• 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

  • Ancient invaders -

    Bacterial symbionts of amoebae

    and the evolution of the intracellular lifestyle

  • The human microbiome -

    Our own social network of microbial friends

  • Single cell techniques offer new insights

    into the ecology of microbes

  • Apply for the DOME International PhD/PostDoc program

Dome News

Latest publications

Relative abundance of Nitrotoga in a biofilter of a cold freshwater aquaculture plant appears to be stimulated by a slightly acidic pH-value

Functioning of recirculation aquaculture systems (RAS) is essential to maintain water quality for fish health and one crucial process here is nitrification. The investigated RAS was connected to a rainbow trout production system and operated at an average temperature of 13°C and pH 6.8. Community analyses of the nitrifying biofilm revealed a coexistence of Nitrospira and Nitrotoga and it is hypothesized that a slightly acidic pH in combination with lower temperatures favors growth of the latter. Modification of the standard cultivation approach towards lowered pH-values of 5.7 to 6.0 resulted in the successful enrichment (99% purity) of Nitrotoga sp. HW29, which had a 16S rRNA sequence similarity of 99.0% to Nitrotoga arctica. Reference cultures of Nitrospira defluvii and the novel Nitrotoga sp. HW29 were used to confirm differentiation of these species in distinct ecological niches. Nitrotoga sp. HW29 revealed pH and temperature optima of 6.8 and at 22°C, respectively, whereas Nitrospira defluvii displayed the highest nitrite oxidation rate at pH 7.3 and 32°C. To our knowledge, this is the first report about the occurrence of Nitrotoga as main NOB in freshwater aquaculture systems and indicates that a slightly acidic pH in addition to temperatures below 20°C can be applied as selective isolation criterion for this microorganism.

Hüpeden J, Wegen S, Off S, Lücker S, Bedarf Y, Daims H, Kühn C, Spieck E
2016 - Appl. Environ. Microbiol., in press

Back to the future of soil metagenomics

Nesme J, Achouak W, Agathos SN, Bailey M, Baldrian P, Brunel D, Frostegård A, Heulin T, Jansson JK, Jurkevitch E, Kruus KL, Kowalchuk GA, Lagares A, Lappin-Scott HM, Lemanceau P, Le Paslier D, Mandic-Mulec I, Murrell JC, Myrold DD, Nalin R, Nannipieri P, Neufeld JD, O’Gara F, Parnell JJ, Pühler A, Pylro V, Ramos JL, Roesch LFW, Schloter M, Schleper C, Sczyrba A, Sessitsch A, Sjöling S, Sørensen J, Sørensen SJ, Tebbe CC, Topp E, Tsiamis G, van Elsas JD, Keulen G, Widmer F, Wagner M, Zhang T, Zhang X, Zhao L, Zhu Y-G, Vogel TM, Simonet P
2016 - Front Microbiol, in press

Trophosome of the deep-sea tubeworm Riftia pachyptila inhibits bacterial growth

The giant tubeworm Riftia pachyptila lives in symbiosis with the chemoautotrophic gammaproteobacterium Cand. Endoriftia persephone. Symbionts are released back into the environment upon host death in high-pressure experiments, while microbial fouling is not involved in trophosome degradation. Therefore, we examined the antimicrobial effect of the tubeworm's trophosome and skin. The growth of all four tested Gram-positive, but only of one of the tested Gram-negative bacterial strains was inhibited by freshly fixed and degrading trophosome (incubated up to ten days at either warm or cold temperature), while no effect on Saccharomyces cerevisiae was observed. The skin did not show antimicrobial effects. A liquid chromatography-mass spectrometric analysis of the ethanol supernatant of fixed trophosomes lead to the tentative identification of the phospholipids 1-palmitoleyl-2-lyso-phosphatidylethanolamine, 2-palmitoleyl-1-lyso-phosphatidylethanolamine and the free fatty acids palmitoleic, palmitic and oleic acid, which are known to have an antimicrobial effect. As a result of tissue autolysis, the abundance of the free fatty acids increased with longer incubation time of trophosome samples. This correlated with an increasing growth inhibition of Bacillus subtilis and Listeria welshimeri, but not of the other bacterial strains. Therefore, the free fatty acids produced upon host degradation could be the cause of inhibition of at least these two bacterial strains.

Klose J, Aistleitner K, Horn M, Krenn L, Dirsch V, Zehl M, Bright M
2016 - PLoS One, 11: e0146446

Lecture series

Importance of chemosymbiotic lucinid bivalves in seagrass community functioning

Matthijs van der Geest
Université de Montpellier
20.01.2016
11:00 h
Seminar room DoME (2.309), UZA 1

The contribution of phage-mediated gene transfer to microbial genome evolution

Tal Dagan
Christian-Albrechts-Universität zu Kiel
23.10.2015
13:30 h
Seminar room DoME (2.309)

Cool microbes: Assessing the role of acidobacteria communities in carbon and nitrogen cycling processes in arctic tundra soils

Max Häggblom
Department of Biochemistry and Microbiology School of Environmental and Biological Sciences Rutgers, The State University of New Jersey
11.09.2015
11:00 h
Seminar Room DOME (2.309)