Scientists discover 20 bacterial species on Rembrandt's night watch

Microbiologists in the Netherlands discovered 20 species of bacteria on Rembrandt van Rijn's famous 1642 painting, Die Nachtwache.

The discovery occurred during Operation Nachtwache, a long-term research and restoration project at the Rijksmuseum in Amsterdam. Researchers collected around 60 samples from the nearly 400-year-old canvas to study the biological life on the artwork.

While the team did not find any pests that threaten the painting, they identified various microbes, including types typically found on human skin and those that usually live on plant roots. The scientists also identified a specific bacterial species first discovered in a Japanese sugar refinery in 2013. Experts say it is unlikely these microbes originated from Rembrandt himself, but they do not know how the bacteria reached the painting or how long they have lived there.

The museum plans to display these colonies at the Micropia microbe museum in Amsterdam.