ABSTRACT
The Acidobacterium division represents a practically unknown but apparently widely distributed group within the Bacteria. The Acidobacterium division was the second dominating identified phylogenetic group after the Proteobacteria in all the three caves. There are: Altamira Cave, Tito Bustillo Cave and La Garma Cave. The identification of members of the deep-branching Acidobacterium division in Altamira cave paintings represented the first report for subterranean environments. Information on the microbial community structure in caves with Paleolithic paintings is rather low, but necessary in order to gain more knowledge on their possible impact on the valuable paintings. The finding of complex and partly unknown bacterial communities in cave Paleolithic paintings herein reported deserves attention, since it has been shown that microorganisms can affect painting pigments. The degradation and discoloration of pigments, as well as the formation of pigmented biofilms, the dissolution of metals by acids and chelating agents, and biomineralisation are some of the worst damages triggered by microbial growth.
