Law of Biogenesis
(1876 +) (jan 1, 1876 – jan 1, 3000)
Description:
"Living things arise from other living things"
Louis Pasteur (1861) - French chemist "Father of Microbiology"
- First experiment: filtered air through a cotton plug used on a broth container. Examined broth via microscope, matched other broths seen in other experiments
- Dropped plug into sterile broth = cloudy w/ growth of bacteria
- Second experiment: Used swan-necked flasks, remained sterile even when left open
- Microorganisms from air settled @ bends of flask necks
John Tyndall (1876) - English Physicist
- Various types of broths require different boiling times to be sterilized? Why?
- Dust particles must have transferred heat-resistant microbes
- Microorganisms exist in 2 forms: heat-resistant & heat-sensitive
Ferdinand Cohn (1876) - German Botanist
- Endospores - heat resistant forms of some bacteria
- Found in soil, transported to broth via the hay used to make it, can lay dormant for years until environment becomes favorable
- Chemical stimuli from the environment cause the change from dormant to active
- Dormant = protective shell - Germanized = vulnerable
Added to timeline:
MicroBio Timeline 1
History of the Microscope
Immunizations
Date:
