The world faces a great plastic pollution crisis. The recent discovery of a plastic-eating enzyme at UT Austin could be a game-changer to address this.
Research suggests that the world is generating twice as much plastic as two decades ago, with the majority being incinerated or ending up in landfills or dispersed in the environment, particularly in oceans.
According to Global Plastics Outlook Report published by the Organization for Economic Co-operation and Development (OECD), only 9% of plastic is successfully recycled while 22% of plastic is mismanaged.
Because plastic is not naturally biodegradable, teams of researchers and scientists are always devoting time and resources to finding new, innovative ways to solve the growing problem of global plastic pollution.
Researchers at the University of Texas (UT) at Austin have used a new machine learning (ML) algorithm to create a new variant of enzymes that can degrade plastic.
Understanding the global plastic waste crisis
The United Nations Environment Program (UNEP) estimates that about 7 billion tons of plastic produced between 1950 and 2017 became plastic waste that was thrown away or ended up in landfills. Plastic waste can negatively impact the environment and its natural processes, contribute to climate change and affect the livelihoods of millions of people and global food production capacities. Chlorinated plastic can spread harmful chemicals if not properly disposed of or degraded, they harm the soil, groundwater and surrounding ecosystems.
Increasing amounts of plastic pollution can also impact human health and well-being. Researchers believe that children are exposed to microplastics and their smaller counterparts – called nanoplastics – more often than adults. The latter can also face adverse health effects from microplastics, including DNA damage and inflammation. If the inflammation becomes chronic, adults may need medical intervention to receive appropriate care.
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It is well known that plastic can also damage the environment and vulnerable animal populations living in affected areas. With the increasing amount of plastic polluting natural lands and waterways around the world, it is crucial to adopt new technologies and develop alternative packaging to address the root causes of pollution.
Researchers develop new plastic-eating enzyme
Hal Alper is a Principal Investigator of the Technical Biology Team in the McKetta Department of Chemical Engineering at UT Austin. He is also a professor and a Les and Sherri Stuewer Professor of Chemical Engineering at UT.
Alper and his team of engineers and scientists created a variant of an enzyme called hydrolase using an ML algorithm. The enzyme is able to break down PET (polyethylene terephthalate), one of the most commonly used plastics today, into its constituent molecules.
PET polymer is most commonly found in consumer packaged products, such as soft drink, salad and fruit containers, as well as disposable food trays. According to a National Library of Medicine review, in 2021, PET packaging represented:
- 12% of global solid waste
- 44.7% of single-serve beverage packaging in the United States
However, once PET plastic waste breaks down, it can be reused to create entirely new PET materials, essentially leading to a circular plastics economy. In the past, attempts at enzymatic degradation have failed, primarily due to a lack of robustness to acidity (pH), temperature ranges, and slow reaction rates.
During the project, Alper and the UT Austin team discovered that the new plastic-eating enzyme, called FAST-PETase (Functional, Active, Stable, and Tolerant PETase), can break down plastics. at a much faster pace than other PET hydrolases used in previous studies. It is also capable of degrading mixed color and transparent PET plastic products.
Unprocessed post-consumer PET from 51 different products was almost completely degraded by the new enzyme FAST-PETase in just one week. At 50°C, the team reported that portions of a whole heat-pretreated water bottle and a commercial water bottle could also be broken down.
The potential benefits of the plastic-eating enzyme
Because this new enzyme can break down plastics so quickly and on a large scale, it will have virtually unlimited potential to help many industries in their waste reduction efforts.
For many environmental cleaning activities, controlling the outside temperature is a major challenge. The plastic-eating enzyme is sensitive to temperature changes, which renders enzymatic degradation ineffective.
Since the FAST-PETase enzyme degrades plastic and simultaneously manages temperature variations, it would be effective in non-laboratory conditions. This new discovery could be a major benefit for environmental organizations and other agencies focused on cleaning up the environment.
With sufficient amounts, the enzyme can clean up landfills, waste treatment plants and other sites negatively affected by plastic pollution. The plastic-eating enzyme is affordable, portable, and can be widely applied. The role of ML in this research is essential. Without the model developed by the UT researchers, the new enzyme discovery might not have been possible.
Harness the power of AI to solve environmental problems
The University of Texas team has filed a patent to explore the potential applications of this new technology. The goal is to scale up the manufacturing of the FAST-PETase enzyme so that it can be used practically in the environmental and industrial sectors. It will be interesting to see the potential impacts of this discovery and whether it will help solve the problem of plastic pollution.
Image featured by CDC on Unsplash
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