Scientists have created a mutant enzyme that breaks down plastic drinks bottles by accident. The breakthrough could help solve the global plastic pollution crisis by enabling for the first time the full recycling of bottles. 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 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. Industrial enzymes are widely used in, for example, washing powders and biofuel production. They have been made to work up to 1,000 times faster in a few years, the same timescale [Prof John McGeehan, who led the research] envisages for the plastic-eating enzyme. Earlier work had shown that some fungi can break down PET plastic, which makes up about 20% of global plastic production. But bacteria are far easier to harness for industrial uses.