Toxicity effects of copper on the marine diatom, Chaetoceros calcitrans
| Autor: | P.R. Anu, N.D. Don Xavier, P. R. Jayachandran, S. Bijoy Nandan |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Antioxidant medicine.medical_treatment Glutathione reductase chemistry.chemical_element 010501 environmental sciences Aquatic Science 01 natural sciences Superoxide dismutase medicine Extracellular Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences chemistry.chemical_classification Reactive oxygen species Ecology biology 010604 marine biology & hydrobiology Copper Enzyme assay chemistry Biochemistry Catalase biology.protein Animal Science and Zoology Nuclear chemistry |
| Zdroj: | Regional Studies in Marine Science. 8:498-504 |
| ISSN: | 2352-4855 |
| Popis: | Chaetoceros calcitrans is widely present as a dominant marine diatom in estuarine and coastal waters and therefore a potential target to the toxicity effects exerted by trace metals. Copper induced changes in growth and chlorophyll content in C. calcitrans were analysed. At all the concentrations above 320 μ g/L , the pro-oxidant copper caused a significant decrease in growth rate and chlorophyll concentration. The 96 h IC 50 value of copper based on percentage growth inhibition of C. calcitrans was 450 μ g/L . Copper concentration in the ambient water ranged from 2.38 to 608 μ g/L . The kinetics of copper accumulation in intracellular and extracellular compartments of the cells were determined and correlated with the corresponding antioxidant enzyme activity (catalase, superoxide dismutase, ascorbate peroxidase, glutathione reductase) on exposure to 50, 180 and 450 μ g Cu/L for 168 h. Copper adsorption to binding sites on the cell surface is relatively fast but further uptake into the cell is slow and considered as the rate limiting step. At sublethal concentrations as 50 and 180 μ g/L , intracellular accumulation of copper increased linearly over 168 h. The intracellular accumulation of copper showed significant positive correlation ( p 0.05 ) with catalase (CAT) and superoxide dismutase (SOD) activity when exposed to 50, 180 and 450 μ g/L . The reduction in the CAT and SOD activity on prolonged exposure to 450 μ g/L could be due to inactivation of enzyme as a result of higher reactive oxygen species (ROS) production. The extended period of exposure as in the present study resulted in sufficient accumulation of copper to activate CAT and SOD activity. The transient reduction in GR activity at 450 μ g/L could be due to the inactivation of enzyme by copper. The results suggest that slower uptake together with an efficient antioxidant system is to some extend contributes to the tolerance of the species to copper. |
| Databáze: | OpenAIRE |
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