|Heterotrophic utilisation of biochemical compounds in antarctic waters|
Bölter, M.; Dawson, R. (1982). Heterotrophic utilisation of biochemical compounds in antarctic waters. Neth. J. Sea Res. 16: 315-332
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
|Authors|| || Top |
The heterotrophic utilisation of amino acids and carbohydrates (mono- and disaccharides) was investigated November-December 1980 on water samples taken from the Falkland Islands to the ice-edge of the Weddell Sea and Bransfield Strait. The uptake of 14C-labelled compounds and their respiration was measured with consideration of the natural concentration of the substrates which were measured directly by high performance liquid chromatography with fluorescent detection. All incubations were carried out at in situ temperatures with trace amounts of labelled compounds without kinetic approach. The results show wide variations in microbial activity and actual substrate concentration which may be related to the physiological state and biomass of phytoplankton standing stock, dominated by Phaeocystis sp. and Thalassiosira sp. Microbial activities and biomass production were found to be comparable with other areas, e.g. the Baltic Sea. The composition of the dissolved and particulate matter in terms of amino acids, proteins, sugars and polysaccharides show many differences to other ecosystems. High levels of bound amino acids (dissolved proteins) often exceeding mg levels were found, Particularly in waters with high chlorophyll contents ( up to 30 µg .l-1 ) where the plankton populations physiological state was poor. Analysis of filtered particulate matter after water extraction and exhaustive hydrolysis showed that healthy plankton cells produced large quantities of high energy nitrogen compounds centred around glutamine and its degradation products. These products could be found in the free-pool of amino acids, only traces following the breakdown of planktonic organisms. A storage of proteinaceous matter seems to be a characteristic feature of the Antarctic ecosystem.