A plastic-eating enzyme might dissolve billions of tons of landfill waste

A plastic-eating enzyme might dissolve billions of tons of landfill waste ...

Environmental-throttling plastics, developed by engineers and scientists at The University of Texas at Austin, can be degraded in a matter of hours to days.

This discovery, published today in Nature, might help resolve one of the world''s most pressing environmental issues: what to do with the billions of tons of plastic waste piling up in landfills and polluting our natural lands and water. The enzyme has the potential to supercharge recycling on a large scale, which would allow major industries to reduce their environmental impacts by recovering and reusing plastics at the molecular level.

The possibilities for a pioneering recycling technique are endless across industries, according to Hal Alper, a professor at UT Austin. Beyond the obvious waste management industry, this also provides corporations from every country the opportunity to take a lead in recycling their goods. Through these more sustainable enzyme approaches, we can begin to envision a true circular plastics economy.

Polyethylene terephthalate (PET), a significant polymer found in most consumer packaging, including cookie containers, soda bottles, fruit and salad packaging, and several fibers and textiles. It makes up 12% of all global waste.

In some instances, the enzyme was able to complete a circular process of depolymerization, then chemically putting the plastic back together (repolymerization). In some instances, these plastics may be completely broken down to monomers in less than 24 hours.

Researchers at the Cockrell School of Engineering and the College of Natural Sciences used a machine learning technique to produce novel mutations to a natural enzyme called PETase that allows bacteria to degrade PET plastics. The following model predicts which mutations in these enzymes would achieve the objective of quickly depolymerizing post-consumer waste plastic at low temperatures.

Researchers have demonstrated the effectiveness of the enzyme, which they call FAST-PETase (functional, active, stable, and tolerant PETase) through this process.

According to Andrew Ellington, a professor at the Center for Systems and Synthetic Biology, whose team led the development of the machine learning model, this work demonstrates the power of bringing together different disciplines, from synthetic biology to chemical engineering.

The most obvious method to reduce plastic waste is to dispose of it instead of throwing it in a landfill. It is costly, energy-intensive and takes out harmful chemicals into the air. Other alternative industrial methods include glycolysis, pyrolysis, and/or methanolysis.

Biological solutions require much less effort. Over the past 15 years, research on enzymes for plastic recycling has developed. However, no one had ever been able to determine how to make enzymes that could perform efficiently at low temperatures, allowing them to be both portable and affordable at large industrial scale. FAST-PETase can perform the process at less than 50 degrees Celsius.

The development team is planning to begin a scaling up enzyme production to prepare for an industrial and environmental application. The researchers have filed a patent application for the technology and are applying several technologies. Environmental remediation is the most obvious.

When it comes to environmental cleanup applications, you need a technique that can function in the environment at ambient temperature. This is where our technology has a significant advantage in the future, according to Alper.

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