Dash of history...
At the beginning, microorganisms multiplication methods used broths based on fresh beef serum or meat extracts, which brought about numerous difficulties in obtaining pure cultures. In 1872 a German botanist, Joseph Schröter, managed to isolate bacteria on solid medium. In order to demonstrate separate colonies, he passaged dye-producing bacteria on cooked potato slices, coagulated egg white or starch.1
In 1881, during scientific conference in London, a German physician, Robert Koch presented new microbiological culture technique. That „innovation” consisted in enrichment of broth with gelatin, familiar by that time to mycologists, and pouring it onto flat glass plates. Though, so called, „nutrient gelatin” was a great move, it still was far from perfect. Gelatin-fixed media became liquid at temperature any higher than room one, which caused difficulties in or prevented growth of most pathogens. A year later Walther Hesse during his scientific leave spent in Kochs lab, replaced gelatin with agar. Actually, it was the idea of his wife Fannie, who eagerly participated in husband’s research. She had been using agar to gel her home made fruit jellies. The family recipe came from their Dutch friends, who had acquainted with culinary use of agar on Jawa.2 Unlike gelatin, agar does not melt at 37˚C, and rarely is digested by bacteria. Fannie was also artistic. Her drawings of microscopic preparations of bacteria and exquisite watercolours depicting various stages of growth of Salmonalla typhi colonies, published in her husbands’ papers, illustrated his research. Six years later, Julius Petri, another worker in Koch’s laboratory, modified the dishes for media – to keep contaminants out he designed an overhanging lid instead of the hitherto used cumbersome bell jars. That’s how the Petri dish arised.3
This amended technique of culture influenced development of new recipes for media. There are over 2.5 thousand of them in the Max Levin and Henri Schoenlein monography published in 1930!4
Until, more or less, ninety-thirties, in England media had been prepared by each laboratory for its own use. The growth of the London County Council hospital service which had resulted in development of, what we would call nowadays, a network of laboratories, had inspired British bacteriologist, James McCartney to set up a central media kitchen.5 Dr. MacCartney also introduced the screw-capped bottles for containing ready media.6 It was not before the end of the Second World War, however, that dehydratated culture media in the form we are familiar with, came into use.
Literature:
1. Hitchens, A. P. & Leikind, M. C. The Introduction of Agar-agar into Bacteriology. J Bacteriol, 37(5), 485-493 (1939).
2. Hesse, W. Walther & Angelina Hesse-Early Contributors to Bacteriology. ASM News 58, 425-428 (1992).
3. Petri, R. J. Eine kleine Modification des Koch’schen Plattenverfahrens. Centralbl. F. Bakteriol., 1, 279-280 (1887).
4. Levine, M. and Schoenlein, H. W. A compilation of culture media for the cultivation of microorganisms. Baltimore, The Williams & Wilkins Company, Baltimore USA (1930)
5. Collard, P. The development of microbiology. Cambridge University Press: New York (1976).
6. McCartney, J. E., 1933, Screw-capped bottles in the preparation and storage of culture media. Lancet, 2, 433 (1993).
