Intro to microbes and History of
Microbiology
III. What are Microbes (Microorganisms)
A. Living things seen only with magnification.
B. Examples
1. All Bacteria + All Viruses + All Protozoa
2. Some Fungi + Some Algae + Some Animals
Organisms included in the study of
Microbiology
1. Bacteria
2. Protozoans
3. Algae
4. Parasites
5. Yeasts and Molds
Bacteriology
Protozoology
Phycology
Parasitology
Mycology
– Fungi
6. Viruses
Virology
Bacteria - what comes to mind?
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Diseases
Infections
Epidemics
Food Spoilage
Only 1% of all known bacteria cause human
diseases
• About 4% of all known bacteria cause plant
diseases
• 95% of known bacteria are non-pathogens
Uses of Microbes
Benefit Humans
• 1.Bacteria are primary decomposers - recycle
nutrients back into the environment (sewage
treatment plants)
• 2. Microbes produce various food products
– cheese, pickles, sauerkraut, green olives
– yogurt, soy sauce, vinegar, bread
– Beer, Wine, Alcohol
3. Microbes are used to produce Antibiotics
• Mold
4. Bacteria synthesize chemicals that our body needs, but
cannot synthesize
• Example: E. coli
– B vitamins - for metabolism
– Vitamin K - blood clotting
• Escherichia coli
– Dr. Escherich
– Colon (intestine)
5. Biochemistry and Metabolism
• Very simple structure
• rapid rate of reproduction
• provides “instant” data
6. Microbial antagonism
• Our normal microbial flora prevents potential
pathogens from gaining access to our body
7. Insect Pest Control
• Using bacteria to control the growth of insects
• Bacillus thuringiensis
– caterpillars
– bollworms
– corn borers
8. Bioremediation
– Exxon Valdez - 1989
9. Recombinant DNA Technology, Gene Therapy,
Genetic Engineering
• Bacteria can be manipulated to produce enzymes
and proteins they normally would not produce
– Insulin
– Human Growth Hormone
– Interferon
10. Food Chains
• Marine and fresh water microorganisms
Microbes do benefit us, but they are
also capable of causing many diseases
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Pneumonia
Botulism
Cholera
Syphilis
Chlamydia
Meningitis
Strep Throat
Black Plague
Whooping Cough
Typhoid Fever
Scarlet Fever
Gonorrhea
Tuberculosis
Tetanus
Lyme Disease
Diarrhea
Measles
Mumps
Herpes 1
Herpes 2
RMSV
AIDS
Gangrene
IV. Pros and Cons of Microbes
A. Cons = Some spoil food – some pathogenic
(cause disease or infection).
B. Pros = Decomposemedicines-digestionbioremediation-Food/Alcohol.
A. 1590 – Janssen – makes first Compound
Microscope.
B. 1660 – Hooke – uses 1st compound microscope
to see Cork Cells.
• C. 1676 – Leeuwenhoek – see living cells with
simple scope.
– First to see microbes
D. 1798 Edward Jenner
• successfully vaccinated a boy against smallpox
in
• milkmaids exposed to cowpox never
developed the serious smallpox
• hypothesized that exposure to cowpox led to
protection against smallpox
• he inoculated James Phipps first with cowpox
material, and later with smallpox- causing
material
• The boy did not get smallpox.
E. 1818-1865 Ignaz Semmelweis
No one connected germs w/ disease yet
• Puerperal fever “childbirth fever” caused 2530% mortality
• 2 Observations
– Medical Students working on cadavers moved from
the dissecting room to the maternity ward
– Midwives - Stayed only in maternity ward
• Ordered students to wash hands and medical
instruments in chlorinated lime
• Mortality
F. Cohn – Discovered heat – resistant bacterial
endospores.
• classified bacteria into 4 groups based on
shape
*Sterile = free of all life forms
G. 1867 – Lister – defines Aseptic – techniques
which reduce microbes in medical settings.
Aseptic - Sterile
H. 1857 – 1885 Pasteur
1. Biogenesis
2. Pasteurization
• Fermentation mediated by yeast, not air
• Pasteurization to prevent wine and beer spoilage
3. Anthrax vaccine
4. Develops vaccine for Rabies in 1885
• I. 1881-1884 – TB + Kochs Postulates
1st to prove that bacteria actually caused diseases
Koch’s Postulates
1. The same organisms must be found in all cases
of a given disease.
2. Organism can be isolated and grown in pure
culture.
3. The isolated organism must reproduce the same
disease when inoculated into another animal
4. The original organism must again be isolated
from the experimentally infected animal.
J. 1885 - Paul Ehrlich
• Chemotherapy-Treatment using chemical
substances
• Magic bullet”
–Salvarsan (arsenic derivative)
• Preparation 606
–Syphilis
K. 1890 Petri – Petri dish
a) Worked in Koch’s lab
L. 1892 Dmitri Ivanovski - Discovered viruses
M. 1929 Fleming – Discovered Penicillin
M. 1953 Watson & Crick – Discovered structure
of DNA.
N. 1954 Jonas Salk – Polio Vaccine
Golden Age of Microbiology
1857 - 1914
• Pasteur
– Pasteurization
– Fermentation
• Joseph Lister
– Phenol to treat surgical wounds – 1st attempt to control infections
caused by microoganisms
• Robert Koch
– Koch’s Postulates
• Edward Jenner
– vaccination
• Paul Erlich
– 1st synthetic drug used to treat infections
– Salvarsan - arsenic based chemical to treat Syphilis
• “salvation” from Syphilis
VII. Microbial Taxonomy
A. Refer to pages 284-291