Community composition and seasonal changes of archaea in coarse and fine air particulate matter

Abstract

Abstract. Archaea are ubiquitous in terrestrial and marine environments and play an important role in biogeochemical cycles. Although air acts as the primary medium for their dispersal among different habitats, their diversity and abundance is not well characterized. The main reason for this lack of insight is that archaea are difficult to culture, seem to be low in number in the atmosphere, and have so far been difficult to detect even with molecular genetic approaches. However, to better understand the transport, residence time, and living conditions of microorganisms in the atmosphere as well as their effects on the atmosphere and vice versa, it is essential to study all groups of bioaerosols. Here we present an in-depth analysis of airborne archaea based on Illumina sequencing of 16S rRNA genes from atmospheric coarse and fine particulate matter samples and show seasonal dynamics and discuss anthropogenic influences on the diversity, composition, and abundance of airborne archaea.The relative proportions of archaea to bacteria, the differences of the community composition in fine and coarse particulate matter, and the high abundance in coarse matter of one typical soil related family, the Nitrososphaeraceae, point to local phyllosphere and soil habitats as primary emission sources of airborne archaea.We found comparable seasonal dynamics for the dominating Euryarchaeota classes and Crenarchaeota orders peaking in summer and fall. In contrast, the omnipresent Cenarchaeales and the Thermoplasmata occur only throughout summer and fall. We also gained novel insights into archaeal composition in fine particulate matter (< 3 µm), with Cenarchaeaceae, Nitrososphaeraceae, Methanosarcinales, Thermoplasmata, and the genus Nitrosopumilus as the dominating taxa.The seasonal dynamics of methanogenic Euryarchaeota point to anthropogenic activities, such as fertilization of agricultural fields with biogas substrates or manure, as sources of airborne archaea. This study gains a deeper insight into the abundance and composition of archaea in the atmosphere, especially within the fine particle mode, which adds to a better understanding of the overall atmospheric microbiome.

Assessing Microbial Community Patterns During Incipient Soil Formation From Basalt

“…Although the miniLEO system overall does not appear to be conducive for either of these environments (low pH and anaerobic conditions), the gradual increase in Thermoplasmata (from 2.6% in the surficial sample to 11.9% in Depth_70 samples) is suggestive of pockets of microenvironments for such metabolisms to thrive and/or likelihood of organisms with novel metabolic strategies. Additionally, the absence of Euryarcheota in the parent material and irrigation water suggests that air is most likely the source, as highlighted in a recent study (Wehking et al, ), which shows Euryarcheota as a dominant airborne archaea in the fine particulate matter. Overall, our study revealed a highly diverse bacterial population and comparatively less diverse archaeal population in the incipient terrestrial basalt soil system subjected to enhanced weathering processes.…”

Microbial Flow Within an Air-Phyllosphere-Soil Continuum

“…At the phylum level, the archaea Crenarchaeota was sharply lower (<1%) in the phyllosphere but higher in both air and soil samples, which concurred with the previous study ( Vorholt, 2012 ). The shared of Crenarchaeota within air, phyllosphere, and soil suggested that soil may be a possible source of archaea affecting adjacent air ( Wehking et al, 2018 ). Previous studies have found that the bacterial families of Rhizobiaceae and Pseudomonadaceae are commonly observed in plants, which would help create differences in composition of the phyllosphere, air, and soil samples ( Yanni et al, 1997 ; Hunter et al, 2010 ).…”

The Biogeography of Dust in the Eastern Mediterranean

“…19,64,68 Variations over seasons and in airmass origin were also linked to changes in aerosol microbial community composition. 1,2,6,9,69,70 The aerobiome community composition displays mixtures of sources, and detecting a constant and stable indigenous microbial community was not yet reported. As such, the identi ed microorganisms may serve as tracers for the sources contributing to the aerobiome.…”