TY - CONF A1 - Fuentes, Elsa A1 - Prieto, Beatriz A1 - Gorbushina, Anna T1 - Mixed model biofilm: interactions between algae, fungi and cyanobacteria and their effects on granite biodeterioration N2 - Granite, despite being one of the most widely used rocks for building material cultural heritage, is also one of the least studied. Previous works have shown that environmental parameters modulated by climate change will lead to changes in the microbial composition of biofilms grown on stone, but also to changes in the production of EPS, in the composition of pigments and, as a consequence, in the biodeterioration processes that this rock undergoes (Fuentes, 2023). Considering that the colonisation process is highly dynamic, small changes in climatic conditions can lead to the formation of different types of biofilms and diverse interactions between species. Knowing the contribution of the different organisms to the deterioration process is important both to anticipate the consequences that climate change will have on the deterioration of the granite, but also when addressing the processes of recolonization after cleaning, to ensure an improvement of the present situation. So, in order to continue my line of research on granite biodeterioration, the aim of this new project is to study the contribution of each type of organism (green algae, cyanobacteria and fungi) to the process of granite deterioration as well as the specific effect on each mineral, in addition to its role in the resilience and response of biofilms to environmental changes. With this main objective, the effect of the type of substrate on the composition of a model mixed biofilm formed by the fungus Knufia petricola, the algae Jaagichlorella sp. and the cyanobacterium Synechocystis sp. will be studied. The results obtained on granite will be compared with those obtained with other lithic types such as marble or limestone. Furthermore, it will be observed if the different ratios between organisms lead to changes in the capacity of these organisms to generate biodeterioration and to buffer climatic changes. Finally, the susceptibility of each mineral that makes up the granite - quartz, feldspars, micas - to biodeterioration mediated by each type of organism will be analysed. To address these questions, on the one hand, the response of the mixed biofilms as a whole will be evaluated by means of confocal microscopy, PAM, as well as the quantification of pigments and EPS, and on the other hand, the effect of these organisms on the deterioration of the substrates, through the use of SEM and TEM, which will allow the assessment of both the changes in porosity and the appearance of deterioration in the surface layers of the rock. This research will deepen the knowledge of the processes of granite deterioration, which have been limitedly studied in relation to microorganisms; but also aims to provide the scientific community with a model mixed biofilm to increase the reproducibility between experiments, one of the main limitations of this field of study. T2 - 19th International Biodeterioration and Biodegradation Symposium CY - Berlin, Germany DA - 09.09.2024 KW - Biofilm KW - Stone KW - Algae KW - Fungi KW - Cyanobacteria KW - Cultural heritage PY - 2024 AN - OPUS4-62272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -