A UC Riverside environmental engineering team has discovered specific bacterial species that can destroy certain kinds of “forever chemicals,” a step further toward low-cost treatments of contaminated drinking water sources.
The microorganisms belong to the genus Acetobacterium and they are commonly found in wastewater environments throughout the world.
Forever chemicals, also known as per- and polyfluoroalkyl substances or PFAS, are so named because they have stubbornly strong carbon-fluorine chemical bonds, which make them persistent in the environment.
The microorganisms discovered by UCR scientists and their collaborators can cleave those stubborn fluorine-to-carbon bonds, they reported Wednesday, July 17, in the journal Science Advances.
“This is the first discovery of a bacterium that can do reductive defluorination of PFAS structures,” said Yujie Men, corresponding author of the study and an associate professor at UCR’s Bourns College of Engineering in the Department of Chemical and Environmental Engineering.
Forever chemicals, also known as per- and polyfluoroalkyl substances or PFAS, are so named because they have stubbornly strong carbon-fluorine chemical bonds, which make them persistent in the environment
Using bacteria to treat groundwater is cost-effective because the microorganisms destroy pollutants before the water reaches wells. The process involves injecting the groundwater with the preferred bacteria species along with nutrients to increase their numbers.
Because PFAS compounds are linked to cancer and other human health maladies, the U.S. Environmental Protection Agency, or EPA, imposed water-quality limits earlier this year that restrict certain forever chemicals to only four parts per trillion in the nation’s tap water, spurring water providers to find PFAS cleanup solutions.
PFAS compounds came into widespread use in thousands of consumer products starting in the 1940s because of their ability to resist heat, water, and lipids. Examples of PFAS-containing products include fire suppressant foams, grease-resistant paper wrappers and containers such as microwave popcorn bags, pizza boxes, and candy wrappers; also, stain and water repellents used on carpets, upholstery, clothing, and other fabrics; according to the EPA.
The paper's title is “Electron-bifurcation and fluoride efflux systems in Acetobacterium spp. Drive defluorination of perfluorinated unsaturated carboxylic acids.” Yaochun Yu is the lead author. He was a visiting student scientist and a UCR post-doctoral scientist at UCR before joining the Swiss Federal Institute of Aquatic Science and Technology, or Eawag, in 2022.
