Biodiversity of Phototrophic Biofilms Dwelling on Monumental Fountains

Amongst the stone monumental assets, artistic fountains are particularly affected by microbial colonization due to constant contact with water. The development of a conspicuous microbial patina is the cause of biodegradation processes related with physical-chemical and aesthetical alterations. The microbial diversity of the patina dwelling on four fountains (two from Florence, Italy and two from Granada, Spain) was investigated using traditional and/or molecular techniques. Cyanobacterial diversity was also investigated through a polyphasic characterization of strains isolated from the studied fountains. Data collected on the four fountains were compared with an overview of reported biodiversity of the phototrophic patina developed on various fountains of Italy and Spain. The results indicated many similarities as regard the phototrophic biodiversity for all the investigated fountains. Automated ribosomal RNA intergenic spacer analysis (ARISA), a molecular fingerprint tool, was used to examine the eubacterial and cyanobacterial community for two of the investigated fountains. PCA analysis of ARISA profiles strengthened the results obtained by traditional methods and revealed separate clusters, as a consequence of different microenvironmental conditions for each fountain.