Microbial ecology of the atmosphere

Este artículo contiene 18 páginas, 7 figuras.
The atmosphere connects habitats across multiple spatial scales via airborne dispersal of microbial cells, propagules and biomolecules. Atmospheric microorganisms have been implicated in a variety of biochemical and biophysical transformations. Here, we review ecological aspects of airborne microorganisms with respect to their dispersal, activity and contribution to climatic processes. Latest studies utilizing metagenomic approaches demonstrate that airborne microbial communities exhibit pronounced biogeography, driven by a combination of biotic and abiotic factors. We quantify distributions and fluxes of microbial cells between surface habitats and the atmosphere and place special emphasis on long-range pathogen dispersal. Recent advances have established that these processes may be relevant for macroecological outcomes in terrestrial and marine habitats. We evaluate the potential biological transformation of atmospheric volatile organic compounds and other substrates by airborne microorganisms and discuss clouds as hotspots of microbial metabolic activity in the atmosphere. Furthermore, we emphasize the role of microorganisms as ice nucleating particles and their relevance for the water cycle via formation of clouds and precipitation. Finally, potential impacts of anthropogenic forcing on the natural atmospheric microbiota via emission of particulate matter, greenhouse gases and microorganisms are discussed.
This work was supported by the following research grants: TST was supported by the Danish National Research Foundation [grant number DNRF106], the Aarhus University Research Foundation Nova programme [grant number AUFF-E-2015-FLS- 9-10], the Villum Foundation [grant numbers 23175 and 37435], the NOVO Interdisciplinary Synergy Programme [grant number NNF19OC0056963] and the Independent Research Fund Denmark [grant number 9145-00001B]. PA was supported by the French National Research Agency Make Our Planet Great Again (MOPGA) programme [grant number ANR-17-MOPGA-0013]. EOC was supported by the Spanish State Research Agency [grant number AEI- MICINN] and European Regional Development Fund [grant number INTERACTOMA RTI2018-101205-B-I00]. PKHL was supported by the Environment Conservation Fund of theGovernment of Hong Kong [grant number 2019–12]. SBP was supported by the Ministry of Education - SingaporeandYale-NUS College [grant number R-607-265-331-121].