Responses of Microalgae Isochrysis galbana Parke, 1949, on Copper Oxide Nanoparticles and Copper Ions Impact Under Short- and Long-term Cultivation

The primary patterns of alterations in the primnesiophyte microalga Isochrysis galbana’s morphological, structural-functional, fluorescence, and cytometric characteristics under the impact of various concentrations of copper in the ionic and nanoform have been investigated. It has been demonstrated that copper in the form of nanoxide is approximately 10 times less hazardous to microalgae than copper in its ionic form. The two types of copper under investigation had similar effects on cells, including growth inhibition, a reduction in the effectiveness of the photosynthetic apparatus, an increase in the volume and intracellular concentration of chlorophyll a , an increase in the production of reactive oxygen species, and a decrease in the activity of the enzyme esterase. The surface of the cell wall is significantly affected mechanically by CuO NPs, which is a distinguishing characteristic. The final density of cultures in the stationary growth phase depended on the introduced concentration of the contaminant and, naturally, decreased with an increase in the initial copper content in the medium. At sublethal concentrations of pollutants, I. galbana culture was divided into two subpopulations of cells with different functional activities: sensitive and resistant to copper. The latter are able to ensure the survival and subsequent recovery of the I. galbana population under favorable growth conditions.