• 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

Sulfur in lucinid bivalves inhibits intake rates of a molluscivore shorebird

A forager’s energy intake rate is usually constrained by a combination of handling time, encounter rate and digestion rate. On top of that, food intake may be constrained when a forager can only process a maximum amount of certain toxic compounds. The latter constraint is well described for herbivores with a limited tolerance to plant secondary metabolites. In sulfidic marine ecosystems, many animals host chemoautotrophic endosymbionts, which store sulfur compounds as an energy resource, potentially making their hosts toxic to predators. The red knot Calidris canutus canutus is a molluscivore shorebird that winters on the mudflats of Banc d’Arguin, where the most abundant bivalve prey Loripes orbiculatus hosts sulfide-oxidizing bacteria. In this system, we studied the potential effect of sulfur on the red knots’ intake rates, by offering Loripes with various sulfur content to captive birds. To manipulate toxicity, we starved Loripes for 10 days by removing them from their symbiont’s energy source sulfide. As predicted, we found lower sulfur concentrations in starved Loripes. We also included natural variation in sulfur concentrations by offering Loripes collected at two different locations. In both cases lower sulfur levels in Loripes resulted in higher consumption rates in red knots. Over time the red knots increased their intake rates on Loripes, showing their ability to adjust to a higher intake of sulfur.

Tim Oortwijn, Jimmy de Fouw, Jillian Petersen, Jan A. van Gils
2022 - Oecologia, in press

Individual sweet taste perception influences salivary characteristics after orosensory stimulation with sucrose and non-caloric sweeteners

Emerging evidence suggests a major role for salivary flow and the viscoelastic properties for taste perception and mouthfeel. Sweet-tasting compounds have also been proposed to have an effect on salivary characteristic. However, it is yet not clarified if perceived differences in the sensorial properties of structural diverse sweet tasting compounds contribute to salivary flow and viscoelasticity of saliva as part of mouthfeel and overall taste perception. Here we hypothesized that sensorially diverse sweeteners would affect salivary characteristics differently. Thus, we investigated the salivary flow, viscoelasticity of saliva, and selected influencing factors including the basal oral microbiome from 21 healthy test subjects after orosensory stimulation with sucrose, rebaudioside M (RebM), sucralose, and neohesperidin dihydrochalcone (NHDC) in a cross-over design. All test compounds enhanced the salivary flow by up to 1.51 ± 0.12 g/min for RebM, compared to 1.10 ± 0.09 g/min for water in the first minute after stimulation. The increase in the flow rate was correlated moderately to the individual perceived sweetness (r= 0.3, p< 0.01), but did not differ between the test compounds. The complex viscosity of the saliva was not affected by the test compounds, but analysis of covariance showed that the complex viscosity was associated (p< 0.05) with the concentration of mucin 5B (Muc5B). The oral microbiome showed a typical composition and diversity but was strongly individual-dependent (PERMANOVA: R²=0.76, p< 0.001), and was not associated with the changes in salivary characteristics. In conclusion, the present study indicates an impact of the individual sweetness impression on the flow rate without measurable changes in the complex viscosity of saliva, which may contribute to overall taste perception and mouthfeel of sweet tasting compounds.

Karl CM, Vidakovic A, Pjevac P, Hausmann B, Schleining G, Ley JP, Berry D, Hans J, WEndlin M, Koenig J, Somoza V, Lieder B
2022 - frontiers in Nutrition, in press

Interleukin-11 drives human and mouse alcohol-related liver disease

Objective Alcoholic hepatitis (AH) reflects acute exacerbation of alcoholic liver disease (ALD) and is a growing healthcare burden worldwide. Interleukin-11 (IL-11) is a profibrotic, proinflammatory cytokine with increasingly recognised toxicities in parenchymal and epithelial cells. We explored IL-11 serum levels and their prognostic value in patients suffering from AH and cirrhosis of various aetiology and experimental ALD.
Design IL-11 serum concentration and tissue expression was determined in a cohort comprising 50 patients with AH, 110 patients with cirrhosis and 19 healthy volunteers. Findings were replicated in an independent patient cohort (n=186). Primary human hepatocytes exposed to ethanol were studied in vitro. Ethanol-fed wildtype mice were treated with a neutralising murine IL-11 receptor-antibody (anti-IL11RA) and examined for severity signs and markers of ALD.
Results IL-11 serum concentration and hepatic expression increased with severity of liver disease, mostly pronounced in AH. In a multivariate Cox-regression, a serum level above 6.4 pg/mL was a model of end-stage liver disease independent risk factor for transplant-free survival in patients with compensated and decompensated cirrhosis. In mice, severity of alcohol-induced liver inflammation correlated with enhanced hepatic IL-11 and IL11RA expression. In vitro and in vivo, anti-IL11RA reduced pathogenic signalling pathways (extracellular signal-regulated kinases, c-Jun N-terminal kinase, NADPH oxidase 4) and protected hepatocytes and murine livers from ethanol-induced inflammation and injury.
Conclusion Pathogenic IL-11 signalling in hepatocytes plays a crucial role in the pathogenesis of ALD and could serve as an independent prognostic factor for transplant-free survival. Blocking IL-11 signalling might be a therapeutic option in human ALD, particularly AH.
Effenberger M, Widjaja AA, Grabherr F, Schaefer B, Grander C, Mayr L, Schwaerzler J, Enrich B, Moser P, Fink J, Pedrini A, Jaschke N, Kirchmair A, Pfister A, Hausmann B, Bale R, Putzer D, Zoller H, Schafer S, Pjevac P, Trajanoski Z, Oberhuber G, Adolph T Cook S, Tilg H
2022 - BMJ, in press

Lecture series

DOME Lecture: "Energy Bookkeeping in Ocean Ecosystems"

Alberto Robador Ausejo
Department of Biological Sciences, USC Dornsife, California, USA
12:00 h
hybrid, UBB HS 2