ABSTRACT
ABSTRACT: Numerous studies on caves and other subterranean environments have revealed the presence of microbial communities colonizing the walls and ceilings. The colonizations form biofilms of different colours: white, grey, yellow, pink, etc. In the case of white colonizations, most of the studies have been carried out using molecular techniques. Nevertheless, there is not much information obtained by cultivation techniques. White colonizations are particularly important in biodeterioration processes in caves (Altamira), or catacombs and tombs (Etruscan and Roman necropolises). Therefore, the aim of this work is the study of the cultivable fraction of white colonizations in two Spanish caves: Gruta de las Maravillas (Aracena, Huelva) and Cueva del Tesoro (Rincón de la Victoria, Málaga). In both caves the most abundant microorganisms isolated from white colonizations belong to the phylum Actinobacteria followed by the phylum Firmicutes. In this pool of bacterial diversity we have characterized following a polyphasic approach two novel species, Paenibacillus sp. isolated from Gruta de las Maravillas and Acinetobacter sp. isolated from Cueva del Tesoro. The discovery of new species allowed us to know their physiology and role in the biogeochemical cycle and cave biodeterioration processes.
