2. INTRODUCTION
Microbiology is the Science that studies
Microorganisms.
Microorganisms, roughly, are those living things
that are too small to be seen with the naked eye.
Microorganisms cannot be distinguished
Phylogenetically from “Microorganisms.
For example, many fungi are microorganisms, as
well as all bacteria, all viruses, and most protists.
History of microbiology
3. Microorganisms only with major diseases such
as AIDS, uncomfortable infections, or such
.
common inconveniences as spoiled food.
Microorganisms also have many commercial
applications. They are used in the synthesis of
such chemical products as vitamins, organic
acids, enzymes, alcohols and many drugs.
Marine and freshwater microorganisms form
the basis of the food chain in oceans, lakes,
and rivers
History of microbiology
4. Antonie Van Leeuwenhoek (1632-1723)
He is the father microbiology.
Van Leeuwenhoek ground more than 500
optical lenses. He also created at least 25
microscopes.
Van Leeuwenhoek was introduced via
correspondence to the Royal Society of
London by the famous Dutch Physician Reinier
de Graaf. He soon began to send copies of his
recorded microscopic observations to the
Royal Society. In 1673 his earliest observations
were published by the Royal Society in its
journal: Philosophical Transactions.
History of microbiology
5. Spontaneous generation
Spontaneous generation theory that put forward by
the Aristotle.
Spontaneous generation is an obsolete principle
regarding " the origin of life from inanimate matter.
Living things came forth from nonliving things
because the nonliving material contained pneuma,
or "vital heat.
One school believed that the small organisms arose
from nonliving materials spontaneously known as
abiogenesis. Then others believed in biogenesis in
that living organisms arose from a living thing.
Animals do not arise by spontaneous generation.
History of microbiology
6. Francesco Redi, 1665.
He is an Italian physician.
He showed that maggots that develop on
putrefying meat are the larvae of flies.
Never appear if the meat is closed and the flies
are prevented from laying eggs.
For technical reasons, it is far more difficult to
prove that microorganisms do not arise
spontaneously One.
History of microbiology
8. John Needham(1713 – 1781)
He did experiments with gravy.
The experiments consisted of briefly boiling a broth
mixture and then cooling the mixture in an open
container to room temperature. Later, the flasks
would be sealed, and microbes would grow a few
days later. Those experiments seemed to show that
there was a life force that produced spontaneous
generation.
Needham did not use proper sterile technique. His
experiments were challenged and repeated by
Lazzaro Spallanzani, an Italian scientist.
History of microbiology
9. Lazzaro Spallanani
He is an italian scientist and he conducted a
number of experiments in the middle of the18th
century.
He repeated the exp of Needham.
On repeated boiling of gravy will kill the
endospore of any microbes.
Spallanzani did not have any microbes grow in
his sealed flasks
One of the first to provide strong evidence was
by him.
History of microbiology
12. John Tyndall(1820 –1893)
The proponents of spontaneous generation still kept up.
English physicist John Tyndall undertook a series of experiments.
If meat and vegetable infusions are heated for 5 min –sterile Hay
infusions – 5 min – not sterile.
Repeated the first set of experiments. Could not – even after1 hr. of
heating growth.
After many experiments realized that the hay had spores which
are resistant to heating.
The presence of hay in the lab caused the air to be laden with
spores.
Once he grasped this point, he proceeded to test the limit of heat
resistance of spores could not destroy even after heating 5-1/2
hrs.
Tyndall developed a method of discontinuous heating –Tyndalization – 1
min heating on five successive occasions sterilization.
Continuous boiling even for 1 hr. did not sterilize.
History of microbiology
13. The Germ Theory of Disease
The realization that yeasts playa crucial role in
fermentation was the first link be have been the
activity of a microorganism and physical and
chemical changes in organic materials.
This discovery alerted scientists to the possibility
that microorganisms might have similar
relationships with plants and animals specifically
that microorganisms might cause disease. This
idea was known as the Germ theory of disease.
History of microbiology
14. Robert Koch 1876
German physician.
He was Pasteur's young rival in the race to discover
the cause of anthrax, a disease that was destroying
cattle and sheep in Europe.
Koch discovered rod -shaped bacteria now known as
Bacillus anthracis (ba-sil'lus an-thra-'sis) in the blood
of cattle that had died of anthrax.
He cultured the bacteria on nutrient sand then
injected samples of the culture into healthy animals.]
When these animals became sick and died, Koch
isolated the bacteria in their blood and compared
them with the bacteria originally isolated .
He found that the two sets of blood cultures
contained the same bacteria.
History of microbiology