Fellow humanoids, our task is nearly complete. We’re now annually making more than 50 million tons of polyethylene terephthalate or PET plastic. We’ve been at it a while: The land is garlanded, the oceans spiced. Thanks to us, the food supply for the Earth’s next overlord is almost ready.
Ideonella sakaiensis, a species of bacteria that seems to have evolved inside a PET recycling facility, is now ready to start eating. Shosuke Yoshida at Kyoto University and his colleagues report in Science that the species possess two enzymes that allow the bacteria to use PET plastic as their only source of carbon. The bacteria glue themselves to the plastic and secrete the first enzyme. They then draw the ooze that results from this digestive process into their cells where the second enzyme finishes the work. The whole process takes six weeks, an eternity in the bacterial world, but we can expect efficiencies to develop as the bacterium develops a better work ethic.
Only 14% of plastics worldwide are recycled, so Ideonella arrived into a world that any astute student of biotheology would surely recognize as designed specifically for the eventual evolution and triumph of the species.
In a commentary on the paper, Uwe Bornscheuer of the Department of Biotechnology and Enzyme Catalysis, Greifswald University, states that if the leftovers of the bacterial digestive process “could be isolated and reused, this could provide huge savings in the production of new polymer without the need for petrol-based starting materials”. In other words, we’ll be able to keep making PET plastic even when the oil runs out. Ideonella will no doubt be thankful.