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International lecture series on N-cycling

 

10.04.2019 - Prof. James Hollibaugh (Department of Marine Sciences University of Georgia, USA)

13:30, Hörsaal II, UZAI, Althanstr. 14

"“Distribution and seasonality of Thaumarchaeota populations in the South Atlantic Bight”

 

Abstract:

Thaumarchaeota closely related to Nitrosopumilus maritimus accounted for a
significant fraction of the transcripts in metatranscriptomes from Georgia, USA, coastal
waters collected in August 2008. Subsequent observations indicated that a midsummer
peak was a regular feature of Thaumarchaeota abundance at this site. Net
growth rates of the Thaumarchaeota population immediately preceding this peak
approach 0.4 d-1. A survey of the South Atlantic Bight (SAB) revealed that the
population was restricted to turbid, nearshore and inshore waters, although a distinct
population of Water Column Group B Thaumarchaeota was identified at depth off the
shelf break. We considered that the inshore peak might be a manifestation of
increased bioturbation and sediment resuspension accompanying summer increases in
fiddler crab populations; however, sediment and water column Thaumarchaeota
populations were phylogenetically distinct. The mid-summer peak occurred during a
period of extremely low concentrations (sub-fM) of free Cu(II), suggesting that this
population has an efficient mechanism for accessing ligand-bound Cu(II) from the
environment. Analysis of several years of data lead us to conclude that spatial
distribution of Thaumarchaeota populations in the SAB are controlled by water column
turbidity, while seasonality of the inshore population is controlled by water
temperature. The peak in Thaumarchaeota abundance coincided with elevated nitrite
concentrations (to 14 μM) in the same samples. Similar mid-summer nitrite peaks
observed in other systems suggest that the two steps of nitrification are decoupled at
water temperatures >20 oC, with implications for nitrogen processing in estuaries
under altered thermal regimes. Current studies seek to identify the mechanism for the
apparent oxidation of covalently-bonded organic N by Thaumarchaeota populations.

 

11.04.2019 - Prof. Dr. Marcel Kuypers (Department of Biogeochemistry, Max Planck Institute for Marine Microbiology
Bremen, Germany)

14:00, Hörsaal 7, UZAII, Althanstr. 14

"Imaging of microbial activity in the sea"

 

 

 

Past lectures

 
18.05.2018 - Linda Hink (Laboratoire Ampère, École Centrale de Lyon,
Université de Lyon, France)

"Why favouring ammonia oxidising archaea could mitigate soil nitrous oxide emissions”

 

04.05.2018 - Michael Schloter (Director of Research Unit for Comparative
Microbiome Analysis, Helmholtz Zentrum Munchen, German Research Center for Environmental Health & Technical University of Munich)

"Global change as a driver for plant-associated microbiomes"

 

9.01.2018 - Christina Biasi (University of Eastern Finland, Finland)

"Climate feedbacks from the Arctic under global change: current knowledge and challenges"

 

05.10.2017 - Pertti Martikainen (University of Eastern Finland, Finland)

"Nitrous oxide emissions from natural northern terrestrial ecosystems"

 

2.06.2017 - Angela Sessitsch (Austrian Institute of Technology)

"The Hidden World within Plants: Ecological Considerations and Functioning of Bacterial Endophytes"

 

19.05.2017 - Manuel Becana (Department of Plant Nutrition, Experimental Station of Aula Dei, Spanish National Research Council, Zaragoza, Spain)

"Nonsymbiotic and Symbiotic Hemoglobins in Plants"

 

 24.01.2017 - Sophie Zechmeister-Boltenstern (Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna)

 

"What we know and don't know about N-gas fluxes"

 

Although it is well established that soils are the dominating source for atmospheric nitrous oxide (N2O), we are still struggling to fully understand the complexity of the underlying microbial production and consumption processes and the links to biotic (e.g. inter- and intraspecies competition, food webs, plant–microbe interaction) and abiotic (e.g. soil climate, physics and chemistry) factors. Recent work shows that a better understanding of the composition and diversity of the microbial community across a variety of soils in different climates and under different land use, as well as plant–microbe interactions in the rhizosphere, may provide a key to better understand the variability of N2O, NO, NHand Nfluxes at the soil–atmosphere interface. Moreover, recent insights into the regulation of the reduction of N2O to dinitrogen (N2) have increased our understanding of N2O exchange. This improved process understanding, building on the increased use of isotope tracing techniques and metagenomics, needs to go along with improvements in measurement techniques for N-gas emission in order to obtain robust field and laboratory datasets for different ecosystem types. Advances in both fields are currently used to improve process descriptions in biogeochemical models, which may eventually be used not only to test our current process understanding from the microsite to the field level, but also used as tools for up-scaling emissions to landscapes and regions and to explore feedbacks of soil N-gas emissions to changes in environmental conditions, land management and land use.

 

 

17.01.2017 - Ulrike Felt (Faculty of Social Sciences, University of Vienna)

"Squeezing Responsibility into Rhythms of Academic Life"

Prof. Felt is the head of the research platform "Responsible Research and Innovation in Academic Practice" (RRI) as well as the Dean of the Faculty of Social Sciences of the University of Vienna. 

Her talk will explore how we can best establish RRI as a core value in academic research and education. This calls for a better understanding of the spectrum of different meanings of responsibility in research practice (ranging from research integrity, over public engagement, open access to anticipation) as well as of the working conditions, which provide time and space for acting in responsible manners, and alignment with ideals of societal relevance.

 

 

 

 

 

 

 

 

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