Penicillin Developments

The discovery of penicillin and the scope of its possible usage is arguably the most important scientific discovery of the 20th century. The globalization of penicillin in the years immediately after the Second World War was swift, visible and interesting, and made this important antimicrobial drug both a political and a medical resource.

Image Credit: Fahroni / Shutterstock
Image Credit: Fahroni / Shutterstock

Discovery of penicillin

In 1928, Alexander Fleming was studying the growth and characteristics of staphylococci, a type of round-shaped bacteria. In one of his uncovered Petri dishes, airborne spores from a bluish-greenish mold from a genus Penicillium settled in and formed a large colony, which then spread out in a circle and set about dissolving the staphylococci.

This unforeseen event prompted Fleming to investigate the mold that was so effective in attacking the bacteria. In that same year, he isolated and cultivated this fungus in a liquid medium, and found an active substance in the broth. Fleming named the contaminated fungus Penicillium rubrum (later correctly identified as Penicillium notatum), which was the reason for naming the active substance penicillin.

Image Credit: Kallayanee Naloka / Shutterstock
Image Credit: Kallayanee Naloka / Shutterstock

Fleming’s penicillin paper was published in 1929 in the British Journal of Experimental Pathology, and the discovery was largely ignored until scientists at Oxford University recognized its importance in the early 1940s. Howard Florey from the William Dunn School of Pathology, a Cambridge biochemist Norman Heatley and Edward Abraham conducted exploratory research on how penicillin could be used to treat infections.

The publication of the Oxford report on the isolation of various types of bacteria with penicillin coincided with the battles of the Second World War. The first recipient of the penicillin for treating purposes was a police officer, Albert Alexander, who developed a life-threatening infection with huge abscesses after he had scratched the side of his mouth.

Further development

At the Radcliff Infirmary, between February and June 1941, many rooms that have been emptied due to deficiency of research funds at the William Dunn School of Pathology were transformed into penicillin factories. Still, the produced amounts were low, so one of the tasks was to re-isolate penicillin from the urine of patients.

The following step was to get adequate funding from pharmaceutical companies in order to increase production. With the support of the Rockefeller Foundation, Florey and his colleague Norman Heatley traveled to the United States in the summer of 1941 to see whether there was any interest from the American pharmaceutical industry to produce penicillin on a large scale.

Their efforts were a success; penicillin production using fermentation began to increase dramatically by early 1944, while the production of the drug in the United States jumped from 21 billion units in 1943, to more than 6.8 trillion units by1945. By the early 1950s, the major pharmaceutical company, Pfizer, was the largest producer of natural penicillin in the world.

Synthesizing penicillin

The effort to synthesize penicillin during the war was undoubtedly one of the most intensive undertakings in the history of inorganic chemistry. Although the natural fermentation process was satisfyingly used to produce penicillin, the production of synthetic penicillin was elusive.

After the war, chemist John Sheehan from the Massachusetts Institute of Technology pioneered synthetic penicillin in 1957 and first to use the term 'antibiotic'. His work opened the door for the creation of different, bacteria-specific penicillin drugs. Research still continues today in penicillin and related beta-lactam antibiotics.

Further Reading

Last Updated: Feb 25, 2023

Dr. Tomislav Meštrović

Written by

Dr. Tomislav Meštrović

Dr. Tomislav Meštrović is a medical doctor (MD) with a Ph.D. in biomedical and health sciences, specialist in the field of clinical microbiology, and an Assistant Professor at Croatia's youngest university - University North. In addition to his interest in clinical, research and lecturing activities, his immense passion for medical writing and scientific communication goes back to his student days. He enjoys contributing back to the community. In his spare time, Tomislav is a movie buff and an avid traveler.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Meštrović, Tomislav. (2023, February 25). Penicillin Developments. News-Medical. Retrieved on July 19, 2024 from

  • MLA

    Meštrović, Tomislav. "Penicillin Developments". News-Medical. 19 July 2024. <>.

  • Chicago

    Meštrović, Tomislav. "Penicillin Developments". News-Medical. (accessed July 19, 2024).

  • Harvard

    Meštrović, Tomislav. 2023. Penicillin Developments. News-Medical, viewed 19 July 2024,


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Alarming rise in antibiotic-resistant urogenital infections in Greece, study shows escalating resistance trends