Van Leeuwenhoek was the first to observe microorganisms using self-made microscopes in the 1670s. Throughout the 17th-18th centuries, scientists debated whether microorganisms arose spontaneously or from other organisms. Redi provided evidence against spontaneous generation by showing that flies lay eggs on meat. Spallanzani strengthened this by showing microbes did not grow in sterilized broth. Pasteur disproved spontaneous generation through experiments isolating microbes from air. Koch and others established the germ theory of disease in the late 1800s, showing specific microbes cause specific illnesses. Jenner developed the smallpox vaccine in 1796, providing the first example of disease prevention through inoculation

1. HISTORY OF MICROBIOLOGY
SHAHASAD SALAM
History of microbiology

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

7. Redi’s Experiment
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

10. Louis Pasteur
History of microbiology

11. 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

15. Koch's postulates
History of microbiology

16. Edward Jenner
 British
physician
 His experiment to find a way to protect people
from smallpox.
History of microbiology