Biofilms in churches built in grottoes

Area of Science:

• Microbiology
• Geomicrobiology
• Art Conservation Science

Background:

• Votive chapels in grottoes are unique environments for microbial colonization.
• Understanding microbial communities is crucial for preserving historical sites.

Purpose of the Study:

• To investigate microbial life on rocks, walls, and paintings in two Italian grottoes.
• To correlate microbial diversity and biofilm characteristics with environmental factors.

Main Methods:

• Biofilm analysis using light and electron microscopy.
• Molecular techniques including DNA analyses and Automatic rRNA Intergenic Spacer Analysis.
• Geochemical analysis using X-ray diffraction and X-ray fluorescence.

Main Results:

• Identified eubacteria, cyanobacteria, and green algae species in biofilms.
• Observed variations in microbial species occurrence between the two grottoes.
• Documented differences in biofilm color and distribution influenced by climate and substrata.

Conclusions:

• Microbial communities in grottoes are shaped by climatic conditions and inorganic substrata.
• Specific microbial species can be endemic to particular grotto environments.
• This research provides insights into biodeterioration and preservation strategies for rock-art heritage.