The history and scope of microbiology

1. History and Scope of Microbiology
DR. Harinatha Reddy,
Aswartha
BSc: I BCZ: 09/06/2017

2. History
 Anton van Leeuwenhoek (1632 - 1723) was a Dutch
tradesman and scientist, he is commonly known as "the
Father of Microbiology", and often considered to be the
first microscopist and microbiologist.
 Anton van Leeuwenhoek was the first person to observe
and describe single celled organisms, which he referred
to as animalcules (we now refer to as microorganisms).
He was also the first to record and observe muscle
fibres, bacteria, and blood flow in capillaries.
 Leeuwenhoek dealer in men’s clothing, but spent much
of his spare time constructing simple microscopes . His
microscopes could magnify around 50 to 300 times
 Beginning in 1673 Leeuwenhoek sent detailed letters
describing his discoveries to the Royal Society of
London. It is clear from his descriptions that he saw both
bacteria and protozoa.

3. Louis Pasteur
• Louis Pasteur (December 27, 1822 – September
28, 1895) was a French biologist, microbiologist
and chemist and discover the principles of
vaccination, microbial fermentation and
pasteurization.
• He was invited a technique of treating milk and
wine to stop bacterial contamination, a process
now called pasteurization.
• He discovered vaccination for Anthrax, Rabies,
Chicken cholera.
• Pasteur performed several experiments to
disprove spontaneous generation.

4. • Louis Pasteur
– demonstrated that alcoholic fermentations were the
result of microbial activity,
– that some organisms could decrease alcohol yield
and sour the product, and
– that some fermentations were aerobic and some
anaerobic;
– he also developed the process of pasteurization to
preserve wine during storage

5. Robert Koch
• Robert Koch (December 1843 – 27 May 1910) was German
physician and microbiologist. As the founder of modern
bacteriology and father of Microbial techniques.
• He is known for his role in identifying the specific causative
agents of tuberculosis, cholera, and anthrax and for giving
experimental support for the concept of infectious disease.
• In addition to his innovative studies on these diseases, Koch
created and improved laboratory technologies and techniques in
the field of microbiology.
• He proposed series of four generalized principles called Koch’s
postulates, linking specific microorganisms to specific diseases
that remain today the "gold standard" in medical microbiology.
• As a result of his ground breaking research on tuberculosis,
Koch received the Nobel Prize in Medicine in 1905.

6. There are four conditions which are now universally accepted
and popularly known as Koch’s postulates are:
1. The microorganism must be present in every case of the disease but
absent from healthy organisms.
2. The suspected microorganism must be isolated and grown in a pure
culture and its growth character be recorded.
3. The same disease must result when the isolated microorganism is
inoculated into a healthy host.
4. The same microorganism must be isolated again from the diseased host.
Koch’s proof that Bacillus anthracis caused anthrax . They discovered that
after buried of dead animals, anthrax spores survived and were brought to the
surface by earthworms. When healthy animals then ingested the spores and
they became ill.

7. The Development of Techniques
for Studying Microbial Pathogens
• Koch’s studies on bacterial diseases, it became necessary to isolate
suspected bacterial pathogens.
• Then he tried to solidify regular liquid media by adding gelatin. Separate
bacterial colonies developed after the surface had been streaked with a
bacterial sample.
• Despite its advantages gelatin was not an ideal solidifying agent because it
was digested by many bacteria and melted when the temperature rise
above 28°C.
• A better alternative was provided by Walther Hesse, one of Koch’s
assistants. he suggested the use of agar as a solidifying agent.
• Agar was not attacked by most bacteria and did not melt until reaching a
temperature of 100°C.
• One of Koch’s assistants, Richard Petri, developed the petri dish (plate), a
container for solid culture media. These developments made possible the
isolation of pure cultures that contained only one type of bacterium.

8. • Koch also developed media suitable for growing bacteria isolated from the body.
Because of their similarity to body fluids, meat extracts and protein digests were used
as nutrient sources.
• The result was the development of nutrient broth and nutrient agar, media that are still
in wide use today.
• Walter Hesse ( 1846-1911): Used Agar as a solidifying agent to harden media. Agar is
extracted from red algae.
• Agar is derived from the polysaccharide agarose, which forms the supporting structure
in the cell walls of certain species of algae, and which is released on boiling. These
algae are known as agarophytes and belong to the Rhodophyta (red algae).
• Rechard Petri ( 1852-1921): Used agar dish to provide a large area to grow.
• Christian Gram ( 1853-1935): Staining method that demonstrate bacteria and
distinguish between Gram positive and Gram negative bacteria.

