The Improved PETase Enzyme: Hope for Cleaning the Oceans - Elizabeth Enriquez

If you take a look at the news nowadays, most of the headlines orbit around COVID-19 - deaths, confirmed cases, reopening of the economy, et cetera. The global pandemic is undoubtedly relevant, however, it is not the only event taking place. For example, scientists have recently created a newer, more effective enzyme for safely and quickly dissolving plastic.

Polyethylene terephthalate, or PET plastic, is a strong, rigid synthetic fiber and resin and a member of the polyester family of polymers. Since its creation in the 1940s, PET accounts for more than half of all synthetic fibers produced today. It is BPA-free, does not contain phthalates, and similar durability to glass, making it the perfect packaging material for food. Moreover, PET is 100% recyclable. Every year, more than 1.5 billion pounds of PET bottles and containers are recycled in the US. It almost seems too good to be true.

Keyword: almost.

While PET plastic may be recyclable, it is not biodegradable. It takes hundreds of years for it to break down in the environment. This plastic has been collecting in the oceans, forming garbage patches; the Great Pacific Garbage patch being of the most notable. Garbage and recycling floating in the ocean are harmful to the ocean ecosystem. As plastic starts to break down, it forms smaller particles of microplastic. In 2014, an estimated 15 to 51 trillion microplastic particles were floating in the oceans - amounting to between 93,000 and 236 tonnes of particles animals may try to eat.

In 2016, the enzyme PETase was first discovered. A team of scientists co-led by Professor John McGeehan, Director of the Centre for Enzyme Innovation (CEI) at the University of Portsmouth, and Dr. Gregg Beckham, Senior Research Fellow at the National Renewable Energy Laboratory (NREL) in the US, engineered the natural enzyme in a lab to be about 20 percent faster at breaking down the plastic. While this was an improvement, it was not enough that it could be used widely to effectively clean the plastic from the oceans.

However, as of recent, the same team of scientists combined the modified PETase and its counterpart, MHETase. PETase works at the surface of the plastic, while MHETase reduces the plastic even further. Combining the two into a 'super enzyme' increased the enzyme's ability threefold. This enzyme can shorten the breakdown time from hundreds of years to mere days.

The new combined MHETase-PETase digests the PET plastic and reconverts it to its original building blocks, which allows these plastics to be endlessly reused or harmlessly left alone. Not only will this help remove PET from the environent, but also reduce our reliance on fossil fuels and oils to produce more plastic. This MHETase-PETase enzyme may very well be the future of recycling, and a beacon of hope for the oceanic ecosystem. 

Although COVID-19 is important, it is sometimes difficult to remember that it is not the only thing going on in the world. The virus may have called the globe to come to a halt, but despite that, science is still moving forward. Even though the coronavirus has caused life as it is to flip on its head, that does not mean that we cannot continue to improve the world for the generations of the future.

https://www.sciencedaily.com/releases/2020/09/200928152913.htm

http://www.petresin.org/news_introtoPET.asp

https://www.worldanimalprotection.us/news/how-plastic-pollution-affecting-seals-and-other-marine-life#:~:text=Plastic%20contains%20toxic%20chemicals%2C%20which,even%20years%20before%20they%20die.&text=Nets%20and%20other%20man%2Dmade,seals%20and%20other%20sea%20animals.

https://en.wikipedia.org/wiki/PETase#:~:text=The%20first%20PETase%20was%20discovered,lipases%2C%20esterases%2C%20and%20cutinases.