Plastic can be useful, but managing the deluge of what is discarded every day is one of the challenges of modern times. It’s estimated that more than 300 million tons of plastics are produced each year. Recycling efforts help, but only about 14 percent of all plastics are collected and recycled, so plenty of plastic ends up in landfills and oceans (think: Great Pacific Ocean Garbage Patch), where it will stick around for decades if not centuries. But what can we do about it?
How about eating it? Japanese scientists from the Kyoto Institute of Technology and Keio University have found a special bacteria that likes to eat polyethylene terephthalate, better known as PET plastic. It’s one of the most common variants and is used for consumer products like water bottles, soft drink bottles, polyester clothes, packaging and more.
In a new paper published in the journal Science, the researchers describe searching for the special microbes where they were most likely to be found: Near a plastic bottle recycling facility. They collected 250 PET-contaminated soil and wastewater samples from the site and analyzed them. One of the bacteria was growing by eating the PET plastic using two enzymes to break it down into intermediate chemicals that it can then further degrade into the carbon and energy that it needs to sustain life and grow.
The researchers named the new plastic eater Ideonella sakainesis. They found that the microbes could break down a thin film of PET over six weeks given a stable temperature of 86 degrees Fahrenheit. This proved to be more effective than a type of hard-to-grow fungi that had previously been found to consume PET.
But let’s not prematurely celebrate the end of our plastic problem. This bacteria might be useful in some situations, and now that we know it exists, we might be able to find others that are even more effective at degrading common plastics like PET. Ideally, the enzymes that break down the plastic could be isolated and made much more effective, so that a new kind of plastic recycling plant could be created where plastics would be literally broken down into their constituent chemicals.
But we’re not quite there yet. For now, we need to focus on reducing our plastic use as much as possible, and make sure that what we do use ends up in the recycling bin.