Aerosol measurement methods to quantify spore emissions from fungi and cryptogamic covers in the Amazon

Abstract

Bioaerosols are considered to play a relevant role in atmospheric processes, but their sources, properties and spatiotemporal distribution in the atmosphere are not yet well characterized. In the Amazon Basin, primary biological aerosol particles (PBAP) account for a large fraction of coarse particulate matter, and fungal spores are among the most abundant PBAP there as well as in other vegetated continental regions. Furthermore, PBAP could also be important ice nuclei in Amazonia. Measurement data on the release of fungal spores under natural conditions, however, are sparse. Here we present 5 an experimental approach to analyze and quantify the spore release from fungi and other spore producing organisms under natural and laboratory conditions. For measurements under natural conditions, the samples were kept in their natural environment and a setup was developed to estimate the spore release numbers and sizes together with the microclimatic factors temperature and air humidity, as well as the mesoclimatic parameters net radiation, rain, and fog occurrence. For experiments in the laboratory, we developed a cuvette to assess the particle size and number of newly released fungal spores under 10 controlled conditions, simultaneously measuring temperature and relative humidity inside the cuvette. Both approaches were combined with bioaerosol sampling techniques to characterize the released particles by microscopic methods. For fruiting bodies of the basidiomycetous species, Rigidoporus microporus, the model species for which these techniques were tested, the highest frequency of spore release occurred in the range of 62 and 96 % relative humidity. The results obtained for this model species reveal characteristic spore release patterns linked to environmental or experimental conditions, indicating that the 15 moisture status of the sample may be a regulating factor, while temperature and light seem to play a minor role for this species.The presented approach enables systematic studies aimed at the quantification and validation of spore emission rates and inventories, which can be applied to a regional mapping of cryptogamic organisms under given environmental conditions. 1 of bioaerosol emissions, which is roughly 23 % of total primary organic aerosol emission (Fröhlich-Nowoisky et al., 2016; Graham et al., 2003; Heald and Spracklen, 2009; Jacobson and Streets, 2009;Sesartic et al., 2013).Species of Polyporales (Basidiomycota), the order of the model species of the present study, mostly colonize dead wood, 30where they form vegetative hyphae degrading the wood. On the surface of dead wood they form fruiting bodies with pores located at their lower side. The surface of these pores is covered by a hymenium, where basidiospores are produced on basidia.Each basidium externally forms mostly four asymmetrical basidiospores on little curved, tapering stalks, called sterigmata.The spores are fixed to the sterigmata at the hilum, which thus forms a characteristic feature of basidiospores.

Empirical formulation for multiple groups of primary biological ice nucleating particles from field observations over Amazonia

“…Fungal spores and associated fragments (group 1) were one of the most common classes of bioaerosols observed during the campaign. Fungi can grow in almost every ecosystem and are efficient in aerosolization (Adhikari et al, 2009;Löbs et al 2020). The morphological characteristics of fungal spores have been well documented in global air and are summarized in Table 3 (Després et al 2012 and references therein;Shi et al 2003;Tamer Vestlund et al 2014;Valsan et al 2015;Valsan et al 2016;Priyamvada et al 2017;Wu et al 2019, Li et al 2020.…”

Air pollution and its impact on the concentration of airborne fungi in the megacity of São Paulo, Brazil

“…Different sampling methods for bioaerosols can be found in literature. Nowadays, the impactation method is the most used and the one selected for the present study ( Flores et al., 2014 ; Moura et al., 2015 ; Löbs et al., 2020 ; Emygdio et al., 2018a , Emygdio et al., 2018b ). With a large air volume forced through an impactor equipment, the air flow is uniformized along filter pores and the suspended material fixed on a plate surface ( Khan and Karuppayil, 2012 ; Haas et al., 2017 ; Gniadek et al., 2017 ).…”

Supplementary material to "Bioaerosols in the Amazon rain forest: Temporal variations and vertical profiles of Eukarya, Bacteria and Archaea"

“…Consequently, there are manifold potential bioaerosol sources including water and soil surfaces, animals, plants, microbial surface communities, and decaying biomaterial. (Artaxo et al, 1990;Löbs et al, 2020;Fröhlich-Nowoisky et al, 2016). Their emission can be effected by means of active processes (e.g.…”