Mesozooplankton taurine production and prokaryotic uptake in the northern Adriatic Sea

Elisabeth L. Clifford, Daniele De Corte, Chie Amano, Paolo Paliaga, Ingrid Ivančić, Victor Ortiz, Mirjana Najdek, Gerhard J. Herndl, Eva Sintes

Dissolved free taurine, an important osmolyte in phytoplankton and metazoans, has been shown to be a significant carbon and energy source for prokaryotes in the North Atlantic throughout the water column. However, the extent of the coupling between taurine production and consumption over a seasonal cycle has not been examined yet. We determined taurine production by abundant crustacean zooplankton and its role as a carbon and energy source for several prokaryotic taxa in the northern Adriatic Sea over a seasonal cycle. Taurine concentrations were generally in the low nanomolar range, reaching a maximum of 22 nmol L−1 in fall during a Pseudonitzschia bloom and coinciding with the highest zooplankton taurine release rates. Taurine accounted for up to 5% of the carbon, 11% of the nitrogen, and up to 71% of the sulfur requirements of heterotrophic prokaryotes. Members of the Roseobacter clade, Alteromonas, Thaumarchaeota, and Euryarchaeota exhibited higher cell-specific taurine assimilation rates than SAR11 cells. However, cell-specific taurine and leucine assimilation were highly variable in all taxa, suggesting species and/or ecotype specific utilization patterns of taurine and dissolved free amino acids. Copepods were able to cover the bulk taurine requirements of the prokaryotic communities in fall and winter and partly in the spring–summer period. Overall, our study emphasizes the significance of taurine as a carbon and energy source for the prokaryotic community in the northern Adriatic Sea and the importance of crustacean zooplankton as a significant source of taurine and other organic compounds for the heterotrophic prokaryotic community.

Functional and Evolutionary Ecology
External organisation(s)
Japan Agency for Marine-Earth Science and Technology, Juraj Dobrila University of Pula, Center for Marine Research, Institute Ruder Boskovic (RBI), Royal Netherlands Institute for Sea Research, Utrecht University, Centro Oceanográfico de Murcia, Universität Wien
Limnology and Oceanography
Publication date
Peer reviewed
Austrian Fields of Science 2012
106021 Marine biology
ASJC Scopus subject areas
Oceanography, Aquatic Science
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