Original Papers

Archives of Microbiology

, Volume 154, Issue 2, pp 120-126

First online:

Flexistipes sinusarabici, a novel genus and species of eubacteria occurring in the Atlantis II Deep brines of the Red Sea

  • Gerhard FialaAffiliated withLehrstuhl für Mikrobiologie, Universität Regensburg
  • , Carl R. WoeseAffiliated withDepartment of Microbiology, University of Illinois at Urbana-Champaign
  • , Thomas A. LangworthyAffiliated withDepartment of Microbiology, School of Medicine, University of South Dakota
  • , Karl O. StetterAffiliated withLehrstuhl für Mikrobiologie, Universität Regensburg

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Four isolates of a gram-negative flexible bacterium have been obtained from brine water samples of the Atlantis II Deep of the Red Sea at a depth of 2000 m. One isolate (MAS 10) was studied in detail. Cells are nonmotile, flexible rods, measuring about 0.3 μm in width and 5 to 50 μm in length. The new organisms are heterotrophs growing anaerobically on yeast extract, meat extract, peptone, tryptone, and, less efficiently, on acetate and casamino acids. Growth occurs between 30% and 53°C at pH 6 to 8 in the presence of at least 3% NaCl. The shortest doubling time is 8.5 h under optimal growth conditions. Cells are sensitive to the antibiotics penicillin, ampicillin, vancomycin, and streptomycin, but resistant to tetracyclin and rifamipicin. The GC-content of the DNA is 39 mol%. Based on their 16S rRNA the new isolates group with the general cluster of eubacterial phyla. Since they show no specific relationship to any of them, a new genus is described, which is named Flexistipes, the flexible stick. Type species is Flexistipes sinusarabici strain MAS 10 (DSM 4947).

Key words

Flexistipes Eubacteria Atlantis II Deep brines Red Sea