Respiratory Toxicity of Azoxystrobin, Pyraclostrobin and Coumoxystrobin on Chlorella vulgaris

Azoxystrobin (AZ), pyraclostrobin (PYR) and coumoxystrobin (COU) exert negative impacts on Chlorella vulgaris. Thus, in this study, C. vulgaris was used to assess the respiratory toxicity of AZ, PYR and COU by determining the acute toxicity, complex III activity and ATP viability. The 96 h-EC50 values of AZ, PYR and COU for C. vulgaris were 1.85, 2.21 and 1.62 mg/L, respectively. AZ, PYR and COU exerted significant effects on complex III activity and ATP viability after exposure to 0.71, 1.01 and 1.08 mg/L of the fungicides. The binding potentials of AZ, PYR and COU toward ubiquinone were - 10.44, - 9.31 and - 12.98 kcal/mol, respectively, which had adverse effects on amino acids. These results provided new insight into the potential acute respiratory toxicity mechanisms of these strobilurin fungicides in algae.