This document summarizes the history of microbiology from its origins in the 17th century to modern times. Key events include Antony van Leeuwenhoek inventing the first microscope in the 1660s, Francesco Redi disproving spontaneous generation through experiments in the 1660s, Louis Pasteur demonstrating that microorganisms cause food spoilage and disproving spontaneous generation using swan-necked flasks in the 1860s, and Robert Koch establishing the germ theory of disease in the late 1800s. The field of microbiology arose from these discoveries and gave rise to molecular biology and biotechnology in the 20th century.

1. History
Of
Microbiology

2. By:-
V!jay Bar!a
vijaybaria007@yahoo.com

3. What is Microbiology?
•The science of microorganisms (very
small, unicellular organisms)
•The discipline is just over a century old
•Has given rise to molecular biology
and biotechnology

4.  3 historical discoveries
•Invention of the microscope
•Disproving spontaneous generation
•Demonstrating microorganisms cause
disease

5. Antony van Leeuwenhoek (1632-1723)
• Inventor of the first microscope

6. • Leeuwenhoek earned his living as a draper, but spent much of
his spare time constructing simple microscopes composed of
double convex glass lenses held between two silver plates (figure
below)
• his microscope could magnify around 50 to 300 times,

7. SPONTANEOUS GENERATION
•Redi demonstrated that organisms did not arise from
nonliving material.
•FRANCESCO REDI devised a set of experiments to
demonstrate that if pieces of meat were covered with
gauze so that flies could not reach them, no “worms”
appeared in the meat, no matter how rotten it was.
However, no maggots were observed in sealed piece of
meat (figure below)

8. • Despite the proof that maggots did not arise spontaneously,
some scientist still believed in spontaneous generation.

9. • Pasteur demonstrated that microorganisms in
the air were responsible for food spoilage
Constructed a swan-necked flask

10. • Pasteur’s experiment for the competition involved his famous
“swannecked” flasks

11. He boiled infusion in flask, heated the glass necks, and drew
them out into long, curved tubes open at the end. Air could enter
the flask without being subjected to any of the treatments that
critics had claimed destroyed its effectiveness.
Airborne microorganisms could also enter the necks of the flask,
but they became trapped in the curves of the neck and never
reached the infusions. The infusions from Pasteur's experiment
remained sterile unless a flask was tipped so that the infusion
flowed into the neck and then back into the flask.
This manipulation allowed microorganisms trapped in the neck
to wash into the infusion, where they could grow and cause the
infusion to become cloudy.

12. In another experiment Pasteur filtered air through three cotton
plugs. he then immersed the plugs in sterile
infusions, demonstrating that growth occurred in the infusions
from organisms trapped in the plugs.
 Pasteur, with his swan-necked flask, and Tyndall, with his dust-
free air, finally dispelled the idea of spontaneous generation.

13. Germ Theory of Disease
KOCH’S CONTRIBUTIONS
 Koch developed four postulates that aided in the definitive
establishment of the germ theory of disease. Koch’s Postulates
are follows:

18. • The cell was discovered by Robert Hooke in 1665. He
examined (under a coarse, compound microscope) very
thin slices of cork and saw a multitude of tiny pores that
he remarked looked like the walled compartments a
monk would live in. Because of this association, Hooke
called them cells, the name they still bear.
• Drawing of the structure
of cork by Robert Hooke that
appeared in Micrographic.