Synthetic consolidants attacked by melanin-producing fungi: case study of the biodeterioration of Milan (Italy) cathedral marble treated with acrylics.
Monuments and artistic stone surfaces are often consolidated and protected with synthetic polymers, in particular, acrylics. Although it is generally thought that acrylic polymers are resistant to biodeterioration, we report for the first time the systematic occurrence of dematiaceous meristematic fungi on many marble samples of the cathedral in Milan (Italy) previously treated with this material. Fourier transform infrared spectroscopy applied to the Milan cathedral stone samples revealed characteristic features of biodeteriorated synthetic resins that differentiated them from the aged but nonbiodeteriorated samples. Samples showing biological colonization were analyzed for the presence of fungi. Cultivation and morphological characterization and methods independent from cultivation, such as denaturing gradient gel electrophoresis coupled with partial 18S rRNA gene sequencing and immunofluorescence staining with melanin-binding antibodies, showed that melanin-producing species are heavily present on stone surfaces protected with acrylic resins. This observation raises the question of the effectiveness of acrylics in protecting stone artworks.
Cappitelli
Francesca
F
Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Via Celoria 2, Milan, Italy. francesca.cappitelli@unimi.it
Nosanchuk
Joshua D
JD
Casadevall
Arturo
A
Toniolo
Lucia
L
Brusetti
Lorenzo
L
Florio
Sofia
S
Principi
Pamela
P
Borin
Sara
S
Sorlini
Claudia
C
D000180:Acrylic Resins; D001154:Art; D001203:Ascomycota / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D001673:Biodegradation, Environmental; D002119:Calcium Carbonate / Q000378:metabolism*; D003252:Construction Materials / Q000382:microbiology*; D004591:Electrophoresis, Polyacrylamide Gel; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D007558:Italy; D008543:Melanins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA; D017550:Spectroscopy, Fourier Transform Infrared
D000180:Acrylic Resins; D008543:Melanins; D012337:RNA, Ribosomal, 18S; D002119:Calcium Carbonate