representing changes in Gram‐negative populations mainly showed that the activated sludge was affected only in test vessels containing benzalkonium chloride. According to chemotaxonomy Acinetobacter or/and some members of Pseudomonas spp. have been selected by benzalkonium chloride after some adaptation period (8 to 12 days). 相似文献
4.
Toxicity of soil spiked with water soluble and insoluble contaminants was assessed with bacteria. Three bioassays were used with common soil bacteria. Water soluble fractions from the soils were estimated in microtiterplates via dehydrogenase activity of B. cereus and growth of P. putida. A new method was developed using B. cereus to include effects of soil particles with bound contaminants. As contaminants p-nitrophenol and 2-naphthol were tested in these systems. Results indicated that the concentration of the contaminants in the soil solution is determined by soil properties. Toxicity of water soluble fractions was not only a result of the toxicant's concentration but further modified by soluble components of the soils. It is not possible to assess soil pollution from toxicity of the water soluble fraction in general, because unknown factors of the soluble soil fraction can influence toxicity greatly. The newly developed contact bioassay with B. cereus showed clearly higher toxicity of 2-naphthol estimated in soil suspension than did the comparable test system with the same bacteria using water soluble fractions only. The results stress the importance of including soil particles into bioassay procedures. It was shown that also water insoluble, bound contaminants can act as toxicants. For an estimation of toxicity under conditions more relevant for the environment, the suggested test system can provide useful information to bioavailability of bound contaminants. 相似文献
5.
The release of genetically engineered microorganisms may occur from research laboratories of production plants. The most important pathway of release is via the sewage system and the sewage treatment plants into surface waters. The growth of these organisms might represent a risk to the environment. Therefore the growth of a genetically engineered strain of E. coli K-12 was investigated. Aqueous supernatant from sewage sludge of two domestic sewage plants was used as medium. This medium was treated with sterile filtration and amended with nutrients. The test strain E. coli K-12 W3110iqM15Nalr(pBR322) did not show permanent growth under the conditions employed. The result is interpreted by the presence of bacteriophages and the poor nutritional conditions in the medium. 相似文献
6.
《Marine pollution bulletin》2009,58(6-12):493-502
The toxicity of polycyclic aromatic hydrocarbons (PAHs) was determined using mussel, sea-urchin and ascidian embryo–larval bioassays. Fluorescent light exposure enhanced phenanthrene, fluoranthene, pyrene and hydroxypyrene toxicity in comparison with dark conditions, but not naphthalene and fluorene toxicity. The toxicity of PAHs was inversely related to their KOW values following QSAR models derived for baseline toxicity of general narcotics, whereas the obtained regression using toxicity data from photoactivated PAHs significantly departed from the general narcosis model. Also, the mixture toxicity of five PAHs to the larval growth of the sea-urchin was compared with predictions derived from the concentration addition concept, indicating less than additive effects. Finally, we compared our toxicity data with worst-case environmental concentrations in order to provide a preliminary estimate of the risk to the marine environment. Naphthalene, fluorene and pyrene are not considered to pose a risk to sea-urchin, mussel or ascidian larvae, whilst phenanthrene and fluoranthene may pose a risk for mussel and sea-urchin. Moreover, a higher risk for those species is expected when we consider the photoactivation of the PAHs. 相似文献
7.
An in vivo SCID mouse infectivity assay was used to determine its capacity to detect the infectivity of low concentrations of Cryptosporidium parvum oocysts in water. This biological test can be applied to demonstrate oocysts infectivity in water samples derived from drinking water supply and/or environmental sources. 相似文献
8.
