Postdoctoral Positions in Marine Microbiology, Roscoff [France]

Postdoctoral applicant Station Biologique, Roscoff, France
Ecological significance of photoheterotrophic bacteria in the Western Arctic Ocean
We are looking for a foreign applicant for a postdoctoral fellowship at the Station Biologique (Roscoff, France).

We currently witness in the Arctic:
1) a decrease in summer ice cover that exposes sea surface to solar radiation and physical forcings,

2) permafrost thawing and increased river runoff, both leading to an increase in the export to the ocean of organic carbon previously sequestered in the Tundra, and

3) an increase in ultraviolet radiation. These three phenomena favour a growing mineralization of organic carbon through photo-oxidation and bacterial activity, amplifying the increase in atmospheric CO2. At the same time, the exposure of a larger fraction of ocean surface to sun light and the increase in nutrients brought by rivers lead to larger autotrophic production and sequestration of organic carbon. To predict the balance of these processes, we will conduct an extensive study in the Mackenzie River/Beaufort Sea system in August 2009 onboard the Canadian research icebreaker Amundsen.

Photoheterotrophic bacteria, including proteorhodopsin-containing microorganisms are major components in the Arctic Ocean. Their abundance and hybrid metabolism (respiration and phototrophy) will probably make them key players of the actual changes (increased solar radiation and carbon availability).

The global objective of this project is to determine their ecological significance of photoheterotrophic bacteria in the Western Arctic Ocean and understand how natural assemblages will respond to the global change.

Specific aims aim will be:
(1) to quantify and link the abundance and activity of photoheterotrophic bacteria with the
physicochemical and biological parameters of their original environment. Abundance will be assessed by using independent and complementary approaches (infrared fluorometry, pigment analysis, infrared epifluorescence microscopy and Q-PCR). Expression of phototrophic activity will be determined by using real time RT-PCR.

(2) to determine the spatial (longitudinal and vertical) variations of the composition of natural populations. Molecular approaches based on the analysis of specific genes (TTGE, cloning and sequencing of environmental clones) will be used to assess the real extent of the diversity.

Experience and publications in the area of molecular methods used in microbial ecology (environmental clone libraries, quantitative PCR). Although working knowledge of French is not mandatory, it will help integration in the Roscoff laboratory.

French applicants and applicants who have held a pHD/postdoctoral fellowship in France are not eligible.

Applicants have until April 10, 2009 to send a motivation letter, a complete CV, and up to 5 references and their contact information to Christian Jeanthon (jeanthon[ at ], Station Biologique, Adaptation et Diversité en Milieu Marin, 29280 Roscoff, France. Tél : +33 298 292 379. Internet: http://