Comparison of Physiological Changes in Euglena gracilis During Exposure to Heavy Metals of Heterotrophic and Autotrophic Cells

Navarro, Leticia; Torres-Márquez, M. Eugenia; González-Moreno, Sergio; Devars, Silvia; Hernández, Rosa Gabriela Reveles; Moreno‐Sánchez, Rafael

doi:10.1016/s0742-8413(96)00202-2

Cited by 30 publications

(30 citation statements)

References 23 publications

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“…No adjustment was made for the difference in U uptake by cells in each of the treatments, as this study did not address the bioavailability of the U that was in or on the cell. Previous studies demonstrating metal uptake by E. gracilis (Navarro et al 1997;Einicker-Lamas et al 2002), have shown the vacuoles of E. gracilis can play a detoxification role by accumulating metals. Thus, not all of the U stored within the cell may necessarily be bioavailable.…”

Section: Speciation Of Umentioning

confidence: 92%

Dissolved organic carbon reduces uranium toxicity to the unicellular eukaryote Euglena gracilis

Trenfield

Noller

et al. 2012

Ecotoxicology

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The influence of dissolved organic carbon (DOC), in the form of Suwannee River fulvic acid (SRFA), on uranium (U) toxicity to the unicellular eukaryote, Euglena gracilis (Z strain), was investigated at pH 6. In a background medium without SRFA, exposure of E. gracilis to 57 μg L(-1) U resulted in a 50% reduction in growth (IC(50)). The addition of 20 mg L(-1) DOC (as SRFA), reduced U toxicity 4 to 5-fold (IC(50) increased to 254 μg L(-1) U). This reduction in toxicity was also evident at more sensitive effect levels with a 10% reduction in growth (IC(10)) occurring at 5 μg L(-1) U in the background medium and at 17 μg L(-1) U in the SRFA medium, respectively. This amelioration of toxicity with the addition of SRFA was linked to a decrease in the bioavailability of U, with geochemical speciation modelling predicting 84% of U would be complexed by SRFA. The decrease in bioavailability of U in the presence of SRFA was also evident from the 11-14 fold reduction in the cellular concentration of U compared to that of E. gracilis in the background medium. Stepwise multiple linear regression analyses indicated that UO(2)(2+) alone explained 51% of the variation in measured U toxicity to E. gracilis. Preliminary U exposures to E. gracilis in the presence of a reactive oxygen species probe, suggest exposure to ≥60 μg L(-1) U may induce oxidative stress, but this endpoint was not considered to be a sensitive biological indicator.

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Section: Speciation Of Umentioning

confidence: 92%

Dissolved organic carbon reduces uranium toxicity to the unicellular eukaryote Euglena gracilis

Trenfield

Noller

et al. 2012

Ecotoxicology

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“…These characteristics make Euglena a model organism intermediate between plants and animals for use in ecotoxicology (Tahedl and Häder 2001). Euglena has extensively been used as a test organism for toxicity assessment of various chemicals like heavy metals and other biologically active compounds (Danilov and Ekelund 2001;Einicker-Lamas et al 2002;Ekelund 1993;Gajdosova and Reichrtova 1996;Navarroa et al 1997;Tahedl and Häder 2001). However, data regarding toxicity of pesticides to Euglena can hardly be found.…”

Section: Introductionmentioning

confidence: 99%

Comparative toxicity of the pesticides carbofuran and malathion to the freshwater flagellate Euglena gracilis

Azizullah

Richter

Häder³

2011

Ecotoxicology

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Pesticides are toxic chemicals used for agricultural as well as non-agricultural purposes. The toxicity of pesticides does not remain limited to the site of application but they also cause toxicity to non-target organisms in terrestrial as well as in aquatic environments. This study discusses the comparative toxicity of a carbamate (carbofuran) and an organophosphorus (malathion) pesticide to the freshwater flagellate Euglena gracilis during short- and long-term exposures. To evaluate the toxicity of the pesticides, different parameters of the flagellate, like cell density, motility, swimming velocity, cell shape, gravitactic orientation, photosynthetic efficiency, and concentration of light harvesting pigments, were used as end points. Carbofuran was found to be more toxic to E. gracilis than malathion and adversely affected almost all the tested parameters in short- and long-term experiments. The only significant adverse effect by malathion could be demonstrated on the swimming velocity of cells in short-term experiments. The adverse effects of the pesticides were more pronounced during short-term than during long-term exposure.

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“…It has been reported in numerous studies as a reliable organism for bioassays. Due to its high sensitivity to heavy metals and other biologically active compounds, E. gracilis has been proven to be a suitable organism for toxicity tests (Ekelund 1993;Gajdosova and Reichrtova 1996;Navarroa et al 1997;Danilov and Ekelund 2001b;Einicker-Lamas et al 2002). Euglena gracilis is powered by a single flagellum and orients itself in the water column using a number of external physical and chemical parameters such as light and gravity in search of a region optimal for growth and reproduction (Häder and Vogel 1990;Häder and Liu 1990;Häder et al 1999;.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity of various parameters in Euglena gracilis to short-term exposure to industrial wastewaters

Azizullah

Richter

Häder³

2011

J Appl Phycol

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Due to the presence of various potential pollutants industrial wastewaters pose considerable threats to natural waters and make it unfit for the aquatic biota. Analysis of wastewaters by chemical methods is a common practice; however, it does not reflect the toxic effects on living organism. Therefore, bioassessment is necessary for monitoring of wastewater quality. In the present study, the toxic effects of wastewater samples from different industries were evaluated using Euglena gracilis as a biotest organism. Various parameters of the freshwater flagellate E. gracilis like motility, swimming velocity, cell shape, gravitactic orientation (using the automatic biotest ECOTOX) and photosynthetic efficiency (using a pulse amplitude modulated fluorometer) were used as end points for toxicity assessment. In addition, the samples were analysed for some ecologically important physicochemical properties. With some exceptions, most of the physicochemical properties of the tested samples were within the acceptable range of national environmental quality standards for municipal and industrial effluents. However, all the water samples adversely affected different parameters in E. gracilis. This study led to the conclusion that different toxic substances present in wastewater, even at low concentrations, can be a possible threat to aquatic biota. The results of this study prove that ECOTOX is a sensitive, easy, and fast bioassay for monitoring of water and wastewater quality. Gravitactic orientation and cell compactness of E. gracilis were the most sensitive parameters to wastewater toxicity.

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Comparison of Physiological Changes in Euglena gracilis During Exposure to Heavy Metals of Heterotrophic and Autotrophic Cells

Cited by 30 publications

References 23 publications

Dissolved organic carbon reduces uranium toxicity to the unicellular eukaryote Euglena gracilis

Dissolved organic carbon reduces uranium toxicity to the unicellular eukaryote Euglena gracilis

Comparative toxicity of the pesticides carbofuran and malathion to the freshwater flagellate Euglena gracilis

Sensitivity of various parameters in Euglena gracilis to short-term exposure to industrial wastewaters

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