Distribution and activity of chemolithoautotrophic microorganisms in Baltic pelagic redoxclines

• Applicant: Professor Dr. Matthias Labrenz
• Subject Area: Microbial Ecology and Applied Microbiology
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29302793

Pelagic redoxclines of the central Baltic Sea are characterized by high carbondioxide (CO2) dark fixation rates. This process is driven by chemolithoautotrophicbacteria and may correspond up to 30 % of the primary production in the euphoticlayer. Despite this significant impact, the knowledge about respective chemolithoautotrophicassemblages is still low. Thus, using 16S rRNA gene probe techniques incombination with the detection of 14CO2 incorporation on single cell level (MICROCARD-FISH), cell counts of chemolithoautotrophic microorganisms will bedetermined throughout the whole redoxcline. In particular, autotrophic nitratereducingas well as potentially autotrophic metal-reducing microorganisms will beexamined more closely. Detailed data about the autotrophic diversity and itsquantitative distribution will be gained by cloning and quantitative PCR of CO2-fixation genes (coding for the Calvin-, reductive TCA- and 3-hydroxypropionatecycle), which will be used as functional markers.

• DFG Programme: Research Grants