The Exiguobacterium genus: biodiversity and biogeography

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Extremophiles

DOI:https://doi.org/10.1007/s00792-009-0243-5· OSTI ID:963414

Vishnivetskaya, Tatiana A ^[1]; Kathariou, Sophia ^[2]; Tiedje, James M. ^[3]

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1. ORNL
2. North Carolina State University
3. Michigan State University, East Lansing

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.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 963414
• Journal Information: Extremophiles, Journal Name: Extremophiles Journal Issue: 3 Vol. 13
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
BACTERIA
DNA
ELECTROPHORESIS
Exiguobacterium
FOOD PROCESSING
GENES
HOT SPRINGS
HYBRIDIZATION
Macroarray
PERMAFROST
PFGE
Psychrophilic and thermophilic adaptations
SPECIES DIVERSITY
STRAINS
YELLOWSTONE NATIONAL PARK