PET Hydrolase: A Series of Fortunate Events

Informative Article


Due to an incredibly fortunate accident, scientists have discovered PETase, an enzyme that can break down plastic. Well then, why is it controversial? It’s mutated.


by Aashna Chudgar

Due to an incredibly fortunate accident, scientists have discovered a new enzyme named PET Hydrolase, or PETase, that has the ability to break down PET plastics. The thing giving this enzyme a controversial rep? It’s mutated.


PET plastic is just a fancy name for polyester, a lightweight plastic that is commonly used in things like Ziploc bags, storage containers, and, nature’s worst enemy, the plastic water bottle. According to the Smithsonian Magazine, Japanese researchers discovered a strand of bacteria that could break down plastics after digging through waste piles. Later, scientists at the University of Portsmouth in the U.K. and the U.S. Department of Energy’s National Renewable Energy Laboratory accidentally manipulated the structure of the bacteria and turned it into a mutant enzyme. This enzyme has the ability to break down 90% of the plastic it is exposed to into safe, clean, and reusable plastic.


If this enzyme is able to work effectively, it could be a revolutionary breakthrough in environmental science. We could not only help degenerate all of the plastic filling up the ocean, but would also allow us to severely cut down on oil consumption and overall stop polluting our planet as much. So, what makes this enzyme controversial? Plastics have to be converted into PET plastics using biotechnology and a lot of fuel to alter them before they can be sent into markets, which could make it much harder to sustainably produce these plastics. Additionally, this enzyme is mutated, so scientists aren’t quite sure what side effects come with this bacteria.


So, this brings us to the Trilemma: should we go ahead with a project that could end nearly all plastic pollution on the planet, stop this project on account of economic issues, or remain at a neutral stance? Let’s find out.


The Environmental Perspective


A great benefit of using the enzyme is that we will be able to recycle much more plastic than before. According to Forbes, Americans recycle less than 10% of all plastics. The rest ends up in landfills, incinerators, or oceans. On top of that, even with our highest quality manufacturing of plastic, only 20-30% of all plastics can actually be recycled. With PETase, any plastic containing the enzyme can be 90% recycled into plastic that’s good as new. All of the plastic that goes to landfills could take up to a thousand years to decompose, not to mention could also release incredibly toxic chemicals that could result in many things, including cancer and reproductive issues. There’s about 100 million tons of plastic in the ocean right now. Using PETase to break down all of that plastic could lead to the un-endangerment of so many species, as well as being able to insert so much more cleaner plastic into our country instead of manufacturing more.


The main idea of this enzyme is to find a way to stop dumping all of our plastic waste into the environment. According to ScienceDaily, 50 million tonnes of PET plastic are produced every year. The number of plastics that are recycled while producing after-products like dirty oil makes up a small percentage of all recycled plastics, which argues that sustainability is possible to achieve. Additionally, the processes that recycle these plastics are incredibly energy consuming and expensive to maintain, on account of all of the compression factories use to recycle their products, so it could be argued that PET plastics could potentially be less expensive.


The Sustainable Perspective


The main reason anyone would have a grudge against these plastics is because of all of the different factors that may not be able to be sustained. PETase can only recycle PET (polymer) plastics, which require a lot of oil. According to Forbes, the manufacturing of plastic PET water bottles uses about 17 million barrels of oil every year. That’s roughly how much fuel it takes to power a million cars. With the current diminishing rate of fossil fuels on top of how much pollution oil-based production creates, trying to maintain this production system will eventually become downright impossible.


Additionally, enzymes need specific factors to be regulated in order for them to perform optimally, including keeping the temperature at 72 degrees constantly and crushing the substrate (plastic) to mix in the enzyme. PET plastics are extremely compressed sheets of plastic, and need to be fully demolished before the enzyme can recycle the used plastic. The amount of manpower and machinery it would require to completely destroy all plastics before inserting the enzyme would require a lot of maintenance and energy.


The Neutral Stance