Toxic effects and mechanisms of PFOA and its substitute GenX on the photosynthesis of Chlorella pyrenoidosa

Perfluorooctanoic acid (PFOA) and its substitute GenX are toxic chemicals that are widespread in the aquatic environment. However, there is little information about their toxicity mechanisms to aquatic organisms. In this study, Chlorella pyrenoidosa (C. pyrenoidosa) was treated with two concentrations (100 ng L-1 and 100 mu g L-1) of PFOA or GenX for 12 days. The results showed that these two concentrations of PFOA and GenX began to inhibit the growth of algae after 6 days of treatment, and the Chlorophyll content and photosynthetic activity of C. pyrenoidosa were also negatively affected by these two chemicals. The transcriptomic results indicated that most of the genes related to the photosynthetic metabolism of C. pyrenoidosa were down-regulated (in 100 ng L-1 treatment groups) on the 12th day. Besides, GenX and PFOA showed similar effects on algae photosynthesis including physical damage and metabolic disorders. According to this study, GenX might not be an ideal substitute for PFOA, and more attention should be paid on the management of emerging perfluoroalkyl substances. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study showed that both PFOA and GenX had negative effects on the growth, chlorophyll content, and photosynthetic activity of Chlorella pyrenoidosa. GenX may not be an ideal substitute for PFOA, and more attention should be paid to the management of emerging perfluoroalkyl substances.