Discriminating the Role of Photosynthetic and Heterotrophic Microbes Triggering Low-Mg Calcite Precipitation in Freshwater Biofilms (Lake Geneva, Switzerland)

Autor: Muriel Pacton, Karine Plée, Daniel Ariztegui
Rok vydání: 2010
Předmět:
Zdroj: Geomicrobiology Journal. 27:391-399
ISSN: 1521-0529
0149-0451
Popis: Field and laboratory experiments in freshwater Lake Geneva (Switzerland) have recently demonstrated a substantial role of biofilms triggering the formation of ooids. However, the precise function and specificity of the microbes involved in this process remained elusive. In this study we compared biofilms lining ooid depressions in the natural environment with those grown under laboratory conditions in a BG11 media. Confocal microscopy, SEM and TEM as well as PCR-DGGE results have been used to accomplish this comparison at both microscopical and geochemical levels, respectively. Carbonate precipitates in the natural environment show that cyanobacteria dominate the microbial community in association with green algae and diatoms all embedded within the EPS. Analogously, low-Mg calcite crystals were formed in the laboratory experiments under light conditions. These crystals are found within the EPS and always associated with photosynthetic microorganisms. The latter in concert with the lack of evidence for th...
Databáze: OpenAIRE
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