Bacterial diversity in five Icelandic geothermal waters: temperature and sinter growth rate effects |
| |
Authors: | Dominique J Tobler Liane G Benning |
| |
Institution: | (1) Earth and Biosphere Institute, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK;(2) Present address: School of Geographical and Earth Sciences, University of Glasgow, Gregory Building, Glasgow, G12 8QQ, UK |
| |
Abstract: | The microbial ecology associated with siliceous sinters was studied in five geochemically diverse Icelandic geothermal systems.
Bacterial 16S rRNA clone libraries were constructed from water-saturated precipitates from each site resulting in a total
of 342 bacterial clone sequences and 43 species level phylotypes. In near-neutral, saline (2.6–4.7% salinity) geothermal waters
where sinter growth varied between 10 and ~300 kg year−1 m−2, 16S rRNA gene analyses revealed very low (no OTUs could be detected) to medium (9 OTUs) microbial activity. The most dominant
phylotypes found in these waters belong to marine genera of the Proteobacteria. In contrast, in alkaline (pH = 9–10), meteoric geothermal waters with temperature = 66–96°C and <1–20 kg year−1m−2 sinter growth, extensive biofilms (a total of 34 OTUs) were observed within the waters and these were dominated by members
of the class Aquificae (mostly related to Thermocrinis), Deinococci (Thermus species) as well as Proteobacteria. The observed phylogenetic diversity (i.e., number and composition of detected OTUs) is argued to be related to the physico-chemical
regime prevalent in the studied geothermal waters; alkaliphilic thermophilic microbial communities with phylotypes related
to heterotrophic and autotrophic microorganisms developed in alkaline high temperature waters, whereas halophilic mesophilic
communities dominated coastal geothermal waters. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|