Plastic pollution has become a big problem thanks to humans’ shenanigans, but we might be about to get a helping hand from bacteria. A study that looked at 29 European lakes has discovered that certain types of bacteria are actually mad for plastic, and will grow better among our toot than they do amidst natural detritus like leaves and twigs.
Why are the bacteria so hot for plastic, I hear you ask? Compared to organic material, it seems they’re better able to break down the carbon compounds plastics release into the water, which they then turn into food.
The lake study, published in the journal Nature Communications, sampled 29 bodies of water across Scandinavia between August and September 2019. The lakes tested differed in their traits, meaning the results represent a varied group involving different depths, temperatures, and bacterial diversity.
After shaking some plastic bags in water (to release their carbon compounds), lake samples were collected and the two were combined and taken back to the lab. Under ultra-high resolution mass spectrometry, these samples were compared against controls to see what the bags were leaching and how bacteria might use it.
Their results showed that the compounds released by the plastic bags were chemically distinct and more easily accessible to bacteria compared to those dumped by organic matter, enhancing growth by 1.72 times.
“It’s almost like the plastic pollution is getting the bacteria’s appetite going," said senior author Dr Andrew Tanentzap in the University of Cambridge’s Department of Plant Sciences, in a statement. "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, because more bacteria means more food for the bigger organisms like ducks and fish.”
While the findings are limited in that they are specific to bacteria and don’t factor in other organisms, such as microalgae and fungi, they point us in a promising direction for bacteria species that could be superheroes when it comes to clearing bodies of water of plastic. Deinococcus and Hymenobacter were two such candidates, both of which occur naturally in lake environments.
“Unfortunately, plastics will pollute our environment for decades,” said Professor David Aldridge of University of Cambridge’s Department of Zoology, who was involved in the study. “On the positive side, our study helps to identify microbes that could be harnessed to help break down plastic waste and better manage environmental pollution.”