National & World News

Microbes from the guts of cows can break down plastic

by Brooks Hays

Washington DC (UPI) Jul 2, 2021

Microbes found in a cow's stomach can breakdown plastics, according to new research.

Researchers found the polymer-munching microbes in the rumen, one of four compartments

comprising the bovine stomach. The bacteria, described Friday in the journal Frontiers in

Bioengineering and Biotechnology, could be used to reduce plastic litter in landfills and polluted ecosystems. The discovery wasn't entirely unexpected, as the diet of cows and other ruminants features a significant amount of natural plant polyesters.

Scientists figured the bacteria could probably break down synthetic plastics, too, which

are similar in their construction and chemical composition.

"A huge microbial community lives in the rumen reticulum and is responsible for the

digestion of food in the animals," study co-author Doris Ribitsch said in a press release.

"So we suspected that some biological activities could also be used for polyester

hydrolysis," said Ribitsch, a researcher at the University of Natural Resources and Life

Sciences in Vienna, Austria.

In the lab, researchers exposed three different types of plastics to the cow rumen-

derived microbes.

First, scientists fed the bacteria polyethylene terephthalate, or PET, a synthetic polymer

used in textiles and packaging.

Researchers also tested polybutylene adipate terephthalate, PBAT, a biodegradable

plastic used to make plastic bags, and and bio-based polymer material called

polyethylene furanoate.

The microbes living in the rumen liquid successfully broke down all three plastics much

more efficiently than previously tested bacteria strains, suggesting a synergistic

advantage among the community of microbes living in a cow's stomach.

These microbes likely produce not one, but a multitude of enzymes capable of breaking

down plastic.

"Due to the large amount of rumen that accumulates every day in slaughterhouses,

upscaling would be easy to imagine," Ribitsch said.

Ribitsch and her colleagues plan to continue testing the plastic-eating abilities of

microbial communities.

"Despite the fact that rumen fluid could be a cheap source for polymer-degrading

enzymes, future studies should aim at identification and cultivation of the microbes and

enzymes," researchers wrote.