Altamira cave Paleolithic paintings harbor partly unknown bacterial communities

Abstract

Since it has been reported that microorganisms can affect painting pigments, Paleolithic painting microbiology deserves attention. The present study is the first report on the bacterial colonization of the valuable Paleolithic paintings in the famous Altamira cave (Spain). One sample taken from a painting area in the Polychromes Hall was analyzed culture-independently. This was the first time microbiologists were allowed to take sample material directly from Altamira paintings. Identification methods included PCR amplification of 16S rRNA genes (16S rDNA) and community fingerprinting by denaturing gradient gel electrophoresis (DGGE). The applied approach gave insight into a great bacterial taxonomic diversity, and allowed the detection of unexpected and unknown bacteria with potential effects on the conservation of the painting. Regarding the number of 29 visible DGGE bands in the community fingerprint, the numbers of analyzed clones described about 72% of the phylogenetic diversity present in the sample. Thirty-eight percent of the sequences analyzed were phylogenetically most closely related to cultivated bacteria, while the majority (62%) were most closely related to environmental 16S rDNA clones. Bacteria identified in Altamira were related with sequence similarities between 84.8 and 99.4% to members of the cosmopolitan Proteobacteria (52.3%), to members of the Acidobacterium division (23.8%), Cytophaga/Flexibacter/Bacteroides phylum (9.5%), green non-sulfur bacteria (4.8%), Planctomycetales (4.8%) and Actinobacteria (4.8%). The high number of clones most closely related to environmental 16S rDNA clones showed the broad spectrum of unknown and yet to be cultivated bacteria in Altamira cave.

Metabolically active Crenarchaeota in Altamira Cave

“…The bacterial components of the communities have been studied in detail somewhere else and were mainly composed of Proteobacteria and Acidobacteria [9,22,31].…”

“…A long-term microbiological study is being conducted on Altamira Cave [10,22]. This report is a contribution to deciphering the complex active microbial communities inhabiting cave niches.…”

Diversity and biosynthetic potential of culturable aerobic heterotrophic bacteria isolated from Magura Cave, Bulgaria

“…Caves can be considered extreme environments for life providing ecological niches for highly specialized microorganisms (Schabereiter-Gurtner et al, 2002b). These microorganisms, called extremophiles, produce enzymes that are functional under extreme conditions (Van den Burg, 2003).…”

“…Although providing extreme conditions for life, the caves are colonized by diverse psychrophilic (cold-loving) and psychrotolerant (cold-adapted) microorganisms that are able to grow in these environments (Schabereiter-Gurtner et al, 2002a;Barton & Northup, 2007). Processes of disintegration and formation of cave saltpeter, mineral oxides accumulations, coloration, and moonmilk deposits in many karstic caves have been linked with microbial activity (Castanier et al, 2000).…”

“…The literature on microbial communities in subterranean environments is mainly restricted to caves found in Spain, Italy, France, Romania, and the USA. A long-term microbiological study of the cave microflora is being conducted in Altamira Cave (Spain) and Lascaux Cave (France), both containing Paleolithic paintings (Schabereiter-Gurtner et al, 2002a;Bastian et al, 2009).…”