Microscopic, chemical, and molecular-biological investigation of the decayed medieval stained window glasses of two Catalonian churches

• Published in: International biodeterioration & biodegradation 2013-10, Vol.84 (100), p.388-400
• Main Authors: Piñar, Guadalupe, Garcia-Valles, Maite, Gimeno-Torrente, Domingo, Fernandez-Turiel, Jose Luis, Ettenauer, Jörg, Sterflinger, Katja
• Format: Article
• Language: English
• Subjects: Actinobacteria; Bacteria; bacterial communities; Bio-pitting; bioactive properties; Biodegradació; Biodegradation; Biodeterioration; biodiversity; Catalonia; Catalunya; chemical composition; Churches; Cladosporium; Decay; denaturing gradient gel electrophoresis; energy; energy-dispersive X-ray analysis; Fungi; Glass; Glass painting and staining; internal transcribed spacers; Mediterranean climate; Microbial communities; Mineral precipitation; Molecular methods; Patinas; Phoma; polymerase chain reaction; Proteobacteria; ribosomal DNA; ribosomal RNA; scanning electron microscopy; Similarity; Spectroscopy; Stained glasses; Stone; Vitralls; X-ray diffraction
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2012.02.008

We investigated the decayed historical church window glasses of two Catalonian churches, both under Mediterranean climate. Glass surfaces were studied by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD). Their chemical composition was determined by wavelength-dispersive spectrometry (WDS) microprobe analysis. The biodiversity was investigated by molecular methods: DNA extraction from glass, amplification by PCR targeting the16S rRNA and ITS regions, and fingerprint analyses by denaturing gradient gel electrophoresis (DGGE). Clone libraries containing either PCR fragments of the bacterial 16S rDNA or the fungal ITS regions were screened by DGGE. Clone inserts were sequenced and compared with the EMBL database. Similarity values ranged from 89 to 100% to known bacteria and fungi. Biological activity in both sites was evidenced in the form of orange patinas, bio-pitting, and mineral precipitation. Analyses revealed complex bacterial communities consisting of members of the phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Fungi showed less diversity than bacteria, and species of the genera Cladosporium and Phoma were dominant. The detected Actinobacteria and fungi may be responsible for the observed bio-pitting phenomenon. Moreover, some of the detected bacteria are known for their mineral precipitation capabilities. Sequence results also showed similarities with bacteria commonly found on deteriorated stone monuments, supporting the idea that medieval stained glass biodeterioration in the Mediterranean area shows a pattern comparable to that on stone. ► Na-rich and K-rich (or K–Ca-rich) glasses were distinguished and investigated. ► Biological activity evidenced orange patinas, bio-pitting and mineral precipitation. ► Bacteria belonged to Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria. ► Fungi were less diverse and belonged to species of the genus Cladosporium and Phoma. ► The microorganisms detected were related to the observed biodeterioration phenomena.