This article reports the levels of heavy metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in sewage sludges taken from two wastewater treatment plants (WWTPs) in Konya (Turkey) as well as their toxicity. The concentrations of heavy metals, including Cd, Cr, Cu, Ni, Pb, Zn in sludge samples from plant #2 did not exceed the limits described in both Turkish and European Union (EU) regulations. The similar result was observed in samples obtained from plant #1, except for sludge taken in May 2010. The ΣPAHs concentration ranging from 960 to 7680 µg/kg dry matter shows that sewage sludges from plant #1 could be used for agricultural purpose. However, sewage sludges from plant #2 (ΣPAHs: 1077–17 509 µg/kg dry matter) was not suitable for using in agriculture. The concentrations of ΣPCBs in all investigated sludges from plant #1 (7.46–709.36 µg/kg dry matter) and plant #2 (14.12–788.47 µg/kg dry matter) were lower than the limits reported in Turkish and EU regulations. The probable sources of PAHs and PCBs in sludges were also determined. The ecotoxicological tests examined on Vibrio fischeri and Lepidium sativum organisms showed that sludges from plant #1 had no significant toxic effect, while sludges from plant #2 had acute toxic property. Finally, all the results showed that sewage sludges from plant #1 had potential for being used in agriculture. 相似文献
9.
Polycyclic aromatic hydrocarbons (PAHs) present serious problems in the environment because they may affect negatively human health and alter native ecological communities. Phytoremediation has long been recognized as an efficient method of eliminating PAH pollutants from soil. A pot experiment was conducted in greenhouse conditions to investigate the capability of three plant species, Medicago sativa, Brassica napus, and Lolium perenne, to promote the degradation of pyrene by measuring their growth on pyrene‐contaminated soils. After 90 days, pyrene concentration in soils declined by 32, 30, and 28%, respectively, with M. sativa, B. napus, and L. perenne, whereas it decreased only by 18% in the control soil without plants. These results indicated that pyrene was successfully removed by plants used. In particular, M. sativa showed the highest capacity for pyrene dissipation in soil, whereas L. perenne was more efficient in limiting adverse effects of pyrene contamination. In addition, the contaminant pyrene was undetectable in shoots and roots of the three species, likely because plant roots can stimulate soil microbial biomass and oxygen transport to the rhizosphere, thus facilitating indirectly the degradation process of pyrene. Further studies are in progress to evaluate the possible adsorption of pyrene to soil organic matter. 相似文献
10.
The toxicity of polycyclic aromatic hydrocarbons (PAHs) was determined using mussel, sea-urchin and ascidian embryo-larval bioassays. Fluorescent light exposure enhanced phenanthrene, fluoranthene, pyrene and hydroxypyrene toxicity in comparison with dark conditions, but not naphthalene and fluorene toxicity. The toxicity of PAHs was inversely related to their K(OW) values following QSAR models derived for baseline toxicity of general narcotics, whereas the obtained regression using toxicity data from photoactivated PAHs significantly departed from the general narcosis model. Also, the mixture toxicity of five PAHs to the larval growth of the sea-urchin was compared with predictions derived from the concentration addition concept, indicating less than additive effects. Finally, we compared our toxicity data with worst-case environmental concentrations in order to provide a preliminary estimate of the risk to the marine environment. Naphthalene, fluorene and pyrene are not considered to pose a risk to sea-urchin, mussel or ascidian larvae, whilst phenanthrene and fluoranthene may pose a risk for mussel and sea-urchin. Moreover, a higher risk for those species is expected when we consider the photoactivation of the PAHs. 相似文献
11.
In an attempt to model the effect of slope on the dynamics of lava flow emplacement, four distinct morphologies were repeatedly produced in a series of laboratory simulations where polyethylene glycol (PEG) was extruded at a constant rate beneath cold sucrose solution onto a uniform slope which could be varied from 1° through 60°. The lowest extrusion rates and slopes, and highest cooling rates, produced flows that rapidly crusted over and advanced through bulbous toes, or pillows (similar to subaerial “toey” pahoehoe flows and to submarine pillowed flows). As extrusion rate and slope increased, and cooling rate decreased, pillowed flows gave way to rifted flows (linear zones of liquid wax separated by plates of solid crust, similar to what is observed on the surface of convecting lava lakes), then to folded flows with surface crusts buckled transversely to the flow direction, and, at the highest extrusion rates and slopes, and lowest cooling rates, to leveed flows, which solidified only at their margins. A dimensionless parameter, Ψ, primarily controlled by effusion rate, cooling rate and flow viscosity, quantifies these flow types. Increasing the underlying slope up to 30° allows the liquid wax to advance further before solidifying, with an effect similar to that of increasing the effusion rate. For example, conditions that produce rifted flows on a 10° slope result in folded flows on a 30° slope. For underlying slopes of 40°, however, this trend reverses, slightly owing to increased gravitational forces relative to the strength of the solid wax. Because of its significant influence on heat advection and the disruption of a solid crust, slope must be incorporated into any quantitative attempt to correlate eruption parameters and lava flow morphologies. These experiments and subsequent scaling incorporate key physical parameters of both an extrusion and its environment, allowing their results to be used to interpret lava flow morphologies on land, on the sea floor, and on other planets. 相似文献
12.
