Robert Koch, a German scientist and physician, is known as the father of bacteriology because of his development for Koch's postulates. He became famous for isolating Bacillus
… anthracis (1877), the Tuberculosis bacillus (1882) and Vibrio cholerae (1883) Louis Pasteur, a French chemist and microbiologist, is regarded as the father of microbiology. He was best known to the general public for inventing a method to treat milk and wine in order to prevent it from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand Cohn and Robert Koch. He worked chiefly in Paris. Bacteriology is a subcategory of microbiology, as there are other subcategories such as virology, mycology, parasitology, etc. According to most microbiology textbooks, Antonie Van Leeuwenhoek(1632-1723) is also regarded as the father of microbiology, but in fact Antonie Van Leeuwenhoek is regarded as the father of microscopy. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology. Using his handcrafted microscopes, he was the first to observe and describe single-celled organisms, which he originally referred to as animalcules, and which are now referred to as microorganisms. He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa, and blood flow in capillaries (small blood vessels). Van Leeuwenhoek did not author any books, although he did write many letters. (MORE) 
