Chap 5: A study for monitoring and conservation in the Roman Catacombs of St. Callistus and Domitilla, Rome (Italy)The Conservation of Subterranean Cultural Heritage

The economic and archaeological value of Roman Catacombs is worldwide recognized. But as many other underground sites open to the public they are subjected to biological attack, that in the long term can compromise their conservation. Cyanobacteria and chemoorganotrophic bacteria were the major microorganisms forming phototrophic biofilms on the lithic illuminated surfaces present along the tourist pathway. Studies were for this reason undertaken in order to characterize the microenvironment of two Roman hypogea, St. Callistus and Domitilla in Rome (Italy), and to assess the level of damage, to identify the microorganisms involved and to develop innovative strategies for the prevention and limitation of deterioration processes. Non-invasive techniques were applied for the microbial sampling and nondestructive analyses and remediation procedures have been used for the research. Promising results were obtained opening a new era in the conservation of valuable Cultural Heritage.