A huge step forward! Mutant enzyme could vastly improve recycling of plastic bottles
Recycling isn't as guilt-free as it seems. Only about 30% of the plastic that goes into soda bottles gets turned into new plastic, and it often ends up as a lower strength version. Now, researchers report they've engineered an enzyme that can convert 90% of that same plastic back to its pristine starting materials.
That enzyme, known as leaf-branch compost cutinase (LLC), snips the bonds between PET's two building blocks: terephthalate and ethylene glycol. But LLC, which evolved to break down the waxy protective coating on many plants’ leaves, slowly breaks apart PET bonds only, and falls apart after just a few days of working at 65°C, the temperature at which PET begins to soften, which allows the enzyme to more easily wiggle into the polymer to reach the links it seeks to break.
Work is underway to scale up the technology and open a demonstration plant next year.
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