Impact of copper oxide nanoparticles on the physiology of different microalgal species

Abstract

Sublethal concentrations of CuO NPs were added to the medium in the amounts of 3000, 2500, 1000, and 400μg L−1, respectively, to determine the main trends of changes in the morpho — physiological, biochemical and structural indicators of the microalgae Dunaliella salina (Teod.), Isochrysis galbana Parke, 1949; Thalassiosira weissflogii (Grunow) G.A. Fryxell & Hasle, 1977; and Prorocentrum cordatum (Ostenfeld) Dodge, 1975. Nearly every aspect of algae physiology is impacted by NPs, which also cause changes in the integrity of cell wall, an increase in cell volume, and a rise in the number of dead or inactive cells in culture. Reactive oxygen species production rises, metabolic activity of cells falls, mitochondrial membranes depolarize. The four studied species — D. salina, I. galbana, Th. weissflogii and P. cordatum — are arranged in a row, starting with the most resistant to the effects of NPs CuO. The 2% release of Cu2+ copper ions from CuO NPs is not the main cause of the harmful effects of NPs on cells. The mechanical action of CuO NPs, which damages cell membranes and aggregates NPs on the algae’s surface, is primarily responsible for their inhibitory effect on algae. P. cordatum and Th. weissflogii, which have dense shells in comparison to D. salina and I. galbana with ultrathin cell membranes, did not produce cells that were more resilient to the effects of CuO NPs. The photosynthetic system of the tested algae species exhibited high functional tolerance to the impacts of copper oxide nanoparticles. Fluorescent measures (Fv/Fm, rETR) can be used to determine a pollutant’s capacity to obliterate microalgae. It is shown that there is a connection between the unrestrained increase in CuO NPs concentration in water and the potential harm to the primary production of aquatic ecosystems.