New bacteria eats plastic: Researchers Have Discovered a Bacteria That’s Evolved to Eat Plastic

Updated: March 12, 2016
New bacteria eats plastic: Researchers Have Discovered a Bacteria That's Evolved to Eat Plastic

A team of Japanese scientists discovered a strain of bacteria that can eat a certain type of plastic, known as PET, which is commonly found in disposable water bottles.

Prof. Dr. Uwe Bornscheuer from the German University of Greifswald says that there are about 56 million tons of PET produced worldwide in 2013 alone, and the accumulation of PET in ecosystems around the globe is increasingly problematic.

So far science found a some species of fungi that have been found to break down PET. The research team around Shosuke Yoshida identified the first bacteria that is into eating plastic.

By screening natural microbial communities exposed to PET in the environment, the Japanese scientists isolated a novel bacterium,6, that is able to use PET as its major energy and carbon source.

When grown on PET, this bacteria strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. The two enzymes are named PETase and METase. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol.

It takes the Ideonella sakaiensis 201-F6 bacteria degrade a thin film of PET after six weeks at a temperature of 30°. Further investigation identified an enzyme, ISF6_4831, which works with water to break down PET into an intermediate substance, which is then further broken down by a second enzyme, ISF6_0224. These two enzymes alone can break down PET into its simpler building blocks. Remarkably

Prof. Dr. Uwe Bornscheuer, who wrote a perspective on the ground-breaking Japanese discovery says: “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.”

It is not clear how long it would take to industrialize a bacteria based PET waste solution. An industrial solution could also be based on the identified enzymes that break down the plastic. The detailed mechanism on how exactly the Ideonella sakaiensis bacteria is able to break up the surface of PET plastic is not fully understood yet by the scientists. There is more ground work necessary.

The full details of the research have been published in the paper titled “A bacterium that degrades and assimilates poly(ethylene terephthalate)” authored by Shosuke Yoshida, Kazumi Hiraga, Toshihiko Takehana, Ikuo Taniguchi, Hironao Yamaji, Yasuhito Maeda, Kiyotsuna Toyohara, Kenji Miyamoto, Yoshiharu Kimura and Kohei Oda in Science Journal.