Contributions of renowned scientists in Microbiology

1. CONTRIBUTIONS OF RENOWNED
SCIENTISTS IN MICROBIOLOGY
Ms Saajida Sultaana Mahusook

2. ANTON VON LEEUWENHOEK
“Father of Bacteriology”
He was the first to
observe bacteria and protozoa.
Leeuwenhoek made
microscopes consisting of a
single high-quality lens of very
short focal length.
In 1674 he observed protozoa
and bacteria and named them
as “animalcules”, he was able
to isolate from different
sources, such as rainwater,
pond and well water, and the
human mouth and intestine.

4. ROBERT KOCH
Founder of Modern Bacteriology

5. Koch continued to improve his methods and techniques. By solidifying liquids such
as broth with gelatine and agar, for instance, he created a solid medium for growing
bacteria which was easier to handle than the liquids used by Pasteur. Koch's
assistant Julius Richard Petri (1852-1921) developed the Petri dish, which made
the observation of bacteria even easier.

6. Isolated Mucobacterium
tuberculosis responsible
for tuberculosis (1882)
Isolated
Vibrio
cholerae
responsible
for cholera
(1883).
Isolated
Bacillus
anthracis
responsible
for anthrax
(1876).
Koch and his team also developed
ways of staining bacteria to improve
the bacteria’s visibility under
the microscope, and were able to
identify the bacterial causes
of tuberculosis, anthrax and cholera.

7. Koch’s
Postulates

8. Louis Pasteur
“Father of Microbiology”

9. Disproved the theory of Spontaneous Generation

10. Pasteurization of milk, beer and wine. Fermentation by microorganisms

11. Pasteur effect
Studies with fermentation led Pasteur to the unexpected
discovery that the fermentation process could be arrested
by passing air (oxygen) through the fermenting fluid, a
process.
He concluded that this was due to the presence of a life-
form that could function only in the absence of oxygen. He
introduced the terms aerobic and anaerobic to designate
organisms that live in the presence or absence of oxygen,
respectively. He further proposed that the phenomena
occurring during putrefaction were due to specific germs
that function under anaerobic conditions.

12. Pebrine disease of silkworm brought a huge devastation to the
silkworm nurseries. His research succeeded in saving
the silk industry through a method that enabled the preservation
of healthy silkworm eggs and prevented their contamination by
the disease-causing organisms.
Germ theory of disease
states that certain diseases are caused
by the invasion of the body by
microorganisms, organisms too small to
be seen except through a microscope.

13. Developed vaccines against anthrax and rabies

14. Edward Jenner

15. Discovered of vaccination for smallpox. In 1796
Jenner found a young dairymaid, Sarah Nelmes,
who had fresh cowpox lesions on her hand. Using
matter from Sarah’s lesions, he inoculated an
eight-year-old boy, James Phipps, who had never
had smallpox. Phipps became slightly ill over the
course of the next 9 days but was well on the 10th.
On July 1 Jenner inoculated the boy again, this
time with smallpox matter. No disease developed;
protection was complete. In 1798 Jenner, having
added further cases, published privately a slender
book entitled An Inquiry into the Causes and
Effects of the Variolae Vaccinae.

16. ROBERT HOOKE

17. He observed the microscopic honeycomb
cavities in cork. Coined the term ‘’cell’’ and
published his findings in Micrographia

18. Francesco Redi

19. Francesco Redi's spontaneous generation experiment using jars of meat.
In the first jar, with the meat sealed inside by a stopper, maggots did not
appear on the meat;
in the second jar, covered with mesh, maggots also did not appear on the
meat;
but in the third jar, without a cover, maggots did appear on the meat and
developed into flies.

20. John Needham
Needham's experiment on spontaneous generation :
A. Needham heated the broth, let it sit uncovered for several days, then
observed microorganisms in the fluid.
B. Needham heated the broth, let it sit covered for several days, then
observed microorganisms in the fluid which may be because the cork
and flask were not sterile.
A
B

21. He boiled broth in two bottles, left one bottle open and one closed,
He found that new microorganisms appeared only in the open bottle.
His conclusion: the microorganisms entered the bottle through the air; they
were not generated spontaneously in the broth.

22. Find the Scientist and his contribution !

23. Reference:
• www.britannica.com
• https://www.visionlearning.com/en/library/Biology/2/Origin
s-of-Life-I/226
• https://www.philpoteducation.com/mod/book/view.php?id=
779&chapterid=1034#/
• www.google.com(images)
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