ADVANCING PLASTIC RECYCLING WITH NEWLY DISCOVERED SHIRT-CHEWING ENZYME

BY ASHMEETA SUBRA  DECEMBER 6TH, 2023

A team of researchers and scientists in France have been tweaking an enzyme that can break down the bonds in plastics, opening up new possibilities in plastic recycling. 

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In 2010, researcher Sintawee Sulaiman from the University of Osaka discovered an enzyme called LCC (leaf-branch compost cutinase) in decaying leaves at a nearby park, which may now lead to the transformation of plastic waste into a renewable resource.  

The process began with immersing plastic packaging shards from headphones overnight in water with samples of LCC. The next morning, Sulaiman observed holes and other signs of degradation in the plastics, a first indication that something of scientific significance could be at play.  

The plastic in question was PET, a polymer commonly used in packaging and textiles. Enzymes typically struggle to break down plastics due to their strong molecular bonds, but Sulaiman’s discovery indicated the possibility of enzymatic breakdown.   

Following Sulaiman’s early research, Professor Alain Marty and a team of researchers at the University of Toulouse in France spent over eight years re-engineering LCCinto another enzyme that is highly efficient at breaking down PET. This enzyme (LCCICCG) can break down PET polymer into its constituent monomers – chemicals needed to produce new plastic”We are using an enzyme that you can consider a molecular scissors,” Professor Marty told BBC news.

“We break down the link between the pearls, liberate the pearls and in this way, after purification, we can sell these pearls again.” 

A company founded by Professor Marty himself, Carbios, implemented this revolutionary enzyme at a demonstration plant in Clermont-Ferrand, France. Resembling a microbrewery, this plant features a large cylindrical reactor that is surrounded by equipment designed to process PET plastics.   

One of the company’s primary focuses is recycling polyester-rich clothing, which make up a significant portion of global clothing fibre production. The process involves shredding textiles, removing any embellishments, and transforming the remains into soft pellets.  

Carbios plans to scale up operations by opening a factory in northeast France by 2025 to recycle 50,000 tonnes of PET waste on an annual basis – around 300 million T-shirts or two billion bottles. There are also plans to license their innovation process to other entities, forming a consortium with big brands such as Nestle, L’Oréal and PepsiCo.   

Ms Sulaiman expressed satisfaction with the progress her initial discovery has achieved in breaking down the headphone packaging using LCC in 2010.  

“I feel very lucky to have met LCC,” she says.  

 “And I really hope that it can help the world – to change the world into a better place.” 

Within Australia, enzymatic recycling of plastics is also gaining pace. Samsara Eco have developed an enzymatic technology that breaks down plastics into their individual building blocks, known as monomers, which can then be used to make new products.  

The technology makes it possible to infinitely recycle plastics into new high-grade products rather than ‘downcycling’ them, allowing lower-impact alternatives to important materials in the apparel and packaging industries. Samsara Eco’s 2030 ambition is to recycle over 1.5M tonnes of plastic and textile waste per annum, saving an estimated 2.5M tonnes of CO2 emissions. 

Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.