German bacteriologist Robert Koch (1843–1910) and French chemist Louis Pasteur are considered the founders of bacteriology. In 1864 Pasteur devised a way to slowly heat foods and beverages to a temperature that was high enough to kill most of the microorganisms that would cause spoilage and disease, but would not ruin or curdle the food. This process is called pasteurization.

By demonstrating that tuberculosis was an infectious disease caused by a specific species of Bacillus, Koch in 1882 set the groundwork for public-health measures that would go on to significantly reduce the occurrences of many diseases. His laboratory procedures, methodologies for isolating microorganisms, and four postulates for determining agents of disease gave medical investigators valuable insights into the control of bacterial infections.