Scientists in the English coastal city of Portsmouth have discovered a potential solution to plastic pollution in the form of a new enzyme will that will ‘eat’ plastic bottles.

Researchers at the University of Portsmouth and the US Department of Energy’s National Renewable Energy Laboratory (NREL) discovered an enzyme that digests polyethylene terephthalate, or PET, which currently takes hundreds of years to break down.

Professor John McGeehan at the University of Portsmouth and Dr Gregg Beckham at NREL were examining a bacterium that had naturally evolved to eat plastic at a waste dump in Japan. An ultra-high-resolution 3D model of the PETase enzyme produced by the bug was generated, and during the study they inadvertently engineered an enzyme even better at degrading PET.

Professor McGeehan, Director of the Institute of Biological and Biomedical Sciences at Portsmouth, said: “Although the improvement is modest – 20% better – this unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics.”

About one million plastic bottles are sold each minute around the world, with just 14% recycled. Experts estimate that by 2050, there will be as much waste plastic in the ocean by mass as there are fish.

Significantly, the enzyme can also degrade polyethylene furandicarboxylate, or PEF, a bio-based substitute for PET plastics that is being hailed as a replacement for glass bottles.

McGeehan said: “The engineering process is much the same as for enzymes currently being used in bio-washing detergents and in the manufacture of biofuels – the technology exists and it’s well within the possibility that in the coming years we will see an industrially viable process to turn PET and potentially other substrates like PEF, PLA, and PBS, back into their original building blocks so that they can be sustainably recycled.”

Meanwhile, The University of Portsmouth’s Faculty of Creative and Cultural Industries is embarking on the research project ‘PlastiCity’, co-lead by Professor Steffen Lehmann,

School of Architecture Lecturer and Director of the Cluster for Sustainable Cities. He has teamed up with Professor Steven De Meester from the University of Ghent, in Belgium, to tackle research on plastic waste.

The innovative project has received funding by Interreg-2-Seas, a European Territorial Cooperation Programme covering areas of England, France, Belgium, and the Netherlands.

The overall objective of PlastiCity is to develop an innovative plastic recycling hub and method for affordable collection, sorting and treatment of plastic waste in the 2-Seas area. The Euro 6 million project will incorporate mapping the plastic waste flows in the region, before looking at business scenarios optimising collection, separation and reprocessing methods at a future ‘urban plastic refinery’.

Education towards behaviour change is another part of the strategy, including: reducing the amount and number of different plastics used at source; banning plastic products that are hard to recycle, and taxing single-use plastic items, such as cups, cutlery and straws.

 


(via University of Portsmouth, CNN, The Guardian, Research and Innovation Portsmouth)