'Plastic-eating' enzymes to help combat textile waste

Approximately 60% of clothes worn today are made of synthetic textiles and they are often sent to landfill or incinerated at end of life.

Now, researchers at the University of Portsmouth’s Centre for Enzyme Innovation are using their enzyme technology (which has previously been used to recycle single-use plastics, including PET) to help combat polyester textiles in clothing waste.

Synthetic fabrics such as polyester are widely used for clothing due to their durability so the process of recycling them using enzymes will not be an easy one. The addition of dyes and other chemical treatments makes it even harder for these tough oil-based materials to be ‘digested’ in a natural process. Developing enzymes that can efficiently ‘eat’ polyester clothing, without energy-intensive pre-treatment, is the biggest challenge.

Professor Andy Pickford, Director of the Centre for Enzyme Innovation at the University of Portsmouth, said: “We will develop enzymes that can deconstruct the PET in waste textiles, tolerating the challenges that this feedstock poses, namely its toughness and the presence of dyes and additives.

“We will test the compatibility of our engineered enzymes with additives, dyes and solvents to select those enzymes that are best suited to polyester textile deconstruction. Then we will apply these enzymes to appropriately pretreated waste polyester textiles in laboratory-scale bioreactors to evaluate the potential and limitations of scaling up the technology.”

While it is possible to turn quality oil-based textiles into carpets and other products, current recycling methods are energy-intensive. Scientists hope that enzymes developed at the University of Portsmouth will help them create an environmentally friendly circular economy for plastic-based clothing.

Pickford said: “Our research will establish the feasibility of using enzymes to deconstruct the PET in waste textiles into a soup of simple building blocks for conversion back into new polyesters, thus reducing the need to produce virgin PET from fossil fuel-based chemicals. This will enable a circular polyester textiles economy and ultimately reduce our dependence on taking oil and gas out of the ground.

“We want a system that uses plastic in the same way we use glass or tin cans — infinitely recycled. The ultimate aim is to close the loop — however, this requires not only the technology but also the will to do so.”

The research, which is funded by the Biotechnology and Biological Sciences Research Council (BBSRC), started in January and is expected to last for 18 months.  The university team will work with project partners Biomimicry Institute, who will provide expertise in natural solutions to sustainability challenges, and Endura Sports clothing, who will share their knowledge of fabric dyes and provide samples of end-of-life polyester textiles.

Image credit: iStock.com/Annaspoka