• 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

Genus Candidatus Nitrosotenuis

Candidatus Nitrosotenuis is a genus of Thaumarchaeota that can be found widely distributed in soils, freshwater, hot springs, the subsurface, and activated sludge. They may be rods or spheres and may or may not have flagella. Like other known and described Thaumarchaeota, Ca. Nitrosotenuis are aerobic chemolithautotrophs that use energy gained from the oxidation of ammonia to nitrite to fix carbon via modified 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway. At this time, no pure culture of Ca. Nitrosotenuis exists, but some of the six available enrichments with members of the genus are almost pure. It remains to be  demonstrated whether the remaining bacterial contaminants provide essential compounds to Ca. Nitrosotenuis. Enrichments of Ca. Nitrosotenuis are intolerant to high salinity (>0.3%), although they are phylogenetically related to the Group I.1a Thaumarchaeota (Nitrosopumilaceae), which includes taxa that are widely distributed in the ocean.

  1.  

Herbold CW, Lebedeva E, Palatinszky M, Wagner M
2016 - In press. in Bergey’s Manual of Systematics of Archaea and Bacteria. (William B. Whitman). John Wiley & Sons, Chichester, England

A new perspective on microbes formerly known as nitrite-oxidizing bacteria

Nitrite-oxidizing bacteria (NOB) catalyze the second step of nitrification, nitrite oxidation to nitrate, which is an important process of the biogeochemical nitrogen cycle. NOB were traditionally perceived as physiologically restricted organisms and were less intensively studied than other nitrogen-cycling microorganisms. This picture is contrasted by new discoveries of an unexpected high diversity of mostly uncultured NOB and a great physiological versatility, which includes complex microbe-microbe interactions and lifestyles outside the nitrogen cycle. Most surprisingly, close relatives to NOB perform complete nitrification (ammonia oxidation to nitrate) and this finding will have far-reaching implications for nitrification research. We review recent work that has changed our perspective on NOB and provides a new basis for future studies on these enigmatic organisms.

Daims H, Lücker S, Wagner M
2016 - Trends Microbiol., in press

Soil microbial carbon use efficiency and biomass turnover in a long-term fertilization experiment in a temperate grassland

Soil microbial carbon use efficiency (CUE), defined as the ratio of organic C allocated to growth over organic C taken up, strongly affects soil carbon (C) cycling. Despite the importance of the microbial CUE for the terrestrial C cycle, very little is known about how it is affected by nutrient availability. Therefore, we studied microbial CUE and microbial biomass turnover time in soils of a long-term fertilization experiment in a temperate grassland comprising five treatments (control, PK, NK, NP, NPK). Microbial CUE and the turnover of microbial biomass were determined using a novel substrate-independent method based on incorporation of 18O from labeled water into microbial DNA. Microbial respiration was 28–37% smaller in all three N treatments (NK, NP, and NPK) compared to the control, whereas the PK treatment did not affect microbial respiration. N-fertilization decreased microbial C uptake, while the microbial growth rate was not affected. Microbial CUE ranged between 0.31 and 0.45, and was 1.3- to 1.4-fold higher in the N-fertilized soils than in the control. The turnover time ranged between 80 and 113 days and was not significantly affected by fertilization. Net primary production (NPP) and the abundance of legumes differed strongly across the treatments, and the fungal:bacterial ratio was very low in all treatments. Structural equation modeling revealed that microbial CUE was exclusively controlled by N fertilization and that neither the abundance of legumes (as a proxy for the quality of the organic matter inputs) nor NPP (as a proxy for C inputs) had an effect on microbial CUE. Our results show that N fertilization did not only decrease microbial respiration, but also microbial C uptake, indicating that less C was intracellularly processed in the N fertilized soils. The reason for reduced C uptake and increased CUE in the N-fertilization treatments is likely an inhibition of oxidative enzymes involved in the degradation of aromatic compounds by N in combination with a reduced energy requirement for microbial N acquisition in the fertilized soils. In conclusion, the study shows that N availability can control soil C cycling by affecting microbial CUE, while plant community-mediated changes in organic matter inputs and P and K availability played no important role for C partitioning of the microbial community in this temperate grassland.

Spohn M, Pötsch EM, Eichorst SA, Woebken D, Wanek W, Richter A
2016 - Soil Biology and Biochemistry, 97: 168-175

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)