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Effect of exogenous abscisic acid on the level of antioxidants in Atractylodes macrocephala Koidz under lead stress
2013
Wang, Jinchuang | Chen, Juan | Pan, Kaiwen
This study hypothesized that the positive or negative effects of exogenous abscisic acid (ABA) on oxidative stress caused by lead were dose dependent. The effects of different levels of ABA (2.5, 5, and 10 mg L⁻¹) on lead toxicity in the leaves of Atractylodes macrocephala were studied by investigating plant growth, soluble sugars, proteins, lipid peroxidation, and antioxidative enzymes. Excess Pb inhibited root dry weight, root length, and the number of lateral roots, but increased shoot growth. In addition, lead stress significantly decreased the levels of chlorophyll pigments, protein, and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD). Different levels of ABA significantly increased SOD, CAT, POD, and APX activities, but decreased the level of hydrogen peroxide and malondialdehyde in nonstressed plants. Exogenous application of 2.5 mg L⁻¹ ABA detoxified the stress-generated damages caused by Pb and also enhanced plant growth, soluble sugars, proteins, and all four antioxidant enzyme activities but reduced Pb uptake of lead-stressed plant compared to lead treatment alone. However, the toxic effects of Pb were further increased by the applications of 5 and 10 mg L⁻¹ ABA. The levels of antioxidants caused by a low concentration of exogenous ABA might be responsible for minimizing the Pb-induced toxicity in A. macrocephala.
Mostrar más [+] Menos [-]Distribution of selected essential (Co, Cu, Fe, Mn, Mo, Se, and Zn) and nonessential (Cd, Pb) trace elements among protein fractions from hepatic cytosol of European chub (Squalius cephalus L.)
2013
Krasnići, Nesrete | Dragun, Zrinka | Erk, Marijana | Raspor, Biserka
Association of selected essential (Co, Cu, Fe, Mn, Mo, Se, and Zn) and nonessential (Cd, Pb) trace elements with cytosolic proteins of different molecular masses was described for the liver of European chub (Squalius cephalus) from weakly contaminated Sutla River in Croatia. The principal aim was to establish basic trace element distributions among protein fractions characteristic for the fish living in the conditions of low metal exposure in the water. The fractionation of chub hepatic cytosols was carried out by size exclusion high performance liquid chromatography (SE-HPLC; Superdex™ 200 10/300 GL column), and measurements were performed by high resolution inductively coupled plasma mass spectrometry (HR ICP-MS). Elution profiles of essential elements were mostly characterized by broad peaks covering wide range of molecular masses, as a sign of incorporation of essential elements in various proteins within hepatic cytosol. Exceptions were Cu and Fe, with elution profiles characterized by sharp, narrow peaks indicating their probable association with specific proteins, metallothionein (MT), and ferritin, respectively. The main feature of the elution profile of nonessential metal Cd was also single sharp, narrow peak, coinciding with MT elution time, and indicating almost complete Cd detoxification by MT under the conditions of weak metal exposure in the water (dissolved Cd concentration ≤0.3 μg L⁻¹). Contrary, nonessential metal Pb was observed to bind to wide spectrum of proteins, mostly of medium molecular masses (30–100 kDa), after exposure to dissolved Pb concentration of ~1 μg L⁻¹. The obtained information within this study presents the starting point for identification and characterization of specific metal/metalloid-binding proteins in chub hepatic cytosol, which could be further used as markers of metal/metalloid exposure or effect on fish.
Mostrar más [+] Menos [-]Spatial gradients of OCPs in European butter—integrating environmental and exposure information
2013
Weiss, Jana | Müller, Anne | Vives, Ingrid | Mariani, Giulio | Umlauf, Gunther
The Stockholm Convention and the Global Monitoring Plan encourage the production of monitoring data to effectively evaluate the presence of the persistent organic pollutants (POPs) in all regions, in order to identify changes in levels over time, as well as to provide information on their regional and global environmental transport. Here, we report the first step of two to investigate whether butter is a feasible matrix to screen with the purpose to reflect regional ambient atmospheric air levels of POPs. The first step described here is to generate monitoring data; the second is to investigate the relationship between the two matrixes, i.e., POP concentrations in air and butter, which will be reported in another article published in this journal. Here, the 27 organochlorine pesticides listed under the Stockholm Convention have been analyzed in 75 butter samples from Europe. The general conclusions were as follows: Total organochlorine pesticide concentration is lower in butter from northern and central Europe. The spatial gradient of 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane and hexachlorocyclohexane is increasing in the eastern region of Europe (Romania, Bulgaria, and Ukraine), dieldrin towards France, and endosulfan levels were elevated on the Azores Island in the Atlantic Ocean. One butter sample from Romania exceeded the European Maximum Residue Limit value for lindane, but the other butter pesticide levels were all below the limit values. The dataset reported here can be used for the calibration of the air–grass–dairy products model, which would support the feasibility to use butter as biomonitor for measuring POP levels in ambient air.
