Georg Friedrich Schroder and Theodor von Dusc

Georg Friedrich Schroder and Theodor von Dusch allowed air to enter a flask of heat-sterilized medium after that it has been passed through sterile cotton wool.
No growth occurred in the medium even though the air had not been heated.

Felix Pouchet

French naturalist Felix Pouchet claimed in 1859 to have carried out experiments proving that microbial growth could occur without air contamination.

Louis Pasteur

Louis Pasteur (1822–1895) to settle matter once and for all. Pasteur first filtered air through cotton and found that objects resembling plant spores had been trapped.
If a piece of cotton was placed in sterile medium after air has been filtered, microbial growth occurred.
He placed nutrient solutions in flasks,heated necks in a flame, and drew them out into a variety of
curves, while keeping ends of the necks open to the atmosphere.
Pasteur boiled the solutions for a few minutes and allowed them to cool.
No growth took place in the contents of the flasks were exposed to the air.
Pasteur pointed out that no growth occurred because of dust and germs trapped on the walls of the curved necks.
If the necks were broken, growth commenced immediately.

Pasteur has not only resolved by 1861 but also had shown how to keep solutions sterile.

John Tyndall

English physicist John Tyndall (1820–1893) dealt a final
blow to spontaneous generation in 1877 by demonstrating that
dust carries germs and if dust was absent, broth remained sterile even if directly exposed to air.
During,course of his studies, Tyndall provided evidence for the existence of exceptionally heat-resistant forms of bacteria.

Ferdinand Cohn

Independently,German botanist Ferdinand Cohn (1828–1898) discovered existence of heat-resistant bacterial endospores.

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