Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's cave
| Autor: | Aldo Lepidi, Paola Cacchio, Claudia Ercole, Giorgio Cappuccio |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
geography
QE1-996.5 geography.geographical_feature_category Bacteria QH301-705.5 Geochemistry Geology karst Karst chemistry.chemical_compound Calcium carbonate Cave chemistry cave calcium carbonate precipitation Biology (General) Geomorphology Deposition (chemistry) Calcium carbonate precipitation Earth-Surface Processes |
| Zdroj: | International Journal of Speleology, Vol 30, Iss 1-4, Pp 69-79 (2001) International Journal of Speleology (Testo stamp.) 30A (2001): 69–79. info:cnr-pdr/source/autori:Ercole C., Cacchio P., Cappuccio G., Lepidi A./titolo:Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's cave/doi:/rivista:International Journal of Speleology (Testo stamp.)/anno:2001/pagina_da:69/pagina_a:79/intervallo_pagine:69–79/volume:30A |
| ISSN: | 0392-6672 |
| Popis: | Bacteria make a significant contribution to the accumulation of carbonate in several natural habitats where large amounts of carbonates are deposited. However, the role played by microbial communities in speleothem formation (stalactites, stalagmites etc.) in caves is still unclear. In bacteria carbonate is formed by autotrophic pathways, which deplete CO2 from the environment, and by heterotrophic pathways, leading to active or passive precipitation. We isolated cultivable heterotrophic microbial strains, able to induce CaCO3 precipitation in vitro, from samples taken from speleothems in the galleries of Stiffe’s cave, L’Aquila, Italy. We found a large number of bacteria in the calcite formations (1 x 104 to 5 x 109 cells g-1). Microscopic examination, in laboratory conditions at different temperatures, showed that most of the isolates were able to form calcium carbonate microcrystals. The most crystalline precipitates were observed at 32°C. No precipitation was detected in un-inoculated controls media or in media that had been inoculated with autoclaved bacterial cells. X-ray diffraction (XRD) analysis showed that most of the carbonate crystals produced were calcite. Bacillus strains were the most common calcifying isolates collected from Stiffe’s Cave. Analysis of carbonate-solubilization capability revealed that the non-calcifying bacteria were carbonate solubilizers. |
| Databáze: | OpenAIRE |
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