If you've ever used a petri dish to grow and isolate different strains of bacteria, you can thank Fanny Hesse! She suggested to her husband to use agar in his petri dishes instead of gelatin, and changed microbiology for good.
If you've ever used a petri dish to grow and isolate different strains of bacteria, you can thank Fanny Hesse! She suggested to her husband to use agar in his petri dishes instead of gelatin, and changed microbiology for good.
Fundamental
Fanny Hesse was born in New York City in 1850 from Dutch parents. Despite her fundamental contribution to microbiology, she had no background in science. She worked as an unpaid assistant, illustrator and cook for her husband Walther Hesse, who was a laboratory technician for the German microbiologist Robert Koch.
Agar
In 1881, her husband got stuck while growing bacteria. He used a gelatine-based culture medium to grow the bacteria. However, during the cultivation process, the gelatin continued to liquefy due to substances produced by the bacteria and the high temperatures during the incubation. His attempt to grow the bacterial colonies on potato slices also failed. From her experience as a cook, Fanny knew that agar — a gelatinous substance extracted from the cell walls of certain red algae — was more heat-resistant than gelatin and not as easily digested by bacteria. Thanks to Fanny's insight, Koch was eventually able to isolate the bacteria that caused tuberculosis. Yet Hesse was never credited for her contribution.