"There is a social and political need to protect and preserve European Cultural Heritage (CH). Outdoor CH stoneworks can be damaged by physical and chemical processes including deterioration processes caused by microorganisms. To effectively protect and maintain long-term conservation of European CH stonework, it is vital to identify the active components of the microbial community that cause the most damage in the biodeterioration processes and define their specific roles. Research in this area has been initially limited to the use of cultivation studies. More recently, in the last decade, research through the application of cultural-independent molecular methods focused on the structural analysis of the microbial community, detection of specific microbial agents, and identification of microorganisms present in the environments where biodeterioration occurs, have been carried out. But only few studies have been performed for the detection of metabolically active components in the biodeterioration processes in prehistoric paintings in caves. Therefore the proposed project is innovative in the CH field, and it focuses on the identification of the active “key players” in the biodeterioration processes and on the understanding of their function and activity. The project will use the most advanced techniques in the microbial molecular ecology including Whole Genome Amplification, 16S rRNA gene, functional gene and RNA analyses to investigate the active components of the microbial community colonising outdoor CH stoneworks. The project has a multidisciplinary approach, based on microbiology, molecular biology, and biogeochemistry linking in-situ with lab-chamber based studies to assess the development and population dynamics of microbial communities on stone. This multidisciplinary approach is essential for a better understanding of the microbial diversity and functional activity in the processes that alter our CH patrimony."