Metabolomics reveals the inhibition on phosphorus assimilation in Chlorella vulgaris F1068 exposed to AgNPs

Phosphorus removal by algae-based biotechnology can be achieved through algal assimilation, surface adsorption, or abiotic precipitation. However, there are still unavailable how these phosphorus removal processes were affected by nanoparticles in wastewater. Here, we employed a non-targeted metabolomic approach to reveal the impact of silver nanoparticles (AgNPs) on the phosphorus assimilation by a unicellular green alga Chlorella vulgaris F1068 (C. vulgaris F1068). Results showed that AgNPs mostly inhibited total phosphorus (TP) removal by the algal assimilation, with TP removal efficiency being reduced by 66.2% (with 0.20 mg/L AgNPs) of the control (without AgNPs). Metabolomics analysis also indicated that AgNPs disturbed metabolic responses related to phosphorus assimilation. AgNPs inhibited phospholipid metabolism which included inositol phosphate metabolism and phosphatidylinositol signaling system (downregulation of glycerol-3-phosphate and myo-inositol, as well as upregulation of serine). Metabolites related to phosphorus assimilation products were impacted through downregulation of guanine, glutamine, alanine, and aspartic acid, as well as upregulation of succinic acid, thereby impeding the algal assimilation of phosphorus. Moreover, perturbation of glutathionemetabolism induced by oxidative stress stimulated the alteration of membrane state (upregulation of glycine). These findings contribute to a molecular-scale perspective of nanoparticles on algae-based biotechnology in phosphorus removal. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study found that silver nanoparticles significantly inhibited the nitrogen-phosphorus absorption process of algae, resulting in a significant reduction in phosphorus removal efficiency. Metabolomics analysis showed that silver nanoparticles disrupted metabolic responses related to phosphorus absorption, affecting phospholipid metabolism and the generation of related metabolites, thereby impeding algae assimilation of phosphorus.