Portchester Castle sandstone Raw sequence reads. Portchester Castle sandstone

Studies on the microbial degradation of cultural heritage (CH) stoneworks have revealed diverse microbiota adapted to stresses such as low nutrients, aridity and high salinity, temperatures and radiation. However, the function of these microbial communities is still unclear. In this study, bacterial and archaeal diversity in exfoliated and dark encrustation sandstone at Portchester castle (UK) by 16S rRNA and functional gene analyses. Bacterial and archaeal communities from the exfoliated sites were distinctly different from the dark encrustation. These analyses detected genera linked to various extreme habitats and environmental conditions, potential functional roles and degradation abilities. Using the known capabilities of different detected genera it was possible to reconstruct complete nitrogen and sulfur cycles as well as autotropic carbon fixation and processes capable of degrading stone. Analysis of RNA from these low-biomass sites showed that many of the detected genera in these nutrient cycles were active in situ.Thus, CH stonework microbial communities are highly diverse and, potentially self-sustaining ecosystems capable of cycling carbon, nitrogen and sulphur and indeed to thrive and support itself where nitrogen and carbon fixation can provide the growth of a complex community and the stone biodeterioration processes mainly linked to alterations such as exfoliation and corrosion.