Characterization of biodegradation in a 17th century easel painting and potential for a biological approach.

It is important to characterize the microorganisms involved in biodeterioration processes to understand their effects on cultural assets and to define an efficient strategy for protecting artworks, monuments, and buildings from microbiological recolonization. In this study, we analyzed the microbial communities dwelling on the verso (front) and recto (back) sides of a 17th century easel painting attributed to Carlo Bononi, an Italian artist of the first Baroque period. Cultivable bacteria and fungi colonizing the painting were isolated and identified in order to characterize the microbial community possibly involved in deteriorating the pictorial layer of the painting. The isolated bacterial strains belonged to the Staphylococcus and Bacillus genera. Furthermore, culture-dependent techniques and SEM/EDS analyses revealed the presence of filamentous fungi of the genera Aspergillus, Penicillium, Cladosporium, and Alternaria. The chemical compositions of pigments were consistent with typical 17th century paintings, and some of the identified pigments, namely red lac and red and yellow earths, could be exploited as nutrient sources by painting-associated microorganisms. The study also evaluated, in vitro, the potential decontaminating activity of a biocompound, containing spores of Bacillus subtilis, Bacillus pumilus, and Bacillus megaterium. The results indicated the ability of this biocompound to counteract the growth of contaminating microorganisms that are potentially dangerous to the painting, suggesting the potential use of these microorganisms to prevent biodeterioration of artworks.

A Neanderthal deciduous human molar with incipient carious infection from the Middle Palaeolithic De Nadale cave, Italy.

OBJECTIVES: The aim of the study is the assessment of Nadale 1, a Neanderthal deciduous tooth recently discovered in Northeastern Italy in the De Nadale cave (Middle Palaeolithic). Together with the clear archaeological context of the site, this study brings new insight on Neanderthal behavior and dental morphological variability. MATERIALS AND METHODS: We used microCT data to provide a morphological description and morphometric analysis (diameter measurements and dental tissue volumes) of the Nadale 1 human tooth. Microwear analysis, taphonomical investigation and caries identification were performed using a stereomicroscope and Scanning Electron Microscope. RESULTS: In terms of morphology (i.e., incipient tuberculum molare, marked mesial marginal ridge and well-developed mid-trigonid crest connecting the protoconid and the metaconid, deep anterior fovea) and size, Nadale 1 presents features frequently observed in Neanderthal lower first deciduous molars. Microscope investigations reveal the presence of a small pit which could be correlated to an incipient caries. CONCLUSION: Nadale 1 expands the Italian Middle Palaeolithic fossil record and provides further information on Neanderthal dm1s in terms of dimensional and morphological variability. Furthermore, the presence of an incipient caries brings further data on Neanderthal diet.