Mostrar más [+] Menos [-]The porifera Hymeniacidon perlevis (Montagu, 1818) as a bioindicator for water quality monitoring
2013
Mahaut, Marie-Laure | Basuyaux, Olivier | Baudinière, Estelle | Chataignier, Claire | Pain, Julien | Caplat, Christelle
Because sponges are promising bioindicators, we present here a multispecies comparison of the bioconcentration capacity for copper, zinc and the hydrocarbon fluoranthene. The spatial distribution of sponge populations was studied in 17 areas in intertidal zones on the Lower Normandy coast (France) to determine the most common species with the highest bioaccumulation capacity. Results are compared with published data on blue mussels Mytilus edulis from the Réseau d'Observation de la Contamination Chimique biomonitoring network. A total of 720 sponge samples were collected to assess species richness. Samples were analysed for metal concentrations by flame-mode atomic absorption spectrometry. Analyses of polycyclic aromatic hydrocarbon were sub-contracted. Species richness varies according to the water mass concerned. The most common species in the study area showing the highest bioconcentration in its soft tissues is Hymeniacidon perlevis, which contains about 20 times the zinc, 44 times the copper and 16 times the fluoranthene levels found in mussels. The variability of contaminant concentrations in H. perlevis is also systematically higher than those in mussels. The results obtained for this sponge closely reflect the heterogeneous distribution of contaminants. This study demonstrates that H. perlevis has a much higher capacity to accumulate in situ contaminants than the blue mussel M. edulis. H. perlevis meets all the requirements of a good bioindicator suitable for use in an integrated monitoring programme. In the near future, controlled cultivation of H. perlevis will allow us to produce sufficient quantities of this species to carry out ecotoxicological tests and in situ biomonitoring by caging.
Mostrar más [+] Menos [-]Identification and quantitative detection of Legionella spp. in various aquatic environments by real-time PCR assay
2013
Kao, Po-Min | Tung, Min-Che | Hsu, Bing-Mu | Chiu, Yi-Chou | She, Cheng-Yu | Shen, Shumin | Huang, Youli | Huang, Wen-Chien
In this study, a SYBR green quantitative real-time PCR was developed to quantify and detect the Legionella spp. in various environmental water samples. The water samples were taken from watershed, water treatment plant, and thermal spring area in Taiwan. Legionella was detected in 13.6 % (24/176), and the detection rate for river water, raw drinking water, and thermal spring water was 10, 21.4, and 16.6 %, respectively. Using real-time PCR, concentration of Legionella spp. in detected samples ranged between 9.75 × 10(4) and 3.47 × 10(5) cells/L in river water, 6.92 × 10(4) and 4.29 × 10(5) cells/L in raw drinking water, and 5.71 × 10(4) and 2.12 × 10(6) cells/L for thermal spring water samples. The identified species included Legionella pneumophila (20.8 %), Legionella jordanis (4.2 %), Legionella nautarum (4.2 %), Legionella sp. (4.2 %), and uncultured Legionella sp. (66.6 %). The presence of L. pneumophila in aquatic environments suggested a potential public health threat that must be further examined.
Mostrar más [+] Menos [-]Impact of sewage sludge spreading on nickel mobility in a calcareous soil: adsorption–desorption through column experiments
2013
Mamindy-Pajany, Yannick | Sayen, Stéphanie | Guillon, Emmanuel
A soil column adsorption–desorption study was performed on an agricultural calcareous soil to determine the impact of sewage sludge spreading on nickel mobility. Ni adsorption experiments were followed by desorption tests involving the following liquid extractants: water, calcium (100 mg/L), oxalic acid (525 mg/L equivalent to 100 mg carbon/L), and sludge extracts (0.5 and 2.5 g/L). Desorption tests were also conducted after sewage sludge spreading at three application rates (30, 75, and 150 t/ha). According to the breakthrough curve, Ni adsorption was irreversible and occurred mainly through interactions with calcite surface sites. Nickel desorption from the soil column was promoted in presence of significant dissolved organic carbon (DOC) concentration as observed with oxalic acid elution and sludge extract at 2.5 g/L. In sludge-amended soil columns, the maximum Ni levels occurred in first pore volumes, and they were positively correlated to the sludge application rate. The presence of DOC in leaching waters was the main factor controlling Ni desorption from the sludge-amended soil columns. This finding implies that DOC generated by sludge applied on calcareous soils might facilitate the leaching of Ni due to the formation of soluble Ni–organic complexes. Thus, sludge application can have potential environmental impacts in calcareous soils, since it promotes nickel transport by decreasing Ni retention by soil components.
