Koch's Lab releases a method to pure culture microoganisms (1881)
Below is an article about the method and how it was developed. I do not know who the author was.
MICROBIAL SERENDIPITY: Until recently, few women have played a significant role in microbiology, however this young science owes the development of a crucial technique to a woman. Fanny Angelina Eilshemius was born in 1850 in New York of a wealthy Dutch immigrant family. As a young girl, Angelina toured Europe where she met a young German doctor, Walther Hesse, whom she married in 1874. Angelina Hesse settled down to being the wife of a busy country physician. W. Hesse, became interested in the new science of Microbiology and joined Koch's lab in 1881. Dr. Hesse studied many aspects of bacterial public health and bacterial metabolism . His wife, nicknamed Lina, assisted him, much like my wife does me, as a laboratory technician. She was a talented artist who drew illustrations for his publications. One hot summer when Walther was attempting to do counts on bacterial air contaminates he was having trouble with his GELATIN (what we call Jell-O) plates melting in the heat and being digested by many of the bacteria he tried to grow on them. In frustration, he asked his wife "Why do your jellies and puddings stay solid in the warm weather?". She explained to him that she used AGAR-AGAR, a complex polysaccharide extracted from seaweed, to keep them solid in hot weather. AGAR-AGAR had been used as a gelling agent in ASIA for centuries. She had learned of it as a youngster in New York from a Dutch neighbor who had immigrated from Java. Presumably Dr. & Mrs. Hesse discussed the possibility of using agar-agar to prepare microbial media and Dr. Hesse subsequently found that it worked beautifully. The following characteristics of AGAR-AGAR make it almost perfect for the growth of microbes on solid medium:
(a) non-toxic to most microbes.
(b) only melts at 100oC, but solidifies at about 45oC (a temperature most bacteria can survive).
(c) nontoxic to other forms of life.
(d) stable to sterilization temperatures.
(e) physiologically inert as very few bacteria have the #enzymes for digesting it.
This kitchen ingredient revolutionized the science of microbiology as it made what had been an arduous task of separating and growing microbes on solid surfaces a routine procedure. Dr. Hesse went on to make other important bacteriological discoveries and advances, such as bringing the pasteurization of milk to Germany; which prevented the death of children from TB- and milk contaminated with intestinal pathogens. Angelina died in 1934, when I was one year old, so you see how NEW the science of microbiology is? Ref.: ASM News 58:425 (1992).
Koch's Postulates (1884)
In his early work (published in 1876), Koch studied a disease of cattle called anthrax (which sometimes can occur in humans). Through careful study with a microscope Koch was able to determine that the blood of an anthrax infected animal was filled with the large spore-forming bacterium now called Bacillus anthracis. While he was able to determine that the infected blood had the bacterial cells present, he had yet to prove that the bacteria was the cause of the disease. Mere association of the bacterium with the disease did not prove that it actually caused the disease; it might instead be a result of the disease.
To determine if the bacterial cells were the cause of the disease, Koch took a small amount blood from a disease animal and injected it into a healthy animal. This animals became diseased and died, he took blood from this animal and injected into another animal to obtain the same results. He did this as often as 20 times. With this knowledge Koch went a step futher, he found that the bacteria could also be cultivated in nutrient fluids outside the animal body. Even after many transfers in culture the bacteria could still cause disease in an animal. So from this information he formed the following postulates:
1. The organism should be constantly present in animal/plant suffering from the disease and should not be present in healthy individuals.
2. The organism must be cultivated in pure culture away form the animal/plant body.
3. Such a culture, when inoculated into susceptible animals, should initiate the characteristic disease symptoms.
4. The organism should be reisolated from these experimental animals and cultured again in the laboratory, after which it should still be the same as the original organism.
