Mold is pervasive in our environment; it occurs indoors
and outdoors. In nature, various molds work to decay leaves and trees, returning
essential nutrients back into the soil. Mold has also served humankind through
some very inventive applications. Experiments in the 1920s revealed that a
species of mold, called Penicillium, when added to a sweet solution, released a
chemical as part of its metabolic processes. That chemical became known as
penicillin, a live-saving antibiotic. Molds also have a long history of use in
cooking: they are essential to production of some cheeses such as blue cheese.
Airborne molds and yeasts provide the leavening agent and distinctive flavour of
sourdough bread. Inside our homes, however, mold can cause serious health
problems and damage building structures.