Bioincrustations in the Church of Saint Maria of Piedigrotta (Pizzo Calabro, Italy) P. Cennamo1, C. Marzano2, A. Giorgio2, P. Caputo2, A. Moretti2 1 Università degli Studi Suor Orsola Benincasa, Facoltà di Lettere, Conservazione dei Beni Culturali, Via Santa Caterina da Siena 37, 80135 Naples, Italy. 2 Università degli Studi di Napoli Federico II, Sezione di Biologia Vegetale, Via Foria 223, 80139 Naples, Italy. Biodeterioration of stone monuments is commonly caused by the development of phototrophic organisms. Various investigations have been aimed at identifying the organisms composing the bioincrustations, as well as at understanding the interations between biodeteriogens and the substratum. Authors present here the results of the study carried out in the Church of Saint Maria of Piedigrotta in Pizzo Calabro (Calabria, Southern Italy). The Church is escavated in a large block of lithic sandstone located ten meters from the sea; inside the Church, statues made by the same material and frescoes are exposed to natural light. Marine salinity and high humidity values associated with the high porosity of the stones causes a strong erosion of the statues and frescoes. Such environmental conditions also determine the formation of bioincrustations appearing as green and black biofilms on the stones. Biofilm samples from twenty sites of the Church were collected and placed into sterile plastic vials and transferred to laboratory, where they were grown in different media (for bacteria, cyanobacteria, algae and fungi). Taxonomic identification was carried out by light and electron microscopy, as well as by molecular analyses (DGGE, clone libraries and sequences). Results show that the dominant microorganisms are cyanobacteria and algae. The cyanobacteria diversity was found to be relatively high, including a community of halophytic species (Alveolata sp., Belliella sp.). On the contrary, the diversity of algae was found to be low. Identified algae belong to Chlorococcales, such as Scenedesmus obliquus, Pseudococcomyxa simplex, Chlorella sp. and Ulothrix sp., and to Diatoms Eunotia sp. and Navicula sp. This work was supported by INNOVA (Regional Centre of Competence for Development and Transfer of Innovation for Cultural and Environmental Heritage).