In 2016, Japanese scientists discovered the first bacterium that had naturally evolved to eat plastic at a waste dump. Scientists have now revealed the structure of the crucial enzyme produced by the bug. After tweaking it to see how it had evolved, they inadvertently made the molecule even better at breaking down PET (polyethylene terephthalate) used for soft drink bottles.
Prof John McGeehan, at the University of Portsmouth, UK, who led the international research team along with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), describes the finding in the newspaper The Guardian as ‘a bit of a shock’, and adds ‘what we are hoping to do is use this enzyme to turn plastic back into its original components, so we can literally recycle it back to plastic.’
Earlier work has shown that some fungi can break down PET, but bacteria are easier to harness for industrial uses.
The paper, ‘Characterization and engineering of a plastic-degrading aromatic polyesterase,’ will be published this week in the Proceedings of the National Academy of Sciences (PNAS).