Louis Pasteur Disproves The Doctrine of Spontaneous Generation

Spontaneous generation, also called abiogenesis, is the belief that some living things can arise suddenly, from inanimate matter, without the need for a living progenitor to give them life.

In the fourth century B.C., the Greek philosopher and scientist Aristotle argued that abiogenesis is one of four means of reproduction, the others being budding (asexual), sexual reproduction without copulation, and sexual reproduction with copulation. Indeed, the Greek goddess Gea was said to be able to create life from stones. Even Albertus Magnus (Albert the Great), the great German naturalist of the thirteenth century Middle Ages, believed in spontaneous generation, despite his extensive studies of the biology of plants and animals.

Doubts of Pasteur's thesis lingered until 1876. By this time Pasteur and his associate, C. Chamberland, had discovered that some bacteria have a resting spore stage during which they are resistant to the temperatures then used in sterilizing experimental cultures. They showed that, in the experiments of Pouchet, the presence of resistant spores in their hay infusion cultures accounted for the subsequent growth. By heating these cultures to 115-120 degrees centigrade, Chamberland destroyed the spores and sterility could be universally maintained in the infusions so treated. The age-old doctrine of spontaneous generation was finally demolished.

He exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to the growth medium, and even in vessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass. Nothing grew in the broths unless the flasks were broken open; therefore, the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth. This was one of the last and most important experiments disproving the theory of spontaneous generation. The experiment also supported germ theory.