Penicillium. Coloured Scanning Electron Micrograph (SEM) of the mycelium and fruiting bodies of the fungus Penicillium sp. Penicillin mould grows as a mycelium of hyphal threads, as seen here in the background. In the foreground (centre) is a hyphal branch which bears fruiting bodies at its tip, known as conidia. These tuft-like clusters of conidia contain rounded spores strung together in chains. Once ripe each spore can germinate into a new fungus. Species of Penicillium are the source of antibiotic penicillin for use as drugs to combat bacterial infection. They are also used in the fermentation of roquefort & camembert cheeses. Magnification: x1200 at 6x7cm size. x2,000 at 4x5ins