History of Microbiology
VOCABULARY
Fermentation: the enzymatic
degeneration of carbohydrates in which
the final electron acceptor is an organic
molecule (contains carbon). For example,
ATP is synthesized by phosporylation
(adding phosphate) and oxygen it is not
required. Fermentation is the process that
yeasts use to convert sugars to alcohol in
the absence of air.
 Pasteurization: the process of mild
heating to kill particular spoilage
microorganisms or pathogens.
 Anaerobic: without oxygen

Aristotle
Spontaneous
Generation
Virgil
Bees grow
from honey
and flies
grow from
meat
The Romans
Used a
magnifying
lens called
“Flea glasses”
Zacharias Janssen
Invented
the first
compound
microscope
The First Microscope
Galileo
Improved the microscope,
Improved the telescope
First
Telescope
Antoni Van Leeuwenhoek
Improved
the simple
microscope to a
magnification of
270x
Described first
microbes.
Antoni Van Leeuwenhoek
Basic Shapes
COCCI
Staphylococci
Streptococci
RODS
SPIRALS
Arrangements
 Pairs:
diplococci,
diplobacilli
 Clusters:
staphylococci
 Chains:
streptococci,
streptobacilli
Robert Hooke
Coined the term
“cells”
Robert Hooke
The Debate Over Spontaneous
Generation
 The
hypothesis that living organisms
arise from nonliving matter is called
spontaneous generation. According to
spontaneous generation, a “vital force’
Forms life.
 The alternative hypothesis, that the
living organisms arise from preexisting
life, is called biogenesis.
Francisco Redi
Biogenesis
Theory:
Maggots do
not grow
from meat.
Francisco Redi
Evidence Pro and Con
 1668:
Francisco Redi filled six jars
with decaying meat.
Conditions
Results
3 jars covered with fine net
No maggots
3 open jars
Maggots appeared
From where did the maggots come?
What was the purpose of the sealed jars?
Spontaneous generation or biogenesis?
John Needham
Put boiled
nutrient broth
into covered
flasks.
 1745:
John Needham put boiled
nutrient broth into covered flasks.
Conditions
Results
Nutrient broth heated, then placed in
sealed flask
Microbial growth
From where did the microbes come?
Spontaneous generation or biogenesis?
 1861:
Louis Pasteur demonstrated that
microorganisms are present in the air.
Conditions
Results
Nutrient broth placed in flask, heated,
not sealed
Microbial growth
Nutrient broth placed in flask, heated,
then sealed
No microbial growth
Spontaneous generation or biogenesis?
Louis Pasteur
The Theory of Biogenesis
 Pasteur’s
S-shaped
flask kept
microbes
out but let
air in.
Figure 1.3
Edward Jenner
First
vaccine:
Smallpox
Edward Jenner
Rudolf Virchow
Cell Theory
1. All living things are
composed of cells.
2. Cells are the
smallest working
units of living things.
3. All cells come from
preexisting cells by
cell division
(biogenesis theory).
Agostino Bassi
Silkworm disease is
caused by a fungus
Louis Pasteur
Spontaneous Generation Theory





Aristotle thought that the mice grew from the
grain and hay, and he coined the term
“Spontaneous generation”
Virgil: bees grew from honey and that flies grew
from meat.
Redi: maggots in meat were caused by flies
laying eggs; they only grew on the meat in which
the jars were not covered.
John Needham believed in spontaneous
generation; boiled nutrient broth to kill all
microbes, put a non-sterile cork in the flask,
found that the broth grew microbes.
Louis Pasteur: made a glass flask with an “S”
shaped bend in it so that bacteria could not enter
into it but air could get in. He placed chicken
broth in the flask and boiled it so that it was
sterile and observed that there was no bacterial
growth in the broth.
Sheep Vaccine for Anthrax
Robert Koch
Koch’s Postulates
Obtain the disease causing microbe from
the sick animal via a sample.
 Isolate this microbe in pure culture.
 Inoculate a healthy animal with this pure
culture, and the healthy animal should
develop the same disease.
 Re-isolate the microbe from the second
animal. If it is the same microbe obtained
from the first animal, this proves the
etiology (cause) of the disease.

Joseph Lister
Operation using Lister's carbolic
spray invented in 1869
Ignaz Semmelwise
Puerperal fever could be
drastically cut by use of
hand washing standards in
obstetrical clinics.
Paul Ehrlich
First
Antibiotic:
For syphilis
Paul Ehrlich
Von Behring
Invented
diphtheria
antitoxin
Ross
Mosquitoes
transmit malaria
Metchnikoff
Discovered
White Blood
Cells and
phagocytosis:
Began field of
immunology
Alexander Fleming
The Birth of Modern
Chemotherapy
1928: Alexander
Fleming discovered
the first antibiotic.
 He observed that
Penicillium fungus
made an antibiotic,
penicillin, that killed
S. aureus.
 1940s: Penicillin was
tested clinically and
mass produced.

Figure 1.5
Chain and Florey
Purified
penicillin
as a
medicine
Rebecca Lancefield
Lancefield’s Streptococcus
Classification
Frederick Griffith
Discovered
DNA
Watson and Crick
Detailed the
structure of
human
DNA.
DNA Structure
Deoxyribose (sugar)
 A, T, C, G (nucleic acids)
 Phosphate (to form the
bonds)

Jacob and Monod
Role of
mRNA in
protein
synthesis
Protein Synthesis
Delbruck and Hershey
Structure
of viruses
Virus
Tonegawa
Antibody genetics
Prusiner
Discovery of
prions
Prions
SELECTED NOBEL PRIZES IN
PHYSIOLOGY
1901
 1902
 1905
 1908
 1945
 1969
 1987
 1997

Behring
Ross
Koch
Metchnikoff
Fleming, Chain, Florey
Delbruck, Hershey
Tohegawa
Prusiner
diphtheria antitoxin
malaria transmission
TB bacterium
phagocytosis
penicillin
viral replication
antibody genetics
prions