What if cows could decompose plastic?

For years we have seen cows being “accused” of contributing to the depletion of the ozone layer through the methane they release during their digestive process.

Now, this same system seems to be able to provide clues for solving the plastic waste problem.

A team of researchers in Austria has published a study that indicates that microorganisms in the stomach of ruminants are able to break down various types of plastic.

The research began when researchers identified cutin molecules, a natural polyester produced by plants to protect plant cell walls, in the diet of cattle. This raised the suspicion that the stomach of these animals possess some structure/molecules capable of degrading this material. It was proven that the liquid produced in the rumen, the first of the four cavities of the cow’s stomach, produces an enzyme capable of also decomposing synthetic polyesters – PET (synthetic polymer commonly used in fabrics and packaging); PBAT (biodegradable plastic often used in compostable plastic bags); and PEF (bio-based material made from renewable resources).

Data showed that the three plastics could be decomposed by microorganisms present in the cows’ stomachs, in a laboratory environment, with polyesters in powder form being dissolved more quickly than those in film format.

It is not exactly a novelty that there are natural processes that act on plastic in a similar way, as in the case of bacteria that are able to metabolize polyurethane. However, after identifying the right enzymes (the next steps in the study aim to identify the microorganisms crucial for plastic degradation among the thousands present in the rumen and, then, the enzymes responsible for such task), researchers will be able to reproduce part of the large-scale digestive process of cows and replicate it in recycling plants as a more ecological and cheaper way of converting plastic waste.