Eli5: How is penicillin created from something potentially toxic such as mold?

Question

Eli5: How is penicillin created from something potentially toxic such as mold?

In: 4

Answer 1

The mold that makes penicillin produces it to protect itself from bacteria. We can isolate the penicillin and use it for our own antibiotics.

Remember mold is a type of fungus and there are many, many species. Some are beneficial like the mold we use in cheese-making, or are harmful like black mold that can grow in houses and cause respiratory illness. Many are neutral. Very diverse group of organisms.