• CUBE - Computational Systems Biology

  • DOME - Microbial Ecology

  • TER - Terrestrial Ecosystem Research

DMES News

  • DoME hosted "Let's talk about symbiosis" workshop

    16.11.18
    Event

    This week, DoME hosted the 11th „Let’s talk about symbiosis“ workshop. For one day, students, PhD students, postdocs and PIs interested in microbial symbiosis got together to discuss their current and future research. The workshop is one of the activities ...

  • Habilitation of Marc Mussmann

    19.10.18
    News

    Marc Mussmann received his Venia Legendi from the University of Bremen after his habilitation lecture "Microbial sulfur oxidation in coastal marine sediments" at the Max-Planck-Institute for Marine Microbiology. Congratulations Privatdozent Dr. Marc!

  • Hochschuljubiläumsstiftung funding for Petra Pjevac and Andrew Giguere

    12.10.18
    News

    The Hochschuljubiläumsstiftung of the City of Vienna awarded funding to Petra and Andrew for their project "Can soil help the city breathe?". Petra and Andrew will investigate the capacity of different types of urban green spaces to serve as ...

  • ORF3 TV documentary on the human microbiome

    04.10.18
    Outreach

    Arno Schintlmeister, Buck Hanson, David Berry, and Alexander Loy are featured on Austrian TV (ORF3) in the documentary 'Treffpunkt Medizin: Superorgan Mikrobiom' about the human microbiome. They talk about the importance of the gut microbiota for human health, such as for the ...

Latest publications

Growth explains microbial carbon use efficiency across soils differing in land use and geology

The ratio of carbon (C) that is invested into microbial growth to organic C taken up is known as microbial carbon use efficiency (CUE), which is influenced by environmental factors such as soil temperature and soil moisture. How microbes will physiologically react to short-term environmental changes is not well understood, primarily due to methodological restrictions. Here we report on two independent laboratory experiments to explore short-term temperature and soil moisture effects on soil microbial physiology(i.e. respiration, growth, CUE, and microbial biomass turnover): (i) a temperature experiment with 1-day pre-incubation at 5, 15 and 25 °C at 60% water holding capacity (WHC), and (ii) a soil moisture/oxygen (O2) experiment with 7-day pre-incubation at 20 °C at 30%, 60% WHC (both at 21% O2) and 90% WHC at 1% O2. Experiments were conducted with soils from arable, pasture and forest sites derived from both silicate and limestone bedrocks. We found that microbial CUE responded heterogeneously though overall positively to short-term temperature changes, and decreased significantly under high moisture level (90% WHC)/suboxic conditions due to strong decreases in microbial growth. Microbial biomass turnover time decreased dramatically with increasing temperature, and increased significantly at high moisture level (90% WHC)/suboxic conditions. Our findings reveal that the responses of microbial CUE and microbial biomass turnover to short-term temperature and moisture/O2 changes depended mainly on microbial growth responses and less on respiration responses to the environmental cues, which were consistent across soils differing in land use and geology.

Zheng Q, Hu Y, zhang S, Noll L, Boeckle T, Richter A, Wanek W
2019 - Soil Biology and Biochemistry, 128: 45-55

Combination of techniques to quantify the distribution of bacteria in their soil microhabitats at different spatial scales

To address a number of issues of great societal concern at the moment, like the sequestration of carbon, information is direly needed about interactions between soil architecture and microbial dynamics. Unfortunately, soils are extremely complex, heterogeneous systems comprising highly variable and dynamic micro-habitats that have significant impacts on the growth and activity of inhabiting microbiota. Data remain scarce on the influence of soil physical parameters characterizing the pore space on the distribution and diversity of bacteria. In this context, the objective of the research described in this article was to develop a method where X-ray microtomography, to characterize the soil architecture, is combined with fluorescence microscopy to visualize and quantify bacterial distributions in resin-impregnated soil sections. The influence of pore geometry (at a resolution of 13.4 μm) on the distribution of Pseudomonas fluorescens was analysed at macro- (5.2 mm × 5.2 mm), meso- (1 mm × 1 mm) and microscales (0.2 mm × 0.2 mm) based on an experimental setup simulating different soil architectures. The cell density of P. fluorescenswas 5.59 x 107(SE 2.6 x 106) cells g−1 soil in 1–2 mm and 5.84 x 107(SE 2.4 x 106) cells g−1 in 2–4 mm size aggregates soil. Solid-pore interfaces influenced bacterial distribution at micro- and macroscale, whereas the effect of soil porosity on bacterial distribution varied according to three observation scales in different soil architectures. The influence of soil porosity on the distribution of bacteria in different soil architectures was observed mainly at the macroscale, relative to micro- and mesoscales. Experimental data suggest that the effect of pore geometry on the distribution of bacteria varied with the spatial scale, thus highlighting the need to consider an “appropriate spatial scale” to understand the factors that regulate the distribution of microbial communities in soils. The results obtained to date also indicate that the proposed method is a significant step towards a full mechanistic understanding of microbial dynamics in structured soils.

Juyal A, Otten W, Falconer R, Hapca S, Schmidt H, Baveye PC, Eickhorst T
2019 - Geoderma, 334: 165-174

Sulfate is transported at significant rates through the symbiosome membrane and is crucial for nitrogenase biosynthesis

Legume-rhizobia symbioses play a major role in food production for an ever growing human population. In this symbiosis, dinitrogen is reduced ('fixed') to ammonia by the rhizobial nitrogenase enzyme complex and is secreted to the plant host cells, while dicarboxylic acids derived from photosynthetically-produced sucrose are transported into the symbiosomes and serve as respiratory substrates for the bacteroids. The symbiosome membrane contains high levels of SST1 protein, a sulfate transporter. Sulfate is an essential nutrient for all living organisms, but its importance for symbiotic nitrogen fixation and nodule metabolism has long been underestimated. Using chemical imaging, we demonstrate that the bacteroids take up 20-fold more sulfate than the nodule host cells. Furthermore, we show that nitrogenase biosynthesis relies on high levels of imported sulfate, making sulfur as essential as carbon for the regulation and functioning of symbiotic nitrogen fixation. Our findings thus establish the importance of sulfate and its active transport for the plant-microbe interaction that is most relevant for agriculture and soil fertility. 

Schneider S, Schintlmeister A, Becana M, Wagner M, Woebken D, Wienkoop S
2018 - Plant Cell Environ, in press

Lecture series

Toward a predictive understanding of microbiome response to environmental change in peatlands

Joel Kostka
Georgia Institute of Technology, Atlanta, USA
03.12.2018
13:30 h
Lecture Hall 5, UZA II