‘We are just getting started’: the plasticeating bacteria that could change the world

In 2001, a group of Japanese scientists made a startling discovery at a rubbish dump. In trenches packed with dirt and waste, they found a slimy film of bacteria that had been happily chewing through plastic bottles, toys and other bric-a-brac. As it broke down the trash, the bacteria harvested the carbon in the plastic for energy, which it used to grow, move and divide into even more plastic-hungry bacteria. Even if not in quite the hand-to-mouth-to-stomach way we normally understand it, the bacteria was eating the plastic.

The scientists were led by Kohei Oda, a professor at the Kyoto Institute of Technology. His team was looking for substances that could soften synthetic fabrics, such as polyester, which is made from the same kind of plastic used in most beverage bottles. Oda is a microbiologist, and he believes that whatever scientific problem one faces, microbes have probably already worked out a solution. “I say to people, watch this part of nature very carefully. It often has very good ideas,” Oda told me recently.

What Oda and his colleagues found in that rubbish dump had never been seen before. They had hoped to discover some micro-organism that had evolved a simple way to attack the surface of plastic. But this bacteria was doing much more than that – it appeared to be breaking down plastic fully and processing it into basic nutrients. From our vantage point, hyperaware of the scale of plastic pollution, the potential of this discovery seems obvious. But back in 2001 – still three years before the term “microplastic” even came into use – it was “not considered a topic of great interest”, Oda said. The preliminary papers on the bacteria his team put together were never published.

In the years since the group’s discovery, plastic pollution has become impossible to ignore. Within that roughly 20-year span, we have generated 2.5bn tonnes of plastic waste and each year we produce about 380 million tonnes more, with that amount projected to triple again by 2060. A patch of plastic rubbish seven times the size of Great Britain sits in the middle of the Pacific Ocean, and plastic waste chokes beaches and overspills landfills across the world. At the miniature scale, microplastic and nanoplastic particles have been found in fruits and vegetables, having passed into them through the plants’ roots. And they have been found lodged in nearly every human organ – they can even pass from mother to child through breast milk.

Current methods of breaking down or recycling plastics are woefully inadequate. The vast majority of plastic recy