Culture growth of testate amoebae under different silicon concentrations.
Testate amoebae with self-secreted siliceous shell platelets ("idiosomes") play an important role in terrestrial silicon (Si) cycles. In this context, Si-dependent culture growth dynamics of idiosomic testate amoebae are of interest. Clonal cultures of idiosomic testate amoebae were analyzed under three different Si concentrations: low (50μmolL-1), moderate/site-specific (150μmolL-1) and high Si supply (500μmolL-1). Food (Saccharomyces cerevisiae) was provided in surplus. (i) Shell size of four different clones of idiosomic testate amoebae either decreased (Trinema galeata, Euglypha filifera cf.), increased (E. rotunda cf.), or did not change (E. rotunda) under the lowest Si concentration (50μmolSiL-1). (ii) Culture growth of idiosomic Euglypha rotunda was dependent on Si concentration. The more Si available in the culture medium, the earlier the entry into exponential growth phase. (iii) Culture growth of idiosomic Euglypha rotunda was dependent on origin of inoculum. Amoebae previously cultured under a moderate Si concentration revealed highest sustainability in consecutive cultures. Amoebae derived from cultures with high Si concentrations showed rapid culture growth which finished early in consecutive cultures. (iv) Si (diluted in the culture medium) was absorbed by amoebae and fixed in the amoeba shells resulting in decreased Si concentrations.
Brandenburg University of Technology Cottbus-Senftenberg, Department Ecology, 03013 Cottbus, Germany. Electronic address: wanner@b-tu.de.
Manfred
M
Wanner
Brandenburg University of Technology Cottbus-Senftenberg, Department Ecology, 03013 Cottbus, Germany.
Barbara
B
Seidl-Lampa
Leibniz-Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Soil Landscape Research, 15374 Müncheberg, Germany.
Axel
A
Höhn
Brandenburg University of Technology Cottbus-Senftenberg, Department Ecology, 03013 Cottbus, Germany; Leibniz-Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Soil Landscape Research, 15374 Müncheberg, Germany.
Daniel
D
Puppe
RWTH Aachen University, Institute of Biology II (Zoology), Worringerweg 3, 52056 Aachen, Germany.
Ralf
R
Meisterfeld
Leibniz-Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Soil Landscape Research, 15374 Müncheberg, Germany; University of Potsdam, Institute of Earth and Environmental Sciences, 14476 Potsdam, Germany.
Michael
M
Sommer
D000656:Amoeba / Q000187:drug effects* / Q000254:growth & development*; D003470:Culture Media / Q000494:pharmacology; D012825:Silicon / Q000494:pharmacology*
D003470:Culture Media; D012825:Silicon
Amoebal silicon; Biosilicification; Consumption; Culture growth dynamics; Euglyphida; Sommer et al. 2006; Terrestrial Si cycle