Magic mushrooms

Mycologists have discovered fungi that can break down polyethylene, the sort of plastic typically used in shopping bags, food wraps and bottles.

These are a small number of species of fungi that can rot hardwoods, which are very resistant to decay. The fungus is able to degrade the lignin, a polymer that is an essential part of the structure of wood. Lignin is the hardest natural polymer on Earth and researchers decided that any fungus that can produce the sort of enzymes needed to break down lignin might be worth trying out on our growing mountain of plastic waste.

Fungi in a petri dish and an oak tree, one of the reserve’s hardwoods.

From rotting hardwood they isolated 21 species of fungus, each of which they incubated with sheets of polyethylene at temperatures between 28°C and 30°C for 45 days. The polyethylene weighed less after exposure to the fungi compared with before.

While we onlookers might crave a little more drama and banner headlines forl our breakthroughs, science works slowly and carefully and really doesn’t enjoy a fuss. The experiment shows that the fungi have metabolised the polyethylene: in news-speak, the mushrooms have eaten the plastic. Magic!