• Our new home

    since summer 2021.

  • Hunting for microbes since 2003

  • We seek to understand

    the role of microorganisms in Earth's nutrient cycles

    and as symbionts of other organisms

  • Cycling of carbon, nitrogen and sulfur

    affect the health of our planet

  • The human microbiome -

    Our own social network of microbial friends

  • Ancient invaders -

    Bacterial symbionts of amoebae

    and the evolution of the intracellular lifestyle

  • Marine symbioses:

    Listening in on conversations

    between animals and the microbes they can't live without

  • Single cell techniques offer new insights

    into the ecology of microbes

  • Doctoral School in Microbiology and Environmental Sciences

  • PhD program in Microbial Symbioses

    A special FWF funded track in our doctoral school

Dome News

Latest publications

Both abundant and rare fungi colonizing Fagus sylvatica ectomycorrhizal root-tips shape associated bacterial communities

Ectomycorrhizal fungi live in close association with their host plants and form complex interactions with bacterial/archaeal communities in soil. We investigated whether abundant or rare ectomycorrhizal fungi on root-tips of young beech trees (Fagus sylvatica) shape bacterial/archaeal communities. We sequenced 16S rRNA genes and fungal internal transcribed spacer regions of individual root-tips and used ecological networks to detect the tendency of certain assemblies of fungal and bacterial/archaeal taxa to inhabit the same root-tip (i.e. modularity). Individual ectomycorrhizal root-tips hosted distinct fungal communities associated with unique bacterial/archaeal communities. The structure of the fungal-bacterial/archaeal association was determined by both, dominant and rare fungi. Integrating our data in a conceptual framework suggests that the effect of rare fungi on the bacterial/archaeal communities of ectomycorrhizal root-tips contributes to assemblages of bacteria/archaea on root-tips. This highlights the potential impact of complex fine-scale interactions between root-tip associated fungi and other soil microorganisms for the ectomycorrhizal symbiosis.

Dietrich M, Montesinos-Navarro A, Gabriel R, Strasser F, Meier DV, Mayerhofer W, Gorka S, Wiesenbauer J, Martin V, Weidinger M, Richter A, Kaiser C, Woebken D
2022 - Commun Biol, 5: 1261

How to Verify Non-Presence—The Challenge of Axenic Algae Cultivation

Many phycological applications require the growth and maintenance of pure algae cultures. In some research areas, such as biochemistry and physiology, axenic growth is essential to avoid misinterpretations caused by contaminants. Nonetheless, axenicity—defined as the state of only a single strain being present, free of any other organism—needs to be verified. We compare the available methods to assess axenicity. We first purified unialgal Limnospira fusiformis cultures with an established series of axenicity treatments, and by including two additional treatment steps. The presumable axenic cultures were then tested for their axenic state by applying conventional tests on LB (lysogeny broth) agar-plates, 16S rRNA gene amplicon sequencing, flow-cytometry and epifluorescence microscopy. Only the plate tests indicated axenic conditions. We found a linear relationship between total cell counts of contaminants achieved by flow cytometry and epifluorescence microscopy, with flow cytometry counts being consistently higher. In addition, 16S rRNA gene amplicon sequencing demonstrated its superiority by not only being an efficient tool for axenicity testing, but also for identification of persistent contaminants. Although classic plate tests are still commonly used to verify axenicity, we found the LB-agar-plate technique to be inappropriate. Cultivation-independent methods are highly recommended to test for axenic conditions. A combination of flow-cytometry and 16S rRNA gene amplicon sequencing complement each other and will yield the most reliable result.

Pokorny L, Hausmann B, Pjevac P, Schagerl M
2022 - Cells, in press

Disturbances in microbial skin recolonization and cutaneous immune response following allogeneic stem cell transfer

The composition of the gut microbiome influences the clinical course after allogeneic hematopoietic stem cell transplantation (HSCT), but little is known about the relevance of skin microorganisms. In a single-center, observational study, we recruited a cohort of 50 patients before undergoing conditioning treatment and took both stool and skin samples up to one year after HSCT. We could confirm intestinal dysbiosis following HSCT and report that the skin microbiome is likewise perturbed in HSCT-recipients. Overall bacterial colonization of the skin was decreased after conditioning. Particularly patients that developed acute skin graft-versus-host disease (aGVHD) presented with an overabundance of Staphylococcus spp. In addition, a loss in alpha diversity was indicative of aGVHD development already before disease onset and correlated with disease severity. Further, co-localization of CD45+ leukocytes and staphylococci was observed in the skin of aGVHD patients even before disease development and paralleled with upregulated genes required for antigen-presentation in mononuclear phagocytes. Overall, our data reveal disturbances of the skin microbiome as well as cutaneous immune response in HSCT recipients with changes associated with cutaneous aGVHD.

Bayer N, Hausman B, Pandey RV, Deckert F, Gail LM, Strobl J, Pjevac P, Krall C, Unterluggauer L, Redl A, Bachmayr V, Kleissl L, Nehr M, Kirkegaard R, Makrisathis A, Watzenboeck ML, Nica R, Staud C, Hammerl L, Wohlfarth P, Ecker RC, Knapp S, Rabitsch W, Berry D, Stary G
2022 - Leukemia, in press

Lecture series

DOME Lecture: "Recycling versus loss: the pivotal role of nitrite in the marine nitrogen cycle"

Laura Bristow
Assistant Professor for Marine Sciences, University of Gothenburg, Sweden
17.11.2022
12:00 h
hybrid, UBB HS 1

DOME Lecture: "Microbial processing of dissolved and particulate organic matter in the mesopelagic ocean"

Alyson Santoro
Assoc. Prof. in Ecology, Evolution and Marine Biology, University of California Santa Barbara, USA
27.10.2022
12:00 h
hybrid, UBB HS 1

DOME Lecture: “'Dark oxygen' - an electron acceptor for productive and diverse microbial communities in ancient groundwaters"

Emil Ruff
Marine Biological Laboratory, Massachusetts, USA
15.06.2022
12:00 h
hybrid, UBB HS 2