Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.limno.2008.05.002
Titel (primär) Utilisation of leucine by several phytoplankton species
Autor Kamjunke, N.; Tittel, J.
Quelle Limnologica
Erscheinungsjahr 2008
Department SEEFO
Band/Volume 38
Heft 3-4
Seite von 360
Seite bis 366
Sprache englisch
Keywords Algae; Amino acids; Bacteria; Competition; Cyanobacteria; DOC; Leucine; Mixotrophy
Abstract Since amino acids represent an important component of dissolved organic carbon in lakes, we investigated the uptake and consumption of leucine by several phytoplankton species. Firstly, we measured the leucine uptake of 28 phytoplankton species (several cyanobacteria and chlorophytes, one diatom, and one euglenophyte) and the uptake kinetics by a chlorophyte (Ankistrodesmus gracilis) compared to that of heterotrophic bacteria. Furthermore, we tested whether the algae can decrease the concentration of leucine in the light to lower levels than in darkness (hypothesis 1), and whether algae with high minimum substrate requirements exhibit higher consumption rates at plentiful concentrations compared to algae with high substrate reduction capability but low maximum consumption rate (hypothesis 2). Thirteen species of cyanobacteria and chlorophytes showed leucine uptake. Specific uptake rates by A. gracilis were lower in the light than in the dark and much lower than that of heterotrophic bacteria. In the consumption experiments, several algae consumed leucine with higher rates and to lower residual concentrations in the dark than in the light, but with lower rates and not to lower concentrations than heterotrophic bacteria. Residual concentrations and consumption rates were not related to algal cell volume and chlorophyll content. Consumption rates were negatively related to residual concentrations, i.e. algae with higher consumption rates also depleted leucine to lower concentrations. Although the hypotheses were not supported, several algae were capable of removing leucine to equally low concentrations as bacteria so that algal uptake of amino acids is potentially important in natural waters.
dauerhafte UFZ-Verlinkung
Kamjunke, N., Tittel, J. (2008):
Utilisation of leucine by several phytoplankton species
Limnologica 38 (3-4), 360 - 366 10.1016/j.limno.2008.05.002