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Abstract

The airborne microbiome, that is the totality of microbes in the atmosphere
as a defined environment, influences a broad range of processes that have positive
or negative consequences for the atmosphere and/or biosphere. Patterns of
archaea and bacteria diversity in the atmosphere are likely caused by the spatial
and temporal variation of emission sources and also influenced by a wide
range of environmental and meteorological factors, e.g. radiation, precipitation
events or rapid changes in temperatures. The overall diversity of the microbiome
is not only driven by nature but additionally by many anthropogenic
influences. Studies of all these phenomena are still in their infancy, especially
research on the overall airborne microbiome lacks until today. In this thesis
the presence, diversity and properties of archaea, bacteria and fungi as part
of the airborne microbiome, were revealed by using DNA based sequencing
approaches. Mainz, Germany, was chosen as an example site for continental
boundary layer air. Taken together, the findings show a higher diversity and
relative abundance for bacteria compared to archaea. Additionally, the size
fraction influenced the bacterial diversity significantly as the species richness
in bioaerosols larger than 3 m was found to be higher by more than 25 % than
the fine fraction, which is dominated by spore-forming taxa. The results also
point to the diverse effects of natural as well as anthropogenic influences on
the diversity of the microbiome of the atmosphere, e.g. fertilization with live
stock manure or biogas substrates that affect the diversity of archaea. This
thesis may be seen as the first attempt to collate research on different groups
of organisms for one specific sampling location to get insights into the entire
airborne microbiome.