Bacteria Offers Hope in Battle Against Persistent PFAS Chemicals

In a significant development for environmental science, researchers have identified a strain of bacteria that shows great promise in the ongoing struggle against per- and polyfluoroalkyl substances (PFAS). Known as “forever chemicals” due to their stubborn persistence in the environment, PFAS have long been a source of concern for public health and ecological balance. Traditional methods of remediation often involve adsorption and containment, but scientists are increasingly looking to microscopic allies to break these chemicals down into less harmful components.

Bacteria’s Role in PFAS Remediation

Unlike traditional cleanup methods, certain bacteria demonstrate the unique ability to break the strong chemical bonds that make PFAS so resilient. A team from the University at Buffalo (UB), led by Diana Aga, SUNY Distinguished Professor and Henry M. Woodburn Chair in Chemistry, has discovered a strain of bacteria called Labrys portucalensis F11 that can degrade at least three types of PFAS. What’s particularly exciting about this discovery is that F11 can also tackle some of the hazardous byproducts formed during the degradation process.

Breakthrough Findings

The study, recently published in Science of the Total Environment, demonstrated that the F11 bacteria can metabolize over 90% of perfluorooctane sulfonic acid (PFOS) after a 100-day exposure period. PFOS is among the most commonly detected PFAS compounds and was recently classified as hazardous by the U.S. Environmental Protection Agency.

Beyond PFOS, the F11 strain significantly reduced levels of two other PFAS chemicals: 5:3 fluorotelomer carboxylic acid by 58% and 6:2 fluorotelomer sulfonate by 21% within the same timeframe.

The Mechanics of Bacterial Degradation

The key to F11’s effectiveness lies in its unique metabolic pathways. Most bacteria struggle to break the carbon-fluorine bond, which is integral to PFAS’ stability. However, the F11 strain has evolved to detach the fluorine atoms and utilize the carbon as an energy source, effectively transforming these hazardous compounds into more manageable substances.

“F11 is essentially cutting off the fluorine and using the carbon as food,” Aga explains. “This ability to redirect the carbon-fluorine bond represents a significant breakthrough in our understanding of PFAS degradation and opens new possibilities for their removal from contaminated environments.”

Addressing Metabolites

Previous research on PFAS-degrading bacteria often neglected the metabolites, or breakdown products, formed during the process. The F11 study, however, pays special attention to these substances. Remarkably, F11 could even remove fluorine from some of these metabolites or break them down to undetectable levels, further reducing environmental risks.

“Traditional methods often overlook the metabolites, which can sometimes be just as dangerous as the original compounds,” Aga notes. “By accounting for these smaller molecules, we gain a more comprehensive understanding of F11’s potential as a PFAS remediation tool.”

Challenges and Future Directions

While the F11 strain shows great promise, some challenges remain. The degradation process took 100 days under laboratory conditions with no alternative carbon sources available. To make this technology viable for real-world applications, researchers need to explore ways to accelerate F11’s degradation of PFAS.

“We’re investigating the impact of introducing alternative carbon sources, but we must strike a balance,” Aga explains. “The bacteria need nutrients to grow, but too many alternatives might reduce their incentive to process PFAS.”

Further studies will also explore the potential deployment of F11 in PFAS-contaminated water and soil. One promising approach involves bioaugmentation, which entails introducing specific bacterial strains into contaminated sites to enhance remediation efforts. This technique could significantly improve the cleanup of PFAS-affected environments.

The Importance of PFAS Remediation

PFAS are synthetic chemicals widely used in various industries since the 1950s, from nonstick cookware to firefighting foams. Despite their numerous applications, PFAS pose significant risks to human health and the environment due to their resistance to degradation. Exposure to PFAS has been linked to a variety of health issues, including cancer, liver damage, and autoimmune disorders.

Thanks to the innovative work of researchers like Diana Aga and her team, there is renewed hope for effective PFAS remediation. By harnessing the metabolic capabilities of bacteria, scientists can potentially address the lingering presence of these “forever chemicals” and mitigate their harmful effects on our planet.

Conclusion

The discovery of Labrys portucalensis F11 marks a significant step forward in the fight against PFAS contamination. With its unique ability to degrade multiple PFAS compounds and metabolites, F11 represents a promising new tool in environmental remediation efforts. While there is still much work to be done to optimize its effectiveness, this breakthrough highlights the potential of microscopic solutions to some of our most pressing environmental challenges.

Stay tuned for future developments in PFAS remediation and other advances in environmental science. Join us in the conversation by leaving your thoughts and questions below!