Researchers at the University of Southern Denmark are engaged in the following astrobiolgy-related research areas:
The microbial sulfur cycle and stable sulfur isotopes
The group conducts various different experiments to understand the regulation of the sulfur isotope fractionation during sulfate reduction. The results are used to understand the stable sulfur isotope record from sediments deposit today and through Earth history.
The microbial sulfur and methane cycle of brine seeps in the Gulf of Mexico
At the seafloor of the Gulf of Mexico there are brines seeps where hot high-saline water is flowing from the deep subsurface to the seafloor creating lake-like features. The heavy saltwater is lying as oxygen-free brine pools at the bottom of the ocean having particular no exchange with the overlying seawater. The brines are laden with energy-rich compounds, which is the reason that the brine pools are not dead but contain high concentrations of micro-organisms and their productivity supports a rich animal life. The group wishes to study the microbial and chemical processes associated the sulfur cycle of these brine seeps and study how these processes affect the surrounding environment, and stable isotope probing of DNA and RNA should identify the most active sulfate reducing bacteria. It is also desired to measure the stable sulfur isotope compositions of the most important sulfur compounds and understand how these signals are produced. These data will be used to understand the sulfur isotope record from sulfur deposits through Earth history. The project will be connected the American Seafloor Brine Seep Microbial Observatory lead by Samantha Joye, Georgia University Athens, USA.
Biogeochemical measurements of marine and freshwater sediments
Various techniques to measure the microbial processes in marine and freshwater systems are used:
Cell specific activity of micro-organisms in natural environments
Various methods to identify the cell specific activity of micro-organisms are used: Microautoradiography in combination with in-situ fluorescence hybridisation (MAR-FISH), stable isotope probing of DNA and RNA (SIP) and proteomics.
Kirsten Habicht has lead several international expeditions to sulfide and iron rich lakes in Switzerland and Spain. She has also participated in fieldwork going to Solar Lake; Egypt; Eilat, Israel; Yellowstone National Park, USA; Black Sea and the Galathea 3 Expedition to the oxygen minimum zone out of Chile and Peru. Right now she is planning a field course in Geobiology for master students on Iceland. This course will take place in August 2011.
The group alsop takes part in the The Nordic centre of Earth Evolution (NordCEE) and the CAREX platform on research on life in extreme environments.
The Nordic centre of Earth Evolution (NordCEE) was founded in 2005 as a centre of excellence under the Danish National Research Foundation. The centre is led by Professor Don Canfield and is a collaboration between research groups at the Institute of Biology, University of Southern Denmark, Odense; the Geological Museum, and the Department of Geography and Geology at the University of Copenhagen and the Swedish Museum of Natural History, Stockholm, and it includes about 35 people. The goal of the centre is to untangle the dynamics between biological evolution, element cycling, and Earth-surface change. The centre combines research areas within microbiology, molecular ecology, biogeochemistry, geology, and modelling to reconstructing the history of biological and environmental changes with the special interest to understand Earth oxygenation during Precambrian. The research areas includes modern extreme environments that could resemble Early Earth oceans like anoxic water columns of marine and freshwater systems, microbial mats, hydrothermal vents, and high saline areas. In these systems, we combine biological and chemical measurements with geological stable biomarkers (e.g. stable carbon and sulfur isotopes) with the aim to compare the data with studies of Precambrian sediments.