History of Food Microbiology
Theory of Spontaneous Generation
Under this theory, food was spoiled because of 'spirits,. It is of course wrong. Louis Pasteur showed that this was incorrect. He showed that media exposed to air did not show growth. Only after direct contact was growth possible. Pasteur's experiment.
This works only with gram negative microorganisms. If microorganisms can form endospores, the spores will survive this treatment.
Robert Kock showed that disease is associated with microorganisms. He developed a theory that showed this association called Kock's Postulates. If a microorganism causes disease, the following will be true:
1. The disease causing microorganism should be isolated from the diseased plant or animal.
2. This isolate can be grown in the lab.
3. The microorganism cultured in the lab can be reintroduced to health plants or animals.
4. Healthy plants or animals will contract the disease and the causative microorganism can be isolated from the now diseased animal.
5. The isolated microorganisms can be grown in the lab.