Scientists have created a mutant enzyme that breaks down plastic drinks bottles and it all happened by accident. This incredible enzyme could be used as a future solution to the millions of tonnes of plastic that enters the world’s oceans each year, which currently remain in the environment without breaking down for hundreds of years.
The new research was spurred by the discovery in 2016 of the first bacterium that had naturally evolved to eat plastic, at a waste dump in Japan. Scientists have now revealed the detailed structure of the crucial enzyme produced by the bug.
The international team then tweaked the enzyme to see how it had evolved, but tests showed they had inadvertently made the molecule even better at breaking down the PET (polyethylene terephthalate) plastic used for soft drink bottles.
The mutant enzyme, catchily known as Ideonella sakaiensis 201-F6,takes a few days to start breaking down the plastic – far faster than the centuries it takes in the oceans. But the researchers are optimistic this can be speeded up even further and become a viable large-scale process.
Currently, 1,000,000 plastic bottles are sold each minute around the world and we recycle just 14 percent of that, much of the rest ending up in the ocean and that is slowly becoming a giant pot of animal-killing plastic soup. Also the problem with the recycled plastic is that it can only be turned into fiber that is used in other applications; think carpeting, fleece and tote bags.
With the new enzyme, however, the idea is it that it can be put to use to turn old plastic into new plastic.
“What we are hoping to do is use this enzyme to turn this plastic back into its original components, so we can literally recycle it back to plastic… It means we won’t need to dig up any more oil and, fundamentally, it should reduce the amount of plastic in the environment.” says structural biologist John McGeehan from the University of Portsmouth in the UK.
In the meantime. the world continues to churn out 300 million tonnes of plastic every year. By 2050, plastic waste in the oceans is expected to outweigh fish. There are no easy ways, but novel solutions such as this are offering a glimmer of hope in our mammoth battle ahead against plastic pollution
The findings are reported in Proceedings of the National Academy of Sciences