High diversity of fungi in air particulate matter

Abstract

Fungal spores can account for large proportions of air particulate matter, and they may potentially influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog, and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, not well-known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse fraction and more human pathogens and allergens in the respirable fine particle fraction (<3 m). Moreover, the ratio of Basidiomycota to Ascomycota was found to be much higher than previously assumed, which might also apply to the biosphere.atmospheric aerosol ͉ bioaerosol ͉ DNA analysis ͉ fungal spores R ecent studies have shown that fungal spores and other biological particles can account for large proportions of aerosol particle mass in pristine rainforest air as well as in rural and urban environments (1-5). For example, fungal spores were found to account for up to 45% of coarse particle mass (Ͼ1 m) in tropical rainforest air and up to 4-11% of fine particle mass (Յ2.5 m) in urban and rural air (3). Fungi have also been found in clouds, fog, and precipitation where these and other biological particles can act as nuclei for water droplets and ice crystals and can influence precipitation patterns and the Earth's energy budget (e.g., refs. 6-17). On average, the number and mass concentrations of fungal spores in continental boundary layer air are on the order of 10 3 -10 4 m Ϫ3 and approximately 1 g m Ϫ3 , respectively, and the estimated global emissions of approximately 50 Tg yr Ϫ1 are among the largest sources of organic aerosol (1).Some fungi are major pathogens or allergens for humans, animals, and plants, and air is the primary medium for their dispersal (18)(19)(20), but the diversity of fungi in air particulate matter is not well-known. The traditional cultivation, microscopy, and chemical tracer techniques applied in earlier studies were insufficient for a broad coverage of different fungal species, and recently reported first applications of molecular genetic techniques were very limited in scope and methodology as discussed below.In this study, we investigated and characterized the diversity and frequency of occurrence of fungi in air particulate matter by DNA extraction and sequence analysis of the internal transcribed spacer region (ITS).

Identifying airborne fungi in Seoul, Korea using metagenomics

“…We utilize LSU sequences and identify more than 1,200 OTUs in 103 genera (Table 2). This trend of uncovering greater species diversity has been seen in other aerial fungal studies across the globe (Ebner et al, 1989;Fernández et al, 1998;Gioulekas et al, 2004;Wu et al, 2004Wu et al, , 2007Fang et al, 2005;Fröhlich-Nowoisky et al, 2009). We predict with longer reads and more refined databases, identification of fungal taxa will become more accurate and resolution will reach the species/ strain level, and an even greater fungal diversity will be realized in the future.…”

“…Most of these studies depended on spore morphology and/or culture dependent methods for identification. As a majority of fungi are not readily cultured (Pace, 1997;Rappé and Giovannoni, 2003;Fröhlich-Nowoisky et al, 2009) or easily identified by spores alone (Burge, 1985), these results are expected to be an underestimation of airborne fungal diversity (Wu et al, 2004). Metagenomics, a new field in biology, uses new DNA sequencing technologies (e.g., pyrosequencing) to directly sequence and identify environmental microbes (Riesenfeld et al, 2004).…”

A novel pathway of direct methane production and emission by eukaryotes including plants, animals and fungi: An overview

“…This pathway involved a substratedependent process that suggested that a common CH 4 production pathway exists in all fungal species employed by the authors. An intriguing observation was made by Watanabe et al (2012), who demonstrated slight increases in CH 4 concentrations in blank vials during incubation, which could be explained by airborne fungi (Frohlich-Nowoisky et al, 2009). …”

Temporal variability and effect of environmental variables on airborne bacterial communities in an urban area of Northern Italy

“…As a result, the number of studies which have applied culture-independent techniques to the study of airborne bacteria is still limited. For example, such methods were used to assess the diversity of bacteria associated with small-sized particles during dust events (Polymenakou et al 2008) and to characterise the spatial and temporal variations of bioaerosols in different geographical localities and/or different land uses (Angenent et al 2005;Bowers et al 2009Bowers et al , 2010Bowers et al , 2011Brodie et al 2007;Franzetti et al 2010;Frohlich-Nowoisky et al 2009). However, the potential of culture-independent molecular methods, such as quantitative PCR (qPCR), rRNA gene sequencing and hybridisation (i.e.…”