Atmospheric microbiome in Israel, Eastern Mediterranean

Processes influencing the atmospheric transport of airborne bacterial communities are poorly understood. Here, we report quantitative evidence of the key factors influencing the atmospheric transport of airborne bacterial communities sampled in Israel, Eastern Mediterranean. We extracted DNA and RNA from size-resolved aerosols sampled from air masses of different origins, followed by qPCR and high-throughput amplicon sequencing of 16S ribosomal RNA gene and transcripts. We find airborne bacterial community composition varied with air mass origin and particle size. Bacterial abundance, alpha diversity and species richness were higher in terrestrially-influenced air masses than marine-influenced air masses, and were also high in the coarse particle fraction (3.0 to 10.0 µm) than the fine fraction (0.49 to 1.5 µm). This suggests airborne bacteria were mostly associated with mineral dust or transported as cell aggregates. High abundances of rRNA from human, animal and plant pathogen taxa indicate potential ecological impacts of atmospheric bacterial transport.