Pasteur was born at Dôle. He studied at Besanon and at the Cole Normale Supérieure, and held academic posts at Strasbourg, Lille and Paris, where in 1867 he became Professor of Chemistry at the Sorbonne. His principal work was in discovering that fermentations are essentially due to organisms, not spontaneous generation. He greatly extended Theodor Schwann's researches on putrefaction, and gave valuable rules for making vinegar and preventing wine disease, introducing in this work the technique of 'pasteurization', a mild and short heat treatment to destroy pathogenic bacteria.
After 1865 his research into silkworm disease revived the silk industry in southern France; he also investigated injurious growths in beer, splenic fever, and fowl cholera. His 'germ theory of disease' maintained that disease was communicable through the spread of micro-organisms, the virulence of which could be reduced by exposure to air, by variety of culture, or by transmission through various animals. He demonstrated that sheep and cows 'vaccinated' with the weakened bacilli of anthrax were protected from the harmful results of subsequent inoculation with the virulent virus; by the culture of antitoxic reagents, the prophylactic treatment of diphtheria, tubercular disease, cholera, yellow fever and plague was also found effective. In 1885 he introduced a similar treatment for hydrophobia (rabies).