In memoriam Jacques Waisvisz (1918-2020): his discovery of natamycin

Jacques Waisvisz, the man who discovered the substance natamycin for Koninklijke Gist brocades, died on  February 5th, 2020.

The Jewish Waisvisz flees with his parents to France in 1942 because of the Second World War, where they lose sight of each other after a raid. Via wanderings, Jacques arrives in England, where he is trained as a paratrooper. With his regiment he fights in Belgium and Italy and also participates in D-Day in 1944. When he returns to Rijswijk in 1945, his father, mother and brother Gabriel are still alive. The rest of the family died in Sobibor extermination camp. In September 1945, Jacques resumed his studies in chemistry and after completion he started working at the Nederlandsche Gist- en Spiritus Fabriek. As head of the organic lab of the later Gist-brocades, he will discover natamycin.


Yeast brocades had set up a program shortly after World War II to search for new bacteria and make natural antifungals. These bacteria had to come from soil samples. The famous professor Martinus Willem Beijerinck has always said "All bacteria are on your heels". A new, simple approach was devised. They asked employees and business contacts who went to faraway places to take samples of the soil they walked on.

This approach quickly proved successful. Among the hundreds of jars that ended up in the Delft laboratories thanks to various employees, was the sample containing the bacterium Streptomyces natalensis, named after the South African area of ​​origin Kwazulu Natal. The soil sample came with Johanna Westerdijk, director of the Central Bureau for Mold Cultures, who traveled to South Africa in 1952. The bacteria secretes a substance, natamycin, which has an anti-fungal function. For example, it is used in cheese and sausage coatings to prevent spoilage.

Efficacy of natamycin

Natamycin is a natural substance produced by fermentation from the culture "Streptomycis Natalensis". In 1954 it was already discovered that natamycin has an active effect against a broad spectrum of fungi and yeasts. Only since 2012 has the technical mechanism been investigated and discovered. Natamycin has a unique external effect, it kills the fungi and yeasts by stopping the supply of nutrients. This prevents the cell from building up immunity and preserves the effectiveness of natamycin for the long term. Due to its proven long-term effectiveness, natamycin is being applied more and more to other products in addition to cheese production and the end is nowhere in sight.