, Volume 1, Issue 2, pp 94–99

Silicibacter lacuscaerulensis gen. nov., sp. nov., a mesophilic moderately halophilic bacterium characteristic of the Blue Lagoon geothermal lake in Iceland

  • Solveig K. Petursdottir
  • Jakob K. Kristjansson

DOI: 10.1007/s007920050020

Cite this article as:
Petursdottir, S. & Kristjansson, J. Extremophiles (1997) 1: 94. doi:10.1007/s007920050020


Mesophilic, moderately halophilic bacteria were isolated from a silica-rich geothermal lake, the Blue Lagoon in Iceland. The isolates are strictly aerobic, but reduce nitrate to nitrite, and are oxidase- and catalase-positive. The nonsporeforming and nonmotile Gram negative rods are 0.6–0.8 μm in diameter and variable in length (9–18 μm), and contain gas vacuoles. The GC content in their DNA is 66.15%. The minimum, optimum, and maximum temperatures for growth are 22°C, 45°:C, and 50°C, respectively. The isolates do not grow without added salt in the medium and can grow at up to 7% NaCl (w/v). The optimal salinity for growth is 3.5%–4% NaCl. The pH range for growth is 6.5–8.5, with the optimal pH at 7.0. At optimal conditions the bacterium has a doubling time of 80 min. The main cytochrome is a membrane-bound cytochrome c with an α-peak at 549 nm. Sequencing of 16S rRNA from the type strain ITI-1157 revealed it to be a proteobacterium of the α-subclass with the closest relatives being Roseobacter litoralis and Paracoccus kocurii. The new isolates do not contain bacteriochlorophyll a and are considered to represent a new genus and a new species, Silicibacter lacuscaerulensis.

Key words Silica precipitation Geothermal lagoon Moderate halophile Silicibacter lacuscaerulensis Erythrobacter longus Roseobacter litoralis Paracoccus kocurii 

Copyright information

© Springer-Verlag Tokyo 1997

Authors and Affiliations

  • Solveig K. Petursdottir
    • 1
  • Jakob K. Kristjansson
    • 1
  1. 1.Department of Biotechnology, Technological Institute of Iceland, Reykjavik, Iceland IS

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