The fuzzy green carpet that appears to be covering your bread, fruit, or vegetables when they’ve been around just a bit too long is called mold. Molds are a type of fungus, a microorganism—that is, a tiny living thing—made up of multiple cells growing in long strands called hyphae. The fuzzy mass that the hyphae create is called the mycelium.
Molds as Decomposers
As living things are born, grow, and eventually die, something must happen to the waste produced by these living things, as well as to their bodies when they die. Molds are partially responsible for the breakdown and digestion of this litter, and so they facilitate the return of the nutrients contained within these living things back to the soil. If molds and other microorganisms could not do this, the nutrients contained in the bodies of dead plants and animals would remain there forever, and the soil would never get them back, making it impossible for new plants to grow, and new animals to be fed.
Molds in food production
Molds are traditionally used in the production of a variety of different foods, such as soy sauce, cheese, and salami. The molds break down the sugars and starches of the soy and milk, allowing them to ferment (a process which turns sugars into acids, alcohols, and gasses), which improves the nutrition, flavor, and/or shelf life.
Molds making medicines
One of the most important discoveries of the 20th century was the discovery of penicillin, one of the first antibiotic drugs to be used widely, and which was of great importance during World War II (see Reference 3 for more information). Penicillin is produced by a group of molds called Penicillium, and is still used today.
Another medicine that is produced by molds includes the immune suppressing drug called cyclosporine, which is used to prevent patients’ bodies from rejecting newly transplanted organs (like lungs or hearts). Cyclosporine is produced by the mold Tolypocladium inflatum, originally found in Norwegian soil. Several cholesterol lowering drugs are also made by molds.
While most molds are not dangerous to the average person, if enough mold is present in the surroundings it can make you sick. There are also some types of mold that are extremely dangerous, producing toxic compounds that can cause nerve damage and even death. These are not present everywhere, but it is always best to be safe, and avoid exposure to homes or other buildings with lots of mold growth.
GROW A PET MOLD!
Here’s what you’ll need:
1. A piece of bread, preferably homemade or from a local bakery
2. A zip top bag
3. A pair of scissors
4. A warm, dark cupboard that is NOT used to store food
Here’s what you need to do:
1. Place your piece of bread inside the zip top bag, and close it carefully
2. Cut a few very small slits in the bag to allow air circulation
3. Place the bag in the cupboard, and make sure no one eats the bread!
4. Allow the bread to rest undisturbed for at least a few days, then up to a few weeks, checking it daily.
What did the bread look like after two or three days? After one week? After two weeks? Write down everything you observe in your journal, and take pictures of the bread every few days if you can; pictures are a great way to record changes!
References for further reading:
1. “Mold.” Wikipedia. September 12, 2014. Viewed on 9/16/14. http://en.wikipedia.org/wiki/Mold#Pharmaceuticals_from_molds
2. Campbell, N.A.; Reece, J. B.; Mitchell, L. G. Biology, 5th ed (1999). Addison Wesley Longman, Inc. Menlo Park, CA.
3. “Penicillin.” Wikipedia. September 16, 2014. Viewed on 9/16/14. http://en.wikipedia.org/wiki/Penicillin#History
4. “Tolypocladium inflatum.” Wikipedia. July 29, 2014. Viewed on 9/16/14. http://en.wikipedia.org/wiki/Tolypocladium_inflatum
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