A common bacterium found in the soils of New Jersey and similar climates could be effective in breaking down harmful pollutants that pose considerable threats to the environment and human health, new research suggests.
In laboratory tests, Acidimicrobium bacterium A6 successfully broke down up to 60 percent of per- and polyfluoroalkyl substances (PFAS), a group of man-made chemicals used around the world in a variety of products, from non-stick pans to food packaging. PFAS are difficult to break down both in the environment and in the human body, and exposure to the chemicals can have adverse human health effects, including low infant birth weights, cancer, and thyroid hormone disruption, notes the US Environmental Protection Agency (EPA). The substance is long-lived and difficult to remove from soil and groundwater, prompting the EPA to launch a research endeavor into how the chemicals can impact drinking water.
Princeton researchers first came across the bacteria years ago when they noticed it broke down ammonium – a key component of PFAS – when it was found in acidic, iron-rich soils in New Jersey’s wetlands. They dubbed it the Feammox process but found it can only occur in the presence of iron, which made growing and cultivating the bacteria a difficult and lengthy project.
Isolating the bacterium required some clever thinking by researchers to outfit an electric anode (a fancy word for a metal rod) to react with the bacteria and allow it to grow so that the team could sequence its genetic information.
Writing in the journal Environmental Science and Technology, the team took their research to the next level. Two different types of PFAS were stored in lab vials with Acidimicrobium bacterium A6 and observed over the course of 100 days. They found it removed up to 60 percent of contaminants and released the same amount of fluoride in the process.
Though exciting, the researchers are quick to caution that there is more work to be done.
"This is a proof of concept," said study co-author Peter Jaffe in a statement. "We would like to get the removal higher, and then go and test it in the field."
The team notes that longer incubation periods may result in higher levels of removal and plan on conducting future tests with varying conditions in the future.