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Projekte

Environmental Mycology

MICINSNOW – Microbial Interactions in Snow-Covered Habitats

Snow-covered landscapes suggest an image of dormancy and hibernation. However, underneath the snow cover soil is teeming with microbial activity. The project “MICINSNOW - Microbial Interactions in Snow Covered Habitats” investigates how winter-active soil microbial communities (MCs) interact with each other.

MCs are investigated at three different habitat types, ranging from recently de-glaciated bare-soil in the glacier forefield, over alpine dwarf shrub communities with about 150 years of soil development, to a Swiss stone pine forest with a distinct humus layer. The hypotheses to test are: 1) Snow-covered soil harbours typical winter MCs. 2) There are typical associations between winter-active fungi and prokaryotic microorganisms (bacteria, archaea), which co-occur due to mutual dependencies. 3) Fungi dominate winter-active MCs and a large proportion of them are currently unknown.

To test these hypotheses, the total of microbial organisms is captured by massive parallel sequencing of soil DNA and RNA, which enables us to simultaneously get information about the identity and activity of the present soil microorganisms. Bioinformatics and statistical analyses deliver first conclusions on microbial interactions, which will be tested in a second step by visual methods (FISH: fluorescence in situ hybridization). To selectively isolate winter-active fungi by a cultivation-dependent approach, in-growth mesh bags filled with sterile quartz sand are buried in the soil. Fungi that are active during the time of burial will grow through the bags and leave biomass on the quartz sand. Fungal isolates can then be obtained by incubation of sand grains on nutrient media. Pure cultures are classified based on morphological characteristics and unambiguously identified by marker genes.

Previously unknown isolates are characterized with comparative morphological, physiological, and phylogenetic methods and described as new species. All isolates will be deposited in public microbial culture collections and thus made available to the scientific community for further studies (e.g. screening for cold-adapted enzymes). What makes this project particularly innovative and valuable is that interactions of active soil MCs are investigated based a combination of cultivation, culture-independent molecular methods, visual methods and modern bioinformatics tools. The knowledge on typical interactions between microorganisms provides insights in the potential role of microbial associations in cold soil, and sets the stage for further experimental studies on the function of fungi and prokaryotic organisms in snow-covered soils.

Project Partners:

Dr. Beat Frey, Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft (WSL) Brimersdorf (CH)

Dr. Benedetta Turchetti, Ciro Sannino, Pietro Buzzini, Microbiology research Unit of the Department of Agricultural, Food and Environmental Sciences of the University of Perugia (Italy)

 

  P31038_BBL (FWF)