History and scope

1. HISTORY AND SCOPE OF
MICROBIOLOGY
Dr.D.Arvind Prasanth

2. History
•1665 Robert Hooke observed
living plant tissues (20X
mag.)
•“Little boxes” or Cells
•Used simple magnifying lens
•Suggested all living things
are made of cells

3. Hooke's Microscope
1665
Antonie van Leeuwenhoek
was inspired by this
publication

4. Antonie van Leeuwenhoek
(1677) (“layu-wen-hook”)
–First observation of living cells
(200-300X mag.)
–“Animalcules”
–Single lens Microscope (Self
made)—simple microscope
–Tooth plaque
–Rain water
–Diarrheal feces

5. Antonie van Leeuwenhoek
• Bacteria
• Protozoa
• Sperm cells
• Blood cells
• Microscopic
worms

6. Antonie van Leeuwenhoek’s
microscope
3-4” microscope
Required good
lighting and
patience

8. Spontaneous Generation
• The idea that life could arise
spontaneously from nonliving
matter
–Ex: Toads and Mice could arise
from soil
–Until the 18th century this
believe existed

9. History (cont.)
• 1668 Francesco
Redi
–1st one to
disprove
spontaneous
generation

10. Francesco Redi’s experiments
with meat
uncovered covered
Maggots No maggots
Disproved that maggots arise from decaying meat!!

11. • Proved (??) spontaneous generation
in chicken broth
• Heated Nutrient Fluids and poured
them into covered flasks
British clergyman John Needham’s
experiments (1745)
Hot Mutton
gravy
Turbid
broth
“...my phial swarm’d with life...”

12. Italian priest Lazzaro
Spallanzani (1765)
• Similar to Needham’s
Experiments
• He showed that heating a
sealed flask of meat broth
prevented growth of organism
• Skeptics claimed—lack of O2
prevented growth!!

13. The Golden Age of
Microbiology!
•Louis Pasteur (finally disproved
spontaneous generation after many years
of debate)
•Robert Koch (proof of germ theory)
•Other pioneers in Microbiology

14. Pasteur—Father of
microbiology
•1857- Louis Pasteur saves France’s wine
industry
•Napoleon III begged Pasteur (a chemist
by training) to help solve a problem
•Sailors were mutinying b/c their wine
was spoiling after only a few weeks at sea
•Pasteur armed with his trusty
microscope accepted the challenge

15. Louis Pasteur

16. –Spontaneous Generation finally
disproved
–Boiled broth in long-s-shaped necked
flasks (unsealed)
•Remained sterile
•Proved that microorganisms are
present in air, but air does not create
microbes
–Beginning of the golden age of
microbiology
Louis Pasteur (1861)

17. Swan neck flask experiment disproved spontaneous generation(1861)

18. History (cont.)
• 1861 Pasteur
–Proved Microorganisms are present in
nonliving matter
–Microbes can be destroyed by heat
•Aseptic Technique
• Fermentation mediated by yeast, not air
–Pasteurization to prevent wine and beer
spoilage (by bacteria)

19. 1857-Louis Pasteur saves
France’s wine
1)Good wine contained yeast
2)Sour wine contained bacterium (Bacteria
that use alcohol and produce acetic acid spoil wine by turning it to
vinegar (acetic acid).
3)He reasoned that if wine is heated to
destroy the harmful bacteria it
wouldn’t spoil (process known as

20. Pasteur’s Tomb in the Crypt of the Pasteur Institute in Paris

21. Germ Theory of Disease
• Pasteur proposed that wine
spoiling in an analogy for
disease (bacterial growth made the
wine “sick”)
• He hypothesized in 1857 that
microorganisms are responsible
for infectious diseases

22. Edward Jenner (country doctor)
–Milkmaid didn’t get smallpox b/c they
contracted the milder form of cowpox
–Immune system cannot distinguish btw
cowpox/smallpox
–Scratched a farmboy w/ a needle bearing
fluid from cowpox
–Small pox Vaccine
- -Vacca-cow
- Vaccination w/ cowpox provided
immunity for smallpox

24. Protection from a
disease from
vaccination
Immunity

25. Robert Koch (1843-1910)
• German country physician who developed
microbiology into a science
• Developed pure culture techniques (used
potato slices to grow bacteria) developed agar later on
• Proof of the germ theory
• Work with anthrax
• Koch’s postulates

26. Bacillus anthracis

27. Pure Culture Key to Studying
Microbes
Definition: Pure culture is a
population of organism, all of which
are the progeny of a single organism
-In nature, microbes almost never
occur as pure cultures

28. AGAR
•Is a complex polysaccharide derived from
seaweed
•Was suggested by Fannie Hesse wife of
Koch’s co-worker Walther Hesse
•“why do your jellies and pudding stay solid in warm weather”?
•AGAR-AGAR had been used as a gelling
agent in Asia for centuries
•Fannie learned to use AGAR-AGAR from a
Dutch neighbor in New York who spent time in
Asia

29. Koch’s postulates
1)Specific microorganism is present in all
cases of the disease
2)Organism can be obtained in pure
culture outside of the host
3)Organism when re-inoculated into host
causes the same symptoms
4)Organism can be isolated in pure culture
from experimentally infected host

30. Koch’s findings
Koch and his coworkers discovered that
bacteria caused
•TUBERCULOSIS
•CHOLERA
•DIPTHERIA
•TYPHOID FEVER
•GONORRHEA
•PNEUMONIA

31. Paul Ehrlich-hospital
dermatologist
• Chemotherapy-
Treatment using
chemical substances
• 1910 Paul Ehrlich
-”Magic bullet”
–Salvarsan (arsenic
derivative)
•Preparation 606
–Syphilis

32. Alexander Fleming –scottish
researcher--1928
• Discovered Penicillin (fungus) by
accident
• Was convinced that nasal mucus
had antibacterial effects
• Left his Staphylococcus culture on
an agar plate for 2 weeks-went on
vacation-came back &found mold
on his plate which prevented
bacterial growth (a mycology lab
underneath him had this rare spore drift)

35. Founders of Microbiology
(Review)
•First observed microbes—
Leeuwenhoek
•Proved living cells can arise only from
other living cells---Pasteur
•Confirmed the Germ Theory of Disease
--Koch

36. Scope of microbiology

37. Bacteria
•Medical importance
–Gastroenteritis
–Syphilis
–Tetanus
–Lyme disease
–Plague

38. Bacteria (cont.)
• Industrial importance
–Food supplements
•Amino acids & Vitamins
–Organic solvents
•Acetone

39. Bacteria (cont.)
• Pharmaceutical
importance
–Antibiotics
•polymyxin
–Hormones
•Insulin

40. Biotechnology and
Recombinant DNA
• Biotechnology:
–The use of microorganisms, cells, or
cell components to make a product
–Foods, antibiotics, vitamins, enzymes
• Recombinant DNA Technology:
–Insertion or modification of genes to
produce desired proteins

41. Bacteria (cont.)
• Environmental importance
–Biodegradation
•Oil spills
•Wastewater treatment

42. Gram positive
S. aureus

43. Gram negative
E. coli

44. Fungi
•Medical importance
–Valley fever
–Candidiasis
–Athlete's foot

45. Fungi (cont.)
• Industrial importance
–Fermentation
•Wine
•Beer
•Bread

46. Fungi (cont.)
•Pharmaceutical importance
–Antibiotics
•Penicillin

47. Fungi (cont.)
• Environmental importance
–Wastewater treatment
–Degradation of complex
organic matter
•Lignin in wood

48. Viruses
• Medical importance
–HIV
–Influenza
–Rabies
–Common cold