Natural clean-up: Bacteria can remove plastic pollution from lakes
A freshwater lake in Norway, one of 29 European lakes that were part of the study. Credit: Samuel Woodman

According to a study of 29 European lakes, some naturally-occurring lakebacteria grow faster and more efficiently on the remains of plastic bags than on natural matter.

The carbon compounds in plastic are broken down by thebacteria.

According to the scientists, enriching waters with certain species ofbacteria could be a way to remove plastic pollution from the environment.

When plastic pollution raised the carbon level in the lake water, the rate ofbacterial growth more than doubled.

The results show that the plastic pollution in the lakes is making thebacteria more efficient in breaking down carbon compounds in the lake.

Plastic-derived carbon compounds were preferred by the lakebacteria. The researchers think that the carbon compounds from plastic make it easier for thebacteria to break down and eat.

Scientists caution that this doesn't condone plastic pollution. Toxic effects on the environment can be caused by some of the compounds in plastic.

Today's findings are published in the journal.

It's almost like the plastic pollution is making thebacteria want to eat it. The natural organic matter in the lake is harder to break down than the plastic because it's easy to break down.

He said that this suggests that plastic pollution is stimulating the whole food web in lakes.

The effect was different depending on the variety ofbacteria present in the water.

Natural clean-up: Bacteria can remove plastic pollution from lakes
A freshwater lake in Norway, one of the 29 European lakes analyzed as part of the study. Credit: Andrew Tanentzap

According to a study published last year, European lakes are a potential source of micro plastic pollution.

Carbon compounds are released when plastic breaks down. These are different from the carbon compounds released as organic matter.

The carbon compounds from plastic were derived from different types of plastic.

More plastic pollution was removed from lakes that had fewer unique carbon compounds. The lake water has less other food sources than other places.

Pollution control will be prioritized by the results. If a lake has a lot of plastic pollution, it will be more vulnerable to damage.

Plastic pollution will affect our environment for a long time. "Our study helps to identify microbes that could be harnessed to help break down plastic waste and better manage environmental pollution," said Professor David Aldridge, who was involved in the study.

Sampling was done on 29 lakes across the country. The lakes had different latitude, depth, area, average surface temperature, and dissolved carbon-based molecule diversity.

The scientists shook the plastic bags in the water to release their carbon compounds.

The bottles were filled with water. A small amount of the 'plastic water' was added to half of the others, to show how much carbon was taken from the environment by the use of plastic. The bottles were emptied after 72 hours of darkness.

By measuring the amount of carbon-dioxide released in the process of growing, the study was able to measure the efficiency ofbacterial growth.

The plastic-derived carbon compounds in the water doubled the mass of thebacteria very quickly. In 72 hours, half of the carbon was incorporated into thebacteria.

Our study shows that when carrier bags enter lakes and rivers they can have a big impact. Eleanor is the first author of the study who undertook the work as part of a final-year undergraduate project.

More information: Eleanor Sheridan, Plastic pollution fosters more microbial growth in lakes than natural organic matter, Nature Communications (2022). DOI: 10.1038/s41467-022-31691-9. Journal information: Nature Communications