Plastic-eating enzyme could eliminate billions of tons of landfill waste

Engineers and scientists at The University of Texas at Austin have created a variant of an enzyme that can break down environment-throttling plastic in a matter of hours.

One of the world's most pressing environmental problems is what to do with the billions of tons of plastic waste piling up in landfills and polluting our natural lands and water. Major industries would be able to reduce their environmental impact by recovering and reuse plastics at the molecular level if the enzyme were to be used.

Hal Alper, professor in the McKetta Department of Chemical Engineering at UT Austin, said that the possibilities are endless. We can begin to envision a true circular plastics economy through these more sustainable approaches.

Most consumer packaging, including cookie containers, soda bottles, fruit and salad packaging, and certain fibers and textiles, is made from the material polyethylene terephthalate. It makes up 12% of global waste.

The process of breaking down the plastic into smaller parts was completed by the enzyme. In some cases, the plastics can be fully broken down in a day or two.

A machine learning model was used by researchers at the Cockrell School of Engineering and College of Natural Sciences to create novel changes to a naturalidase that allowsbacteria to degrade plastic. The model predicts which changes in the enzymes will depolymerize plastic at low temperatures.

The researchers proved the effectiveness of the enzyme, which they are calling FAST-PETase, through studying 51 different post-consumer plastic containers, five different polyester fibers and fabrics and water bottles all made from PET.

The work demonstrates the power of bringing together different disciplines, from synthetic biology to chemical engineering to artificial intelligence, according to Andrew Ellington, professor in the Center for Systems and Synthetic Biology.

The most obvious way to cut down on plastic waste is to recycle. Less than 10% of plastic has been recycled. Burning plastic is the most common method for disposing of plastic, which is costly, energy intensive and emits noxious gasses into the air. Other alternative industrial processes are very energy intensive.

The solutions take less energy. Over the past 15 years, research has improved on the topic of plastic recycling. Until now, no one had been able to figure out how to make enzymes that were portable and affordable at large industrial scale. The process can be performed at less than 50 degrees.

Next, the team will work on scaling up production to prepare for industrial and environmental applications. The researchers are looking at several different uses for the technology. Greening industries and cleaning up landfills are the most obvious ways to reduce waste. Environmental remediation is one of the key potential uses. The team is looking at a number of ways to get the enzymes out into the field.

When considering environmental clean up applications, you need an enzyme that can work in the environment at ambient temperature. This requirement is where our tech has a huge advantage in the future.

The research was led by Alper, Ellington, and Nathaniel Lynd. The machine learning model was created by Danny Diaz. The other team members are from chemical engineering, as well as from molecular biosciences.

More information: Hal Alper, Machine learning-aided engineering of hydrolases for PET depolymerization, Nature (2022). DOI: 10.1038/s41586-022-04599-z. www.nature.com/articles/s41586-022-04599-z Journal information: Nature Citation: Plastic-eating enzyme could eliminate billions of tons of landfill waste (2022, April 27) retrieved 27 April 2022 from https://phys.org/news/2022-04-plastic-eating-enzyme-billions-tons-landfill.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.