Recycling is so 20th century. According to one new study, there could be a new way to cut down on plastic waste: bacteria that consume one of the major components of our old bottles and clothes.
The study, published Thursday in Science, focuses on a newly-discovered bacterium called Ideonella sakaiensis. It was found outside of a bottle recycling plant, and it seems to have evolved a pair of enzymes it uses to break down polyethylene terephthalate or PET, a polymer so widely used to make plastic that about 50 million tons of it are made every year.
Because 311 million tons of plastics are produced worldwide each year — and very little of that amount makes it to recycling plants — scientists are always on the lookout for new, better ways of making PET break down when it inevitably ends up in landfills, but it's tough stuff.
"You may think this is the rerun of an old story, as plastic-eating microbes have already been touted as saviors of the planet," the University of Hull's "But there are several important differences here. First, previous reports were of tricky-to-cultivate fungi, where in this case the microbe is easily grown. The researchers more or less left the PET in a warm jar with the bacterial culture and some other nutrients, and a few weeks later all the plastic was gone."
The impressive results don't mean that we can start tossing plastic bottles into landfills all willy-nilly: It's going to take some more work before the bacteria are ready to tackle our messes. For now, they still have a hard time breaking down the highly crystallized form of PET used in most hard plastics.
“It’s difficult to break down highly crystallized PET,” study author Kenji Miyamoto of Keio University told The Guardian. “Our research results are just the initiation for the application. We have to work on so many issues needed for various applications. It takes a long time."
And there are other potential hiccups: If plastics were broken down using bacterial processes, they might release unsavory molecules and compounds into the environment that would otherwise stay locked up.
But even if there's no direct use for Ideonella sakaiensis in our environment, the bacteria's mechanism for consuming PET could be used to develop synthetic plastic-chompers in the lab. And the bacteria's existence is a great sign: PET has only been around for about 70 years, and this indicates that at least one organism has already evolved the ability to consume it. It's likely that there are other microbes out there doing the same thing for PET and other kinds of plastics — and one of those species could wind up revolutionizing the way we recycle.