Microbes Evolve to Eat Plastic Waste

Scientists have discovered bacteria that can break down plastic.

Plastic waste is an increasing concern, as millions of tonnes of plastic waste end up in oceans, on our beaches, and even near the summit of Mount Everest. However, new research from Chalmers University of Technology, Sweden, has found that microbes are adapting to break down plastic waste.

The team leading this research took samples of environmental DNA from locations around the world. This environmental DNA can be seen in natural materials including seawater, soil, or snow, and it shows which organisms have been interacting with that area, because of the DNA they leave behind. In these samples, scientists were looking to find evidence of microbial enzymes that have the capacity to degrade plastics. These microbial enzymes are a form of protein produced by microorganisms and have the ability to speed up reactions. The enzymes scientists found in the environmental DNA have the ability to break down plastics at a faster rate.

Once the plastic-degrading enzymes had been identified, teams compared their results with official numbers of plastic waste pollution worldwide and found an interesting correlation. Aleksej Zelezniak, associate professor of Systems Biology at Chalmers University, explained that the research team “found multiple lines of evidence supporting the fact that the global microbiome's plastic-degrading potential correlates strongly with measurements of environmental plastic pollution.” Put simply, Zelezniak and his team found that there were more plastic-degrading organisms in places with higher plastic pollution.

The research from Zelezniak and Chalmers University was published in mBio, and this information could form the basis of a new method of fighting plastic pollution. The microbes’ ability to adapt to break down plastic is “a significant demonstration of how the environment is responding to the pressures we are placing on it.”

With so much plastic waste finding its way to our oceans and taking hundreds of years to degrade, it is important that scientists are finding ways around this. Zelezniak explains that the next steps of this research would involve closely monitoring enzymes to understand their properties and the rate at which they degrade plastic. Then, Zelezniak said that “you could engineer microbial communities with targeted degrading functions for specific polymer types.”

This is brilliant news for fighting plastic waste worldwide: once Zelezniak and his team have a better understanding of the properties of plastic-degrading enzymes, we are likely to see them introduced to environments where plastic pollution is worryingly high, to help the existing microorganisms that have adapted to produce these enzymes.

While this new technology is being developed further, we can all do our bit to reduce our impact on the planet. The carry-in/carry out philosophy that so many hikers and surfers believe in should be adopted by users of UK coasts; we’d see a reduction in waste left behind. To further reduce your impact on coastlines and coastal ecology, take part in a beach clean, reuse carrier bags, or visit your local refill shop.