Culture-independent analyses of bacterial communities on paleolithic paintings and surrounding rock walls in karstic caves. Altamira, Tito Bustillo, La Garma and Llonín

Abstract

Paleolithic painting microbiology deserves attention, since it has been reported that microorganisms can affect painting pigments. Caves represent nutrient-poor ecosystems subjected to stable and low temperatures and although providing extreme environments for life, they are inhabited by a variety of microorganisms. However, few studies on cultivated bacteria in caves have been conducted so far. While these cultivation-based studies most probably revealed just a very minor and not representative part of cave population, culture-independent identification methods allowed the detection of unexpected and unknown bacteria and gave insight into a greater bacterial taxonomic diversity in caves (Engel et al. 2001; Holmes et al. 2001; Northup et al. 2000; Vlasceanu et al. 2000). Recently, the combination of PCR amplification of bacterial 16S rRNA genes (16S rDNA), phylogenetic sequence analyses, and genetic community fingerprinting by denaturing gradient gel electrophoresis (DGGE) was shown to be a proper method to study the bacterial communities on the valuable Paleolithic paintings and on the rock surfaces near the paintings in four Spanish caves of Altamira, La Garma, Llonín, and Tito Bustillo (Schabereiter-Gurtner et al. 2001, 2002a, b, c).