Carbon isotope fractionation in developing natural phototrophic biofilms

Autor: Staal, M., Thar, R., Kühl, M., Van Loosdrecht, M. C. M., Wolf, G., De Brouwer, J. F. C., Rijstenbil, J. W.
Přispěvatelé: Department of Marine Microbiology [Yerseke], Netherlands Institute of Ecology (NIOO-KNAW), Marine Biological Laboratory, Institute of Biology, Department of Environmental Biotechnology, Delft University of Technology (TU Delft)
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Biogeosciences Discussions
Biogeosciences Discussions, European Geosciences Union, 2007, 4 (1), pp.69-98
ISSN: 1810-6277
1810-6285
Popis: International audience; Natural phototrophic biofilms are influenced by a broad array of abiotic and biotic factors and vary over temporal and spatial scales. Different developmental stages can be distinguished and growth rates will vary due to the thickening of the biofilm, which are expected to lead to a limitation of light or mass transport. In this study it is shown that a variation of the availability of CO2 leads to a shift in fractionation, thereby affecting ?13C signatures during the successive developmental stages. For phototrophic freshwater biofilms it was found that the ?13C value became less negative with the thickening of the biofilm, while the opposite trend in ?13C values was found in marine biofilms. Modeling and pH profiling indicated that the change in the freshwater system was caused by an increase in CO2 limitation resulting in an increase of HCO3? as C-source. The opposite trend in the marine system could be explained by a higher heterotrophic biomass and activity causing a higher carbon recycling and thereby lower ?13C values. We conclude that ?13C was more related to the net areal photosynthesis rate and carbon recycling, rather than to the growth rate of the biofilms.
Databáze: OpenAIRE
Externí odkaz: