Plastic that eats itself? Not a rubbish idea

Scientists may have come up with a novel solution to the world’s litter crisis: a plastic that eats itself.

The material is soft and flexible and has been designed to be used for things such as watch straps or the soles of trainers.

However, it contains an unusual extra ingredient: dormant bacteria that will wake up and consume it once the plastic is discarded and buried.

The microbes are incorporated as spores that can lie dormant for years. In trials, they revived when the plastic was covered with a sterile compost. They then degraded it in about five months.

The volume of plastic waste being created each year is estimated to have more than doubled globally since 2000, with almost a quarter being dumped, burnt in open pits or leaked into the environment.

The new self-eating plastic is a type of polyurethane, according to Jon Pokorski, a professor at the University of California San Diego, who led the research.

“Dormant bacteria are integrated in the plastic. When they are exposed to nutrient sources, like water and sugar, they begin to replicate. As they grow and divide, they break down the plastic,” he said.

It was unlikely that the bacteria would wake up early and begin eating the plastic while it was still in use. “These types of polymers wouldn’t see any sufficient nutrient source in their usual applications.”

His team had been surprised to find adding the microbe spores to the material made it stronger. “The cool part about this is that it improves the material properties

... but at the end of life, regardless of where the plastic is disposed of, it will break down.”