Analysis of bacterial communities on an antique stained glass window

Microbial corrosion of glass causes problems for historical glass samples as well as for technical uses of glass. The first report of biodeterioration of glass dates back to the beginning of XX century. But until now the effect of microbial activity on corrosion phenomena is poorly documented in the literature. Only a few studies have been published concerning the microflora growing on glass surfaces and molecular techniques have been used to identify microrganisms in a very few. In studies on cultivable organisms, fungi seem the dominant group. The present work is based on the characterization of microbial communities on a historical window glass of the Florence Cathedral, the “Natività”, designed by Paolo Uccello from 1443 to 1444 and realized by Angelo Lippi. Culturable microbial strains were sampled from four of the 25 panels of the “Natività” in occasion of a recent restoration intervention due to presence of various kind of patinas ad crusts on the glass. About one hundred microorganisms were isolated, 50% bacteria and 50% fungi. Bacteria were submitted to morphological characterization and classified in the Gram group. For some strains, coming from different glass panels, the rDNA 16S gene was amplified and sequenced. Sequence analysis allowed to assign the tassonomic level of genus to these strains.