Some microbiologists become famous by indentifying and naming microbes. For example Daniel Salmon named Salmonella and Theodor Escherich named a common intestinal microbe. Can you name it? Escherichia coli commonly called E.coli.

In the 1600s, Robert Hooke and Antony van Leeuwenoek observed matter with the microscope. Included in their observations were bacteria and protozoans.

Earlier in our discussion of microbiology we mentioned that Whittaker, Woese, and Fox have made important contributions related to the grouping of microbes and naming major kingdoms of living organisms.

Microbes are very numerous in the soil and microbiologists including Winogradsky provided important research and information related to decomposition by soil microbes.

Robert Koch is one of the most well-known microbiologists. Today it is common sense to believe that individual infections are caused by individual microbes. In the late 1800s Robert Koch realized that he must prove the germ theory of disease. By studying anthrax in 1876 and tuberculosis in 1882, he established a series of principles or postulates to direct research and investigations. Koch's postulates state (1) evidence of a microbe must be found in a sick organisms; (2) microbe must be isolated and culture or grown in the laboratory; (3) healthy organism should be inoculated with microbe and show symptoms of disease found in the originally sick organism; and (4) the same microbe can be isolated from this second sick organism. Most infectious disease have been linked to know microbes; and new diseases like lyme diseas and hantavirus disease require application of Koch's postulates. Human subjects are often used to test drugs, vaccines, and even the germ theory itself. Important cases involving humans as subjects include using research scientists to prove causative microbes related to yellow fever, oroya fever, and even AIDS.