Researchers in Germany have discovered a strain of bacteria capable of breaking down some forms of plastic. The finding could provide a much-needed recycling solution for toxic materials.
Polyurethane (PU) is a kind of plastic used for items like sports shoes, mechanical parts and synthetic fibres, like Spandex. It is hard to recycle because it is thermosetting, meaning it does not melt when heated up. Where other plastic can be processed and turned into new items, a lot of PU waste ends up in landfill. Once there, it releases toxic chemicals including carcinogens, the chemicals that can lead to cancer.
A team of scientists have now found a bacterium which attacks chemical bonds that keep the material together. Dr Hermann J. Heipieper, lead scientist at the Helmholtz Centre for Environmental Research UFZ explains how it all works; the bacteria take the building blocks for PU and use them as a source of energy. The plastic-eating microorganism was first found to have evolved at a waste site where PU was being dumped.
This is not the first example of nature adapting in response to our unsustainable addiction to plastic. In 2018, a different team of scientists discovered an enzyme capable of breaking down PET, the material used to make plastic bottles. This accidental breakthrough was made when looking at organisms that had evolved at a waste dump in Japan. While trying to work out how the process had occurred, they inadvertently changed something that made the molecule even better at breaking down the bottles.
Could this solve the problem of plastic pollution?
Despite these breakthroughs, it is important to ensure that advances of this kind don’t encourage an increase in plastic use - as most forms are still notoriously difficult to destroy. Already, Europe produces 60 million tonnes of plastic every year, but worryingly only around 30 per cent of this is eventually recycled.
Dr Heipieper tells Euronews Living that although these kinds of advances could lead to a more sustainable future, they aren’t the silver bullet for our plastic problem. “The problem of billions of tons of plastic waste, that are already in landfills or even in the ocean, will surely not be solved by bioremediation. Thus, it is now important to assess which plastic compounds are biodegradable.”
“It is conceivable that the industry will use more degradable precursors in the production of plastics in the future, taking into consideration scientific knowledge of the degradability by microorganisms,” added Dr Heipieper.
“However, a fundamental switch to new plastic compounds in the future will only be achievable through changes in governance and legislation.”