#Module10 #EID100: Technological breakthrough — Penicillin
Penicillin is an antibiotic that was discovered in 1928 by Alexander Fleming, Professor of Bacteriology at St. Mary’s Hospital in London (Markel, 2013). The discovery was accidental. “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 (Markel, 2013).”
Penicillin prevents the growth of of gram positive bacteria (bacteria that have their cell wall exposed) by preventing them from synthesizing their cell wall. Penicillin does not work on gram negative bacteria because their cell wall is protected by a layer of cellular membrane as shown below:
Penicillin was the first antibiotic. Before its mass production in the 1940’s, there was no way to prevent bacterial infections (Markel, 2013). Conveniently enough, penicillin was mass distributed just in time to treat soldiers’ wounds in World War II.
The species of Penicillium that Fleming discovered (Penicillum notatum) to produce the antibacterial penicillin did not remotely produce enough penicillin to mass produce and sell. Decades after the initial discovery, a species of Penicillum, Penicillium chrysogeum, was discovered to produce 200 times the amount of penicillin when compared to Penicllum notatum (Markel, 2013). This species was further mutated by X-ray to produce 1000x the amount of penicillin compared to Penicillum notatum and was used to produce penicillin at large.
Citation:
Markel, H. (2013, September 27). The real story behind penicillin. Retrieved November 22, 2016, from http://www.pbs.org/newshour/rundown/the-real-story-behind-the-worlds-first-antibiotic/