Diverse recruitment to a taxonomically structured global atmospheric microbiota

Abstract

Atmospheric transport is critical to dispersal of microorganisms between habitats and this underpins resilience in terrestrial and marine ecosystems globally. A key unresolved question is whether microorganisms assemble to form a taxonomically distinct, geographically variable, and functionally adapted atmospheric microbiota. Here we characterised inter-continental patterns of microbial taxonomic and functional diversity in air within and above the atmospheric boundary layer and in underlying soils for 596 globally sourced samples. Bacterial and fungal assemblages in air were taxonomically structured and deviated significantly from purely stochastic assembly. Patterns differed with location and reflected underlying surface cover and environmental filtering. Source-tracking indicated a complex recruitment process involving local soils plus globally distributed inputs from drylands and the phyllosphere. Assemblages displayed stress-response and metabolic traits relevant to survival in air, and taxonomic and functional diversity were correlated with macroclimate and atmospheric variables. Our findings highlight complexity in the atmospheric microbiota that is key to understanding regional and global ecosystem connectivity.

Seasonal Variation of the Atmospheric Bacterial Community in the Greenlandic High Arctic Is Influenced by Weather Events and Local and Distant Sources

“…Their samples may also have been affected by postdepositional processes, such as selection and cell growth. Contrary, the number of ASVs in the air samples collected in spring and summer in this study closely resembled what had previously been reported in the Arctic ( Cuthbertson et al, 2017 ; Šantl-Temkiv et al, 2018 ; Archer et al, 2021 ). Altogether, our results reflect the pristine nature of the Arctic atmospheric environment, characterized by the dilution and decay during long-range transport, few local sources, as well as scarce human presence and activity which together result in low bacterial diversity and abundance.…”

“…To fully appreciate the processes involved in cloud and ice formation mediated by bioaerosols we must first obtain data on the quantity, diversity, and activity of the aerosolized microorganisms. Recent studies have addressed these questions mostly in temperate regions ( Bowers et al, 2009 ; Temkiv et al, 2012 ; DeLeon-Rodriguez et al, 2013 ; Klein et al, 2016 ; Amato et al, 2017 ; Archer et al, 2021 ). A few studies have investigated these questions in the low and the high Arctic ( Harding et al, 2011 ; Cuthbertson et al, 2017 ; Šantl-Temkiv et al, 2018 ; Tignat-Perrier et al, 2019 ).…”

Active Microbial Airborne Dispersal and Biomorphs as Confounding Factors for Life Detection in the Cell-Degrading Brines of the Polyextreme Dallol Geothermal Field

“…Contamination can also derive from naturally dispersing microbes in aerosols. The atmosphere ensures the connectivity of many ecosystems on Earth by facilitating dispersal even at very long distances ( 27 – 29 ). Intrinsic microbial properties, including size, shape, resistance to desiccation and UV radiation, and even mechanisms to cope with long-term starvation ( 30 ), influence dispersal, but so do local meteorological conditions.…”