With the Water Framework Directive (WFD) the European Commission (EC) is requested to define environmental quality standards for pollutants to protect aquatic life in surface waters. Quality standards have to be derived by a scientific risk assessment and should not be exceeded. The recommended quality standards are mainly based on long term toxicological tests with algae, crustaceans and fish. The lowest effect concentration is divided by an assessment factor between 10 and 1000, which considers the data quality and quantity. In this work funded by the German Länder Working Party on Water (Länderarbeitsgemeinschaft Wasser – LAWA) environmental quality standards for 40 considered relevant substances were derived for aquatic ecosystems. The data sheets cover the identification of the compounds, their behaviour in the environment (physical‐chemical properties, biotic and abiotic degradation, sorption, bioaccumulation), information about mode of action, uses, analytical determination and available quality criteria. Ecotoxicological effect concentrations for bacteria, algae, protozoa, aquatic plants, crustaceans, fish, amphibians, insects and molluscs are listed. For 17 of the 40 hazardous substances investigated, quality objectives above 1 μg/L were derived. For 12 substances the values were between 0.1 μg/L and 1 μg/L and for 5 substances lower than 0.1 μg/L. Incomplete ecotoxicological data sets of the remaining compounds do not allow the derivation of quality standards. Especially for drugs further ecotoxicological test results are needed. 相似文献
13.
Seasonal Occurrence of Species of Saprolegniales and Leptomitales in Lake Aue and the River Fulda in Kassel (Hesse) with Special Consideration of Fish Pathogenic Species In this study, we examined the occurrence of species of aquatic Oomycetes of Saprolegniales und Leptomitales in Lake Aue and the river Fulda in Kassel (Hesse, Germany) with special consideration of fish pathogenic species. We monthly collected water samples of both water bodies from July 2003 to June 2004. The baiting method was used to gain an insight into the specific seasonal occurrence of aquatic Oomycetes. Some species show a seasonal periodicity. Nine of 11 species of Saprolegniales isolated from the two water bodies, and Leptomitus lacteus (Roth) C. Agardh, one of the two species of Leptomitales, were already documented on fish according to references. Additionally, 7 of 10 species could according to references already be detected on fish species present in the two water bodies. Simultaneous measurements of limnological‐chemical parameters were done during the sampling of water for the isolation of aquatic Oomycetes. The results of some measurements, concerning the river Fulda, were additionally compared with the predetermined guideline values and limit values of water bodies of fish of the “Cyprinid region”. 相似文献
14.
Pertrogenesis and tectonic implications of the late Jurassic basic rocks from the northern Shi‐Hang zone,Southeast China 
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下载免费PDF全文 Qing Zhou Yao–hui Jiang Shi–yong Liao Peng Zhao Ru–ya Jia Zheng Liu Guo–chang Wang Chun–yu Ni 《Island Arc》2016,25(3):235-250
The tectonic setting of the late mesozoic of South China is in a debate between two schools of thought: an intra‐continental rift zone along a passive continental margin or active rifting associated with subduction of the paleo‐Pacific Plate. In this study, we present new sensitive high‐resolution ion microprobe (SHRIMP) U‐Pb zircon ages, along with geochemical data of three basic dikes that cross‐cut the Dexing porphyry copper deposit. The deposit is the largest of its kind in eastern China and part of large scale mineralization associated with Mesozoic magmatic activity in the area. Our results indicate that the dikes were emplaced in the Late Jurassic with an average U‐Pb age of 153.5 ± 2.4 Ma. The intrusions have bulk εNd(t) of ca +0.7 and zircon εHf(t) value of +1.54 to +6.92. Based on relatively enriched light rare earth elements (LREE) and depleted high‐field‐strength elements (HFSE) abundances with pronounced negative Ta–Nb, Hf–Zr and Ti anomalies in multi‐element diagrams, we propose that these dikes were derived from a subduction‐modified lithospheric mantle source. The variability in Hf isotopes identifies some degree of crustal contaminations. Our data support a scenario with a back‐arc extensional setting or an intra‐arc rift environment associated with the westward subduction of the paleo‐Pacific Plate at or prior to the late Jurassic as the most likely cause for these subduction signatures. 相似文献
15.
