Scientists have created a mutant enzyme that is able to break down plastic bottles for recycling in a matter of hours.
The new enzyme reduces polyethylene terephthalate (PET) – the plastic used to make most plastic drinks bottles – into chemical building blocks that can then be used to create high-quality new recycled bottles.
Independent experts have hailed the breakthrough, revealed in the scientific journal Nature, as a major advance for the recycling industry.
The novel enzyme, one of 100,000 micro-organisms screened by French company Carbios and their academic partner, the Toulouse Biotechnology Institute, was originally found in a compost heap of leaves.
“It had been completely forgotten, but it turned out to be the best,” said Professor Alain Marty, Carbios’ chief scientific officer and co-author of the report.
The team of researchers analysed the enzyme and introduced mutations to improve its ability to break down PET.
Using the optimised enzyme, the scientists were able to break down a tonne of waste plastic bottles, achieving a minimum 90% degradation within 10 hours, before using the material to create new food-grade plastic bottles.
Plastic pollution is one of the biggest ecological crises facing humankind today. An estimated eight million tonnes of plastic waste is dumped annually into the world’s oceans.
PET is one of the world’s most common plastics. It is used to manufacture bottles, polyester clothing fibres, food containers and other thermoformed packaging. However, current technology means recycled plastic bottles can usually only produce plastic of a lower quality.
Carbios is aiming to use the new enzyme for industrial-scale recycling within five years, partnering with Pepsi and L’Oréal to accelerate development.
Dr Saleh Jabarin, a professor at the University of Toledo in Ohio, USA, and a member of Carbios’ scientific committee, said: “It’s a real breakthrough in the recycling and manufacturing of PET. Thanks to the innovative technology developed by Carbios, the PET industry will become truly circular, which is the goal for all players in this industry, especially brand-owners, PET producers and our civilisation as a whole.”
