Ricerc@Sapienza

A white deposit covering the walls in the Stanza degli Scudi of the Tomba degli Scudi, Tarquinia, Italy,
has been investigated. In this chamber, which is still preserved from any kind of intervention such as
cleaning and sanitization, ancient Etruscans painted shields to celebrate the military power of the
Velcha family. Scanning electron microscopy analysis has revealed the presence of characteristic
nanostructures corresponding to a calcite secondary mineral deposit called moonmilk. Analysis of the
microbial community identified Proteobacteria, Acidobacteria and Actinobacteria as the most common
phyla in strong association with the moonmilk needle fibre calcite and nanofibers of calcium carbonate.
Employing classical microbiological analysis, we isolated from moonmilk a Streptomyces strain
able to deposit gypsum and calcium carbonate on plates, supporting the hypothesis of an essential
contribution of microorganisms to the formation of moonmilk.