环太湖地区经济发达,人口密集,近年来面临严重的富营养化、生境退化和外来水生物种入侵等环境问题.为明确环太湖地区河道和湖泊沿岸带水生植物多样性现状,于2018年开展本地和外来水生植物多样性调查.结果表明:(1)在环太湖地区共计进行65个群落样方调查分析,记录到38种水生植物,分属22科29属;(2)环太湖地区31个河道样方中入侵沉水植物水盾草重要值最高,其次为另一种入侵漂浮植物凤眼蓝,在34个湖泊沿岸带样方中凤眼蓝重要值最高;(3)环太湖地区河道和湖泊沿岸带样方生物多样性分别随着水盾草和凤眼蓝盖度的增加而降低,表明外来入侵植物影响水生植物生物多样性.环太湖地区湖泊需加强防范凤眼蓝漂浮生长分布范围扩大和水盾草沿河道入侵太湖湖区.这一地区同时面对水生植物覆盖面积减少和外来植物入侵问题,建议进行全太湖流域水生植物分布区域和生物多样性摸底普查,加强对外来入侵植物传播的监控,建立水生植物自然保护区. 相似文献
16.
沉水植物是浅水湖泊生态系统的关键种群,对水环境质量及水生生态系统结构有重要影响.以东太湖大水港和湖湾区2个典型的具有不同污染程度的沉水植物苦草(Vallisneria natans)生长区域为研究对象,考察苦草对多环芳烃(PAHs)的修复效果.结果表明,经过34 d植物修复试验,重度污染的东太湖大水港沉积物中PAHs的去除率为62%,沉积物中PAHs降解速率为0.024 d-1;而中度污染的东太湖湖湾区沉积物的PAHs去除率为42%,其降解速率为0.015 d~(-1).种植苦草的沉积物中PAHs的降解速率是未种植苦草的降解速率的2~3倍.苦草对沉积物中高分子量PAHs的修复效果尤为显著.因此,苦草可以有效地用于PAHs污染沉积物的修复,尤其是在重污染和高分子量PAHs污染沉积物中,苦草的修复作用更加明显. 相似文献
17.
《Marine pollution bulletin》2014,81(1-2):222-233
Reverse osmosis membranes at many desalination plants are disinfected by periodic shock treatments with sodium metabisulphite, which have potentially toxic effects to the environment for marine life, although no empirical and experimental evidence for this is yet available. The aim of this study was to characterise for the first time, the physico-chemical modification of the marine environment and its biological effects, caused by hypersaline plumes during these membrane cleaning treatments. The case study was the Maspalomas II desalination plant, located in the south of Gran Canaria (Canary Islands, Spain). Toxicity bioassays were performed on marine species characteristic for the infralittoral soft bottoms influenced by the brine plume (Synodus synodus and Cymodocea nodosa), and revealed a high sensitivity to short-term exposure to low sodium metabisulphite concentrations. The corrective measure of incorporating a diffusion system with Venturi Eductors reduced nearly all the areas of influence, virtually eliminating the impact of the disinfectant. 相似文献
18.
