AI designs an enzyme that ‘eats’ plastic in days

The world works to end the consumption of plastic. There are already several companies that have eliminated this compound from their production chains. But there’s still a lot to do. Just in a year eight million tons of plastic end up in the sea. This problem greatly affects nature. Where more than 270 species have become entangled and more than 240 have ingested plastics, according to the World Wide Fund for Nature (WWF).

This situation not only affects the environment. It also poses a risk to people. A study shows that a person could ingest 5 grams, approximately, of plastic per week. If we want to avoid our consumption of small plastic parts, there is still a long way to go. Plastic is a ubiquitous material, easy and cheap to produce that, moreover, does not degrade easily.

The reason? Plastic is made up of complex polymers, that is, long, repeating chains of molecules that do not dissolve in water. The resistance of these chains causes the plastic to be a compound that takes a long time to break down naturally. If we add to this the amount of plastic we consume, we find ourselves facing a serious problem. It is estimated that, until these polymers begin to disintegrate at the molecular level, it can take at least 450 years.

For several years there have been various investigations that have been developed around the elimination of plastic. Now, engineers and scientists at the University of Texas at Austin have created an enzyme that can break down plastic waste in hours or days. Without a doubt, this is a very important advance, since, as we mentioned before, nature takes hundreds of years to degrade this compound.

Artificial Intelligence, an ally in the fight to put an end to plastic

The research focuses on the polyethylene terephthalate (PET), an essential polymer that we can find in the vast majority of consumer plastic containers. From containers of bottles of soft drinks, salads and fruits, cookies, even in certain fibers and textiles. PET makes up 12% of all global waste.

These researchers ran a model of machine learning to develop a series of mutations in a natural enzyme, PETase, which allows bacteria to degrade PET plastics. Therefore, this model predicts which mutations in these enzymes could depolymerize post consumer waste plastic at low temperatures and rapidly.

The enzyme, named FASY PETAse, has shown that it is possible to break down this plastic into smaller parts (depolymerization). And, later, chemically join it again (repolymerization). Based on this, in some cases, these plastics can be completely broken down into monomers in as little as 24 hours.

In addition, the team of scientists has already tested this initiative in a study of 51 plastic containers different post consumer, five polyester fibers and fabrics and water bottles made of PET, proving their effectiveness with the complete decomposition of the matter in 48 hours, and in some cases in a day.

Towards a future without PET waste

Until now, enzyme based methods required high temperatures. However, this new one can carry out the process at less than 50 degrees centigrade, being greener, faster and cheaper. In the next phase, these researchers are working to expand the production of this enzyme and prepare its environmental and industrial application.

The scientific team has filed a patent application for this technology. Among its future applications is the cleaning of landfills and those industries that produce a lot of waste. In addition to its obvious applications in the environment. “When considering environmental cleaning applications, an enzyme that can function in the environment at room temperature is needed. This requirement is where our technology has a great advantage in the future.”, concludes Hal Alper, professor in the Department of Chemical Engineering at the University of Texas Austin.

Without a doubt, this is an essential way to promote recycling on a large scale, allowing industries to reduce their environmental impact, thanks to the recovery and reuse of plastics at the molecular level.