Cesareo Saiz-Jimenez is a Research Professor at the Institute for Natural Resources and Agricultural Biology, Spanish National Research Council, Seville, Spain. He holds a Ph.D. in Biology (1975) from the University of Madrid, Spain, and in Chemical Engineering and Materials Sciences (1987) from the Technical University of Delft, The Netherlands. Since 1987 he has received funding from the European Commission, in Environment Research Programmes (1986-1994), Environment and Climate (1995-1998), The City of Tomorrow (1999-2002), and the 6FP and 7FP (2003-2013) as well as from national research programmes. He has participated in a total of 22 European projects and was national coordinator of EUROCARE (EUREKA programme), and Spanish manager of the City of Tomorrow and the Cultural Heritage, Key Action 4 from the European Commission. He is the current coordinator of the Spanish Network for Science and Technology for the Conservation of Cultural Heritage. This network comprises over 90 teams from universities, research centres, museums and SMEs. He has written over 450 papers published in international journals, congresses and workshops, as well as edited a number of books on different topics. Most of his research activity is aimed at the study of microbial communities in different terrestrial and aquatic ecosystems, biogeochemistry of terrestrial environments, and effects of air pollution on building materials. Particular attention was devoted to cultural heritage deterioration processes by microorganisms. In the last 20 years he has focused his research on the microbiology of subterranean environments (caves, ancient tombs, catacombs, mines). Papers issuing from this research describe e.g. the microbial ecology of caves such as Altamira in Spain, Lascaux in France and Grotta dei Cervi in Italy, microbe-mineral interactions, the biogeochemical cycle of elements, and the biodeterioration of rock art and mural paintings.