At the Paddestoelen Paradijs exhibition we've been researching and playing around with how to use mushrooms to replace plastics, but fungus has surprised us once again. This surprisingly versatile organism can also be used to breakdown plastics, like polyurethane, that are filling up our landfills. The low cost and easy manufacturing of synthetic polymers has increased global plastic demand more than 150-fold since 1950, with production growing from 1.5 million tons to 245 million tons as of 2006. Once this common plastic gets into our trash stream it persists for generations, outliving all of us.
There were already known fungi and bacteria that can break down plastic, but students of Yale University recently discovered that the pestalotiopsis microspora from the Amazon forest can do this much faster and more effectively. The group searched for plants in Equador, and then cultured the microorganisms within the plant tissue back at the lab. As it turns out, they brought back a newly discovered fungus with a voracious appetite for a global waste problem: polyurethane. The fungus basically eats the plastic and breaks it down into carbon.
The fungus, Pestalotiopsis microspora, was found in a particular type of guava plant by a student in 2008. Other students followed up on this discovery and found that not only does the fungus break down polyurethane, but it can do it in the depths of a landfill. The fungus can decompose the plastic anaerobically, which means without oxygen. This is perfect for landfills which have very low oxygen levels at their depths. Who knows, maybe in the future our trash compactors may simply be giant fields of voracious fungi.