Repurposed beer yeast can extract lead, other metals from water: Study

The researchers estimate that one year’s worth of discarded yeast from just one brewery could filter all the water in a city the size of Boston.

by Rich Johnson | May. 20, 2024

Story at a glance

Researchers at MIT and Georgia Tech have produced a filter from used brewer’s yeast that can absorb lead and other heavy metals from water.

The new filter works through biosorption, in which lead binds to the yeast.

The filter that resulted from the research was able to treat lead-contaminated water to meet EPA drinking water standards while operating continuously for 12 days.

(NewsNation) — They’re still not sure how it works, but researchers at MIT and Georgia Tech have produced a filter from used brewer’s yeast that can absorb the tiniest amounts of lead and other heavy metals from water.

Through a process called biosorption, the yeast can bind to lead, as well as the metals commonly used in electronic components. That, say the researchers, could be a game-changer when recycling those metals.

PORTLAND, MAINE – MARCH 10: Patrick Damon removes yeast from beer during the brewing process at D.L. Geary’s Brewery in Portland Friday, March 10, 2017. The brewery was recently sold to Alan Lapoint of Freeport. (Staff Photo by Gabe Souza/Portland Portland Press Herald via Getty Images)

But the more valuable impact may be the ability to filter drinking water, starting with home faucets, and eventually scaling up to serve municipal water systems.

Research published in 2021 said that, through biosorption, a process that is not fully understood, yeast cells can bind to and absorb heavy metal ions. However, the unsolved problem was how to get the yeast out of the water once it had absorbed the lead.

The solution came thanks to a scientific conference in Boston where the yeast researchers were introduced to a student looking at ways to capture micropollutants in water.

The two teams devised a way to put the yeast into tiny porous capsules similar to vitamin pills. That way, the yeast could bind to the lead in the water, but not escape into the water.

The filter that resulted from the research was able to treat lead-contaminated water to meet EPA drinking water standards while operating continuously for 12 days.

The researchers are now exploring ways to recycle and replace the yeast inside the half-millimeter-long capsules, and how often they need to be replaced.

One thing that is not a problem: finding yeast. Brewers discard tons of surplus yeast. The researchers estimate that one year’s worth of discarded yeast from just one brewery could filter all the water in a city the size of Boston.