11. some forms of life could arise from āvital forcesā
nonliving or decomposing matter
organisms can arise form non-living matter.
Aristotle proposed
spontaneous generation
13. LOUIS JABLOT
a
heated container that was closed
to the air a heated container
that was freely open to the air
Only the open vessel developed
microorganisms. This further
helped to disprove abiogenesis
15. The Controversy Over Spontaneous Generation
John Needham & Lazzaro Spallanzani
The Question:
What causes tiny living things to appear in decaying broth?
Needhamās Hypothesis: Spontaneous generation.
Spallazaniās Hypothesis: Microbes come from the air. Boiling will kill them.
Needham >
Spallazani >
1713 - 1781
1729 - 1799
19. LOUIS PASTEUR (1822 - 1895)
ā¢ Disproved spontaneous
generation of microbes
The Golden ERA of Microbiology
20. PASTEURāS EXPERIMENT
trapped airborne organisms in cotton; he also heated the necks of flasks, drawing
them out into long curves, sterilized the media, and left the flasks open to the air.
In this way Pasteur disproved the theory of spontaneous generation
24. ā¢Solved the problem of spontaneous generation (1859) i.e. swan necked
flask.
Introduce the techniques of Pasteurization
62.80C for 30 min ļ Holder method
720C for 20 sec ļ Flash method
ā¢Introduced techniques of sterilization, developed steam sterilizer, hot air
oven & autoclave.
ā¢Development of methods & techniques for cultivation of
microorganisms.
ā¢Conclusive evidence for microorganisms in disease production.
ā¢He worked on diseases like ā anthrax, chicken cholera & hydrophobia.
ā¢Discovered the process of attenuation & development of vaccine. He
developed vaccines for chicken cholera, anthrax, rabies.