Extremophiles

, Volume 13, Issue 3, pp 541–555

The Exiguobacterium genus: biodiversity and biogeography

  • Tatiana A. Vishnivetskaya
  • Sophia Kathariou
  • James M. Tiedje
Original Paper

DOI: 10.1007/s00792-009-0243-5

Cite this article as:
Vishnivetskaya, T.A., Kathariou, S. & Tiedje, J.M. Extremophiles (2009) 13: 541. doi:10.1007/s00792-009-0243-5

Abstract

Bacteria of the genus Exiguobacterium are low G + C, Gram-positive facultative anaerobes that have been repeatedly isolated from ancient Siberian permafrost. In addition, Exiguobacterium spp. have been isolated from markedly diverse sources, including Greenland glacial ice, hot springs at Yellowstone National Park, the rhizosphere of plants, and the environment of food processing plants. Strains of this hereto little known bacterium that have been retrieved from such different (and often extreme) environments are worthy of attention as they are likely to be specifically adapted to such environments and to carry variations in the genome which may correspond to psychrophilic and thermophilic adaptations. However, comparative genomic investigations of Exiguobacterium spp. from different sources have been limited. In this study, we employed different molecular approaches for the comparative analysis of 24 isolates from markedly diverse environments including ancient Siberian permafrost and hot springs at Yellowstone National Park. Pulsed-field gel electrophoresis (PFGE) with I-CeuI (an intron-encoded endonuclease), AscI and NotI were optimized for the determination of genomic fingerprints of nuclease-producing isolates. The application of a DNA macroarray for 82 putative stress-response genes yielded strain-specific hybridization profiles. Cluster analyses of 16S rRNA gene sequence data, PFGE I-CeuI restriction patterns and hybridization profiles suggested that Exiguobacterium strains formed two distinct divisions that generally agreed with temperature ranges for growth. With few exceptions (e.g., Greenland ice isolate GIC31), psychrotrophic and thermophilic isolates belonged to different divisions.

Keywords

ExiguobacteriumPFGEMacroarrayPsychrophilic and thermophilic adaptations

Supplementary material

792_2009_243_MOESM1_ESM.doc (346 kb)
Supplementary Table S1.(DOC 345 kb)

Copyright information

© Springer 2009

Authors and Affiliations

  • Tatiana A. Vishnivetskaya
    • 1
    • 3
  • Sophia Kathariou
    • 1
  • James M. Tiedje
    • 2
  1. 1.North Carolina State UniversityRaleighUSA
  2. 2.Center for Microbial EcologyMichigan State UniversityEast LansingUSA
  3. 3.Microbial Ecology and Physiology Group, Biosciences DivisionOak Ridge National LaboratoryOak RidgeUSA