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| Titel |
Calcium Biomineralization in Sediment of Lake Acigol, an Hypersaline Lake in SW Turkey |
| VerfasserIn |
Nurgül Celik Balci, Meryem Menekse, Seref Sonmez, Nevin Gul Karaguler |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034118
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| Zusammenfassung |
| The study of biomineralization in (hyper) saline environments is important for two reasons,
1-it can extend our knowledge about the earliest microbial life on Earth which may have been
halophilic 2-because of the presence of hypersaline conditions on Mars, the analog
environments in Earth may have implications for the possibility of life on Mars. We
examine calcium biomineralization in Lake Acigol, a unique hypersaline lake in
southwest Turkey by integrating geochemical and microbiological approaches.
Lake Acigol is a perennial lake with a maximum salinity of about 200 g/L and
covers an area of 55-60 km2and is one of the main salt reservoirs of Turkey. Water,
sediment and core samples were taken from the lake and salty ponds around the
lake during the field excursion. The water chemistry revealed relatively high Na
and SO4 concentrations both in the lake (30 gr/L, 33.36 gr/L), and the ponds (100
mg/L, 123 mg/L). The mineralogical analyses of sediments showed gypsum, halite,
carbonate (aragonite, huntite) precipitation in the lake and ponds. We employed
culture-dependent (16s rRNA cloning method, enrichment culture), and -independent
techniques to study microbial diversity in Lake Aci gol. Sediment samples were used to
isolate Halophilic sp. (e.g. salinicoccus roseus , Dunella sp.) under salinities that
were similar to those measured in the lake water to further use in the laboratory
Ca-precipitation experiments. For the precipitation experiments, liquid and solid
culture media with various salinities ( 6-25 %) in addition to one similar to the
lake water were prepared. In order to determine effect of Mg2+-Ca2+ molar ratio
on mineralogy and the rate of precipitation, media with different Ca2+and Mg2+
concentrations were also prepared. Our preliminary results indicate that the halophilic
bacteria play active role in the precipitation of Ca-minerals but the geochemical
conditions are clearly influential. The results also point out that in the Lake Aci
gol C, N, P, Ca and Mg cycles may be coupled due to bacterial biomineralization. |
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