title: Importance of subaerial biofilms and airborne microflora in the deterioration of stonework: a molecular study.
abstract: The study characterized the sessile microbial communities on mortar and stone in Milan University's Richini's Courtyard and investigated the relationship between airborne and surface-associated microbial communities. Active colonization was found in three locations: green and black patinas were present on mortar and black spots on stone. Confocal laser scanning microscopy, scanning electron microscopy and culture-independent molecular methods revealed that the biofilm causing deterioration was dominated by green algae and black fungi. The mortar used for restoration contained acrylic and siloxane resins that could be used by microorganisms as carbon and energy sources thereby causing proliferation of the biofilm. Epifluorescence microscopy and culture-based methods highlighted a variety of airborne microflora. Bacterial and fungal counts were quantitatively similar to those reported in other investigations of urban areas, the exception being fungi during summer (1-2 orders of magnitude higher). For the first time in the cultural heritage field, culture-independent molecular methods were used to resolve the structure of airborne communities near discoloured surfaces, and to investigate the relationship between such communities and surface-associated biofilms.
authors.affiliation: Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Polo
authors.forename: Davide
authors.initials: D
authors.lastname: Gulotta
authors.forename: Nadia
authors.initials: N
authors.lastname: Santo
authors.forename: Cristiano
authors.initials: C
authors.lastname: Di Benedetto
authors.forename: Umberto
authors.initials: U
authors.lastname: Fascio
authors.forename: Lucia
authors.initials: L
authors.lastname: Toniolo
authors.forename: Federica
authors.initials: F
authors.lastname: Villa
authors.forename: Francesca
authors.initials: F
authors.lastname: Cappitelli
mesh_terms: D000391:Air Microbiology; D001108:Architecture; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D003252:Construction Materials / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis; D005658:Fungi / Q000302:isolation & purification* / Q000502:physiology; D008856:Microscopy, Fluorescence / Q000379:methods; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S