Once they understood its structure, the team noted that they could improve the performance of PETase by adjusting a few residues on its surface.
The findings are reported in Proceedings of the National Academy of Sciences (link down at time of writing).
NREL and the University of Portsmouth collaborated closely with a multidisciplinary research team at the Diamond Light Source in the United Kingdom, a large synchrotron that uses intense beams of X-rays 10 billion times brighter than the sun to act as a microscope powerful enough to see individual atoms.
Polythylene terephthalate or PET is one of the worst man-made plastics for recycling taking hundreds of years to break down into the environment. The enzyme can also degrade polyethylene furandicarboxylate (PEF), a bio-based substitute for PET plastics that is being hailed as a replacement for glass beer bottles. These differences indicated that PETase must have evolved in a PET-containing environment to enable the enzyme to degrade PET. And the problem with the recycled plastic is that it can only be turned into fiber that is used in other applications; think carpeting, fleece and tote bags.
Though the rise of plastics since the 1960s has led to tons of trash floating around the world's oceans, the discovery brings hope that plastic bottles will soon stop their accumulation in our water.
Prof McGeehan, director of the Institute of Biological and Biomedical Sciences in the School of Biological Sciences at Portsmouth, said: "We can all play a significant part in dealing with the plastic problem, but the scientific community who ultimately created these "wonder-materials", must now use all the technology at their disposal to develop real solutions". The Portsmouth University team, and their collaborators, the US National Renewable Energy Laboratory in Colorado, have since filed for a patent. But instead of the mutated PETase proving more ineffective at degrading PET, the team found the opposite, that it actually performed better.