The History of Medicine tells that, back in 1877, as an assistant to the great Robert Koch (known mainly for his work on tuberculosis, as well as for being the father of medical microbiology), an idea emerged in the mind of the German physician Julius Richard Petri. There must have been some way to facilitate the handling of microbial cultures and, out of that discomfort, the famous Petri dishes were born.
Specially designed for bacterial cultures, mould and other microorganisms, these dishes continue to be used in microbiology. Another technique developed at the same time and which, together with the Petri dishes, turns out to be a magnificent canvas for a certain type of art, continues to be used. Let’s see, around 1881 the doctor Walther Hesse, also a disciple of Koch, perfected a technique by which he could cultivate microorganisms in an appropriate and practical way, which until then was a real nightmare. After much rehearsal, it was his wife, Fanny Hesse, who gave birth to the idea of using an algae-derived extract known as agar-agar as a culture medium (she had used this material in jams for years). Agar-agar was shown to be ideal for gelling the culture medium, resulting in a material that remains solid at room temperature. It is a translucent medium in which bacteria grow at ease, making it easier to identify the colonies.
So we already have the above-mentioned canvas, a petri dish, and a medium for bacterial culture, agar-agar. From there, to create works of art, there is only one step. Fanny Hesse herself, who was an excellent painter, produced several works in which she immortalized some microbial cultures. Now, it’s not about painting what you see in a lab, it’s about painting with your own bacteria (or fungi) growing! In this way the microbial art was born, which consists of “painting” using as canvas petri dishes with cultures of different types of microorganisms, usually using agar-agar as a medium. Bacteria, fungi or yeasts can be used with their original colours, or fluorescent (under suitable light) or with various pigments. Once the microorganisms have grown according to the patterns drawn on the plate, the result is fixed with synthetic resin and, that’s it, we have a work of microbial art.
Interestingly, one of the most famous microbial “painters” was Alexander Fleming, discoverer of the antibiotic action of lysozyme and penicillin. In fact, Fleming had been an amateur painter for years, being a member of art groups and the like, so it is not surprising that he ended up creating art with microorganisms and petri dishes. Okay, the results were simple, but they have their charm and the technique is far from simple. It is necessary to select the appropriate microorganisms, their colors, trace the pattern by means of grooves in the agar-agar medium on the petri dish and then deposit each type of microorganism in the appropriate place, so that they grow following the pattern marked in a few controlled times. It has complications, no doubt. Today these curious works of art are housed in the Alexander Fleming Laboratory Museum at Imperial College Healthcare – NHs Trust.
Further información: Smithsonian – Painting With Penicillin: Alexander Fleming’s Germ Art.