Mostrar más [+] Menos [-]Effects of silicon and copper on bamboo grown hydroponically
2013
Collin, Blanche | Doelsch, Emmanuel | Keller, Catherine | Panfili, Frédéric | Meunier, Jean-Dominique
Due to its high growth rate and biomass production, bamboo has recently been proven to be useful in wastewater treatment. Bamboo accumulates high silicon (Si) levels in its tissues, which may improve its development and tolerance to metal toxicity. This study investigates the effect of Si supplementation on bamboo growth and copper (Cu) sensitivity. An 8-month hydroponic culture of bamboo Gigantocloa sp. "Malay Dwarf " was performed. The bamboo plants were first submitted to a range of Si supplementation (0-1.5 mM). After 6 months, a potentially toxic Cu concentration of 1.5 μM Cu(2+) was added. Contrary to many studies on other plants, bamboo growth did not depend on Si levels even though it absorbed Si up to 218 mg g(-1) in leaves. The absorption of Cu by bamboo plants was not altered by the Si supplementation; Cu accumulated mainly in roots (131 mg kg(-1)), but was also found in leaves (16.6 mg kg(-1)) and stems (9.8 mg kg(-1)). Copper addition did not induce any toxicity symptoms. The different Cu and Si absorption mechanisms may partially explain why Si did not influence Cu repartition and concentration in bamboo. Given the high biomass and its absorption capacity, bamboo could potentially tolerate and accumulate high Cu concentrations making this plant useful for wastewater treatment.
Mostrar más [+] Menos [-]A novel source of biofertilizer from feather biomass for banana cultivation
2013
Gurav, Ranjit G. | Jadhav, Jyoti P.
Feather waste is a promising protein biomass available as by-product from poultry processing was found to be rich in peptides, amino acids, and minerals like nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, zinc, and copper. Soil and foliar application of these products, besides representing a sustainable solution to the problem of feather disposal, may also represent an effective strategy to tackle the environmental effluence. As a consequence, they were also found to be very attractive in elevating the protein, amino acids, reducing sugar, total chlorophyll, and proline content of plants. On the other side, fertilizing effect enhanced the antioxidant potential of banana fruit which was assessed using 2, 2-diphenyl-1-picrylhydrazyl, ferric reducing/antioxidant power, and N, N-dimethyl-p-phenylendiamine. This was associated with considerably higher antioxidant contents like total phenolics and flavonoids. Therefore, the application of this organic amendment could promote and improve the agro-ecosystem, human health; soil biological activities, and at the same time enhance the production of plant or products rich in bioactive substances.
Mostrar más [+] Menos [-]Biodegradation and removal of 3,4-dichloroaniline by Chlorella pyrenoidosa based on liquid chromatography-electrospray ionization-mass spectrometry
2013
Wang, Shujuan | Poon, Karen | Cai, Zongwei
3,4-Dichloroaniline (3,4-DCA), widely used in the synthesis of dyes, textile and herbicides, is toxic to living organisms. The purpose of this study was to investigate the capability of green algae in degrading and removing 3,4-DCA in water. An environmentally ubiquitous green alga Chlorella pyrenoidosa was isolated from fresh aquatic environment. Then unicellular alga was incubated with 3,4-DCA at a concentration of 4.6 μg/ mL in water. The residual concentration of 3,4-DCA in the medium and the metabolites were analyzed. A removal percentage of 78.4 % was obtained over a 7-day period. Two major metabolites with less toxicity were identified as 3,4-dichloroformanilide and 3,4-dichloroacetanilide from the liquid chromatography-electrospray ionization-mass spectrometry analysis. The application of microalga C. pyrenoidosa may have potential for removing the environmental pollutant in aquatic environment.
Mostrar más [+] Menos [-]Using diatom indices for water quality assessment in a subtropical river, China
2013
Tan, Xiang | Sheldon, Fran | Bunn, Stuart E. | Zhang, Quanfa
Diatoms have been regularly used as bioindicators to assess water quality of surface waters. However, diatom-based indices developed for a specific geographic region may not be appropriate elsewhere. We sampled benthic diatom assemblages in the upper Han River, a subtropical river in China, to evaluate applicability of 14 diatom-based indices used worldwide for water quality assessment. A total of 194 taxa from 31 genera were identified in the dry season and 139 taxa from 23 genera in the wet season. During the dry season, significant relationships were found for all but one of the diatom-based indices (Index Diatom Artois–Picardie) with one or more physical and chemical variables including nutrients and ion concentrations in river waters. The Biological Diatom Index (IBD) and diatom-based eutrophication/pollution index (EPI-D) were strongly related to trophic status and ionic content, while Watanabe’s Index was related to organic pollution and conductivity. Yet, the diatom indices showed weak relationships with physical and chemical variables during the wet season. It suggests that diatom-based indices developed in Europe can be applied with confidence as bioindicators of water quality in subtropical rivers of China, at least during base-flow conditions.
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