> See also: > - [[Microbiology]] # History of Microbiology > - [[Origin of Life]] The earliest recorded observations of microorganisms included: - **Francesco Redi** *discredited spontaneous generation* through an experiment involving *decaying meat* in sealed, semi-sealed, and open containers. The lack of maggots growing in the sealed container provided evidence that *life could not sprout up* from nothing overnight (they actually came from fly eggs). - **Louis Pasteur** demonstrated that microorganisms carried out *fermentation* and recognized that *heat was effective at killing* these organisms. Developed the method of *pasteurization* to kill harmful bacteria and *better preserve food*. - Showed that pepper disease was caused by a protozoan. - **Robert Hooke** sliced cork viewed under microscope resembled rooms in a monestary (called “cells”) - **Anton van Leeuwenhoek** was the first person to observe microorganisms with a magnified glass ([[Microscopy|microscope]]) - **Robert Koch** - Koch’s Posulates: 1. The microorganism must be present in every case of the disease but absent from healthy organisms 2. The suspected microorganisms must be isolated and grown in a [[cell cultures|pure culture]] 3. The same disease must result when the isolated microorganism is inoculated into a healthy host 4. The same microorganisms must be isolated again from the diseased host - Problems - Pathogen may be virus not bacteria and can’t be cultured - Attenuation can cause pathogens to be less harmful it certain situations - Can be caused by multiple microorganisms - - **Carl Linnaeus** developed one of the earliest classification systems ([[taxonomy]]), specifically, the *binomial nomenclature* system. - **Joseph Lister** - **Ignatz Semmelweis** - hand washing/antiseptic techniques