Biologists and historians from Austria and Italy studied the composition of biological material in seven drawings by Leonardo da Vinci and discovered an unexpected variety of bacteria, fungi, and human DNA. The results of the study have been published in the journal Frontiers in Microbiology.
Scientists from the University of Natural Resources and Life Sciences in Vienna, led by Guadalupe Piñar, together with colleagues from the Central Institute of Archives and Books Pathology in Rome, used an innovative genome approach to analyze the microbiome of drawings called Nanopore, which combines the third generation sequencing method with the Genome Amplification Protocol (WGA).
This is the first full genome study of the works of the great Italian artist, but not the first use of such an approach in the art field. In 2019, Pignard and her colleagues, having studied microbiome, determined the storage conditions and possible geographical origin of three statues requisitioned from smugglers. And this year, the analysis of the microbiome of ancient parchments allowed us to find out the origin of the skins that were used for their manufacture a thousand years ago.
“The sensitivity of the Nanopore sequencing method offers an excellent tool for monitoring objects of art,” the words of Pignard are quoted in the press release of the publishing house. – It allows the microbiome to be evaluated and its variations to be visualized. This approach can be used to create a bio archive of objects’ history.
Despite the absence of visible damage to the paper, the researchers found traces of unexpectedly large amounts of bacteria. In general, the bacteria dominated the mushrooms, while previously it was believed that the paper media was dominated by mushrooms, and it is they that contribute to the destruction of designs over time, so the measures aimed at preserving the works were mainly directed against mushrooms.
Researchers believe that a large proportion of these bacteria, typical for the human microbiome, were left during restoration work, and the bacteria from the insect microbiome are likely to be brought along with fly excreta.
The second interesting observation is the presence of a large amount of human DNA. The authors note that there is no reason to claim that this is the DNA of the master himself. It is more likely that these traces were left by restorers for many years.
The authors of the study managed to establish a geographical correlation of both bacterial and fungal communities. Their analysis indicates that the drawings were in Turin and Rome for a long time.
The authors believe that with the help of the method developed by them it is possible to create biological “fingerprints” of the most significant works of art, which will not only allow learning a lot about the history of their creation and storage but also provide them with additional protection.