Amino sugars

Organic nitrogen compounds in marine and freshwater systems as indicators for production and degradation of organic material

Transformation of organic matter in aquatic systems is governed by bacterial activity. Particulate material produced by organisms present in the water column is partly degraded by bacteria in the water column and/or sinks to the sediment. We investigate processes related to degradation by analyzing mainly amino sugars, organic nitrogen compounds present in algae, animal tissue and bacteria. Some amino sugars are particularly interesting since they are only present in bacterial cell wall. Using high performance anion exchange chromatography (HPAEC) we determine concentrations in the water column and in the underlying sediments. The additional determination of bacterial populations using fluorescence in-situ hybridization (FISH) and the combination of these data with isotopic measurements of amino sugars will contribute to a better understanding of the degradation processes in the water column and in the underlying sediments.
Our research focuses on two basins with a permanent anoxic layer: the Black Sea, as a marine system, and Lake Lugano as a freshwater system.

Funding

• Eawag
• Swiss Federal Institute of Technology Zurich (ETH)

Publications

• Niggemann, J. and Schubert, C.J. (2006) Sources and fate of amino sugars in coastal Peruvian sediments. - Geochimica Cosmochimica Acta, Vol. 70 (9). 2229-2237.
• Klauser, L. (2007) Distribution of amino sugars in a lacustrine and a marine environment. - ETH. Diss. 17202.