Mouldy bread and an illustration of the microscopic fungi Penicillium, which causes food spoilage and produces the antibiotic penicillin. There are over 100 species of Penicillium, a number of which cause food decay. Air-borne spores alight on the food and germinate, absorbing nutrients for growth via radiating filaments called hyphae. Each mass of hyphae, called a mycelium, generates aerial branches bearing fruiting bodies consisting of new spores. These appear green in the case of Penicillium and green, blue, yellow or black in the case of other Plectascales. The new spores are dispersed by air movements. |