Genetic Characterization of Epilithic Cyanobacteria and Their Associated Bacteria

Epilithic phototrophic biofilms develop inside Roman Necropolis and Catacombs on rock surfaces exposed to artificial light sources and are composed by a microbial consortium dominated by cyanobacteria. In this work, six non-axenic cultures of Leptolyngbya sp. strains isolated from biofilms from different Roman hypogea and maintained in cultures from 11 to 20 years were analysed along with their associated bacteria isolated in culture. The employment of PCR-fingerprinting techniques, using HIP1 and ERIC derived primers, allowed the clustering in three groups of the six Leptolyngbya strains and the typing of their isolated bacteria. The bacterial fingerprinting patterns were in agreement with the 16S rRNA gene sequencing and showed the presence in Leptolyngbya isolates of Pseudomonas, Stenotrophomonas, Agrobacterium and Bacillus representatives that were detected also in biofilms sampled from catacombs.