Actually, Louis Pasteur did not discover penicillin; that credit goes to Alexander Fleming. Penicillin was discovered in 1928 when Fleming observed that a mold called Penicillium notatum had antibacterial properties, effectively killing nearby bacteria in a petri dish.
Louis Pasteur, a pioneer in microbiology and immunology, made significant contributions to the understanding of germs and fermentation. He developed the germ theory of disease and pasteurization, which reduced spoilage and killed harmful microbes in food and drink.
While Pasteur’s work laid the foundation for future discoveries in medicine and microbiology, it was Fleming’s accidental discovery of penicillin that revolutionized the field of antibiotics and has saved countless lives since its introduction.