Penicillin is not a fungus. Thanks for your effort.
yeast
“What is the most important fungus the world has ever known?”
Government?
Certainly, it is the most self-important.
Penicillin was initially derived from a fungus ....
Yeast.
Botrytis cineria
“Upon examining some colonies of Staphylococcus aureus, Dr. Fleming noted that a mold called Penicillium notatum had contaminated his Petri dishes. After carefully placing the dishes under his microscope, he was amazed to find that the mold prevented the normal growth of the staphylococci. Penicillium chrysogenum or P. notatum (formerly) is a species of fungus in the family Trichocomaceae.”