Answer:
His work, which was documented and repeatable, contradicted the accepted cell theory, so a change in the theory was required.
Explanation:
Cell theory prior to Pausteur's experiment argued that cells could continually and spontaneously originate from nonliving matter. This theory was called abiogenesis and was refuted after Pasteur's experiments.
Adept of the biogenic theory, Louis Pasteur in 1861, through an experiment, was able to conclusively demonstrate the impossibility of spontaneous generation of life (hypothesis so defended by the abiogenists), ie, the origin of life is only possible from living matter, from a preexisting living being.
In the experiment, Pasteur added nutritious broth to an elongated necked glass flask. He then heated the neck, giving it a curved tube shape (swan neck). After modeling, it proceeded to boil the broth, subjecting it to a temperature until the sterile state (absence of microorganism), but allowing the broth to have contact with the air.
After boiling, leaving the flask to rest for a long time, he noticed that the liquid remained sterile. This was possible due to two factors:
The first was due to the physical obstacle caused by the sinuosity of the neck. The second is caused by the adhesion of impurity particles and microorganisms to the water droplets formed on the inner surface of the neck during steam condensation, emitted by heating and cooling when at rest.
After a few days, checking for non-contamination, Pasteur broke the neck, exposing the inert broth to airborne microorganisms, favoring suitable conditions for germ proliferation.
This scientist, besides contributing to the end of the abiogenist mistake, also developed, from the application of simultaneous heating and cooling, the pasteurization technique widely used for food preservation.