Robert Koch (1843–1910) was a pioneering German physician and microbiologist whose work laid the foundation for modern bacteriology.

Koch is best known for his development of Koch’s postulates, a set of criteria for establishing a causal relationship between a microorganism and a disease, which proved a rigorous framework for identifying pathogens. His discovery of the bacterium Mycobacterium tuberculosis as the causative agent of tuberculosis in 1882, along with his work on the cholera bacterium Vibro cholerae, significantly advanced the understanding of infectious diseases. Koch’s meticulous research and techniques, including the use of staining and culturing methods, revolutionized the study of bacteria and contributed to the development of effective treatments and public health measures.

His contribution earned him the Nobel Prize in Physiology or Medicine in 1905 and cemented his legacy as a key figure in the field of microbiology.