Survey of microbes reveals some history of Da Vinci's drawings


Researchers sampled and sequenced microbes from seven of Leonardo da Vinci's drawings, including Portrait of a "Man in Red Chalk." Photo by Guadalupe Piñar, et al./Frontiers in Microbiology

Nov. 20 (UPI) -- Studying the community of microbes living in the guts of humans and animals can help scientists answer all kinds of biological and evolutionary questions, providing insights into the links between diet, environment and health.

But what can a microbiome say about a piece of art?

That's what an international team of researchers, including museum curators and bioinformaticians, wanted to find out when they sequenced the microbes living on seven different 15th century drawings of Leonardo da Vinci.

The results -- published Friday in the journal Frontiers in Microbiology -- revealed a surprising dominance of bacteria over fungi. Previously, researchers assumed fungi dominate the colonization of paper-based art.

As such, fungi and their biodeterioration potential are often the primary focus of scientists working to preserve or restore pieces of art.

Researchers suspect many of microbes that make up the bacterial community found on the five drawings were introduced by human handlers and restoration workers through the decades. But they estimate some of the bacteria was deposited by insects -- microbial signatures from 15th century fly excrement.

Scientists were also able to identify microbial signatures consistent with the drawings' geographic origins, though research suggests these geographic localization patterns are linked with modern museums and storage facilities, not 15th century Italy or Da Vinci's studio.

"The sensitivity of the Nanopore sequencing method offers a great tool for the monitoring of objects of art," lead study author Guadalupe Piñar said in a news release.

"It allows the assessment of the microbiomes and the visualization of its variations due to detrimental situations. This can be used as a bio-archive of the objects' history, providing a kind of fingerprint for current and future comparisons," said Piñar, a postdoctoral researcher at the University of Natural Resources and Life Sciences Vienna.

It's not the first time microbes have helped scientists study the history of ancient art. Researchers have previously used microbiome sequencing to identify the animal origin of the skins used for ancient parchments.

In 2019, Piñar and her colleagues used Nanopore sequencing to identify the likely origins and storage conditions of a trio of ancient statues confiscated from smugglers