“A newly discovered ‘super-enzyme’ could finally mean effective recycling of plastic bottles and other materials, scientists say. The plastic-eating bacteria can digest plastic six times faster than current methods of chemically breaking it down.
Scientists first discovered one enzyme several years ago, and the new “cocktail” replaces a previous version that had less plastic-eating complexity and robustness. In a new paper, a large team that spans the Atlantic delivers its findings as well as its recommendations for how to introduce the enzyme into the plastics supply chain. By combining two enzymes on purpose, laboratory scientists break polyethylene terephthalate (PET) into ‘intermediate’ parts, and then into elementary parts.
The bacterial product PETase enzyme turns PET into its “constituent monomers,” or building blocks. Now that scientists know about the two-step enzyme system, they wonder if bacteria that have evolved some plastic-digesting mechanisms already will continue that way and grow mechanisms that will further digest plastic—in line with the two-step system scientists understand.
For now, they’ve mixed enzymes from two different kinds of bacteria into one system that breaks plastic down in phases that are much faster. “Our first experiments showed that they did indeed work better together, so we decided to try to physically link them, like two Pac-men joined by a piece of string,” University of Portsmouth professor and study leader John McGeehan said in a statement.
The enzymes work together to ‘chop’ the most common consumer plastic into chemical building blocks, which means they can be reapplied as the ingredients for the next generation of plastics instead of distilling these ingredients from newly extracted petrochemicals. McGeehan is also director of the University of Portsmouth’s Centre for Enzyme Innovation, where scientists identify naturally occurring enzymes, study their chemical makeup, and find ways to synthesize them in the laboratory.”
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