During his career his position as a strong proponent of public health at times placed him at odds with his contemporaries, most notably Robert Koch. During his career Koch identified and isolated a large number of bacterial strains and was a supporter of the theory that these germs were the main causes of disease. This placed him at odds with Pettenkofer's broader approach to disease that involved many other environmental factors in addition to the activity of the germ of a disease. The two scientists conflicted most notably over the subject of cholera. In one specific case, Pettenkofer obtained bouillon laced with a large dose of "Vibrio cholerae" bacteria from Robert Koch, the proponent of the theory that the bacterium was the sole cause of the disease. He consumed the bouillon in a self-test in the presence of several witnesses on 7 October 1892. He also took bicarbonate of soda to neutralise his stomach acid to counter a suggestion by Koch that the acid could kill the bacteria. Pettenkofer suffered mild symptoms for nearly a week but claimed these were not associated with cholera. The modern view is that he did indeed have cholera, but was lucky to just have a mild case and he possibly had some immunity from a previous episode.