DUST Desert Upon Sardinian Territory

Intercontinental dust transport represents one of the mechanisms of microbial dispersion, contributing to biodiversity of ecosystems and impacting on human health when of pathogenic nature. Studies on airborne dust microbiology have just begun reporting variable densities of microorganisms depending on seasons and environmental conditions, in particular a low number of culturable microrganisms, only 1%.In this study, a combined culture-dependent and independent DNA-based analyses via NGS of 16S genes was applied for the first time to investigate the airborne dust microbiology in air sampled during dust events at two opposite coastal sites of italian Island Sardinia, which represents the crossroad of wind circulation from Africa towards Europe. The results of culturable method showed that microrganisms possessing adaptive strategies to persist in the atmosphere during dust transportation survived, as Gram positive Bacillus spp and filamentous fungi.By using NGS analysis, we observed distinct differences in bacterial community composition. A major conserved core microbiome was evidenced but increases in species richness and presence of specific taxa were observed in relation to each wind regime and seasons. Taxa which can feature strains with clinical implications were also detected. Data suggested the existence of a main pattern facilitating airborne bacteria dispersion and local scale migration after the dry seasons, which offers a refined interpretive understanding of overall environmental microbiology dynamics.