Genotoxicity of organic pollutants in source of drinking water on microalga Euglena gracilis

State Key Laboratory of Pollution Control and Resource Reuse and School of the Environment, Nanjing University, 22 Hankou Road, 210093 Nanjing, China.
Ecotoxicology (Impact Factor: 2.71). 07/2009; 18(6):669-76. DOI: 10.1007/s10646-009-0343-0
Source: PubMed


The potential toxicities of organic pollutants in the drinking water source at Meiliang Bay of Lake Taihu were investigated by comet assay and antioxidant enzyme approach on microalgae Euglena gracilis. The organic extracts of the water samples could induce DNA damage on microalgae cells. Statistically significant differences (P < 0.05) were observed at groups of 0.3x, 3x and 10x concentrations compared with the control and a solvent control (DMSO). The organic extracts also affected antioxidant enzyme activity and induced lipid peroxidation in the microalga. In the high dose group, there was an obvious increase in SOD content (P < 0.05). The results suggest that the concentrated organics from water sample extracts have adversary effects on E. gracilis and could possibly damage the ecosystem.

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Available from: Changwei Hu, Jan 01, 2014
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    • "As a unicellular flagellated protist, Euglena gracilis is an excellent model for research in eukaryotic cell biology (Foltí nová and Grones, 1997). In addition, E. gracilis has been used as a model organism to study the ecotoxicity or genotoxicity of various environmental stressors, such as organic pollutants (Li et al., 2009) and nanoparticles (Brayner et al., 2011). "
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    ABSTRACT: Potential environmental risks posed by nanomaterials increase with their extensive production and application. As a newly emerging carbon material, graphene oxide (GO) exhibits excellent electrochemical properties and has promising applications in many areas. However, the ecotoxicity of GO to organisms, especially aquatic organisms, remains poorly understood. Accordingly, this study examined the toxicity of GO with protozoa Euglena gracilis as test organism. Growth inhibition test was initially performed to investigate acute toxic effects. Protozoa were subsequently exposed to GO ranging from 0.5mgL(-1) to 5mgL(-1) for 10d. The growth, photosynthetic pigment content, activities of antioxidant enzymes, ultrastructure of the protozoa, as well as the shading effect of GO, were analyzed to determine the mechanism of the toxicity effect. Results showed that the 96h EC50 value of GO in E. gracilis was 3.76±0.74mgL(-1). GO at a concentration of 2.5mgL(-1) exerted significant (P<0.01) adverse effects on the organism. These effects were evidenced by the inhibition of growth and the enhancement of malondialdehyde content and antioxidant enzyme activities. Shading effect and oxidative stress may be responsible for GO toxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jun 2015 · Chemosphere
    • "E. gracilis has been used as a model for studying the biological effects of environmental stressors especially heavy metals [13] [14]. Very recent studies used E. gracilis to monitor the genotoxicity of water contaminants [15] and evaluate the ecotoxicological effects of industrial wastewater [16] [17]. "
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    ABSTRACT: Abstract BTEX is a group of volatile organic compounds consisting of benzene, toluene, ethylbenzene and xylenes. Environmental contamination of BTEX can occur in the groundwater with their effects on the aquatic organisms and ecosystem being sparsely studied. The aim of this study was to evaluate the toxic effects of individual and mixed BTEX on Euglena gracilis (E. gracilis). We examined the growth rate, morphological changes and chlorophyll contents in E. gracilis Z and its mutant SMZ cells treated with single and mixture of BTEX. BTEX induced morphological change, formation of lipofuscin, and decreased chlorophyll content of E. gracilis Z in a dose response manner. The toxicity of individual BTEX on cell growth and chlorophyll inhibition is in the order of xylenes > ethylbenzene > toluene > benzene. SMZ was found more sensitive to BTEX than Z at much lower concentrations between 0.005 and 5 μM. The combined effect of mixed BTEX on chlorophyll contents was shown to be concentration addition (CA). Results from this study suggested that E. gracilis could be a suitable model for monitoring BTEX in the groundwater and predicting the combined effects on aqueous ecosystem. Keywords: Volatile organic compounds (VOCs); Cell toxicology; Chlorophyll; Mixed contaminants; Combined effects
    No preview · Article · Oct 2014 · Journal of Hazardous Materials
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    • "The comet assay with E. gracilis was performed following methods described by Singh et al. (1988), Aoyama et al. (2003) and Li et al. (2009) with some modifications. The slides were examined with a fluorescent microscope (BX41, Olympus, Japan). "
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    ABSTRACT: The microalga Euglena was selected as a bioindicator for determining genotoxicity potencies of organic pollutants in Meiliang Bay of Taihu Lake, Jiangsu, China among seasons in 2008. Several methods, including the comet assay to determine breaks in DNA and quantification of antioxidant enzymes were applied to characterize genotoxic effects of organic extracts of water from Taihu Lake on the flagellated, microalga Euglena gracilis. Contents of photosynthetic pigments, including Chl a, Chl b and carotenoid pigments were inversely proportion to concentrations of organic extracts to which E. gracilis was exposed. Organic extracts of Taihu Lake water also affected activities of superoxide dismutase (SOD) and peroxidase (POD) of E. gracilis. There were no statistically significant differences in SOD activities among seasons except in June but significant differences in POD activities were observed among all seasons. The metrics of DNA fragmentation in the alkaline unwinding assay (Comet assay), olive tail moment (OTM) and tail moment (TM), used as measurement endpoints during the genotoxicity assay were both greater when E. gracilis was exposed to organic of water collected from Taihu Lake among four seasons. It is indicated that the comet assay was useful for determining effects of constituents of organic extracts of water on E. gracilis and this assay was effective as an early warning to organic pollutants.
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