Microbiology, considered a specialized science, does not appear until the late nineteenth century. Following the classic scheme Collard (1976), we can distinguish four stages or periods in the development of Microbiology:
1. First period eminently speculative, extending from antiquity until the early microscopists.
2. Second period of slow accumulation of observations (from 1675 approximately half of the nineteenth century), which begins with the discovery of microorganisms by Leeuwenhoek (1675).
3. Third period, cultivation of microorganisms, up to the end of the nineteenth century, where figures of Pasteur and Koch achieving crystallize leading to Microbiology as well established experimental science.
4. Fourth period (from the early twentieth century to the present day), in which the microorganisms are studied in all its complexity physiological, biochemical, genetic, ecological, etc., and that is an extraordinary growth of Microbiology, the rise microbiological specialized disciplines (virology, immunology, etc), and the close interweaving of the microbiological sciences in the general framework of Biological Sciences.
In microbiology two theories were raised:
1. Spontaneous Generation: Theory Proponents of spontaneous generation arose that life could emerge from inanimate things. Aristotle, Needham, Pouchet and others.
2. The theory of biogenesis is the conception which posits that life arises from life Proponents: Francisco Redi, Espallanzan, Schlzey, Schwam, Scroder, Dush and Pasteur.
Louis Pasteur, in 1864, demonstrated the impossibility of spontaneous generation of life. And he accepted that it could not form complex living organisms such as insects, from nowhere, but still was not clear in the case of microorganisms. With their experiments they showed that air are microorganisms that decompose organic matter, concluding that every living being from another living being.
This refutation of spontaneous generation was a major milestone for science.
Lous Pasteur, father of Microbiology