Cowing Plastics?

Herbivores (like cows) need help from 'friendly' stomach bacteria to breakdown the cellulose walls of their exclusively plant-based diet. Cellulose is a polymer, as are plastics. It was, consequently, logical for Doris Ribitsch and her colleagues (University of Natural Resources and Life Sciences, Vienna) to explore the ability of the fluid in a cow's rumen (a stomach compartment), to break down plastics (https://www.theguardian.com/environment/2021/jul/02/study-suggests-bacteria-in-cows-stomach-can-break-down-plastic). Ribitsch and her colleagues obtained gallons of rumen fluid from slaughterhouses. The fluid was incubated with PET (a synthetic polymer used in textiles and packaging); PBAT (a material used to make compostible plastic bags) and PEF (a biobased material used to manufacture renewables). The plastics were added to the vats in both film and powder form. All three polyesters were broken down by bacterial enzymes. Powders (because of their greater surface areas?) were broken down faster. The race is now on to determine which bacteria is/are producing the effective enzyme or (more likely) enzymes. Other bacteria, from other locations, have already been shown to have the potential to facilitate environmentally-effective ways of disposing of the burgeoning plastic waste. It would be best to use purified enzymes in designed industrial plants, as cows have nasty habit of burping out methane. Methane is a very potent 'greenhouse gas'. It would also be a good idea to use less plastic.