Download doc MIMM 211 Lecture Notes 2

MIMM 211 Lecture 2
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Spontaneous Generation (Abiogenesis)
Important Names
-John Needham
-Lazzaro Spallanzani
1859. French Academy of Science sponsored competition to disprove Spontaneous Generation
1861. Louis Pasteur - boiled meat broth in curved swan flask
a.
No micro-org. Developed
b.
Disproved spontaneous gen.
1877. John Tyndall proved that dust carried micro-org.
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Role of Micro-organisms in Disease
-Lucretius and Fracastro suggested invisible organisms cause diseases
-People believed diseases caused by
-Supernatural occurrences
-Imbalance in good/bad blood
-Bassi showed fungus caused disease in silkworms
-"Germ theory of disease" was born
-M.J. Berkeley showed that Irish Potato Blight was caused by fungus
-Pasteur showed that protozoans caused another disease in silkworms
-France then began producing silkworms from healthy moths.
1867. Joseph Lister- heat sterilized instruments and dipped surgical dressing in phenol
-he was interested in Pasteur's work
1876. ROBERT KOCH- discovered anthrax causing bacteria
-Koch's Postulates:
1. See lecture slides/wiki, anywhere, etc.
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Development of Techniques to Study Microorganisms
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Koch wanted to isolate suspected pathogens
o
Difficult to work with liquid culture (mixed bacteria is a problem)
o
Tried to grow bac. On solid surface
Easier to attain pure culture as a colony progenated from one bacterium will be
visible
o
Tried potato slice = failed
o
Tried solidified liquid media (gelatin + meat broth) = semi-fail
µ-organism degraded gelatin
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Gelatin melted at 37°C
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Fannie Eilshemius Hesse (wife of one of Koch's assistants)
o
Suggested using agar (from seaweed)
Richard Petri- (another one of Koch's assistants)- invented Petri Dish
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Koch eventually used meat extracts + protein with agar for media
o
Using the above techniques, he eventually isolated tuberculosis bac. et autres
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Beginning of IMMUNOLOGICAL STUDIES
-Ed Jenners immunized people against smallpox
-used fluid from cowpox blisters
-HYPOTHESIS: Dairy maids were immune to smallpox
-It worked
-Louis Pasteur created the first attenuated vaccine (1880s)
-grew pure culture (anthrax)
-attenuate them: incubate at 43-44° C and add Potassium bichromate
-provided immunity
-Did same with cholera, etc.
-D.E. Salmon + Theobalt Smith discovered that killed microbes also worked as vaccines
-von Bhring discovered humoral immunity antibodies could be produced in blood
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Rabies Vaccine and the Pasteur Institute of Paris
o
Rabies vaccine: attenuated culture of an abnormal growth
Brains + spinal cords from dead rabbits --> dried.
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o
Joseph Meister (a kid with rabies) received 13 injections of increased dosages of virus
over 10 days
Boy survived
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o
Pasteur became famous
People donated money to create the Pasteur Institute
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Industrial Microbiology and Microbial Ecology
-Pasteur discovered that microorgansims caused fermentation (sugar instability)
-from beet sugar to alcohol
-Eventually yeast was replaced by lactic acid
-Winogradsky- found that oxidation of iron, sulphur and ammonia of bacteria provided energy
-Begerinick- found nitrogen-fixing and sulfur-reducing bacteria
-W+B produced enrichment media (for soil?)
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Classifying Organisms
-Taxonomy- artificial classification of organisms
-Soley based on visible similarities
-Still used to name organisms
-Phylogeny- Natural classification of organisms
-Reflect evolutionaryrelations
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Phylogeny
-Before evolution concept, organisms were grouped by morphological similarities
-Many fossils were grouped by visible similarities
-Microorganisms were not classified until 1960s
-Used DNA
-Classified by using universal ubiquitous gene sequence to classify