The History of Penicillin

Alexander Fleming, John Sheehan, Andrew J Moyer

Nurse taking stock of pharmaceutical drugs
Smith Collection/ Iconica/ Getty Images

Penicillin is one of the earliest discovered and most widely used antibiotic agents, derived from the Penicillium mold. Antibiotics are natural substances that are released by bacteria and fungi into their environment, as a means of inhibiting other organisms - it is chemical warfare on a microscopic scale.

Sir Alexander Fleming

  • Born August 6, 1881, in Darvel, Scotland
  • Died March 11, 1955, in London, England

In 1928, Sir Alexander Fleming observed that colonies of the bacterium Staphylococcus aureus could be destroyed by the mold Penicillium notatum, proving that there was an antibacterial agent there in principle. This principle later led to medicines that could kill certain types of disease-causing bacteria inside the body.

At the time, however, the importance of Alexander Fleming's discovery was not known. Use of penicillin did not begin until the 1940s when Howard Florey and Ernst Chain isolated the active ingredient and developed a powdery form of the medicine.

History of Penicillin

Originally noticed by a French medical student, Ernest Duchesne, in 1896. Penicillin was re-discovered by bacteriologist Alexander Fleming working at St. Mary's Hospital in London in 1928. He observed that a plate culture of Staphylococcus had been contaminated by a blue-green mold and that colonies of bacteria adjacent to the mold were being dissolved. Curious, Alexander Fleming grew the mold in a pure culture and found that it produced a substance that killed a number of disease-causing bacteria. Naming the substance penicillin, Dr. Fleming in 1929 published the results of his investigations, noting that his discovery might have therapeutic value if it could be produced in quantity.

Dorothy Crowfoot Hodgkin

Hodgkin used x-rays to find the structural layouts of atoms and the overall molecular shape of over 100 molecules including penicillin. Dorothy's discovery of the molecular layout of penicillin helped lead scientists to develop other antibiotics.

Dr. Howard Florey

It was not until 1939 that Dr. Howard Florey, a future Nobel Laureate, and three colleagues at Oxford University began intensive research and were able to demonstrate penicillin's ability to kill infectious bacteria. As the war with Germany continued to drain industrial and government resources, the British scientists could not produce the quantities of penicillin needed for clinical trials on humans and turned to the United States for help. They were quickly referred to the Peoria Lab where scientists were already working on fermentation methods to increase the growth rate of fungal cultures. On July 9, 1941, Howard Florey and Norman Heatley, Oxford University Scientists came to the U.S. with a small but valuable package containing a small amount of penicillin to begin work.

Pumping air into deep vats containing corn steep liquor (a non-alcoholic by-product of the wet milling process) and the addition of other key ingredients was shown to produce faster growth and larger amounts of penicillin than the previous surface-growth method. Ironically, after a worldwide search, it was a strain of penicillin from a moldy cantaloupe in a Peoria market that was found and improved to produce the largest amount of penicillin when grown in the deep vat, submerged conditions.

Andrew J. Moyer

By November 26, 1941, Andrew J. Moyer, the lab's expert on the nutrition of molds, had succeeded, with the assistance of Dr. Heatley, in increasing the yields of penicillin 10 times. In 1943, the required clinical trials were performed and penicillin was shown to be the most effective antibacterial agent to date. Penicillin production was quickly scaled up and available in quantity to treat Allied soldiers wounded on D-Day. As production was increased, the price dropped from nearly priceless in 1940, to $20 per dose in July 1943, to $0.55 per dose by 1946.

As a result of their work, two members of the British group were awarded the Nobel Prize. Dr. Andrew J. Moyer from the Peoria Lab was inducted into the Inventors Hall of Fame and both the British and Peoria Laboratories were designated as International Historic Chemical Landmarks.

Andrew J Moyer Patent

On May 25, 1948, Andrew J Moyer was granted a patent for a method of the mass production of penicillin.

Resistance to Penicillin

Four years after drug companies began mass-producing penicillin in 1943, microbes began appearing that could resist it. The first bug to battle penicillin was Staphylococcus aureus. This bacterium is often a harmless passenger in the human body, but it can cause illness, such as pneumonia or toxic shock syndrome, when it overgrows or produces a toxin.

History of Antibiotics

(Gr. anti, "against"; bios, "life") An antibiotic is a chemical substance produced by one organism that is destructive to another. The word antibiotic came from the word antibiosis a term coined in 1889 by Louis Pasteur's pupil Paul Vuillemin which means a process by which life could be used to destroy life.

Ancient History

The ancient Egyptians, the Chinese, and Indians of central America all used molds to treat infected wounds. However, they did not understand the connection of the antibacterial properties of mold and the treatment of diseases.

Late 1800s

The search for antibiotics began in the late 1800s, with the growing acceptance of the germ theory of disease, a theory which linked bacteria and other microbes to the causation of a variety of ailments. As a result, scientists began to devote time to searching for drugs that would kill these disease-causing bacteria.


The surgeon Joseph Lister began researching the phenomenon that urine contaminated with mold would not allow the successful growth of bacteria.


German doctors, Rudolf Emmerich and Oscar Low were the first to make an effective medication that they called pyocyanase from microbes. It was the first antibiotic to be used in hospitals. However, the drug often did not work.


Sir Alexander Fleming observed that colonies of the bacterium Staphylococcus aureus could be destroyed by the mold Penicillium notatum, demonstrating antibacterial properties.


Prontosil, the first sulfa drug, was discovered in 1935 by German chemist Gerhard Domagk (1895–1964).


The manufacturing process for Penicillin G Procaine was invented by Howard Florey (1898–1968) and Ernst Chain (1906–1979). Penicillin could now be sold as a drug. Fleming, Florey, and Chain shared the 1945 Nobel Prize for medicine for their work on penicillin.


In 1943, American microbiologist Selman Waksman (1888–1973) made the drug streptomycin from soil bacteria, the first of a new class of drugs called aminoglycosides. Streptomycin could treat diseases like tuberculosis, however, the side effects were often too severe.


Tetracycline was patented by Lloyd Conover, which became the most prescribed broad spectrum antibiotic in the United States.


Nystatin was patented and used to cure many disfiguring and disabling fungal infections.


SmithKline Beecham patented Amoxicillin or amoxicillin/clavulanate potassium tablets, and first sold the antibiotic in 1998 under the tradenames of Amoxicillin, Amoxil, and Trimox. Amoxicillin is a semisynthetic antibiotic.