Computational simulation associated with biological effects of alkyl organophosphate flame retardants with different carbon chain lengths on Chlorella pyrenoidosa

The environmental safety of flame retardants has attracted growing attention. Alkyl organophosphorus flame retardants (OPFRs) have been prevalently applied, but the potential risk and the structure effects of different alkyl chain lengths OPFRs on aquatic microalgae remain unknown. This study investigated the biological response of five alkyl-OPFRs to Chlorella pyrenoidosa by computational simulation together with biological approaches. The reduced docking energy had a significantly positive correlation (R-2 = 0.9) with the cell inhibition alongside the incremental chain length of alkyl-OPFRs. Molecular docking simulations suggested that the toxicity of alkyl-OPFRs would be highly correlated to their molecular structures. Coincidently, the reactive oxygen species, superoxide dismutase and malondialdehyde were triggered by 85%, 92% and 155% (based on the control group), after exposure to the longest chain length tributyl phosphate (TBPC12), respectively. Furthermore, combining the ultrastructure scrutiny with the photosynthesis analysis, TBPC12 was also found to significantly inhibit the chlorophyll biosynthesis (43%) and restrain the photosynthetic efficiency (26%) when compared with the control group. Overall, this is the first study to comprehensively reveal the biological effects of different alkyl-OPFRs on microalgae via the combination of computational simulation and cellular responses, providing a novel insight into targeted predicting the aquatic ecological risks of OPFRs. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the biological response of different alkyl-OPFRs on aquatic microalgae through computational simulation and cellular responses, revealing a significant correlation between the toxicity of alkyl-OPFRs and their molecular structures.