By enhancing the stock of piscivorous fish in a whole-lake experiment in Gräfenhain (Germany) since 1981 to such an extent that almost all planktivorous fish were exterminated, we examined the concept of “over-biomanipulation”. This hypothesis predicts that (a) extremely strong piscivory will allow uncontrolled development of large invertebrate predators and (b) these invertebrates can exert the same strong predation pressure on large herbivorous zooplankton as planktivorous fish. The hypothesis is tested the first time by a cross-comparison of the long-term response of the plankton community structure in the experimental lake (Piscivore L.) with (1) the intermediate response in the same lake and with (2) that of the long-term state in a nearby reference lake (Planktivore L.) densely inhabited by planktivorous fish (Leucaspius delineatus, a small cyprinid). The intermediate (1989–1992) response in Piscivore L. revealed a strong increase of the abundance of the invertebrate predator Chaoborus flavicans. Large daphnids were able to coexist with C. flavicans so that edible phytoplankton were suppressed and water transparency increased.As part (a) of the hypothesis predicts, the long-term response in Piscivore L. was characterized by the immigration of the larger predator Chaoborus obscuripes which displaced the smaller C. flavicans completely. The results support also part (b) of the hypothesis of “over-biomanipulation”: C. obscuripes-dominated Piscivore L. showed not much difference in biomasses of daphnids and total and edible phytoplankton as well as Secchi depth compared with fish-dominated Planktivore Lake. On the other hand, C. obscuripes-dominated Piscivore L. was characterized by distinctly lower biomass of daphnids, mean body volume of all crustaceans and Secchi depth as well as by higher biomass of edible phytoplankton compared with C. flavicans-dominated Piscivore Lake. We conclude that long-lasting success of biomanipulation cannot be achieved by extremely high piscivory leading to the almost complete extermination of planktivorous fish. 相似文献
19.
In situ phosphatase, esterase, lipase, and β‐glucuronidase activities were investigated in filamentous scum bacteria by ELF (enzyme labeled fluorescence)‐technology. Microthrix parvicella exhibited significant activities for all four enzymes with lipase activity being the highest. In situ activities were considerably higher in activated sludge as compared to scum indicating M. parvicella growth to occur mainly in the sludge fraction. “Nocardioform actinomycetes” showed significant activities for phosphatase, esterase, and β‐glucuronidase, lipase activity was only moderate. Activities revealed to be similar for activated sludge and scum. As population densities of enzyme‐active actinomycetes were noticeably higher in scum they presumably find good growth conditions in the scum layer. Enzyme activities in Nostocoida limicola morphotypes were only low with no lipase activity being detected. Due to their phylogenetic diversity activity assignment should be combined with fluorescence in situ hybridization (FISH). Numerous type 0041/0675 and type 1851 filaments showed all but lipase activity. However, some of their attached bacteria revealed to be lipase‐active. Only a few morphotype 0092 filaments revealed phosphatase, esterase, and β‐glucuronidase activity. ELF investigations proved suitable for monitoring in situ filamentous activity. Present imponderabilities of Eikelboom morphotype phylogenetic affiliation are discussed. 相似文献
20.
以宁波城区内河为研究对象,调研沉水植物在154条河中的分布情况,实测63个代表样点的水环境指标,分析秋、冬季沉水植物群落变化及生理变化.研究发现：宁波城区内仅有8条河流单一地生长有沉水植物轮叶黑藻（Hydrilla verticillata）、苦草（Vallisneria natans）和金鱼藻（Ceratophyllum demersum）中的1种;3种沉水植物分布与溶解氧、氧化还原电位和pH均呈显著正相关,与水深、氨氮（NH3-N）和总磷（TP）浓度均呈显著负相关;有沉水植物分布的河道水深较浅（约0.9 m）、水质更优（普遍优于V类）;与秋季相比,冬季3种植物的群落盖度均下降,轮叶黑藻和苦草体内丙二醛、过氧化氢含量升高,暗示植物细胞受损;而3种沉水植物均具有一定耐低温胁迫能力,主要表现为体内抗氧化酶活性、可溶性蛋白和可溶性糖含量升高.结果表明,水深、NH3-N、TP、溶解氧以及低温可能会影响城区内河沉水植物的生长与分布. 相似文献