MEPS 219:1-10 (2001)  -  doi:10.3354/meps219001

Carbon and nitrogen content of transparent exopolymer particles (TEP) in relation to their Alcian Blue adsorption

Anja Engel1,*,**, Uta Passow2,*

1Institut für Meereskunde, 24109 Kiel, Germany
2Marine Science Institute, University of California Santa Barbara, California 93106-6150, USA
*Present address: Alfred-Wegener-Institut für Polar- und Meeresforschung, PF 120161, 27515 Bremerhaven, Germany **E-mail:

ABSTRACT: The carbon and nitrogen content of transparent exopolymer particles (TEP) was determined and related to the concentration of TEP as quantified by a colorimetrical method. TEP were produced in the laboratory from dissolved precursors by laminar or turbulent shear. Dissolved precursors were obtained by 0.2 µm filtration from diatom cultures, with or without nutrient reduction, and from natural diatom populations. The relationship between carbon and TEP was significant, linear and species-specific. Carbon concentration of TEP derived from this relationship concurred with previous findings. Shortage of silicic acid or nitrate in the culture media had no effect on the carbon content of TEP. Molar C:N ratios of TEP were above the Redfield ratio, with a mean value of 26. It is suggested that the nitrogen fraction of TEP can be explained by adsorption of dissolved organic nitrogen (DON) onto TEP. Based on the newly established relationship, concentrations of TEP-derived carbon (TEP-C) were calculated for the Baltic Sea, the coastal Pacific, the North East Atlantic and the Northern Adriatic Sea.

KEY WORDS: Transparent exopolymer particles · TEP · POC · PON · Phytoplankton exudation · Coagulation · Carbon cycling

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