Screening and characterization of biological ice nuclei and their influence on the ice nucleation activity of soil and mineral dust.

• Applicant: Dr. Janine Fröhlich
• Subject Area: Atmospheric Science
• Term: from 2011 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 170852269

Microorganisms are ubiquitous in soil, cryptogamic covers, and in the atmosphere. Several bacterial, fungal, lichen, and pollen species have been identified as ice nucleating particles (INP) that can initiate the formation of ice at relatively high temperatures and biological residues in soil dust are a potentially strong source of atmospheric INP. However, the sources of biological INP produced and released from plants, soil and cryptogamic covers remain unclear, even though their potential role in triggering glaciation and precipitation has recently been supported. Recent studies of various soil and air samples indicate that diverse ice nucleating (IN) fungi from more than one phylum are not only present in air and soil but can also be abundant components of the cultivable community. Thus, the proposed project is aimed at identifying unknown IN microorganisms and materials from soils, plants, and cryptogamic covers and on the investigation of their influence on the IN activity of soil dust. The necessary techniques for a screening of multiple cultures of e.g. cyanobacteria are well established in our laboratory. In the proposed project the INP of the new identified IN organisms should also be characterized on a molecular level.

• DFG Programme: Research Units
• Subproject of: FOR 1525: INUIT - Ice Nuclei Research Unit
• Co-Investigator: Professor Dr. Ulrich Pöschl