Investigation the toxicity of silver nanoparticles on the growth, viability, and pigment content of chlorella vulgaris

Nanotechnology is one of the emerging and advanced sciences that has been highly developed in recent years and has caused environmental pollution. Therefore, in this study, the toxicity of silver nanoparticles on the green alga Chlorella vulgaris was investigated. Chlorella vulgaris cells were exposed to concentrations of 0, 0.005, 0.001, 0.05, 0.01, 0.5 and 0.1 mg / l silver nanoparticles over a period of 96 hours. The results showed that the cell density of Chlorella vulgaris decreased with increasing concentration of silver nanoparticles compared to the control group and even at the lowest concentration of 0.005 mg / l caused the cell growth inhibition (p<0.05). With increasing concentration of silver nanoparticles, the survival rate decreased compared to the control group and did not change during the 96-hour period. The amount of chlorophyll a, b and total pigments in the concentrations of 0.05 and 0.1 mg / l and the duration of 24 hours were the highest, but the values ​​of carotenoids showed the highest in 96 h and the concentration of 0.01 mg / l of silver nanoparticles. Silver nanoparticles are highly toxic to Chlorella vulgaris and if silver nanoparticles are released, the production, survival and chlorophyll content of this microalgae, as one of the main primary producers in freshwater ecosystems, is damaged.