A type of bacteria that eats plastic could assist recycling centers in degrading bottles and other waste for reuse in new products. It was recently discovered during testing on material from a recycling plant, where the lifeforms were found to be eating away plastic waste.
Polyethylene terephthalate (PET) is a commonly-used form of plastic that is particularly difficult to recycle. Approximately 51 million tons of products were manufactured in 2013 alone. That material, a member of the polyester family, is commonly used in food packing and clothing. Also known as Dacron, it was first patented in 1941.
The newly discovered bacteria consume the plastic, leaving behind simple chemical building blocks. Biologists found the bacteria use a single pair of enzymes to break down plastics, consuming energy in the process. The pair of enzymes used in the process appears to have a novel approach to gathering nutrients from the world around them, suggesting a larger mystery.
"These two enzymes alone can break down PET into its simpler building blocks. Remarkably, these enzymes seem to be highly unique in their function compared to the closest related known enzymes of other bacteria, raising questions of how these plastic-eating bacteria evolved," The American Association for the Advancement of Science reports.
One enzyme, ISF6_4831, starts to break down PET into smaller building blocks, while ISF6_0224 completes the process. When completed, the bottles can be converted entirely into carbon dioxide and water. It is capable of consuming a thin film of PET in just six weeks when kept at 86 degrees Fahrenheit. Future research will examine how these bacteria may be adapted to break down larger masses of PET's for commercial use.
Previously, researchers have only found a few species of fungi capable of digesting PET. This is the first bacteria known to consume the common plastic. After examining 250 samples of PET, investigators who found the previously-unknown life form named the new variety of bacterium Ideonella sakaiensis 201-F6.
Worldwide, about 342 million tons of total plastics are created each year, and only about 14 percent of these materials are gathered for recycling annually.
The discovery of the newly-recognized bacteria and investigation of their ability to consume PET was published in the journal Science.
Image: Keoni Cabral | Flickr
