Viability of the Microalgae Thalassiosira Weissflogii and Prorocentrum Cordatum to Titanium Nanoparticles

According to the results of the experimental study, it was found that the addition of titanium dioxide nanoparticles does not lead to changes in morphological, structural, functional and fluorescent indices of the diatom Thalassiosira weissflogii and the dinophyte Prorocentrum cordatum in the concentration range of 0.5–6.2 mg L⁻¹. At the highest concentration of the pollutant (6.2 mg L⁻¹), no decrease in the enzymatic activity (FDA fluorescence characterizes the level of metabolic activity of cells) of algae and no increase in the production of reactive oxygen (D2CFH-DA fluorescence, reflects ROS production in cells) species were observed after 72 h of cultivation. The efficiency of the cell photosynthetic apparatus (Fv/Fm) and relative electron transport rate (rETR) were maintained at a high relatively constant level for algae growing under high NPs TiO₂ concentration. Scanning electron and light microscopy micrographs also showed the absence of morphological changes in T. weissflogii and P. cordatum cells and no significant cell wall deformation when exposed to NPs TiO₂. It is suggested that probably the absence of adsorption of titanium dioxide nanoparticles on the surface of T. weissflogii and P. cordatum cells is associated with the physicochemical properties of TiO₂ NPs, in particular, with their surface charge.