This is about history and scope related to microbiology .

1. B Y – P R I Y A N K A G U R U N G
HISTORY AND SCOPE OF
MICROBIOLOGY

2. HISTORY AND SCOPE OF
MICROBIOLOGY
 What is microbiology?
 Microbiology is the study of organisms and agents that are generally too small to be
seen clearly by the naked eye. These organisms include viruses, bacteria, algae,
fungi, and protozoa.
 Microbiology is linked to many other scientific disciplines following as -
 General microbiology: An overview of the diversity, structure, function, growth,
reproduction, genetics, physiology, preservation, and control of microorganisms
 Medical microbiology: Microbes that cause human disease
 Public health and epidemiology: Studies and controls transmission, frequency,
and distribution of disease.
 Immunology: Study of the immune system.
 Agricultural microbiology: Impact of microbes on agriculture.
 Microbial ecology: relationships between microbes and their habitats.
 Food microbiology: Prevention of food borne disease; microbes that make food
and drink.
 Industrial microbiology: Commercial use of microbes to produce products.
 Biotechnology: Manipulation of organisms to form useful products.

3. Landmarks in the History of Microbiology
 A. Discovering the "organisms"
 1. Antonie Leeuwenhoek (1676) – first to observe and describe
microbes accurately

4.  2. C. Chamberland (1884)– constructed a
bacterial filter that allowed the identification of
viruses

5.  3. Loeffler and Frosch (1898) – identified
filterable infectious agent as cause of foot-and-
mouth disease in cattle

6.  4. M. Beijerinck (1898-1900)– identified tobacco
mosaic virus

7.  5. S. Prusiner (1982)– described prions
(infectious protein that causes a particular normal
protein to alter its shape and become a prion)

8.  B. Disproving spontaneous generation (that living organisms
could develop from nonliving matter)
 1. F. Redi (1688)– first to challenge theory of spontaneous
generation by showing that if raw meat was protected from flies, the
formation of maggots was prevented.

9.  2. R. Needham (1748)– supported spontaneous
generation of microbes by showing that even after boiling
mutton broth and pouring into sealed containers, growth of
microbes occurred.

10.  3. L. Spallanzani (1776)- challenged spontaneous
generation as it pertained to microbes by showing that
sealed containers that were boiled do not produce microbes

11.  4. L. Pasteur (1861)– disproved spontaneous generation
 a) filtered air - showed that air contained microbial organisms
 b) constructed flasks with curved neck that allowed air into the flasks while
dust, etc. remained in the neck placed broth into the flasks and boiled showed
that no microbial growth resulted unless flasks were tipped to allow the broth
into the neck.

12.  C. The germ theory of disease
 1. Previously, people thought that disease was punishment for an individual's
crimes, due to poisonous vapors, and/or an imbalance of the "four humors".
 2. First proponents of the idea that invisible organisms caused disease were
Lucretius (B.C.) and Fracastoro (1546)
 3. A. Bassi (1835) showed that silkworm disease was due to a fungus.
 4. J. Lister (1867) showed that antiseptic surgical procedures reduced the
frequency of wound infections.
 5. R. Koch (1876-1884)definitively proved that Bacillus anthracis caused the
disease anthrax in cows and Mycobacterium tuberculosis caused the disease
tuberculosis using Koch's postulates.
 a) The suspected pathogen should be present in ALL cases of the disease and NOT
present in healthy animals.
 b) The suspected pathogen should be grown in vitro in pure culture.
 c) Cells from a pure culture of the putative pathogen should cause disease in healthy
animals.
 d) The putative pathogen should be reisolated from the infected animal.

