Researchers use artificial intelligence to create an enzyme that breaks down PET to become new products
The sum of biology and technology equals an innovative solution to reduce the environmental impact of plastic disposal. Researchers at the University of Texas, in Austin (United States), have developed an enzyme capable of completely decomposing PET plastic waste — in some cases, in less than 24 hours; in others within a week, with natural degradation taking centuries to occur.
According to the study, this type of plastic represents 12% of solid waste generated worldwide, hence the importance of thinking about alternatives to degrade or reuse this material. When applied in large volumes, the enzyme can be used to clean landfills and plants of plastic waste, or simply places that have been polluted by this material.
The innovation proposed by this team, in a study published in the journal Nature, is to use artificial intelligence to design the hydrolase enzyme to break down PET into component molecules, which can then be transformed into new products.
Using hydrolase in PET was difficult because the enzyme was not robust enough in certain temperature and pH ranges and could not be applied directly to post-consumer plastics. Therefore, researchers developed a model of machine learning to generate new mutations in the PETase enzyme, which allows bacteria to degrade PET at low temperatures.
This new enzyme, called FAST PETase, was able to completely break down plastic samples from 51 different types of packaging that the team of researchers used to successfully generate new PET parts, both in mixed-color plastics and in transparent products.
“We demonstrated that untreated post-consumer PET from 51 different thermoformed products can be almost completely degraded by FAST-PETase within 1 week,” the study points out. “Collectively, our results demonstrate a viable route to industrial-scale enzymatic plastic recycling.”
“When considering environmental cleaning applications, we need an enzyme that can function in the environment at room temperature. This requirement is where our technology has a huge advantage in the future,” told the university's website Hal Alper, a lead researcher and professor in the McKetta Department of Chemical Engineering at the University of Texas at Austin.
With this solution, researchers want to make the circular economy of plastics a reality, that is, a model in which materials do not go to waste or landfill after use, but are instead reused as raw materials for new products.
“The possibilities are endless across all sectors to leverage this cutting-edge recycling process,” says Alper. “It also gives companies across all sectors the opportunity to lead the way in recycling their products. Through these more sustainable enzymatic approaches, we can begin to envision a true circular plastics economy.”