9. Immunological Studies
• .
• Jenner is often called "the father of immunology", Edward Jenner, was an English
physician and discovered smallpox vaccine, the world's first vaccine
• The terms "vaccine" and "vaccination" are derived from Variolae vaccinae
(smallpox of the cow).
• Edward Jenner had used vaccination with material from cow pox lesions to protect
people against smallpox
• Studies on chicken cholera, Pasteur discovered that incubation of microorganism
cultures for long intervals result in attenuation of the bacteria, which results they
had lost their ability to cause the disease.
• If the chickens were injected with these attenuation cultures, they remained
healthy but developed the ability to resist the disease.
• He called the attenuation culture is a vaccine.
• Shortly after this, Pasteur and Chamberland developed an attenuated anthrax
vaccine in two ways: by treating cultures with potassium bichromate and by
incubating the bacteria at 42 to 43°C.

11. Paul Ehrlich
• Paul Ehrlich was a German physician and scientist who
worked in the fields of hematology, immunology, and
antimicrobial chemotherapy.
• His laboratory discovered Salvarsan, the first effective
medicinal treatment for syphilis, thereby initiating and also
naming the concept of chemotherapy.
• In the 1890’s Ehrlich proposed a theory of immunity in
which antibodies were responsible for immunity. In addition,
he is known as the father of modern chemotherapy. He also
develop a staining procedure to identify tubercle bacilli.

12. • In 1928 Fleming observed that the growth of the bacterium staphyloccus
aureus was inhibited in the areas surrounding the colony of a mold that
had contaminated a Petri plate. The mold was identified as Penicillium
notatum, and its active compound was named penicillin.
• Raymond Sabouraud ( 1890-1910): Develop culture media to study yeast
and molds.
• Dimitri Ivanovski (1892): Tobacco mosaic virus could pass through filters
used to remove bacteria.
• Selman Waksman (1940): Discovered a number of antibiotic such as
Tetracycline and Streptomycin.
• Phagocytosis was discovered by Élie Metchnikoff (1883). Phagocytosis is
the process by which a cell often a phagocyte a solid particle to form an
internal compartment known as a phagosome.
History of Microbiology: (13/06/2017)

13. JOHN TYNDALL (1820 – 1893)
In 1876 discovered that there were two different types of bacteria.
a)Heat sensitive or heat labile forms (vegetative cells) easily destroyed by boiling.
b) Heat resistant types known as an endospore.
• Tyndall demonstrated that alternate process of heating & cooling, if repeated five
times, can kill all the endospores. This is known as Sterilization process or
Tyndallization.
• Heat resistant forms which could not be killed by continuous boiling of the broth,
after boiling broth has cooled the endospore become vegetative cells in such
broth.
• If such broth further subjected to intermittent boiling or Discontinuous boiling
kills the heat resistant forms of bacteria and broth become completely free from
microorganisms and do not show any microbial growth.
• In the Tyndallization the medium exposing to 100 °C for 30 min for three days
with incubation at 37 °C temperature.
• The process also know as fractional sterilization.

14. Knoll and Ruska (1938) – First Electron Microscope
• The electron microscope is capable of magnifying biological specimens up
to one million times.
• To study detail structures of viruses and bacteria.
• These computer enhanced images of 1. smallpox, 2. herpes simplex, and 3.
mumps are magnified, respectively, 150,000, 100,000 and 90,000 times.
• WATSON and CRICK and FRANKLIN
• In 1953 Watson and Crick determined the structure of DNA. They used
their research, together with the research of Franklin to determine the
structure of the DNA molecule.

15. Scope and importance of microbiology:
• Industrial microbiology?
• Food microbiology?
• Milk and milk product microbiology?
• Water microbiology?
• Air microbiology?
• Genetic engineering?
• Microorganism in biodegradation?
• Biopesticides?

