Bacteria that feast on plastic offer solution to pollution

BACTERIA with a taste for supermarket plastic bags could end the scourge of microplastic in lakes, after scientists found some bacteria actually thrive on polyethylene pollution.

Researchers at Cambridge University studied water from 29 lakes in Scandinavia and discovered that chemicals leached from plastic bags stimulate bacterial growth.

Naturally occurring lake bacteria, such as Deinococcus and Hymenobacter, find it easier to extract carbon from the broken-down plastic than from natural organic matter such as twigs and leaves, the study showed. The bacterial boost has a knock-on effect for the whole food chain, eventually providing extra nutrition for the other lake-dwellers.

Although scientists say nobody should purposefully add plastic to lakes, enriching waters with particular species of bacteria could be a natural way to remove pollution from the environment, they believe.

“It’s like the plastic pollution is getting the bacteria’s appetite going,” said Dr Andrew Tanentzap of Cambridge’s department of Plant Sciences, the senior author of the research. “The bacteria use the plastic as food first, because it’s easy to break down, and then they’re more able to break down some of the more difficult food – the natural organic matter in the lake. This suggests that plastic pollution is stimulating the whole food web in lakes... more bacteria means more food for bigger organisms like ducks and fish.”

Scientists cut up plastic bags from four major shopping chains in the UK, and shook them in water until their carbon compounds were released. They then mixed the water with water from lakes and measured bacterial activity after 72 hours. Within just three days, about 50 per cent of this carbon leached from the bags had been taken up by the bacteria.

The authors caution that their study is focused solely on bacteria and does not take into consideration the effect of plastic on other microorganisms, such as microalgae and fungi.

The research was published in the journal Nature Communications.