Articles | Volume 11, issue 21
Biogeosciences, 11, 6067–6079, 2014
Biogeosciences, 11, 6067–6079, 2014

Research article 11 Nov 2014

Research article | 11 Nov 2014

Diversity and seasonal dynamics of airborne archaea

J. Fröhlich-Nowoisky1, C. Ruzene Nespoli1, D. A. Pickersgill1,2, P. E. Galand3,4, I. Müller-Germann1,5, T. Nunes6, J. Gomes Cardoso6,7, S. M. Almeida8, C. Pio6, M. O. Andreae1, R. Conrad9, U. Pöschl1, and V. R. Després2 J. Fröhlich-Nowoisky et al.
  • 1Max Planck Institute for Chemistry, P.O. Box 3060, 55020 Mainz, Germany
  • 2Institute of General Botany, Johannes Gutenberg University, Johannes-von-Müller-Weg 6, 55128 Mainz, Germany
  • 3UPMC, Univ Paris 06, Observatoire Océanologique, Banyuls-sur-Mer, France
  • 4CNRS, UMR8222, Laboratoire d'écogéochimie des environnements benthiques, Observatoire Océanologique, Banyuls-sur-Mer, France
  • 5Geosciences, Johannes Gutenberg University, Joh.-Joachim-Becher-Weg 21, 55128 Mainz, Germany
  • 6CESAM & Department of Environment, University of Aveiro, 3810-193 Aveiro, Portugal
  • 7University of Cape Verde, 279 CPraia, Santiago, Cape Verde
  • 8C2TN, Instituto Superior Técnico, Universidade de Lisboa, EN10, 139.7 km, 2695-066 Bobadela LRS, Portugal
  • 9Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, 35043 Marburg, Germany

Abstract. Archaea are widespread and abundant in many terrestrial and aquatic environments, and are thus outside extreme environments, accounting for up to ~10% of the prokaryotes. Compared to bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of archaea in the atmosphere. By means of DNA analysis and Sanger sequencing targeting the 16S rRNA (435 sequences) and amoA genes in samples of air particulate matter collected over 1 year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne archaea. The detected archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase in bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly predicted methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands (72 sequences) and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role in the dispersal of archaea, including assumed ammonia-oxidizing Thaumarchaeota and methanogens.

Short summary
We have investigated the presence of archaea as well as their amoA gene diversity in aerosol particles collected over 1 year in central Europe and found that, within the 16S and amoA gene, Thaumarchaeota prevail and experience a diversity peak in fall, while only few Euryarchaeota were detected primarily in spring. We also compared the results with airborne archaea from Cape Verde and observe that the proportions of Euryarchaeota seem to be enhanced in coastal air compared to continental air.
Final-revised paper