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How Illinois Mold Saved the World

Peoria IL

Gather ‘round the computer screen, as I recite a tale of yore. Way off in a dark and mysterious land known as “Peoria, Illinois” (my hometown) comes the legend of Moldy Mary, and how her magic spoiled fruit helped save millions of lives. This may sound like the talk of storybooks and tall tales… you aren’t likely to see her name in history books. Moldy Mary, born Mary Hunt, was a real person who played an invaluable role in the commercialization of the antibiotic drug Penicillin, which is one of the most important scientific discoveries of the 20th century. Illinois mold may very well have saved the world! Well, not quite, but it has help save millions of lives!

Many people know of Brittish microbiologist Alexander Flemming. In 1928 he discovered that random Penicillium mold spores that landed and started growing in his Petri dishes were limiting the growth of the surrounding bacteria that he was trying to study. He ultimately would share the Nobel Prize in Medicine in 1945 for his part in this discovery. In 1939 Brittish scientists at Oxford started serious research into the pharmacological applications of Penicillium, however, the team was unable to produce Penicillium mold with a high enough concentration of penicillin for widespread trials and manufacturing. With the cost of WWII putting a strain on the Brittish government, they turned to scientists in the United States who were working with fermentation to increase microbial growth.

In 1941 the researchers at the USDA Northern Regional Research Laboratory in Peoria, Illinois worked on a method where Penicillium mold was grown in vats using a corn by-product1. Using Penicillium cultures from all over, the lab started to fine-tune the culture process and worked to find strains of Penicillium that produced larger quantities of the penicillin compound. By a serendipitous chance, the source of the strain that produced the highest concentration of penicillium came from a moldy cantaloupe found at a fruit market not far from the lab. It was brought into the lab by Mary Hunt, who from varying reports was either a laboratory employee or a local housewife. She noted a “pretty, golden mold” on the rind of the melon, from which the culture generated nearly 1000x the amount of penicillin compared to the strain the British scientists were using. Now, we can not say that Mary is the reason over 200,000,000 people’ lives were saved, but the work done at the USDA lab in Peoria was monumental to the rapid industrialization of penicillin. In 1942, 400 million doses of penicillin had been manufactured and by the end of 1945, over 650 billion doses were being manufactured per month2.

Even with all of the amazing industrial uses for mold, if you see it growing in your home, that is an issue. Check out our mold testing services and contact us to help assess your mold issue. We aren’t likely to contribute to any groundbreaking discovery the way Moldy Mary and her cantaloupe were, but we can help identify and solve mold and moisture issues affecting your home.

  1. https://www.ars.usda.gov/midwest-area/peoria-il/national-center-for-agricultural-utilization-research/docs/penicillin-opening-the-era-of-antibiotics/
  2. https://www.pbs.org/newshour/health/the-real-story-behind-the-worlds-first-antibiotic

Ian Cull

Ian Cull is a nationally recognized expert in the field of indoor air quality. He is the Chief Science Officer of Indoor Science, a company he started in 2004. He speaks around the world on air quality topics and is a training provider of the Indoor Air Quality Association. Mr. Cull is a Licensed Professional Engineer (PE) and Certified Industrial Hygienist (CIH). His degree is in Environmental Engineering from the University of Illinois - Urbana Champaign. Mr. Cull has developed 50 air quality related courses for the IAQA University and is the author of the book, “Fundamentals of Mold Remediation”. In his words… “Besides being passionate about indoor air quality, I enjoy cycling, music, the Chicago Bulls, and having fun with my three kids.”

One thought on “How Illinois Mold Saved the World

    Great story! I never heard about Moldy Mary. The work of Alexander Fleming is talked up so much that the other characters get eclipsed. Is she the unknown Rosalind Franklin of the antibiotics world? Another moldy story of my own: I learnt to make sourdough bread from my daughter. Stage one is to revive the culture by adding flour and water and let it incubate for 6 hrs. This must be done UNCOVERED so as to maximize the re-inoculation with local airborne molds.