Assessment of SnO2 nanoparticles' impact on local Pichoclorum atomus growth performance, cell morphology and metabolites content

Abstract

Oxide nanoparticles are among the most used nanomaterials and have received considerable attention over their potential ecological effects. Increasing investigations report toxicity of certain oxide nanoparticles, however, there are also studies showing opposite results, [1] highlighting the fact that these nanoparticles may differ in their toxicological effects, which depend on particle variety and size, test organism species, and test method. The current study investigates the ecotoxicity of SnO2 nanoparticles on a local marine algae isolate. Five different concentrations (1, 5, 25, 50 and 100mg/L) were tested and the culture was followed for 72h. Algae growth, morphology and metabolites were followed each 24h. The obtained data showed that the SnO2 presented a toxicity on the algae growth that was decreasing with the dose, with lower doses presenting more negative impacts than the higher doses. In parallel, the slow growth observed at 1-5 mg/L was explained by the dramatic damages caused by the SnO2 on the cell morphology, which was detected using the scanning electronic microscopy. Indeed, this low negative impact of higher concentrations of SnO2 (50-100mg/L) is explained by the high agglomeration of ten particles leading to reduced effect on the cell morphology and health. Furthermore, and in accordance with the morphological data, the metabolites analysis data revealed that SnO2 nanoparticles induced stress, which was manifested by an increase in the lipid content and decrease in the proteins, a metabolite that is involved in the algal growth. [1]: M. Heinlaan, A. Ivask, I. Blinova, H.C. Dubourguier, A. Kahru. Toxicity of nanosized and bulk ZnO, CuO and TiO2 to bacteria Vibrio fischeri and crustaceans Daphnia magna and Thamnocephalus platyurus. Chemosphere, 71 (2008), pp. 1308-1316.