Sattler, B. University of Innsbruck, Institute of Zoology and Limnology, birgit.sattler@uibk.ac.at
Puxbaum, H. Vienna University of Technology, Institute of Analytical Chemistry, hpuxbaum@fbch.tuwien.ac.at
Limbeck, A. Vienna University of Technology, Institute of Analytical Chemistry, alimbeck@afm02.iac.tuwien.ac.at
Psenner, R. University of Innsbruck, Institute of Zoology and Limnology, roland.psenner@uibk.ac.at

 
MICROBIAL PROCESSES IN CLOUDS
 
Transformation of organic and inorganic material in the atmosphere is assumed to depend on physical and chemical processes in the gas phase and in aerosol particles. Bacteria may act, however, as cloud condensation nuclei and they may be passively transported over large distances. Here we show that bacterial metabolism can play a measurable role in the production and transformation of organic carbon in cloud droplets collected at high altitudes, even at temperatures at or well below 0 C. Although bacterial abundance and biomass in cloud water is low compared to other aquatic environments, growth and carbon production rates per cell are approximately as high as in warm and eutrophic lakes. We consider the atmosphere not only as a conveyor of organisms but as a site where significant microbial processes take place already during transport. Since ca. 60% of the earth surface is covered by clouds, with a still increasing trend, we hypothesize that microorganisms suspended in cloud droplets could play a crucial role in the transformation of airborne organic matter and the chemical composition of snow and rain.
 
Day: Tuesday, Feb. 2
Time: 02:45 - 03:00pm
Location: Sweeney Center
 
Code: SS27TU0245S