Regarding the widespread use of titanium dioxide nanoparticles (TiO2NPs) in industry, many concerns have been raised about the risks of their potential release into aquatic ecosystems. Among the marine primary producers, Tetraselmis suecica is an ecologically important microalgae species used also as live feed in the shrimp culture industry. In the present study, the impacts of TiO2NPs on growth performance, photosynthetic pigments, lipid and protein content and its interaction with the cells of T. suecica were assessed. Based on the preliminary tests and OECD suggestion, concentrations of 5, 10, 50, 100, 200 and 400 mg/L TiO2NPs were applied to algal cells for 10 days. With increasing concentration, a decrease in T. suecica cell density was observed each day. TiO2NPs induced a half-maximal inhibitory concentration (IC50) of 106.26 mg/L on algal cells on the 3rd day. Chlorophyll a and b contents of the microalga decreased up to 56.08% and 52.74%, respectively following the exposure to TiO2NPs at 400 mg/L. TiO2NPs also decreased the algal contents of protein and lipid up to 7.21% and 50.64%, respectively at the highest concentration. Based on FTIR, FESEM with EDS and mapping analyses, the interaction of TiO2NPs with the T. suecica cells was revealed. The stocks of T. suecica could be damaged by the toxic effects of the released TiO2NPs affecting their application as live feed in mariculture.
|