To Örebro University

Per- and polyfluorinated alkyl substances (PFASs) are environmental pollutants of global concern due to their persistence and widespread occurrence in humans, wildlife and the environment. These compounds have been extensively used in various commercial and industrial applications since the mid-1900. In 2009, perfluorooctane sulfonic acid (PFOS) was added to the Stockholm convention to protect humans and wildlife from harmful effects. In Sweden, severe PFAS contamination in drinking water has resulted in elevated blood PFAS concentrations in residents living in contaminated areas.

The present study evaluated microbial binding of PFASs was tested. The binding capacity was assessed in both live and dead Escherichia coli for various PFOS concentrations. The binding capacity of dead cells was higher (286-3324 μg/g of bacterial pellet) compared to live E. coli cells, showing a 5 – 7 fold lower binding capacity (38-675 μg/g of bacterial pellet). For PFOS, the affinity of branched isomers was similar to that of linear compounds. . Furthermore, other species of bacteria were tested for binding capacity of various mixtures of PFASs from both technical products and contaminated environmental waters, including Pseudomonas nitroreducens and Acidovorax delafieldii. After treatment, bacteria pellets were extracted and analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). Preliminary results indicate preferential binding for PFOS, the contaminant present in the highest concentration in both contaminated environmental water and spiked water of the sum of eleven PFASs recommended for analysis by the Swedish Food agency.

This study gives increased knowledge of microbial binding of perfluoroalkyl substances giving insight on PFAS transport in the environment and at different trophic levels. The phenomenon of microbial binding of PFASs could also be used to establish a more cost effective remediation of PFAS contaminated waters. Further, it could lead to increased understanding of toxicological effects of PFASs related to the gut microbiota.