The fingerprint of chemosymbiosis: origin and preservation of isotopic biosignatures in the nonseep bivalve Loripes lacteus compared with Venerupis aurea
| Autor: | Marco Taviani, Christoph Wrede, Anne Dreier, Volker Thiel, Lorena Stannek, Martin Blumenberg, Michael Hoppert, Marco Sigovini |
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| Rok vydání: | 2011 |
| Předmět: |
0106 biological sciences
Nitrogen Ribulose-Bisphosphate Carboxylase 01 natural sciences Applied Microbiology and Biotechnology Microbiology Carbon Cycle 03 medical and health sciences δ34S Animal Shells Glutamate-Ammonia Ligase RNA Ribosomal 16S Botany Sulfur Isotopes Animals Oxidoreductases Acting on Sulfur Group Donors 14. Life underwater Symbiosis 0303 health sciences Carbon Isotopes Subfossil Ecology biology Endosymbiosis δ13C Bacteria Nitrogen Isotopes 030306 microbiology Fossils 010604 marine biology & hydrobiology Carbon fixation RuBisCO Venerupis δ15N biology.organism_classification Bivalvia biology.protein Oxidation-Reduction Sulfur |
| Zdroj: | FEMS microbiology ecology. 81(2) |
| ISSN: | 1574-6941 |
| Popis: | Endosymbionts in marine bivalves leave characteristic biosignatures in their host organisms. Two nonseep bivalve species collected in Mediterranean lagoons, thiotrophic symbiotic Loripes lacteus and filter-feeding nonsymbiotic Venerupis aurea, were studied in detail with respect to generation and presence of such signatures in living animals, and the preservation of these signals in subfossil (late Pleistocene) sedimentary shells. Three key enzymes from sulfur oxidation (APS-reductase), CO(2) fixation (RubisCO) and assimilation of nitrogen [glutamine synthetase (GS)] were detected by immunofluorescence in the bacterial symbionts of Loripes. In Loripes, major activity was derived from GS of the symbionts whereas in Venerupis the host GS is active. In search of geologically stable biosignatures for thiotrophic chemosymbiosis that might be suitable to detect such associations in ancient bivalves, we analyzed the isotopic composition of shell lipids (δ(13)C) and the bulk organic matrix of the shell (δ(13)C , δ(15)N , δ(34)S). In the thiotrophic Loripes, δ(13)C values were depleted compared with the filter-feeding Venerupis by as much as 8.5‰ for individual fatty acids, and 4.4‰ for bulk organic carbon. Likewise, bulk δ(15)N and δ(34)S values were more depleted in recent thiotrophic Loripes. Whereas δ (34)S values were found to be unstable over time, the combined δ(15)N and δ(13)C values in organic shell extracts revealed a specific signature for chemosymbiosis in recent and subfossil specimens. |
| Databáze: | OpenAIRE |
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