Every year we discard millions of tons of plastic that take decades or centuries to degrade, so it's good news that the scientific community is working to find new ways to process and recycle plastic.
There are some bacteria (ideonella sakaiensis) discovered in Japan that were learned to feed on plastic, since it was the only thing around them. The discovery of these bacteria was the first step, the next step was to identify how they managed to do this, isolate the substance and see how we could use this amazing capacity to our advantage.
The enzyme of this bacterium that makes this marvel work is currently being studied, its name is PETase. This enzyme doesn't eat any plastic, it specializes in one called Polyethylene Terephthalate (PET). This is the plastic from which the bottles and many containers are made.
The group of scientists who are researching this enzyme have proven that the 3D structure of this enzyme is very similar to other enzymes that bacteria use to digest fat, wax and also to digest the cuticles that protect the leaves of plants. That kind of wax that makes some plant leaves water-resistant.
All these substances have one thing in common, they form very long molecules that are very difficult to separate chemically and that's precisely what they have in common with plastic, so it's concluded that this enzyme wasn't created from scratch but already had these weapons to attack these polyesters.