Louis Pasteur was a French biologist, microbiologist and chemist who lived from 1822-1895. He made several groundbreaking discoveries that helped establish the germ theory of disease and vaccinations. Some of his major contributions include discovering that microorganisms cause fermentation and spoilage, developing the process of pasteurization to kill pathogens in food, disproving the theory of spontaneous generation, and developing the first vaccines for rabies and anthrax. He founded the Pasteur Institute in Paris to produce biological medicines and research microbiology.