Microbial compositon of Saharan dust plumes deposited as red rain in Granada (Southern Spain) Navarro, Azahara Moral García, Ana Isabel Del Weber, Bettina Weber, Jens Molinero García, Alberto Delgado, Rafael Párraga, Jesús Martínez-Checa, Fernando Aerobiology Saharan dust Nanobacteria Red rain Iberulite Biofilm During durst storms, also biological material is transported from arid areas such as the Sahara Desert. In the present work, rain samples containing significant amounts of mineral dust have been collected in Granada during different red rain episodes. Biological features (bacteria, biofilm, pollen grain and fungal spore) as well as size-particle distribution and mineralogical composition were studied by SEM. Nanobacteria were observed for the first time in red rain samples. A preliminary metabarcoding analysis was performed on three red rain samples. Here, Bacillota made up 18 % and Pseudomonadota 23 % of the whole prokaryotic community. The fungal community was characterized by a high abundance of Ascomycota and, dependent on the origin, the presence of Chytridiomycota. By means of 16S rRNA sequencing, 18 cultivable microorganisms were identified. In general, members of the phyla Pseudomonadota and Bacillota made up the majority of taxa. Some species, such as Peribacillus frigoritolerans and Bacillus halotolerans were isolated during three different red rain episodes. Generally, red rain carries a wide variety of microorganisms, being their ecosystem and health effects largely unknown. 2024-02-01T09:59:49Z 2024-02-01T09:59:49Z 2024-02-25 journal article Navarro, A., Del Moral, A., Weber, B., Weber, J., Molinero, A., Delgado, R., ... & Martínez-Checa, F. (2023). Microbial composition of Saharan dust plumes deposited as red rain in Granada (Southern Spain). Science of The Total Environment, 169745. https://hdl.handle.net/10481/87900 https://doi.org/10.1016/j.scitotenv.2023.169745 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Abasiofiok Ibekwe