Fungal strains isolated from rocks and lichens collected in the Antarctic ice-free area of the Victoria Land, one of the coldest and driest habitats on earth, were found in two phylogenetically isolated positions within the subclass Dothideomycetidae. They are here reported as new genera and species, Recurvomyces mirabilis gen. nov., sp. nov. and Elasticomyces elasticus gen. nov., sp. nov. The nearest neighbours within the clades were other rock-inhabiting fungi from dry environments, either cold or hot. Plant-associated Mycosphaerella-like species, known as invaders of leathery leaves in semi-arid climates, are also phylogenetically related with the new taxa. The clusters are also related to the halophilic species Hortaea werneckii, as well as to acidophilic fungi. One of the latter, able to grow at pH 0, is Scytalidium acidophilum, which is ascribed here to the newly validated genus Acidomyces. The ecological implications of this finding are discussed.

The main objective of this work was the comparative analysis of a large number of bacterial strains isolated from biodeteriorated surfaces in three different sites, namely the catacombs of St. Callistus in Rome, Italy, the catacombs dedicated to St. Agatha in Rabat, Malta and the Cave of Bats in Zuheros, Spain. Our results showed that even considering only culturable chemoorganotrophic bacteria the variability is very high, reflecting the great variety of microhabitats present. Hence any strategies to prevent, control or eliminate the biofilm-embedded microbiota from an archeological surface should take into account a number of considerations as stipulated in our study.