Robert Koch's foundational research:

• Robert Koch (1876) conclusively demonstrated the germ theory of disease by proving that Bacillus anthracis was the specific causative agent of anthrax in sheep and cattle.
• Through isolation, pure culture on potato/gelatin, and reinoculation producing identical anthrax symptoms, he formulated the classic four Koch's Postulates.
• He subsequently applied them to Mycobacterium tuberculosis in 1882.