1/20/12 Intro to Microbiolgy - the School of Biological Sciences

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Feb 20, 2013 (4 years and 3 months ago)

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1/20/12

Intro to Microbiology



Overview of microbiology and course


Microbes
-
small organisms


Bacteria, viruses, fungi


Microbiology exists as both basic and applied field


Basic
-
gains information on traits and properties of microorganisms


Applied
-
utilizes information from basic science



Medical microbiology



Bioremediation



Biotechnology


Microbiology versus Biology



Many similarities, just a change in scope and scale



Genetics, physiology, ecology, evolution, even behavior



Cells ar
e still key



Bacteria are prokaryotic cells and differ from eukaryotes



Fungi are eukaryotes



Viruses manipulate host cell machinery


Interactions with environment



Microbes reside in virtually all places on planet




Most live in subsurface of oceans

and land



Largest portion of biomass on the planet is microbial life



Approximately 10
30

microbial cells





Life on earth began as microbial life



No significant oxygen for first 2 billion years




Anaerobes





Chemisynthetic





Photosynthetic






Produced oxygen as waste




Microbes and humans



Infectious Disease




One of the strongest impacts on human history



Microbial flora




Help maintain homeostasis



Agriculture

Microbes form mutualistic relationships with legumes and fix
nitrogen


Comp
lex microbial community in cow rumen allows them to
digest cellulose based material.





Food and energy


Brewing and
levening


Fermentation


History
-



Hooke
-
described mold fruiting bodies with rudimentary microscope


Van Leeuwenhoek was first to
describe bacterial cells and their various
shapes


Cohn determined that some bacteria could form spores then germinate,
much like seeds. Also developed methods for sterilizing media.


Pasteur
-
dispelled notion of spontaneous generation and showed that
micro
bes in air called spoilage.


Also developed germ theory of disease


Developed vaccines against anthrax and rabies


Koch
-
developed rules by which pathogens could be identified:


Koch’s postulate



Pathogen had to be present in sick but not healthy individua
ls


Pathogen had to be isolated on media by researcher

Purified pathogen culture when introduced into healthy individual
would cause the same disease


Same pathogen must be reisolated from infected individuals.




Now we know that they only work with some
pathogens called
classical pathogens.


Understanding microbial diversity


We only know of approximately 10% of microbial species on planet



Most cannot be cultured alone but as part of a complex community


Winogradsky
-
discovered metabolically distinct
organisms in a column
of muddy water. Some bacteria don’t utilize organic material but
rather inorganic material to yield energy.


chemolithotrophy