Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | Bacterial epibionts of Daphnia: a potential route for the transfer of dissolved organic carbon in freshwater food webs |
| Abstract | The identification of interacting species and elucidation of their mode of interaction may be crucial to understand ecosystem-level processes. We analysed the activity and identity of bacterial epibionts in cultures of Daphnia galeata and of natural daphnid populations. Epibiotic bacteria incorporated considerable amounts of dissolved organic carbon (DOC), as estimated via uptake of tritiated leucine: three times more tracer was consumed by microbes on a single Daphnia than in 1 ml of lake water. However, there was virtually no incorporation if daphnids were anaesthetised, suggesting that their filtration activity was essential for this process. Microbial DOC uptake could predominantly be assigned to microbes that were located on the filter combs of daphnids, where the passage of water would ensure a continuously high DOC supply. Most of these bacteria were Betaproteobacteria from the genus Limnohabitans. Specifically, we identified a monophyletic cluster harbouring Limnohabitans planktonicus that encompassed sequence types from D. galeata cultures, from the gut of Daphnia magna and from daphnids of Lake Zurich. Our results suggest that the epibiotic growth of bacteria related to Limnohabitans on Daphnia spp. may be a widespread and rather common phenomenon. Moreover, most of the observed DOC flux to Daphnia in fact does not seem to be associated with the crustacean biomass itself but with its epibiotic microflora. The unexplored physical association of daphnids with heterotrophic bacteria may have considerable implications for our understanding of carbon transfer in freshwater food webs, that is, a trophic 'shortcut' between microbial DOC uptake and predation by fish. © 2014 International Society for Microbial Ecology. |
| Source | The ISME journal (Online) 8 (9), pp. 1808–1819 |
| Keywords | Daphniadissolved organic carbonepibiontsfood websfresh watersymbiosis |
| Journal | The ISME journal (Online) |
| Editor | Nature Publishing Group, London, Regno Unito |
| Year | 2014 |
| Type | Articolo in rivista |
| DOI | 10.1038/ismej.2014.39 |
| Authors | Ester Maria Eckert; Jakob Pernthaler |
| Text | 355760 2014 10.1038/ismej.2014.39 Scopus 2 s2.0 84906943194 Daphnia dissolved organic carbon epibionts food webs fresh water symbiosis Bacterial epibionts of Daphnia a potential route for the transfer of dissolved organic carbon in freshwater food webs Ester Maria Eckert; Jakob Pernthaler Ester Maria Eckert CNR ISE; Jakob Pernthaler Limnological Station, Institute of Plant Biology, University of Zurich, Seestrasse 187, 8802 Kilchberg, Switzerland The identification of interacting species and elucidation of their mode of interaction may be crucial to understand ecosystem level processes. We analysed the activity and identity of bacterial epibionts in cultures of Daphnia galeata and of natural daphnid populations. Epibiotic bacteria incorporated considerable amounts of dissolved organic carbon DOC , as estimated via uptake of tritiated leucine three times more tracer was consumed by microbes on a single Daphnia than in 1 ml of lake water. However, there was virtually no incorporation if daphnids were anaesthetised, suggesting that their filtration activity was essential for this process. Microbial DOC uptake could predominantly be assigned to microbes that were located on the filter combs of daphnids, where the passage of water would ensure a continuously high DOC supply. Most of these bacteria were Betaproteobacteria from the genus Limnohabitans. Specifically, we identified a monophyletic cluster harbouring Limnohabitans planktonicus that encompassed sequence types from D. galeata cultures, from the gut of Daphnia magna and from daphnids of Lake Zurich. Our results suggest that the epibiotic growth of bacteria related to Limnohabitans on Daphnia spp. may be a widespread and rather common phenomenon. Moreover, most of the observed DOC flux to Daphnia in fact does not seem to be associated with the crustacean biomass itself but with its epibiotic microflora. The unexplored physical association of daphnids with heterotrophic bacteria may have considerable implications for our understanding of carbon transfer in freshwater food webs, that is, a trophic shortcut between microbial DOC uptake and predation by fish. © 2014 International Society for Microbial Ecology. 8 Published version http //www.scopus.com/inward/record.url eid=2 s2.0 84906943194 partnerID=q2rCbXpz Articolo 2014_ISME_Journal_8_1808_1819.pdf Articolo in rivista Nature Publishing Group 1751 7370 The ISME journal Online The ISME journal Online ISME j. Online The ISME journal Online International Society for Microbial Ecology journal Online estermaria.eckert ECKERT ESTER MARIA TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |