| Autor: |
Devars, Silvia, Rodríguez-Zavala, José, Moreno-Sánchez, Rafael |
| Předmět: |
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| Zdroj: |
Water, Air & Soil Pollution; Mar2011, Vol. 216 Issue 1-4, p51-57, 7p |
| Abstrakt: |
Toxicity of Hg was determined in two strains of Euglena gracilis var. bacillaris: the wild-type (B) and a streptomycin-resistant strain (Sm). Cells were cultured under 12-h dark/12-h light regime or under continuous darkness. In the dark/light cultures, cellular growth was severely diminished in the B strain by Hg, whereas only a slight decrease was attained in the Sm strain; Hg also affected the photosynthetic and respiratory activities of the B strain, but not those of Sm strain. Under continuous darkness, cellular growth of both strains was lower than under dark/light cycles, but it was inhibited by Hg to a much lesser extent. Cell culture by 5 days under continuous dark or by 8 days of dark/light cycles resulted in a higher intracellular content of mercury in B strain than in Sm strain. In contrast, in both culture conditions, the fraction of mercury removed from medium by B strain was lower than that attained by Sm strain, whereas the ability to bio-transform (reduce) Hg was two times higher in the mutant strain. The results suggested that Sm strain cells acquired an ability to remove Hg from the medium, which was not associated to accumulation and which conferred protection against mercury. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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