ID 55 : Microbiological and Ecological Responses to Global Environmental Changes in Polar Regions (MERGE)

Short description of the core IPY project:
MERGE is an umbrella program that aims to understand the responses of terrestrial, limnetic and supraglacial polar ecosystems to climate change. Three key questions have been selected:
Theme 1 “Diversity and biogeography” answers “What taxa are present, how are the communities organized and how are they distributed, and where are they?”
Theme 2 “Food webs and ecosystem evolution” will answer the question “How do high-latitude biota interact and function?”
Theme 3 “Linkages between biological, chemical and physical processes in the supraglacial biome” elucidates “How do physical, chemical and biological processes interact in icy ecosystems?”
See: classic.ipy.org/development/eoi/proposal-details.php?id=55

Period and timing of the project:
Bipolar program with various Arctic and Antarctic fieldwork activities expected between 11/2006 and 09/2009 and laboratory research during IPY

Belgian partners:
- Annick Wilmotte - Centre for Protein Engineering, University of Liège Belgium
- Georges Feller - Biochemistry, University of Liège Belgium
- Alain Hubert - International Polar Foundation Belgium
- Koen Sabbe, Belgium
- Paul De Vos - Ghent University Belgium
- Wim Vyverman - Ghent University Belgium

Belgian contribution:
Proteomic and structure-function studies of cold adaptations. The whole genome sequence of the Antarctic bacterium Pseudoalteromonas haloplanktis, isolated by the Laboratory, has been recently elucidated. Hence, the first objective is to identify the molecular adaptations imposed by life in the cold on the basis of these sequence data. The research will be devoted to the identification, isolation and functional characterization of the structural and regulatory factors permanently synthesized by the cold-adapted bacterium that allow the maintenance of life at low temperatures. Practically, the bacterium will be cultured at decreasing temperatures between 18°C and 0°C. The cellular proteins at each temperature will be compared by 2D electrophoresis (2D-DIGE) and by 2D-Liquid Chromatography in order to identify proteins that are over-expressed at low culture temperatures. These proteins will be identified by mass spectrometry of their tryptic peptides. The effects of the deletion or the overexpression of the main cold-adaptation proteins on the bacterial proteome will be studied. Using these data, a metabolic pattern of cold adaptation will be drawn. Similar experiments will be performed on Antarctic bacteria belonging to different taxonomic groups to refine this pattern. The main cold-induced proteins will be characterized with respect to their specific functions and three-dimensional structure.

Beside the fundamental aspects of cold-adaptation, the proposed proteomic studies will simulate, for the first time, the effects of temperature increases on microbial life at both the cellular and molecular levels. This fundamental knowledge appears to be a prerequisite to evaluate the impacts of a possible climate change in polar environments.

Related campaigns with Belgian contribution:
Summer campaign of the Institut polaire français Paul Emile Victor (IPEV) in Terre Adélie, station Dumont d’Urville (Dr Jean Claude Marx, January-February 2007).

Other resources:
- www.ulg.ac.be/biochlab/