16. Industrial microbiology
• Industrial microbiology is a branch it uses microorganisms to
produce a desired product in mass quantities in order to make a
profit out of it.
• There are multiple ways to manipulate a microorganism in order to
increase maximum yield of product.
• Introduction of mutations into an organism many be accomplished
by introducing them to mutagens. Another way to increase
production is by gene amplification, this is done by the use of
plasmids, and vectors.
• The manipulation of organisms in order to yield a specific product
has many applications to the real world like the production of some
antibiotics, vitamins, enzymes, amino acids, solvents, alcohol and
daily products.
• They can also be used in an agricultural application and use them as
a biopesticede instead of using dangerous chemicals or as
inoculants and help plant proliferation.

17. Medical application:
• The medical application to industrial microbiology is the production of new
drugs synthesized in a specific organism for medical purposes.
• Production of antibiotics is necessary for the treatment of many bacterial
infections Some natural occurring antibiotics and precursors, are produced
through a process called fermentation.
• Penicillin production is an example of massively producing an antibiotic
using deep tank fermentation.
• Vitamins also get produced in massive quantities either by fermentation or
biotransformation. Vitamin B 2 (riboflavin) for example is produced both
ways. Biotransformation is mostly used for the production of riboflavin,
and the carbon source starting material for this reaction is glucose.
• Insulin synthesis is done through the fermentation process and the use of
recombinant E.coli or yeast in order to make human insulin also called
Humulin

18. • Dairy products like cheese and yogurt can also be made through
fermentation using microbes.
• Cheese was produced as a way to preserve the nutrients obtained from
milk, through fermentation thus elongating the shelf-life of the product.
• Microbes are used to convert the lactose sugars into lactic acid through
fermentation.
• The bacteria used for such fermentation are usually
from Lactococci, Lactobacilli, or Streptococci families.
Agriculture application:
• Biopesticide is a pesticide derivative from a living organism or natural
occurring substances. Microbial pesticides, usually a virus, bacterium, or
fungus are used to control pest populations in a more specific manner.
• The most commonly used microbe for the production of microbial bio-
pesticides is Bacillus thuringiensis, also known as Bt.
• This spore forming bacterium produces a delta-endotoxins in which it
causes the insect or pest to stop feeding on the crop or plant because the
endotoxin destroys the lining of the digestive system.

19. Water microbiology
• Water microbiology is concerned with the microorganisms
that live in water, or can be transported from one habitat to
another by water.
• Water can support the growth of many types of
microorganisms. The presence of other disease causing
microbes in water is unhealthy and even life threatening. For
example, bacteria that live in the intestinal tracts of humans
and other warm blooded animals, such as Escherichia coli,
Salmonella, Shigella, and Vibrio, can contaminate water if
feces enters the water.

20. Genetic engineering
• Genetic engineering, also called genetic modification, is the
direct manipulation of an organism's genome using
biotechnology.
• It is a set of technologies used to change the genetic
makeup of cells, including the transfer of genes within and
across species boundaries to produce improved or novel
organisms. New DNA is obtained by either isolating and
copying the genetic material of interest using molecular
cloning methods or by artificially synthesizing the DNA. A
construct is usually created and used to insert this DNA into
the host organism. As well as inserting genes, the process
can also be used to remove, or "knock out", genes. The new
DNA can be inserted randomly, or targeted to a specific
part of the genome.

21. Microbial bio degredation:
• Microbial bio degredation is the use of bioremediation and
biotransformation methods to harness the naturally occurring ability of
microbial xenobiotic metabolism to degrade, transform or accumulate
environmental pollutants, including hydrocarbons (e.g. oil), polyaromatic
hydrocarbons, heterocyclic compounds , pharmaceutical substances,
radionuclides and metals.
•

22. 1857 to 1914 is known as Golden Era
of Microbiology
Happenings
1.1 Discovery of agents of many diseases
1.2 Role of immunity in the prevention and cure diseases
1.3 Studies on chemical activities of Microorganisms
1.4 Improved techniques for performing microscopy and
culturing microorganisms
1.5 Developed vaccines and surgical techniques

23. • Louis Pasteur (December 27, 1822 – September 28, 1895)
was a French biologist, microbiologist and chemist and
discover the principles of vaccination, microbial
fermentation and pasteurization.
• The Germ theory of disease
• First proven by Robert Koch in 1876 ( The winner of 1905
Nobel prize in Medicine)
• Discovered Bacillus anthracis in blood of cattle that died
of anthrax - cultured the Bacteria.

24. THANK YOU