History of Microbiology Flashcards
All cells have
Metabolism. growth. evolution.
What are the two types of metabolism?
genetic and catalytic.
only SOME cells have these properties
differentiation, genetic exchange, communication, motility.
The 2 main themes of microbiology
- understanding basic life processes
2. how they benefit humans.
How do cells act as machines? Coding devices?
Cells act as machines because they carry out chemical transformations. (Enzymes!!!)
Coding devices: they store/ process information, DNA/Evolution.
Populations of interacting assemblages are
microbial communities.
Habitat
The environment in which a microbial population lives is its
Ecosystem
refers to all living organisms plus physical and chemical constituents of their environment
Microbial ecology
is the study of microbes in their natural environments
Global estimate of microbes
5 x 10^30
Where are microbes mostly found
oceanic and terrestrial subsurfaces
1 billion y.o. earth was exclusive?
Microbial.
pH level of stomach, small and large intestine.
Stomach 2
Small 4-5
Large 7
Louis Pasteur
Discovered alcoholic fermentation as a biological and not chemical process.
- Disproved theory of spontaneous generation
- Led to developing a method to control growth
- Vaccines for anthrax, fowl cholera, rabies.
What did pasteurs experiment prove?
Proved there is NO spontaneous generation because the flask that tipped over, came into contact with dust and particles which contaminated the sterile liquid.
Robert Koch
- demonstrated the link between microbes and infectious disease. (anthrax/tuberculosis)
- Postulates demonstrated cause and effect
- developed solid media for pure cultures.
Name his postulates
- The suspected pathogen must be present in all cases of the disease and absent from healthy animals.
- the suspected pathogen must be grown in pure culture
- cells from a pure culture of suspected pathogen must cause disease in the healthy animal.
- The suspected pathogen must be reisolated and shown to be the same as the original.
Martinus Beijerinck
Developed Enrichment Culture Technique
-Microbes isolated from natural samples in a highly selective fashion by manipulating nutrient and incubation conditions e.g., Nitrogen-fixing bacteria (probably most important to humans); also sulfate reducers and S-oxidizers, Lactobacillus, green algae, some anaerobes, others
Sergei Winogradsky (1856-1953) and the Concept of?
Chemolithotrophy.
- Demonstrated that specific bacteria are linked to specific biogeochemical transformations (e.g., S & N cycles)
- Proposed concept of chemolithotrophy: Oxidation of inorganic compounds linked to energy conservation
Chemolithotroph
energy from oxidation of inorganic compounds (e donors)
chemoorganotroph
energy from oxidation of organic compounds
chemoautotrophs
chemoautotrophs feed themselves using inorganic energy sources such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia (most are extremophiles)
In 20th century microbiology developed in two distinct directions
Applied and Basic
? developed from concepts developed by Beijerinck and Winogradsky
Agricultural Microbiology and Industrial Microbiology
