Combining hydrogen peroxide addition with sunlight regulation to control algal blooms
In: Environmental science and pollution research: ESPR, Band 25, Heft 3, S. 2239-2247
ISSN: 1614-7499
9 Ergebnisse
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In: Environmental science and pollution research: ESPR, Band 25, Heft 3, S. 2239-2247
ISSN: 1614-7499
In: Ecotoxicology and environmental safety: EES ; official journal of the International Society of Ecotoxicology and Environmental safety, Band 249, S. 114429
ISSN: 1090-2414
In: Environmental science and pollution research: ESPR, Band 22, Heft 14, S. 10636-10646
ISSN: 1614-7499
In: Environmental science and pollution research: ESPR, Band 22, Heft 7, S. 5491-5499
ISSN: 1614-7499
In: Ecotoxicology and environmental safety: EES ; official journal of the International Society of Ecotoxicology and Environmental safety, Band 73, Heft 7, S. 1804-1811
ISSN: 1090-2414
In: Environmental sciences Europe: ESEU, Band 31, Heft 1
ISSN: 2190-4715
Abstract
Background
Sensitivity differences to chemical pollutants in different phytoplankton species may potentially shape the community structure of phytoplankton. However, detailed information supporting the understanding of sensitivity variations between phytoplankton species is still limited.
Results
To investigate sensitivity differences between the cyanobacterium Microcystis aeruginosa, and the green alga Chlorella sp. to paraquat, multiple physiological parameters were measured and compared through acute and chronic toxicity assays. Early photosynthetic responses during acute toxicity assays showed that paraquat affects Photosynthesis System II energy fluxes in M. aeruginosa within 3 h of exposure, but not in Chlorella sp. After 5 h of cumulative exposure, an EC50 based on the maximum quantum yield for primary photochemistry of 0.54 mg L−1 was achieved and remained more or less constant, while the EC50 values for Chlorella fluctuated around 44.76 ± 3.13 mg L−1 after 24 h of exposure. During chronic 96 h exposure to paraquat, differences in antioxidant enzyme activities, reactive oxygen species (ROS) levels, and ultrastructure were observed in both M. aeruginosa and Chlorella sp. An increase in the intracellular levels of ROS and the number of plasma membrane damaged cells was observed in M. aeruginosa in the 0.2, 0.5, and 1.0 mg L−1 treatments (p < 0.01), but not for Chlorella. In addition, at an exposure level of 1.0 mg L−1, extensive disruption of cell structure was observed in M. aeruginosa. Conversely, little disarrangement of organelle structure was found in Chlorella sp.
Conclusion
These results confirm that paraquat is more toxic to M. aeruginosa than to Chlorella sp. The sensitivity differences between these two species (one a prokaryote and the other a eukaryote) to paraquat might be partially explained by the differences in cell structure (cell wall and photosynthetic structure), the enzymatic antioxidant system, and the physiological vulnerability. The multiple physiological endpoint analysis approach used in the current study provides more detailed information for understanding the mechanisms of sensitivity variation between these phytoplankton species.
In: Environmental science and pollution research: ESPR, Band 23, Heft 15, S. 15616-15626
ISSN: 1614-7499
In: Environmental science and pollution research: ESPR, Band 23, Heft 8, S. 7288-7297
ISSN: 1614-7499
In: Environmental science and pollution research: ESPR, Band 22, Heft 7, S. 5531-5537
ISSN: 1614-7499