(MOL) AS SIMPLE AS PETASE, TPADO, EG & TPA

While the importance of recycling is regularly hammered home to us, plastic waste around the world is at an all-time high, with a whopping 353 million tonnes produced every year.

Now, scientists believe they may have the solution to reducing plastic waste, in the form of enzymes that eat polyester.

The first enzyme, called PETase, was discovered back in 2016, but until now it's been largely unusable because it breaks down at high temperatures.

In a new study, researchers from Northwestern University designed a polymer that protects the enzyme, allowing it to break down polyester even at high temperatures.

Meanwhile, a second study, led by researchers from Montana State University and the University of Portsmouth, identified a second enzyme, called TPADO, that breaks down terephthalate (TPA) - one of the two chemicals produced when polyester breaks down.

Together, the researchers hope the enzymes could help engineers develop solutions for removing microplastics from rivers and oceans

'Our idea was to build polymers capable of encapsulating the enzyme to protect its structure, so that it can continue to function outside of living cells and in the lab at sufficiently high temperatures to be able to break down PET,' explained Professor Monica Olvera de la Cruz, senior author of the first study.

The polymer consists of a hydrophobic (water repelling) backbone, and highly specific concentrations of its three components.

To put it to the test, the team mixed the polymer with chemically synthesised PETase in the lab.

We found that if you put the complex of the polymer with the enzyme together, and close to a plastic, and then you heat it up slightly, the enzyme was able to break it down into small, monomeric units,' Professor Olvera de la Cruz said.

'In addition to operating in an environment like where it could clean microplastics, our method has protected against high temperature degradation, and one student was able to do the testing.'

When PETase does break down polyester, it leaves behind two chemicals - ethylene glycol (EG) and terephthalate (TPA).

In a separate study, researchers from Montana State University and the University of Portsmouth looked at the next steps for these chemicals.

Professor Jen DuBois, who led the study, said: 'While EG is a chemical with many uses – it's part of the antifreeze you put into your car, for example – TPA does not have many uses outside of PET, nor is it something that most bacteria can even digest.' Mail Online - link - Shivali Best - link - picture - link - more like this - link