A species of fungus found in soil can be fed to cows to cut down on the potent greenhouse gas methane in their burps.

“It’s a fungal soup,” says Matthew Callaghan at Roam Agricultural, a startup in Australia aiming to grow large amounts of the fungus in bioreactors. Instead of feeding cows the fungi directly, however, the company plans to extract the methane-reducing compound they make – called bromoform – and add it to feed…