Fanny Hesse


Fanny Hesse is best known for her work in microbiology alongside her husband, Walther Hesse. Together they were instrumental in developing agar as a medium for culturing microorganisms.

Biography

Hesse was born in 1850 in New York City to Gottfried Elishemius, a wealthy import merchant, and his wife, Ceclie Elise. She met her husband and research partner, Walther Hesse, in 1872 while in Germany. They were engaged in 1873, and married in 1874 in Geneva.

Research contributions

Hesse worked in an unpaid capacity to assist her husband through preparing bacterial growth media, cleaning equipment and producing illustrations for publications.
In 1881, while her husband was working in the laboratory of German physician and microbiologist Robert Koch, Hesse suggested that agar was preferable to gelatin for cultivating bacteria. She was aware of the properties of agar as a gelling agent that maintained its gel properties at warm temperatures through using it at home to make puddings and jellies. A neighbour who had lived in Java had introduced agar to her when she lived in America.
This led to Koch using agar to cultivate the bacteria that cause tuberculosis.
Although Koch, in an 1882 paper on tuberculosis bacilli, mentioned he used agar instead of gelatin, he did not credit either Hesse, or mention why he made the switch. Hesse's suggestion never resulted in financial benefit for the Hesse family.