• CUBE - Computational Systems Biology

  • DOME - Microbial Ecology

  • TER - Terrestrial Ecosystem Research

News

  • Marie Curie Fellowship for Vincent Delafont

    30.06.16
    People

    Vincent Delafont received a Marie Skłodowska-Curie Research Fellowship to work at DoME with Matthias Horn on his project "Host-microbe interactions involving microbial dark matter: biology and evolution of a ubiquitous group of intracellular bacteria (Hidden Life)". Congratulations!

      ...

  • DoME at Kamptal

    30.06.16
    Event

    The DoME team explored the Kamptal near Zöbing including a visit of a traditional wine tavern (Heuriger) and a bath in river Kamp.

  • Job opening: Group Leader Position

    27.06.16
    Personal

    The Division of Computational Systems Biology at the University of Vienna is offering a

    Group Leader Position in Bioinformatics

    CUBE - the division of Computational Systems Biology - is part of the Department of Microbiology and Ecosystem Science of the ...

  • DMES Seminar

    22.06.16
    News
    Thursday 23rd June:
    Hannes Schmidt (Division of Microbial Ecology)
    ''Rice-associated diazotrophs''
     
    Thursday 30th June:
    Alexander Platzer (Computational Systems Biology)
    ''Combinatorial challenge with consensus''
     
    All seminars take place at 12 midday in Hörsaal II, UZA I

Latest publications

Exploring the metabolic potential of microbial communities in ultra-basic, reducing springs at The Cedars, CA, USA: Experimental evidence of microbial methanogenesis and heterotrophic acetogenesis

Present-day serpentinization generates groundwaters with conditions (pH > 11, Eh < −550 mV) favorable for the microbial and abiotic production of organic compounds from inorganic precursors. Elevated concentrations of methane, C2-C6 alkanes, acetate, and formate have been detected at these sites, but the microbial or abiotic origin of these compounds remains unclear. While geochemical data indicate that methane at most sites of present-day serpentinization is abiogenic, the stable carbon, hydrogen, and clumped isotope data as well as the hydrocarbon gas composition from The Cedars, CA, USA, are consistent with a microbial origin for methane. However, there is no direct evidence of methanogenesis at this site of serpentinization. We report on laboratory experiments in which the microbial communities in fluids and sediments from The Cedars were incubated with 13C labeled substrates. Increasing methane concentrations and the incorporation of 13C into methane in live experiments, but not in killed controls, demonstrated that methanogens converted methanol, formate, acetate (methyl group), and bicarbonate to methane. The apparent fractionation between methane and potential substrates (α13CCH4-CO2(g) = 1.059 to 1.105, α13CCH4-acetate = 1.042 to 1.119) indicated that methanogenesis was dominated by the carbonate reduction pathway. Increasing concentrations of volatile organic acid anions indicated microbial acetogenesis. α13CCO2(g)-acetate values (0.999 to 1.000), however, were inconsistent with autotrophic acetogenesis, thus suggesting that acetate was produced through fermentation. This is the first study to show direct evidence of microbial methanogenesis and acetogenesis by the native microbial community at a site of present-day serpentinization.

Kohl L, Cumming E, Cox A, Rietze A, Morrissey L, Lang SQ, Richter A, Suzuki S, Nealson KH, Morrill PL
2016 - Journal of Geophysical Research Biogeosciences, 4: 1203-1220

Plant-derived compounds stimulate the decomposition of organic matter in arctic permafrost soils

Arctic ecosystems are warming rapidly, which is expected to promote soil organic matter (SOM) decomposition. In addition to the direct warming effect, decomposition can also be indirectly stimulated via increased plant productivity and plant-soil C allocation, and this so called “priming effect” might significantly alter the ecosystem C balance. In this study, we provide first mechanistic insights into the susceptibility of SOM decomposition in arctic permafrost soils to priming. By comparing 119 soils from four locations across the Siberian Arctic that cover all horizons of active layer and upper permafrost, we found that an increased availability of plant-derived organic C particularly stimulated decomposition in subsoil horizons where most of the arctic soil carbon is located. Considering the 1,035 Pg of arctic soil carbon, such an additional stimulation of decomposition beyond the direct temperature effect can accelerate net ecosystem C losses, and amplify the positive feedback to global warming.

Wild B, Gentsch N, Capek P, Diakova K, Alves RJ, Barta J, Gittel A, Hugelius G, Knoltsch A, Kuhry P, Lashchinskiy N, Mikutta R, Palmtag J, Schleper C, Schnecker J, Shibistova O, Takriti M, Torsvik VL, Urich T, Watzka M, Santruckova H, Guggenberger G, Richter A
2016 - Scientific Reports, 6: 11

Deep metagenome and metatranscriptome analyses of microbial communities affiliated with an industrial biogas fermenter, a cow rumen, and elephant feces reveal major differences in carbohydrate hydrolysis strategies.

The diverse microbial communities in agricultural biogas fermenters are assumed to be well adapted for the anaerobic transformation of plant biomass to methane. Compared to natural systems, biogas reactors are limited in their hydrolytic potential. The reasons for this are not understood.
In this paper, we show that a typical industrial biogas reactor fed with maize silage, cow manure, and chicken manure has relatively lower hydrolysis rates compared to feces samples from herbivores. We provide evidence that on average, 2.5 genes encoding cellulolytic GHs/Mbp were identified in the biogas fermenter compared to 3.8 in the elephant feces and 3.2 in the cow rumen data sets. The ratio of genes coding for cellulolytic GH enzymes affiliated with the Firmicutes versus the Bacteroidetes was 2.8:1 in the biogas fermenter compared to 1:1 in the elephant feces and 1.4:1 in the cow rumen sample. Furthermore, RNA-Seq data indicated that highly transcribed cellulases in the biogas fermenter were four times more often affiliated with the Firmicutes compared to the Bacteroidetes, while an equal distribution of these enzymes was observed in the elephant feces sample.
Our data indicate that a relatively lower abundance of bacteria affiliated with the phylum of Bacteroidetes and, to some extent, Fibrobacteres is associated with a decreased richness of predicted lignocellulolytic enzymes in biogas fermenters. This difference can be attributed to a partial lack of genes coding for cellulolytic GH enzymes derived from bacteria which are affiliated with the Fibrobacteres and, especially, the Bacteroidetes. The partial deficiency of these genes implies a potentially important limitation in the biogas fermenter with regard to the initial hydrolysis of biomass. Based on these findings, we speculate that increasing the members of Bacteroidetes and Fibrobacteres in biogas fermenters will most likely result in an increased hydrolytic performance.

Güllert S, Fischer MA, Turaev D, Noebauer B, Ilmberger N, Wemheuer B, Alawi M, Rattei T, Daniel R, Schmitz RA, Grundhoff A, Streit WR
2016 - Biotechnol Biofuels, 121

Lecture series

Searching for Influencers via Optimal Percolation: from Twitter to the Brain

Flaviano Morone
Levich Institute
04.07.2016
13:00 h
City College of New York