Researchers at the University of Nebraska–Lincoln have discovered that the common photosynthetic bacterium Rhodopseudomonas palustris can draw perfluorooctanoic acid, a persistent PFAS chemical, into its cell membrane. In lab experiments, the microbe removed about 44% of the chemical over 20 days, though much of it later returned to the environment. The findings, published in Environmental Science: Advances, suggest potential for engineering microbes to combat PFAS pollution.
Scientists Rajib Saha and Nirupam Aich led a study examining how Rhodopseudomonas palustris interacts with perfluorooctanoic acid (PFOA), a highly resistant member of the PFAS family known as forever chemicals. These compounds persist in soil and water, posing risks to water quality and public health. The research, detailed in the journal Environmental Science: Advances, revealed that the bacterium absorbs PFOA into its cell membrane, with the behavior evolving over time.
In controlled lab tests, R. palustris removed approximately 44% of PFOA from its surroundings within 20 days. However, much of the absorbed chemical was released back into the environment when the bacterial cells broke apart, highlighting both the promise and limitations of microbial approaches for PFAS cleanup. Existing treatments for these pollutants are often costly and energy-intensive, making biological strategies an attractive alternative if further developed.
"While R. palustris didn't completely degrade the chemical, our findings suggest a stepwise mechanism where the bacterium may initially trap PFOA in its membranes," said Saha, Richard L. and Carol S. McNeel Associate Professor. "This gives us a foundation to explore future genetic or systems biology interventions that could improve retention or even enable biotransformation."
The collaboration combined Saha's biological experiments with Aich's expertise in PFAS detection. "This kind of collaboration is exactly what's needed to address complex environmental challenges," Aich, Richard L. McNeel Associate Professor, noted. "By bringing together microbiology, chemical engineering, and environmental analytical science, we're gaining a more complete picture of how to tackle PFAS pollution with biological tools."
Doctoral candidates Mark Kathol from the Saha Lab and Anika Azme from the Aich Lab served as co-first authors, with the work supported by the Layman Award and Nebraska Collaboration Initiative Grant. The teams plan further studies on microbial engineering and synthetic biology to enhance PFAS degradation.