CAN PLASTIC EATING ENZYMES SOLVE RECYCLING ?
The invention of the first man-made plastic, celluloid, in the nineteenth century was hailed as revolutionary. With the discovery came a seemingly infinite conveyor-belt of products, newly affordable to the average consumer. No industry was left untouched by this cheap, malleable, bountiful resource.
Today — as plastic clogs our oceans, flows from landfills and sends plumes of smoke into the atmosphere in the rush to burn it — attitudes are a little different.
Since the first factories started pumping out polyester in the 1950s, an estimated 8.3bn tonnes of plastic has been produced1. But, of each year’s 360mn tonnes of plastic waste2, less than 10 per cent is recycled3. The rest ends up in landfills, waste incinerators or nature. Microplastics have been found in penguins, breast milk, bottled water, human blood, and on the summit of Mount Everest. Most plastic will never decompose.
Even recycled plastic is eventually destined for the dump. Conventional, mechanical recycling — where plastic is ground into flakes, melted, and moulded anew — yields plastic more brittle and less durable than its originator. It is often difficult to use the material more than three times.
Scientists have spent decades grappling with this plastic predicament. In recent years, an unlikely ally has emerged: plastic-munching microorganisms.
Carbios, a French biotechnology start-up, is among the innovators looking to commercialise depolymerisation — or enzymatic — recycling. This uses genetically-modified microorganisms to break down the polymer chains that make up plastic, leaving only its initial building-blocks, or monomers. The monomers can then be put back together into plastic that’s as good as new. In theory, a bottle made this way could be recycled indefinitely.
