Bacterial enzymes degrade plastic soda bottles

A new process for breaking down plastic bottles is in the works based on a combination of two enzymes that are produced by a species of bacteria that was discovered in Japan in 2016, the New York Times reports.

The research is published in the open-access journal Proceedings of the National Academy of Sciences, or PNAS.

As our energy consumption turns away from the burning of fossil fuels, derived from oil, energy companies have sought other uses for the excess supply of oil they have on hand. One use has been to make the plastic known as PET (polyethylene terephthalate), which is commonly found in soda bottles, synthetic clothing, and other materials.

An estimated 359 million tons of plastic is produced annually worldwide, The Times reported, with at least 150 million tons of it sitting in landfills or in the environment.

The soda bottles can also make their way to the ocean, where they take hundreds of years to dissolve. That has led to a build-up of plastic garbage in the ocean, and from there, it has made its way into our food supply through the fish that eat small pieces of it.

The Great Pacific Garbage Patch

Many teams are working on different approaches to combat the plastic issue, including the development of biodegradable plastics, which brings us to the current research.

Using one enzyme from the bacterium Ideonella sakaiensis, named PETase because it breaks down PET by depolymerizing it, moves the recycling process along slowly but surely—plastic degrades in a few weeks. But when researchers add METase to the mix, the PET breaks down much more quickly and, in fact, is converted back to the original substance so it can be reused to make more bottles.

“You get the original building blocks back,” The Times quoted Professor John McGeehan, director of the Center for Enzyme Innovation and co-leader of the team, as saying.

But just having a working cocktail of enzymes doesn’t solve the whole problem. We still have to get the plastic bottles to the facilities where they can be broken down.

Still, it’s nice to know we have a way to recycle it completely if we can get it to the recycling centers instead of throwing it into the ocean.