University of Tennessee microbiologist to develop biofilter to clean-up toxic water

It is not an uncommon sight. Lakes and streams that were once safe to swim or fish in are now off limits to human contact. The threat is most likely a toxin -- called microcystin -- produced by blue-green algae.

Steven Wilhelm, microbiology professor at the University of Tennessee, Knoxville, is leading an effort to find bacteria to consume harmful algal toxins and clean up fresh water.

Wilhelm has been awarded $183,000 for the first year of an anticipated four-year, $704,000 project through NOAA's Prevention, Control, and Mitigation of Harmful Algal Blooms Program. He will collaborate with Gregory Boyer from the State University of New York College of Environmental Science and Forestry on the project.

Microcystin is known to be damaging to the liver and also potentially carcinogenic and tumorigenic. Its presence in water has grown over the years with the proliferation of the blue-green algae (cyanobacteria) that produces it. Blue-green algae thrive on nutrients found in fertilizers and sewage. The toxins pose a significant risk to some water supplies.

"One resource that isn't really renewable on the planet is water and we are putting more pressure on it as the population grows," said Wilhelm. "If results of climate change, population growth, changing land-use practices and so forth are these harmful algal toxins, water resources could be lost."

Wilhelm and his research team are working to clean up the toxins and restore water resources with a biofilter, containing a toxin-eating bacterium. The team will begin their research by isolating a number of bacteria which consume the toxin. They will decide which bacterium is the most feasible for the biofilter by determining consumption rates and considering the byproducts that exist after consumption. Then, the team will identify the physical infrastructure required for the biofilter.

"This biofilter could exist in a clean-up vessel, such as a portable buoy system in a lake. It could be dropped in an impacted area and water pumped through it," said Wilhelm. "The goal is reducing the likelihood of these toxins passing into water distribution systems."

Wilhelm's team will travel to China and throughout North America collecting water samples. He will also use samples sent to him from collaborators from around the globe.

Provided by University of Tennessee at Knoxville