As defined by the USEPA, bioremediation is an engineered technology that modifies environmental conditions (physical, chemical, biochemical, or microbiological) to encourage microorganisms to destroy or detoxify organic and inorganic contaminants in the environment. Environmental scientists and engineers currently utilize a wide range of organisms from plants, bacteria, to even fungi for these purposes.
One class of contaminants that has garnered a lot of attention in recent years in the field of environmental remediation is Per-and polyfluoroalkyl substances (PFAS). Utilized in a plethora of industries around the globe and United States since the 1940s1, these chemicals are especially persistent in the food web due to their possession of one of the strongest single bonds in organic chemistry: the carbon-fluorine bond2. Showing toxicity to biological life which causes reproductive, developmental, and immunological effects in animals, the International Agency for Research on Cancer has designated the most common PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), as possible carcinogens1. With improved analytical methods for the identification of these substances, we will most likely observe an increase in hot spots of drinking water contamination3. New Jersey is ahead of the national curve in the United States for the identification of PFAS in its waters and, consequently, in the implementation of regulations4. However, last year researchers may have uncovered a bit of hope for PFAS remediation in our own backyard.
In our second entry in JM Sorge’s Bioremediation Spotlight, we look to Professor Peter Jaffé and Associate Research Scholar Dr. Shan Huang, researchers at Princeton University’s Civil and Environmental Engineering Department. Prior research gave these scientists insight into their current findings when they noticed a chemical reaction that broke down ammonium ions in low-oxygen, acidic soils. The Assunpink Wildlife Management area in Allentown, New Jersey held the key to unlocking what researchers called the Feammox process: a microorganism named Acidimicrobium sp. strain A6. Astonishingly, this bacterium demonstrated an ability to break down pollutants such as trichloroethylene (TCE) and perchloroethylene (PCE). This led scientists to speculate that these microorganisms could break the tough chemical bonds between carbon and fluorine in PFAS5.
Jaffé and Huang’s research reports that, in a 100-day incubation period in the lab, the wetland bacterium removed the fluorine atoms from up to 60% of PFOA and PFOS, rendering the substances harmless. This has significant implications that sites contaminated with PFAS could potentially be cleaned up utilizing bioremediation. This also brings constructed wetlands containing acidic, high iron soils into view as potential bioremediating habitats5.
Acidimicrobium A6 survives well in oxygen poor conditions, which are of benefit to consultants concerned with soil and groundwater remediation that involves expensive aeration practices6. Compared to other physical and chemical treatments, bioremediation has the potential to be implemented in place more easily and cheaply.
Despite it being a slow process, the research is potentially transformative, for the first time demonstrating that PFAS can be biodegraded, says William Cooper, an environmental chemist at the University of California, Irvine7. Dr. Jaffé has already begun further research funded by the U.S. Department of Defense. On–the–ground applications of these findings may take some time to develop but, if achieved, this New Jersey microbe could eat through significant amounts of PFAS in months to a year. Jaffé notes, “For what is termed a ‘forever chemical’, 100 days to one year is fine.”4
JM Sorge will be eagerly awaiting further research from Jaffé’s team surrounding this and other remediation technologies.
For more on Dr. Jaffé and Dr. Huang’s research visit:
For the published article visit:
2 O’Hagan D. Understanding organofluorine chemistry. An introduction to the C-F bond. Chem Soc Rev. 2008 Feb;37(2):308-19. doi: 10.1039/b711844a. Epub 2007 Oct 17. PMID: 18197347.