Plastic is known to be difficult to break down, but researchers in Austria have found that bacteria from a cow’s rumen – one of the four compartments of its stomach – can digest certain types of the ubiquitous material, which is a sustainable way to reduce plastic waste.
Scientists suspected that such bacteria could be useful because cow feed already contains natural plant polyesters. “A huge microbial community lives in the rumen reticulum, which is responsible for the digestion of food in the animals,” says Dr. Doris Ribitsch from the University of Natural Resources and Life Sciences, Vienna, “therefore we suspected that some biological activities might also be possible” are used for polyester hydrolysis “, a kind of chemical reaction that leads to decomposition. In other words, these microorganisms can already break down similar materials, so the study authors thought they could potentially break down plastics too.
Ribitsch and her colleagues looked at three types of polyesters. One, polyethylene terephthalate, commonly known as PET, is a synthetic polymer commonly used in textiles and packaging. The other two consisted of a biodegradable plastic that is often used in compostable plastic bags (polybutylene adipate terephthalate, PBAT) and a bio-based material (polyethylene furanoate, PEF) made from renewable raw materials.
They obtained rumen fluid from a slaughterhouse in Austria to obtain the microorganisms they were testing. Then they incubated that liquid with the three types of plastic they tested (which were tested in both powder and film form) to understand how effectively the plastic would break down.
According to their findings, recently published in Frontiers in Bioengineering and Biotechnology, all three plastics could be broken down by the microorganisms in cow stomachs, with the plastic powders breaking down more quickly than plastic sheeting. Compared to similar studies done to study individual microorganisms, Ribitsch and her colleagues found that the rumen fluid was more effective, which could suggest that their microbial community may have a synergistic advantage – that the combination of enzymes, not one specific enzyme that makes all the difference.
While her work has so far only been carried out on a laboratory scale, Ribitsch says: “Due to the large amount of rumen that accumulates in slaughterhouses every day, upscaling would be easy to imagine.” and such studies require preliminary studies to study microorganisms.
Still, Ribitsch looks forward to further research on the subject and says that microbial communities are under-explored as a potential environmentally friendly resource.