Microbial functional signature in the atmospheric boundary layer

Abstract

Abstract. Microorganisms are ubiquitous in the atmosphere, and some airborne microbial cells were shown to be particularly resistant to atmospheric physical and chemical conditions (e.g., ultraviolet – UV – radiation, desiccation and the presence of radicals). In addition to surviving, some cultivable microorganisms of airborne origin were shown to be able to grow on atmospheric chemicals in laboratory experiments. Metagenomic investigations have been used to identify specific signatures of microbial functional potential in different ecosystems. We conducted a comparative metagenomic study on the overall microbial functional potential and specific metabolic and stress-related microbial functions of atmospheric microorganisms in order to determine whether airborne microbial communities possess an atmosphere-specific functional potential signature as compared to other ecosystems (i.e., soil, sediment, snow, feces, surface seawater etc.). In the absence of a specific atmospheric signature, the atmospheric samples collected at nine sites around the world were similar to their underlying ecosystems. In addition, atmospheric samples were characterized by a relatively high proportion of fungi. The higher proportion of sequences annotated as genes involved in stress-related functions (i.e., functions related to the response to desiccation, UV radiation, oxidative stress etc.) resulted in part from the high concentrations of fungi that might resist and survive atmospheric physical stress better than bacteria.

Functional Genes Profile of Atmospheric Dust in the East Mediterranean Suggests Widespread Anthropogenic Influence on Aerobiome Composition

“…Genes associated with benzoate, xylene, and atrazine degradation were significantly more abundant in Dust_IL than in all other examined data sets. We did not find a similar comparison made by any other metagenomic studies of atmospheric samples (Aalismail et al, 2019;Amato et al, 2019;Be et al, 2014;Cao et al, 2014;Tignat-Perrier, Dommergue, Thollot, Magand, Vogel, et al, 2020;Tringe et al, 2008;Yooseph et al, 2013), with the exception of Yooseph et al ( 2013) that found some abundance of genes associated with xenobiotic biodegradation in air samples from urban aerosols. Some differentially abundant genes were found on bacterial plasmids, rendering them eligible for horizontal gene transfer (Leahy & Colwell, 1990;Perkins et al, 1990).…”

“…Another environment that exhibited similarity to Dust_IL was local soil, as was shown previously in numerous studies sampling aerosols from different environments (Cao et al, 2014;Gat et al, 2017;Mazar et al, 2016;Tignat-Perrier, Dommergue, Thollot, Magand, Vogel, et al, 2020). The soils selected for comparison in this study were desert crusts from the Israeli Negev desert (Negev_soil) and various soils from different sites in Israel (IL_ soils).…”

“…The studies provided preliminary insights into the aerobiome's potential functions. Both studies by Aalismail et al (2019) and Tignat-Perrier, Dommergue, Thollot, Magand, Vogel, et al (2020) attempted to determine the potential survival of airborne microorganisms by looking at the abundance of specific functional genes that would render microorganisms adapted to atmospheric transport; these functions included resistance to UV radiation, oxidative stress, and sporulation. These genes were found in all air samples described in these studies yet were not always significantly more abundant in the aerobiome than in other microbiomes (Tignat-Perrier, Dommergue, Thollot, Magand, Vogel, et al, 2020).…”

Size-Resolved Community Structure of Bacteria and Fungi Transported by Dust in the Middle East

“…The composition of the aerobiome can affect human and ecosystem health ( Aylor et al, 2011 ; Lang-Yona et al, 2012 , 2014 ; Rahav et al, 2016 ) and has, therefore, been the focus of numerous studies in the field of atmospheric sciences (e.g., Tong and Lighthart, 2000 ; Gonzalez-Martin et al, 2014 ; Du et al, 2018 ; Maki et al, 2019 ; Mhuireach et al, 2019 ; Tignat-Perrier et al, 2020 ). The aerobiome is comprised of a dynamic, complex assembly of microorganisms, affected by a myriad of atmospheric, geographic and other parameters.…”

Table_2.DOCX

“…The composition of the aerobiome can affect human and ecosystem health (Aylor et al, 2011;Lang-Yona et al, 2012, 2014Rahav et al, 2016) and has, therefore, been the focus of numerous studies in the field of atmospheric sciences (e.g., Tong and Lighthart, 2000;Gonzalez-Martin et al, 2014;Du et al, 2018;Maki et al, 2019;Mhuireach et al, 2019;Tignat-Perrier et al, 2020). The aerobiome is comprised of a dynamic, complex assembly of microorganisms, affected by a myriad of atmospheric, geographic and other parameters.…”