About 1 million plastic bottles are purchased every minute. Only 14% of these are recycled worldwide. The rest end up in landfills or, worse, pollute the ocean. PET is inert by design, and lasts millions of years.
In 2016, a species of bacteria was genetically engineered to eat plastic. The bacteria use an enzyme (a biochemical catalyst) that breaks down the plastic and turns it into liquids that can be used like kerosene or gas.
Tweaking the enzyme, a group of University of Portsmouth scientists stumbled on a form that is more efficient than what the bacteria used. It can break down PET in just a few days.
"It is a modest improvement -- 20% better -- but that is not the point," said McGeehan. "It's incredible because it tells us that the enzyme is not yet optimised. It gives us scope to use all the technology used in other enzyme development for years and years and make a super-fast enzyme."