14.  D. Preventing disease by vaccination
 1. E. Jenner inoculated people with cowpox to
protect against smallpox.

15.  2. Pasteur (1885) developed the rabies vaccine.
 3. von Behring and Kitasato (1890)produced
antibodies to purified toxins to protect against
diphtheria and tetanus.
Emil kitasto
Von
behring

16.  E. Metchnikoff (1884)described phagocytosis
of bacteria.

17.  E. Discovering the effect of microbes on
organic and inorganic matter
 1. Louis Pasteur (1856) described lactic acid
fermentation; contributions to wine industry.
2. S. Winogradsky and M. Beijerinck (1887-1900)
studied soil microbes and their role in the biochemical cycles
of sulfur, carbon, nitrogen.

18. Recent history of microbiology – the
20th century
 A. Infectious diseases: The etiological agent of most infectious diseases has been
ascertained. Current research focuses on understanding the molecular mechanisms by which
disease is caused.
 B. Chemotherapy: chemical that binds to and specifically kills microbes or tumor
cells. The term chemotherapy was coined in this regard by Paul Ehrlich.
 C. Physiology and biochemistry: Using microbes as a model, many physiological and
biochemical processes have been elucidated.
 D. Genetics: Many of the advances in molecular genetics were made using bacteria as models.
A few of the many -
 1. Beadle and Tatum (1941) – 1 gene = 1 enzyme
 2. Luria and Delbruck (1943) – mutations are spontaneous in nature
 3. Avery, MacLeod, and McCarty(1944) – DNA is the genetic material
 4. Jacob and Monod (1961) – the operon and gene regulation
 E. Molecular biology: Many of the advances in molecular biology were made using bacteria
as models. A few of the many:
 1. 1970: Restriction enzymes discovered
 2. 1979: Insulin synthesized using recombinant techniques
 3. 1990: Gene therapy trials begin
 4. 1995: The nucleotide sequence of the first free-living organism (Haemophilus
influenzea) published by Craig Venter and colleagues (1995).

19. SCOPE OF MICROBIOLOGY -
 1. Medical microbiology and immunology –
deals with disease producing organisms in human
beings whereas immunology deals with the defence
the body against various pathogens (disease causing
microorganisms) and factors which explain
resistance to disease.
 It furnishes the basic knowledge which depends on
practical methods employed for laboratory diagnosis
and preventation of microbial disease.

20.  2. Air microbiology – study variety of
microorganisms in the air such as air-borne
microorganisms give rise to serious problems via
contaminating the equipments, materials and spoils
food and food products and responsible for many
diseases in plants, animlas and humans.

21.  3. Water microbiology – water plays an
important role in living systems. When water
precipitates it picks up airborne microorganisms.
 When comes in contact with soil,other
microorganisms get into it from soil,organic
wastes,dead plants,dead animals,sewage etc
 Therefore, water must be free from microorganims
by filtration and chemical treatment to avoid them.

22.  4. Food microbiology – deals with relationship of
microorganisms to the manufacture, deterioration
and preservation of foods.
 To ensure food is free of harmful microorganism and
safe for human consumption.
 Some microorganism are of great use to humans
because of fermentation technology of various raw
materials by them result in food like breads , oriental
foods.

23.  5. Milk microbiology – deals with microorganism
present in and their role in milk and milk products.
 Milk becomes contaminated in handling and
processing i.e if it is not properly treated
microorganisms grow and spoil and make it unsafe
for human consumption.
 Some microorganism used in manufacture of milk
products such as cheese, butter .

24.  6. Soil microbiology –delas with microorganism
present in and their role in soil.
 Function of soil microorganism is to decompose
various organic matter and mineralization of organic
constituents i.e carbon, nitrogen, phosphorus,
sulphur via respective cyclic alterations by soil
microorganism make this available for reuse by
plants and other microorganisms.
 Improves soil fertility by fixing atmospheric nitrogen
into nitrogen compounds .

25.  7. Industrial microbiology – deals with utility of
microorganisms in industrial production of
medicine,food supplements, alcohol, beverages,
vitamins, enzymes, production of antibiotics.

26.  8. Genetic engineering – deals with manipulation
of genes under highly controllable laboratory
conditions.
 It is being applied in food and drug industries, waste
disposal, agriculture, oil pollution, medicine .

27. Thank you