Scientists found a fungus in the Amazon called Pestalotiopsis microspora that literally snacks on plastic.
Pestalotiopsis microspora is not your typical fungus. It can survive entirely on polyurethane, one of the most common (and most persistent) types of plastic — and it does so even in oxygen-free environments, like buried landfills.
[Khan, Sehroon, et al. “Biodegradation of Polyester Polyurethane by Aspergillus tubingensis.” Environmental Pollution, vol. 225, Mar. 2017, pp. 469–480] 